- Volume 12 Issue 6
DOI QR Code
Control of Linear Compressor System Using Virtual AC Capacitor
- Park, Shin-Hyun (Dept. of Electrical Engineering, Kyungpook National University) ;
- Choi, Jong-Woo (Dept. of Electrical Engineering, Kyungpook National University)
- Received : 2017.05.15
- Accepted : 2017.08.20
- Published : 2017.11.01
Recently, linear compressors of cooling systems such as refrigerators, which have a free piston driven by a linear motor, have attracted much attention because of their high efficiency. For structural reasons, linear compressors applied in refrigerators should use an AC capacitor to ensure stable control. However, AC capacitors are expensive and bulky. In this paper, we propose a new method to realize stable control without a real AC capacitor by implementing a virtual AC capacitor with software. To realize a virtual AC capacitor, a pure integral is calculated. Nonetheless, if an offset current exists, the calculation may diverge to infinity. To solve this problem, a high-pass filter is applied and the compensation for the phase angle and magnitude are realized with a new method. Finally, a virtual AC capacitor enables variable frequency operations. Hence, in case of a lack of voltage, we can compensate by running the linear compressor in high-frequency operations. To improve efficiency, we may optimize the operation frequency. The validity of a virtual AC capacitor has been verified through simulations and experimental results.
Supported by : Korea Institute of Energy Technology Evaluation and Planning (KETEP)
- Nan-Chyuan Tsai and Chao-Wen Chiang, "High-Frequency Linear Compressor and Lateral Position Regulation", IEEE Transactions on Control Systems Technology, vol. 20, no. 1, pp. 127-138, January 2012. https://doi.org/10.1109/TCST.2011.2105872
- Zhengyu Lin, Jiabin Wang, and David Howe, "A Learning Feed-Forward Current Controller for Linear Reciprocating Vapor Compressors", IEEE Transactions on Industrial Electronics, vol. 58, no. 8, pp. 3383-3390, August 2011. https://doi.org/10.1109/TIE.2010.2089948
- Jiabin Wang, David Howe, and Zhengyu Lin, "Design Optimization of Short-Stroke Single-Phase Tubular Permanent-Magnet Motor for Refrigeration Applications", IEEE Transactions on Industrial Electronics, vol. 57, no. 1, pp. 327-334, January 2010. https://doi.org/10.1109/TIE.2009.2025710
- Tae-Won Chun, Jung-Ryol Ahn, Jae-Yoo Yoo, and Chel-Woong Lee, "Analysis and Control for Linear Compressor System Driven by PWM Inverter", The 30th Annual Conference of the IEEE Industrial Electronics Society, pp. 263-265, 2-6, November, 2004.
- Tae-Won Chun, Jung-Ryol Ahn, and Hong-Hee Lee, "A Novel Strategy of Efficiency Control for a Linear Compressor System Driven by a PWM Inverter", IEEE Transactions on Industrial Electronics, vol. 55, no. 1, pp. 296-297, January 2008. https://doi.org/10.1109/TIE.2007.909730