Compressor Torque Compensation Using Phase Locked Loop

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Solution Overview

Problem

Current compressor torque compensation technologies face challenges in tracking load torque angle and amplitude in real-time, leading to inefficient debugging and potential over- or under-compensation, resulting in significant vibrations during low-frequency operation.

Innovation Solution

A method and apparatus for automatic torque compensation using a phase locked loop (PLL) to generate a torque compensation angle and amplitude, allowing real-time adjustment and tracking of load torque, reducing debugging time and optimizing compensation effects across all working conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a common sine torque compensation is used with fixed angle and amplitude values, then the debugging process is simplified, but the compensation effect deteriorates due to inability to track real-time load changes

Engineering Contradiction:
Improvedebugging simplicityVSAvoidcompensation accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent transforms the static torque compensation method into a dynamic one by using a phase-locked loop to continuously track the load torque angle and amplitude in real-time. The compensation angle θ and amplitude M are no longer fixed values but dynamically adjusted parameters that adapt to changing load conditions, thereby resolving the contradiction between debugging simplicity and compensation accuracy.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements a feedback mechanism where the actual load torque information is continuously monitored and fed back to the control system. The phase-locked loop compares the actual load torque angle and amplitude with the compensation parameters, and automatically adjusts the compensation values to match the real-time load conditions, ensuring accurate compensation without requiring extensive manual debugging.

Inventive Principle:
Principle #23Feedback

2Reliability

If the torque compensation parameters are adjusted in real-time to track load changes, then the compensation accuracy is improved, but the system complexity increases

Engineering Contradiction:
Improvecompensation accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a phase-locked loop as an intermediary component that simplifies the complex task of real-time parameter tracking. The PLL acts as a mediator between the load torque sensor and the torque compensation generator, automatically extracting the load torque angle and amplitude through phase comparison and amplitude detection, thereby reducing the overall system complexity while maintaining high compensation accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a fixed torque compensation value is used for all operating conditions, then the control system is simplified, but vibration increases due to over-compensation or under-compensation

Engineering Contradiction:
Improvecontrol system simplicityVSAvoidvibration
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the compensation parameters (angle θ and amplitude M) dynamically based on operating conditions. Instead of using a fixed compensation value, the system continuously adjusts these parameters according to the real-time load torque characteristics detected by the phase-locked loop. This ensures that the compensation always matches the actual load requirements, preventing both over-compensation and under-compensation that would otherwise cause vibration.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If the debugging process searches for optimal angle and amplitude values, then the compensation accuracy is improved, but the debugging time and energy consumption increase significantly

Engineering Contradiction:
Improvecompensation accuracyVSAvoiddebugging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent enables the system to automatically determine and adjust its own compensation parameters without requiring extensive manual debugging. The phase-locked loop continuously self-adjusts the compensation angle and amplitude by tracking the load torque characteristics in real-time. This self-service capability eliminates the need for time-consuming manual optimization processes while maintaining high compensation accuracy throughout the operating range.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3098449B1Method and device for automatically compensating for moment of compressor, compressor, and control method for same
Publication Date: 2020.12.23 GUANGDONG MEIZHI COMPRESSOR
  • EP3098449B1 patent drawingFigure 1
  • EP3098449B1 patent drawingFigure 2
  • EP3098449B1 patent drawingFigure 3

AI summary

A method for an automatic torque compensation of a compressor is provided. The method includes: obtaining a target speed and a feedback speed; generating a fluctuation speed according to the target speed and the feedback speed; generating a torque compensation angle according to the target speed and the fluctuation speed in a phase locked loop (PLL) manner; obtaining a load torque reference value and generating a torque compensation amplitude according to the load torque reference value; and generating a feedforward torque compensation value according to the target speed, the torque compensation angle and the torque compensation amplitude. A method for controlling a compressor, an apparatus for an automatic torque compensation of a compressor and a compressor including the apparatus are also provided.