1 2 3 4 5 6 7 8 91011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556576061

Research on Smart Distribution Network System Architecture

Xu Xiao-hui, Zhai Chang-guo Electric Power Research Institute,

Nanjing Jiangsu, China

Chen Li-juan Southeast University

Nanjing Jiangsu, China

Chen Dong-lei, Yang Yong-biao Electric Power Research Institute

Nanjing Jiangsu, China

Abstract—Smart distribution network involves distributed

generation, micro-grid, electric vehicles, energy storage and other new elements. Besides it has characteristics of bidirectional

interactive, network self-healing, power quality improvement, protection of reliability of power supply, elimination on the spot

of distributed clean energy and so on. It is currently an important and popular research focus of smart grid. In this paper smart distribution network system architecture was

introduced from four aspects, which include planning, operation, management, and integrated application, then different construction modes of smart distribution network were

proposed. Finally, the evaluation indicator and methods for smart distribution network construction were discussed.

Key word- Smart grid; Smart distribution network; System architecture

I. INTRODUCTION

Along with the development of distributed generation, micro-grid, and electric vehicles etc. Also, the traditional distribution network which including supply-side driven, single power supply, one-way service and basic reliance on manual management of business model turns into the direction of user interaction, the trend of two-way flow, and highly automated, and these changes gradually formed the smart distribution network system architecture. However, smart distribution network involving many varities of business and type of complex, conventional distribution network business architecture and technology system has been difficult to adapt. It has a very important practical significance for re-sorting smart distribution network and related technology, establishing the requirements of smart grid technology system, effectively providing efficiency of distribution network assets and reducing labor costs.

U.S. EPRI launches smart grid research project IntelliGrid[1-3], which has two aims: 1) Power system function: needs analysis of power system operation, including present and future needs, such as: self-healing grid. 2) Smart grid architecture: based on the above needs analysis, information acquisition sysytem of future power system is proposed, and then the long-term architecture is established. The project provides a clear link between the relationship of the information requirement of power system function and IntelliGrid system. In addition, U.S. EPRI carries out the

research on an integrated system of energy and communication system project which named IECSA [4-7]. IECSA is the first step to promote IntelliGrid, and to integrate two different systems: physical energy delivery system and intelligent communication network equipment for its control. U.S. Department of Energy has also proposed a Modern Grid concept, it including these six parts: establishment of Modern Grid, gap analysis, identify needs, pilot project, project evaluation and stimulate the deployment. In Europe, the future electricity network technology platform Advisory Board released a vision of smart grid projects in Europe [8-10]. In this vision, the future of the electricity market and network must be able to provide users with a reliable, flexible, accessible and low-cost power supply system.

China has carried out some researches on smart distribution network [11-13]. Shanxi Province Power Corporation creates a “multi-index from the near-optimal” smart grid theory, to optimize the energy flow through the value chain as a fundamental goal, through the establishment of the methodology, strategic indicators and process indicators of building, the proposed calculation and assessment methods, etc. It forms a comprehensive and complete set of smart distribution network indicators. Liu Dong form Shanghai Jiaotong University, analyzed characteristics of energy flow, information flow and business flow in three different stages of development of traditional distribution network, digital distribution network and smart distribution network. It gave the five key characteristics (self-healing, interactive, optimization, compatibility and integration) and six research areas of smart distribution network. SGCC launched the ‘Strong and Smart Grid Comprehensive study’ research, it made the detailed description of requirements, new technology application and demonstration projects of major aspects of power supply, transmission, distribution, using, scheduling and information communication in smart power grid. And it developed the power system of strategic research topics for SGCC and has achieved fruitful results. However, there has not been clear of the relationship between systems involved in the smart distribution network system, and the description of overall system architecture and technology roadmap was not sufficient.

From all above: at home and abroad carries out an amount of research in various aspects of the smart grid. But in the smart distribution network system, business functions and achieve mode need to be future in-depth, much-needed put

IEEE PES ISGT ASIA 2012 1569534581

1

1 2 3 4 5 6 7 8 91011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556576061

forward for smart distribution network technology roadmap, in order to guide the company’s research and development work in power grid .

