Power transforming apparatus and air conditioner including the same
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Solution Overview
Problem
Existing power transforming apparatuses in air conditioners suffer from stress and reduced lifespan of power semiconductor devices due to unnecessary switching and uneven distribution of stress among converters, leading to increased heat generation and inefficiency in PFC operations.
Innovation Solution
A power transforming apparatus that dynamically adjusts the number of converter channels based on input power and motor speed, disperses switch stress by alternating converter channels, and applies hysteresis conditions for stable phase control, reducing unnecessary switching and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If individual phase control of converters is not carried out, then control complexity is reduced, but unnecessary switching occurs and maximum efficiency cannot be guaranteed
Solution Approach 1:
The patent implements dynamic phase control where the controller actively adjusts the switching phases of multiple converters based on real-time operating conditions. The controller determines optimal phase shifts to minimize unnecessary switching while maintaining efficiency, transforming the static control approach into a dynamic adaptive system that responds to load variations and converter states.
2Device complexity
If gate signal always operates one phase first, then control sequence is simplified, but stress is added to specific power semiconductor devices reducing their lifespan
Solution Approach 1:
The patent implements periodic rotation of the operating phase sequence among multiple converters. Instead of always operating one phase first, the controller cycles through different phase sequences, ensuring that each power semiconductor device gets periodic rest intervals. This rotational phase operation distributes cumulative stress evenly across all devices, extending their operational lifespan while maintaining simplified control logic.
3Device complexity
If stress is added to specific power semiconductor devices, then control is simplified, but performance imbalance occurs and heat generation of reactor increases
Solution Approach 1:
The patent segments the total power conversion load across multiple parallel converter phases, each handled by separate power semiconductor devices. The controller distributes switching operations and stress evenly among these segmented phases through coordinated phase control. This segmentation prevents any single device from bearing excessive stress, reducing localized heat generation in associated reactors and improving overall thermal management.
Data Source
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AI summary
The present disclosure discloses a power transforming apparatus capable of reducing a stress of a converter switch during a PFC operation, an operation method thereof, and an air conditioner including the same. To this end, the power transforming apparatus according to the present disclosure may determine the number of converters for performing a PFC operation based on a magnitude of input power and a speed of the motor. Furthermore, target converter channels are arbitrarily selected using a random function at an initial stage of a PFC operation so as not to add a stress to a switch device of any one converter. In addition, in order to disperse a stress to all switches, phases are individually controlled to perform switching operations while changing converters that match the number of converters for performing a PFC operation in a preset cycle, for example, whenever a zero-crossing is detected.