The fully digital control architecture centers on dual motor-control DSPs, high-density CPLD and FPGA processors, and integrated PLC logic — all interconnected via high-speed fiber-optic communication links. Phase-shifted SPWM waveforms from each cascaded power unit are superimposed to produce a near-perfect sinusoidal output, substantially reducing harmonic content and voltage dv/dt. The result is a "zero-harmonic" output that protects motor insulation and eliminates the need for additional output filters.
A key reliability feature is the automatic power unit bypass: if any individual unit develops a fault, the system automatically bypasses it without operator intervention, allowing the remaining units in each phase to continue operating — typically without load derating. An automatic line-frequency bypass further ensures that, in the event of a drive fault, the motor can be instantly switched back to direct grid connection, keeping critical processes running without interruption.
With over 16,000 systems in service across China and in more than 40 countries worldwide, ZINVERT represents a proven, high-availability platform for motor speed control and industrial energy saving. Flagship applications include 300MW–600MW thermal power feedwater pump drives, 600MW+ combined induced draft fan drives, and extra-large capacity sintering main exhauster drives for the steel industry — positioning ZINVERT as a direct competitor to leading international brands in ultra-high-capacity applications.