Compressor Inverter Preheating Control to Reduce Electromagnetic Noise
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Solution Overview
Problem
Air conditioners face challenges in reducing noise and power consumption during compressor preheating, particularly due to the ringing phenomenon of switching devices, which affects the accurate detection of output current.
Innovation Solution
A compressor driving apparatus that includes a capacitor connected to a DC terminal, an inverter with three-phase switching devices, and a controller that outputs a switching control signal comprising only non-zero vectors to reduce electromagnetic noise and power consumption by selectively turning on/off switching devices during preheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If switching devices are used to control the compressor motor during preheating, then the compressor can be preheated efficiently, but electromagnetic noise and ringing phenomena occur affecting current detection accuracy
Solution Approach 1:
The patent introduces an intermediary calculation method to resolve the conflict between using switching devices for efficient preheating and maintaining current detection accuracy. Instead of directly detecting current during switching operations, the system calculates output current indirectly using voltage measurements and impedance characteristics. This intermediary approach allows the switching devices to operate normally for efficient preheating while obtaining accurate current information through calculation rather than direct detection during the switching transitions.
2Power
If all three-phase switching devices are turned on/off during preheating, then maximum heating power is achieved, but electromagnetic noise increases significantly
Solution Approach 1:
The patent applies partial action by selectively controlling the switching devices rather than operating all three-phase switching devices simultaneously. The controller turns on only the necessary switching devices required to achieve the preheating function, leaving others in an off state. This partial operation reduces electromagnetic noise and ringing phenomena while still providing sufficient heating power to preheat the compressor motor effectively, avoiding the excessive electromagnetic interference that would result from all switching devices operating at full capacity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively preheats the compressor while minimizing electromagnetic noise and power consumption by using non-zero vectors, improving the efficiency and performance of the air conditioner.
Implementation Method 1
an inverter, including a plurality of three-phase switching devices, to convert DC power from the capacitor into AC power to drive the compressor motor
Implementation Method 2
the controller performs control such that some of the three-phase switching devices in the inverter are turned on or off in a compressor preheating mode, thereby reducing the amount of electromagnetic noise
Implementation Method 3
compressor preheating mode... preheat the compressor... reduce power consumption
Data Source
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AI summary
A compressor driving apparatus and an air conditioner including the same, whereby the compressor driving apparatus includes a capacitor connected to a DC terminal, an inverter, including a plurality of three-phase switching devices, to convert DC power from the capacitor into AC power to drive a compressor motor, an output current detector to detect output current flowing in the motor, and a controller to output a switching control signal for controlling the inverter based on the output current, wherein the controller performs control such that some of the three-phase switching devices in the inverter are turned on or off in a compressor preheating mode.