Eco Vehicle Charging System Rotor Positioning for Inverter Thermal Stability
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Solution Overview
Problem
Eco-friendly vehicle charging systems face durability issues due to temperature fluctuations in power conversion devices of inverters caused by uneven inductance of motor phases, leading to increased current ripple and losses.
Innovation Solution
A charging system for eco-friendly vehicles that moves the rotor of a motor to a predetermined reference position before charging, balancing inductances and maintaining constant temperature of power conversion devices, using a motor-inverter charging unit with a controller, relays, and position detector to manage power supply and charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If charging is performed without moving the rotor to a reference position, then charging speed is maintained, but temperature of power conversion devices fluctuates due to uneven inductance
Solution Approach 1:
The rotor is moved to a predetermined reference position before the charging operation begins. This preliminary positioning ensures that the inductance of all phases is balanced at the start of charging, preventing temperature fluctuations in the power conversion devices during the charging process.
2Reliability
If rotor position is adjusted to balance inductance, then temperature stability improves, but system complexity increases
Solution Approach 1:
The system uses the motor's own rotor positioning capability to balance the inductance phases. The controller utilizes the existing motor structure and its control system to automatically position the rotor at the reference position, eliminating the need for external mechanical positioning devices or additional balancing components.
3Loss of energy
If rotor is repositioned before charging, then current ripple is reduced, but energy loss during positioning occurs
Solution Approach 1:
The system changes the operational parameter of the motor from normal driving mode to a positioning mode. By controlling the motor to operate in a controlled stopping state at a specific position (reference position), the inductance parameters are optimized for charging, reducing current ripple and subsequent energy losses during 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
This approach stabilizes the temperature of power conversion devices, enhancing the durability of the inverter by minimizing current imbalance and temperature differences, thus improving overall system performance.
Implementation Method 1
the inductance of the phases of the motor is changed by the position of the rotor of the motor
Data Source
AI summary
A charging system for an eco-friendly vehicle is provided. The system includes a power supply unit that provides power for charging an automotive battery and a charging unit including a motor and an inverter connected with the motor, and that charges the battery by being supplied with power from the power supply unit. One or more relays connect the power supply unit and the battery to each other and a controller moves a rotor of the motor to a predetermined reference position before charging the battery.