Transformer economic operation control system based on zero-crossing switching

The active power loss and reactive power loss nonlinear varied with the load, so the loss was controllable. This study built simulation experiment platform, subjects was two single-phase double winding transformer, based on method of transformer economic operation critical section. It introduced hardware and software design. Hardware circuits included electric parameters measurement circuit, AC contactor switching time measurement circuit, voltage or current zero-crossing point capture circuit and so on. Then the zero-crossing switching was put forward to reduce the transformer switching operation safety hazard. The experimental data shows load power and voltage current zero-crossing are detected exactly, AC contactor operation time was discrete, but declines with the supply voltage increasing, changes linearly. The accuracy rate, transformer economic operation and flexible switching with voltage¤t zero-crossing, is 94.3%.