Field-Guided Motor Braking Control Under Battery Charging Limits
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Solution Overview
Problem
Existing field-guided electric motors experience time delays in transitioning from braking to acceleration due to limitations in torque-forming motor current components, leading to inefficient braking and user annoyance.
Innovation Solution
A method and device for operating a field-guided electric motor that divides the braking mode into two sections: a first section with a constant current amplitude and a second section with a variable amplitude, adjusting the field-forming and torque-forming motor current components to optimize braking power and allow seamless transitions between these phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the torque-forming motor current component is increased to enable faster braking, then the braking speed is improved, but the battery pack charging current limit is exceeded
Solution Approach 1:
The braking process is segmented into two distinct sections: a first braking section with constant current amplitude for rapid deceleration, and a second braking section with variable current amplitude for controlled stopping. This segmentation allows the system to achieve fast braking while respecting battery charging limits by adjusting the field-forming current component in each section.
Solution Approach 2:
The invention changes the parameters of the motor current by adjusting the field-forming current component (id) during braking. By dynamically modifying this parameter, the system optimizes the torque-forming current component (iq) for rapid braking while ensuring the total current remains within battery charging capabilities.
2Use of energy by moving object
If the electric motor is in braking mode, then energy recovery is achieved, but time delays occur when transitioning to acceleration
Solution Approach 1:
The control arrangement prepares for potential acceleration during the braking process by maintaining appropriate field-forming current components. This preliminary preparation ensures that when the operating element is reactivated, the motor can transition to acceleration mode immediately without delay, while still achieving effective braking and energy recovery.
3Speed
If the field-forming motor current component is adjusted for rapid braking, then braking performance is improved, but control complexity increases
Solution Approach 1:
The control arrangement continuously monitors the motor's operating state, including rotor position and current components, and adjusts the field-forming current accordingly. This feedback mechanism enables rapid braking performance while managing control complexity through automated real-time adjustments based on actual motor conditions.
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
The method ensures rapid braking and efficient energy recovery by optimizing the current components, allowing for rapid braking and immediate acceleration without exceeding battery charging limits.
Implementation Method 1
in a motor mode, to form a driving electromagnetic rotary field, the field windings are configured to be energized by the control arrangement from the battery pack
Implementation Method 2
in a braking mode of the electric motor, voltages induced in the field windings of the stator when the rotor is running bring about a torque-forming motor-current component
Data Source
AI summary
A method and a device are for operating a field-guided electric motor on a battery pack. In a motor mode, the motor current includes a field-forming motor current component and a torque-forming motor current component, which form a current amplitude of the motor current. In order to brake the electric motor fast with the option of possibly switching over to accelerating the electric motor at any time, provision is made for dividing the braking mode into two temporally separate braking sections. In a first braking section, the current amplitude of the motor current is kept constant by adjusting the field-forming motor current component. In a second braking section, the current amplitude of the motor current is variable. The switching of the braking mode over from the first braking section to the second braking section takes place when there is a fall below a predetermined speed of the electric motor.