Standards Development

Scope

The scope of this technical specification (TS) is the high -level definition of Business Use Cases (BUCs) of flexibility services which are essential for effective network management to maintain stable grid operation in interconnected power systems.

This initiative includes the following four categories:

- Part 1: Frequency Control and Balancing Management (Supply -Demand Issues)

- Part 2: Congestion Management

- Part 3: Voltage Control

- Part 4: Other supportive services (Black Start, Islanding Protection, etc.)

Purpose

The purpose of this TS is to provide a definition of generic BUCs to improve the consistency between the works of TC8/SC8C and those of other TCs, so that the effective integration of flexibility services can be facilitated for the purpose of network manag ement in interconnected power systems.

Historically, power system reliability was maintained by ancillary services procured from large bulk generators like CCGTs. However, such generators are gradually decommissioning, due to the domination of distributed energy resources (DERs), urging system operators to use flexibility services procured from them along with existing generators.

There are three major challenges to meet the above situations:

Firstly, diversity of resource side technology is creating operational complexity. For example, large industrial customers can create relatively big reserves, but often day -ahead or hours-ahead prenotice is required to standby their production lines before the event. On the contrary, battery energy storages system (BESS) can continuously create fast frequency responses, but its energy production capability is constrained by the storage size. Thus, applicable use cases are diversified depending on physical characteristics of resources. Introduction of other types of industries like heat, gas, and mobility into electricity markets is also adding fuel to this kind of complexity. Coordination of different types of technologies is becoming important for many syst em operators.

Secondly, control technology is diversified. Historically, energy management systems (xEMS) have been separately developed in different industries, with limited coordination with system operators. The protocols used in such systems are sometimes non -IEC or even proprietary ones. Moreover, it is often the case with systems manufactured in one country is used in other countries without any localization even though difference of market structure exists, which hinders the smooth integration of resources with potentials to provide flexibility services. Also, we must take notice that there are some other types of resources which do not use communication signals. For example, inertial support from rotating machines, grid foaming inverters (GFM) can offer stabilizat ion services by on- site controllers without any dispatch instructions. They should be quantitatively assessed by grid operators or utilities to ensure the system security of interconnected power systems.

Thirdly, temporal, and spatial dynamics exist. There are some types of resources like electric vehicles, whose charging time and location can be flexibly controlled by consumer’s discretion. This is meaning that consumers’ behaviour directly affects the sy stem operational performance and creating uncertainty. To cope with this situation, design of proper price signals to incentivise them to alleviate network stress is a major concern in many countries. After a large integration of RESs, it is becoming necessary for many SOs to ensure the real-time preparedness to cope with the dynamic network conditions.

Consequently, the proposed BUCs can share a common view of minimum set of generic operational approaches so that it would serve as a guideline before elaborating standards for specific component elements to ensure interoperability in each field. For this p urpose, four major domains have been identified including frequency management, congestion management, voltage support, and other services.

Justification:

This initiative handles operational issues concerning “Network Management in Interconnected Power Systems”, which is consistent with the SBP of SC8C especially stipulating the following items:

-Guidelines for network design, planning, operation, control, and market integration

-Functional and technical requirements of energy, ancillary service, and capacity markets

-Technical requirements of wide-area operation, such as balancing reserve sharing, emergency power wheeling.

This NP is related with IEC63530 “Market Catalogue for Stable Grid Operation” as a series of effort. 

Also, it is following a philosophy of IEC White Paper, "Stable grid operations in a future of distributed electric power”, issued in 2018, calling for “creation of common language” for newly participating DERs.

To clarify the mission, items outside the scope of this initiative are: (1) political or regulatory items which creates regional diversity, (2) system use cases (SUCs) which should be discussed in TC57 or other TCs, and (3) terminology works which are not the main focus of this initiative (the coordination with TC8/JWG1 is considered during the work when necessary).