Heat Pump Electric Motor Control for Increased Heating Capacity
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Solution Overview
Problem
The heating capacity of heat pump systems in electric vehicles is insufficient at low ambient temperatures, necessitating additional electrical heaters, which complicates HVAC-system design and increases costs.
Innovation Solution
A method and control unit that control the electric motor of the heat pump system to increase heat losses and recover heat emitted, allowing for higher heat output while maintaining efficiency by switching between optimal and non-optimal operation modes based on heating demands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the electric motor is controlled in the second control mode to increase heat losses, then the heating capacity of the heat pump system is improved, but the efficiency of the electric motor deteriorates
Solution Approach 1:
The patent converts the harmful heat losses from the electric motor into a beneficial heating source. By controlling the motor in a second control mode that deliberately increases heat losses, the system recovers this previously wasted energy to heat the working fluid, thereby increasing overall heating capacity while accepting reduced motor efficiency as a trade-off that is offset by the recovered heat energy.
2Temperature
If an additional electrical heater is provided to increase heating capacity, then the heating performance is improved, but the device complexity and cost increase
Solution Approach 1:
The patent makes the electric motor multi-functional by having it serve both its primary function of driving the compressor and a secondary function of heating the working fluid through controlled heat losses. This eliminates the need for separate heating devices, reducing system complexity and cost while maintaining enhanced heating capacity.
Solution Approach 2:
The system uses its own electric motor as the heat source for heating the working fluid, rather than requiring an external or additional heating device. The motor serves itself by converting part of its electrical energy into heat that is then recovered to heat the working fluid, simplifying the overall system architecture.
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
This approach enhances the heating capacity of the heat pump system, potentially eliminating the need for additional heaters at low temperatures, simplifying the HVAC system and reducing costs.
Implementation Method 1
controlling the electrical motor in a way creating higher heat losses of the electric motor for a given output torque of the electric motor
Implementation Method 2
recovering heat emitted from the electric motor by heating the working fluid
Data Source
AI summary
A method for controlling a heat pump system. The heat pump system includes a compressor for compressing a working fluid of the heat pump system and an electric motor for providing an output torque for driving the compressor. The method includes the steps of recovering heat emitted from the electric motor by heating the working fluid, providing a first control mode and a second control mode for the electric motor, and controlling the electrical motor in a way creating higher heat losses of the electric motor for a given output torque of the electric motor in the second control mode than in the first control mode.