Study on grid adaptability testing methodology for wind turbines

Abstract

The use of wind power has grown rapidly in recent years. Wind power is a clean source of energy, but can have negative impacts on the distribution grid. The influence of large-scale wind power integration on the safe and stable operation of a power system cannot be ignored. It is necessary and urgent to achieve grid adaptability for wind turbines in China. Using a 35 kV/6 MVA grid simulator, the performance of a grid is investigated by simulation. Typical grid disturbances such as voltage deviation, frequency fluctuation, voltage unbalance, and distortion can be simulated. A grid adaptability testing methodology was developed and applied to a doubly fed wind turbine with a focus on analyzing real test data to ascertain its three-phase voltage unbalance adaptability, which was successfully demonstrated. The methodology can also be used to guide other grid adaptability tests.

Harmonic Adaptability Remote Testing Method for Offshore Wind Turbines

“…The schematic diagram of grid simulator is introduced in [4]. The grid and grid simulator are connected together by the wind farm bus referred to in this paper as the onshore PCC.…”

“…Taking the 8th harmonic voltage testing for onshore WTs for example, the required distortion of the 8th harmonic voltage is 2.5% [4,5]. Figure 2a,b depict the standard testing voltage waveform and the frequency spectrum for 8th harmonic voltage, respectively.…”

“…Consequently, the winding parameter Z T connecting the excitation parameter Y T in parallel is used as the model of the transformer [19]. According to the topology of the grid simulator, it can be represented by a harmonic voltage source connecting an impedance in series [4,8].…”

“…With the increasing penetration of wind power in the grid, the adverse effects on grid security and stability cannot be ignored [2,3]. Therefore large-scale wind turbines (WTs) are necessary to remain connected and support the power system like the conventional power plants during grid disturbances such as frequency fluctuation, voltage deviation, voltage unbalance, and distortion, which is called the grid adaptability in whole [4,5]. On one hand, grid-connected WTs are one of the causes of power quality problems, and the measurement and assessment of their power quality characteristics must be performed by the certifier and/or manufacturer in laboratory to make sure that they are qualified [6].…”

Research on Multifunctional High-Power Grid Source Simulator System with Synchronous Generator, Line Impedance Imitation, and ZIP Load Emulator

“…With the increasing penetration of distributed generation (DG) [1][2][3][4] and large-scale renewable energy systems, more stringent grid codes [5][6][7][8][9][10][11][12] have been issued to prescribe how those grid-connected systems support the network during grid disturbances. These papers introduce the concept and approach of the European Network Code on Requirements for Generators (NC RfG; EU Commission regulation 2016/631).…”