Vehicle Generator-Motor Converter Control for Fast Mode Shifting
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Solution Overview
Problem
Existing vehicle generator-motor systems face issues with unintended power generation and excessive torque due to residual field magnetic flux when shifting from driving to stopping modes, leading to inefficient energy consumption and mode shifting delays.
Innovation Solution
A power converter and control method that dynamically adjusts field current levels and energization strategies based on the next operating mode, allowing for prompt shifting without additional components or circuits, by controlling the field and armature windings to prevent unintended power generation and torque fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If field current is gradually reduced to prevent unintended power generation, then power generation control is improved, but mode shifting speed deteriorates
Solution Approach 1:
The patent applies dynamics by making the field current reduction rate variable rather than fixed. The control device adjusts the reduction rate based on real-time operating conditions, allowing fast reduction when safe and slow reduction when power generation is needed, thus resolving the contradiction between reliable power generation control and fast mode shifting.
Solution Approach 2:
The patent changes the parameter of field current reduction rate dynamically. By adjusting this parameter according to operating conditions (such as armature current level, rotation speed), the system achieves both reliable power generation control and fast mode shifting capability.
2Power
If armature energization is continued during field current reduction, then power generation can be achieved, but energy wastage increases
Solution Approach 1:
The patent applies local quality by differentiating the control strategy based on the target mode. When transitioning to power generation mode, armature energization is maintained locally during field current reduction to enable immediate power generation. When transitioning to other modes, armature energization is stopped to avoid energy wastage.
Solution Approach 2:
The patent dynamically adjusts armature energization status based on the target operating mode. The control device determines whether to maintain or stop armature energization during field current reduction, optimizing the balance between power generation capability and energy efficiency.
3Reliability
If field current reduction is performed before armature stopping, then unintended power generation is prevented, but torque fluctuation occurs
Solution Approach 1:
The patent applies preliminary action by performing field current reduction before stopping armature energization when transitioning to non-power generation modes. This preliminary reduction of field current prevents residual magnetic flux from causing unintended power generation and excessive braking torque, thereby maintaining torque stability.
Solution Approach 2:
The patent applies preliminary anti-action by reducing field current in advance to counteract the potential harmful effect of residual magnetic flux. This preliminary reduction prevents the generation of excessive braking torque that would otherwise occur when armature energization is stopped while field current remains high.
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 efficient and prompt mode shifting by preventing unintended power generation and excessive torque, reducing energy wastage and ensuring seamless transitions between operating modes without additional hardware costs.
Implementation Method 1
a field winding generator-motor which operates as a motor at the time of starting an engine and assisting torque and operates also as a generator after the start
Implementation Method 2
an armature winding and a field winding, which is mountable mainly on a vehicle and which operates as a motor at the time of starting an engine and assisting torque
Implementation Method 3
operates also as a generator after the start
Data Source
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AI summary
Provided are a power converter for a vehicle generator-motor and a method for controlling a vehicle generator-motor, which is used for a field winding type vehicle generator-motor configured to perform control in accordance with an external operating command in which a power converter is connected to a rotating electrical machine including a field winding and an armature winding. When the generator-motor shifts from a driving state to another operating mode, a method of stopping a driving mode is switched in accordance with an operating mode to be shifted, to thereby shift the operating mode promptly without generating an unintended power generation, an excess power generation, and an excess torque fluctuation.