Air Conditioner Motor Control for Constant-Speed Ripple Reduction
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Solution Overview
Problem
Air conditioner motor driving systems experience significant speed ripple during constant speed operations, which affects the efficiency and stability of compressor and fan operations, and existing solutions fail to accurately calculate optimal load patterns and maximum mechanical angles to mitigate this issue.
Innovation Solution
A motor driving apparatus and method that includes a controller to detect mechanical angles, calculate maximum speed mechanical angles, and compensate for load torque using a sensorless algorithm, thereby reducing speed ripple by selecting an optimum load pattern table and adjusting switching operations to minimize speed fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the motor is driven at a constant speed using conventional control methods, then the motor operates steadily, but significant speed ripple occurs affecting compressor and fan performance
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the mechanical angle detection range and load torque compensation values based on operating conditions. The controller modifies detection parameters and compensation amounts to optimize speed control and minimize ripple during constant speed operation.
Solution Approach 2:
The patent implements feedback control by continuously detecting the mechanical angle, calculating speed ripple based on detected angles, and adjusting the load torque compensation accordingly. The system uses detected mechanical angle information to feedback control the motor driving, thereby reducing speed ripple.
2Stability of the object's composition
If existing solutions are used to mitigate speed ripple, then some reduction may be achieved, but optimal load patterns and maximum mechanical angles cannot be accurately calculated
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing optimal load patterns and maximum mechanical angles in lookup tables before actual operation. During constant speed operation, the controller directly references these pre-calculated values to achieve accurate speed control without real-time calculation complexity.
Solution Approach 2:
The patent replaces complex real-time mechanical angle and load pattern calculations with a sensorless algorithm that uses electrical measurements and pre-stored lookup tables. This substitution achieves equivalent or superior precision without the complexity of direct mechanical sensing and calculation.
3Stability of the object's composition
If mechanical angle detection is performed with high precision to reduce speed ripple, then speed control improves, but system complexity and computational burden increase
Solution Approach 1:
The patent applies self-service by using the motor's own electrical parameters and existing sensor data to determine mechanical angle and speed ripple. The system utilizes information already available from the motor driving process, eliminating the need for additional mechanical sensors or complex external detection systems.
Solution Approach 2:
The patent replaces mechanical angle detection systems with an electrical-based sensorless algorithm. Instead of using mechanical encoders or resolvers, the system calculates mechanical angle from electrical measurements and control parameters, significantly reducing system complexity while maintaining detection precision.
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 speed ripple during constant speed operations, improving the efficiency and stability of air conditioner compressor and fan operations by accurately calculating and compensating for load torque, leading to enhanced performance and reduced assembly errors.
Implementation Method 1
an inverter that includes a plurality of switching elements, outputs AC power having a predetermined frequency and a predetermined magnitude by a switching operation of the switching elements
Data Source
AI summary
An apparatus and method for driving a motor of an air conditioner are disclosed. A method for driving a motor of an air conditioner includes driving the motor in response to a predetermined speed command, sequentially detecting first and second mechanical angles in response to the speed command or a reference speed being spaced apart from the speed command by a predetermined range, calculating a maximum speed mechanical angle corresponding to a maximum speed ripple of the motor on the basis of the detected first and second mechanical angles, and compensating for load torque of the motor on the basis of the calculated the maximum speed mechanical angle. As a result, the speed ripple is decreased during the constant speed operation.