Minhui Qian

Active and Reactive Power Control of Wind Farm Based on Integrated Platform of PowerFactory and MATLAB

The integration of large-capacity wind energies into a power system creates big challenges to the power system operation and control due to the intrinsic intermittence of wind energies, which constrains further developments of wind power generation. Countries around the world including Europe, USA and China have all made Grid Codes with clear requirements on active and reactive power controls in a wind farm. By effective active and reactive power controls, wind power curtailments can be substantially reduced. Furthermore, there have been no mature simulation and analysis platforms in China on testing correctness and rationality of wind farm control strategies so far. This chapter reports our research as well as engineering practices on building an integrated active and reactive power control system for wind farms using PowerFactory and MATLAB. The highlights that make this work unique are as follows: (i) the integration of PowerFactory and MATLAB makes the active and reactive power control modelling efficient and flexible; (ii) both the real measurements of wind speeds and the active power forecasted from history data are inputted in text file format to each wind generator in PowerFactory; (iii) the reactive power control capabilities of wind generators are fully utilized to reduce the scale of the reactive power compensations installed in a wind farm or from the grid.

Investigation on power control validation system of wind plant based on measured data

The accuracy of wind plant power control strategy is the key to ensure the adaptability of the wind plant. Effective testing and verification are essential means for the correctness of the control strategy. In this paper, the principle of active and reactive power control system for wind plant is studied firstly, the implementation architecture of power control system of wind plant is analyzed then, the modules of the power control system of the wind plant is implemented according to the modular design thirdly. Finally, a wind plant model with practical engineering background is established to validate the feasibility of the proposed wind plant power control system by injecting the measured data.

Wide-area damping controller design of large-scale PV power plants in interconnected power systems

High penetration of photovoltaic (PV) generation has become a reality in many power systems. The impacts of large-scale grid-connected PV on low frequency oscillation stability cannot be ignored. This paper presents a method for the wide-area damping controller design for the suppression of inter-area oscillation using auxiliary signals in PV controller. Firstly, the capability of low frequency oscillation suppression using PV is investigated. Then a low order damping controller for inter-area oscillation suppression is designed based on phase compensation. Dominant mode ratio (DMR) is also employed to select the optimal feedback signals of supplementary controller. Finally, a simulation model of two-area four-generator system with a large-scale grid-connected PV power plant is established. The effectiveness of damping controller is validated both from the results of eigenvalue analysis and time domain simulations.

Construction policies of distributed power generation

This paper is about the construction policies of distributed power generation. The distributed generation develops quickly in the whole world. The construction policies of each country can influence the industry development essentially. Construction policies of distributed generation can be considered from three aspects: the distributed power generation admission policy, the grid construction costs policy and the governments encourage policy. The governments adjust policies to influence the developing direction of distributed power generation. Good results are obtained in the practice.

Model validation of a wind farm using hybrid data simulation

Model accuracy of wind farms is the key factor to investigate the mutual influences between them and a power grid. However, this problem has not been well solved, especially in how to apply the real measurements to validate the models of wind farms. This paper presents a model validation methodology for wind farm via the hybrid data dynamic simulation. First, several typical hybrid data simulation methods are introduced and variable impedance method of them is especially described, merits of it is analyzed. Second, the implementation scheme of variable impedance method is investigated in DIgSILENT PowerFactory. At last, a real application via the variable impedance hybrid data simulation method in power system of north China is studied, which illustrates the effectiveness of the hybrid data simulation method in wind farm model validation.

Study on low frequency oscillation suppression of PV generation based on reactive power modulation

With fast development of large-scale photovoltaic (PV) power generation, the effect on low frequency oscillation caused by PV has been received widespread attention, and the use of low frequency oscillation suppression through PV has become a focus of current researches. In the paper, the feasibility of PV generation to suppress the low frequency oscillation is analyzed firstly, secondly, the effect of PV integration into a power system is analyzed, then an additional controller is designed to stabilize the low frequency oscillation with reference to the conventional PSS structure, and last, a chain system is established on DIgSILENT PowerFactory software, control effects both with and without the designed controller to stabilize the low frequency oscillations are simulated, and the results show that the designed controller could improve the small-signal stability of the power system.

Modeling Comparison on Control System of Synchronous Generator between DIgSILENT Power Factory and PSASP

 Abstract—PSASP is a widely used power system analysis program in China, and it provides various measured models and corresponding parameters of synchronous generators control system. DIGSILENT Power Factory is a popular power system analysis software package around the world. In this paper, some commonly used models in PSASP are established in DIGSILENT Power Factory. The contrast effect is implemented by conducting small perturbation and large disturbance in a two-area four-machine system at last.