Aprototypebrushless doubly-fed machine (BDFM) with a capacity of 5 kVA is used as the generator in the experimental platform. An 11 kW three-phase induction motor is connected to the BDFM coaxially as the prime motor, which is driven by an inverter with the rated power of 11 kW. The core components of the experimental platform is two PWM power converters: the control winding (CW) side converter and the power-supply side converter. Both power converters use IGBTs as switching devices, and the control of the two converters is achieved by two relatively independent control boards (CW side converter control board and power- supply side converter control board). The hardware configuration of the two control boards is completely consistent, except for the control algorithms. The CW side converter and the power-supply side converter are connected by the dc bus, which is connected with four thin film capacitors in parallel, with the capacitance of 4000 μF and rated voltage of 700 V per capacitor. Therefore, the total capacitance of the dc bus capacitors is 16000 μF. The pre-charged circuit of the experimental platform is used to charge the dc bus capacitors before starting the system, so that the CW side converter can operate normally during the start-up of the system to control the excitation current of the CW. The pre-charged circuit can be removed from the control system when the system startup is completed.

The platform can be used for variable-speed test of BDFM power generation system under various loads, and verify various new control methods for the BDFM system.