The megatrends of urbanisation and the focus on energy savings and efficiency are well aligned with the use of AC drives. And, in particular, the use of medium voltage (MV) drives. There are several reasons why I think that MV will play a key role in the future of AC drives.
Essentially higher power with increased voltage creates lower current, fewer losses and reduced system costs (related to transformers and cables). Industries such as water (water treatment and water pumping stations), power generation, marine, mining and metals, to name a few, are taking advantage of the benefits of reduced costs and losses that medium-voltage drives have to offer.
So, what is the right approach to select between LV and MV? There is not really one fixed power spot where it makes sense to go MV. But, for sure, we are talking about a range of several hundred kWs (300–500 kW) in practice. Roughly speaking, the bigger the power the better the gain due to the current reduction.
Medium-voltage drives also work on economies of scale. Motors are getting bigger in many industries and in a wide range of use cases, and a single MV drive can run multi-megawatt motors. And, because the MV drive operates when matched, and this is of course the goal, with grid voltage, there are no requirements for input transformers. This leads to a reduction in overall system costs.
Medium-voltage drives come in multi-pulse or Active Front End models to meet network requirements also in terms of harmonics content. And, although highly powerful, not all MV drives today are physically large in size. They are therefore more attractive and suitable for various installations, industries or use cases, while, at the same time, enhancing system performance, efficiency and safety.
The global megatrends support the accelerated growth of the medium-voltage drives market, and I am excited that Vacon is aiming to be a part of this growing market in the future.
Article by: Jari Marjo – Marketing Director, Premium Drives, Vacon Ltd
