Buck-converter-based drive circuits for driving motors of compressors and condenser fans
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage condenser fan motors in compressor systems are costly due to high peak voltage requirements, and existing solutions like transformers increase costs and size, while reducing peak voltage ratings.
Innovation Solution
The use of buck converters to downconvert high AC voltages to lower AC or DC voltages for condenser fan motors, reducing peak voltage requirements and enabling the use of lower-rated motors, with the option to pulse DC voltage for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If high-voltage condenser fan motors are used to match the high peak voltage from rectified power lines, then the motor can operate directly from the power lines, but the motor cost and size increase significantly
Solution Approach 1:
The patent changes the voltage parameter by introducing a buck converter that reduces the high peak voltage from rectified power lines to a lower voltage level suitable for standard-rated motors. This allows the use of lower-cost, smaller motors while maintaining operational compatibility with the power source through active voltage management.
2Ease of manufacture
If transformers are used to reduce peak voltage ratings for condenser fan motors, then the motor voltage rating can be reduced, but the system cost and size increase
Solution Approach 1:
The patent replaces the mechanical transformer with an electronic buck converter circuit. This substitution eliminates the need for heavy magnetic components and insulation infrastructure, reducing overall system size and cost while achieving the same voltage reduction objective. The electronic approach offers additional benefits of controllability and efficiency.
3Reliability
If high-voltage rated motors are used, then the motor can handle high peak voltages, but the motor becomes more specialized and costly
Solution Approach 1:
The patent introduces a buck converter as an intermediary device between the high-voltage power source and the motor. This intermediary actively manages the voltage transition, protecting the motor from high peak voltages while allowing the system to utilize the available power source. The motor operates in its optimal voltage range while the intermediary handles the voltage conversion.
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
This approach reduces the cost and size of condenser fan motors by lowering peak voltage requirements, allowing for more efficient and cost-effective operation while maintaining performance.
Implementation Method 1
a rectification circuit configured to rectify a first AC voltage signal to generate a rectified voltage signal
Implementation Method 2
a buck converter configured to downconvert the rectified voltage signal to a DC voltage signal
Data Source
AI summary
A drive circuit is provided and includes a rectification circuit, a buck converter, a first inverter, and a second inverter. The rectification circuit is configured to rectify a first AC voltage signal to generate a rectified voltage signal. The buck converter is configured to downconvert the rectified voltage signal to a DC voltage signal, wherein the DC voltage signal is supplied to a DC bus. The first inverter is configured to convert the DC voltage signal to a second AC voltage signal and supply the second AC voltage signal to a compressor motor. The second inverter is configured to convert the DC voltage signal to a third AC voltage signal and supply the third AC voltage signal to a condenser fan motor. Peak voltages of the second AC voltage signal and the third AC voltage signal are less than peak voltages of the first AC voltage signal.