Optimized Power Converters for MV Drive

“Optimize your Power Converters: With Faster, Lighter, Cheaper and More Efficient Designs.
Get to the Next Level of Power Converters!”
Find out more with this example on Medium Voltage drive…

Thanks to its fast, robust and intuitive software design solution, The Tom Thumb of power electronics: Power Design Technologies knows no bounds when it comes to new applications and markets. Its proprietary software: PowerForge offers the most powerful power converter design tool available to optimize trade-offs in various fields (naval, wind, photovoltaic, manufacturing, shipping, electric cars, aeronautic, storage systems…) and as you will see in this article in Medium Voltage Drive applications.

By Guillaume Fontes, Nicolas Videau, Aurélie Cretté & all the other members of the Power Design Technologies Team

mv drive power design technologies

Don’t you live in the kingdom of power electronics and its autocratic regime?

Power Converters are ubiquitous in all industrial power electronics fields. Obviously not every application will have the same set of challenges, yet power converter design has become a key expertise, no matter what the end-industry is. And no matter what your end-industry is, you are surely facing the four sacred dimensions of trade-off when you design power converters: mass, volume, loss, cost; and the absolute rule of specs: reduce at least one of them! Don’t you?

The Tom Thumb of Power Electronics found a solution to change the rules!

Building on a small and agile team of 7 high profile power electronics experts that cumulate more than a 100-year experience, Power Design Technologies is an electrical engineering software publisher specialized in power electronics that was founded in 2016. The following year, it completed a €600,000 seed funding round with technology investors. Since then, after signing an international distribution agreement with Powersys, it has been gradually establishing its position as a dynamic innovator with an imaginative integrated software solution for the design of high-performance electric power converters, enabling lighter and smaller product development while ensuring greater affordability, efficiency and reliability. 

Find your way around the constraints of designing power converters in all applications!

Power Design Technologies’ cutting-edge power electronics approach and decades of research and process expertise come together in Power Design Technologies design software solution: PowerForge suitable for a wide range of industrial applications whenever energy converters need to be more compact, more efficient, more reliable and more affordable. PowerForge is the very first computer-aided engineering solution dedicated to the design of power converters for energy-transition-related applications: solar PV inverters and associated storage systems, electric vehicle fast chargers and motor drive inverters….

An Example: Starting with Medium Voltage Variable Speed Drive Design…

Power conversion systems demand efficient and reliable drives. Variable speed drives are used in a wide range of applications in industry such as in wind turbines, mining, marine… and transports. Demand for these drives has been growing for a few years, especially at the megawatt level (i.e. at the medium voltage level), due to the increasing need for efficient motor control because of rising energy prices and environmental concerns.

In this context, a major use case is the retrofit of an existing Medium Voltage motor originally powered straight from the grid. In this case, the introduction of a variable speed drive is very interesting because:

1- it saves a motor replacement: current inrush peaks are eliminated. The motor speed gradually goes up by increasing output voltage hence avoiding peak demand charges.

2- it increases the operating efficiency: Medium Voltage drives enable greatly improved control accuracy and efficiency in your process compared to Low Voltage drives.

3- it increases safety: In response to load, Medium Voltage drives provide appropriate power usage based on actual demand and consumes only the energy to drive the attached equipment hence providing the required energy savings.

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Figure 1: Influence of the increase of the number of levels on the current THD and the voltage overshoots

But you know that as it used to be a motor powered straight from the grid, you need to be very careful about the stress of the motor windings in MV drives. When you are exploring design solutions for MV drives, many questions are raised:

– Which topology fits better to my application?

– Depending on the number of voltage levels, which power-switch?

– What about the switching frequency?

In most of cases, the use of 3-level inverters (such as NPC or T-type topologies) is already a well-established solution. But what about going to the next level(s)?

 

…What about taking MV drives to the next level?

To preserve the motor’s windings from excessive current harmonics and voltage overshoots, this often requires a bulky and costly output sine filter. However, further increasing the number of levels (to 5 for example) can change the game, first by reducing the current harmonics, which leads to significant filter downsizing.

Besides, fast voltage transitions caused by the PWM waveform may cause voltage spikes that degrade the insulation of the motor winding. Sometimes, voltage transitions are slowed down by increasing the gate resistance of the switches, but the overall efficiency is affected. Here again, multilevel solutions reduce the voltage step, thus reducing the spike amplitude.

At last, it also opens options such as the use of cheaper low-voltage IGBT modules.

 

Power Forge could help you find your way to the next level of MV drives!

Our design software: Power Forge allows MV drives design trade-off from 100kW to more than 100MW and from 3.3 up to 13.8kV voltages while ensuring high efficiency, better affordability and smaller and lighter product development.

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Figure 2: Comparison charts for different topologies in PowerForge (efficiency vs specific power, mass and cost breakdown)

 

A final taste of our bread crumbs?

Take the path to the next level of Power Converter design with PowerForge! Do you share our ambition to bring energy conversion to the next level? Now is the time to join us and start exploring the next level power converter design!

PowerForge is a powerful platform for designing, exploring and comparing power converter designs allowing optimized technico-economic trade-offs at an early stage. Thanks to multidisciplinary integration, PowerForge will bring you a unique tool for designing lighter, smaller and more efficient converters in record time.

Centered -around optimizing your workflow, PowerForge offers a seamless experience from product specification stages to trade-off of most complex topologies including multilevel (3 to 5) and sizing of passive and active components.

With Power Forge, be ready to:

  • Design cutting-edge conversion
  • Reduce time-to-market
  • Streamline your design workflow

Check our homepage (www.powerdesign.tech) or browse our page on Medium Voltage Drive applications for more details!

First published Bodo’s Power Systems®  – May 2019 ; ISSN: 1863-5598 – Gießen, Germany