Boost type resonant LCL-T converter for autonomous power supply system from renewable sources
Relevance. Autonomous electrical supply from renewable sources in oil-gas equipment is considered more and more due to ecology concerns. The requirements set by the power supply system to the converter include high efficiency and wide load range including idle. The latter is quite serious taking int...
| Main Authors: | , |
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| Format: | Article |
| Language: | Russian |
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Tomsk Polytechnic University
2018-04-01
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| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya-tpu.ru/archive/article/view/2003 |
| Summary: | Relevance. Autonomous electrical supply from renewable sources in oil-gas equipment is considered more and more due to ecology concerns. The requirements set by the power supply system to the converter include high efficiency and wide load range including idle. The latter is quite serious taking into account intrinsic property as a current source of photovoltaic. Direct conversion is impeded and required high loop gain as well as high speed in a control circuit. Current work examines resonant converter topologies for solar sources assuring soft commutation as well as parametric stabilization of the output voltage in full load range due to load impedance transformation. The aim of the research is the analysis of electrical properties of boost resonant LCL-T converter for photovoltaics along with efficiency of the one. Methods: basic electric circuit theory, algebraic equations, computational solving as well as modern instrumental systems and numerical simulation. Results. It is shown that current fed resonant LCL-T converter needs active rectifier to achieve parametric output voltage stabilization by recuperation energy out of output filter into resonant tank. That solution has high static losses because they are determined by the photovoltaic's current. Use of boost topology allowed divert source's current between bridge converters thus less static losses to achieve 98 % efficiency at nominal load. The authors have examined the properties of boost type resonant LCL-T converter controlled by PWM. Current and voltage values within the full control range do not exceed nominal ones due to mitigation of gain rise by declining source (solar battery) current. The gain increase is caused by the phase shift between current and voltage. LCL-T converter assures soft commutation of the transistors without frequency adjustment needed in typical series resonant converter. Validation of the result obtained is provided, conclusions are given. |
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| ISSN: | 2500-1019 2413-1830 |