Simulation On Detection And Control Strategy For Active Power Filter And Application

With the rapid development of modern power electronics technology and continuous improvement,the way of power conversion gradually increased;At the same time,a large number of power electronic devices and nonlinear loads widely used lead to harmonic currents,which has a serious impact on the power quality of electricity grid.Active Power Filter(APF)improved power quality is a new power automation devices,which can be used to suppress dynamically network harmonics,compensate reactive power and improve the power factor of power system;Its applications has become a hot field in the electronics technology.The paper first briefly summarizes the causes of harmonic and hazards and related measures about harmonic suppression in the power system;And then it introduces the development status at home and abroad concerning APF,working principle,typical topology structure,the method of gaining harmonics and tracking instruction current dynamically and voltage control;The way of detecting harmonic current in this paper is based on instantaneous reactive power theory and instantaneous voltage vector orientation and the fundamental positive sequence voltage orientation of new method of extracting algorithm for instruction current is proposed.Finally,the simulation results show that the design of digital low pass filter and two methods of acquiring harmonic current are feasible and correct.When detection method and the topology of main circuit determined,tracking algorithm for command current determine the ability of harmonic management of the APF.According to the characteristics of the output current of grid-connected inverter device and the practical needs for control system,the paper takes the instantaneous current of direct control with harmonic elimination as control strategy.DC voltage adopts traditional PI controller and APF uses soft start controller as startup mode.Compared with the traditional method,the simulation shows that the algorithm is easy to implement and has high-precision with the fast response speed.Selecting high-performance digital signal processor TMS320F2811 as the core controller,controller is introduced including peripheral hardware circuit and software design scheme;The main circuit parameter of key components is determined by adopting the combination of simulation and engineering practical formula.Finally,a set of active power filter prototype is developed in this paper;the experimental analysis verifies the validity and feasibility of the above method.