LCC Resonant Multilevel Converter for X-ray Applications

Abstract

Medical X-ray appliances use high-voltage power supplies that must be able to work with very different energy requirements. Two techniques can be distinguished in X-ray medical imaging: fluoroscopy and radioscopy. The former involves low power radiation with a long exposure time, while radioscopy requires large power during short radiographic exposure times. Since the converter has to be designed by taking into account the maximum power specification, it will exhibit a poor efficiency when operating at low power levels. Such a problem can be solved by using a new multilevel LCC topology. This topology is based on a classical series-parallel resonant topology, but includes an additional low-voltage auxiliary transformer whose function depends on the X-ray technique considered. When radioscopy operation is selected, the transformer will allow the power to be shared between two full-bridges. If fluoroscopy mode is activated, the auxiliary full bridge is disconnected and the magnetizing inductance of the auxiliary transformer is used to increase the resonant inductor in order to reduce the resonant currents, thus improving the efficiency of the converter.

Resonant Power Converters for Renewable Energy Applications: A Comprehensive Review

“…Among the highlighted aspects are the design optimization, analysis of operation modes, and performance behavior (Liu et al, 2018;Chen et al, 2020). LCC RPC has been used and experimented in several industrial systems, among them, in battery chargers for PV systems (Rakhi et al, 2014), furnace power supply during electron beam melting (Haifeng and Peng, 2017), x-ray applications (Pernía et al, 2017), and xenon flash lamp simmer circuit (Song et al, 2019).…”

“…It is suitable for fuel-cell power systems (Jin and Ruan, 2006). Besides, it is also widely adopted LCC RPC is suited for high-voltage applications (Abdul-Hakeem et al, 2018) and has been used in battery chargers for PV systems (Rakhi et al, 2014), in furnace power supply during electron beam melting (Haifeng and Peng, 2017), in x-ray applications (Pernía et al, 2017), and for xenon flash lamp simmer circuit (Song et al, 2019) This type of converter is good for use in lowvoltage, high-output current systems, and it can be used in power systems and telecommunication (Bhat, 1994). It is good for applications such as space and radar high-voltage power supplies and it can also be used with a stand-alone wind generator (Bhat, 1997) frequency above the required level for full load operation will main the converter efficiency and confer other desirable features on the converter (Bhat, 1994); there will also be a decrease in the peak current passing through the switches as the load current reduces (Bhat, 1995;Almardy and Bhat, 2011).…”

A Novel Multi-Element Resonant Converter with Self-Driven Synchronous Rectification

“…Therefore, the secondary conduction losses can be significantly reduced. Furthermore, compared with a series resonant converter (SRC), a parallel resonant converter (PRC) and a series-parallel resonant converter (SPRC) [5,6], LLC resonant convertors allow a narrow switching frequency variation during the output load and input voltage variation [7,8]. Therefore, the LLC resonant converter can be simpler to design an electromagnetic interference (EMI) filter [9][10][11].…”

A Digitally Controlled Power Converter for an Electrostatic Precipitator

“…This topology has, however, one drawback in our case: it is not easy to design the inductor in the output filter when the output voltage is very high. Thus, for the sake of simplicity, many high-output DC voltage applications use a PRC-LCC resonant topology with only a capacitor as output filter, as shown in Figure 1 [20][21][22][23]. The price to pay for this simplification in the assembly is a more complicated performance of the topology, since the use of a purely capacitive filter results in discontinuousconduction-mode operation.…”

“…The price to pay for this simplification in the assembly is a more complicated performance of the topology, since the use of a purely capacitive filter results in discontinuousconduction-mode operation. Nevertheless, this is not much of a problem, for the behavior of this topology has already been described and developed by means of different mathematical models for a half-bridge [20,24] where several topologies are compared, for a PRC-LCC topology [21,23,25,26]; for high voltage pulse loads [22] and full bridge Zero Current Switching Pulse Wide Modulation (ZCS PWM) application in [27]. Other models have been developed in [28][29][30][31] for LCC-type parallel resonant converter.…”