In this section, the results of tests performed on the TIDM-02017 inverter system are presented. To test the traction inverter, the inverter was connected to a 48-V, 5.5-kW interior PMSM motor. The motor was mounted on a hysteresis dynamometer which generates mechanical load on the motor shaft. The control of the inverter, as mentioned previously, runs in torque mode. Therefore, the inverter generates the commanded torque and the speed of the motor is determined by the applied external load. This mode of testing mimics real-world operating scenarios for traction motor drives. For this test, the dynamometer operates in constant speed mode. In other words, the dynamometer generates the necessary load to regulate the speed of the motor to the set speed reference. Table 4-3 shows the results of the motor-dynamometer testing of the inverter for different reference speeds and torque (current) references. The motor shaft power measured by the dynamometer and input power measured by the DC source are also given. The test conditions and obtained power results are shown in Table 4-3. The test waveforms for the phase current and the DC bus voltage are shown in Figure 4-6, Figure 4-7, Figure 4-8, and Figure 4-9.

Figure 4-6 DC Bus Voltage and Phase Current Waveforms at Motor Speed = 2000 rpm, Current Reference = 55 A

Figure 4-7 DC Bus Voltage and Phase Current Waveforms at Motor Speed = 2500 rpm, Current Reference = 55 A

Figure 4-8 DC Bus Voltage and Phase Current Waveforms at Motor Speed = 3000 rpm, Current Reference = 95 A

Figure 4-9 DC Bus Voltage and Phase Current Waveforms at Motor Speed = 3500 rpm, Current Reference = 160 A