具有定位功能的SiC MOSFET宽温度范围高精度导通电压测量方法

Condition monitoring technology can significantly improve system reliability by monitoring the device degradation process in real-time and implementing predictive maintenance. on-state voltage is the most practical health monitoring indicator for SiC mosfets so far, and their online extraction technology is a challenge for current research. Existing converter-level on-state voltage measurement circuits cannot well maintain low error within a wide temperature range and cannot individually measure the on-state voltage of each semiconductor. To address these limitations, this article proposes a wide temperature range and high-accuracy converter-level on-state voltage measurement method with localization function for SiC mosfets. First, the operating principle and individually measured function of the proposed method in a single-phase inverter are illustrated. Then, the steady-state error ϵt and response time T of the proposed circuit are analyzed theoretically to prove the feasibility of the method. It is proved that the ϵt is independent of the input on-state voltage. Finally, a detailed comparison was made with existing circuits in terms of circuit performance and a prototype is built to prove the ability of the proposed method to individually measure each semiconductor. The circuit is verified to have higher accuracy (≈0.01%) over a wider temperature range (25 °C–100 °C) and fast dynamic response (≈450 ns).