分布式发电系统并网公共连接点电压幅相检测方法

摘要

提出一种新型三相幅相检测方法,该方法基于PQR变换,实现了三相电压基波正序、负序分量解耦.电网电压的基波正序分量和负序分量分离后,基波正序分量及基波负序分量的幅值和相位可以分别被检测出来.仿真结果表明,在电网严重谐波畸变条件下,提出的新型三相幅相检测方法克服了传统三相软件锁相环路存在的问题,能准确地跟踪基波正序电压的幅值和相位,在同等检测精度下有效提高了动态响应速度,可应用于分布式发电系统并网公共连接点电压幅相检测.%It is a precondition of riding through the grid faults for distributed generation systems that the magnitude/phase information of connected-grid point of common coupling (PCC) must be exacted fleetly, so that the control subsystem of distributed generation systems could tackle the faults. The conventional three-phase software phase-locked loop ( SPLL) has a low speed of dynamic response affected by negative-sequence and harmonic components. Also it could not exactly extract the foundational positive-sequence magnitude/phase of three-phase voltages. A novel three-phase magnitude-phase detection method tased on PQR transformation is proposed. The proposed method could decouple the positive PQR and negative PQR sequences and detected the magnitudes/phases of foundational positive-sequence component and negative-sequence component of three-phase voltages. The simulation results verify that the proposed method overcomes the shortcoming of conventional three-phase SPLL; under bad harmonic condition, the proposed method can track the magnitude/phase information of the foundational positive-sequence voltage accurately and improve the speed of dynamic response effectively under equivalent detection accuracy condition; the proposed method can be applied in the voltage magnitude-phase detection for the connected-grid PCC of distributed generation systems.