Analysis on Several Issues in Developing Electric Vehicle Charging Infrastructure in my country

0 Introduction

In early 2010, the International Climate Organization interviewed 40 experts in the electric vehicle industry. The results showed that the importance of charging infrastructure construction ranked second among the many factors affecting the development of electric vehicles, surpassing the purchase price factor and second only to the battery technology improvement factor, which ranked first. All parties have reached a consensus on the basic and key role of charging facilities.

From the perspective of foreign development, although the construction of charging facilities in major developed countries is still in its infancy, the government support is very strong. From the perspective of domestic development, the main participants in the construction of charging facilities in China include State Grid Corporation, China Southern Power Grid Corporation, Putian Offshore Oil, Sinopec, BYD and other companies. In recent years, China has put into operation a certain number of charging stations and charging piles, with various charging methods such as fast charging, slow charging, and battery replacement. The preliminary work has provided valuable experience for subsequent construction. At present, State Grid Corporation, China Southern Power Grid Corporation, Putian Offshore Oil, Sinopec and other companies have signed strategic cooperation agreements with most local governments and formulated relatively clear construction goals and plans. The construction of charging stations has begun to show an accelerated development momentum.

Although the construction of charging infrastructure has been highly valued at home and abroad, all countries in the world are currently facing a series of problems such as unclear technical standards and operation models. China urgently needs to increase research and innovation efforts on the basis of pilot projects and explore a development path for charging infrastructure that is suitable for China's national conditions.

The service object of charging infrastructure is electric vehicles as a means of transportation, and its service content belongs to electricity services. Therefore, charging infrastructure has dual infrastructure characteristics. It is not only an important power service infrastructure, but also an important modern transportation infrastructure. It is of great significance to clarify the nature, attributes and relationship of charging infrastructure with the power grid.

1 The essence of charging service is to meet a new type of electricity demand

For electric vehicles, a new type of electricity user, its own characteristics determine that its electricity demand is quite different from that of ordinary electricity users, and it has three new characteristics: mobility, diversity and guideability.

1.1 The electricity demand of electric vehicles is mobile

Unlike the electricity demand of ordinary electricity users, the electricity demand of electric vehicles has significant mobility characteristics. This is because as a means of transportation, the same electric vehicle may be parked at multiple different locations, and its electricity demand will also move between different parking locations. Therefore, the "fixed-point electricity use, fixed-point billing" electricity service designed for traditional users is no longer applicable, and it is necessary to provide electric vehicle users with "multi-point electricity use, multi-point billing" electricity service.

1.2 Electric vehicle electricity demand is diverse

First, different types of electric vehicle users have different electricity demands. For example, there are large differences in electricity demands for electric buses, sanitation vehicles, taxis and private cars. Secondly, the same electric vehicle user has multiple electricity demands, including the demand for rapid battery replacement, as well as the demand for DC charging and AC charging.

1.3 Electric vehicle electricity demand is guideable

The electricity demand of electric vehicles is very guideable. Under the condition of effective guidance by means such as time-of-use electricity prices, it can play a role in peak-shaving and valley-filling, and improve the overall operation efficiency of the system. As for the slow charging technology currently used, the charging process can generally be completed in 5 to 8 hours. According to statistics, 90% of cars are parked 95% of the time, which means that through reasonable incentives and advanced smart grid technology, electric vehicle users can be guided to arrange charging time during the low-load period of the power grid to achieve friendly interaction with the power grid.

2 Networking is the basic attribute of charging infrastructure

From the current pilot stage, many pilot projects are mainly to build charging piles and charging stations for specific electric vehicle users. With the large-scale development of electric vehicles in the future, it is necessary to optimize the network layout of charging stations and charging piles from the perspective of system optimization and integration based on the three major characteristics of mobility, diversity and guideability of their electricity demand, and build an organic charging service network through a unified information management platform to achieve efficient, intelligent and standardized network construction and operation. Network attributes should become the basic attributes of charging infrastructure and serve as an important principle for the top-level design and planning layout of charging infrastructure in China.

