Ejemplo n.º 1
0
    def __init__(self):
        self.udref0 = ConstService(tex_name=r'u_{dref0}',
                                   v_str='vd0 + ra*Id0 - xs*Iq0')
        self.uqref0 = ConstService(
            tex_name=r'u_{qref0}',
            v_str='vq0 + ra*Iq0 + xs*Id0',
        )

        # PIvd_y, PIvq_y are Idref, Iqref
        self.PIId = PIController(
            u='Id - PIvd_y',
            kp=self.KpId,
            ki=self.KiId,
        )
        self.PIIq = PIController(
            u='Iq - PIvq_y',
            kp=self.KpIq,
            ki=self.KiIq,
        )

        # udLag_y, uqLag_y are ud, uq
        self.Id.e_str = 'vd + ra*Id - xs*Iq - udLag_y'
        self.Iq.e_str = 'vq + ra*Iq + xs*Id - uqLag_y'

        self.udref = Algeb(
            tex_name=r'u_{dref}',
            info='ud reference',
            v_str='udref0',
            e_str='PIId_y + vd - Iqref * xs - udref',
        )
        self.uqref = Algeb(
            tex_name=r'u_{qref}',
            info='uq reference',
            v_str='uqref0',
            e_str='PIIq_y + vq + Idref * xs - uqref',
        )

        self.udLag = Lag(
            u='udref',
            T=self.Tc,
            K=1,
        )
        self.uqLag = Lag(
            u='uqref',
            T=self.Tc,
            K=1,
        )

        self.ud = AliasState(self.udLag_y)
        self.uq = AliasState(self.uqLag_y)
Ejemplo n.º 2
0
    def __init__(self, system, config):
        TGBase.__init__(self, system, config)

        self.F1 = Lag(
            u='ue * (omega - wref)',
            T=self.T1,
            K=self.K1,
        )

        self.F2 = LeadLag(
            u=self.F1_y,
            T1=self.T2,
            T2=self.T3,
            K=1.0,
        )

        self.HL = GainLimiter(
            u='ue * (paux + pref0 - F2_y)',
            K=1.0,
            R=1.0,
            lower=self.PMIN,
            upper=self.PMAX,
        )
        self.F3 = Lag(
            u=self.HL_y,
            T=self.T4,
            K=1.0,
        )

        self.F4 = Lag(
            u=self.F3_y,
            T=self.T5,
            K=self.K2,
        )

        self.F5 = Lag(
            u=self.F4_y,
            T=self.T6,
            K=self.K3,
        )

        self.pout.e_str = 'ue * ((1-K2)*F3_y + (1-K3)*F4_y + F5_y) - pout'
Ejemplo n.º 3
0
    def __init__(self, system, config):
        TGBase.__init__(self, system, config, add_sn=False)

        # check if K1-K8 sums up to 1
        self._sumK18 = ConstService(v_str='K1+K2+K3+K4+K5+K6+K7+K8',
                                    info='summation of K1-K8',
                                    tex_name=r"\sum_{i=1}^8 K_i")
        self._K18c1 = InitChecker(
            u=self._sumK18,
            info='summation of K1-K8 and 1.0',
            equal=1,
        )

        # check if  `tm0 * (K2 + k4 + K6 + K8) = tm02 *(K1 + K3 + K5 + K7)
        self._tm0K2 = PostInitService(
            info='mul of tm0 and (K2+K4+K6+K8)',
            v_str='zsyn2*tm0*(K2+K4+K6+K8)',
        )
        self._tm02K1 = PostInitService(
            info='mul of tm02 and (K1+K3+K5+K6)',
            v_str='tm02*(K1+K3+K5+K7)',
        )
        self._Pc = InitChecker(
            u=self._tm0K2,
            info='proportionality of tm0 and tm02',
            equal=self._tm02K1,
        )

        self.Sg2 = ExtParam(
            src='Sn',
            model='SynGen',
            indexer=self.syn2,
            allow_none=True,
            default=0.0,
            tex_name='S_{n2}',
            info='Rated power of Syn2',
            unit='MVA',
            export=False,
        )
        self.Sg12 = ParamCalc(
            self.Sg,
            self.Sg2,
            func=np.add,
            tex_name="S_{g12}",
            info='Sum of generator power ratings',
        )
        self.Sn = NumSelect(
            self.Tn,
            fallback=self.Sg12,
            tex_name='S_n',
            info='Turbine or Gen rating',
        )

        self.zsyn2 = FlagValue(
            self.syn2,
            value=None,
            tex_name='z_{syn2}',
            info='Exist flags for syn2',
        )

        self.tm02 = ExtService(
            src='tm',
            model='SynGen',
            indexer=self.syn2,
            tex_name=r'\tau_{m02}',
            info='Initial mechanical input of syn2',
            allow_none=True,
            default=0.0,
        )
        self.tm012 = ConstService(
            info='total turbine power',
            v_str='tm0 + tm02',
        )

        self.tm2 = ExtAlgeb(
            src='tm',
            model='SynGen',
            indexer=self.syn2,
            allow_none=True,
            tex_name=r'\tau_{m2}',
            e_str='zsyn2 * u * (PLP - tm02)',
            info='Mechanical power to syn2',
        )

        self.wd = Algeb(
            info='Generator under speed',
            unit='p.u.',
            tex_name=r'\omega_{dev}',
            v_str='0',
            e_str='(wref - omega) - wd',
        )

        self.LL = LeadLag(
            u=self.wd,
            T1=self.T2,
            T2=self.T1,
            K=self.K,
            info='Signal conditioning for wd',
        )

        # `P0` == `tm0`
        self.vs = Algeb(
            info='Valve speed',
            tex_name='V_s',
            v_str='0',
            e_str='(LL_y + tm012 + paux - IAW_y) / T3 - vs',
        )

        self.HL = HardLimiter(
            u=self.vs,
            lower=self.UC,
            upper=self.UO,
            info='Limiter on valve acceleration',
        )

        self.vsl = Algeb(
            info='Valve move speed after limiter',
            tex_name='V_{sl}',
            v_str='vs * HL_zi + UC * HL_zl + UO * HL_zu',
            e_str='vs * HL_zi + UC * HL_zl + UO * HL_zu - vsl',
        )

        self.IAW = IntegratorAntiWindup(
            u=self.vsl,
            T=1,
            K=1,
            y0=self.tm012,
            lower=self.PMIN,
            upper=self.PMAX,
            info='Valve position integrator',
        )

        self.L4 = Lag(
            u=self.IAW_y,
            T=self.T4,
            K=1,
            info='first process',
        )

        self.L5 = Lag(
            u=self.L4_y,
            T=self.T5,
            K=1,
            info='second (reheat) process',
        )

        self.L6 = Lag(
            u=self.L5_y,
            T=self.T6,
            K=1,
            info='third process',
        )

