In this paper, space opposite vectors modulation (SOVM) is proposed to decrease common-mode voltage (CMV), and also improve inverter switching losses compared to pulsewidth modulation 7 (PWM7) for dual two-level inverters (DTLI). Employing the control simplicity of DTLI to achieve multilevel winding voltages, the two conventional two-level inverters of DTLI are independently controlled; consequently, the capability of adjusting phase difference between the carriers (PDC) of two inverters is established. To mathematically evaluate and compare the performance of DTLI driven by SOVM and PWM7, CMV and losses for different PWMs are formulated. Moreover, contour, three- and two-dimensional analyses are conducted to investigate the effects of PDC and modulation index on CMV, voltage total harmonic distortion (THD), voltage weighted THD and switching losses. All theoretical bases, simulation results from MATLAB/Simulink and experimental results conducted by a DTLI prototype validate the superiority of SOVM over PWM7.

中文翻译：

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隔离直流源双两电平逆变器中空间相反矢量调制的介绍及优点


在本文中，提出了空间相反矢量调制（SOVM）来降低共模电压（CMV），并且与双两电平逆变器（DTLI）的脉宽调制7（PWM7）相比，还可以改善逆变器开关损耗。利用DTLI的控制简单性来实现多电平绕组电压，DTLI的两个传统两电平逆变器是独立控制的；由此，建立了调节两个逆变器的载波（PDC）之间的相位差的能力。为了从数学上评估和比较由 SOVM 和 PWM7 驱动的 DTLI 的性能，制定了不同 PWM 的 CMV 和损耗。此外，还进行了轮廓、三维和二维分析，以研究 PDC 和调制指数对 CMV、电压总谐波失真 (THD)、电压加权 THD 和开关损耗的影响。所有的理论基础、MATLAB/Simulink 的仿真结果以及 DTLI 原型进行的实验结果都验证了 SOVM 相对于 PWM7 的优越性。