Three-Phase Rectifier Circuit for Air Conditioner IPM Voltage Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-phase power supply systems, the high-voltage direct-current bus voltage exceeds the input voltage requirements of Intelligent Power Modules (IPM) for direct-current fan loads and auxiliary power supplies, leading to unbalanced three-phase currents and significant harmonic issues due to the need for additional independent phase voltage rectification, which fails to meet International Electrotechnical Commission (IEC) harmonic requirements.
Innovation Solution
An electronic circuit comprising a three-phase rectifier module with a bidirectional switch assembly and an energy storage module, where two capacitors are connected in series, allowing direct-current loads with low voltage resistance to be powered directly from the capacitors, balancing three-phase currents and reducing harmonic distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct-current loads are powered by additional independent phase voltage rectification, then the input voltage requirement of IPM is met, but three-phase current balance deteriorates and harmonic increases
Solution Approach 1:
The patent merges the power supply for direct-current loads with the three-phase rectifier system by connecting loads to the midpoints of bridge arms. This integration allows the loads to share the rectified voltage from the same phases, ensuring current balance and reducing harmonic distortion while meeting voltage requirements.
Solution Approach 2:
The patent uses the midpoint of the bridge arm as an intermediary connection point between the rectifier circuit and direct-current loads. This intermediary provides a voltage that satisfies the IPM input requirements without requiring separate rectification, thereby maintaining three-phase current balance.
2Device complexity
If direct-current loads are connected to high-voltage direct-current bus, then power supply simplicity is improved, but voltage exceeds IPM input requirement
Solution Approach 1:
The patent applies local quality by providing different voltage levels to different parts of the system. The high-voltage direct-current bus supplies the variable-frequency compressor, while the midpoint of the bridge arm provides a lower voltage suitable for IPM-powered direct-current loads, optimizing both power supply efficiency and component compatibility.
3Reliability
If separate rectification is used for direct-current loads, then voltage requirement is satisfied, but load on one phase becomes higher than others
Solution Approach 1:
The patent combines the power supply paths by connecting direct-current loads to the rectifier bridge midpoints rather than using separate rectification. This merging distributes the load across multiple phases through the shared rectifier circuit, ensuring balanced phase currents and improved productivity.
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 provides stable voltage and balances three-phase currents, effectively reducing harmonic distortion, ensuring compliance with IEC standards by powering direct-current loads through the energy storage module, thus avoiding the need for additional independent phase voltage rectification.
Implementation Method 1
the energy storage module includes two capacitors connected in series to each other
Implementation Method 2
the rectifier module includes a three-phase rectifier bridge
Data Source
AI summary
An electronic circuit includes a rectifier module and an energy storage module. The rectifier module includes a three-phase rectifier bridge including first, second, and third bridge arms connected in parallel to each other, and a bidirectional switch assembly including first, second, and third bidirectional switches. One ends of the first, second, and third bidirectional switches are connected to midpoints of the first, second, and third bridge arms, respectively. The energy storage module is connected to a direct-current output end of the rectifier module and includes two capacitors connected in series to each other. One of the two capacitors is connected in parallel to a direct-current load. Other ends of the first, second, and third bidirectional switches are connected between the two capacitors.