        self.L7 = Lag(
            u=self.L6_y,
            T=self.T7,
            K=1,
            info='fourth (second reheat) process',
        )

        self.PHP = Algeb(
            info='HP output',
            tex_name='P_{HP}',
            v_str='K1*L4_y + K3*L5_y + K5*L6_y + K7*L7_y',
            e_str='K1*L4_y + K3*L5_y + K5*L6_y + K7*L7_y - PHP',
        )

        self.PLP = Algeb(
            info='LP output',
            tex_name='P_{LP}',
            v_str='K2*L4_y + K4*L5_y + K6*L6_y + K8*L7_y',
            e_str='K2*L4_y + K4*L5_y + K6*L6_y + K8*L7_y - PLP',
        )

        self.pout.e_str = 'PHP - pout'
Ejemplo n.º 4
0
    def __init__(self, system, config):
        Model.__init__(self, system, config)

        self.flags.tds = True
        self.group = 'RenExciter'

        self.config.add(OrderedDict((('kqs', 2),
                                     ('kvs', 2),
                                     ('tpfilt', 0.02),
                                     )))
        self.config.add_extra('_help',
                              kqs='Q PI controller tracking gain',
                              kvs='Voltage PI controller tracking gain',
                              tpfilt='Time const. for Pref filter',
                              )
        self.config.add_extra('_tex',
                              kqs='K_{qs}',
                              kvs='K_{vs}',
                              tpfilt='T_{pfilt}',
                              )

        # --- Sanitize inputs ---
        self.Imaxr = Replace(self.Imax, flt=lambda x: np.less_equal(x, 0), new_val=1e8,
                             tex_name='I_{maxr}')

        # --- Flag switchers ---
        self.SWPF = Switcher(u=self.PFFLAG, options=(0, 1), tex_name='SW_{PF}', cache=True)

        self.SWV = Switcher(u=self.VFLAG, options=(0, 1), tex_name='SW_{V}', cache=True)

        self.SWQ = Switcher(u=self.QFLAG, options=(0, 1), tex_name='SW_{V}', cache=True)

        self.SWP = Switcher(u=self.PFLAG, options=(0, 1), tex_name='SW_{P}', cache=True)

        self.SWPQ = Switcher(u=self.PQFLAG, options=(0, 1), tex_name='SW_{PQ}', cache=True)

        # --- External parameters ---
        self.bus = ExtParam(model='RenGen', src='bus', indexer=self.reg, export=False,
                            info='Retrieved bus idx', vtype=str, default=None,
                            )

        self.buss = DataSelect(self.busr, self.bus, info='selected bus (bus or busr)')

        self.gen = ExtParam(model='RenGen', src='gen', indexer=self.reg, export=False,
                            info='Retrieved StaticGen idx', vtype=str, default=None,
                            )

        self.Sn = ExtParam(model='RenGen', src='Sn', indexer=self.reg,
                           tex_name='S_n', export=False,
                           )

        # --- External variables ---
        self.a = ExtAlgeb(model='Bus',
                          src='a',
                          indexer=self.bus,
                          tex_name=r'\theta',
                          info='Bus voltage angle',
                          )

        self.v = ExtAlgeb(model='Bus',
                          src='v',
                          indexer=self.bus,
                          tex_name=r'V',
                          info='Bus voltage magnitude',
                          )  # check whether to use `bus` or `buss`

        self.Pe = ExtAlgeb(model='RenGen', src='Pe', indexer=self.reg, export=False,
                           info='Retrieved Pe of RenGen')

        self.Qe = ExtAlgeb(model='RenGen', src='Qe', indexer=self.reg, export=False,
                           info='Retrieved Qe of RenGen')

        self.Ipcmd = ExtAlgeb(model='RenGen', src='Ipcmd', indexer=self.reg, export=False,
                              info='Retrieved Ipcmd of RenGen',
                              e_str='-Ipcmd0 + IpHL_y',
                              )

        self.Iqcmd = ExtAlgeb(model='RenGen', src='Iqcmd', indexer=self.reg, export=False,
                              info='Retrieved Iqcmd of RenGen',
                              e_str='-Iqcmd0 - IqHL_y',
                              )

        self.p0 = ExtService(model='RenGen',
                             src='p0',
                             indexer=self.reg,
                             tex_name='P_0',
                             )
        self.q0 = ExtService(model='RenGen',
                             src='q0',
                             indexer=self.reg,
                             tex_name='Q_0',
                             )

        # Initial current commands
        self.Ipcmd0 = ConstService('p0 / v', info='initial Ipcmd')

        self.Iqcmd0 = ConstService('-q0 / v', info='initial Iqcmd')

        # --- Initial power factor angle ---
        # NOTE: if `p0` = 0, `pfaref0` = pi/2, `tan(pfaref0)` = inf
        self.pfaref0 = ConstService(v_str='atan2(q0, p0)', tex_name=r'\Phi_{ref0}',
                                    info='Initial power factor angle',
                                    )
        # flag devices with `p0`=0, which causes `tan(PF) = +inf`
        self.zp0 = ConstService(v_str='Eq(p0, 0)',
                                vtype=float,
                                tex_name='z_{p0}',
                                )

        # --- Discrete components ---
        self.Vcmp = Limiter(u=self.v, lower=self.Vdip, upper=self.Vup, tex_name='V_{cmp}',
                            info='Voltage dip comparator', equal=False,
                            )
        self.Volt_dip = VarService(v_str='1 - Vcmp_zi',
                                   info='Voltage dip flag; 1-dip, 0-normal',
                                   tex_name='z_{Vdip}',
                                   )

        # --- Equations begin ---
        self.s0 = Lag(u=self.v, T=self.Trv, K=1,
                      info='Voltage filter',
                      )
        self.VLower = Limiter(u=self.v, lower=0.01, upper=999, no_upper=True,
                              info='Limiter for lower voltage cap',
                              )
        self.vp = Algeb(tex_name='V_p',
                        info='Sensed lower-capped voltage',
                        v_str='v * VLower_zi + 0.01 * VLower_zl',
                        e_str='v * VLower_zi + 0.01 * VLower_zl - vp',
                        )

        self.pfaref = Algeb(tex_name=r'\Phi_{ref}',
                            info='power factor angle ref',
                            unit='rad',
                            v_str='pfaref0',
                            e_str='pfaref0 - pfaref',
                            )

        self.S1 = Lag(u='Pe', T=self.Tp, K=1, tex_name='S_1', info='Pe filter',
                      )

