Frequency converter with direct-current bus capable of discharging rapidly at constant power and implementation method

The frequency converter comprises a main loop part, a control part and a rapid discharge part, the rapid discharge part is composed of discharge capacitors C1 and C2 and contactors K1 and K2, after normally open contacts of the C1 and the K1 and normally open contacts of the C2 and the K2 are connected in series, one end is connected to the middle point of the bus, and the other end is connected to a positive bus and a negative bus through IGBTs on the upper bridge arm and the lower bridge arm of different bridge arms. The discharge control method comprises the following steps: a) power-off detection; b) detecting a trigger signal; c) bus voltage detection; d) fault judgment; e) closing the contactor; f) outputting a driving signal; and g) bus voltage judgment. According to the frequency converter with the direct-current bus capable of achieving constant-power rapid discharging and the control method, energy consumption is formed by means of the resistance between the collector electrode and the emitter elect