Research On Hybrid Reactive Power Compensation Switch Based On DSP

In the field of low and medium voltage reactive power compensation,parallel capacitor banks switching based on phase-controlled switching technology is a better way than others.However,the accuracy and reliability of contacts switching point are the key factors affecting the efficiency.It is technically difficult to meet all the requirements.In recent years,ABB has proposed a phase-controlled model composed of semiconductor and mechanical switches.Its essence is to match the mechanical switch and characteristics of the semiconductor such as unidirectional conductivity,so that the capacitor banks are put into the transmission line when the semiconductor is natural turned on or the capacitor banks are cut off when the semiconductor is natural turned off.Thereby it can suppress the transient phenomenon such as surges,to achieve the purpose of reactive power compensation with free transient.Compared with the traditional phase-controlled switching technology,the new scheme will help the switch work in a relative wide phase range.It also has more tolerance to the dispersion of the operating mechanism,and more benefit to the realization of the flexible phase-controlled switching technology.Firstly,the paper shows a brief introduction and analysis of the working principle and switching strategy based on the ABB model,and presents an improved model of Y-connection hybrid switching capacitor banks system of vacuum switch and power electronic device,the model is used for reactive power compensation and splitting short circuit faults.And it proposes a set of corresponding switching strategy for switching three-phase capacitor banks and introduces the three-phase high-speed switch applied in the experiment.Then,a 10kV-transmission line model is established based on Matlab software in this paper.Compared with other methods,the model reaches the conclusion that the hybrid reactive power compensation method can suppress the transient phenomenon more effectively in the simulation.Also it proves the advantage of a larger ideal phase angle when switching capacitor banks.Compared with the original model and traditional phase-controlled switching technology,it summarizes that the improved model has many advantages such as having a wide range of ideal operating phase range and applications.According to the analysis of theory and simulation verification of the hybrid reactive power compensation switch model,this paper designs a set of synchronous control device based on DSP.It mainly includes control circuit based on DSP and peripheral circuits such as sampling signal circuit to ensure the reliable implement of hybrid reactive power compensation strategy.Finally,the experimental platform is built,and the paper analyzes the dispersion of the three-phase high-speed switch.Compared with inputting the Y-connection three-phase capacitor banks randomly,both the experimental waveform and the data verify the effectiveness of suppressing transient phenomenon in hybrid inputting experiment.