DIGITISING FOR AN OPTIMISED , ENVIRONMENTALLY FRIENDLY GRID
By Vladimir Milovanovic , vice president , Power Systems , Energy Management Business , Schneider Electric
The ripple effect of South Africa ’ s loadshedding is well publicised , impacting the entire user lifecycle , from large conglomerates to our own homes . Sadly , loadshedding has the potential to not only impact the productivity and income of the consumers , but also the very system that provides us with power .
Equipment residing in sub-stations and distribution centres , new or old , is not designed to withstand an onslaught of surges , continued interruptions , and on / off switching multiple times a day .
One example is medium voltage ( MV ) switchgear that has been designed , in optimal circumstances , to last up to 40 years . However , as mentioned , no equipment can handle the extraordinary circumstances that come with loadshedding , which means switchgear and other equipment simply stop working well before their projected End-of-Life ( EOL ).
In the case of gas insulated switchgear ( GIS ), how SF6 is collected and recycled at its EOL is a major priority . Furthermore , with pure-air insulated switchgear now becoming available , there is a compelling case for replacing faulty equipment with SF6-free options .
SF6-free MV switchgear is a viable choice not only for the environment , but also for operational safety . Additionally , it offers ease-of-maintenance , EOL treatment , functionality and performance as well as environmental compliance .
Pure Air switchgear is natively connectable , which means new equipment can be added with minimum disruption . SF6-free switchgear is also designed in such a way that it does not require operator retraining , thus mitigating downtime , and importantly , if there is a gas leak the pure air will simply escape into the atmosphere , causing no environmental impact .
Maintaining a stable grid One of the main responsibilities of utilities is to maintain voltage limits to ensure safe , stable and optimised usage . Voltage control is traditionally performed by transformers , using on-load tap changers ( OLTC ) and capacitor banks that inject reactive power into the grid at the MV substation level .
The grid operator then fixes a setpoint and prepares scenarios and ranges based on seasonal load curves , as an example .
However , as we add more distributed energy resources ( DER ) to the grid , effective energy mix management becomes critical . It is paramount – as renewable resources are added – that it is managed intelligently , keeping a close eye on , for example , loads during peak and off-peak times . This will allow for the management of a stable grid comprised of fossil and renewable energy resources .
Supplied Schneider Electric
Vladimir Milovanovic , vice president , Power Systems , Energy Management Business , Schneider Electric .
SF6-free / digital technologies – a powerful force Several new digital solutions can be deployed to address this challenge :
• Next generation RTUs ( remote terminal units ) allow users to remotely control the substation and to accurately track operating parameters to ensure stable operations during loadshedding , for example .
• New smart sensors can be easily installed on new and existing switchgear and can be connected to the cloud , or on-premise systems , as required . This allows for predictive maintenance and EOL management , which are key in reducing long-term costs .
• Digital twin environments allow for virtual modelling of networks , providing insights into equipment performance within the set parameters .
Utilising modern , digital technology , which allows us to untangle the complexity of modern electricity networks and the increasing levels of renewables and DERs coming into the fold , coupled with connected SF6-free switchgear , we are one step closer to finding a sustainable solution to the impact of greenhouse gases on the environment . •
Equipment in sub-stations / distribution centres , is not designed to withstand an onslaught of surges .
www . africanmining . co . za African Mining Publication African Mining African Mining • June 2023 • 33