Single Rotor Compressor Speed Control via Phase-Locked Loop Filtering
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Solution Overview
Problem
Single rotor compressors experience severe speed fluctuations due to unstable load torque, leading to unstable operation, excessive noise, and adverse effects on air conditioner performance, which existing control methods fail to adequately address.
Innovation Solution
A method that controls compressor speed by filtering shaft errors using Fourier series expansion and phase compensation, and compensating angular velocity outputs in a phase-locked loop to stabilize compressor operation, while also filtering angular velocity differences in the speed loop to reduce torque fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional control methods are used for single rotor compressor, then the control system is simple, but severe speed fluctuation occurs under unstable load torque
Solution Approach 1:
The patent implements a feedback mechanism by detecting actual compressor speed and comparing it with target speed to generate speed deviation signals. This feedback is used to dynamically adjust control parameters (Kp and Ki) in the PID controller, enabling the system to automatically compensate for speed fluctuations under unstable load conditions without requiring overly complex control architecture
Solution Approach 2:
The patent dynamically changes control parameters (proportional gain Kp and integral gain Ki) based on real-time speed deviation and its rate of change. By adaptively adjusting these parameters rather than using fixed values, the control system achieves better speed stability under varying load conditions while maintaining reasonable system complexity
2Object-affected harmful factors
If no speed fluctuation suppression is applied, then the control method is simple, but noise exceeds design threshold and relevant standards
Solution Approach 1:
The patent uses speed detection and feedback to continuously monitor compressor operation and identify speed fluctuations that generate noise. The feedback signal triggers compensatory control actions that suppress the fluctuations before they translate into excessive noise, effectively reducing noise without requiring complex passive damping structures
Solution Approach 2:
The patent applies preliminary anti-action by predicting speed fluctuations based on load torque variations and applying compensatory control in advance. The controller proactively adjusts motor output to counteract upcoming speed variations that would otherwise cause noise, rather than merely reacting after the noise-generating fluctuation occurs
3Reliability
If existing speed fluctuation suppression methods are used, then some speed control is achieved, but the problem of compressor speed fluctuation is not fundamentally solved
Solution Approach 1:
The patent fundamentally improves speed stability by dynamically changing control parameters based on real-time operating conditions. The adaptive adjustment of Kp and Ki gains ensures optimal control performance across different load scenarios, fundamentally solving the speed fluctuation problem rather than providing partial suppression
Solution Approach 2:
The patent replaces mechanical speed regulation mechanisms with an electronic control system that uses electrical signals to adjust motor performance. This substitution allows for more precise and responsive speed control, fundamentally addressing speed fluctuation issues that mechanical systems cannot adequately handle
Data Source
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AI summary
Disclosed is a method for controlling the rotational speed fluctuation of a single rotor compressor, comprising the process of controlling the compressor according to the real-time angle speed and the torque. The process of controlling the compressor according to the real-time angle speed comprises the following steps: performing filtering processing to the axis error to obtain an angle speed compensation dosage; compensating the angle speed compensation dosage to the output angle speed of the phase-locked loop regulator to obtain a compensated angle speed output quantity; correcting the real-time angle speed according to the compensated angle speed output quantity, and controlling the compressor according to the corrected real-time angle speed. The process of controlling the compressor according to the torque comprises the following steps: calculating the difference between a target angle speed fluctuating quantity and a feedback angle speed to obtain a first angle speed difference (21); performing filtering processing to the first angle speed difference to obtain a filter angle speed (22); inputting the filter angle speed into a speed ring regulator to obtain an output torque (23), and controlling the compressor according to the output torque (24). The method is able to improve the validity of inhibiting the rotational speed fluctuation of the compressor.