Control for the Contactless Series Resonant Energy Converter

Control for the Contactless Series Resonant Energy Converter

Stanimir Valtchev (Universidade Nova de Lisboa, Portugal) and Svilen S. Valtchev (University of Lisbon, Portugal & Polytechnic Institute of Leiria, Portugal)
Copyright: © 2019 |Pages: 39
DOI: 10.4018/978-1-5225-5870-5.ch005


This chapter presents control methods applied in the operation of the series loaded series resonant (SLSR) power converters in a most efficient operation zone. The choice of the control method is affected by the objective to guarantee suitably the efficiency, being this method in the same time, relatively easy to apply. The first part of the chapter compares three basic principles of regulation: frequency mode (FM), pulse width mode (PWM), and their combination (PWM/FM). Finally, a new method for instantaneous regulation is developed. The proposed technique consists of a simplified observation of a state variable value to limit each portion of supplied energy, depending on the requirement for power in each half period. The result of this regulation is comparable to the current mode (CM) control applied to the hard-switching power converters. The viability of this new regulation method is demonstrated by simulations of its analogue circuit implementations and experimentally proved. The circuit is also prepared for the changes in the magnetic coupling (contactless energy transfer).
Chapter Preview

2. The Control Of The Slsr And Contactless Converters

Several control methods are known to have been developed during the last 30-35 years and many of them are already considered classical, implemented in factory-made resonant converters, e.g. Hewlett-Packard (1982). The problem of the resonant converter physics is that the energy is flowing from magnetic to electric and vice versa, so the instantaneous control is extremely difficult. It is not possible to cut off the process in the right moment. The difficulty is even greater if contactless energy is to be transferred through a loosely coupled magnetic transmitter/receiver, in which case the reaction should be fastest, to avoid damaging the power switching devices. In the effort to maintain the operation of the SLSR converter stable and efficient and especially, to keep the contactless converter in the best efficiency operation region, the modes of operation were considered, and some graphical methods are already in use, e.g. (Jovanovic, Liu, Oruganti, & Lee, 1987). The safe behaviour of the SLSR converter, especially the transmitting part, is very important for the mass inclusion of the wireless energy in the electric vehicle charging technology (Valtchev, Jorge, Craciunescu, & Brandisky, 2012) and some initial ideas are discussed in (Medeiros, Valtchev, & Valtchev, 2012).

Complete Chapter List

Search this Book: