Equivalent circuit of photovoltaic generator using Newton‐Raphson algorithm

• Autores: Andreas D. Theocharis, Vasilis P. Charalampakos, Anastasios Drosopoulos, John Milias Argitis
• Localización: Compel: International journal for computation and mathematics in electrical and electronic engineering, ISSN 0332-1649, Vol. 31, Nº 4 (Special Issue: Selected papers from EHE 2011), 2012, págs. 1224-1245
• Idioma: inglés
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• Resumen

  • Purpose – The purpose of this paper is to develop a linearized equivalent electrical circuit of a photovoltaic generator. This circuit is appropriate to confront problems such as numerical instability, increased computational time and nonlinear/non‐canonical form of system equations that arise when a photovoltaic system is modelled, either with differential equations or with equivalent resistive circuits that are generated by electromagnetic transient software packages for power systems studies.

    Design/methodology/approach – The proposed technique is based on nonlinear and well‐tested ipv−vpv equations which are however used in an alternative mathematical manner. The application of the Newton‐Raphson algorithm on the ipv−vpv equations leads to uncoupling of the ipv and vpv quantities in each time step of a digital simulation. This uncoupling is represented by a linearized equivalent electrical circuit.

    Findings – The application of nodal analysis equivalent resistive circuits using the proposed equivalent photovoltaic generator circuit leads to a system model based on linear algebraic equations. This is in opposition to the nonlinear models that normally result when a nonlinear ipv−vpv equation is used. In addition, using the proposed scheme, the regular systematic methods of circuit analysis are fully capable of deriving the differential equations of a photovoltaic system in standard form, thus avoiding the time‐consuming solution process of nonlinear models.

    Originality/value – In this paper, a new method of using the ipv−vpv characteristic equations is proposed which remarkably simplifies photovoltaic systems modeling. Moreover, a very important practical application is that by using this methodology one can develop a photovoltaic generator element in electromagnetic transient programs for power systems analysis, of great value to power engineers who are involved in photovoltaic systems modeling.