Power Quality Evaluation And Operating Characteristics Analysis For Grid-connected Photovoltaic Power Station

As global energy crisis and environmental problems have become increasingly prominent, all countries in the world point the focus of changing the energy structure in future to the new energy industry. The solar energy has been payed more attention with many advantages, such as the wide distribution, clearing, no pollution, and the inexhaustible. Photovoltaic(PV) grid generation technology is rising quickly driven both by the progressive technology and the incentive national policy. However, when the photovoltaic power station accessed to the utility grid, because of the inherent characteristics and the change of grid structure and power flow, the adverse impact was made on many aspects, such as power quality, planning operation and relay protection. the The situation that the standard of grid-connected photovoltaic power is not perfect enough restricts the development of photovoltaic industry to some extent. This paper take the Huahan18MW grid-connected photovoltaic power station in Jining as the research object to make power quality testing and evaluation, the operating characteristics, the power quality influence and the effective improvement measure were researched when the photovoltaic power station accessed to the utility grid. These all gather experience for formulating effective and comprehensive testing and evaluation method of photovoltaic power station test and operation standardized and make for the further development and promotion of the grid-connected photovoltaic power station. the main content of this paper includes the following aspects.(1) The history, market dynamic and development trend of photovoltaic power in home and abroad is introduced and the structure and systematization is described. Based on the MATLAB/SIMULINK platform, the simulation model of photovoltaic cells is bulit, the Ⅰ-Ⅴ properties and the P-V properties are analyzed comparatively in the different illumination intensity and template working temperature conditions.(2) The power characteristics, power quality influence and power flow characteristics of grid-connected photovoltaic power station is described. The current situation of the grid-connected photovoltaic standard is introduced. On the basis of the technical rule for photovoltaic power station connected to power grid, one power quality testing and evaluation workprogramme of PV power station is formulated, the PV power station is evaluated and analysed from power quality, active power control, reactive power,voltage regulation and the dynamic response for mastering the current running conditions and power quality problems.(3) For the existing problems of harmonic and voltage fluctuation in the PV power station, the transmission performance of harmonic current is analysed equivalently based on the physical model of the transmission line, When the voltage sags occurred,the effect of voltage fluctuation improvement at the access point was studied by simulating the operation STATCOM at the MATLAB/SIMULINK platform. These can provide operating managers of PV power station with reference and suggestion to formulating reasonable and effective operating scheduling mode and improvement measures.