        # ignore `Qcpf` if `pfaref` is pi/2 by multiplying (1-zp0)
        self.Qcpf = Algeb(tex_name='Q_{cpf}',
                          info='Q calculated from P and power factor',
                          v_str='q0',
                          e_str='(1-zp0) * (S1_y * tan(pfaref) - Qcpf)',
                          diag_eps=True,
                          unit='p.u.',
                          )

        self.Qref = Algeb(tex_name='Q_{ref}',
                          info='external Q ref',
                          v_str='q0',
                          e_str='q0 - Qref',
                          unit='p.u.',
                          )

        self.PFsel = Algeb(v_str='SWPF_s0*Qref + SWPF_s1*Qcpf',
                           e_str='SWPF_s0*Qref + SWPF_s1*Qcpf - PFsel',
                           info='Output of PFFLAG selector',
                           )

        self.PFlim = Limiter(u=self.PFsel, lower=self.QMin, upper=self.QMax)

        self.Qerr = Algeb(tex_name='Q_{err}',
                          info='Reactive power error',
                          v_str='(PFsel*PFlim_zi + QMin*PFlim_zl + QMax*PFlim_zu) - Qe',
                          e_str='(PFsel*PFlim_zi + QMin*PFlim_zl + QMax*PFlim_zu) - Qe - Qerr',
                          )

        self.PIQ = PITrackAWFreeze(u=self.Qerr,
                                   kp=self.Kqp, ki=self.Kqi, ks=self.config.kqs,
                                   lower=self.VMIN, upper=self.VMAX,
                                   freeze=self.Volt_dip,
                                   )

        # If `VFLAG=0`, set the input as `Vref1` (see the NREL report)
        self.Vsel = GainLimiter(u='SWV_s0 * Vref1 + SWV_s1 * PIQ_y',
                                K=1, R=1,
                                lower=self.VMIN, upper=self.VMAX,
                                info='Selection output of VFLAG',
                                )

        # --- Placeholders for `Iqmin` and `Iqmax` ---

        self.s4 = LagFreeze(u='PFsel / vp', T=self.Tiq, K=1,
                            freeze=self.Volt_dip,
                            tex_name='s_4',
                            info='Filter for calculated voltage with freeze',
                            )

        # --- Upper portion - Iqinj calculation ---

        self.Verr = Algeb(info='Voltage error (Vref0)',
                          v_str='Vref0 - s0_y',
                          e_str='Vref0 - s0_y - Verr',
                          tex_name='V_{err}',
                          )
        self.dbV = DeadBand1(u=self.Verr, lower=self.dbd1, upper=self.dbd2,
                             center=0.0,
                             enable='DB_{V}',
                             info='Deadband for voltage error (ref0)'
                             )

        self.pThld = ConstService(v_str='Indicator(Thld > 0)', tex_name='p_{Thld}')

        self.nThld = ConstService(v_str='Indicator(Thld < 0)', tex_name='n_{Thld}')

        self.Thld_abs = ConstService(v_str='abs(Thld)', tex_name='|Thld|')

        self.fThld = ExtendedEvent(self.Volt_dip,
                                   t_ext=self.Thld_abs,
                                   )

        # Gain after dbB
        Iqv = "(dbV_y * Kqv)"
        Iqinj = f'{Iqv} * Volt_dip + ' \
                f'(1 - Volt_dip) * fThld * ({Iqv} * nThld + Iqfrz * pThld)'

        # state transition, output of Iqinj
        self.Iqinj = Algeb(v_str=Iqinj,
                           e_str=Iqinj + ' - Iqinj',
                           tex_name='I_{qinj}',
                           info='Additional Iq signal during under- or over-voltage',
                           )

        # --- Lower portion - active power ---
        self.wg = Algeb(tex_name=r'\omega_g',
                        info='Drive train generator speed',
                        v_str='1.0',
                        e_str='1.0 - wg',
                        )

        self.Pref = Algeb(tex_name='P_{ref}',
                          info='external P ref',
                          v_str='p0 / wg',
                          e_str='p0 / wg - Pref',
                          unit='p.u.',
                          )

        self.pfilt = LagRate(u=self.Pref, T=self.config.tpfilt, K=1,
                             rate_lower=self.dPmin, rate_upper=self.dPmax,
                             info='Active power filter with rate limits',
                             tex_name='P_{filt}',
                             )

        self.Psel = Algeb(tex_name='P_{sel}',
                          info='Output selection of PFLAG',
                          v_str='SWP_s1*wg*pfilt_y + SWP_s0*pfilt_y',
                          e_str='SWP_s1*wg*pfilt_y + SWP_s0*pfilt_y - Psel',
                          )

        # `s5_y` is `Pord`
        self.s5 = LagAWFreeze(u=self.Psel, T=self.Tpord, K=1,
                              lower=self.PMIN, upper=self.PMAX,
                              freeze=self.Volt_dip,
                              tex_name='s5',
                              )

        self.Pord = AliasState(self.s5_y)

        # --- Current limit logic ---

        self.kVq12 = ConstService(v_str='(Iq2 - Iq1) / (Vq2 - Vq1)',
                                  tex_name='k_{Vq12}',
                                  )
        self.kVq23 = ConstService(v_str='(Iq3 - Iq2) / (Vq3 - Vq2)',
                                  tex_name='k_{Vq23}',
                                  )
        self.kVq34 = ConstService(v_str='(Iq4 - Iq3) / (Vq4 - Vq3)',
                                  tex_name='k_{Vq34}',
                                  )

        self.zVDL1 = ConstService(v_str='(Vq1 <= Vq2) & (Vq2 <= Vq3) & (Vq3 <= Vq4) & '
                                        '(Iq1 <= Iq2) & (Iq2 <= Iq3) & (Iq3 <= Iq4)',
                                  tex_name='z_{VDL1}',
                                  info='True if VDL1 is in service',
                                  )

        self.VDL1 = Piecewise(u=self.s0_y,
                              points=('Vq1', 'Vq2', 'Vq3', 'Vq4'),
                              funs=('Iq1',
                                    f'({self.s0_y.name} - Vq1) * kVq12 + Iq1',
                                    f'({self.s0_y.name} - Vq2) * kVq23 + Iq2',
                                    f'({self.s0_y.name} - Vq3) * kVq34 + Iq3',
                                    'Iq4'),
                              tex_name='V_{DL1}',
                              info='Piecewise linear characteristics of Vq-Iq',
                              )

        self.kVp12 = ConstService(v_str='(Ip2 - Ip1) / (Vp2 - Vp1)',
                                  tex_name='k_{Vp12}',
                                  )
        self.kVp23 = ConstService(v_str='(Ip3 - Ip2) / (Vp3 - Vp2)',
                                  tex_name='k_{Vp23}',
                                  )
        self.kVp34 = ConstService(v_str='(Ip4 - Ip3) / (Vp4 - Vp3)',
                                  tex_name='k_{Vp34}',
                                  )

