Research on life prediction control of MMC submodule based on fiber sensing

Abstract

With the rapid development of energy, power electronic equipment plays a crucial role in renewable energy. Modular multilevel converter (MMC) has turned into cutting-edge inverter topology in flexible HVDC and offshore wind power situations. However, under the conditions of high humidity and high voltage, the internal submodules lifetime of MMC might be affected. The system reliability mainly depends on good running of the submodules, so stable performance of the submodules serious threat to the normal operation of the inverter. Therefore, this paper proposes a model based on Peck accelerated life predictable model, and model predictive control (MPC) strategy is improved, at the same time without affecting the external characteristics can better control the submodule voltage fluctuations. What is more, real time monitoring of the working environment of the converter through the optical fiber sensing module. Finally, the experimental and simulative outcomes show that the proposed control strategy can effectively reduce the voltage fluctuations in the small module, and the life parameters of the submodules can be obtained in real time by bringing the results into the proposed life prediction model. By comparing the results, the results can be obtained the proposed control strategy can effectively increase the reliability of the submodule.