PCS Function Experiments: Grid-Off Grid Switching & Parallel Operation

This document details key experiments for Power Conversion System (PCS) functions in energy storage systems. It covers grid-connected and off-grid switching control, including active seamless switching via frequency and amplitude detection, and passive non-seamless switching triggered by voltage threshold violations. Synchronous grid-connected switching is described with passive protection device control and automatic PCS-based synchronization. Off-grid operation with nonlinear loads and harmonic suppression methods is presented to reduce voltage distortion. Load switching tests for capacitive and reactor loads are included. The black start control section demonstrates impact load startup and load shedding. Multi-unit parallel operation tests show power sharing among three PCS units under resistive and motor loads, with stable performance during unit disconnection and reconnection. These experiments validate PCS reliability, fast switching, and robust control for microgrid applications.