Research On Control Method For Shunt Active Power Filter

Nowdays, the development of power electronic devices and a lot of fast power electronics technology is widely used in metallurgy, steel and chemical sectors, which leads that the harmonic pollution is worsening. The harmonic electrical equipment results in great harm to the power system. Active Power Filter(APF) is the means of power electronics technology, improved the power quality of the system greatly.This paper analyzes the topology of the three-phase shunt active power filter converter, and builts its equivalent single-phase model, which deduces mathematical model. By studying the mathematical expressions, you can understand the converter of the energy flows in DC side and AC side easily, which facilitates the control system design. This paper studies several common harmonic current detection algorithms firstly, and detailly analyzes based on instantaneous reactive power theory ip-iq harmonic detection method. By simulation studies, the algorithm is used in the experimental device harmonic current detection algorithm. The advantage of ip-iq harmonic detection method is able to form a very intuitive flow of electricity to define instantaneous reactive power, which provides a very convenient way for the active power filter. This paper also studied two important structures in harmonic current detection algorithm of a digital phase-locked loop and a low-pass digital filter design, and gives the implementation process.In order to achieve the purpose of active power filter output current tracking command current, the paper analyzes the two common compensation current tracking control method, and gives their advantages and disadvantages. While studying of the current control method, the SVPWM control method is implemented in the experimental device, and has been implemented on an experimental prototype. Besides, this article designed APF double closed loop control system, which can well complete the command current tracking control, and has been verified in simulation and experiment.This paper studies the impact of Active Power Filter DC voltage compensation system performance, and analyzes the conventional PI control methods. Because the conventional PI control is not satisfactory, we propose to be the fuzzy self adaptation PI control method. By the MATLAB simulation, the results is verified of the fuzzy self adaptive PI control with good steady and dynamic characteristics, significantly reduced the DC voltage fluctuation, with good control effect.Finally, this paper introduces the design of active power filter experimental device, and analyzes the APF main circuit and control system. Through the theoretical research above, the paper designed a capacity of 40 k VA shunt active power filter. Through the experiment of APF for harmonic detection, space vector PWM modulation and reactive power compensation, successfully verified the feasibility and validity of the proposed control method.