无差拍控制的PWM变换器电压矢量序列优化

Voltage Vector Sequence Optimization in Dead-beat Control of PWM Converter

为了降低PWM变换器有功功率和无功功率的稳态误差,减小其交流侧输出正弦电流的谐波含量,建立了PWM变换器的无差拍预测直接功率控制系统的功率变化模型,给出了基于变换器交流侧电压角度位置划分扇区的电压矢量序列方法,由于扇区的分法与传统方法错开了一定的角度,避免了偶数扇区中出现所选的3个电压矢量对有功功率变化率或无功功率变化率的影响趋势相同的情况,也避免了辅矢量作用时间不合理的现象。快速调节功率的同时,减小了功率稳态误差,降低了电流谐波含量,使开关频率固定,且无需坐标变换和空间电压矢量调制。

In order to reduce steady state errors of active and reactive powers in PWM converter and harmonic content of the AC side output currents,the power changing models of dead-beat predictive direct power control system of PWM converter were put forward.The voltage vector sequence method based on angular location of the converter AC side voltage was proposed.As angular deviation of the proposed method and the traditional ones in division sector,the same tendency of active or reactive powers change rate via selected three voltage vectors in even sectors was avoided and the phenomena of unreasonable duration time of auxiliary vector was removed.The proposed dead-beat predictive direct power control method has many advantages of rapid power adjustment,decreasing steady state errors of powers,reducing harmonic content of currents,fixing switching frequency,no coordinate transformation and space vector modulation,et al.