Variable Speed Compressor Control Using Existing Thermostat Wiring
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Solution Overview
Problem
Existing temperature regulating systems that operate at constant speed require costly replacements of thermostats and wiring to upgrade to variable speed, which is inefficient and noisy.
Innovation Solution
A variable speed control method and controller that adjusts compressor speed based on system operation time and outdoor load without replacing the thermostat or wiring, using digital signals to regulate compressor speed dynamically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the single-speed motor is replaced by a variable-speed drive, then energy efficiency is improved and noise is reduced, but the cost increases due to replacement of thermostat and wiring
Solution Approach 1:
A communication unit is introduced as an intermediary component that enables the existing thermostat to send control signals to the variable-speed compressor through existing wiring. This intermediary allows the thermostat to control variable-speed operation without requiring replacement of the thermostat itself, thereby reducing upgrade costs while maintaining energy efficiency benefits
Solution Approach 2:
The existing thermostat is made multi-functional by enabling it to control both single-speed and variable-speed compressors through the communication unit. This allows the same thermostat hardware to adapt to different compressor types, eliminating the need for thermostat replacement and reducing overall system upgrade costs
2Object-affected harmful factors
If the single-speed motor is replaced by a variable-speed drive, then noise is reduced, but the cost increases due to replacement of thermostat and wiring
Solution Approach 1:
The communication unit serves as an intermediary that enables noise reduction through variable-speed operation without requiring expensive thermostat or wiring replacements. It translates existing thermostat signals into variable-speed control commands, achieving noise reduction at lower cost
3Adaptability or versatility
If the thermostat and wiring are replaced to enable variable speed operation, then system adaptability is improved, but device complexity increases
Solution Approach 1:
The communication unit acts as an adaptable intermediary that can interface with different thermostat types and control protocols while maintaining compatibility with existing wiring. This adds adaptability without requiring changes to the existing thermostat or wiring infrastructure, thereby avoiding increased system complexity
Data Source
AI summary
A variable speed control method, a variable speed controller and a method for operating the same are provided. The variable speed controller is preset with a first preset period of time. The method includes: receiving an on signal from a thermostat; driving a compressor at an initial system operation speed; monitoring a system operation time and monitoring an outdoor load; increasing the system operation speed if the system operation speed is less than a maximum system operation speed and the system operation time is greater than the first preset period of time; detecting a change in the outdoor load in an operation and regulating the system operation speed based on at least the change in the outdoor load; and determining whether an off signal from the thermostat is received, and turning off the compressor if the off signal is received. Therefore, the compressor can operate at variable speed.