Multi-Phase PM Rotor Motor Voltage Tuning for Coil Current Balance
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Solution Overview
Problem
Existing multi-phase permanent magnet rotor motors face inefficiencies due to imbalances in stator coil parameters such as resistance and inductance, leading to torque imbalances and reduced efficiency.
Innovation Solution
A method involving pulse modulated control signals is applied to adjust motor control voltages and stator currents to equalize phase coil currents, using a modified field-oriented control system to ensure balanced torque distribution among stator coils.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If all phase coils are assumed to be identical with same resistance and inductance values, then the control system is simple, but torque imbalances occur due to manufacturing variations and wear
Solution Approach 1:
The patent applies parameter changes by adjusting the amplitude of motor control voltages for each phase coil based on measured current imbalances. The controller modifies voltage parameters dynamically to compensate for differences in coil resistance and inductance, thereby achieving balanced torque distribution despite manufacturing variations and wear.
2Productivity
If phase coil current imbalances are not corrected, then the control method is simple, but motor efficiency is reduced due to torque imbalances
Solution Approach 1:
The patent implements feedback control by measuring the current in each phase coil and using this information to adjust the motor control voltages. The controller continuously monitors current imbalances and modifies voltage amplitudes accordingly, creating a closed-loop system that eliminates torque imbalances and improves motor efficiency.
3Reliability
If individual phase coil adjustments are implemented, then torque balance is improved, but the control system becomes more complex
Solution Approach 1:
The patent applies local quality by adjusting control parameters individually for each phase coil based on its specific characteristics. Instead of uniform control, the system tailors voltage amplitudes to each coil's resistance and inductance values, achieving localized optimization that results in overall torque balance.
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 enhances motor efficiency by reducing torque imbalances and maintaining consistent operation, even under varying load conditions.
Implementation Method 1
outputting pulse modulated control signals to the respective phase coils to bring the motor to a constant mode of operation
Implementation Method 2
A permanent magnet motor uses permanent magnets in the rotor to provide a constant magnetic flux
Implementation Method 3
If a permanent magnet or electromagnet is present in this rotating magnetic field, the magnet is magnetically locked with the rotating magnetic field
Data Source
AI summary
A method of driving a multi-phase permanent magnet rotor motor having a plurality of phase coils. The method comprises outputting pulse modulated control signals to the respective phase coils to bring the motor to a constant mode of operation. Once the motor is in its constant mode of operation, the method includes measuring phase coil currents and, for a selected phase coil, adjusting values of multi-phase stationary reference frame voltages for only remaining phase coils by one or more predetermined increments until the phase coil currents of the remaining phase coils equals the phase coil current of the selected phase coil or until the phase coil currents of the remaining phase coils fall with a predetermined range with respect to the phase coil current of the selected phase coil.