Modelling and Analysis of High-Speed Flywheel Energy Storage Control System and PLC Implementation

This paper introduces a flywheel energy storage system (FESS) with programmable logic controller (PLC). The FESS uses a high-speed permanent magnet synchronous machine (PMSM), which adopts field-oriented control (FOC) with PI control units. The PLC and its connection with an OPC unified architecture (OPC-UA) composite an industrial Internet-of-Things (IoT) system. The cooperation among the drive system's controller, the PLC, and auxiliary devices is essential for the system control. This paper focuses on analyzing the system character of the FESS by transfer function analysis. It also introduces the whole PLC system and defines reasonable measurement and communication units. First, we built a PMSM mathematical model, then, the PI control and its tuning methods are introduced. Through system simplifying, the FESS is modelled by a transfer function. The motor parameters are evaluated by experiments. The simulation shows that the PI parameters change the system response speed. This should be considered in the design phase for the communication system. In the end, the system implementation in a PLC environment in a DC-microgrid lab is demonstrated.