Universal electromechanical transient state model of grid-connected photovoltaic power generation system

Abstract

The invention relates to a universal electromechanical transient state model of a grid-connected photovoltaic power generation system. The universal electromechanical transient state model of the grid-connected photovoltaic power generation system is characterized by comprising a photovoltaic (PV) cell unit, a maximum power point tracking (MPPT) unit, a direct current (DC) transformation unit, a DC interlinking unit, an inverter unit with current inner ring control, an inverter outer ring control unit and a protective unit, wherein the input end of the PV cell unit inputs illumination intensity S and a PV cell temperature parameter T; the output end of the PV cell unit outputs power PV1 to the DC transformation unit and outputs maximum power point voltage VPVM to the MPPT unit; the DC transformation unit outputs terminal voltage VPV1 to the PV cell unit; the MPPT unit outputs power point voltage VPVM1; and the DC interlinking unit inputs direct current side power PPV3 from the DC transformation unit. The universal electromechanical transient state model of the grid-connected photovoltaic power generation system can provide a universal mathematic model applicable to electromechanical transient state analysis to the real grid-connected photovoltaic power generation systems with diversified structures, various forms and confidential inner parameters and contributes to analyzing, designing and controlling various grid-connected photovoltaic power generation systems in the whole microgrid system.

Description

technical field [0001] The invention relates to a general electromechanical transient model of grid-connected photovoltaic power generation system, which is a modeling method of photovoltaic power generation system in the field of photovoltaic PV and power system analysis. It belongs to the technical field of electric power transmission and distribution. Background technique [0002] With the development of new energy, smart grid and micro grid technology, grid-connected photovoltaic power generation system has been widely used and has broad development prospects. In the dynamic analysis of power grids containing photovoltaic power generation systems, transient models with both accuracy and efficiency need to be used. In previous studies, photovoltaic power generation system models usually use two types of models: one is the power flow model, which is modeled as a simple Power source, regardless of its dynamic process, this type of model is often called "power flow" model, ...

AI Technical Summary

Problems solved by technology

In the dynamic analysis of power grids containing photovoltaic power generation systems, transient models with both accuracy and efficiency need to be used. In previous studies, photovoltaic power generation system models usually use two types of models: one is the power flow model, which is modeled as a simple Power source, regardless of its dynamic process, this type of model is often called a "power flow" model, which is only suitable for power flow analysis, not for transient analysis

The other is to establish a corresponding circuit or electromagnetic model based on a specific photovoltaic power generation system, which strictly reflects the specific maximum power tracking (MPPT) control algorithm and inverter circuit and its control logic in the photovoltaic power generation system. Although this type of model can satisfy Power grid electromechanical transient analysis requirements, but there are the following problems: (1) Due to the internal structure (such as single-stage or double-stage) and control methods (such as various MPPT control strategies) of photovoltaic power generation systems vary from manufacturer to manufacturer different manufacturers and models of photovoltaic power generation systems, the workload is huge, the efficiency is low, and it is not practical; (2) the circuit or electromagnetic model of the built model involves the special Some internal parameters of equipment, some of these internal parameters are commercial secrets, and it is difficult to obtain relevant model parameters, which brings difficulties to modeling; (3) The circuit or electromagnetic model is complex, in order to ensure accuracy, the calculation step size is set very low, which seriously restricts The speed of analysis and calculation is low

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