Vehicle Power Source Controller Voltage Step-Up for Sensor Failure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric vehicles face issues with maintaining normal operation when the target operating point of an electric motor cannot be properly detected, leading to potential regenerative braking and controllability deterioration due to insufficient step-up voltage.
Innovation Solution
A power source apparatus for vehicles that includes a voltage converting unit and a controller, which steps up the voltage of an electric storage device and sets the target step-up voltage to the highest settable value if the operation state signal is abnormal, ensuring continued operation without relying on the faulty signal, and uses sensors to determine abnormal conditions such as rotation speed and current deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the target operating point is detected using normal sensors and control methods, then the voltage can be stepped up appropriately for normal motor operation, but when the operating point cannot be properly detected, the output voltage becomes lower than back electromotive voltage causing regenerative braking and controllability deterioration
Solution Approach 1:
The controller proactively determines a default target operating point (zero torque command and zero rotation speed) when abnormality is detected, before the system fails. This preliminary action prevents the voltage output from dropping below back electromotive voltage and avoids regenerative braking, ensuring continuous reliable operation despite loss of accurate operating point information
Solution Approach 2:
The controller changes the control parameters by setting default values for torque command and rotation speed when sensor abnormality is detected. This parameter change allows the system to maintain a valid target operating point even when normal detection fails, preventing voltage collapse and maintaining motor controllability
2Ease of operation
If the controller uses the operation state signal to determine target step-up voltage, then normal voltage control is achieved, but when the signal is abnormal, the voltage becomes insufficient and motor operation fails
Solution Approach 1:
The controller implements a feedback mechanism that continuously monitors the operation state signal for abnormalities. When abnormality is detected, the feedback loop switches to using default target operating point values, ensuring that the target step-up voltage determination remains reliable even when the normal feedback signal fails
Solution Approach 2:
The controller prepares default target operating point values in advance as a cushion against signal failure. This beforehand cushioning ensures that when the operation state signal becomes abnormal, the system immediately has valid backup values to maintain voltage control, preventing operation failure
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
This solution maintains normal vehicle operation by ensuring the step-up voltage is sufficient, preventing regenerative braking and controllability issues even when the target operating point is not properly detected, by increasing the voltage to the maximum value when abnormal conditions are detected.
Implementation Method 1
a voltage converting unit stepping up a voltage of the electric storage device and supplying the stepped-up voltage to the inverter
Data Source
AI summary
A vehicle (100) includes a motor generator (MG) and an inverter (14) driving the motor generator (MG). A power source apparatus for the vehicle includes a battery (B) as an electric storage device, a step-up converter (12) stepping up a voltage of the electric storage device and supplying it to the inverter, and a controller (30) indicating a target step-up voltage in accordance with a target state of operation of the motor generator (MG) to the step-up converter (12). If it is determined that a current operation state signal of the motor generator (MG) is abnormal, the controller (30) increases the target step-up voltage to a maximum value. Preferably, the vehicle (100) further includes a resolver (20) detecting rotation speed of a rotor of motor generator (MG). The controller (30) determines that the operation state signal is abnormal if an output of the resolver (20) does not satisfy a prescribed condition.