scholarly journals Multi-Time Scale Rolling Economic Dispatch for Wind/Storage Power System Based on Forecast Error Feature Extraction

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2124 ◽  
Author(s):  
Li Han ◽  
Rongchang Zhang ◽  
Xuesong Wang ◽  
Yu Dong

This paper looks at the ability to cope with the uncertainty of wind power and reduce the impact of wind power forecast error (WPFE) on the operation and dispatch of power system. Therefore, several factors which are related to WPFE will be studied. By statistical analysis of the historical data, an indicator of real-time error based on these factors is obtained to estimate WPFE. Based on the real-time estimation of WPFE, a multi-time scale rolling dispatch model for wind/storage power system is established. In the real-time error compensation section of this model, the previous dispatch plan of thermal power unit is revised according to the estimation of WPFE. As the regulating capacity of thermal power unit within a short time period is limited, the estimation of WPFE is further compensated by using battery energy storage system. This can not only decrease the risk caused by the wind power uncertainty and lessen wind spillage, but also reduce the total cost. Thereby providing a new method to describe and model wind power uncertainty, and providing economic, safe and energy-saving dispatch plan for power system. The analysis in case study verifies the effectiveness of the proposed model.

2020 ◽  
Vol 309 ◽  
pp. 05015
Author(s):  
Song Gao ◽  
Linyu Wang ◽  
Lei Guo ◽  
Zhifeng Qiu ◽  
Yueshuang Bao

In this paper, the optimal charging and discharging schedules of electric vehicle (EV) are studied considering wind power under the condition of distribution network. In view of the uncertainty of EV charging-discharging demand and wind power output, the Markov decision process is adopted to model the randomness of supply and demand. Considering the dimensional disaster caused by dispatching a large number of EVs’ charging and discharging behavior in a centralized way, this paper proposes the two-layer dispatching model based on Markov decision process. First, the lower EV agents are responsible for collecting the real-time charging-discharging demands for EV and report to the upper dispatching center. Then the upper dispatching center gives the optimal charging and discharging power according to the real-time distribution operating status, wind power output and the EV information reported by each EV agent. Last, the lower agent gives the optimal charging-discharging sequence of each EV according to the upper optimal power. The goal of the upper dispatching center considers the power losses in the distribution network, load variance and the matching degree between EV charging-discharging and wind power output. The goal of the lower EV agent considers the EV charging-discharging fees and costs by EV battery losses. When deciding the optimal charging strategy, we design the two-layer Rollout algorithm to decide the optimal charging-discharging strategy considering the impact on future strategy decisions by current strategy decisions. Finally, the optimal results under four different strategies are simulated on the IEEE 30-bus distribution network system. The simulation results show that the proposed model and strategy can effectively reduce the distribution network losses and load variance, and greatly improve the utilization rate of wind power. Compared to the cost of uncoordinated EV charging, EV charging-discharging fees and battery loss costs by the proposed strategy have been greatly reduced.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2195 ◽  
Author(s):  
Tong Guo ◽  
Yajing Gao ◽  
Xiaojie Zhou ◽  
Yonggang Li ◽  
Jiaomin Liu

Due to the randomness, volatility and intermittent nature of wind power, power systems with significant wind penetration face serious “curtailment” problems. The flexibility of a power system is an important factor that affects the large-scale consumption of wind power. Based on this fact, this paper takes into account the economics and flexibility of the system, and proposes an optimal scheduling method that takes the flexibility of each thermal power unit into account. Firstly, a comprehensive evaluation index system of thermal power unit flexibility is designed by an analytic hierarchy process and entropy method. The system covers the technical indexes and economic characteristics of thermal power units and is able to quantitatively evaluate the different types of thermal power units in the system. Secondly, a multi-objective optimization scheduling model involving the overall flexibility of the unit and the total power generation cost is established. Finally, the correctness and effectiveness of the proposed indicators and models are verified by a case study.


2012 ◽  
Vol 580 ◽  
pp. 155-159
Author(s):  
Xiang Ming Wang ◽  
Jin Chao Wang ◽  
Dong Hua Sun

In this paper, the real-time EtherCAT technology is introduced in detail, which including operating principle, communication protocol and the superiority performance of EtherCAT i.e. synchronicity, simultaneousness and high speed. To show how to design a slave system that considering the characteristics of application, the method of developing systems based no EtherCAT technology are proposed. Finally, a data acquisition system based on EtherCAT technology is designed. Application of EtherCAT technology can improve the real-time characteristics of data communication in wind power system.


2014 ◽  
Vol 986-987 ◽  
pp. 404-411
Author(s):  
Qi Yang ◽  
Xin Zeng ◽  
Qing Kui Guo ◽  
Yong Yu Yuan ◽  
Jian Jun Sun ◽  
...  

Through the summary of typical accident, the problem between the over speed protection device of thermal power unit steam turbine and over frequency generator tripping measure is analyzed in island operation of sending ends of regional grid. The optimizing allocation principle between over frequency generator tripping measure and over speed protection equipment is put forward. By a variety of program analysis and comparison, the optimizing scheme is given. Finally, the typical models of thermal power unit steam turbine over speed protection are established in software. Based on a practical power system as an example, the whole process of islanding is simulated. Checking the coordination with existing over frequency generator tripping measure and the relay setting related to power network in the islanding operation, the validity and practicability of the optimal scheme and principle are analyzed. With the method, the regional grid will remain safe and stable.


2013 ◽  
Vol 380-384 ◽  
pp. 2972-2976
Author(s):  
Xiang Yu Lv ◽  
Tian Dong ◽  
Ye Yuan ◽  
De Xin Li ◽  
Xiao Juan Han

Large scale wind power integration has influenced the safety of power system. Taking wind power integration in Jilin as example, the paper describes the influencing factors of large scale wind power integration on reactive power of the grid in detail firstly, then analyze the reactive voltage in four typical ways, and discuss the impact of the wind power fluctuations on the grid reactive voltage.


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