Modern Control Methods For LLC Converters Simplify Compensator Design

Focus:

Among resonant converter architectures, the LLC converter has gained popularity due to the many LLC controller ICs available. With its nice sinusoidal waveforms, this converter supports soft-switching and EMI-friendly applications. This article reviews the techniques available to control LLC converters, starting with the traditional method--direct frequency control--and provides an overview of recommended controllers from various suppliers. This article focuses on the more up-to-date LLC operating methods such as bang- bang charge control, charge-current-mode, current-mode and time-shift control. By changing the ac response of the LLC converter, these control techniques simplify the required compensator design, while providing other benefits such as faster transient response. Implementations of these control methods are illustrated using several of the newer LLC controller ICs, some of which also implement PFC control.

What you’ll learn:

• How to implement LLC converters using different forms of control and different controller ICs
• How to simplify compensation requirements for an LLC converter from a type 3 to a type 2 compensator

View the Source

Author & Publication:

Christophe Basso, Future Electronics, Toulouse, France, How2Power Today, Dec 15 2021

This article summary appears
in the HOW2POWER Design Guide.

The Design Guide offers
organized access to
hundreds of articles
on dozens of power conversion
and power management topics.

The Design Guide search results
include exclusive summaries
and accurate "how to" analysis
to help you make faster,
more informed decisions.

Search
for more articles