Dual-Motor Inverter Phase Sequencing for Opposed Shaft Rotation
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Solution Overview
Problem
In electric vehicles with two electric motors connected to the same output shaft facing each other, existing systems struggle to coordinate the rotation direction of the motors to prevent torque cancellation or damage, as both motors attempting to rotate in the same direction can cause the vehicle to malfunction or suffer damage.
Innovation Solution
A method and system where configurable inverters determine the position of each electric motor relative to the other and adjust their three-phase AC output accordingly, ensuring that one motor rotates clockwise while the other rotates counterclockwise, using a controller and power circuit to modify the output based on motor position inputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If both electric motors are connected to the same output shaft facing each other, then the vehicle can utilize multiple motors for propulsion, but the motors may rotate in the same direction causing torque cancellation or damage
Solution Approach 1:
The inverter controller receives feedback about the relative position of the two electric motors and uses this information to adjust the phase sequence of the AC output to each motor. This feedback mechanism ensures that the motors rotate in opposite directions as intended, preventing torque cancellation and ensuring reliable coordinated operation.
Solution Approach 2:
The system changes the electrical parameter (phase sequence) of the AC output from the inverter based on the detected motor position. By switching between different phase sequences (e.g., ABC vs ACB), the system controls the rotation direction of each motor to ensure they rotate in opposite directions, resolving the torque cancellation issue.
2Reliability
If the inverter output is adjusted based on motor position, then proper motor rotation coordination is achieved, but the system complexity increases
Solution Approach 1:
The system uses the motors' own position information (detected by sensors already present in the motors) to automatically adjust their own control parameters. Each motor's position feedback is used by the inverter controller to determine the appropriate phase sequence, making the system self-configuring without requiring external intervention or complex manual setup.
3Productivity
If the inverter selectively outputs three-phase AC to each motor based on position, then torque application efficiency is enhanced, but the control system becomes more complex
Solution Approach 1:
The inverter controller dynamically adjusts the phase sequence assignment to each motor based on real-time position information. This dynamic adaptation allows the system to optimize torque application efficiency for different motor positions and operational conditions, while the computational complexity is managed through algorithmic control rather than additional hardware.
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
Prevents torque cancellation and ensures proper vehicle movement by accurately coordinating the rotation of electric motors, reducing the risk of damage and enhancing the efficiency of torque application to the output shaft.
Implementation Method 1
A power inverter, sometimes referred to as an inverter, is a power electronic device or circuit that changes one type of current, such as direct-current (DC), to another type of current, such as alternating current (AC).
Implementation Method 2
The operation of the three switches is coordinated by a controller so that one switch operates at each 60-degree point of the fundamental output waveform. This creates a line-to-line output waveform that has six steps. The six-step waveform has a zero-voltage step between the positive and negative sections of the square wave such that the harmonics that are multiples of three are eliminated.
Data Source
AI summary
Disclosed are systems, methods, and devices for configuring the output provided by an inverter to an electric motor based on the position of the electric motor with respect to another electric motor.