Motor control apparatus, motor, compressor, refrigeration apparatus and vehicle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control systems fail to effectively reduce harmonic components in power input and electromagnetic exciting force, leading to torque ripple and energy inefficiencies, despite efforts to minimize harmonic components in the power input.
Innovation Solution
A motor control apparatus that suppresses the amplitude of first and second harmonic components by adjusting the modulation rate, voltage vector amplitude and phase, and current vector amplitude and phase, using a control unit to determine compensation values based on harmonic relationships, ensuring the amplitude of the electromagnetic exciting force harmonic is lower than the power input harmonic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a harmonic component is reduced in power input into the motor, then power quality is improved, but harmonic components in electromagnetic exciting force and torque ripple cannot be effectively reduced
Solution Approach 1:
The invention changes the control parameters by introducing a compensation current that specifically targets the harmonic components in the electromagnetic exciting force. By adjusting the amplitude and phase of this compensation current based on motor rotation speed, the system can independently control the harmonic content in power input separate from the harmonic content in electromagnetic exciting force, thereby resolving the contradiction between improving power quality and reducing torque ripple.
Solution Approach 2:
The invention introduces a compensation current as an intermediary element that acts between the power input and the electromagnetic exciting force. This compensation current is designed to specifically counteract the harmonic components causing torque ripple while maintaining the overall power quality improvements, thus serving as a mediator that addresses both concerns simultaneously.
2Loss of energy
If conventional harmonic reduction control is applied, then power input harmonics are reduced, but electromagnetic exciting force harmonics remain unaffected
Solution Approach 1:
The invention modifies the control parameters by adding a compensation current with specific amplitude and phase characteristics that are functions of motor rotation speed. This allows the system to independently adjust the harmonic content in electromagnetic exciting force without affecting the power input harmonic reduction already achieved, thereby improving electromagnetic exciting force stability while maintaining power quality.
Solution Approach 2:
The invention applies preliminary action by pre-calculating and applying compensation current based on anticipated harmonic issues at different rotation speeds. The control unit determines appropriate compensation amounts in advance based on the relationship between rotation speed and harmonic characteristics, preventing electromagnetic exciting force harmonics before they occur rather than reacting to them afterward.
3Loss of energy
If simple power harmonic reduction is implemented, then input power quality improves, but comprehensive harmonic suppression in both power and electromagnetic force is not achieved
Solution Approach 1:
The invention extends parameter control by introducing additional controllable parameters (compensation current amplitude and phase) that are dynamically adjusted based on motor rotation speed. This allows the relatively simple power harmonic reduction control to be enhanced with minimal additional complexity, achieving comprehensive harmonic suppression in both power input and electromagnetic exciting force through systematic parameter management.
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
The solution effectively reduces harmonic components in both power input and electromagnetic exciting force, improving energy efficiency and reducing torque ripple by aligning the energy storage and output variations.
Implementation Method 1
a motor control apparatus configured to convert an input power supplied from a power supply to an output alternating-current power having a predetermined voltage and a predetermined frequency
Implementation Method 2
perform a control to suppress an amplitude of a first harmonic component that occurs synchronously with a rotation rate of the motor in a power input into the motor and to suppress an amplitude of a second harmonic component that occurs in an electromagnetic exciting force of the motor
Data Source
AI summary
A motor control apparatus configured to convert an input power supplied from a power supply to an output alternating-current power having a predetermined voltage and a predetermined frequency is provided. The motor control apparatus includes an inverter circuit configured to supply the output alternating-current power to a motor, and is configured to perform a control to suppress an amplitude of a first harmonic component that occurs synchronously with a rotation rate of the motor in a power input into the motor to be lower than or equal to a predetermined value and to suppress an amplitude of a second harmonic component that occurs in an electromagnetic exciting force of the motor at a same frequency as the first harmonic component to be lower than the amplitude of the second harmonic component in a case of the amplitude of the first harmonic component being suppressed to a minimum.