Parameter design and hot seamless transfer of single-phase synchronverter

This paper reveals the parameter design of single-phase synchronverter (SPSV) and proposes a hot seamless transfer method for SPSV. The design challenge of SPSV lies in its necessary for single-phase power calculation to generate an average value of active/reactive power and the high order system feature caused by the virtual inertia element. The small signal analysis shows that the low-pass filter time constant and SPSV active power loop time constant determine the system damping ratio together. Then we proposed a SPSV parameter design method to provide a proper damping ratio and guarantee system small signal stability. Based on the SPSV parameter design method, a hot seamless-transfer is proposed. During the disconnection and reconnection processes, SPSV can maintain a non-zero power output, which is essential for the critical local loads when the SPSV serves as an uninterrupted power source. The SPSV parameter design method and hot seamless transfer are investigated by simulation. Finally, a 500 W SPSV prototype is built for further demonstration.