An open-switch fault detection method and tolerance controls based on MPDPC in a NPC rectifier

In recent years, fault tolerance has become one of the most interesting topics because the open-switch faults rise to unbalance of the AC input currents and unable to control DC-link voltage that can cause serious damage to the connected application. This paper proposes a model predictive direct power control (MPDPC) method to tolerance control using a neutral point clamped (NPC) topology in a switch fault situation. This method uses the cost function concerning active power and reactive power to select a voltage vector and can detect the open-switch fault without using additional devices or complex calculations. Simulations are carried out to confirm the reliability of the proposed fault-detection method.