基于温度的MMC变流器均压控制方法

Voltage sharing control method of MMC converter valve based on temperature

为了提高MMC变流器的可靠性,在传统均压控制的基础上引入了热平衡控制,通过控制子模块的投切过程以减少子模块温度波动,实现MMC变流器可靠性的改善。针对子模块温度的估算,提出了以IGBT模块的福斯特热网络模型为基础的子模块温度计算方法,在电压均衡和热平衡控制过程中选择需要投切的子模块,通过减少不必要的子模块投切动作以降低子模块温度。采用Matlab/Simulink仿真平台对该控制方法进行验证,并将其验证结果与传统均压控制的温度波动和均压效果进行比较分析。结果表明该控制方法可有效降低器件温度波动,提高变流器的可靠性,具有较好的实用性。

To improve the reliability of the MMC converter, the heat balance control is introduced on the basis of the traditional mean voltage control. By controlling the switching process of the sub module to reduce the temperature fluctuation of the sub module, the reliability of the MMC converter is improved. To estimate the temperature of the sub module, the temperature calculation method based on the Forster thermal network model of the IGBT module is proposed. In the process of voltage balance and heat balance control, it selects the submodules that need to change the state. The sub module temperature can be reduced by reducing the unnecessary submodule switching action. The control method is validated by using Matlab/Simulink simulation platform, and the results of the test are compared with the temperature fluctuation and the uniform pressure effect of the traditional pressure control. The results show that the control method can effectively reduce the temperature fluctuation of the device and improve the reliability of the converter, and has good practicability.