An Extended DPWM Strategy With Unconditional Balanced Neutral Point Voltage for Neutral Point Clamped Three-Level Converter
An Extended DPWM Strategy With Unconditional Balanced Neutral Point Voltage for Neutral Point Clamped Three-Level Converter
复制标题
DOI：
10.1109/tie.2018.2885735
复制
发表时间：
2019-11
影响因子：
7.7
通讯作者：
Kewei Chen;Weidong Jiang;Peixia Wang
中科院分区：
文献类型：
--
作者：
Kewei Chen;Weidong Jiang;Peixia Wang
根据箝位方式的不同，揭示了中点箝位三电平变换器传统不连续脉宽调制（DPWM）的9种工作模式（C_MODE1-9）。针对传统的DPWM不能在调制指数（MI）和功率因数（PF）的全范围内平衡中性点（NP）电压的问题，提出了两种扩展模式（EMODES）来平衡NP电压。扩展的不连续脉宽调制（EDPWM）的特点是交替使用C_MODE和E_MODE，因此EDPWM可以在MI和PF的整个范围内平衡NP电压，并且在一个开关周期内C_MODE和E_MODE的开关次数分别为2次和3次，因此EDPWM的开关损耗低于其他脉宽调制（PWM）策略。从开关损耗、波形质量和NP电压控制能力等方面分析了EDPWM的性能，并与传统DPWM、空间矢量PWM（SVPWM）和虚拟SVPWM（VSVPWM）进行了比较。最后通过实验验证了该方法的可行性和优越性。
According to different clamping methods, nine modes (C_MODE1-9) of the traditional discontinuous pulsewidth modulation (DPWM) for neutral-point-clamped three-level converter have been revealed. Since traditional DPWM cannot balance neutral point (NP) voltage under the full range of modulation index (MI) and power factor (PF), two extended modes (E _MODEs) are proposed in this paper, which can balance NP voltage. The proposed extended discontinuous pulsewidth modulation (EDPWM) is characterized by using C_MODEs and E_MODEs alternately.Therefore, EDPWM can balance NP voltage under the full range of MI and PF. Since the switching numbers under C_MODE and E_MODE in one switching cycle are two and three, respectively, the switching loss under EDPWM is lower than that under other pulsewidth modulation (PWM) strategies. The performance of EDPWM is analyzed and compared with traditional DPWM, space vector PWM (SVPWM) and virtual SVPWM (VSVPWM) in terms of switching loss, waveform quality, and the ability of NP voltage control. Finally, the feasibility and superiority of the proposed method are verified by experiments.