H桥级联三相大功率逆变器SVM优化控制策略

Optimization SVM Control Strategy for H-bridge Three Phase High Power Cascaded Inverter

传统空间矢量调制（spacevectormodulation，SVM）算法需要进行矢量判断、冗余选择等复杂运算，当输出电平数较高时，导致控制算法异常复杂而难以实现。为降低多电平SVM算法复杂度，提出一种基于SVM思想的级联型多电平逆变器优化控制策略，利用当级联级数增多时空间矢量密度也增大的特点，获得大幅度简化、具有较小控制误差的新型多电平空间矢量调制控制策略。该算法在较低的开关频率下，相比三角载波移相控制算法，可以得到电压谐波总畸变率（totalharmonicvoltagedistortion，THDu）较低的输出电压波形。理论分析和实验研究均证明了所提新型H桥级联多电平SVM控制策略的有效性和可行性。该控制算法已成功应用于某型级联高压逆变器产品中。

The traditional space vector modulation algorithm is difficult to be implemented when the output level of inverter increases because of the calculations for vectors judgment and redundancy vectors selection. In order to reduce the complexity of multilevel space vector modulation （SVM） algorithm, an optimal control strategy based on SVM for cascaded multi-level inverters was proposed in this paper which utilize the characteristics of the space vector density increase when the cascade series increase, and obtain a new type of multi-level SVM control strategy with small control error, and greatly simplified the control algorithm. Under the lower switching frequency, the proposed algorithm can get the lower output voltage waveform of total harmonic voltage distortion （THDu） compared with the triangular carrier phase shift control algorithm. Theoretical analysis and experimental results prove its validity and feasibility. The novel H-bridge cascade multi-level SVM control strategy has been successfully applied to a cascade high-voltage inverter products.