参数变化对抛物线PWM电流控制的影响及其对策

Impacts of Parameter Variations on Parabolic PWM Current Control and Its Solutions

抛物线脉宽调制电流控制方法具有优良的动静态特性,可广泛用于各种电压型功率变换器。但在其理论推导过程中,并没有考虑变换器串联电感内阻等参数的影响。通过理论分析,推导出电感内阻与该电流控制方法中的抛物线幅值之间的数学关系,证明变换器电感内阻对电流控制性能的影响很小,可以忽略不计。抛物线幅值直接与变换器串联电感及直流母线电压有关,为了消除这些参数变化对控制性能的影响,推导出抛物线幅值偏差与开关周期偏差及电流跟踪误差正负峰值偏差之间的数学关系,据此提出一种变换器参数变化的自适应补偿控制策略。仿真和实验验证了理论分析的正确性及上述控制策略的可行性和有效性。

The parabolic pulse-width modulation current control method has excellent static and dynamic characteristics and it can be used in a variety of voltage-source converters （VSC）. But in its theoretical derivation, the influence of the inductor equivalent series resistance （ESR） and other parameters in the converter were not considered. Through theoretical analysis, this paper derived the mathematical relationship between the ESR and the parabola amplitude involved in this proposed current control method, and proved that the ESR has little effect on the current control performance and it can be neglected. The parabola amplitude is directly related to the inductance and the DC link voltage of VSC. In order to eliminate the impact of these parameter variations on the control performance, an adaptive compensation control strategy was presented based on the derived mathematical relationships between the parabola amplitude deviation and the switching period deviation, and the deviation of the plus and minus current error peak. Both the simulation and experimental results verify not only the correctness of the theoretical analysis, but also the feasibility and effectiveness of the proposed control strategy.