AC-DC Converter Voltage Regulation for Air Conditioner DC Bus Stress
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Solution Overview
Problem
Existing AC-DC converters in air conditioning systems often regulate DC output voltage to a fixed level, leading to unnecessarily high voltage that can shorten the lifespan of sensitive components.
Innovation Solution
A converter system with a rectifier section, a voltage regulator section, and a controller that adjusts the DC output voltage to be greater than the AC input voltage by a variable offset, which can be fixed, percentage-based, or load-dependent, to manage voltage stress on components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the DC output voltage is regulated to a fixed high level to ensure sufficient voltage headroom for the inverter, then the inverter can operate reliably, but the voltage stress on sensitive electronic components increases, reducing their lifespan
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed DC output voltage regulation to a dynamic voltage regulation system. The controller continuously adjusts the DC output voltage based on real-time AC input voltage measurements, ensuring the minimum required voltage headroom for inverter operation while avoiding excessive voltage levels that would stress electronic components. This dynamic adjustment resolves the contradiction by making the voltage level adaptive rather than static.
Solution Approach 2:
The patent changes the voltage parameter from a fixed high level to a variable level that adapts to AC input conditions. By modifying the DC output voltage parameter dynamically based on AC input voltage measurements, the system maintains sufficient voltage headroom for reliable inverter operation while preventing excessive voltage stress on electronic components, thus resolving the lifespan contradiction.
2Stability of the object's composition
If the DC output voltage is set higher than necessary to account for voltage drops, then voltage stability is improved, but energy losses increase due to higher power dissipation
Solution Approach 1:
The patent implements feedback by continuously monitoring the AC input voltage and using this information to adjust the DC output voltage through the controller. This closed-loop feedback mechanism ensures voltage stability by maintaining adequate voltage headroom when needed while reducing voltage levels when AC input is high, thereby minimizing energy losses through reduced power dissipation in the process.
Solution Approach 2:
The system transitions from static voltage regulation to dynamic voltage regulation, where the DC output voltage continuously adapts to AC input voltage conditions. This dynamic behavior maintains voltage stability during varying operating conditions while avoiding sustained high voltage levels that would cause excessive energy losses, thus resolving the contradiction between stability and energy efficiency.
3Device complexity
If a fixed DC output voltage command is used in the control architecture, then the control system is simple to implement, but the DC output voltage cannot be optimized to reduce voltage stress on components
Solution Approach 1:
The patent introduces feedback by measuring the AC input voltage and using this measurement to dynamically adjust the DC output voltage command. This feedback mechanism adds minimal complexity to the control system while enabling optimization of the DC output voltage to reduce voltage stress on components, thus improving component reliability without significant increases in control system complexity.
Solution Approach 2:
The control system performs self-adjustment by automatically modifying the DC output voltage based on AC input voltage measurements. This self-service capability allows the system to optimize voltage levels for component protection without requiring complex external control mechanisms, resolving the contradiction between control simplicity and component reliability.
Data Source
AI summary
A converter for an air conditioning system including a rectifier section configured to receive an AC input voltage; a voltage regulator section coupled to the rectifier section, the voltage regulator section configured to control a DC output voltage across a positive DC bus and a negative DC bus; and a controller in communication with the rectifier section and the voltage regulator section, the controller configured to control the converter such that the DC output voltage is greater than AC input voltage by an offset.