scholarly journals Research on Variable Inertia Coordination Frequency Regulation Strategy Based on a Wind & Thermal Power Combined System

2019 ◽  
Vol 118 ◽  
pp. 02042
Author(s):  
Siqing Sheng ◽  
Pengwang Li ◽  
Hao Wu ◽  
Liwei Zhang ◽  
Maosen Fan

With the increasing installed capacity of the wind power, the power system has an obviously low inertia characteristic. It is of great significance to actively promote the virtual inertia frequency regulation technology of wind turbines (WTS) for improving the system frequency quality. The frequency regulation capability and frequency regulation effects of wind & thermal power units were analysed, and a variable inertia coordination frequency regulation strategy for different wind power penetration conditions was proposed in this paper. At the wind farm level, the dynamic frequency regulation participation coefficient of wind farms was fuzzily determined according to the operation conditions of WTS and the wind power penetration ratio. At the wind turbine level, the calculation method of the equivalent inertia constant of WTS was given based on the effective rotational kinetic energy. And the allowable range of frequency regulation parameters of WTS was determined by considering the incremental model of the system. Results indicated that the proposed coordinated frequency regulation strategy not only provided a reliable inertia support, but also maintained the stability of WTS. The frequency response performance of the high-penetration wind power system was improved.

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Mohamed Nadour ◽  
Ahmed Essadki ◽  
Tamou Nasser

The expansion of renewable generation has raised some red flags in terms of power system stability, control, and management. For instance, unlike traditional synchronous energy sources, the doubly-fed induction generator- (DFIG-) based wind turbines (WTs) do not instinctively act against frequency deviations. In fact, the power electronics interfacing the generator, merely controlled to warrant maximum wind power conversion, make its output power and mechanical speed immune to the characteristics of the electric network frequency. Moreover, significant wind power penetration (WPP) promotes the retirement of many traditional generation groups, consequently curtailing the power system corresponding inertia and displacing the primary reserves that are essential to retain the frequency within an acceptable range of variation. This paper explores different control approaches, using backstepping, allowing DFIG-based WTs to engage actively in frequency regulation using a coordinated control of the rotor speed and pitch angle to regulate the system during both partial- and full-load operation modes. The first method momentarily discharges part of the kinetic energy stored in the WT spinning masses, and the second method follows a deloaded operation characteristic, so as to keep a specific power reserve that can be automatically activated at the events of frequency excursions. A study case considering an isolated power system that consists of synchronous generators, DFIG-based wind farm, static load, and a sudden frequency disturbance was performed. The simulation result in a Matlab/Simulink environment highlights the robustness and capability of the coordinated control scheme to furnish, under variant operation conditions, active power aid, consequently lifting the frequency nadir up to a superior level than that obtained with 0% wind power penetration in the system.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2250
Author(s):  
Hubert Bialas ◽  
Ryszard Pawelek ◽  
Irena Wasiak

The article presents an original simulation model of a wind farm (WF) consisting of 30 wind turbine-generator units connected to the electrical power system (EPS) through power converters. The model is dedicated to the evaluation of the WF capabilities to participate in frequency and voltage regulation services in the power system. A system that allows for frequency and voltage control is proposed and implemented in the presented model. The system includes primary frequency regulation with synthetic inertia and secondary regulation available on request from the system operator. The concept of a reference power generation unit was introduced, according to which only one wind generator unit was modeled in detail, and the other units were replaced with simple current sources. Such a solution allowed for the reduction of size and complexity of the model as well as shortened the simulation time. Simulation tests were conducted in the PSCAD/EMTDC environment for an electrical power system composed of the wind farm, a synchronous generator, and a dummy load. The performance of the wind farm control system was analyzed in different operation conditions, and the control capabilities of the farm were assessed. Selected simulation results are presented and discussed in the paper. They illustrate the regulatory properties of the WF and confirm the correctness of the developed model.


Author(s):  
Junrong Xia ◽  
Pan Zhao ◽  
Yiping Dai

Due to the intermittence and fluctuation of wind resource, the integration of large wind farms in a power grid introduces an additional stochastic component to power system scheduling. This always brings challenges to maintain the stability of power system. Integrating gas turbine units with wind farms can compensate their output fluctuation. In this paper, a methodology for the operation scheduling of a hybrid power system that consists of a large wind farm and gas turbine units is presented. A statistical model based on numerical weather prediction is used to forecast power output of the wind farm for the next 24 hours at quarter-hour intervals. Forecasts of wind power are used for optimizing the operation scheduling. In order to study the dynamic performance of the proposed hybrid power system, dynamic modeling of this hybrid power system is addressed. Wind farm and gas turbine units are integrated through an AC bus, and then connected to a power grid. An aggregated model of the wind farm and detailed models of gas turbine units are developed, and are implemented using MATLAB/Simulink. Simulation studies are carried out to evaluate the system performance using real weather data. The simulation results show that the proposed hybrid power system can compensate fluctuating wind power effectively and make wind power more reliable.


2013 ◽  
Vol 448-453 ◽  
pp. 2556-2563
Author(s):  
Ye Kui Chang ◽  
Rao Liu ◽  
Chong Wang ◽  
Xin Zhang ◽  
Wei Dong Li

The third frequency adjustment is the key link of the grid frequency regulation. The admission of high capacity and rejection of small capacity policy on thermal power cause the lack of capacity of the third frequency adjustment. Wind power brings about a certain impact to the frequency stability of the power system, particularly, increasing the difficulty of the third frequency adjustment. The introduction of nuclear power into the third frequency adjustment has been proposed after analyzing the characteristics of the energy generation of different forms. This paper formulate the control strategy with the core of wind power decomposition, generator units grouping in the third frequency adjustment, after elaborating the technical feasibility and economic feasibility, and, come to a conclusion that the participation of the nuclear in the third frequency adjustment would guarantee the stability of the frequency of the power system with this control strategy in the case of the introduction of wind power to the system, by simulation analysis.


2012 ◽  
Vol 608-609 ◽  
pp. 742-747
Author(s):  
Chun Hong Zhao ◽  
Lian Guang Liu ◽  
Zi Fa Liu ◽  
Ying Chen

The integration of wind farms has a significant impact on the power system reliability. An appropriate model used to assess wind power system reliability is needed. Establishing multi-objective models (wind speed model, wind turbine generator output model and wind farm equivalent model) and based on the non-sequential Monte Carlo simulation method to calculate risk indicators is a viable method for quantitatively assessing the reliability of power system including wind farms. The IEEE-RTS 79 test system and a 300MW wind farm are taken as example.The calculation resluts show that using the multi-objective models can improve accuracy and reduce error; the higher average wind speed obtains the better system reliabitity accordingly.


2015 ◽  
Vol 737 ◽  
pp. 199-203
Author(s):  
Shao Hong Tsai ◽  
Yuan Kang Wu ◽  
Ching Yin Lee ◽  
Wen Ta Tsai

Modern wind turbine technology has been a great improvement over the past couple decades, leading to large scale wind power penetration. The increasing penetration of wind power resulted in emphasizing the importance of reliable and secure operation of power systems, especially in a weak power system. In this paper, the main wind turbine control schemes, the wind penetration levels and wind farm dynamic behavior for grid code compliance were investigated in the Penghu wind power system, a weak isolated power system.


2014 ◽  
Vol 644-650 ◽  
pp. 3840-3843
Author(s):  
San Ming Liu ◽  
Zhi Jie Wang ◽  
Xia Sun ◽  
Yi Teng Liang ◽  
Xiao Wei Zhu

The impacts of wind disturbance on voltage regulation and frequency regulation of power system were studied. The opinion that the regulation of power flow on the tie lines between the grids constrains the integrated capacity of wind power was put forward. Based on the real condition of Inner Mongolia power grid, an engineering practical method was put forward to calculate the integrated capacity of wind power under this constraint. The relationship between wind power and spinning reserve and the impacts of other related factors on the capacity of wind power were studied as well. The impact of wind disturbance on voltage stability where the wind farms are located was studied.


2014 ◽  
Vol 953-954 ◽  
pp. 557-560
Author(s):  
Qian Wang ◽  
Xue Shen ◽  
Ran Li

Integrated wind farms exert a growing influence in the economic operation of power system. Wind power is a form of intermittent and random energy. This paper introduces a model including the error in wind power forecasts using a probability or relative frequency histogram. Compared with the deterministic OPF, the proposed model allows the coordination of wind andthermal power while accounting for the expected penalty cost for not using all available wind power and the expected cost of calling up power reserves because of wind power shortage.Simulation results are presented for cases where the forecasting error histogram is eitherderived from historical data or estimated by a bimodal normal distribution.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Han Wang ◽  
Shuang Han ◽  
Yongqian Liu ◽  
Aimei Lin

The wind speed sequences at different spatial positions have a certain spatiotemporal coupling relationship. It is of great significance to analyze the clustering effect of the wind farm(s) and reduce the adverse impact of large-scale wind power integration if we can grasp this relationship at multiple scales. At present, the physical method cannot optimize the time-shifting characteristics in real time, and the research scope is concentrated on the wind farm. The statistical method cannot quantitatively describe the temporal relationship and the speed variation among wind speed sequences at different spatial positions. To solve the above problems, a quantification method of wind speed time-shifting characteristics based on wind process is proposed in this paper. Two evaluation indexes, the delay time and the decay speed, are presented to quantify the time-shifting characteristics. The effectiveness of the proposed method is verified from the perspective of the correlation between wind speed sequences. The time-shifting characteristics of wind speed sequences under the wind farms scale and the wind turbines scale are studied, respectively. The results show that the proposed evaluation method can effectively achieve the quantitative analysis of time-shifting and could improve the results continuously according to the actual wind conditions. Besides, it is suitable for any spatial scale. The calculation results can be directly applied to the wind power system to help obtain the more accurate output of the wind farm.


Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3566 ◽  
Author(s):  
Quanhui Che ◽  
Suhua Lou ◽  
Yaowu Wu ◽  
Xiangcheng Zhang ◽  
Xuebin Wang

With the grid-connected operation of large-scale wind farms, the contradiction between supply and demand of power systems is becoming more and more prominent. The introduction of multiple types of flexible resources provides a new technical means for improving the supply–demand matching relationship of system flexibility and promoting wind power consumption. In this paper, multi-type flexible resources made up of deep peak regulation of thermal units, demand response, and energy storage were utilized to alleviate the peak regulation pressure caused by large-scale wind power integration. Based on current thermal plant deep peak regulation technology, a three-phase peak regulation cost model of thermal power generation considering the low load fatigue life loss and oil injection cost of the unit was proposed. Additionally, from the perspective of supply–demand balance of power system flexibility, the flexibility margin index of a power system containing source-load-storage flexible resources was put forward to assess the contribution from each flexibility provider to system flexibility. Moreover, an optimal dispatching model of a multi-energy power system with large-scale wind power and multi-flexible resources was constructed, aimed at the lowest total dispatching cost of the whole scheduling period. Finally, the model proposed in this paper was validated by a modified RTS96 system, and the effects of different flexibility resources and wind power capacity on the optimal scheduling results were discussed.


Sign in / Sign up

Export Citation Format

Share Document