Torque Compensation Apparatus for Motor Iron Loss
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Solution Overview
Problem
Conventional methods for compensating for torque changes in driving motors due to temperature and speed variations are time-consuming and inefficient, particularly in configuring current control maps, which affects torque control performance and fuel efficiency in hybrid vehicles.
Innovation Solution
A method and apparatus that calculate a compensation torque based on the current magnitude and speed of the driving motor, using a magnetic flux-based current order map generated from battery voltage, electrical angular velocity, and torque order, to minimize torque errors and optimize current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods (estimating secondary resistance or configuring n current control maps) are used to compensate for torque changes, then torque control performance can be maintained, but significant time and effort are required to configure the current control maps
Solution Approach 1:
The patent extracts the iron loss torque as a separate compensable component from the total torque. By identifying and isolating the iron loss torque component that varies with temperature and speed, the system can compensate for it independently without needing to reconfigure entire current control maps, thus maintaining torque control performance while reducing configuration time
Solution Approach 2:
The patent changes the approach from configuring complete current control maps to adjusting torque compensation parameters based on temperature and speed. By using parameter-based compensation for iron loss torque instead of map-based control, the system maintains reliability while significantly reducing the time required for configuration
2Measurement precision
If n current control maps are configured depending on temperature with interpolation, then torque accuracy is improved, but the complexity of configuring and applying all combined current orders increases
Solution Approach 1:
The patent extracts the iron loss torque component as a separate function of temperature and speed. By compensating for this specific component rather than reconfiguring entire current control maps, the system achieves torque accuracy improvement without the complexity of managing multiple maps and their combinations
Solution Approach 2:
The patent transitions from a map-based approach requiring configuration of n current control maps to a parameter-based approach where iron loss torque is calculated using temperature and speed parameters. This reduces device complexity while maintaining torque accuracy through direct parameter adjustment
3Adaptability or versatility
If all current orders are applied in all driving regions to measure torque and calculate MTPA curve, then comprehensive torque control is achieved, but the time and computational effort required increases significantly
Solution Approach 1:
The patent performs preliminary characterization of iron loss torque as a function of temperature and speed. By pre-establishing the iron loss torque model, the system achieves comprehensive torque control adaptability without needing to repeatedly measure torque and calculate MTPA curves during operation, thus reducing time and computational effort
Data Source
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AI summary
An apparatus for compensating for a torque for a current order of a driving motor includes: a current order generator configured to: i) receive a torque order (Tref*), ii) generate a magnetic flux-based current order map using a generated driving point ratio (1/λmax), and iii) generate a current order using the generated current order map; and an iron loss torque compensator configured to extract an iron loss torque compensation value for the generated current order and a speed (Wrpm) of the driving motor.