        self.zVDL2 = ConstService(v_str='(Vp1 <= Vp2) & (Vp2 <= Vp3) & (Vp3 <= Vp4) & '
                                        '(Ip1 <= Ip2) & (Ip2 <= Ip3) & (Ip3 <= Ip4)',
                                  tex_name='z_{VDL2}',
                                  info='True if VDL2 is in service',
                                  )

        self.VDL2 = Piecewise(u=self.s0_y,
                              points=('Vp1', 'Vp2', 'Vp3', 'Vp4'),
                              funs=('Ip1',
                                    f'({self.s0_y.name} - Vp1) * kVp12 + Ip1',
                                    f'({self.s0_y.name} - Vp2) * kVp23 + Ip2',
                                    f'({self.s0_y.name} - Vp3) * kVp34 + Ip3',
                                    'Ip4'),
                              tex_name='V_{DL2}',
                              info='Piecewise linear characteristics of Vp-Ip',
                              )

        self.fThld2 = ExtendedEvent(self.Volt_dip,
                                    t_ext=self.Thld2,
                                    extend_only=True,
                                    )

        self.VDL1c = VarService(v_str='Lt(VDL1_y, Imaxr)')

        self.VDL2c = VarService(v_str='Lt(VDL2_y, Imaxr)')

        # `Iqmax` not considering mode or `Thld2`
        Iqmax1 = '(zVDL1*(VDL1c*VDL1_y + (1-VDL1c)*Imaxr) + 1e8*(1-zVDL1))'

        # `Ipmax` not considering mode or `Thld2`
        Ipmax1 = '(zVDL2*(VDL2c*VDL2_y + (1-VDL2c)*Imaxr) + 1e8*(1-zVDL2))'

        Ipmax2sq0 = '(Imax**2 - Iqcmd0**2)'

        Ipmax2sq = '(Imax**2 - IqHL_y**2)'

        # `Ipmax20`-squared (non-negative)
        self.Ipmax2sq0 = ConstService(v_str=f'Piecewise((0, Le({Ipmax2sq0}, 0.0)), ({Ipmax2sq0}, True), \
                                              evaluate=False)',
                                      tex_name='I_{pmax20,nn}^2',
                                      )

        self.Ipmax2sq = VarService(v_str=f'Piecewise((0, Le({Ipmax2sq}, 0.0)), ({Ipmax2sq}, True), \
                                           evaluate=False)',
                                   tex_name='I_{pmax2}^2',
                                   )

        Ipmax = f'((1-fThld2) * (SWPQ_s0*sqrt(Ipmax2sq) + SWPQ_s1*{Ipmax1}))'

        Ipmax0 = f'((1-fThld2) * (SWPQ_s0*sqrt(Ipmax2sq0) + SWPQ_s1*{Ipmax1}))'

        self.Ipmax = Algeb(v_str=f'{Ipmax0}',
                           e_str=f'{Ipmax} + (fThld2 * Ipmaxh) - Ipmax',
                           tex_name='I_{pmax}',
                           diag_eps=True,
                           info='Upper limit on Ipcmd',
                           )

        self.Ipmaxh = VarHold(self.Ipmax, hold=self.fThld2)

        Iqmax2sq = '(Imax**2 - IpHL_y**2)'

        Iqmax2sq0 = '(Imax**2 - Ipcmd0**2)'  # initialization equation by using `Ipcmd0`

        self.Iqmax2sq0 = ConstService(v_str=f'Piecewise((0, Le({Iqmax2sq0}, 0.0)), ({Iqmax2sq0}, True), \
                                              evaluate=False)',
                                      tex_name='I_{qmax,nn}^2',
                                      )

        self.Iqmax2sq = VarService(v_str=f'Piecewise((0, Le({Iqmax2sq}, 0.0)), ({Iqmax2sq}, True), \
                                           evaluate=False)',
                                   tex_name='I_{qmax2}^2')

        self.Iqmax = Algeb(v_str=f'(SWPQ_s0*{Iqmax1} + SWPQ_s1*sqrt(Iqmax2sq0))',
                           e_str=f'(SWPQ_s0*{Iqmax1} + SWPQ_s1*sqrt(Iqmax2sq)) - Iqmax',
                           tex_name='I_{qmax}',
                           info='Upper limit on Iqcmd',
                           )

        self.Iqmin = ApplyFunc(self.Iqmax, lambda x: -x, cache=False,
                               tex_name='I_{qmin}',
                               info='Lower limit on Iqcmd',
                               )

        self.Ipmin = ConstService(v_str='0.0', tex_name='I_{pmin}',
                                  info='Lower limit on Ipcmd',
                                  )

        self.PIV = PITrackAWFreeze(u='Vsel_y - s0_y * SWV_s0',
                                   x0='-SWQ_s1 * Iqcmd0',
                                   kp=self.Kvp, ki=self.Kvi, ks=self.config.kvs,
                                   lower=self.Iqmin, upper=self.Iqmax,
                                   freeze=self.Volt_dip,
                                   )

        self.Qsel = Algeb(info='Selection output of QFLAG',
                          v_str='SWQ_s1 * PIV_y + SWQ_s0 * s4_y',
                          e_str='SWQ_s1 * PIV_y + SWQ_s0 * s4_y - Qsel',
                          tex_name='Q_{sel}',
                          )

        # `IpHL_y` is `Ipcmd`
        self.IpHL = GainLimiter(u='s5_y / vp',
                                K=1, R=1,
                                lower=self.Ipmin, upper=self.Ipmax,
                                )

        # `IqHL_y` is `Iqcmd`
        self.IqHL = GainLimiter(u='Qsel + Iqinj',
                                K=1, R=1,
                                lower=self.Iqmin, upper=self.Iqmax)
Ejemplo n.º 5
0
    def __init__(self, system, config):
        Model.__init__(self, system, config)

        self.flags.tds = True
        self.group = 'RenTorque'

        self.kp1 = ConstService(v_str='(sp2 - sp1) / (p2 - p1)',
                                tex_name='k_{p1}',
                                )
        self.kp2 = ConstService(v_str='(sp3 - sp2) / (p3 - p2)',
                                tex_name='k_{p2}',
                                )
        self.kp3 = ConstService(v_str='(sp4 - sp3) / (p4 - p3)',
                                tex_name='k_{p3}',
                                )

        self.rea = ExtParam(model='RenPitch', src='rea', indexer=self.rep, export=False,
                            )

        self.rego = ExtParam(model='RenAerodynamics', src='rego', indexer=self.rea,
                             export=False,
                             )

        self.ree = ExtParam(model='RenGovernor', src='ree', indexer=self.rego,
                            export=False,
                            )

        self.reg = ExtParam(model='RenExciter', src='reg', indexer=self.ree,
                            export=False,)

        self.Sngo = ExtParam(model='RenGovernor', src='Sn', indexer=self.rego,
                             tex_name='S_{n,go}', export=False,
                             )
        self.Sn = NumSelect(self.Tn,
                            fallback=self.Sngo,
                            tex_name='S_n',
                            info='Turbine or RenGovernor rating',
                            )

        self.Pe = ExtAlgeb(model='RenGen', src='Pe', indexer=self.reg,
                           tex_name='P_e', export=False,
                           )

        self.s1 = Lag(u=self.Pe, T=self.Tp, K=1.0, tex_name='s_1',
                      info='Pe filter',
                      )

        self.fPe = Piecewise(u=self.s1_y,
                             points=('p1', 'p2', 'p3', 'p4'),
                             funs=('sp1',
                                   f'sp1 + ({self.s1_y.name} - p1) * kp1',
                                   f'sp2 + ({self.s1_y.name} - p2) * kp2',
                                   f'sp3 + ({self.s1_y.name} - p3) * kp3',
                                   'sp4'),
                             tex_name='f_{Pe}',
                             info='Piecewise Pe to wref mapping',
                             )

