Independent Phase Windings for Sensorless PM Rotor Torque Control
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Solution Overview
Problem
Existing multi-phase permanent magnet rotor motors face challenges in maintaining accurate control of rotor position and achieving maximum constant torque using sensorless motor control systems.
Innovation Solution
A multi-phase permanent magnet rotor motor with independent phase coil windings and a controller comprising full-bridge inverters that output pulse modulated control signals, including sine waves and full-bridge space vector modulation signals, with current sense circuits connected to only one half of each full-bridge inverter to improve rotor position estimation and torque control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If sensorless motor control systems are used to eliminate sensors, then device complexity and cost are reduced, but rotor position estimation accuracy deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where current signals from the motor phases are continuously monitored and fed back to the controller. The controller uses these current signals to estimate rotor position and speed, creating a closed-loop sensorless control system that maintains accuracy without physical sensors.
Solution Approach 2:
The patent replaces the mechanical sensor system (Hall sensors or encoders) with an electronic estimation system. The controller electronically calculates rotor position and speed by analyzing back-EMF and current signals, substituting physical sensing components with computational methods.
2Device complexity
If traditional motor winding configurations are used, then device complexity is reduced, but torque output and efficiency deteriorate
Solution Approach 1:
The patent segments the motor windings into independent phase coil windings without a common neutral point. Each phase winding is independently controlled by dedicated full-bridge inverters, allowing optimized current distribution and magnetic field generation that increases torque output compared to traditional star or delta configurations.
Solution Approach 2:
The patent employs dynamic control of the independent phase windings through pulse-modulated signals from full-bridge inverters. The system dynamically adjusts the switching states of the inverters to optimize torque production across different operating conditions, enabling maximum constant torque capability.
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 configuration enhances rotor position estimation and achieves 15% more constant torque compared to traditional motor winding configurations by applying sine wave signals in one range and full-bridge space vector modulation signals in another, improving motor efficiency and control accuracy.
Implementation Method 1
the magnet is magnetically locked with the rotating magnetic field and consequently rotates at the same speed as the rotating field
Implementation Method 2
an electrical field is generated. The rotating magnetic field rotates at a certain speed known as the synchronous speed
Implementation Method 3
A permanent magnet motor uses permanent magnets in the rotor to provide a constant magnetic flux which has a sinusoidal back-electromotive force (emf) signal
Data Source
AI summary
A multi-phase permanent magnet rotor motor comprises a plurality of phase coil windings with each phase coil winding having two free ends and the plurality of phase coil windings being without a common node. A controller is provided comprising a plurality of full-bridge inverters. Each full-bridge inverter has two output ends electrically connected to the two free ends of a corresponding phase coil winding. The controller is configured to operate the plurality of full-bridge inverters to output pulse modulated control signals to their respective phase coil windings. The outputted pulse modulated control signals can comprise a combination of sine wave signals and full-bridge space vector modulation signals.