Research on Urban Load Rapid Recovery Strategy Based on Improved Weighted Power Flow Entropy

Min Wang,Jian Zhou,Zongyin Fan,Shanshan Shi

doi:10.1109/access.2021.3051186

Min Wang, Jian Zhou + Show 2 more

Open Access

https://doi.org/10.1109/access.2021.3051186

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Abstract

As the final stage of power system restoration, the critical task of load restoration is to restore the remaining load as quickly as possible. With the continuous increase of the temperature-controlled load and the proportion of electric vehicle load in the urban power grid, the complexity of the load side in the restoration process gradually increases. Therefore, based on the existing grid environment, this paper considers the sudden increase in load recovery caused by cold load pick-up and the auxiliary effect of electric vehicle discharge on load recovery during the load recovery process. From the perspective of economy, safety, and speed, this paper establishes a multi-objective function that includes the amount of load, improved weighted power flow entropy, and the number of recovered lines. The multi-objective evolutionary algorithm based on decomposition is used to optimize the constructed multi-objective load recovery model. Through the IEEE30 node system, it is verified that the method proposed in this paper can effectively establish a fast and safe load recovery plan that meets the actual grid environment.

Highlights

The power system restoration is divided into three stages: black start, grid reconstruction, and load recovery [1]
As the penetration rate of temperature-controlled loads and electric vehicle loads in urban power grids is getting higher and higher, there are certain limitations in expressing the loads to be restored with a fixed power
Where f is the objective function to be optimized; f1, f2 and f3 respectively correspond to the weighted load recovery, the improved weighted power flow entropy, and the number of restored lines

Summary

INTRODUCTION

The power system restoration is divided into three stages: black start, grid reconstruction, and load recovery [1]. In view of the above problems, this paper proposes the following solutions, which are the innovations of this paper: 1) Combining the characteristics of urban temperature- controlled and the increasing load of electric vehicles, this paper considers the sudden increase in load recovery caused by the cold load pick-up and the auxiliary recovery effect of electric vehicle discharge in the recovery process; 2) This paper proposes to combine the network cohesion and the VOLUME 9, 2021 amount of load, from the two aspects of network topology and the amount of load, to effectively evaluate the weight of the load point in the process of load recovery and the restoration priority of loads of different load levels are considered in the restoration process; 3) This paper proposes improved weighted power flow entropy and use it as one of the objective functions, which can optimize the distribution of network power flow during the load recovery process and strengthen the robustness of the load recovery process. Where P(t) is the power function during the process of cold load pick-up; P0 is the load power at the normal time; Ppeak is the peak power of the load; t1 is the beginning time of attenuation; t2 is the moment when the load decrements to the normal load; α is cold load attenuation factor; u(t) is the unit step function

ELECTRIC VEHICLE CHARGING AND DISCHARGING POWER MODELING

CONSTRAINT CONDITIONS

SOLUTION OF MODEL

INITIALIZATION

Findings

VIII. CONCLUSION