Apparatus for driving compressor of air conditioner and method for driving the same
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Solution Overview
Problem
Air conditioner compressor motors experience significant speed ripples due to non-linear load torque variations, leading to inefficient operation and increased energy consumption.
Innovation Solution
A compressor driving apparatus and method that utilize a controller to detect and compensate for load torque by adjusting phase compensation angles and currents, minimizing speed ripples through sensorless algorithm-based control and optimal phase compensation patterns stored in tables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional motor driving devices are used to drive the compressor, then the compressor can operate, but significant speed ripples occur due to non-linear load torque variations
Solution Approach 1:
The controller continuously monitors the motor's phase currents and calculates instantaneous torque values. Based on the detected torque variations and speed ripple characteristics, the controller dynamically adjusts the phase compensation angles and current magnitudes to counteract the non-linear load torque, creating a closed-loop feedback system that maintains stable speed while optimizing energy consumption.
Solution Approach 2:
The invention changes the electrical parameters of the motor control system by introducing phase compensation angles (θa, θb, θc) that are optimized based on the detected torque characteristics. By varying these phase angles and current magnitudes in response to load conditions, the system compensates for torque ripples and speed variations without requiring additional mechanical components.
2Reliability
If torque control is applied to reduce speed ripple, then speed stability improves, but the control system complexity increases
Solution Approach 1:
The motor control system performs self-diagnosis and self-compensation by using its own phase current sensors to detect torque variations. The controller automatically calculates the compensation parameters and adjusts the motor drive without requiring external sensors or manual intervention, making the system self-sufficient while maintaining simple architecture.
Solution Approach 2:
The invention replaces complex mechanical torque measurement devices and speed sensors with an electrical-based torque detection method that uses existing phase current sensors. By calculating torque from electrical parameters rather than mechanical measurements, the system achieves accurate torque control while eliminating the need for additional mechanical components and simplifying the overall control architecture.
3Use of energy by moving object
If phase compensation is used to minimize speed ripple, then motor efficiency improves, but the precision of phase angle control must be high
Solution Approach 1:
The system performs preliminary torque detection and analysis during motor operation to establish the compensation parameters before applying phase correction. By pre-calculating the optimal phase angles based on detected torque characteristics and storing these compensation patterns, the system reduces the real-time computational burden and minimizes the precision requirements for instantaneous phase angle control.
Data Source
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AI summary
An apparatus and method for driving a compressor of an air conditioner are disclosed. When compensating for load torque of a compressor (e.g., a single-rotary compressor) of an air conditioner, a method for providing a compensation torque using an optimum phase compensation angle is used. In relation to a phase current or a frequency of a given motor, an optimum phase compensation angle causing a minimum speed ripple is measured, and the measured optimum phase compensation angle is stored in the form of a table. In the actual driving of the motor, the method applies a compensation torque having an optimum phase compensation angle to the motor by referring to the table.