II. SMART DISTRIBUTION NETWORK SYSTEM

ARCHITECTURE

Figure 1 shows the research ideal of smart distribution network system architecture. Firstly, study the system content. Then establish the framework. Finally, study the implementation mode.

Figure 1 research ideal of smart distribution network system

architecture

The demands of the smart distribution network are analyzed from four aspects: planning, management, operation and application, which are shown in Figure 2. According to requirements, the present situation is analyzed, and the differences between requirements and present situation are pointed out. Then, from the difference, the solutions of the distribution network architecture are found gradually. In this part, Planning includes: power planning, grid planning, load forecasting, DG accessing plan, evaluation of distribution, and planning methods and software support, etc. Operation includes: distribution automation, distribution equipment, PQ monitoring, DG/MG access, EV equipment access, etc. Management includes: condition based maintenance, live working, standardization of repair, and asset life cycle management, etc. Application includes: GIS, comprehensive test for detection support platform, etc.

Figure 2 the content of smart distribution network system architecture Then, according to the above four modules, analyze the

specific content of each module. the content should be related to businesses that are already existed, ongoing, or after 5-10

years. Finally, get the architecture of smart distribution network, initially shown in Fig. 3.

Figure 3 smart distribution network system architecture

Smart power consumption system architecture is based on the general framework of the solid foundation of smart grid, standards and intelligent power management and key technical services and equipment for the strong support for communication and security systems for the reliable guarantee to intelligent power of information sharing platform for information exchange channels , through the intelligent use of electricity services, technical support services platforms and intelligent use of electricity interactive platform for electricity customers with intelligent, diverse electricity services, and electricity customers to achieve energy flow, information flow, business flow of friendly interaction, enhance the quality and level of customer service. The contents of the smart electricity system are shown below. It includes common power consumption service, new energy service and novel user service.

EV operation and

management

Conventional marketing services

New customer services

New energy services

Human Resources

Project management

External units

Materialsmanagement

Coordination office

Low-voltage DG access

Energy metering and information

collection

Electricity management

Energy efficiency service

Fiber to the home

Market and demand-side

Customer service and customer

relations

Customer interactive

Interaction of Business

hall

Integrated management

EV charging facilities

Low-voltage micro-grid access

……

Low-voltage energy storage

access

Figure 4 the content of smart power consumption system architecture

The smart power consumption system relates to the intelligent management of distributed power, electric vehicles

2

1 2 3 4 5 6 7 8 91011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556576061

and intelligent storage management, intelligent use of energy services and energy efficiency diagnostics, intelligent two-way interactive services, customer resource development and utilization of intelligent measurement and control, intelligent marketing, business management and decision-making and other aspects, as shown below .

Strong and smart distribution network

Communication and security system

Interactive platform for Smart power consumption services

Customer energy Service system

Power consumption informationCollection system

ChargingAnd

Storage SystemAccess

Management

Access Management

DGsystem

SmartMeasurementManagement

system

Marking and Management

system

Electricpower

GeographicInformation

system

Aided analysis and decision-making system

Customers

Information-sharing platform for power consumption

Technical support platform for smartpower consumption services

Org

anization m

anag

ement an

d stan

dard

system

for sm

art pow

er consu

mp

tion

Key tech

nolo

gy an

d eq

uip

men

t for sm

art po

wer co

nsum

ptio

n

Figure 5 the architecture of smart power consumption system

The smart distribution network involved with multiple systems, such as distribution automation, SCADA, production management, asset management, the power consumption information acquisition, energy services, intelligent measurement management systems, distributed generation management system, charging and discharging and storage management systems, marketing services, and other geographic information systems. The paper considers the following aspects of the business across systems to achieve: 1) Accordance with the provisions of the security methods

to achieve cross- system security. 2) Cross-system business integration. 3) The system data requirements of business functions. 4) Data exchange of system business functions.

To meet the requirements of information exchange with the power and data communication method, on needs to analyze the requirements of communication and information for the future intelligent power distribution network. Way of using information to build the bus to meet the requirements of information exchange distribution method is shown below. The IEB-based information integration bus realizes data exchange based on common information model (CIM). It provides an efficient method for data exchange between different languages and software technologies.

