Research and design on multi-target current tracking control strategy of cascaded H-bridge static var generator

This paper describes an improved current tracking control strategy about cascaded H-bridge static var generator (SVG). This control strategy can not only increase dynamic response speed and power quality but also enhance the reliability of the grid. The working principle of the reactive power compensation is analyzed, then mathematic model of the cascaded H-bridge SVG is established, the model is discrete to be a discrete mathematic model. The discrete-time static observer is constructed and an improved dead-beat current control strategy is proposed. By comparing the dead-beat control and the current feed-forward coupling control, this dead-beat control has multitarget advantage. And by testing on a 10-KV 2-Mvar reactive power compensation system, the advantage of the dead-beat current tracking control is tested. Simulation and experimental results show that this control strategy can improve the dynamic performance and sine degree of the waveforms.