Level-Switching Control Strategy for Reinjection Multilevel Current-Source Rectifiers

When the device is running, the device is prone to failure due to various reasons such as environmental factors, which affects the normal operation. When the injection multilevel current source rectifier is running, the injection branch on the DC side is faulty, resulting in a change in the number of injection branches. Because the branch currents are not equal, the injection branch loses the ability to eliminate harmonics and damages its normal operating characteristics. Analyzes the fault characteristics in the injection branch and identifies the main causes for low-order current harmonics generated on the grid side. A level smooth switching control strategy based on RMCSC is presented. The working principle of the strategy is analyzed in detail, and the logical reasoning principle is given. And more enough to keep the output current and power stability to maintain the branch's current balance. Finally, PSCAD simulation is conducted to verify the effectiveness and rationality of this level-switching control strategy.