2.1 Network construction and operation can adapt to the requirements of mobility and diversity of electric vehicle electricity consumption

For electric vehicle users, due to the mobility and diversity of their electricity demand, users will hope that infrastructure operators will provide multi-point charging services of "multi-point electricity use, multi-point billing" and diversified charging services combining multiple methods such as battery replacement, slow charging and fast charging. Such user needs determine that the construction and operation mode of charging facilities in China cannot be "decentralized operation and independent management", but must be in accordance with unified and standardized standards, according to the actual needs of users, reasonably configure service outlets and service methods, and provide users with networked and standardized charging services.

2.2 Network construction and operation are conducive to promoting the standardized and orderly development of the charging service industry.

Electric vehicle charging services are public services. Similar to the demand for mobile communication services, electric vehicle users need to enjoy standardized and continuous charging services in a large area, and do not want to see disorderly development and inconsistent standards. Building a strong charging network construction operator will help ensure that all charging facilities within the network coverage adopt unified standards, and ensure the standardization and consistency of a series of related public services such as charging metering and maintenance. At the same time, similar to mobile communication network services, relevant government management departments can also effectively regulate the development of the industry by issuing operating licenses for charging network services, avoiding problems such as inconsistent standards and inadequate services.

2.3 Network construction and operation are conducive to giving play to economies of scale and reducing system operation and maintenance costs

. In order to ensure the quality of charging and swapping services, operators must ensure that charging and swapping facilities have a certain degree of redundancy and backup. For example, the battery reserve rate of the swapping stations on the Beijing Olympic bus routes is 60%. If decentralized operation is adopted, a large number of backup facilities will be required to ensure service quality; however, through networked operation and management, intensive complementarity can be achieved, which will help reduce the total demand for backup facilities, give full play to the complementary benefits and scale benefits of networked operation of charging facilities, and save construction and operation costs. In addition, through advanced information communication and other means, users can also know the occupancy of charging equipment in nearby outlets in advance, and users can easily choose idle charging facilities for charging, which will improve the utilization efficiency of charging facilities while facilitating users. Finally, through networked operation, it is conducive to the establishment of a professional and standardized technical service team, improve the level of technical services, reduce the demand for relevant personnel and equipment, and save social resources.

3 The charging network and the power grid are inseparable

3.1 The charging network has a significant dependence on the distribution network

At present, the subsidy policy issued by the national 4 departments regards plug-in hybrid and pure electric vehicles as the main support objects, requiring the battery capacity of the two to exceed 10 kW·h and 15 kW·h respectively, and the subsidy standard is 3,000 yuan/(kW·h), while the capacity of BYD E6 pure electric vehicle has exceeded 60 kW·h. According to the average capacity of 20 kW·h per vehicle, assuming that fast charging adopts 1-3C charging method (charging time 20~60 min) and slow charging adopts 0.2-0.3C charging method (charging time 3~6 h), the charging power required in the two cases is 20~60 kW and 4~6 kW respectively. In the future, as the battery capacity increases exponentially, its charging power will also need to increase exponentially.

From the perspective of charging facility planning and construction, due to the large charging power and the possibility of harmonic pollution, as the coverage and density of the charging network increase and the large-scale application of fast charging equipment, it is necessary to evaluate the impact of its charging behavior on the power supply reliability and power quality of the distribution network, rectify the charging facilities that do not meet the requirements of relevant technical standards, and the distribution network management department shall implement the necessary distribution network upgrade and transformation projects. Therefore, the construction and optimization layout of the charging network cannot only consider the electricity demand of electric vehicles, but must also be combined with the planning, construction and operation management of the distribution network. The power grid company must master and guide the planning, layout and construction of the charging network. From the perspective of operation and management, the essence of charging facility operation services is to provide electric energy to electric vehicles. Charging stations have an important impact on the safe operation and power quality of the distribution network, and will inevitably be affected by the operation and control of the distribution network. The charging network cannot do without the support of the distribution network in terms of technical services, power metering, electricity bill settlement, and power management.

3.2 The construction and operation of the charging network should be combined with the construction and management of the smart grid.

