Voltage-Disturbance Identification and Fast Transfer Control of an IGCT-Based Hybrid Solid-State Transfer Switch

Voltage disturbances in power distribution networks can interrupt power supply to sensitive loads, thus requiring fast and reliable power switching. For low-voltage distribution networks, this study proposes a hybrid solid-state transfer switch based on IGCT, which integrates a magnetically controlled switch and combines voltage disturbance identification and fast switching control methods. The proposed method processes the acquired three-phase voltage waveforms through a hierarchical control architecture. A transient triggering strategy based on dq transform is used to detect abnormal voltage conditions and initiate the switching process, while a deep neural network model with multi-scale feature fusion identifies disturbances from transient voltage features. The identification method was evaluated under simulated noise conditions, and the switching performance was verified on a physical prototype platform. At a signal-to-noise ratio of 20 dB, the proposed model achieved a fault identification accuracy of over 95% under the tested operating conditions. Under single-phase full voltage interruption conditions, the switching time of the prototype was 4.91 ms, approximately 62.2% shorter than the 12.99 ms measured for the tested commercial thyristor-based solid-state transfer switch (Socomec). Under three-phase full voltage interruption conditions, the switching time of the prototype was 6.80 ms. The results show that the proposed hybrid solid-state transfer switch integrates voltage disturbance identification and fast switching control functions, providing a feasible solution for improving the power supply continuity of sensitive loads.