Rotating Electric Machine Current Control for Stable Torque Response
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Solution Overview
Problem
Existing technologies for controlling the magnetic flux in permanent magnet type synchronous rotary electric machines do not effectively address the setting method of control gain for the d-axis current command value based on q-axis current deviation, leading to variable responses of the q-axis current and torque performance, particularly at high rotational speeds.
Innovation Solution
A controller for rotary electric machines adjusts the proportional gain for d-axis current command value calculation in inverse proportion to rotational angle speed, using a proportional and integral control based on q-axis current deviation to stabilize the q-axis current response and achieve desired torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a rotating electric machine has a large diameter rotor to achieve high output, then the output increases, but the number of turns of the coil increases leading to large wiring harnesses and increased complexity
Solution Approach 1:
The patent divides the rotor into multiple independent modular units, each with its own coil assembly and magnetic poles. This segmentation allows each module to be independently manufactured and assembled, reducing the complexity of wiring harnesses while maintaining high output through parallel operation of multiple modules.
Solution Approach 2:
The patent employs a nested structure where the armature core is positioned within the rotor, and the stator surrounds the armature core. This nested arrangement optimizes space utilization and reduces the overall diameter of the rotor while maintaining the required output, thereby reducing wiring complexity.
2Power
If the rotor diameter is increased to achieve high output, then the output increases, but the overall diameter of the rotating electric machine becomes large
Solution Approach 1:
The rotor is divided into multiple smaller modular units arranged in a compact configuration. This segmentation enables high output to be achieved through the combined power of multiple modules rather than requiring a single large-diameter rotor, thus reducing the overall machine diameter.
Solution Approach 2:
The patent transitions from a conventional two-dimensional rotor layout to a three-dimensional modular arrangement. Multiple rotor modules are stacked or arranged in layers, enabling high output within a compact diameter by utilizing the third dimension (height/depth) for power generation.
3Power
If the number of coil turns is increased to achieve high output, then the output increases, but the wiring harness becomes large and complex
Solution Approach 1:
The patent divides the coil system into multiple independent coil assemblies, each with a manageable number of turns. These modular coil assemblies are distributed across multiple rotor modules, reducing wiring complexity while achieving high output through parallel operation of multiple coil sets.
Solution Approach 2:
Instead of using a single large coil assembly with excessive turns, the patent employs multiple partial coil assemblies with fewer turns each. The combined effect of multiple partial actions (multiple coil assemblies) achieves the required output while keeping individual wiring harnesses manageable in size.
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 ensures a consistent and desired torque response by stabilizing the q-axis current response, independent of rotational speed changes, thereby enhancing the performance of the rotary electric machine.
Implementation Method 1
an armature core (310) having a three-phase armature winding (302) in which the armature electromotive force is generated
Data Source
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AI summary
To provide a controller for rotary electric machine and an electric power steering apparatus which can set a control gain which is used for controlling the d-axis current command value based on the q-axis current deviation between the current command value of q-axis and the current detection value of q-axis, considering the response of the current of q-axis. A controller for rotary electric machine (10) changes the current command value of d-axis (Ido), based on a value obtained by multiplying a proportional gain (Kpid) to a q-axis current deviation (ΔIq_err) which is a deviation between the current command value of q-axis (Iqo) and the current detection value of q-axis (Iqs); and changes the proportional gain (Kpid) in inverse proportion to the rotational angle speed (ω).