Increasing Reliability and Efficiency in Next Generation Power Converter Designs (Part 1)


Keysight Technologies
[Application Note]

Introduction

The need to reduce energy consumption as well as CO2 emissions is driving the growth of power electronics and power converters. These needs are driven by growth in the vehicle electrification and home energy management systems where renewable energy usage is becoming more prevalent. Two of the main power converter design drivers are increased conversion efficiency and better reliability. In green energy applications such as solar power, Levelized Cost of Energy (LCOE) is the main decider for what solar inverter a customer chooses for their solar installation. Both efficiency and reliability are two of the main variables in the LCOE algorithm that determines whether your inverter company gets the sale or not. In hybrid electric (HEV) and electric vehicles (EV) reliability is tied to an automotive manufacturer’s reputation and is also linked to safety and the preservation of human life. Hence comprehensive EV test for the various vehicle electrical subsystems at the design and test stages is vital.

The ceiling or limits of these design drivers was getting close for many power converter applications that used power devices based on silicon. The emergence of wide band gap (WBG) power devices based on silicon carbide (SiC) and gallium nitride (GaN) hold promises of raising the ceiling of these design drivers. With the ability to switch faster, handle higher voltages, and larger temperature ranges WBG devices can increase efficiency and reliability as well as reduce form factor in next generation power converter designs. But before power converter designs based on WBG power devices can become main stream there are design and test challenges that must be understood and overcome to utilize them to their full potential.

This is part one in a four part series that takes a look at each stage of the power converter design cycle. At each stage we will look at design and test challenges of next generation power converters and discuss hardware and software tools to help you overcome them. We will put an emphasis on improving the design drivers previously mentioned: increasing efficiency, improving reliability, and reducing form factor. We also consider the design and test challenges that WBG devices introduce into the power converter design cycle. Each of the four parts of this series will cover one of the following design cycles:

1. Power device and component evaluation
2. Design software simulation
3. Hardware design and debugging
4. Design validation and certification

Power Device and Component Evaluation

In this stage of the design cycle engineers want to evaluate the latest power devices (MOSFETs and IGBTs) to use in the next generation of their power converter designs to ensure they can deliver a competitive design that can win in the market. With the emergence of wide band gap (WBG) devices like Silicon Carbide (SiC) and Gallium Nitride (GaN) the task of power device evaluation has become much more challenging. WBG devices offer capabilities such as faster switching via faster slew rates, higher voltage handling capability, and increased temperature range compared to silicon. These capabilities…

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