Boost and flux-weakening control of engine direct connection type ipmsg over wide-speed range

This paper proposes a boost and flux-weakening control (BFWC) of engine direct connection type interior permanent magnet synchronous generator (IPMSG) over wide-speed range. Since the speed and the load of engine direct connection type IPMSG are rapidly changing, the constant dc link voltage control of power generation system is required. Therefore, two different implementations are considered: when the speed of IPMSG is less than base speed, boost control method is applied to maintain a constant DC link voltage by the direct torque and flux control (DTFC) within the current and voltage constraints. And, when exceeding the base speed, flux-weakening control method is applied to suppress the dc link voltage rises. In addition, a feed-forward controller is applied to improve the dynamic characteristics of maximum torque per ampere/voltage (MTPA/V) and flux-weakening operations. The feasibility of the proposed method is verified under various operating conditions with computer simulation and testing with the 3.5 kW IPMSG power generation system.