School of Engineering

Protecting power networks against failure

Our pioneering monitoring and innovative measurement techniques for overvoltage transients and protection have been included in international electrical standards and technical guidelines on best practices.

Image credit: Electrical Engineering Portal.

Voltage surges on electrical networks can be caused by events such as lightning strikes, and system switching manoeuvres and faults. When an overvoltage occurs, it can cause catastrophic failure if not mitigated, leading to dangerous working environments, substantial damage to infrastructure, and even blackouts. The cost of power failures is immense and can lead up to millions of pounds of economic losses, wide-reaching effects, and even endanger the life of workers and the general public.

Research from the School of Engineering has helped to address the problem by developing new techniques for monitoring and transient measurements on the power network, that have defined best practices in international standards for overvoltage protection.

Our solutions have been adopted by leading companies, including Tata Steel and the National Grid, resulting in safer working policies, more effective protection and more reliable networks while saving costs.

Protecting critical infrastructure

On the basis of a longstanding partnership with the School of Engineering, the National Grid Electricity Transmission company has changed multiple policies and practices that affect electrical networks across the UK.

Our work has led to the creation of safer working policies and more effective protection of critical infrastructure, resulting in annual savings of £220,000 and improved performance.

Our researchers have also worked with Tata Steel to investigate the source of substation flashover events at the UK’s largest steelworks. Tata Steel applied Cardiff-designed mitigation to eliminate flashover events at their Port Talbot steelworks, resulting in savings of £9.6 million.

Enhancing overvoltage protection

The Cardiff University Advanced High Voltage Engineering Research Centre (AHIVES), led by Professor Abderrahmane Haddad, has been central to developing an understanding of electrical networks, addressing insulation reliability and optimising overvoltage protection.

Overvoltage protection is set to change in many countries as a result of the work completed by AHIVES. The International Electrotechnical Commission published a major update in May 2013, on the international standard for the selection and application of surge arresters and included methods developed by Professor Haddad to monitor surge arresters when protecting high-voltage substation equipment.

The standard was further updated and republished in January 2018, with Professor Haddad’s methods continuing to be cited, and was adopted into national standards by IEC member states in March 2018.

Alongside the published global best practice, the International Electrotechnical Commission for Standardization approved the revised international standard, and all member nations have adopted the update into their own national standard.

Mitigating the harm of insulation gases

Sulphur hexafluoride provides excellent insulation for gas insulated substations. However, it is extremely harmful to the environment with a global warming potential of 23,500 times that of CO₂.

Researchers from the School of Engineering collaborated with the National Grid to identify practical SF6 replacements. Our research was adopted by the National Grid, setting the strategic direction for eliminating these greenhouse gases.