In addition to meeting the new power demand of electric vehicles, another important benefit of the charging network is to give full play to the energy storage function of electric vehicles. By reasonably arranging the charging time to participate in the peak load regulation of the system, the overall operation efficiency of the power system can be improved, and the huge benefits of energy conservation and emission reduction can be achieved. In the future, with the advancement of battery technology, it is also expected that the function of electric vehicles discharging to the power grid will be realized, further improving their ability to participate in the peak load regulation of the system. To realize the peak load regulation benefits of electric vehicles on the system, it is necessary to combine battery technology research and development, charging network construction, charging service management and smart grid. From the perspective of planning and construction, whether it is invested and constructed by power grid enterprises or other participants, the charging network must be installed with smart energy meters and two-way communication facilities during the construction phase, making it a two-way interactive platform connecting the power grid and electric vehicle users, and making it an important part of the smart grid. From the perspective of operation and management, the charging network operation and management platform must achieve efficient interaction with the smart grid-related management platform. The charging network management platform implements intelligent charging service management based on the power supply and demand situation, real-time electricity prices and other information obtained from the smart grid-related management platform, guides users to charge during low-power periods, and helps the system to peak. In the future, with the advancement of battery technology, it is also possible for electric vehicle users to reversely send electricity to the power grid during peak loads, thereby achieving greater "peak shaving and valley filling" benefits.

In addition, large-scale charging and swapping stations in the future network can also serve as energy storage stations and emergency support power sources. Through intelligent charging management, on the one hand, the impact of electric vehicle charging behavior on the distribution network is minimized, improving the overall efficiency of the system, and on the other hand, the peak-valley electricity price mechanism is used to reduce the user's electricity cost expenditure, achieving a "win-win" situation.

4 Grid companies should play a leading role in the construction and operation of charging networks

Due to the construction and operation characteristics of the charging network itself and its inseparable connection with the power grid, grid companies need to combine their own advantages and characteristics in the construction and operation of charging networks and play a leading role to effectively promote the construction of China's charging network.

4.1 Grid companies have first-mover advantages in technologies and standards related to charging facility construction

Grid companies have carried out a lot of work in the research and practice of electric vehicle charging facilities since 2006, and have achieved many important results. At present, China's grid companies have completed the typical design of charging stations and multiple related enterprise standards, and are actively participating in the research and compilation of national standards; demonstration charging stations and charging piles have been built in Shanghai, Tangshan, Henan, Shenzhen and other places, and grid companies have signed strategic cooperation agreements with local governments, laying a good foundation for large-scale demonstration applications in the next stage. Considering that the construction of charging facilities involves the design and construction of supporting projects such as distribution line transformation and transformer expansion, power quality management technology and intelligent metering technology, grid companies have obvious first-mover advantages in technologies and standards related to charging facility construction.

4.2 Grid companies have network advantages and direct sales advantages in providing charging services

From the perspective of the service network, the charging stations and charging piles to be built in the future are all within the coverage of the power grid. Grid companies can more comprehensively grasp the distribution of charging networks and make targeted and reasonable optimizations. At the same time, relying on the existing distribution network communication information platform and marketing network, power grid companies can more easily realize the network management and service of charging facilities.

From the perspective of sales model, power grid companies directly sell electricity to electric vehicle users without any intermediate links, which not only helps to provide more price-competitive services, but also helps to better grasp and meet user needs.

4.3 Power grid companies can maximize social benefits through intelligent control

Intelligent charging control is the key to achieving the "peak shaving and valley filling" benefits of electric vehicles. It requires the support of intelligent charging management platforms, communication channels, intelligent terminals, and two-way interaction with the power grid. The construction cost and operation and maintenance cost are high. For power grid companies, ensuring safe, economical, clean, and sustainable power supply is their basic mission, and they have the inherent driving force to carry out work related to intelligent charging. In addition, the charging network services provided by power grid companies can use the existing information management platform, communication channels, and smart meter terminals in the smart distribution network to realize intelligent charging control, reduce the construction cost and operation cost of the intelligent charging management system, and maximize the conservation of social resources.

