Integrated Motor Control Module for Inductance Reduction
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Solution Overview
Problem
In electric motor systems, particularly those used in vehicles, the increased distance between the control unit and the motor leads to larger current loops and higher inductance, resulting in higher voltage transients and the need for more powerful, slower switching inverter switches, which can be constrained by environmental conditions such as those found in a vehicle wheel environment.
Innovation Solution
A control module with integrated cooling and structural support for printed circuit boards, featuring a heat sink with cooling channels, annular capacitors to reduce voltage ripple, and a modular design with elastomer encapsulation for environmental protection and shock absorption, allowing for reduced inductance and improved operational reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the control unit is located at a greater distance from the electric motor, then environmental conditions are improved, but the current loop size increases leading to higher inductance and voltage transients
Solution Approach 1:
The control unit is integrated with the electric motor into a single control module, merging the control unit, inverter switches, and motor together. This eliminates the harmful effect of large current loops and voltage transients by minimizing the distance between components, while still providing environmental protection through the integrated design.
Solution Approach 2:
A printed circuit board is introduced as an intermediary carrier that integrates the inverter switches and control unit components. The PCB provides a structured platform that minimizes current loop areas while organizing the electrical connections efficiently between the control unit and motor.
2Reliability
If higher power rated inverter switches are used to handle voltage transients, then reliability is improved, but switching speed decreases and switching losses increase
Solution Approach 1:
By merging the control unit and motor into an integrated control module, the voltage transients are minimized at their source. This allows the use of inverter switches with lower power ratings that can switch faster and with less loss, as the integrated design prevents the formation of large voltage transients in the first place.
3Reliability
If the control unit is mounted on or adjacent to the electric motor, then current loop size is reduced, but environmental protection becomes more difficult
Solution Approach 1:
The control unit, inverter switches, and motor are merged into a single integrated control module with a common housing. This integration maintains the benefit of small current loops while providing unified environmental protection through the housing that shields all sensitive electronic components from harsh conditions simultaneously.
4Reliability
If inverter switches with slower switching speeds are used, then voltage transient handling is improved, but switching losses increase
Solution Approach 1:
The integrated control module design minimizes voltage transients by reducing the current loop area between the control unit and motor. This allows the use of fast-switching inverter switches that operate with high efficiency and low losses, as the integrated architecture prevents the generation of large voltage transients that would require slower switching to handle.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides effective cooling and environmental protection to the control module, reduces inductance, and enhances the operational reliability of the electric motor by minimizing voltage transients and accommodating harsh environmental conditions, while also providing structural support and shock absorption.
Implementation Method 1
a heat sink with cooling channels, allowing for reduced inductance and improved operational reliability
Implementation Method 2
cooling channels, allowing for reduced inductance and improved operational reliability
Implementation Method 3
a modular design with elastomer encapsulation for environmental protection and shock absorption
Implementation Method 4
annular capacitors to reduce voltage ripple
Data Source
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AI summary
A control module for an electric motor having a stator that includes a first surface, wherein cooling fluid is arranged to flow within the stator for providing cooling to the first surface, the power module comprising a power device having switching elements for controlling current flow in coil windings mounted on the stator; a control device for controlling the operation of the switching devices; a housing with a first side for mounting to the first surface of the stator, wherein the first side of the housing includes an aperture for allowing a portion of the power device to be in contract with the first surface of the stator when the housing is mounted to the first surface for providing cooling to the switching elements, wherein the control device is arranged to be mounted in the housing on an opposite side of the power device to the first side of the housing and an elastomer is located over the power device and the control device for providing an electrical insulation barrier over the switches on the power device and electrical components on the control device.