Power grids and the importance of standards and grid codes

The distributed renewable energy sources in power grids are steadily increasing - a smarter, more diverse and robust electricity infrastructure is necessary

The national electric power grid system was built up over a period of more than 100 years, and today it forms one of the most effective components of the infrastructure on which modern society depends on. Power grids are composed of transmission and distribution lines, substations, transformers and a variety of other components that deliver electricity from power plants to industry, commercial and residential consumers, meeting ever-growing power demands.

Today, power grids throughout the world are going through a period of unprecedented change. Penetration of utility-scale wind power in power grids continued to increase in 2015, bringing total installed wind power capacity to more than 431 GW – which is equivalent to over 500 modern nuclear power plants.

With utility-scale wind power and other distributed renewables interconnected in national grids, there is a growing need to upgrade and modernize existing transmission and distribution systems. At the same time, revising international standards and national grid code requirements is necessary in order to enable a smarter, more diverse and robust electricity infrastructure.

Standards and grid codes ensure stability and safety

There are standards for almost everything we use and do every day. It is only through standards that the requirements of interconnectivity and interoperability between new and existing products, services and processes can be assured. The most important standards are the ones issued by the International Organization for Standardization (ISO), International Electrotechnical Commission (IEC), Standardization Administration of the People’s Republic of China (SAC) and the Institute of Electrical and Electronics Engineers (IEEE). Other national standards are, of course, no less important but they are often adaptations of standards issued by these key organizations.

Power grids are regulated by standards and grid codes, which seek to ensure the stable and safe operation of the network by defining the main factors that have to be taken into account when connecting any kind of power generation plant to the grid.

Grid codes are also known as ‘interconnecting guidelines’. They specify requirements for the technical and operational characteristics of power generation plants, such as wind farms, and for different parties involved in the production, transportation and utilization of electric power. Grid codes address all significant concerns associated with the power grid and guarantee its safe operation and performance. Because utility-scale wind farms can replace conventional power plants, wind farms are expected to support power grids and provide ancillary services similar to conventional power plants.

Grid codes are mainly concerned with transmission system voltage and frequency variations, fault events, reactive power capabilities, safety, and security. Requirements are typically defined at the point where a wind park is connected to the grid (point of common coupling), but can sometimes also be defined at the point where a single wind turbine is connected to the grid (point of connection). In the wind industry, the most demanding requirements are generally considered to be those in force in Germany (VDE-AR-N 4120), the UK (The Grid Code), Europe – the European Network of Transmission System Operators for Electricity, ENTSOE (NC RfG), China (GB) and the US (FERC, NERC).

New requirements to be considered in future regulation

With the increase in renewable energy being fed into the grid, there is a need for standards and grid codes to be revised to meet the new requirements. It is important for plant operators and component suppliers to be informed about developments and new trends. Only then they can ensure that their plants – and all plant components – comply with the relevant standards and grid codes.

In our next blog we’ll provide a short overview of current developments and what impact they might have on future regulations. Please stay tuned or meet us at upcoming events like China Wind Power, which will be held on October 19-21, 2016 in Beijing. We look forward to discussing with you how ABB can help you achieve a better wind economy for your wind farm.