Dynamometer Electrical Machine Heating for Cold Testing
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Solution Overview
Problem
Dynamometer testing systems face challenges in accurately measuring vehicle characteristics under various conditions, especially in extreme weather, due to the increased complexity of vehicle transmissions and the need for costly equipment designed for low temperatures.
Innovation Solution
A method involving the use of standard three-phase asynchronous induction machines, where the electrical machine is heated by applying a current to the stator winding when the temperature is below a certain limit, using a representation of heat transfer to estimate the machine's average temperature and control the heating process, allowing operation in environments not designed for low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If specialized low-temperature equipment is used for dynamometer testing in extreme conditions, then measurement accuracy and reliability are improved, but device complexity and cost increase
Solution Approach 1:
The patent changes the temperature parameter of the electrical machine by applying controlled heating to raise the machine temperature from sub-zero conditions to acceptable operating temperatures before testing. This allows standard equipment to function reliably in extreme cold conditions without requiring specialized low-temperature design modifications.
Solution Approach 2:
The patent performs preliminary heating of the electrical machine before the actual dynamometer testing begins. This preliminary action ensures that the machine reaches appropriate operating temperature in advance, preventing measurement errors and reliability issues that would occur if testing were conducted directly in cold conditions.
2Ease of manufacture
If standard electrical machines are used in low temperature environments, then cost is reduced, but measurement accuracy and reliability deteriorate
Solution Approach 1:
The patent changes the temperature parameter of standard electrical machines by applying controlled heating. This allows inexpensive standard machines to operate reliably in cold environments by temporarily modifying their thermal state, eliminating the need for expensive cold-weather specialized equipment while maintaining measurement accuracy.
Solution Approach 2:
The patent converts the harmful effect of cold temperature on electrical machine performance into a controllable parameter by implementing active heating. The heating system transforms the thermal challenge into a manageable process, allowing standard equipment to overcome environmental limitations and achieve reliable operation in conditions previously unsuitable for such machines.
3Temperature
If heating current is applied to stator winding to raise machine temperature, then operational temperature is improved, but energy consumption increases
Solution Approach 1:
The patent implements feedback control by continuously monitoring the electrical machine temperature and adjusting the heating current accordingly. The controller compares the actual temperature with the desired temperature range and modulates the heating power to maintain optimal operating conditions, preventing excessive energy consumption while ensuring the machine reaches and maintains appropriate temperature for accurate testing.
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
Enables cost-efficient dynamometer testing by allowing standard electrical machines to operate effectively in extreme conditions without the need for specialized low-temperature designs, ensuring accurate vehicle testing in controlled environments.
Implementation Method 1
heating said electrical machine by applying a current to said stator winding
Data Source
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AI summary
The present invention relates to a method for use in dynamometer testing of a vehicle (100), the vehicle (100) including at least a first wheel shaft and at least one first vehicle power source for providing power to said first wheel shaft, said first wheel shaft being connected to a vehicle dynamometer system, said vehicle dynamometer system comprising a first controllable dynamometer power source (201) for providing power to said first wheel shaft, said first dynamometer power source being an electrical machine (201) comprising a stator and a rotor, said stator comprising a stator winding. The method includes: - determining whether a first temperature (T 1) is below a first temperature limit (T lim1), and - heating said electrical machine (201) by applying a current (I heat) to said stator winding when said first temperature (T 1) is below said first temperature limit (T lim1).