Motor Regeneration Control via Voltage Threshold Detection
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Solution Overview
Problem
Current methods for managing electric motor regeneration often require additional hardware components, increasing weight and cost, and fail to effectively prevent duty cycle decreases during regeneration conditions, which can lead to overvoltage and reduced motor performance.
Innovation Solution
A method and apparatus that utilize a voltage sensor and controller to identify instantaneous and average voltages, compute a new average voltage with a weight factor, and compare it to a threshold to determine regeneration conditions, thereby controlling the motor's duty cycle to prevent undesired decreases, using a rate limiter and adjusting the weight factor to manage regeneration without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hardware components such as shunt resistor and voltage comparator circuit are used to manage regeneration, then regeneration can be detected and managed, but the weight and cost of the electric motor increase
Solution Approach 1:
The patent replaces hardware-based voltage detection (shunt resistor and voltage comparator circuit) with a software-based detection method using a microcontroller to read voltage from an existing sensor. This substitution eliminates additional hardware components while maintaining regeneration detection capability, directly resolving the contradiction between reliability and weight.
Solution Approach 2:
The patent utilizes existing voltage sensor and microcontroller that serve multiple functions in the motor control system, rather than adding dedicated hardware solely for regeneration detection. This multi-functional approach maintains regeneration management capability without increasing motor weight.
2Reliability
If hardware components such as shunt resistor and voltage comparator circuit are used to manage regeneration, then regeneration can be detected and managed, but the cost of the electric motor increases
Solution Approach 1:
The patent replaces expensive hardware components (shunt resistor and voltage comparator circuit) with software-based detection using existing microcontroller and sensor infrastructure. This substitution reduces component count and manufacturing complexity, directly addressing the cost issue while maintaining regeneration management reliability.
Solution Approach 2:
The system uses its existing control infrastructure (microcontroller and voltage sensor) to perform regeneration detection and management without requiring external dedicated hardware. This self-service approach eliminates additional manufacturing costs while maintaining the required functionality.
3Speed
If duty cycle is allowed to decrease during regeneration conditions, then motor speed can be controlled, but overvoltage occurs and motor performance is reduced
Solution Approach 1:
The patent implements feedback control by continuously monitoring voltage during duty cycle adjustments and preventing duty cycle decreases when regeneration conditions are detected. This feedback mechanism ensures motor speed control is maintained only when it doesn't trigger harmful regeneration, resolving the contradiction between speed control and performance reliability.
Solution Approach 2:
The patent applies preliminary anti-action by detecting regeneration conditions before they cause harmful effects and preemptively preventing duty cycle decreases that would trigger or worsen regeneration. This proactive approach maintains motor performance by avoiding overvoltage conditions while still allowing speed control within safe parameters.
Data Source
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AI summary
A method and apparatus for controlling regeneration for a motor (202). An instantaneous voltage provided by a power supply (205) to the motor (202) is identified using a voltage signal received from a voltage sensor (210). A new average voltage is computed for the motor using the instantaneous voltage (214), a previously computed average voltage (218), and a weight factor (220) for the instantaneous voltage. A difference (222) between the new average voltage and the instantaneous voltage is compared to a selected threshold (224) to determine whether a regeneration condition exists. Operation of the motor (202) is controlled such that a duty cycle of the motor does not decrease in response to a determination that the regeneration condition exists.