Motor Driving Device Active Freewheel Voltage Boosting
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Solution Overview
Problem
Existing motor driving devices for starter motors/generators require additional large-scale devices like voltage step-up/step-down circuits or motor speed increasing mechanisms, leading to increased size, weight, and cost.
Innovation Solution
A motor driving device with a driving unit and controller that performs on/off control of switching elements in a bridge circuit to directly drive a starter motor/generator connected to an engine, allowing for active freewheel operation to boost regenerative voltage, controlled via a single PWM signal based on battery voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a voltage step-up/step-down circuit or motor speed increasing mechanism is added to charge regenerative power to a battery, then the regenerative power generation function is improved, but the device size, weight, and cost increase
Solution Approach 1:
The patent combines the voltage step-up/step-down circuit and motor speed increasing mechanism functions into the existing bridge circuit by utilizing active freewheel operations. This merging eliminates the need for separate additional devices, thereby reducing device size and weight while maintaining the regenerative power generation function.
Solution Approach 2:
The bridge circuit is designed to perform multiple functions: motor driving, voltage stepping up/down, and regenerative power generation. By making the bridge circuit universal, the patent eliminates the need for dedicated additional devices, thus reducing overall device weight and complexity while achieving effective regenerative charging.
2Use of energy by moving object
If a voltage step-up/step-down circuit or motor speed increasing mechanism is added to charge regenerative power to a battery, then the regenerative power generation function is improved, but the device complexity increases
Solution Approach 1:
The patent merges the voltage control and regenerative power generation functions into the existing bridge circuit control logic. By combining these functions, the patent reduces device complexity as fewer separate components and control systems are needed, while still achieving effective regenerative charging.
Solution Approach 2:
The bridge circuit is designed to universally handle motor driving, voltage regulation, and regenerative power generation through a single control system. This multi-functionality reduces device complexity by eliminating the need for multiple dedicated circuits and control mechanisms.
3Use of energy by moving object
If a voltage step-up/step-down circuit or motor speed increasing mechanism is added to charge regenerative power to a battery, then the regenerative power generation function is improved, but the cost increases
Solution Approach 1:
The patent combines the voltage step-up/step-down and regenerative power generation functions into the existing bridge circuit, eliminating the need for additional expensive components. This merging reduces manufacturing cost while maintaining full regenerative power generation capability.
Solution Approach 2:
The bridge circuit is designed to universally perform motor driving and regenerative power generation functions. This multi-functionality reduces the bill of materials and assembly requirements, thereby reducing manufacturing cost while achieving effective regenerative charging.
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 cost-effective control of motor driving voltage and regenerative voltage boosting without additional circuitry, reducing device size and weight while maintaining effective engine assistance and charging operations.
Implementation Method 1
turns on predetermined switching elements of the bridge circuit at a predetermined timing to perform an active freewheel operation for boosting a regenerative voltage generated by the starter motor/generator
Implementation Method 2
The driving unit controls a motor driving voltage for the starter motor/generator by changing ON periods of the switching elements of the bridge circuit
Data Source
AI summary
A motor driving device is provided. The motor driving device includes a driving unit configured to drive a starter motor/generator that is directly connected to an engine by a rotation shaft, by performing on/off control of switching elements in a bridge circuit for driving a motor; and a driving controller configured to control a driving operation for the starter motor/generator that is performed by the driving unit. The driving unit controls a motor driving voltage for the starter motor/generator by changing ON periods of the switching elements of the bridge circuit, and turns on predetermined switching elements of the bridge circuit at a predetermined timing to perform an active freewheel operation for boosting a regenerative voltage generated by the starter motor/generator. The driving controller instructs the driving unit to control the motor driving voltage and on/off of the active freewheel operation, based on a battery voltage.