def Protection_Controller(arg):
# Check Solar
time.sleep(.01) # Wait .01 seconds to prevent segmentation fault
Solar_Voltage = PWM_Measure_Voltage(
'Solar') / Parameters.Voltage_Multiplier # Measure solar volatge
DC_Link_Voltage = PWM_Measure_Voltage(
'DC_Link') / Parameters.Voltage_Multiplier # Measure DC link voltage
if (Solar_Voltage >= Parameters.Solar_VDC_Max
or Solar_Voltage <= Parameters.Solar_VDC_Min):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"),
3) # Stop motor
Transfer_Switch(0) # Switch to grid source
PWM.PWM_Write(
Parameters.PWMPin, Parameters.PID_OLD_INIT *
Parameters.Range) # Reset PWM duty cycle to initial value
DC_Relay(0) # Set solar relay to open
UPS_Error('Error_Solar_Voltage')
if (DC_Link_Voltage >= Parameters.DCLink_VDC_Max
or DC_Link_Voltage <= Parameters.DCLink_VDC_Min):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"),
3) # Stop motor
Transfer_Switch(0) # Switch to grid source
PWM.PWM_Write(
Parameters.PWMPin, Parameters.PID_OLD_INIT *
Parameters.Range) # Reset PWM duty cycle to initial value
DC_Relay(0) # Set solar relay to open position
UPS_Error('Error_DC_Link_Voltage')
# Check Grid
# Check VFD
VFD_Freq = VFD.VFDRead(reg.get("ReadFunc",
{}).get("Output_Frequency")) / 100
VFD_Volt = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Voltage"))
VFD_Amps = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Current")) / 100
VFD_Power = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Power")) / 10
VFD_BusVolt = VFD.VFDRead(reg.get("ReadFunc", {}).get("Bus_Voltage"))
VFD_Temp = VFD.VFDRead(reg.get("ReadFunc", {}).get("Temperature"))
if (VFD_Freq >= Parameters.VFD_Freq_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Freq')
if (VFD_Volt >= Parameters.VFD_Volt_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Volt')
if (VFD_Amps >= Parameters.VFD_Amps_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Amps')
if (VFD_Power >= Parameters.VFD_Power_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Power')
if (VFD_BusVolt >= Parameters.VFD_BusVolt_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_BusVolt')
if (VFD_Temp >= Parameters.VFD_Temp_Max):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Temp')
def PWM_Controller(arg):
global D_PID_OLD
# Get DC link voltage measurement and calculate actual value
DC_Volts = PWM_Measure_Voltage('DC_Link')
DC_Link_Actual_Volts = DC_Volts/Parameters.Voltage_Multiplier
print("DC link voltage=", DC_Actual_Volts)
# Get DC link voltage measurement and calculate actual value
Solar_Volts = PWM_Measure_Voltage('Solar')
Solar_Actual_Volts = Solar_Volts/Parameters.Voltage_Multiplier
if (Solar_Actual_Volts <= Parameters.DCLink_VDC_Min) and (Solar_Actual_Volts >= Parameters.DCLink_VDC_Max):
DC_Relay(0)# Set solar relay to open
time.sleep(10) # Wait 10 seconds
elif Solar_Actual_Volts (DC_Actual_Volts > Parameters.DCLink_VDC_Min) and (Solar_Actual_Volts < Parameters.DCLink_VDC_Max):
DC_Relay(1) # Set solar relay to closed position
time.sleep(5) # Wait 5 seconds
else:
UPS_Error('Error_Solar_Voltage_Relay')
# Calculate the updated DC-DC converter duty cycle
D_PID = PWM_PID(DC_Link_Actual_Volts,D_PID_OLD)
print("Duty cyle=",D_PID)
Convert = int(round(D_PID*Parameters.Range,0)) # Convert to integer from float, value of 0 to 96
PWM.PWM_Write(Parameters.PWMPin,Convert)
# Update the duty cycle variable for the next iteration
D_PID_OLD = D_PID
def PWM_Measure_Voltage(Measurement):
ads = ADS1256()
ads.cal_self()
if Measurement == 'DC_Link':
adsread = ads.read_oneshot(EXT3)
DCVolts = adsread * ads.v_per_digit
elif Measurement == 'Solar':
adsread = ads.read_oneshot(EXT4)
DCVolts = adsread * ads.v_per_digit
else:
UPS_Error('Error_Voltage_Measurement')
return DCVolts
def Protection_Controller(arg):
# Check Solar setpoints
time.sleep(.01)
Solar_Voltage = PWM_Measure_Voltage(
'Solar') / Parameters.Voltage_Multiplier
DC_Link_Voltage = PWM_Measure_Voltage(
'DC_Link') / Parameters.Voltage_Multiplier
if (Solar_Voltage >= Parameters.SolarMax):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
PWM.PWM_Write(Parameters.PWMPin, 0)
UPS_Error('Error_Solar_Voltage')
if (DC_Link_Voltage >= Parameters.DCLinkMax):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
PWM.PWM_Write(Parameters.PWMPin, 0)
UPS_Error('Error_DC_Link_Voltage')
# Check Grid setpoints
# Check VFD setpoint
VFD_Freq = VFD.VFDRead(reg.get("ReadFunc",
{}).get("Output_Frequency")) / 100
VFD_Volt = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Voltage"))
