The invention discloses a dual-PWM variable frequency power supply feedback energy
processing device and method, wherein the device comprises a
signal collection circuit and a braking unit, and the
signal collection circuit is electrically connected with a connection point of two serially connected
DC bus capacitors; the braking unit comprises a braking
resistor, and the braking unit is connectedin parallel with the two serially connected
DC bus capacitors; the braking unit and / or the
signal collection circuit is electrically connected with a controller respectively. During the operation, thesignal collection circuit collects a
DC bus voltage in real time and transmits the
DC bus voltage to the controller, the controller compares the
DC bus voltage with a preset threshold Ua and / or a preset threshold Ub, and controls a
PWM rectifier to switch between a rectifying state and an active
insertion state or stop working, or / and controls braking current to flow by the braking
resistor or not according to the comparison result, thereby realizing the two-way flow of the energy between a
power grid side and a load side and avoiding faults caused by the feedback energy, the operation is safe and reliable, and the cost is low.