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In order to run the example model, the following steps must be passed. The model execution provided below includes several test scenarios to convert different control aspects of a PELab unit.

Test sequences and scenarios

• Make the power and control configurations detailed in figure 9 and figure 10

• Open the model attached to this page using RT-LAB.

Open

Figure 16. Demo model opened in RT-LAB environment

• Build and run the model in RT-LAB

• Set the maximum voltage of the DC power supply to 500 V and current to 15 A

• Set the voltage rise time to 15 s or any equivalent slew rate which will ensure smooth pre-charge of the DC-link capacitors

• Enable the output of the DC power supply and wait until the voltage reaches to 500 V. On the “Voltages” scope, the following results must be observed

Open

Figure 17. Status of the voltages after pre-charging the DC links of the PELab power modules

• Set the reference signal of both power modules to 60 Hz

• Set the switching frequency to 20 kHz for both power modules

• Increase the modulation index of both modules to 0.5

• Enable the PWM modulators for both power modules

• Observe the modulation index of each module through the following scopes. The index must be the same as the reference

• Monitor the voltages and currents using the dedicated scopes in the console

• Use an oscilloscope (Tektronix was used in this demo) to monitor the phase voltage, line-to-line voltage, and phase current of the first power module

• Set the switching frequency to 30 kHz for the first power modules

• Prepare an oscilloscope (Tektronix was used in this demo) in triggered single mode

• While operating the system with the previous setting, increase the modulation index of the first module from 0.5 to 0.9

• Monitor the transient effect of the modulation index variation on the phase voltage, line-to-line voltage, and phase current of the power module using the oscilloscope

• Reduce the modulation index of the first power module to 0.8

• Reduce the switching frequency of the first module to 10 kHz

• Prepare the oscilloscope (Tektronix was used in this demo) in triggered single mode

• Increase the switching frequency of the first module from 10 kHz to 40 kHz

• Monitor the transient effect of the switching frequency variation on the phase voltage, line-to-line voltage, and phase current of the power module using the oscilloscope

• Prepare the oscilloscope (Tektronix was used in this demo) in triggered single mode

• While maintaining the same operational condition of the previous test, increase the reference frequency of the first power module from 60 Hz to 120 Hz.

• Monitor the transient effect of the reference frequency variation on the phase voltage, line-to-line voltage, and phase current of the power module using the oscilloscope

Shutdown Sequences

To shut down the test bench, the following sequences must be considered:

• Reduce the modulation index of both power modules to 0.1. This step helps to gradually discharge the capacitors through the loads.

• Disable or shut down the main DC power supply.

• Disable the PWM modulators

• Reset the model in RT-LAB

Demo File