单相电路谐波及无功电流实时检测的研究

Study on Real-time Detection of Harmonics and Reactive Currents in Single Phase Circuit

为了解决单相电路瞬时谐波及无功电流检测方法存在的不足,本文利用三角函数的有关特性,提出了一种新的单相电路谐波和无功电流实时检测方法,它通过计算得到基波有功和无功电流,进而得到谐波电流。其优点是:整个运算电路结构简单、成本低;既能单独检测出畸变电流中的任意电流分量,又能获得谐波和无功电流之和;谐波电流检测结果不受电网电压畸变的影响;引入无功及谐波电流作为反馈信号,补偿了低通滤波器的延时,加快了检测的动态响应速度。理论分析和仿真实验证实了该方法的有效性和可行性。

In order to meet the demand of detecting instantaneous harmonics and reactive currents in single phase circuit, a new method is proposed for real-time detection of harmonics and reactive currents in single phase circuit. By the use of the characteristics of triangle function, the fundamental active and reactive currents are obntained through calculation, finally the harmonics current is obtained. The advantages of this method are shown in the following aspects. Firstly, the whole circuit configuration is simple and low-cost; Secondly, it can detect not only the any current component in distorted current but also the sum of the harmonics and reactive currents; Thirdly, the outcome of the harmonics current is not affected by the distortion of the voltage; Finally, in order to compensate the delay of the low pass filter, the harmonics and reactive currents are used as feedback, so the speed of dynamic response is accelerated. The theoretical analysis and simulation illustrate the effectivity and performance of the proposed method.