CEMS as a Smart Grid Infrastructure

to electric power industry. Table 2-6 shows some applicable areas of the ad-hoc technology.

In order to realize Smart Grid, it is essential to utilize various kinds of information in addition to electric power related information. Network in various industries are constructed and the interconnection of these networks realize various and enormous data collection and these data should contribute to the realization of high accuracy EMAs and EMSs.

Table 2-6 Ad-hoc Technology Applicable Areas

Industry Support Area Collection Data

Agriculture Work Schedule,

Status Confirmation Temperature, Moisture, Illuminance Soil component etc.

Process Industry Operation Management

Maintenance Support Operation status, consumables, firmware version etc.

Beverage Sales Planning

Delivery Order Merchandise Inventory, change, sales status etc.

Logistics Traffic Support

Delivery Status Location information, Engine rotation etc.

Utility Metering Support

Demand Control Consumption, Supply and demand balancing.

Forecast accurate amount of power supply and demand in each calculation time frame

Develop optimized target power supply and demand plans Shift power demand targeting for the developed demand plans Supply power corresponding to the developed supply plans

Table 2-7 CEMS Required Functions

Also the following monitoring and control features are required once optimized power supply and demand plan is determined.

Category Function

Group Functions Function Outline

Forecasting and Planning

Supply and Demand Forecasting

Forecast

(Total generation, Total demand, Response rate (Recommendation) Data Interface

(Control center, Power exchange (PX), Weather information, Other EMSs etc.)

Frequent and Rapid Forecast -Total power supply amount by

both utilities and dispersed generation assets

-Total demand

-Branch level supply and demand forecast considering photovoltaic (PV), EV and battery installation.

Variation Forecast Supply and

Demand Balancing

DR and DSM Program Development

Generation Dispatch Notification

PV(Power Conditioning System (PCS)) Battery, EV charge, charging, Data Interface

Power flow calculation

Power Demand Control by DR and DSMRenewable Energy Prioritization by the Movement of Decarbonizing Local Production for Local Consumption in Electric Power - For disaster resilient power

systems Supply and

Demand Scheduling

DR and DSM Recommendation provision

Generation Dispatch Notification

PV(PCS), Battery, EV Data Interface

Power Flow Calculation

Demand Shift for Achievement of Target Demand plan

(e.g. Optimized operation program provision for each device, PV disconnect from the system for stable power supply etc.) Consumer Voluntary Demand Reduction (e.g. TOU provision, etc.) Monitoring

and Control Equipment

Monitoring Real-time System Situation Monitoring Real-time System Status Monitoring

Backup Generation Monitoring

Existing Supply Equipment Monitoring

Power Supply Equipment Monitoring in Demand-side Data Storage for Future Advanced Equipment Control

Equipment

Control Control Message Transformation Interface Existing Process Computers

Developed Schedule Reflection to Existing Power Supply Equipment.

Disconnection of Demand-side DG, battery etc. from Power Systems Operation Support for Reserve Generations

Monitor power supply and consumption equipment status

Control power supply and demand equipment for the achievement of optimized targeted power supply and demand plan

Table 2-7 shows detailed description of above mentioned features in CEMS.

Technologies Required to Provide CEMS Functions (2)

In order to realize above mentioned CEMS functions, various advanced technologies are required to execute enormous data high speed processing because of dealing with a large amount of distribution assets and residential equipment data. Here, some applicable technologies are introduced.

a. Advanced Technical Calculation

Power flow calculation and optimization are essential measures to estimate power supply and demand amount and to create efficient power supply plans. Although various power flow calculation methods has been studied, one of the main objectives of the CEMS should be to provide rapid calculation algorithm for the environment that many DGs (mainly PV generation) are installed and a lot of information can be collected and processed, considering the power supply environment in the near future in Japan.

Therefore, it is expected that power flow calculation method can deal with a lot of DGs as well as a large number of power consumers (load points) and can set various optional attributes. This means the power flow calculation need to deal with enormous data incomparably larger than ever before, so it is required to have a rapid processing algorithm.

b. Enormous Information Collection and Delivery

Because many and high density PVs installation might influence power stability by reverse power flows, voltage sags or voltage rises etc., some functions are required to monitor power system situation and status information, and execute adequate actions to avoid instability statuses. Therefore, it is assumed that the CEMS needs to collect (or calculate) power status data such as voltage and current. Also, data from RES generation in demand-side should be all collected, as well as data from reserved generations for back-up and other related equipment. These data would be integrated and processed to create optimized operation programs in CEMS and these programs reflect to the targeted equipment.

