A Synchronous Distributed Control and Communication Network for SiC-Based Scalable Impedance Measurement Unit

Modular single-phase impedance measurement unit (IMU) has been proven promising in power system stability study owing to the simplicity, scalability, and high control bandwidth. This paper further extends the modular design of IMU from power stage to control system. Distributed control system, the preferred control architecture for large-scale multi-node power electronics, has encountered challenges concerning tight synchronization while applied for SiC-MOSFET-based power converters. This paper investigates the influence of synchronization accuracy on harmonics under phase-shifted-carrier PWM, and proposes an effective approach to address the synchronization issue without control hardware revision. A synchronous distributed control and communication protocol with well-performed 25 ns accuracy and 16.7 μs control cycle is experimentally demonstrated on a 120 kHz SiC-based IMU.