        # Overwrite `wg` and `wt` initial values in turbine governors
        self.wg = ExtState(model='RenGovernor', src='wg', indexer=self.rego,
                           tex_name=r'\omega_g', export=False,
                           v_str='fPe_y',
                           v_setter=True,
                           )

        self.wt = ExtState(model='RenGovernor', src='wt', indexer=self.rego,
                           tex_name=r'\omega_t', export=False,
                           v_str='fPe_y',
                           v_setter=True,
                           )

        self.s3_y = ExtState(model='RenGovernor', src='s3_y', indexer=self.rego,
                             tex_name='y_{s3}', export=False,
                             v_str='Pref0 / wg / Kshaft',
                             v_setter=True,
                             )

        self.w0 = ExtParam(model='RenGovernor', src='w0', indexer=self.rego,
                           tex_name=r'\omega_0', export=False,
                           )

        self.Kshaft = ExtService(model='RenGovernor', src='Kshaft', indexer=self.rego,
                                 tex_name='K_{shaft}',
                                 )

        self.wr0 = ExtAlgeb(model='RenGovernor', src='wr0', indexer=self.rego,
                            tex_name=r'\omega_{r0}', export=False,
                            info='Retrieved initial w0 from RenGovernor',
                            v_str='fPe_y',
                            e_str='-w0 + fPe_y',
                            v_setter=True,
                            ename='dwr',
                            tex_ename=r'\Delta \omega_r',
                            )

        self.s2 = Lag(u=self.fPe_y, T=self.Twref, K=1.0,
                      tex_name='s_2', info='speed filter',
                      )

        self.SWT = Switcher(u=self.Tflag, options=(0, 1),
                            tex_name='SW_{T}',
                            cache=True,
                            )

        self.Tsel = Algeb(tex_name='T_{sel}',
                          info='Output after Tflag selector',
                          discrete=self.SWT
                          )
        self.Tsel.v_str = 'SWT_s1 * (Pe - Pref0) / wg +' \
                          'SWT_s0 * (s2_y - wg)'
        self.Tsel.e_str = f'{self.Tsel.v_str} - Tsel'

        self.PI = PIAWHardLimit(u=self.Tsel, kp=self.Kpp, ki=self.Kip,
                                aw_lower=self.Temin, aw_upper=self.Temax,
                                lower=self.Temin, upper=self.Temax,
                                tex_name='PI',
                                info='PI controller',
                                x0='Pref0 / fPe_y',
                                )

        # Note:
        #   Reset `wg` of REECA1 to 1.0 becase `wg` has already been multiplied
        #   in the toeque model.
        #   This effectively sets `PFLAG` to 0 if the torque model is connected.

        self.wge = ExtAlgeb(model='RenExciter', src='wg', indexer=self.ree,
                            tex_name=r'\omega_{ge}', export=False,
                            v_str='1.0',
                            e_str='-fPe_y + 1',
                            v_setter=True,
                            ename='dwg',
                            tex_ename=r'\Delta \omega_g',
                            )

        self.Pref0 = ExtService(model='RenExciter', src='p0', indexer=self.ree,
                                tex_name='P_{ref0}',
                                )

        self.Pref = ExtAlgeb(model='RenExciter', src='Pref', indexer=self.ree,
                             tex_name='P_{ref}', export=False,
                             e_str='-Pref0 / wge + PI_y * wg',
                             v_str='PI_y * wg',
                             v_setter=True,
                             ename='Pref',
                             tex_ename='P_{ref}',
                             )
Ejemplo n.º 6
0
    def __init__(self, system, config):
        Model.__init__(self, system, config)

        self.group = 'RenPlant'
        self.flags.tds = True

        self.config.add(OrderedDict((
            ('kqs', 2),
            ('ksg', 2),
            ('freeze', 1),
        )))

        self.config.add_extra(
            '_help',
            kqs='Tracking gain for reactive power PI controller',
            ksg='Tracking gain for active power PI controller',
            freeze='Voltage dip freeze flag; 1-enable, 0-disable',
        )
        self.config.add_extra('_tex',
                              kqs='K_{qs}',
                              ksg='K_{sg}',
                              freeze='f_{rz}')

        # --- from RenExciter ---
        self.reg = ExtParam(
            model='RenExciter',
            src='reg',
            indexer=self.ree,
            export=False,
            info='Retrieved RenGen idx',
            vtype=str,
            default=None,
        )
        self.Pext = ExtAlgeb(
            model='RenExciter',
            src='Pref',
            indexer=self.ree,
            info='Pref from RenExciter renamed as Pext',
            tex_name='P_{ext}',
        )

        self.Qext = ExtAlgeb(
            model='RenExciter',
            src='Qref',
            indexer=self.ree,
            info='Qref from RenExciter renamed as Qext',
            tex_name='Q_{ext}',
        )

        # --- from RenGen ---
        self.bus = ExtParam(
            model='RenGen',
            src='bus',
            indexer=self.reg,
            export=False,
            info='Retrieved bus idx',
            vtype=str,
            default=None,
        )

        self.buss = DataSelect(self.busr,
                               self.bus,
                               info='selected bus (bus or busr)')

        self.busfreq = DeviceFinder(self.busf, link=self.buss, idx_name='bus')

        # from Bus
        self.v = ExtAlgeb(
            model='Bus',
            src='v',
            indexer=self.buss,
            tex_name='V',
            info='Bus (or busr, if given) terminal voltage',
        )

        self.a = ExtAlgeb(
            model='Bus',
            src='a',
            indexer=self.buss,
            tex_name=r'\theta',
            info='Bus (or busr, if given) phase angle',
        )

        self.v0 = ExtService(
            model='Bus',
            src='v',
            indexer=self.buss,
            tex_name="V_0",
            info='Initial bus voltage',
        )

        # from BusFreq
        self.f = ExtAlgeb(model='FreqMeasurement',
                          src='f',
                          indexer=self.busfreq,
                          export=False,
                          info='Bus frequency',
                          unit='p.u.')