VFD_Amps = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Current")) / 100
VFD_Power = VFD.VFDRead(reg.get("ReadFunc", {}).get("Output_Power")) / 10
VFD_BusVolt = VFD.VFDRead(reg.get("ReadFunc", {}).get("Bus_Voltage"))
VFD_Temp = VFD.VFDRead(reg.get("ReadFunc", {}).get("Temperature"))
if (VFD_Freq >= 61):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Freq')
if (VFD_Volt >= 240):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Volt')
if (VFD_Amps >= 15):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Amps')
if (VFD_Power >= 2000):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Power')
if (VFD_BusVolt >= 400):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_BusVolt')
if (VFD_Temp >= 40):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Temp')
Protection_Sched.enter(10, 1, Protection_Controller, ("", ))
Protection_Sched.run()
def PWM_PID(DC_Voltage, D_PID_OLD):
DC_PID.update(DC_Voltage)
D_update = DC_PID.output
D = D_PID_OLD - D_update
if D > .9:
D_out = .9
elif D < .7:
D_out = .7
elif D <= .8 and D >= .7:
D_out = D
else:
UPS_Error('Error_Duty_Cycle')
print("ErrorD = ", D)
D_out = .5
return D_out
def PWM_PID(DC_Voltage, D_PID_OLD):
DC_PID.update(DC_Voltage) # Run the PID update function
D_update = DC_PID.output # Get the updated PID duty cycle value
D = D_PID_OLD - D_update # Calculate the change in the duty cycle
# Duty cycle protection statement to ensure acceptable operating range
if D > Parameters.D_Max:
D_out = Parameters.D_Max
elif D < Parameters.D_Min:
D_out = Parameters.D_Min
elif D <= Parameters.D_Max and D >= Parameters.D_Min:
D_out = D
else:
UPS_Error('Error_Duty_Cycle')
D_out = Parameters.PID_OLD_INIT # Reset duty cycle to default initial value
return D_out
def PWM_Measure_Voltage(Measurement):
# Connect to ADS1256 chip
ads = ADS1256()
# Calibrate gain and offset
#ads.cal_self()
# Measure DC link or solar voltage
if Measurement == 'DC_Link':
adsread = ads.read_oneshot(EXT3)
DCVolts = adsread * ads.v_per_digit
elif Measurement == 'Solar':
adsread = ads.read_oneshot(EXT4)
DCVolts = adsread * ads.v_per_digit
else:
UPS_Error('Error_Voltage_Measurement')
return DCVolts
def PWM_PID(DC_Voltage, D_PID_OLD):
DC_PID.update(DC_Voltage)
D_update = DC_PID.output
#print("D_update = ",D_update)
D = D_PID_OLD - D_update
#print(D)
if D > .8:
D_out = .8
elif D < .4:
D_out = .4
elif D <= .8 and D >= .4:
D_out = D
else:
UPS_Error('Error_Duty_Cycle')
print("ErrorD = ", D)
D_out = .5
#print(D_out)
return D_out
def Protection_Controller():
# Check Solar setpoints
Solar_Voltage = PWM_Measure_Voltage('Solar')
DC_Link_Voltage = PWM_Measure_Voltage('DC_Link')
if (Solar_Voltage >=Parameters.SolarMax):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
PWM_Output(Parameters.PWMPin,0)
UPS_Error('Error_Solar_Voltage')
if (DC_Link_Voltage >= Parameters.DCLinkMax):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
PWM_Output(Parameters.PWMPin, 0)
UPS_Error('Error_DC_Link_Voltage')
# Check Grid setpoints
# Check VFD setpoint
VFD_Freq = VFD.VFDRead(reg.get("ReadFunc",{}).get("Output_Frequency"))/100
VFD_Volt = VFD.VFDRead(reg.get("ReadFunc",{}).get("Output_Voltage"))
VFD_Amps = VFD.VFDRead(reg.get("ReadFunc",{}).get("Output_Current"))/100
VFD_Power =VFD.VFDRead(reg.get("ReadFunc",{}).get("Output_Power"))/10
VFD_BusVolt = VFD.VFDRead(reg.get("ReadFunc",{}).get("Bus_Voltage"))
VFD_Temp = VFD.VFDRead(reg.get("ReadFunc",{}).get("Temperature"))
if (VFD_Freq >=61):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Freq')
if (VFD_Volt >=240):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Volt')
if (VFD_Amps >=10):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Amps')
if (VFD_Power >=2000):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Power')
if (VFD_BusVolt >=400):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3
UPS_Error('Error_VFD_BusVolt')
if (VFD_Temp >=40):
VFD.VFDWrite(reg.get("WriteFunc", {}).get("Motor_Start_Stop"), 3)
UPS_Error('Error_VFD_Temp')
def PWM_Voltage_Measure(Measurement):
gain = 1 # ADC's Gain parameter
sps = 25 # ADC's SPS parameter
ads1256.start(str(gain), str(sps))
if Measurement == 'DC_Link':
ChannelValue = ads1256.read_channel(3)
ChannelValueVolts = ((
(ChannelValue * 100) / 167.0) / int(gain)) / 1000000.0
DCVolts = ChannelValueVolts
elif Measuremnet == 'Solar':
ChannelValue = ads1256.read_channel(3)
ChannelValueVolts = ((
(ChannelValue * 100) / 167.0) / int(gain)) / 1000000.0
DCVolts = ChannelValueVolts
else:
UPS_Error('Error_Voltage_Measurement')
ads1256.stop()
return DCVolts