Hitachi Energy: How Power Electronics Enables Zero-Energy System

Q: HOW HAS POWER ELECTRONICS CHANGED OVER THE PAST FEW DECADES? WHAT ARE THE MOST NOTABLE IMPROVEMENTS?

Professor Frede Blaabjerg (F.B), Aalborg University: The biggest change is that this technology is being applied across so many facets of society. Back in the day, we always thought this could be a possibility, but we did not imagine it would go this fast. This applies to power generation, transmission and distribution, as well as electricity consumption. When I entered the field many years ago, the main application for power electronics was in the industrial space, for example on how to use it to optimize energy efficiency – and that was the start of drives applications.

Since then, we’ve seen a huge amount of different applications where this technology is making a big difference. Let me just highlight a few: think of the huge data centers supporting our digital world and the vast amounts of energy they consume to run their operations; or electrification of the transport sector where electric vehicles need to be equipped with batteries. These examples require equipment with power electronics.

Q: WHY IS POWER ELECTRONICS THE ENABLER OF RENEWABLE ENERGY?

F.B: When dealing with electrical energy, it is important to be able to control it well. For example, we need power conversion when optimizing power generation from wind turbines and solar photovoltaic plants as wind and sunshine change the plants’ output characteristics throughout the day. This controllability is enabled by power electronics. We would not be able to integrate renewable energy to the extent we are doing today without using this technology. One major factor is how quickly it reduced its cost, which has been driven by volume growth, but also technological innovation on both the component (semiconductor devices) and system (power converter) sides. Thanks to consistent improvement in technology and in reliability, power electronics is being implemented at a large scale and is really enabling renewable energy growth.

Ines Romero (I.R), Hitachi Energy: What is worth mentioning here is how power electronics transformed the entire wind industry. The first wind turbines had a very basic soft starter solution based on thyristor technology. As the industry evolved and turbines needed to better control power output and offer system services, they relied on power electronics to provide additional functionalities. This has equipped turbines with full power processing, allowing the wind industry to turn into a reliable energy resource. It’s enabled them to support the grid with reactive power and, more recently, with frequency and inertia to allow seamless integration in the power system, supporting grid planning and operations.