Thin-film capacitor integrating EMC and discharge functions and motor controller thereof

Abstract

The invention discloses a thin-film capacitor integrating EMC and discharge functions and a motor controller thereof. The thin-film capacitor comprises a capacitor shell with a top seal and a bottom opening, and a heat dissipation upper cover and a water cooling bottom plate which are arranged at the upper and lower ends of the capacitor shell. A heat conduction insulation pad, a laminated busbarand an X capacitor core roll are sequentially arranged in the capacitor shell from bottom to top. The laminated busbar is provided with an EMC module comprising a Y capacitor, a bleeder resistor and aPCB, the capacitor shell is filled with an epoxy packaging adhesive to package the X capacitor core roll and the EMC module, and the surface of the capacitor shell is provided with a magnetic ring for an input terminal of the laminated busbar to pass through. When the thin-film capacitor is installed in the motor controller shell, the top and the bottom of the thin-film capacitor are both provided with cooling designs, and the water channel heat dissipation surface of the motor controller shell and the air cooling heat dissipation surface of the controller upper cover can be used for double-surface cooling at the same time.

Description

technical field [0001] The invention relates to a film capacitor for a motor controller, in particular to a double-sided water-cooled film capacitor with integrated EMC and discharge functions and a motor controller thereof. Background technique [0002] At present, the motor power and power density of new energy vehicles continue to increase, and the demand for the capacity of the X capacitor in the motor controller is also increasing, which will lead to serious internal heating of the capacitor and the increase in the overall volume, which makes it unfavorable on the one hand. Improving the power density of the motor controller, on the other hand, also brings risks to the reliability of the motor controller. Traditional heat dissipation methods can no longer meet the reliability requirements of capacitors used in high-power motor controllers. In addition, with the current requirements for electromagnetic compatibility of electric vehicles and the requirements for the disc...

AI Technical Summary

Problems solved by technology

[0002] At present, the motor power and power density of new energy vehicles continue to increase, and the demand for the capacity of the X capacitor in the motor controller is also increasing, which will lead to serious internal heating of the capacitor and the increase in the overall volume, which makes it unfavorable on the one hand. Improving the power density of the motor controller, on the other hand, also brings risks to the reliability of the motor controller

Traditional heat dissipation methods can no longer meet the reliability requirements of capacitors used in high-power motor controllers

In addition, with the current requirements for electromagnetic compatibility of electric vehicles and the requirements for the discharge rate of capacitors, the EMC performance and capacitor discharge capability of motor controllers are particularly important. Traditional film capacitors for motor controllers are only used to suppress differential mode interference. The X capacitor, while the EMC module and the discharge module for capacitor discharge are installed in other positions in the motor controller, which causes a waste of space, also prolongs and deteriorates the signal conduction loop, reduces EMC performance and discharge rate, and these It is difficult to fix the device well, and there is a risk of failure due to vibration

In terms of installation methods, the current film capacitors only use the motor controller shell as the heat exchange surface, but the motor controller cover is difficult to be used. In addition, the motor controller cover is usually designed to be thinner and flatter, so Poor seismic performance

[0003] Chinese patent CN110335755A discloses a water-cooled film capacitor and motor controller with integrated safety filter capacitors. This patent has the following defects: 1. It integrates related EMC devices and water-cooling functions, but does not have a discharge module, so it cannot be quickly discharged; 2. .The EMC module and circuit board are installed outside the capacitor shell, which is easy to cause bump damage, poor firmness and insulation performance; 3. Ferrite common mode inductor (a kind of magnetic ring) is potted inside the capacitor shell, The high temperature of the epoxy resin during potting will damage the magnetic material; 4. Vertical cooling water pipes are installed on both sides of the capacitor case, the heat dissipation area is small and does not cover the copper bars and core coils, and it must be connected to the water cooling chamber of the external IGBT module , there will be a risk of coolant leakage; the capacitor case only forms a heat exchange surface with the IGBT module at the top, and the heat dissipation surface is not fully utilized; Poor feasibility of epoxy potting process

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