级联H桥变换器主动热控制下的谐波性能优化

Harmonic performance optimization for cascaded H-bridge converter under active thermal control

针对级联H桥变换器主动热控制下不平衡运行时,钳位H桥模块在两倍载波频率附近产生大量谐波的问题,提出了一种级联H桥变换器主动热控制下的谐波性能优化策略。深入分析了变换器中钳位H桥模块热控制下输出电压的谐波失真,设计了基于H桥模块载波角来修正非常规PSPWM以消除了两倍载波频率边带谐波。利用级联H桥变换器样机开展了实验,测试结果为,采用谐波性能优化控制后,两倍载波频率附近主导谐波被消除,同时钳位H桥模块温度降低0.9℃。测试结果表明,主动热控制下的新型谐波性能优化策略可有效提高级联H桥变换器系统输出谐波性能,并实现H桥模块热均衡。

When the cascaded H-bridge converter operates unbalanced under active thermal control,the clamping H-bridge module generates a large number of harmonics around twice the carrier frequency.Aiming at this problem,a harmonic performance optimization strategy under active thermal control of the cascaded H-bridge converter is proposed.The harmonic distortion of the converter output voltage with the clamped H-bridge module under thermal control is analyzed in-depth,and an unconventional PSPWM based on the carrier angles correction of the H-bridge module is designed to eliminate the sideband harmonics of the double carrier frequency.Experiments were carried out using a prototype of the cascaded H-bridge converter,and the test result is that after adopting the harmonic performance optimization control,the dominant harmonics around twice the carrier frequency were eliminated,and the temperature of the clamping H-bridge module was reduced by 0.9℃.The test results show that the novel harmonic performance optimization strategy under the active thermal control can effectively improve the output harmonic performance of the cascaded H-bridge converter system and realize the thermal equilibrium of the H-bridge modules.