Specialised Power Converters

New applications, lower losses and robust control.

There are frustrating challenges around developing power converters and modules to support advanced power electronics control. New applications need new converters and power engineers are in short supply. And as with all technology power converters are getting more complex. Digital control increases performance. Power electronics businesses with a modular converter definitely need power converters as this is the foundation of the business. Often off the shelf converters do not suit the application perfectly. Space constraints and performance constraints often require custom solutions.

 Specialised power converters are really difficult to find. High voltage power converters are even more difficult to find. For all your power converter design needs, get in touch with the experts at ELMG Digital Power today.

Specialised Parallel connection

Modular converter design leverages purchasing volumes to decrease the total converter cost and increase the flexibility.  Parallel connection of power converters to increase the power rating is achieved by designing the sharing system.  Managing the converter interaction when the load changes and the converters transition into and out of current limit is achieved with slope droop and by matching the gain of the current limit loop to the voltage loop.  Converter control bandwidth, output impedance, current limit small signal gain and the effects of the digital control precision all need to be taken care of.

Hybrid vehicles have interconnected power converters. The operation of the traction motor drive power converter can interact with the DC to DC converter for the auxiliary twelve volts. Coordinating the switching, EMC filters and the transient stability can be difficult when the converters are from different Tier 1 and Tier 2 vendors.

Converter interaction with other converters

Multiple AC converters connected to the same electrical bus interact with each other and the AC grid.  Often there are widely diverse switching frequencies from 100Hz (120Hz for 60Hz) for a single phase rectifier to 30kHz for a solar inverter.  Dealing with these interactions requires tools to show the interaction of the converter and control behaviour.  Measuring these interactions using injected disturbances provides very useful information.  Using ELMG self-measurement on the converters allows the converter interaction to be managed.

ELMG high voltage technology enables entry to high voltage markets.

High voltage converters 2.3kV to 500kV

High voltage converters allow very large power.  The large electric fields at high voltage can cause partial discharge and corona with the associated insulator destruction and converter failure.  Managing the high dv/dt and common mode currents is challenging.  Gate drives and instrumentation need to have very balanced electronic design so the common mode does not get converted into differential mode which can cause false gate signals or create false measurements.

ELMG high voltage technology enables entry to high voltage markets.

Confirmation of the temperature rise of the converter components using actual measurements is always necessary and ensures that the power converter will be robust and reliable.

How to do Thermal management

Power losses in power electronics created heat.  Managing that heat to ensure low temperature operation ensures long lifetimes and reliable operation.  Increasing the temperature of the converter by ten degrees typically halves the lifetime of the converter. This lifetime acceleration means accurate thermal management of the converter is essential.  To ensure long lifetime and rugged operation of the power converter do the following.

• Calculate the power losses in the converter components using switching and conduction losses.
• Determine the temperature rise for the power loss using the thermal resistances.
• Confirm the thermal performance at the first opportunity in the project by measurement with a thermocouple temperature recorder.

Specialised power converters

Power conversion is a growing market and widely segmented market.  Capturing market share requires specialised power converters.  ELMG provides specialised converter development for specialised applications.

Solution

At ELMG are experienced Senior Power Electronics Engineers with support staff and gear.  Experience in

In ELMG you have a partner who knows and understands power electronics.

Purpose

We aim to design the best digitally controlled power converters and by doing that change the world.  We have been working on digital power for almost twenty five years.  Our approach is to take every care we possibly can to create safe and reliable power converters.  We invest in our people.  We invest in the best tools we can.

Why Christchurch?

Christchurch New Zealand is a hotbed of power electronics.  The HVDC link between the South Island and the North Island drove the power electronics research at the University of Canterbury led by Professor Jos. Arillaga.  ELMG founder Dr. Hamish Laird is an Adjunct Research Fellow at the Electrical and Computer Engineering Dept at the University of Canterbury.  The good power school has led to a number of power electronics companies setup in Christchurch.  And then there is ELMG.  We are working on changing the world one power converter at a time.