Electric Brake Control to Prevent Multiphase Motor Overheating
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Solution Overview
Problem
Existing vehicle braking systems with multiphase motors face issues of uneven heating due to current concentration in specific phases when maintaining braking force, which can lead to inefficiencies and potential damage.
Innovation Solution
A vehicle braking apparatus with a braking force controller that executes an 'up-down' process, varying the braking force command values using sine or rectangular/trapezoidal waves to distribute current evenly across phases, preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If braking force is maintained using multiphase motors, then braking force is provided, but current concentrates in specific phases causing uneven heating
Solution Approach 1:
The patent applies periodic action by executing an up-down process that periodically increases and decreases the braking force command value. This periodic variation causes the motor to cyclically adjust its operating phases, preventing current from continuously concentrating in specific phases and thereby reducing uneven heating while maintaining the required braking force.
Solution Approach 2:
The patent employs parameter changes by dynamically adjusting the braking force command value as a control parameter. By varying this parameter in an up-down manner, the control system changes the motor's operating state, which redistributes current across different phases over time and prevents thermal concentration in specific phases.
2Temperature
If braking force command value is varied using up-down process, then current is distributed evenly across phases, but braking force fluctuates
Solution Approach 1:
The patent implements feedback by continuously monitoring the braking force and using this information to adjust the braking force command value. The feedback mechanism ensures that while the up-down process varies the command value to distribute current evenly, the actual braking force remains stable by compensating for fluctuations based on real-time system response.
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 solution effectively prevents uneven heating in multiphase motors by evenly distributing current, maintaining braking force, and reducing thermal stress on the system.
Implementation Method 1
A vehicle braking apparatus may exert braking force by motor energization
Implementation Method 2
Existing vehicle braking systems with multiphase motors face issues of uneven heating due to current concentration in specific phases
Data Source
AI summary
A vehicle braking apparatus is adapted to a vehicle in which electric brakes are separately provided for wheels, and the electric brakes separately exert braking forces on the wheels. A braking force controller controls the braking forces separately exerted by the electric brakes. A first pair of electric brakes are provided for a front-left wheel and a front-right wheel, and a second pair of electric brakes are provided for a rear-left wheel and a rear-right wheel. At least one of the first pair of electric brakes or the second pair of electric brakes are multiphase electric brakes, and each of the multiphase electric brakes includes a multiphase motor having three or more phases. The braking force controller executes an up-down process to prevent a current from being concentrated on a particular phase of the multiphase motor, except when the vehicle satisfies a predetermined exemption condition.