CAJ | 학술논문

针对三电平中点钳位( neutral point clamped, NPC)变流器中点电压波动问题,分析了三电平变流器基本工作原理,提出了一种适用于任意调制策略的三电平变流器中点电压平衡策略。该策略以输出线电压满足要求为控制目标,根据中点电压的波动情况实时修正调制策略的输出开关状态。鉴于单开关周期完全可控区域的重要意义,本文分别分析了调制策略为正弦脉宽调制( si-nusoidal pulse width modulation,SPWM)策略和空间矢量脉宽调制( space vector pulse width modula-tion,SVPWM)策略时新型中点电压平衡策略的单开关周期完全可控区域。理论分析和仿真结果表明,新型中点电压平衡策略具有普遍适用、实现简单的优点,其单开关周期完全可控区域受调制策略、调制度、运行时间和功率因数的影响。
침대삼전평중점겸위( neutral point clamped, NPC)변류기중점전압파동문제,분석료삼전평변류기기본공작원리,제출료일충괄용우임의조제책략적삼전평변류기중점전압평형책략。해책략이수출선전압만족요구위공제목표,근거중점전압적파동정황실시수정조제책략적수출개관상태。감우단개관주기완전가공구역적중요의의,본문분별분석료조제책략위정현맥관조제( si-nusoidal pulse width modulation,SPWM)책략화공간시량맥관조제( space vector pulse width modula-tion,SVPWM)책략시신형중점전압평형책략적단개관주기완전가공구역。이론분석화방진결과표명,신형중점전압평형책략구유보편괄용、실현간단적우점,기단개관주기완전가공구역수조제책략、조제도、운행시간화공솔인수적영향。
A novel neutral point ( NP ) voltage control strategy of three - level neutral point clamped ( NPC) converter was proposed to eliminate the NP voltage fluctuation under any modulation strategy. The novel NP voltage control strategy was based on the control target of output line voltage, and real-time correction of output switching states were given according to the NP voltage fluctuation. It is suitable for any modulation strategy as it only deals with the output switching states of any modulation strategy. In order to analyze the control effect of the proposed strategy, the single switch cycle control region was taken as the measurement standard and analysis of fully control region was conducted respectively when using the two most commonly used modulation strategy, sinusoidal pulse width modulation ( SPWM) strategy and space vector pulse width modulation ( SVPWM) . The theoretical analysis and simulation results show that the novel NP voltage control strategy has the advantages of wide application and easy implementation. Whereas, the fully control region of the new strategy is affected by modulation strategy, modulation index and power factor.