三相抛物线PWM电流控制解耦方法(方法I)

Three-phase Parabolic PWM Current Control Decoupling Method (Method I)

抛物线脉宽调制(pulse width modulation,PWM)电流控制方法具有与传统滞环控制相媲美的高精度、快速电流跟踪控制性能,并能保持开关频率基本恒定,可广泛用于各种电压型功率变换器。但是现有文献仅给出了单相抛物线PWM电流控制方案,并未涉及如何用于三相三线变换器。该文利用叠加原理,将三相三线系统等效为虚构的三相四线系统与虚构的零序系统之和,提出一种三相抛物线PWM电流控制解耦方法,该方法通过3个独立的单相抛物线PWM电流控制器对虚构的三相电流进行控制,间接实现三相三线变换器实际电流的高精度快速跟踪控制。仿真和实验结果验证了该解耦控制方法的可行性和有效性。

Compared with the traditional hysteresis control, the parabolic pulse width modulation （PWM） current control technique features a reasonably fast response, outstanding performance of average current tracking as well as an almost constant switching frequency, and could be widely used in a variety of voltage source converters （VSC）. However, only the single-phase parabolic PWM current control （PCC） scheme was presented in the published literatures, and how to be used in the three-phase three-wire VSCs was not involved. In this paper, a three-phase PCC decoupling scheme was proposed by converting the three-phase three-wire system into a virtual three-phase four-wire system and a virtual zero-sequence system based on the superposition principle. With this scheme, three independent parabolic current controllers were used to control the virtual three-phase currents, and indirectly control the actual currents of the three-phase three-wire VSC with high-performance. Both simulation and experimental results verify validity and correctness of the proposed three-phase PCC decoupling scheme.