Multi-motor integrated controller support capacitor capacity calculating method

Abstract

The invention discloses a multi-motor integrated controller support capacitor capacity calculating method comprising the following steps: a relation between rated reactive power and frequency of a motor rated line current provided by a support capacitor is used, an expression, including support capacitor capacity as a parameter, for a voltage fluctuation peak-to-peak value [delta]U1 indicating motor frequency multiplication times is obtained; a relation between active power provided by the support capacitor and switch frequency of a multi-motor integrated controller is used, an expression, including the support capacitor capacity as a parameter, for a voltage fluctuation peak-to-peak value [delta]U2 indicating switch frequency multiplication is obtained; the support capacitor capacity is calculated based on a relation between a busbar voltage peak-to-peak value and [delta]U1 and [delta]U2 as well as a limit value of the busbar voltage peak-to-peak value. Via the method disclosed in theinvention, calculation of key parameters of the capacitor can be optimized, and negative influence exerted by capacitor parameters on a system can be lowered; requirement of a motor driving system for capacity, parasitic inductance and rated voltage of the capacitor can be calculated accurately.

Description

technical field [0001] The invention relates to the technical field of automatic control, in particular to a method for calculating the supporting capacity of a multi-motor integrated controller. Background technique [0002] The controller for controlling a single motor has been widely used in China, and the corresponding support capacitor selection technology has been relatively mature. However, the support capacitor type selection technology for the multi-motor integrated controller still needs to be developed. The following takes the dual-motor integrated controller as an example to illustrate the existing technology for this kind of multi-motor integrated controller. [0003] Dual-motor integrated controller is a controller that controls two motors to work at the same time. Each motor has two working conditions of braking and traction, so the dual-motor control system has 4 working conditions, which can match various vehicles Control Strategy. Today's new energy buses...

AI Technical Summary

Problems solved by technology

[0006] For the calculation of the capacity of the supporting capacitor of the two-level three-phase bridge circuit, simple formulas are often used in the prior art to directly calculate the capacity of the capacitor, and the selection of some parameters is inaccurate and lacks sufficient theoretical support.

Moreover, for the calculation of the capacitance capacity of the dual-motor control system, it is generally used to calculate the capacitance required by each motor system separately, consider the margin, and then add the capacity directly. This kind of superposition of the margin seriously wastes the capacitance. capacity, increased cost

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