Development of Large Capacity Programmable Harmonic Current Generator Based on Three-phase-four-wire Configuration

The large capacity harmonic current generator based on three-phase four-wire configuration uses four-leg converter as its main circuit. So it is different from the traditional small capacity linear current source. The whole equipment can output steady harmonic current include the selective order harmonic (below 25th order), reactive current and unbalanced current. Besides, dynamic change process of harmonic current can also be accurately simulated from the equipment. The output harmonic current can be set from communicating with computer or the EPROM. The harmonic current generator can be applied to testing electrical measure equipment or debugging the harmonic current elimination equipments. This paper first introduces the operation principle and main circuit; and then analyzes the control circuit structure and presents one control method with voltage feedforward control and the output current DFT feedback control; lastly the simulation results and the experiment results based on 50 kVA harmonic current generator are given in this paper. The results of the simulation and experiment verify well performance of the device even though for the large capacity