Impact of disorderly charging of electric vehicles on the power grid

With the development of my country's energy strategy and the implementation of low-carbon actions, electric vehicles have been gradually widely used, and the application of electric vehicles is in line with the requirements of today's society for environmental awareness and effective savings in fossil fuel consumption. Due to its advantages of no pollution emissions and the attention of government departments, electric vehicles will become an important means of transportation in the future. Since a large number of electric vehicles are randomly connected to the power grid as loads for charging, it will inevitably cause a considerable impact on the power transmission and distribution network, seriously affecting its economic benefits and power quality, and sometimes even affecting its stable and smooth operation. This article mainly starts from the impact of disorderly charging of electric vehicles on the power grid, and analyzes the current research status of orderly charging scheduling countermeasures.

01

Impact of disorderly charging of electric vehicles on the power grid

Factors affecting electric vehicle charging. Electric vehicles are different from other loads in that they are random. Therefore, it is necessary to fully consider the factors that affect their changes and establish an ideal load probability model in order to more realistically simulate the disordered charging of electric vehicles and study their impact on the power grid. Therefore, the current research on the impact of electric vehicle charging on the power grid usually selects different random variables to model through the Monte Carlo simulation method, and obtains the electric vehicle charging power load probability model, which is then superimposed and compared with the original load curve to analyze its impact on the power grid. It is also possible to calculate the power flow of the distribution system and analyze the simulation results of electric vehicle charging on the power system voltage and network loss under different conditions by connecting the electric vehicle load obtained by modeling, to illustrate the impact of electric vehicle charging on the distribution network. The IEEE33 standard distribution system is usually selected as the research object, as shown in Figure 1.

Figure 1 IEEE 33-node distribution network system

02

Orderly charging research process

2.1 Objective function considered in the orderly charging research process

In the literature review of the current orderly research on electric vehicles, it is found that the charging goals are controlled mainly through several aspects, which are also considered from the perspective of individual users and the power grid.

(1) Minimize the peak-valley load difference of the power grid

(2) The load curve variance is small. The objective function is to minimize the square of the load number in the period minus the daily average load.

(3) User charging costs are relatively low

(4) The peak value of the charging curve is small

(5) The charging completion time of electric vehicles is shorter

(6) Maximizing the economic benefits of charging station operations

2.2 Constraints considered in the orderly charging research process

2.2.1 Electric vehicle charging capacity

The amount of electricity in an electric vehicle after charging should be greater than or equal to the starting amount of electricity.

2.2.2 User Charging Time

2.2.3 The cost of the charging process is relatively low

2.2.4 The regional basic load remains constant

2.2.5 Distribution network load upper limit

2.2.6 Line heat load constraints

2.2.7 Constraints on the number of charging piles in the region

Considering the limitation of the number of charging piles within the jurisdiction, if the charging capacity of electric vehicles within the unit is too large, the waiting period for charging will be too long, which will seriously affect the normal use of users. Therefore, the number of charging piles needs to be considered.

03

Ankerui Charging Pile Charging Operation Cloud Platform

3.1 Overview

AcrelCloud-9000 charging column charging operation cloud platform system uses the Internet of Things technology to continuously collect and monitor data from the electric bicycle charging stations and various charging systems connected to the system, monitor the operation status of the charging piles in real time, and provide charging services, payment management, transaction settlement, capital management, power management, detailed inquiries, etc. At the same time, it warns of various faults such as over-temperature protection, leakage, input/output overvoltage, undervoltage, and low insulation of the charger; the charging pile supports Ethernet, 4G or WIFI to access the Internet, and users can charge through WeChat, Alipay, and Cloud QuickPass.

3.2 Application areas

It is applicable to the design of charging infrastructure with charging pile modes for civil buildings, general industrial buildings, residential communities, industrial units, commercial complexes, schools, parks, etc.

3.3 System Structure

3.3.1 The system is divided into four layers:

Data collection layer, network transmission layer, data layer and client layer.

3.4 Functions of Ankerui Charging Pile Cloud Platform System

3.4.1 Intelligent large screen

The intelligent large screen displays the site distribution, displays the equipment status, etc., and can also view the site information of each site, the list of charging piles, etc. It can uniformly manage the charging piles in the community, view the equipment utilization rate, and allocate resources reasonably.

3.4.2 Real-time monitoring

Real-time monitoring of the operating status of charging facilities, mainly including the operating status of charging piles, circuit status, etc.

3.4.3 Transaction Management

Platform administrators can manage charging user accounts and perform operations such as recharge, refund, freeze, and cancel their accounts. They can also view detailed information on daily charging transactions of community users.

3.4.4 Fault Management

3.4.5 Statistical analysis

Through the system platform, you can query charging transaction statistics, energy consumption statistics, etc. from different angles such as charging stations, charging facilities, charging time, and charging methods.

3.4.6 Basic Data Management

By establishing operators on the system platform, operators can establish and manage the sites and charging facilities required for their operations, maintain charging facility information, price strategies, freezing and unbinding, etc.

3.4.7 Operation and Maintenance APP

It is designed for operation and maintenance personnel to manage sites and charging piles, perform closed-loop fault processing, query traffic card usage, query charging and recharging status, perform remote parameter settings, and receive fault push notifications.

3.4.8 Charging applet

It is designed for charging users to view nearby idle devices, mainly including functions such as scanning code to charge, account recharge, charging card binding, transaction query, fault complaint, etc.

3.5 System Hardware Configuration

04

Conclusion

Due to the government's support for the electric vehicle industry, the scale of electric vehicle production will continue to expand with the progress of the times. Such a large concentrated load connected to the power grid is bound to have a negative impact on the power grid. Therefore, in the future, it will be a normalized hot spot to study the orderly charging optimization strategy of electric vehicles. The reasonable and orderly control of electric vehicles as the *load will bring economic benefits to the power grid and users. Electric vehicles will bring less pollution to the ecological environment and meet the current pursuit of green energy development strategy; for power companies, reasonable electric vehicle charging scheduling of charging sequence, time, electricity price, etc. can make the power grid operation more economical and reliable. Future research in this area should also focus on the following issues:

(1) Pay more attention to user satisfaction with optimized charging scheduling and improve the economic incentive system so that electric vehicle users will voluntarily cooperate with scheduling.

(2) Simplify the charging system and match the user's charging behavior with the smartphone, allowing the user to monitor and manage the charging status through the phone;

(3) Focus on traffic conditions and the occupancy of charging piles. Combined with local electricity prices, personal needs of users and traffic conditions at the time, the optimal charging path and duration are provided to users, who can make their own decisions based on their actual personal conditions.