Issues of linearization of a twoaphase boost dcadc converter applied in the power supply systems operating on renewable energy sources
Renewable energy resources, for example, photovoltaic elements and wind turbines draw the increasing attention due to energy shortage and depletion of energy sources. Such energy sources usually give low voltage output. So the elementary photovoltaic electric power supply based on silicon gives abou...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | Russian |
| Published: |
Tomsk Polytechnic University
2017-09-01
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| Series: | Известия Томского политехнического университета: Инжиниринг георесурсов |
| Subjects: | |
| Online Access: | http://izvestiya.tpu.ru/archive/article/view/1840 |
| Summary: | Renewable energy resources, for example, photovoltaic elements and wind turbines draw the increasing attention due to energy shortage and depletion of energy sources. Such energy sources usually give low voltage output. So the elementary photovoltaic electric power supply based on silicon gives about 0,7 V EMF, and based on germanium - 0,4 V. However the possibilities of sequential accumulation of output potential are limited due to the need of increase in parallel branches of solar panels. The solution of this problem led to development of power supply systems on the basis of pulse-width boost converters. There is a task on improving the efficiency of this type of converters. In particular, to determine stability and research of dynamics in mathematical models of installations of power electronics the Jacobi's method is widely applied. While developing the power supply systems of different function the use of the Jacobi matrix increases their energy parameters. At the same time application of function of Poincare for iterative display of the Jacobi method makes it possible to determine the operating modes of the converter for specific points after changing the parameters of the system. Thus, Jacobi's matrix, being an dimensionless size, allows linearizing the characteristic in the fixed points for their analysis. Therefore, partial differentiation of nonlinear system gives the opportunity to obtain the fixed values, being the characteristic animator of the system - eigenvalues of a matrix. All the studies were carried out on the example of two-phase boost dc-dc converter with pulse frequency modulation. The peculiarity of the paper consists in use of the Jacobi matrix for linearizing non-linear systems when studying dynamics to determine steady and unstable modes of functioning of energy converters. Such mathematical approach allows increasing the efficiency and reliability of the voltage converter by identification of the abnormal dynamic operation modes in the device, reducing energy losses, i. e. increasing energy efficiency of a power supply system. The aim of the research is to develop an alternative method of linearization by using Jacobi's matrix to analyze stability of operation of various converters. The circuit of the studied converter assumes energy accumulation in inductive elements for shutdown at zero current or zero voltage. Results will be introduced in the form of display of Poincare through the Newton-Rafson-Jacobi method. Methods: review of technical publications, concerned the need of using Jacobi matrixes to analyze various converters stability. The control algorithm of two-phase pulse converter is simulated in LTSpice and MATLAB. The analysis of appropriate characteristics of TPBC includes Jacobi and Newton-Rafson methods. The latter has rather fast convergence and fine precision of discrete values. It is shown below in chaos and bifurcation modes. Results. The obtained eigenvalues define the operation modes of management system of TPBC, developed on the basis of the twophase pulse converter. These results will help to reveal those parameters of the system in case of which it functions in normal or abnormal statuses, thereby will allow separating one modes of functioning from others, and thus increasinge reliability and efficiency of the system. |
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| ISSN: | 2500-1019 2413-1830 |