TRACTION CONVERTER HAVING SECONDARY FILTERING CIRCUIT

摘要

A traction converter having a secondary filtering circuit (2). The traction converter comprises a rectifier circuit (1), a secondary filtering circuit and an inverter circuit (3) that are sequentially connected between a positive terminal (VDC+) and a negative terminal (VDC-) of a bus. The rectifier circuit comprises at least one parallel four-quadrant rectifier (11, 12). The secondary filtering circuit is used for filtering secondary harmonics and comprises at least two filtering capacitors (C1, C2, C3) connected in parallel, at least two filtering inductors (L1, L2) connected in parallel, and at least one discharging resistor (R1, R2). The at least one discharging resistor is connected in series and then connected in parallel at two ends of the filtering capacitor, and the filtering inductors are connected in series to the filtering capacitors. The inverter circuit comprises at least one parallel three-phase inverter (31, 32) that is respectively connected to at least one traction motor. By filtering secondary harmonics in bus voltage, the voltage input into the inverter is accurate and reliable, and safe and reliable driving of the traction motor can be ensured.