Midpoint potential balancing system based on multi-level magnetic suspension bearing driver

A midpoint potential balancing system based on a multi-level magnetic suspension bearing driver, comprising:

• a three-level four-bridge arm driver, comprising a switch bridge arm module and a capacitor bridge arm connected in parallel, and provided to acquire winding current sampling data, and regulate a voltage of the switch bridge arm module based on a voltage control signal to balance a midpoint potential of the capacitor bridge arm module;
• a current controller, configured to receive the winding current sampling data, and obtain an average voltage of the switch bridge arm module based on the winding current sampling data;
• a midpoint voltage balancing unit, communicatively connected to the current controller, and configured to obtain a zero-sequence voltage based on the average voltage of the switch bridge arm module;
• a duty update unit, communicatively connected to the midpoint voltage balancing unit, and configured to receive the zero-sequence voltage and the average voltage of the switch bridge arm module, and obtain a switching time based on the zero-sequence voltage and the average voltage of the switch bridge arm module;
• a modulation unit, communicatively connected to the duty update unit, and configured to receive the switching time, and obtain the voltage control signal based on the switching time.