Active Power Filter And Its Application In Distribution Network

Active Power Filter is recognized as the most effective measure for harmonic control, reactive power compensation and the power quality improvement, and has become a hot spot in the power electronics application. In this paper, a more systematic and in-depth theoretical and application is researched for the parallel active power filter. Combining the advantages of Active Power Filter and Passive Power Filter, Improved Simulated Annealing-Particle Swarm Optimization algorithm is adopted to optimize the allocation of two filtering device, laid a good foundation for its utility in the power distribution network.Accurately and real-time detect transient changed distorted current in power grid, provide reference signal for precise compensation of Active Power Filter control system is a key of compensation performance quality.This article proposes an improved harmonic current detection method depend on summarizing the variety of harmonic detection methods, discusses its basic principle, and furthermore process the simulate conformation. This method leave out the way in three-phase to two-phase coordinate transformation and inverter change,so the calculated amount is little, and it be appropriate for the situation that there exist certain distortion in the grid voltage, as well as be able to test out the current component for compensation and has good dynamic performance and high precision.As a result of choosing different control methods are about to directly influence system response speed and harmonic treatment effect, and that Active Power Filter system model is a multiple input,multiple output,coupled nonlinear system.This article established dq coordinates Active Power Filter mathematical model based on adaptive control principle, feedback linearization technique and input/output power balance characteristics,as well as proposes a new adaptive nonlinear control method.Besides design the parameters of adaptive companies link, get power instantaneous active reference current and system state equation to realize the harmonic current tracking precisly in the circuitry and nonlinear load under unknown time-variance parameter e,even dispense with real-time detection and calculating load reactive current composition,so as to guarantee the stability of the dc side voltage and reduced the capacitor capacity.This control method compare with repeat predictive control and compound control,respectively,and through the simulation results prove that the proposed new adaptive nonlinear control method gives consideration to unity of dynamic performance and control precision, it is extremely applicable to Active Power Filter control, as well as completely satisfy the harmonic treatment application requests in distribution network.Due to the Passive Power Filter simple structure and low cost and could filters out specific order harmonic, Active Power Filter has good dynamic compensation properties. The Improved Simulated Annealing-Particle Swarm Optimization algorithm algorithm was adopted to optimize the configuration of two filter devices. That is, when the power structure, parameters and harmonic current are known, and the harmonic current to meet the constraints of the premise, have optimization calculations for the installation of the filter location, installation type, install group number and capacity optimization parameters. To ensure the harmonic ratio, total harmonic distortion of the each node in the network within the prescribed limits and under the premise of filtering devices safe and reliable operation, the power current total harmonic distortion and the investment cost of filtering devices in the whole network are minimum.