In a rapidly evolving stage in the development of energy, ‘High-Voltage Direct Current’ (HVDC) is becoming an increasingly popular means of transmitting electrical power. The predominant transmission system is currently ‘Alternating Current’ (AC), which has been successfully utilised both in short- and long-range systems for over a century. Why is it, then, that an entirely different system should be gaining such widespread attention? And what relevance does ABB have in this scenario?
Since the birth of domesticable electrical usage, there has always been a debate concerning the benefits of AC and DC. DC always had a remarkably high potential due to its negligible electromagnetic field, meaning it can be transmitted underground with relatively thin cables and minimal induction losses. But in reality this was outweighed by its impractical heat inefficiencies and incompatibility with step-up and step-down transformers that are essential to grid systems.
Over a hundred years later, radical developments in technology have meant that the potential of DC has finally been harnessed. Solid-state power conversions at the ends of transmission lines have made its compatibility with the national grid viable, and solid (as opposed to oil-filled) dielectrics have significantly reduced heat losses. The high wastage associated with induction, and charging and discharging high current capacitors, are eliminated with HVDC, resulting in a transmission power capacity of approximately 140% of that of AC.
The advantages of HVDC can be seen on performance grounds alone, yet its benefits really come to fruition when we consider green energy. As the world is becoming increasingly aware of a global climate crisis, environmental policy is being placed higher on the agenda corporately and civically. HVDC is better equipped to tackle these issues since it can transfer energy underground, which AC simply cannot technologically achieve. This grants it controllable and reliable access to remote renewable sources such as hydroelectric, wind, geothermal and solar, that would otherwise be impossible.
It is no wonder, then, that there are HVDC initiatives taking place all across the world, the largest of these in China, the USA, and Europe. And the sheer fact that HVDC has been globally adopted, despite the vast costs associated with replacing significant proportions of infrastructure, is testament to the overwhelming evidence in its support.
ABB is leading the way in this global enterprise, setting world records in voltage, longest distance, and largest power capacity of electrical transmission in its new ‘Ultra-High-Voltage Direct Current’ (UHVDC) project spanning the entirety of south-eastern China. The project’s success is demonstrated by the continual plans for expansion; China wish to expand its line to over 5000km, an eighth of the length of the entire equator, and implement the first HVDC grid system before 2022. Yet, there may be something slightly more insidious underlying their success.
ABB has access to the only HVDC circuit breaker available, which led to the proliferation of their investors. Their success ‘snowballed’ as a result, leaving other companies unable to compete, and the power to extortionately overprice their services. From all the relevant switchgears, to surge arrestors and instrument transformers, ABB brands themselves as supplying a comprehensive range of equipment required to ensure that HVDC is sufficiently applicable, which deepens their monopoly further. ABB is now being entrusted with projects in Japan, South Korea, Germany, Pakistan and the UK to name a few, as a symptom of its worldwide repute.
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