High-voltage frequency conversion speed control system, with high-speed DSP as the control core, using space vector technology, power unit series multi-level technology and many other advanced technologies. With high reliability, easy operation, high performance and small size as the design goal, to meet the needs of users of various types of load speed regulation and energy saving, improve the production process, is a high-high-voltage source type inverter. Its harmonic is far less than the national standard of IEE519-2014, with high input power factor and good waveform quality, without the need to use input harmonic filter, power factor compensation devices and output filters. There is no harmonic-induced additional motor heating and torque pulsation, noise, common mode voltage and other problems, which can be applied to synchronous motors (including permanent magnet synchronous motors) and asynchronous motors in two/four quadrants.