Neutral Point Voltage Control for EV Regenerative Braking
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Solution Overview
Problem
Existing regenerative braking systems in electric vehicles cannot effectively control the amount of power consumption by electric loads during surplus power generation, leading to potential battery damage and inefficient energy usage.
Innovation Solution
A power control apparatus featuring two star-connected poly-phase AC electric motors, an electric storage system, and a voltage control unit that calculates and controls the voltage across neutral points to manage surplus power consumption by an electric load, ensuring optimal power usage without excessive or insufficient consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If surplus power is consumed by electric loads in accordance with the magnitude of surplus power, then the surplus power can be used up effectively, but it becomes impossible to successively control the amount of power consumption by the electric loads
Solution Approach 1:
The patent applies dynamics by making the voltage across neutral points dynamically adjustable based on the magnitude of surplus power. The voltage control unit continuously modifies the voltage level to match the surplus power condition, enabling successive control of power consumption while effectively utilizing surplus energy. This dynamic adjustment resolves the contradiction by allowing both effective surplus power usage and controllable power consumption.
2Ease of operation
If the voltage across neutral points is controlled in accordance with surplus power, then the amount of power consumption can be controlled successively, but complex control mechanisms are required
Solution Approach 1:
The patent introduces a voltage control unit as an intermediary between the power system and electric loads. This intermediary component simplifies the control architecture by centralizing the voltage adjustment function, making successive control of power consumption achievable without requiring complex distributed control mechanisms across multiple components.
3Device complexity
If electric loads are simply combined according to surplus power magnitude, then the structure remains simple, but sufficient surplus power utilization cannot be achieved
Solution Approach 1:
The patent applies parameter changes by modifying the voltage parameter across neutral points according to the magnitude of surplus power. Instead of simply combining electric loads, the system adjusts the voltage level to optimize power consumption, thereby achieving effective surplus power utilization while maintaining relatively simple system structure through a single control parameter adjustment.
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 allows for successive control of power consumption by the electric load, preventing battery damage and ensuring efficient use of surplus power, thereby optimizing energy management during regenerative braking.
Implementation Method 1
at the time of regenerative braking of a vehicle, the motor is rotated by the rotating force from the driving wheel to regenerate power
Implementation Method 2
a voltage across first and second neutral points is controlled in accordance with the calculated surplus power, the generated surplus power is consumed by the electric load
Data Source
AI summary
When surplus power not charged to an electric storage is generated at the time of regenerative braking of a vehicle, a voltage is generated across first and second neutral points using a zero-voltage vector each of first and second inverters and the generated surplus power is consumed by a resistance connected across the first and second neutral points. The voltage generated across the first and second neutral points is calculated in accordance with the surplus voltage, using a resistance value of the resistance.