Hybrid Generator Control Device Voltage Torque Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Field winding type rotary generator-motors in hybrid vehicles face issues with engine stalling due to unstable engine output during start-up and idling, caused by uncontrolled generated voltage and torque, leading to potential overvoltage or excessive torque during power generation.
Innovation Solution
A control device and method for a power converter that includes a control selection section to output the minimum value between generated voltage and torque control outputs, using a B-terminal voltage detection, field current detection, and rotation speed calculation to control the field current, thereby setting an upper limit for generated voltage or torque to prevent overvoltage or excessive torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If generated voltage control is performed without torque control, then voltage stability is improved, but engine stalling occurs due to excessive torque
Solution Approach 1:
The control system dynamically switches between generated voltage control and generated torque control based on operating conditions. During normal operation, generated voltage control maintains stable voltage output. During engine start or idle conditions, generated torque control prevents excessive torque that would cause engine stalling, thus adapting the control strategy to different operational states.
Solution Approach 2:
The control device changes the controlled parameter from voltage to torque based on engine operating conditions. When the engine is starting or idling, the control parameter is switched to torque to limit generated torque and prevent stalling. When the engine is running normally, the control parameter is voltage to maintain stable voltage output, thus changing parameters according to operational requirements.
2Reliability
If generated torque control is performed without voltage control, then engine stalling is prevented, but overvoltage occurs during power generation
Solution Approach 1:
The control system dynamically selects between torque control and voltage control based on real-time operating conditions. During engine start or idle, torque control is activated to prevent stalling. During normal power generation, voltage control is activated to maintain stable voltage output, thus dynamically adapting the control strategy to prevent both overvoltage and engine stalling.
Solution Approach 2:
The control device changes the controlled parameter from torque to voltage based on engine operating conditions. When the engine is running normally, the control parameter is voltage to maintain stable voltage output. When the engine is starting or idling, the control parameter is switched to torque to limit generated torque and prevent stalling, thus changing parameters according to operational requirements.
3Productivity
If field current is increased to increase power generation, then power generation capacity is improved, but excessive torque is generated causing engine stalling
Solution Approach 1:
The control device changes the controlled parameter from current (which increases power generation) to torque during engine start or idle conditions. By controlling torque instead of current, the system limits the generated torque to prevent engine stalling while still allowing power generation to occur, thus changing the control parameter to resolve the contradiction between power generation capacity and engine stability.
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
Prevents engine stalling by maintaining stable engine output by setting an upper limit for generated voltage or torque, ensuring efficient power generation without overvoltage or excessive torque, thus enhancing the reliability of hybrid vehicle systems.
Implementation Method 1
a field winding type rotary generator-motor capable of control by a field current instead of using a rotor incorporating a permanent magnet
Data Source
AI summary
To provide an upper limit of a generated voltage or generated torque, to thereby prevent the occurrence of an overvoltage or excessive torque during power generation, a control selection section (308) chooses and outputs a minimum value between a control output of a generated voltage control section (306) for controlling a field current so that a B-terminal voltage of a polyphase AC generator-motor coincides with a generated voltage command and a control output of a generated torque control section (307) for controlling, based on the B-terminal voltage and a rotation speed, the field current so that generated torque of the polyphase AC generator-motor coincides with a generated torque command.