Construction of China's smart grid information system analysis

Abstract

The start of the smart grid program will drive significant changes of grid operation, management, customer service and social energy use patterns. Informatization as the Smart Grid “four modernizations” breakthrough feature, its importance is distinguished. The important feature, trends, construction direction of smart grid informatization will be the power companies and the IT industry issues of common concern. This article outline the construction contents of smart grid and analysis the informatization technology position in the smart grid and demand for informatization of smart grid construction. And on this basis, analyze the smart grid informatization construction system, and shows the contents of informatization construction from three different dimensionalities: the information hierarchy, power industry chain and business type. Finally, describe the contents of informatization construction and business application from five dimensionalities: data collection layer, data transmission layer, data analysis layer, information integration layer, and information showing layer.

Introduction

The core content of smart grid is establish open system and shared information model, integrate system data, and optimize the grid management by introducing communication, automatic control and other information technology with advanced computer, electronic equipment, intelligent components, etc. Thus form a network interactive and instant connection between users and users and grid companies, and realize reading data real-time, two-way and efficient, which will greatly enhance the interactive operation of power grid and improve the overall power grid reliability and efficiency.

Smart grid is an integration of most advanced communication, IT, new energy, new material, new equipment, etc. It will concentrate the essence of world technological revolution for social services directly, open a new era of power industry management and promote the revolutionary power infrastructure upgrade. In the power supply side, smart grid can support diversified power supply and change the traditional single centralized power mode, which will convenient various grid merge into and realize reliable consumptive. In the grid side, the grid operation will realize visualization, digital and intelligent; power grid enterprise will greatly enhance the level of integrated services about planning, scheduling, trading, producing and so on, and to achieve effective integration, the formation of smart grid. In the electricity customers’ side, users can make two-way communication with the smart grid; according to grid information and user needs run real-time adjustment and provide efficient quality services. In the whole power system level, based on the extensive collection of information and timely delivery, through relevant regional, business and users and achieve full coordination between each other. Therefore, informatization construction system of smart grid is the key and the essence of smart grid construction system [1].

Construction of smart grid will cover power supply, power transmission, power substation, power transforming and power selling the entire business value chain, while achieving unified integration of power flow, power grid enterprise business flow and information flow.

One of the advantages of smart grid is compatibility, that is supporting centralized access of big power, also can access more distributed clean energy, such as photovoltaic generation, wind power, hydropower and so on. Gridconnected operation of distributed power puts forward new requirement about power flow control of distribution network. Smart grid will provide new protection scheme, voltage control technology and instrument to satisfy two-way tide need. The meanwhile access of concentrated and distributed energy will improve power system's reliability and efficiency, provide support for peak load of power grid; at the same time, when the big grid damaged, these distributed power can form island or microgrid voluntarily and provide emergency services for hospital, transport hub, broadcast television and other important users [2].

State Grid Corporation of China proposes that build a strong smart grid which use UHV power grid as the backbone grid and various power grid coordinated growth in an all-round way is a smart grid construction goal which fits China's national conditions. Through a united, common platform on power to conduct a comprehensive coordination, planning and running. With the large energy base to rely on, construct UHV grid consisting 100 kV ac and ±800 kV, ±1000 dc, form the power “expressway”, promoting the intensive development of large coal, large hydropower, large nuclear power and large renewable energy base and realizing the optimum distribution of resources on a national wide. At the same time, guarantee the grid stability under in the long distances and big load transmission cases by senior dispatching center construction, big grid operation control technology and flexible transmission and other smart grid technologies and equipment research.

Compared with power transmission grid, the flexibility, automation analysis and control level of distribution grid insufficient still. Advanced distribution automation construction will be the important component part of smart grid. Advanced distribution automation will contain system's monitor and control and distribution system management functions and integration with the user, realizing load management and electricity real-time pricing. Through coordinated operation with the other component parts of the smart grid, distribution automation not only can improve system monitor, reactive power and voltage management, decrease the line loss and increase asset utilization rate, but also assist optimizing personnel dispatch, maintenance operation arrange and so on [3].

In the current grid equipment, in addition to some second equipment can realize remote operation, most of the power equipment between information transmission is basically unidirectional way, while future smart grid will form a new communication and interaction mechanism realizing information interaction between grid equipments, based on which will greatly increase grid intelligent. By using the interaction of the smart grid, can realize two-way data transmission, carry out floating price system of dynamic, using senor make real-time monitoring the running state of generating power, transmitting power, distributing power, supplying power and other key equipment, when meet the power supply peak, can scheduling in different zones, balancing power supply shortage, so as to achieve optimization of the entire power system operation management and improve the stability and reliability of the grid operation.

Perfect smart grid need construct grid real-time monitor system covering power generation, transmission grid and distribution grid, which can realize real-time (second to millisecond delay) comprehensive view of grid and monitor the operation of the grid through sensor. Through build power sensor system and update power system automatic control system, power performance information can provide automatic, near real-time power grid control and solve safe operation problems of the prediction, detection, and repair the power system by integrated SCADA system. Thus can find the default as soon as possible and take proper measures to quickly isolate the problem to avoid costly power outages, ensure safety and electricity grid reliability and realize grid self-healing function by perfect smart grid monitoring and controlling. Management system efficiency is getting more and more complicated, this need decentralized decision-making mechanism to be integrated, and that is smart integrated into the grid. Thereby can realize the optimization of power grid management and greatly reduce power outages [4].

Smart grid is different from the traditional grid another feature is “interaction”, that is can make two-way interaction with the terminal power user. Obtaining the optimal program for electricity will change the existing electricity behavior and improve customer satisfaction. The basic demand of making two-way interaction with the terminal power user is grid enterprises can real-time collecting and tracking power information of customers, control the load, analysis and take the most economic, stable power supply scheme; at the same time, terminal equipment can transmit time prices, electricity quantity and other information to users. Therefore, in smart grid construction, the application of smart mitering device will become the basic device to achieve interaction between the two sides. Through smart mitering device, power supply enterprises can realize real-time collecting user's information and with smart mitering device integrated management software can obtain and analysis this data, master the load information and mediate power distribution. According to the power information, power supply enterprises can calculate time prices, predict price trend and mediate power scheme by user terminal smart appliances.