        # from Line
        self.bus1 = ExtParam(
            model='ACLine',
            src='bus1',
            indexer=self.line,
            export=False,
            info='Retrieved Line.bus1 idx',
            vtype=str,
            default=None,
        )

        self.bus2 = ExtParam(
            model='ACLine',
            src='bus2',
            indexer=self.line,
            export=False,
            info='Retrieved Line.bus2 idx',
            vtype=str,
            default=None,
        )
        self.r = ExtParam(
            model='ACLine',
            src='r',
            indexer=self.line,
            export=False,
            info='Retrieved Line.r',
            vtype=str,
            default=None,
        )

        self.x = ExtParam(
            model='ACLine',
            src='x',
            indexer=self.line,
            export=False,
            info='Retrieved Line.x',
            vtype=str,
            default=None,
        )

        self.v1 = ExtAlgeb(
            model='ACLine',
            src='v1',
            indexer=self.line,
            tex_name='V_1',
            info='Voltage at Line.bus1',
        )

        self.v2 = ExtAlgeb(
            model='ACLine',
            src='v2',
            indexer=self.line,
            tex_name='V_2',
            info='Voltage at Line.bus2',
        )

        self.a1 = ExtAlgeb(
            model='ACLine',
            src='a1',
            indexer=self.line,
            tex_name=r'\theta_1',
            info='Angle at Line.bus1',
        )

        self.a2 = ExtAlgeb(
            model='ACLine',
            src='a2',
            indexer=self.line,
            tex_name=r'\theta_2',
            info='Angle at Line.bus2',
        )

        # -- begin services ---

        self.Isign = CurrentSign(self.bus,
                                 self.bus1,
                                 self.bus2,
                                 tex_name='I_{sign}')

        Iline = '(Isign * (v1*exp(1j*a1) - v2*exp(1j*a2)) / (r + 1j*x))'

        self.Iline = VarService(
            v_str=Iline,
            vtype=complex,
            info='Complex current from bus1 to bus2',
            tex_name='I_{line}',
        )

        self.Iline0 = ConstService(
            v_str='Iline',
            vtype=complex,
            info='Initial complex current from bus1 to bus2',
            tex_name='I_{line0}',
        )

        Pline = 're(Isign * v1*exp(1j*a1) * conj((v1*exp(1j*a1) - v2*exp(1j*a2)) / (r + 1j*x)))'

        self.Pline = VarService(
            v_str=Pline,
            vtype=float,
            info='Complex power from bus1 to bus2',
            tex_name='P_{line}',
        )

        self.Pline0 = ConstService(
            v_str='Pline',
            vtype=float,
            info='Initial vomplex power from bus1 to bus2',
            tex_name='P_{line0}',
        )

        Qline = 'im(Isign * v1*exp(1j*a1) * conj((v1*exp(1j*a1) - v2*exp(1j*a2)) / (r + 1j*x)))'

        self.Qline = VarService(
            v_str=Qline,
            vtype=float,
            info='Complex power from bus1 to bus2',
            tex_name='Q_{line}',
        )

        self.Qline0 = ConstService(
            v_str='Qline',
            vtype=float,
            info='Initial complex power from bus1 to bus2',
            tex_name='Q_{line0}',
        )

        self.Rcs = NumSelect(
            self.Rc,
            self.r,
            info='Line R (Rc if provided, otherwise line.r)',
            tex_name='R_{cs}',
        )

        self.Xcs = NumSelect(
            self.Xc,
            self.x,
            info='Line X (Xc if provided, otherwise line.x)',
            tex_name='X_{cs}',
        )

        self.Vcomp = VarService(
            v_str='abs(v*exp(1j*a) - (Rcs + 1j * Xcs) * Iline)',
            info='Voltage after Rc/Xc compensation',
            tex_name='V_{comp}')

        self.SWVC = Switcher(u=self.VCFlag,
                             options=(0, 1),
                             tex_name='SW_{VC}',
                             cache=True)

        self.SWRef = Switcher(u=self.RefFlag,
                              options=(0, 1),
                              tex_name='SW_{Ref}',
                              cache=True)

        self.SWF = Switcher(u=self.Fflag,
                            options=(0, 1),
                            tex_name='SW_{F}',
                            cache=True)

        self.SWPL = Switcher(u=self.PLflag,
                             options=(0, 1),
                             tex_name='SW_{PL}',
                             cache=True)

        VCsel = '(SWVC_s1 * Vcomp + SWVC_s0 * (Qline * Kc + v))'

        self.Vref0 = ConstService(
            v_str='(SWVC_s1 * Vcomp + SWVC_s0 * (Qline0 * Kc + v))',
            tex_name='V_{ref0}',
        )

        self.s0 = Lag(
            VCsel,
            T=self.Tfltr,
            K=1,
            tex_name='s_0',
            info='V filter',
        )  # s0_y is the filter output of voltage deviation

        self.s1 = Lag(self.Qline, T=self.Tfltr, K=1, tex_name='s_1')

        self.Vref = Algeb(v_str='Vref0',
                          e_str='Vref0 - Vref',
                          tex_name='Q_{ref}')

        self.Qlinef = Algeb(v_str='Qline0',
                            e_str='Qline0 - Qlinef',
                            tex_name='Q_{linef}')

        Refsel = '(SWRef_s0 * (Qlinef - s1_y) + SWRef_s1 * (Vref - s0_y))'

        self.Refsel = Algeb(v_str=Refsel,
                            e_str=f'{Refsel} - Refsel',
                            tex_name='R_{efsel}')

        self.dbd = DeadBand1(
            u=self.Refsel,
            lower=self.dbd1,
            upper=self.dbd2,
            center=0.0,
            tex_name='d^{bd}',
        )

        # --- e Hardlimit and hold logic ---
        self.eHL = Limiter(
            u=self.dbd_y,
            lower=self.emin,
            upper=self.emax,
            tex_name='e_{HL}',
            info='Hardlimit on deadband output',
        )

        self.zf = VarService(
            v_str='Indicator(v < Vfrz) * freeze',
            tex_name='z_f',
            info='PI Q input freeze signal',
        )

        self.enf = Algeb(
            tex_name='e_{nf}',
            info='e Hardlimit output before freeze',
            v_str='dbd_y*eHL_zi + emax*eHL_zu + emin*eHL_zl',
            e_str='dbd_y*eHL_zi + emax*eHL_zu + emin*eHL_zl - enf',
        )

