双闭环正交相量锁相法的电网频率跟踪技术

GRID FREQUENCY TRACKING TECHNOLOGY OF DOUBLE CLOSED-LOOP ORTHOGONAL VECTOR LOCK STRATEGY

在分析传统基于旋转坐标变换单相锁相环(single-phase locked loop,SPLL)原理的基础上,针对单相瞬时无功锁相法的正交相量模块,提出一种基于双闭环结构的正交相量的产生方法和瞬时无功锁相技术,对比分析二阶通用积分器构建正交相量的方法和基于双闭环产生正交向量方法的数学特性。通过仿真证明,基于两种不同正交向量产生方法的锁相锁频技术,基于双闭环结构的正交相量的瞬时无功锁频锁相技术能较好地解决电网电压幅值变化、电网电压相位变化、电网电压频率变化、电网电压含有谐波时对锁相的影响,该新型锁相法能够很好的跟踪电网频率,保证逆变器的稳定性。

Aiming at orthogonal vector module of single phase instantaneous reactive lock method, the generation method of orthogonal forward according to transformation. The o vector and instantaneous reactive lock technique based on double closed-loop structure were put analyzing the traditional single phase locked loop （SPLL） principle based on rotating coordinate rthogonal property of produced orthogonal vector method constructed by the second-grade general integrator and the mathematical vector method based on double closed-loop were compared and analyzed. The simulation shows that the influence of the amplitude change, the phase change of grid voltage and the frequency change of grid voltage, as well as containing harmonic in grid voltage on phase lock can be better solved based on lock phase and lock frequency technology of generation method for two different orthogonal vectors and based on the instantaneous reactive lock frequency and phase lock technology of orthogonal vector of double close-loop structure. The new phase-locked method can well track grid frequency, guarantee the stability of the inverter.