2005-03-15 - ABB’s WAMS technology was recognised in 2003 by the Massachusetts Institute of Technology (MIT) in the US as one of the top 10 emerging technologies that can change the world.
ABB’s wide area monitoring system (WAMS) technology uses GPS satellite signals to accurately measure and analyse the condition of power grids and detect system instabilities as they appear. Large power outages are usually the result of multiple system failures that happen within minutes, and sometimes in seconds.
WAMS uses the satellite signals to ensure that the phasor measurement units which monitor the condition of the power grid are synchronised with an accuracy of one millisecond. This enables system dynamics, such as frequency, voltage and power oscillations, to be observed in real time regardless of the large geographical distances between measurement points and provides valuable early warning of potential network stresses.
It became the first commercially operative wide area grid monitoring system in Europe during summer 2004 when it was installed by Swiss energy company, ETRANS, in the critical Swiss north-south transmission corridor. The ABB technology is helping keep the power flowing from Switzerland to Italy by faster detection of critical operating conditions.
Precise, synchronised measurements
The monitoring and control systems of individual utilities gather information from sensors within their own grid, and then evaluate this information to determine whether their system is operating to deliver the power to meet demand conditions. When things go wrong, the system either reacts automatically to take contingency actions, or displays information that allows system operators to take action.
Using the component PSGuard, ABB’s wide area monitoring system gathers and analyses system data in milliseconds, compared to every two to five seconds in conventional network control systems.
This means emerging network problems, like shifts in frequency, can be documented and even predicted because precise and synchronised measurements can be taken consistently across the grid. Operators can also detect emerging problems in a neighbouring grid before they build up, allowing them to take preventative action.
Wide area measurement systems
A typical wide area measurement or WAMS system is built up on a reliable communication system connecting power stations, network control centres and sub stations. The GPS satellite system is used for timing accuracy and a number of phasor measurement units are deployed across the power network.
The phasor measurement unit or PMU streams the required real time data through the communication link to the WAMS. In some cases, PMUs could even include local instability protection schemes. To achieve value from the accurate and reliable data streams coming from these PMU devices, ABB has now introduced the PSGuard wide area measurement system.
The PSGuard system is a scaleable solution that can be implemented in stages, paving the way towards automatic wide area measurements by transmission companies. Application functionality packages can be chosen and implemented based on utility needs with the system being built on standard PC hardware and operating systems and having the required security standards built in.
Company background
ABB (www.abb.com) is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 103,000 people.