Single Inverter Control for Multiple Permanent Magnet Motors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems require multiple inverters to control multiple permanent magnet motors, which increases complexity and costs, as the driving voltage needs to consider the rotating speed, output torque, and rotor location of each motor.
Innovation Solution
A power apparatus and method that uses a single inverter to control two or more permanent magnet motors by employing a controller that adjusts the driving voltage and current based on the rotating speed and location of each motor, allowing for synchronized operation and torque adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple inverters are used to control multiple permanent magnet motors, then each motor can be controlled independently with optimal performance, but the system complexity and cost increase
Solution Approach 1:
The patent merges multiple independent inverter systems into a single shared inverter that controls multiple permanent magnet motors. The controller within this single inverter is configured to independently control each motor by processing feedback signals from all motors and generating appropriate drive signals, thereby reducing the total number of inverters while maintaining independent control capability for each motor.
Solution Approach 2:
The single inverter controller is designed with multi-functional capability to handle control tasks for multiple different motors simultaneously. It can process feedback from various motors with different parameters and generate customized drive signals for each, making the single inverter serve multiple purposes that would traditionally require separate dedicated inverters.
2Device complexity
If a single inverter controls multiple permanent magnet motors, then system complexity and cost are reduced, but control precision and performance may deteriorate
Solution Approach 1:
The controller internally segments the control process for each motor, treating each motor's control as an independent task. It separately processes feedback signals from each motor, calculates required drive parameters individually, and generates dedicated drive signals for each motor phase, ensuring that control precision is maintained despite the shared hardware platform.
Solution Approach 2:
The controller dynamically adjusts control parameters such as switching frequencies, pulse width modulation duty cycles, and current limits based on the specific requirements of each motor and their operating conditions. This parameter adaptation enables precise control of each motor while sharing the same inverter hardware.
3Power
If driving voltage is adjusted for each motor based on rotating speed and torque, then optimal motor performance is achieved, but the control system complexity increases
Solution Approach 1:
The controller implements feedback control by receiving feedback signals from all controlled motors, processing these signals to determine actual operating conditions, and adjusting drive signals accordingly. This closed-loop feedback mechanism enables dynamic optimization of each motor's performance while consolidating control functions in a single inverter system.
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 control of multiple motors with a single inverter, reducing complexity and costs while maintaining optimal performance and minimizing power losses by dynamically adjusting the d-axis current and q-axis voltage.
Implementation Method 1
a permanent magnet motor using a permanent magnet rotates a rotor using a magnetic interaction between a magnetic field of a coil through which an electric current flows and a magnetic field of the permanent magnet
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed herein is a power apparatus including a first motor, a second motor connected with the first motor in parallel, a driver configured to supply driving currents to the first and second motors, a current detector configured to detect the driving current of the first motor and the driving current of the second motor, a speed calculator configured to calculate a rotating speed of the first motor and a rotating speed of the second motor, and a controller configured to control the driver based on the rotating speed of the first motor, wherein the controller controls the driver so that the rotating speed of the first motor and the rotating speed of the second motor are the same as each other, when the rotating speed of the first motor and the rotating speed of the second motor are different from each other.