Product introduction: the constant pressure control, can be realized in the 0.01 Mpa pressure fluctuation range of high-precision constant pressure control, variable frequency soft start, eliminate the peak current of startup, avoid grid impact, through the cascade speed regulation to avoid electric shock, improve flexibility, put an end to light, compressor stop idling in the operation process, reduce the waste of invalid. High performance vector control, low frequency start torque, small running current, greatly reduce energy consumption.