Method and system for suppressing direct-current side voltage oscillation

Abstract

The invention discloses a method and system for suppressing the direct-current side voltage oscillation. The method is applied to an urban rail vehicle comprising a linear motor traction system and comprises the following steps of determining the voltage oscillation quantity of the direct-current side voltage of an inverter; converting the voltage oscillation quantity into a slip frequency compensation quantity, and compensating the slip frequency compensation quantity on a given slip frequency of the linear motor; solving the stator frequency of the linear motor according to the compensated given slip frequency and the rotor frequency of the linear motor, and re-determining a coordinate conversion angle value in a synchronous rotation coordinate conversion formula of a vector control system according to the stator frequency; adjusting the output of the inverter with the redetermined vector control system to suppress the oscillation quantity. According to the invention, the given slipfrequency is compensated, and the output of the inverter is readjusted, so that the linear motor consumes the oscillation voltage at the direct current side of the inverter, the torque ripple of the linear motor does not happen easily, the overvoltage and overcurrent fault protection of the traction system is not easy to trigger, and the stability and driving safety of a traction system are improved.

Description

technical field [0001] The invention relates to the technical field of oscillation suppression, in particular to a method and system for suppressing DC side voltage oscillation. Background technique [0002] At present, linear motor traction systems are widely used in urban rail vehicles due to their advantages such as strong climbing ability, small turning radius and low cost. Please refer to figure 1 , figure 1 It is a vector control schematic diagram of a linear motor traction system in the prior art. In the prior art, the linear motor traction system is powered by a DC power supply filtered by an LC filter circuit, and then the inverter outputs three-phase AC power to the three-phase symmetrical windings a, b, and c of the linear motor, wherein, The stability of the three-phase alternating current is based on the control of the vector control system. [0003] The specific control process of the vector control system includes: 1) collecting the three-phase AC current ...

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Problems solved by technology

[0004] However, the existence of the LC filter circuit easily causes the DC side voltage oscillation of the inverter, which in turn causes the torque ripple of the linear motor, which easily triggers the overvoltage and overcurrent fault protection of the traction system, affecting driving safety.

However, the existing vector control system only controls the output of the inverter to stabilize, and cannot consume the oscillating voltage on the DC side, and thus cannot suppress the oscillation of the DC side voltage.

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