        # --- hold of `enf` when v < vfrz

        self.eHld = VarHold(
            u=self.enf,
            hold=self.zf,
            tex_name='e_{hld}',
            info='e Hardlimit output after conditional hold',
        )

        self.s2 = PITrackAW(
            u='eHld',
            kp=self.Kp,
            ki=self.Ki,
            ks=self.config.kqs,
            lower=self.Qmin,
            upper=self.Qmax,
            info='PI controller for eHL output',
            tex_name='s_2',
        )

        self.s3 = LeadLag(
            u=self.s2_y,
            T1=self.Tft,
            T2=self.Tfv,
            K=1,
            tex_name='s_3',
        )  # s3_y == Qext

        # Active power part

        self.s4 = Lag(
            self.Pline,
            T=self.Tp,
            K=1,
            tex_name='s_4',
            info='Pline filter',
        )

        self.Freq_ref = ConstService(v_str='1.0',
                                     tex_name='f_{ref}',
                                     info='Initial Freq_ref')
        self.ferr = Algeb(
            tex_name='f_{err}',
            info='Frequency deviation',
            unit='p.u. (Hz)',
            v_str='(Freq_ref - f)',
            e_str='(Freq_ref - f) - ferr',
        )

        self.fdbd = DeadBand1(
            u=self.ferr,
            center=0.0,
            lower=self.fdbd1,
            upper=self.fdbd2,
            tex_name='f^{dbd}',
            info='frequency error deadband',
        )

        self.fdlt0 = LessThan(
            self.fdbd_y,
            0.0,
            tex_name='f_{dlt0}',
            info='frequency deadband output less than zero',
        )

        fdroop = '(fdbd_y * Ddn * fdlt0_z1 + fdbd_y * Dup * fdlt0_z0)'

        self.Plant_pref = Algeb(
            tex_name='P_{ref}',
            info='Plant P ref',
            v_str='Pline0',
            e_str='Pline0 - Plant_pref',
        )

        self.Plerr = Algeb(
            tex_name='P_{lerr}',
            info='Pline error',
            v_str='- s4_y + Plant_pref',
            e_str='- s4_y + Plant_pref - Plerr',
        )

        self.Perr = Algeb(
            tex_name='P_{err}',
            info='Power error before fe limits',
            v_str=f'{fdroop} + Plerr * SWPL_s1',
            e_str=f'{fdroop} + Plerr * SWPL_s1 - Perr',
        )

        self.feHL = Limiter(
            self.Perr,
            lower=self.femin,
            upper=self.femax,
            tex_name='f_{eHL}',
            info='Limiter for power (frequency) error',
        )

        feout = '(Perr * feHL_zi + femin * feHL_zl + femax * feHL_zu)'
        self.s5 = PITrackAW(
            u=feout,
            kp=self.Kpg,
            ki=self.Kig,
            ks=self.config.ksg,
            lower=self.Pmin,
            upper=self.Pmax,
            tex_name='s_5',
            info='PI for fe limiter output',
        )

        self.s6 = Lag(
            u=self.s5_y,
            T=self.Tg,
            K=1,
            tex_name='s_6',
            info='Output filter for Pext',
        )

        Qext = '(s3_y)'

        Pext = '(SWF_s1 * s6_y)'

        self.Pext.e_str = Pext

        self.Qext.e_str = Qext
Ejemplo n.º 7
0
    def __init__(self, system, config):
        Model.__init__(self, system, config)
        self.flags.tds = True
        self.group = 'RenGen'

        self.a = ExtAlgeb(model='Bus',
                          src='a',
                          indexer=self.bus,
                          tex_name=r'\theta',
                          info='Bus voltage angle',
                          e_str='-Pe',
                          )

        self.v = ExtAlgeb(model='Bus',
                          src='v',
                          indexer=self.bus,
                          tex_name=r'V',
                          info='Bus voltage magnitude',
                          e_str='-Qe',
                          )

        self.p0s = ExtService(model='StaticGen',
                              src='p',
                              indexer=self.gen,
                              tex_name='P_{0s}',
                              info='initial P of the static gen',
                              )
        self.q0s = ExtService(model='StaticGen',
                              src='q',
                              indexer=self.gen,
                              tex_name='Q_{0s}',
                              info='initial Q of the static gen',
                              )
        self.p0 = ConstService(v_str='p0s * gammap',
                               tex_name='P_0',
                               info='initial P of this gen',
                               )
        self.q0 = ConstService(v_str='q0s * gammaq',
                               tex_name='Q_0',
                               info='initial Q of this gen',
                               )
        self.ra = ExtParam(model='StaticGen',
                           src='ra',
                           indexer=self.gen,
                           tex_name='r_a',
                           export=False,
                           )
        self.xs = ExtParam(model='StaticGen',
                           src='xs',
                           indexer=self.gen,
                           tex_name='x_s',
                           export=False,
                           )

        # --- INITIALIZATION ---
        self.q0gt0 = ConstService('Indicator(q0> 0)', tex_name='z_{q0>0}',
                                  info='flags for q0 below zero',
                                  )
        self.q0lt0 = ConstService('Indicator(q0< 0)', tex_name='z_{q0<0}',
                                  info='flags for q0 below zero',
                                  )

        self.Ipcmd0 = ConstService('p0 / v', info='initial Ipcmd',
                                   tex_name='I_{pcmd0}',
                                   )

        self.Iqcmd0 = ConstService('-q0 / v', info='initial Iqcmd',
                                   tex_name='I_{qcmd0}',
                                   )

        self.Ipcmd = Algeb(tex_name='I_{pcmd}',
                           info='current component for active power',
                           e_str='Ipcmd0 - Ipcmd', v_str='Ipcmd0')

        self.Iqcmd = Algeb(tex_name='I_{qcmd}',
                           info='current component for reactive power',
                           e_str='Iqcmd0 - Iqcmd', v_str='Iqcmd0')

        # reactive power management

        # rate limiting logic (for fault recovery, although it does not detect any recovery)
        #   - activate upper limit when q0 > 0 (self.q0gt0)
        #   - activate lower limit when q0 < 0 (self.q0lt0)

        self.S1 = LagAntiWindupRate(u=self.Iqcmd,
                                    T=self.Tg, K=-1,
                                    lower=-9999, upper=9999, no_lower=True, no_upper=True,
                                    rate_lower=self.Iqrmin, rate_upper=self.Iqrmax,
                                    rate_lower_cond=self.q0lt0, rate_upper_cond=self.q0gt0,
                                    tex_name='S_1',
                                    info='Iqcmd delay',
                                    )  # output `S1_y` == `Iq`

        # piece-wise gain for low voltage active current mgnt.
        self.kLVG = ConstService(v_str='1 / (Lvpnt1 - Lvpnt0)',
                                 tex_name='k_{LVG}',
                                 )

        self.LVG = Piecewise(u=self.v, points=('Lvpnt0', 'Lvpnt1'),
                             funs=('0', '(v - Lvpnt0) * kLVG', '1'),
                             info='Ip gain during low voltage',
                             tex_name='L_{VG}',
                             )

