Air Conditioner Motor Controller With Dynamic Frequency Selection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Air conditioners face issues with power loss and circuit element damage due to inefficient motor control, as existing systems do not adequately consider real-time variations in load and environmental factors like temperature and current, leading to unstable operations and potential overheating.
Innovation Solution
A motor controller for air conditioners that includes a converter, inverter, current detector, temperature detector, and controller to calculate loading based on room temperature, setup temperature, and inner unit capacity, setting a final target frequency to optimize motor operation and reduce power loss by considering detected current and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the motor controller operates at high frequency to meet high loading demands, then the cooling capacity and responsiveness are improved, but power loss increases and circuit elements may overheat
Solution Approach 1:
The patent implements dynamic frequency adjustment by continuously monitoring real-time current and temperature conditions, then adapting the motor operating frequency accordingly. The controller dynamically selects from multiple frequency tables (first through fourth frequency tables) based on detected conditions, allowing the system to optimize between cooling capacity and power loss in real-time rather than operating at fixed high frequency.
Solution Approach 2:
The patent changes operational parameters (frequency, current thresholds, temperature thresholds) based on detected conditions. Multiple frequency tables with different frequency values are prepared in advance, and the controller selects appropriate parameters from these tables according to real-time current and temperature measurements, thereby adjusting system operation to balance performance and energy efficiency.
2Productivity
If the motor controller increases operating frequency to handle high load, then the cooling effectiveness is improved, but circuit elements may be damaged due to overheating
Solution Approach 1:
The patent implements feedback control by continuously detecting current and temperature conditions, comparing them against predetermined thresholds, and adjusting the operating frequency accordingly. The controller receives feedback from detection circuits and modifies its output frequency based on this feedback, ensuring that circuit elements operate within safe temperature limits while maintaining effective cooling when conditions permit.
Solution Approach 2:
The patent prepares multiple frequency tables with progressively lower frequency values in advance of potential overheating conditions. When temperature or current thresholds are approached, the controller proactively switches to lower frequency tables before damage can occur, providing a cushioning effect that prevents circuit element failure while maintaining smooth transition from high to low frequency operation.
3Device complexity
If the motor controller uses fixed frequency operation, then the control system is simple, but it cannot adapt to real-time variations in load and environmental conditions
Solution Approach 1:
The patent transforms the static fixed-frequency control system into a dynamic adaptive system by introducing real-time detection of current and temperature conditions. The controller dynamically selects from multiple pre-prepared frequency tables based on detected conditions, providing adaptability to varying load and environmental conditions while maintaining relatively simple control logic through predetermined frequency tables rather than complex real-time calculations.
4Device complexity
If the motor controller operates without considering real-time temperature and current, then the control logic is simple, but power loss increases and circuit elements may overheat
Solution Approach 1:
The patent introduces feedback mechanisms that detect real-time current and temperature conditions without significantly complicating the control logic. The controller compares detected values against predetermined thresholds and adjusts frequency based on these comparisons, providing a relatively simple threshold-based feedback system that effectively reduces power loss by avoiding unnecessary high-frequency operation under unfavorable conditions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a motor controller for an air conditioner and a motor control method. The motor controller including a converter converting AC utility power into DC power and an inverter having a plurality of switching elements, the inverter receiving the DC power, converting the received DC power into AC power by switching operations of the switching elements, and supplies the AC power to a motor, the motor controller further including: a current detector detecting a current flowing in the motor controller; a temperature detector detecting a temperature in the motor controller or a temperature ambient to the motor controller; and a controller calculating a loading based on at least one of room temperature, setup temperature, and inner unit capacity and setting up a final target frequency for driving the motor based on the calculated loading and at least one of the detected current and the detected temperature. The motor controller for the air conditioner and the motor control method determines a target frequency considering a current and a temperature, to reduce power consumption and protect circuit elements.