Rotating Machine Current Control Under Temperature Constraints
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Solution Overview
Problem
Existing rotating machine control systems face challenges in reducing losses and maintaining torque without using current command maps, especially when temperature increases, as they either require numerous current command patterns or neglect temperature information, leading to overheating and torque reduction.
Innovation Solution
A rotating machine control device that includes a temperature information acquisition unit and a current command generation unit with a constraint condition setting, optimization calculation, and constraint condition update unit to generate current command values based on torque, stator winding, and field winding conditions, without relying on current command maps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If current command maps are prepared for each winding temperature, then torque output is maintained, but device complexity increases exponentially
Solution Approach 1:
The patent changes the approach from discrete current command maps to continuous parameter-based optimization. The objective function and constraint conditions are formulated in terms of temperature parameters, allowing the system to adapt to any temperature condition without requiring pre-defined maps for each temperature point.
Solution Approach 2:
Instead of storing multiple current command maps, the patent creates a mathematical model (objective function + constraint conditions) that can generate optimal current commands on-demand. This model serves as a compact representation that replaces the need for storing numerous discrete maps.
2Loss of energy
If current command maps are used to maintain torque, then loss reduction is achieved, but manufacturing precision becomes difficult due to exponential parameter combinations
Solution Approach 1:
The patent transforms the discrete parameter configuration problem into a continuous optimization problem. By using temperature as a continuous parameter in the objective function and constraint conditions, the system achieves precise adaptation without the discretization errors inherent in map-based approaches.
Solution Approach 2:
The system transitions from static current command maps to dynamic optimization that continuously adapts to changing temperature conditions. The objective function and constraint conditions are evaluated in real-time based on current temperature, allowing the system to maintain precision across the entire operating range.
3Device complexity
If temperature information is not considered in current command generation, then device complexity is reduced, but reliability decreases due to overheating
Solution Approach 1:
The patent implements feedback by incorporating temperature information into the current command generation process. The temperature-dependent constraint conditions ensure that current commands are adjusted based on real-time temperature measurements, preventing overheating while maintaining system reliability.
Solution Approach 2:
The system performs preliminary action by proactively adjusting current commands based on temperature trends before overheating occurs. The constraint conditions are designed to prevent temperature-exceeding scenarios rather than reacting after overheating begins.
Data Source
AI summary
A rotating machine control device for controlling a rotating machine having a stator winding and a field winding includes a current command generation unit which generates a current command value on the basis of the temperature of the rotating machine. The current command generation unit includes a constraint condition setting unit which calculates a constraint condition on the basis of a torque command, stator winding voltage, stator winding current, and field winding current, an optimization calculation unit which calculates and outputs the current command value, using the constraint condition and an evaluation function, and a constraint condition update unit which updates the constraint condition on the basis of the temperature of the rotating machine. The current command generation unit calculates and outputs the current command value, using the updated constraint condition.