基于瞬时无功功率理论的改进谐波检测APF设计

The Design of a Improved Harmonic Detection Method APF Based on Instantaneous Reactive Power Theory

摘要: 由于电网中大量电力电子器件的应用，导致电网中谐波问题严重。解决电网谐波问题，首先是对电网中谐波成分的检测，将三相三线制的电力系统中瞬时无功理论的基本原理，推广到三相四线制系统，验证在存在零序电流的情况下，低压配电网系统对检测负载电流谐波含量的实用性。在检测谐波含量的过程中，为有效解决传统方法中跟踪精度和响应速度无法兼备的问题，利用引入电流平均值法模块来代替传统LPF模块。通过Matlab搭建仿真模型，分析优化后算法的适用性及其高效性能。证明改进后的方法可以有效的解决精度和响应速度之间的问题，更有效的完成对谐波电流的检测，从而计算出指令电流，以便于实现对电网电流的补偿。

Abstract: Due to the application of a large number of power electronic devices in the grid, the harmonics problem is serious. The first to solve the harmonics problem is detection of harmonic components in power grid. The basic principle of the instantaneous power system of three-phase-three-wire system in reactive power theory is extended to three-phase-four-wire system by examining the practicability for harmonic detection in low voltage distribution network system with zero sequence current. In the process, for solving a tradeoff between maladjustment and the speed of dynamic response in the conventional detection method, the low-pass filter is substituted by current average method. By using the platform of Matlab to prove its applicability and highly active ability, it aims to prove that the improved method can resolve problems between accuracy and response speed and be more efficient detection of current harmonics. Thus we can calculate the referential current to complete the compensation of grid current.