        # piece-wise gain for LVPL
        self.kLVPL = ConstService(v_str='Lvplsw * Lvpl1 / (Brkpt - Zerox)',
                                  tex_name='k_{LVPL}',
                                  )

        self.S2 = Lag(u=self.v, T=self.Tfltr, K=1.0,
                      info='Voltage filter with no anti-windup',
                      tex_name='S_2',
                      )
        self.LVPL = Piecewise(u=self.S2_y,
                              points=('Zerox', 'Brkpt'),
                              funs=('0 + 9999*(1-Lvplsw)',
                                    '(S2_y - Zerox) * kLVPL + 9999 * (1-Lvplsw)',
                                    '9999'),
                              info='Low voltage Ipcmd upper limit',
                              tex_name='L_{VPL}',
                              )

        self.S0 = LagAntiWindupRate(u=self.Ipcmd, T=self.Tg, K=1,
                                    upper=self.LVPL_y, rate_upper=self.Rrpwr,
                                    lower=-9999, rate_lower=-9999,
                                    no_lower=True, rate_no_lower=True,
                                    tex_name='S_0',
                                    )  # `S0_y` is the output `Ip` in the block diagram

        self.Ipout = Algeb(e_str='S0_y * LVG_y -Ipout',
                           v_str='Ipcmd * LVG_y',
                           info='Output Ip current',
                           tex_name='I_{pout}',
                           )

        # high voltage part
        self.HVG = GainLimiter(u='v - Volim', K=self.Khv, info='High voltage gain block',
                               lower=0, upper=999, no_upper=True,
                               tex_name='H_{VG}'
                               )
        self.HVG.lim.no_warn = True

        self.Iqout = GainLimiter(u='S1_y- HVG_y', K=1, lower=self.Iolim, upper=9999,
                                 no_upper=True, info='Iq output block',
                                 tex_name='I^{qout}',
                                 )  # `Iqout_y` is the final Iq output

        self.Pe = Algeb(tex_name='P_e', info='Active power output',
                        v_str='p0', e_str='Ipout * v - Pe')
        self.Qe = Algeb(tex_name='Q_e', info='Reactive power output',
                        v_str='q0', e_str='Iqout_y * v - Qe')
Ejemplo n.º 8
0
    def __init__(self, system, config):
        PSSBase.__init__(self, system, config)

        # ALL THE FOLLOWING IS FOR INPUT 2
        # retrieve indices of bus and bus freq
        self.buss2 = DataSelect(self.busr2,
                                self.bus,
                                info='selected bus (bus or busr)')

        self.busfreq2 = DeviceFinder(self.busf2,
                                     link=self.buss2,
                                     idx_name='bus',
                                     default_model='BusFreq',
                                     info='bus frequency idx')

        # from Bus
        self.v2 = ExtAlgeb(
            model='Bus',
            src='v',
            indexer=self.buss2,
            tex_name=r'V',
            info='Bus (or busr2, if given) terminal voltage',
        )

        # from BusFreq 2
        self.f2 = ExtAlgeb(model='FreqMeasurement',
                           src='f',
                           indexer=self.busfreq2,
                           export=False,
                           info='Bus frequency 2')

        # Config
        self.config.add(OrderedDict([('freq_model', 'BusFreq')]))
        self.config.add_extra(
            '_help', {'freq_model': 'default freq. measurement model'})
        self.config.add_extra('_alt', {'freq_model': ('BusFreq', )})

        self.busf.model = self.config.freq_model
        self.busf2.model = self.config.freq_model

        # input signal switch
        self.dv = Derivative(self.v)
        self.dv2 = Derivative(self.v2)

        self.SnSb = ExtService(
            model='SynGen',
            src='M',
            indexer=self.syn,
            attr='pu_coeff',
            info='Machine base to sys base factor for power',
            tex_name='(Sb/Sn)')

        self.SW = Switcher(
            u=self.MODE,
            options=[0, 1, 2, 3, 4, 5, 6, np.nan],
        )
        self.SW2 = Switcher(
            u=self.MODE2,
            options=[0, 1, 2, 3, 4, 5, 6, np.nan],
        )

        # Input signals
        self.sig = Algeb(
            tex_name='S_{ig}',
            info='Input signal',
        )
        self.sig.v_str = 'SW_s1*(omega-1) + SW_s2*0 + SW_s3*(tm0/SnSb) + ' \
                         'SW_s4*(tm-tm0) + SW_s5*v + SW_s6*0'
        self.sig.e_str = 'SW_s1*(omega-1) + SW_s2*(f-1) + SW_s3*(te/SnSb) + ' \
                         'SW_s4*(tm-tm0) + SW_s5*v + SW_s6*dv_v - sig'

        self.sig2 = Algeb(
            tex_name='S_{ig2}',
            info='Input signal 2',
        )
        self.sig2.v_str = 'SW2_s1*(omega-1) + SW2_s2*0 + SW2_s3*(tm0/SnSb) + ' \
                          'SW2_s4*(tm-tm0) + SW2_s5*v2 + SW2_s6*0'
        self.sig2.e_str = 'SW2_s1*(omega-1) + SW2_s2*(f2-1) + SW2_s3*(te/SnSb) + ' \
                          'SW2_s4*(tm-tm0) + SW2_s5*v2 + SW2_s6*dv2_v - sig2'

        self.L1 = Lag(
            u=self.sig,
            K=self.K1,
            T=self.T1,
            info='Transducer 1',
        )
        self.L2 = Lag(
            u=self.sig2,
            K=self.K2,
            T=self.T2,
            info='Transducer 2',
        )
        self.IN = Algeb(
            tex_name='I_N',
            info='Sum of inputs',
            v_str='L1_y + L2_y',
            e_str='L1_y + L2_y - IN',
        )

        self.WO = WashoutOrLag(
            u=self.IN,
            K=self.T3,
            T=self.T4,
        )

        self.LL1 = LeadLag(
            u=self.WO_y,
            T1=self.T5,
            T2=self.T6,
            zero_out=True,
        )

        self.LL2 = LeadLag(
            u=self.LL1_y,
            T1=self.T7,
            T2=self.T8,
            zero_out=True,
        )

        self.LL3 = LeadLag(
            u=self.LL2_y,
            T1=self.T9,
            T2=self.T10,
            zero_out=True,
        )

        self.VSS = GainLimiter(u=self.LL3_y,
                               K=1,
                               R=1,
                               lower=self.LSMIN,
                               upper=self.LSMAX)

        self.VOU = ConstService(v_str='VCUr + v0')
        self.VOL = ConstService(v_str='VCLr + v0')

        self.OLIM = Limiter(u=self.v,
                            lower=self.VOL,
                            upper=self.VOU,
                            info='output limiter')

        self.vsout.e_str = 'OLIM_zi * VSS_y - vsout'