Information exchange bus（ IEB）

MIS DMSDistributi

on GISEMS

Management

database

Real time database

Distribution GIS

database

Customer database

……

……

Figure 6 the data interactive method for distribution based on IEB bus

III. APPLICATION MODE OF SMART DISTRIBUTION

NETWORK

The typical application mode of smart distribution network can be considered from region. Considered the requirement of three integration and five big systems of SGCC, the mode of city-level smart distribution network can be constructed by the separate construction of smart power distribution system and the smart power consumption system. The interaction of the two systems is achieved by the integration of the data and information, shown in Fig. 7.

Figure 7 achieve mode of power distribution system for prefecture-

level city

For country-level areas, the unified construction of smart distribution network system can be considered. Unified platform for data acquisition and information support is established, and based on the platform, various business and advanced application analysis are developed,

3

1 2 3 4 5 6 7 8 91011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556576061

as shown in Fig. 8.

Figure 8 achieve mode of power distribution system for country-level

areas

IV. EVALUATION METHODS FOR SMART DISTRIBUTION

NETWORK CONSTRUCTION

TABLE I evaluation system for smart distribution network technology

Characteristics Evaluation

Safe and reliable

N-1rate Attack against the war, terrorist attacks and natural

disasters, avoid blackouts, removal of fault area, ensure non-fault zone

Power supply reliability rate Momentary power interruption（times／year）

Fault healing and fault warning

Flexible

Access to new energy sources ( wind and PV storage) Access to distributed generation

Access to micro-grid Supply voltage passing rate

Harmonic is lower than national standard Minimize the voltage drop

Quality Supply voltage passing rate

Harmonic is lower than national standard Minimize the voltage drop

Cost-effective

Summer peak load case rate of medium voltage distribution network capacity

Maximum rate of peak load power Comprehensive line loss rate

Increase the average load rate of power supply equipment Reduce the line loss rate

Troubleshooting time Improve the level automation

Smart

Proportion of information Operating with integration system

Automatic generation of auxiliary power supply options Proportion of distribution automation to achieve

Build aided design, support planning, economic operation decision support system for distribution network

The rate of interaction with large customers, the general rate of interaction

TABLE I summarizes the characteristics of smart distribution network from five aspects. And a certain description for each characteristic is given. Then, the evaluation indicators and methods of smart distribution network are gradually completed.

V. CONCLUSION

In this paper, the content of smart distribution network system architecture is put forward from four parts: the planning, operation, management, and application. Then, the corresponding architecture is established, and two different application modes for city-level and country-level are given. Finally, the evaluation indicators and methods for smart distribution grid system construction are pointed out. The research results have a certain significance for Chinese smart distribution network construction.

REFERENCES [1] EPRI, IntelliGrid Consumer Portal Frequently Asked Questions and

Survey. 2005. [2] EPRI, IntelliGrid Architecture Application Guide: Metering and

Consumer Systems. 2006. [3] EPRI, Intelligrid Integration of Metering Objects for Customer

Communication. 2006. [4] EPRI, The Integrated energy and communication systems

architecture: Volume II: Functional requirement. 2003, Electric Power Research Institute: Palo Alto, CA.

[5] EPRI, The Integrated Energy and Communication Systems Architecture, Volume I: User Guidelines and Recommendations. 2003, Electric Power Research Institute.

[6] EPRI, The Integrated Energy and Communication Systems Architecture, Volume III: Models. 2003, Electric Power Research Institute.

[7] EPRI, The Integrated Energy and Communication Systems Architecture, Volume IV: Technical Analysis. 2003, Electric Power Research Institute.

[8] A European Strategy for Sustainable，Competitive and Secure Energy. 2006.

[9] Vision and Strategy for Europe's Electricity Networks of the Future 2006, the Advisory Council of the Technology Platform of Future Electricity Networks.

[10] Smart Grids: Building a Strategic Technology Roadmap. 2008,（UTC）.

[11] .2008, IBM whitepaper – smart grid construction. IBM. [12] Cisco, Cisco whitepaper – smart gird. 2008. [13] SGCC, Research paper of smart grid, 2009.

4