Therefore, power grid companies have both internal motivation and cost advantages in carrying out intelligent charging business and maximizing social benefits.

5 Risks to be prevented in developing charging network business

At present, due to the great uncertainty in the technical route of electric vehicle development, battery technology progress, market acceptance, operation mode and related policies, relevant enterprises in China should strengthen the research on development strategies and pay attention to preventing related risks in developing charging network business.

5.1 Risks caused by uncertainty in technical route and standards

At present, there is still a certain degree of uncertainty in the technical route of electric vehicle development and the relevant standards of charging facilities. For example, the two different technical routes of plug-in hybrid and pure electric have great differences in the demand for charging facilities, and the interface standards and power standards of the charging facilities themselves have a great impact on the construction of charging facilities. It is necessary to guard against the high cost risks brought by adopting too high construction standards, and the renovation and reconstruction risks brought by adopting too low construction standards.

5.2 Risks brought by uncertainty in market acceptance

At present, the electric vehicles used for demonstration and promotion are mainly special vehicles such as buses, taxis, postal services, and sanitation. It is still difficult to judge the future market acceptance of electric vehicles and supporting charging services. Ordinary consumers will have a process from understanding to gradually accepting electric vehicles and their supporting charging services. Therefore, a cautious attitude should be taken towards the construction of charging facilities for private passenger cars. It is necessary to prevent the risk of low utilization efficiency of charging facilities caused by overly radical construction, and to prevent overly conservative construction that cannot meet the requirements of promoting the development of the private electric vehicle market.

5.3 Risks brought by uncertainty in operation model

At present, there is no mature charging service operation model that has been widely recognized. It is necessary to further explore various operation models and their applicable objects, and finally form one or more types of commercial operation models for sustainable development. For example, DC fast charging has a great impact on battery life and is difficult to promote and apply on a large scale; AC slow charging requires good parking garage (space) conditions and is difficult to cover all users; battery replacement technology has the advantages of short battery replacement time and flexible site selection, and has the conditions for large-scale application. It should become the next development focus, but the standardization process of power batteries needs to be accelerated. In addition, since the national and local governments have not yet issued clear policies on the positioning, industry access, and preferential measures of charging networks, the development of related operating models has also brought certain uncertainties. Therefore, we must avoid falling into an operating model with weak sustainable development capabilities.

6 Conclusion

Charging infrastructure is a key link in the industrialization and large-scale development of electric vehicles. There is huge room for future market development. Its basic attributes, construction and operation characteristics determine that charging facilities are closely related to the power grid. The construction and operation of charging networks is not an ordinary fully market-oriented competitive business. The leading role of power grid companies in their construction and operation should be fully utilized, and the government departments, power grid companies, municipal departments, related industries and the public should work together to promote it.

It is recommended that the government and relevant departments actively carry out research on major issues such as charging network service system, business model, and interactive methods, and accelerate the research and formulation of China's charging network development plan and technical standard system.

(1) Further deepen the research on important issues such as charging facility operation and management. On the basis of existing achievements, closely follow the latest development trends abroad, and combine with the actual development needs of China's electric vehicle industry, the government departments, power grid companies and other authoritative research institutions will cooperate to carry out research on China's charging service network development strategy. At the same time, we need to actively organize and carry out special research on the optimization layout of charging networks, service pricing mechanisms, and participation in system peak load regulation.

(2) Focus on formulating the "12th Five-Year Plan" and medium- and long-term plans for charging networks in large and medium-sized cities and strive to include them in local urban development plans. On the basis of the research on the key technologies and standard systems of charging stations (piles), further accelerate the research and formulation of charging network standard systems to effectively support the needs of networking and intensive development of charging infrastructure.

(3) Strengthen publicity and popularization efforts for the public. Strengthen the publicity of the technical, economic and environmental benefits of electric vehicles to the public, and timely publicize the latest progress, relevant laws and regulations, and preferential policies in the construction of charging networks in China. At the same time, we should consider formulating some incentive measures to guide the public to actively use the charging network, obtain public support for the construction and operation of the charging network, and cultivate a good user group to accelerate the construction of the charging network.