一种参数自适应增强型单相锁相环的研究与应用

Research and Application of a Parameter Adaptive Enhanced Single-phase Phase-locked Loop

在铁路牵引供电系统中,电压存在频率/相位突变、幅值波动、谐波污染等网压畸变问题。传统单相锁相环在动态响应速度及应对这类异常网压工况方面存在不足,无法满足机车、动车四象限变流器的实时控制要求。为此,文章提出了一种参数自适应增强型锁相环的方法,其引用自适应控制策略,使增益系数自适应变化,改善了因相位跳变而导致的频率瞬间扰动问题。相较于传统锁相环,参数自适应增强型锁相环对异常电网环境适应性强,具有快速准确捕获电网信息的良好动态性能,且锁相至少可以提前2~3个电网周期。仿真和实验结果验证了该锁相环方法的有效性和可行性。

In a railway traction power supply system,there are problems of network voltage distortion such as frequency/phase mutation,amplitude drop,harmonic pollution and so on.Traditional single-phase PLL has shortcomings in dynamic response speed and response to such abnormal network conditions.It is unable to meet the real-time control requirements of four-quadrant converter for locomotive and EMU.Therefore,a parameter-adaptive enhanced phase-locked loop method is proposed in this paper.This method uses an adaptive control strategy to adaptively adjust the gain coefficient to improve the frequency transient disturbance caused by phase jumps.Compared with the traditional phase-locked loop,it has good adaptability to abnormal power grid environment,and has a good dynamic performance in capturing the phase of the grid quickly and accurately.Finally,the validity and feasibility of the new phase-locked loop method are verified by simulation and experiment.