Research On 10kV Static Var Compensator

There is inadequate in the capacity of reactive power compensation and unreasonale of equipment, especially inadequate in the adjustable reactive power capacity and less in the rapid response of reactive power condition in China's Power Grid. Impact load will make grid reactive power imbalance and this will lead to the great fluctuations and flicker of grid voltage, more seriously to the damage to electrical equipment, voltage collapse and the destruction of the grid stability.FC+TCR type SVC, which has fast response, can dynamically compensate system reactive power, improve system power factor, suppress system voltage fluctuation and flicker. So it has been widely used for reactive power compensation in electric railways, electric arc furnace, rolling mill, etc., but less in small and medium-sized customers due to its high costs. It is necessary to develop a FC+TCR type SVC for small and medium users because of their great reactive power compensation capacity and needs. For this purpose, one 10kV FC+TCR type SVC was developed and some research and design studies are followed.According to the changes of loads reactive power, the main circuit parameters of the SVC were calculated; thyristor trigger plates with self-snubbing energy circuit and BOD over-voltage protection boards were designed. Choose an embedded control panel, TMS320F2812 as its core component, design signals access circuit and thyristor trigger pulses forming circuit to constitute the most basic SVC controller.Based on instantaneous reactive power compensation theory and the principle of balancing the unbalanced load (Steinmetz Principle), the model of SVC which calculated electric Napes, was established. In this model, the instantaneous values of voltages and currents were sampled to calculate reactive power and Napes needed to compensate, and thyristor control angles were obtained though look-up table method which was used in SVC prototype. Simulation and experimental results show that the algorithm is fast, efficient and accurate, the main circuit parameters are reasonable, with practical engineering application values.