SOGI-Based Control Strategy for Single-Phase Hybrid Transformer

With the access of large-scale new energy and power electronic equipment, it brings the problem of voltage fluctuation to the new power system. For this reason, Hybrid Transformer can achieve fast and continuous regulation of the node voltage, which improves the voltage stability at the grid-connected point. For single-phase Hybrid Transformer, their inverter-side control suffers from the problems of not being able to track AC quantities well and being prone to resonance. This paper proposes a single-phase Hybrid Transformer control strategy based on SOGI (Second Order General Integrator, SOGI). The output voltage of the inverter side is sampled and the quadrature components with phase difference of 90° are generated by SOGI, and the quadrature components are controlled by coordinate transformation. According to this control method, the simulation model of 3 kV/100kVA single-phase Hybrid Transformer is built based on the Matlab/Simulink platform, and under the working condition of 10% transient drop of primary-side voltage, 10% output voltage is compensated within 5 week waves (100 ms), which verifies the feasibility of this control method.