Multiphase Motor Controller Torque Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiphase rotating electric machines face inefficiencies in torque output when switching from a two-system driving mode to a one-system driving mode, as the optimal current phase and amplitude differ significantly, leading to reduced total torque output in the one-system mode.
Innovation Solution
A controller that adjusts the maximum amplitude and current phase of the alternating current in the one-system driving mode to compensate for the loss in reluctance torque, allowing for efficient torque output by switching between torque-d-axis current and torque-q-axis current maps in both driving modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller switches from two-system driving mode to one-system driving mode, then the system reliability is improved by continuing operation, but the total torque output deteriorates to less than half of the two-system mode
Solution Approach 1:
The controller changes the current amplitude and current phase parameters when switching from two-system to one-system driving mode. Specifically, it increases the current amplitude to greater than 50% of the two-system mode and adjusts the current phase to optimize the dq-axis current ratio, thereby compensating for the loss of reluctance torque and maintaining higher total torque output.
2Ease of operation
If the controller uses the optimal current phase from two-system driving mode in one-system driving mode, then the control simplicity is maintained, but the torque generation efficiency deteriorates due to suboptimal current phase
Solution Approach 1:
The controller dynamically adjusts the current phase and dq-axis current ratio based on the operating mode. It switches between different control strategies: using the optimal current phase from two-system mode when both systems operate, and adjusting to an optimized current phase with increased amplitude when operating in one-system mode, thereby maximizing torque generation efficiency in each mode.
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 torque output in both two-system and one-system driving modes by optimizing current amplitude and phase, maintaining 50% of the output torque in the one-system mode compared to the two-system mode, ensuring consistent assist force in electric power steering systems.
Implementation Method 1
a first power converter configured to supply an alternating current to a first set of windings, a second power converter configured to supply an alternating current to a second set of windings
Implementation Method 2
when a d-axis inductance and a q-axis inductance are different from each other in a magnet-embedded-type rotating electric machine, a reluctance torque is generated based on the difference of the two inductances
Data Source
AI summary
A controller of a multiphase rotating electric machine has two inverters outputting an alternating current to two sets of windings, and a control section driving a motor by switching between a “two-system driving mode” supplying power from the two inverters to the two sets of winding and a “one-system driving mode” supplying power from one of the two inverters to the corresponding set of windings, The control section in the one-system driving mode changes at least one of a maximum amplitude and a current phase of the alternating current used in the two-system driving mode to compensate for a reluctance torque generated by a mutual inductance of the two sets of winding in the two-system driving mode.