Furthermore, metering data from AMI, process data from supervisory control and data acquisition (SCADA), distribution management system (DMS) and other related data such as weather and PX data etc., are assumed to be integrated in CEMS, and these data and calculation results should be utilized for the improvement of optimized programs calculated by EMAs.

c. High Speed Data Processing

The CEMS is required to process huge power supply and demand related data and provide optimized operation plans rapidly. Therefore, high speed mechanisms from the viewpoint of information processing should be adopted, as well as consideration of high speed algorithm or processing logics. In the baseline of the CEMS concept, the application of the complex event processing (CEP), in-memory database and the key value store (KVS) has been studied to meet data process requirements as Smart Grid information infrastructure. Table 2-8 shows outline of these technologies and examples of their adopted area in CEMS.

Table 2-8 Rapid Data Processing Methods in CEMS

Adopted Technology Description Adopted Area

CEP

(Complex Event Processing)

Rule based data processing by judgment of monitoring event context

Real-time system

information visualization In Memory Database Database management system of

on-memory data storage

Power Flow calculation KVS

(Key Value Store)

Simple and rapid data storage method by Key and Value

System asset management

Figure 2-8 shows the holistic overview diagram of CEMS concept. Various information from supply and demand sides, other organizations such as service provides, PX etc., are gathered using various networks. Data collection/delivery interfaces interpret data property and transfer the data to CEP. In the CEP, the data are distributed to adequate processing units or data storages using scenarios stored in the CEP. Processed data by the above mentioned rapid data processing method are returned to supply and demand equipment for optimal control and/or returned to operators and consumers for the optimal energy management.

Figure 2-8 Supply-side EMS Concept Overview

Key Technical Research Topics for Realizing Smart Grid 2.5.

At the end of this chapter, key technical research topics are described and research directions and expectations are defined. Here, it is necessary to clarify for whom these research topics would be conducted because benefit or profit, focused in this study, depend on the position of entrants in power markets. Therefore, the position of beneficiaries in this study is also clarified.

2.5.1.Key Research Topics

Key technical research topics including concrete challenges for selected ICT contribution topics are described for the critical areas of Smart Grid realization selected in 2.2.

Optimal Power Supply (1)

In this category, main research topic is optimal installation of distributed equipment such as DG for efficient and reliable power supply. The major purposes of this topic are cost and power loss reduction by locating generators near demand, RES increase for the reduction of CO2emission and quick power supply recovery from a disaster.

Optimal Power Utilization (2)

In this category, major research topics should be to provide effective demand-side EMSs for optimal energy utilization and to develop effective price programs including DR for optimal power companies operation. In order to provide both effective EMS and price programs provision including DR, control methods of or appliances should be considered and clarified.

Optimal Power Supply and Demand Control (3)

In this category, the most critical challenge is to maintain reliability of the future advanced power systems considering a large number of RES generation connected environments, including power supply and demand balancing, voltage and current management, and outage management in a target system using both supply and demand sides information.

From above considerations, Table 2-9 describes ICT contribution topics for critical technological measures to realize Smart Grid. Therefore this study defines that Smart Grid

the expansion of ICT application to these technologies should accelerate the realization.

Table 2-9 ICT Contribution Topics for Critical Technological Measures for Smart Grid

Category ICT Contribution Topics

Optimal Power

Supply Optimal asset installation for efficient power supply, such as DG etc.

- Optimal allocation of DG, SVR and SVC - Benefit and cost evaluation of RES Optimal Power

Utilization Benefit realization of demand control measures such as efficiency energy consumption (Consumer EMS) and various price program

- Benefit and cost evaluation by demand-side EMSs

- Benefit and cost evaluation by power companies price programs including DR

Optimal Power Supply and Demand Control

Effective methods to maintain power supply reliability in a targeted area

- State monitoring for distribution system with a large number of PVs - Outage management for smart meter installed environment