Research And Design Of Three Phases Three Wires Low Voltage SVG Controller

In the field of low-voltage power supply, nonlinear increase of electrical load and power electronic equipment widely used in the power to reactive power and harmonic pollution massive existence. To the power grid brought serious extra burden and the serious influence power quality. At the same time, more and more electrical equipment to the electric power quality requirements have increased, the reactive power compensation generator with the historical trend is developed. Static reactive power generator with a special circuit structure, high frequency power electronic switching device, advanced control algorithm with real-time, the precise reactive compensation ability, and has the filter and inhibit the harmonic function. It is because of these incomparable advantage, make it become the important means of reactive power compensation and the main direction of future development.In recent years, with static reactive power generator circuit structure, the real-time signal detection, algorithm control areas to improve, make its appear various control mode. In this paper the design phase of the circuit to mainly converter static reactive power generator theoretical basis is mature, the key is the development and design of the device efficiency. First of all in the further understanding of static reactive power generator based on the basic principle, choose suitable for low voltage reactive compensation to switch frequency and high and system capacity of the characteristics of the limited control strategy-based on instantaneous reactive power theory of direct current control. And detailed discussion based on instantaneous reactive power theory IP-IQ test reactive current. Controller interface card using DSP + FPGA architecture, the ascent of the performance of the controller, make its have real-time and accurate reactive compensation ability. Phase detection and tracking the use of advanced single phase locked loop algorithm, and may, according to the state of the plant operation send automatic synchronizing signal, for device display fine performance to lay the solid foundation.Research on the structure and control strategy and proposes the engineering of the most widely used type of three-phase VSI SVG structure parameter and direct current control scheme. This method through the dq transformation to realize active current and reactive current in the dq decoupling control of the plane. Based on instantaneous reactive power theory Ip-Iq electric current detection algorithm was proposed to detect the load current base wave and the harmonic reactive size, at the same time, the outer ring of the output voltage is coupled to the active loop electric circuit.and the outer ring and realize the voltage instantaneous electric circuit.and the double loop control. Application is the way the triangle wave PWM pulse width modulation method for the six IGBT drive signal. In MATLAB to 380 V / + 200 kvar VSI three-phase main circuit parameters, type SVG Ip-Iq electric current detection algorithm and the direct current control strategies of simulation test system. The simulation results show that this control schemes have good SVG dynamic response characteristics and static compensation effect, verify the main circuit and control mode of correctness, advantages and high efficiency.