Isolation Transformer-Based Zero-Sequence Current Suppression Method for Microgrid Diesel Generator Systems

Based on the existing problem of a small-capacity 10 kV feeder network in isolated islands, the original system wiring external asymmetric operation or fault can easily lead to generator tripping. By providing a new system wiring method for the isolated microgrid, i.e., a new system wiring method that uses the parallel bus of the generator group to be isolated from the feeder bus, and a transformer with different wiring methods on the primary and secondary sides to achieve isolation of the external feeder bus from the parallel bus of the generator, simulation analysis is carried out by electromagnetic transient simulation software PSCAD, involving new primary system wiring, additional isolation transformers and different neutral grounding methods on the fault zero-sequence current, and finally verifying the effectiveness of the new system wiring.