Motor Current Coordination for EV Torque and Battery Self-Heating
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Solution Overview
Problem
Existing technologies do not effectively address the selective improvement of power performance or heat output in electric vehicles through cooperative control of battery self-heating and motor driving.
Innovation Solution
An energy conversion device with a motor, electronic control, and power battery system, controlled by a controller to manage the interaction between N line and phase currents to enhance motor performance or heat output based on vehicle conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If battery self-heating is performed using existing technologies, then the battery temperature can be maintained, but the power performance of the whole vehicle cannot be selectively improved and the heat output of the electric drive system cannot be selectively increased
Solution Approach 1:
The patent implements dynamic control of the bridge arms to switch between two operational modes: counteracting current crests and troughs to improve motor power performance, or superposing currents to increase heat output. This dynamic adaptability allows the system to selectively optimize for either power performance or heat output based on vehicle conditions, resolving the contradiction between versatility and control complexity.
Solution Approach 2:
The controller changes the operational parameters of the bridge arms by adjusting how they control current flow through the windings. By modifying the control strategy (counteracting vs. superposing current waveforms), the system can selectively improve power performance or increase heat output without adding physical hardware complexity, thus resolving the contradiction between adaptability and device complexity.
2Power
If the amplitudes of actual phase current at crest and trough are increased to improve motor torque, then the dynamic performance improves, but the electromagnetic interference and overcurrent protection triggers increase
Solution Approach 1:
The patent converts the harmful electromagnetic interference caused by high current amplitudes into a beneficial effect by using the N line current to counteract the phase current crests and troughs. This reduces the peak current amplitudes and associated electromagnetic interference while still maintaining the ability to improve motor torque when needed, thus resolving the contradiction between power output and electromagnetic interference.
Solution Approach 2:
The controller preliminarily counteracts the harmful effects of high current amplitudes by using the N line current to offset the phase current crests and troughs before they can cause excessive electromagnetic interference and trigger overcurrent protection. This preliminary anti-action reduces electromagnetic interference while preserving the ability to improve motor performance.
3Object-affected harmful factors
If the N line current and phase current are made to counteract each other to reduce current amplitudes, then electromagnetic interference is reduced, but the heat output of the electric drive system decreases
Solution Approach 1:
The system dynamically switches between counteracting current waveforms (to reduce electromagnetic interference) and superposing current waveforms (to increase heat output). This dynamic control allows selective optimization based on vehicle conditions, resolving the contradiction between reducing electromagnetic interference and maintaining heat output capability.
Solution Approach 2:
The same N line current control system serves multiple functions: it can counteract phase current to reduce electromagnetic interference and improve power performance, or it can superpose with phase current to increase heat output. This multi-functionality resolves the contradiction by making the system adaptable to different operational requirements without requiring separate systems.
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
Improves dynamic performance and heat output of electric vehicles by optimizing current utilization and reducing electromagnetic interference, allowing for selective enhancement of motor torque or heat generation as needed.
Implementation Method 1
a power battery, the power battery including a first battery pack and a second battery pack connected in series to the first battery pack
Implementation Method 2
a motor, the motor including at least two windings, and first ends of the at least two windings being connected together and leading out an N line
Implementation Method 3
control each of the bridge arms corresponding to the windings of the motor, to achieve cooperation between driving and battery self-heating, and control each of the bridge arms corresponding to the windings of the motor, to cause a crest and trough of an actual N line current flowing through the N line to counteract a crest and trough of an actual phase current flowing through each winding
Data Source
AI summary
An energy conversion device comprises: an electric motor, an electronic control, a traction battery and a controller. The controller is configured to control all bridge arms corresponding to windings of the electric motor, so that the collaboration of driving and battery self-heating is achieved, and the crest and trough of an actual N line current flowing through an N line of the electric motor to counteract or are superposed with the crest and trough of an actual phase current flowing through each phase of winding of the electric motor, thus reducing or increasing the amplitudes of the actual phase current of each phase of winding at the crest and trough, and thereby providing a greater phase current for the electric motor so as to drive the electric motor. Thus, the torque output by the electric motor is greater.