Patent ID: 11899067
Assignee: SHANGHAI JIAO TONG UNIVERSITY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 8:
9. The testing system according to claim 7, wherein the capacitor voltage balancing module comprises an averaging element, a sign judgment element, an adder, a multiplier, and a PI controller, wherein the averaging element is connected to the sign judgment element through an output terminal of the adder, and the averaging element is connected in series with the PI controller after passing through the multiplier;
the capacitor voltage balancing module performs a closed-loop control strategy on the capacitor voltages of the plurality of tested SMs in the testing module group, and the closed-loop control strategy is as follows:
average values Vavg1 and Vavg2 of the capacitor voltages of the plurality of tested SMs in a testing arm of the plurality of testing arms are respectively compared with reference capacitor voltage signals Vref1 and Vref2 output by the cascaded converter system parameter model to obtain a capacitor voltage difference;
the capacitor voltage difference is multiplied by a polarity of a testing current signal output by the current generator, and then superimposed with voltage reference signals uref1 and uref2 output by the cascaded converter system parameter model after passing through the PI controller, as an input signal of the switching signal modulation module; an output signal of the capacitor voltage balancing module determines a number of inserted SMs in a next switching cycle;
the switching signal modulation module adopts a voltage modulation method to determine a gating signal of the each tested SM in the testing module group based on a preset carrier waveform and the target voltage signal generated by the capacitor voltage balancing module, or determine the gating signal of the each tested SM according to a sorting sequence of the capacitor voltages and the direction of the testing current signal, wherein the capacitor voltages of the plurality of tested SMs in the testing module group are identical to capacitor voltages of tested SMs in the actual cascaded converter.