A novel control concept for high-efficiency power conversion with the bidirectional non-inverting buck-boost converter

Abstract

This paper presents a novel control concept for the bidirectional non-inverting buck-boost converter to achieve extreme high-efficiency power conversion. The duty cycle, duty ratios and time delays of the PWM control signals for the switches are modulated depending on operating points to minimize the power losses in the converter. A 3kW prototype of the converter using SiC MOSFETs has been designed and tested for the verification of the control concept. Measurement results show that the prototype achieves power efficiency between 97.79% and 99.60% over a power range 'input voltage from 300V to 500V, output voltage from 200V to 600V and output current from 1A to 5A'

State-of-the-Art Review on Soft-Switching Technologies for Non-Isolated DC-DC Converters

“…The non-inverting Buck-Boost converter can be regarded as a cascaded DC-DC converter of a Buck converter and a Boost converter without the low-side filter capacitor. Based on the switching characteristics of the non-inverting Buck-Boost converter, 6 modulation strategies are proposed [7]. And the waveform of a soft-switching modulation strategy is shown in FIGURE 3.…”

“…For the NIBBC, above-mentioned soft-switching methods can be used to be control-only soft-switching NIBBCs [143][144], ALC ZVS NIBBCs [145][146][147], and ZVT NIBBCs [148][149] [150]. The NIBBC has several softswitching modulation methods listed by [144]. Based on these methods, S. Waffler and J. W. Kolar proposed a lowloss modulation strategy for high-power NIBBC with a peak efficiency of 98.3% [143].…”

A Soft-Switching Control for Cascaded Buck-Boost Converters Without Zero-Crossing Detection

“…The negative current is calculated and its value is about one third of the average current, while this relatively large negative current will influence the power transmission and system efficiency. A novel control concept for CBBC is presented in [37], while the PWM control signals are modulated depending on operating points to minimize the power losses. The optimal duty ratios are chosen in modulation, but a lot of restrictions in the selection process are needed.…”

“…One of the advantages of the zero-crossing detection is that −I 0 can be controlled to increase the efficiency. By comparison, the method of timer and time calculation in [33], [36], and [37] would produce great error of −I 0 , which will reduce the efficiency. To avoid the zero-crossing detection and improve efficiency, −I 0 is precisely controlled by calculation and an inductor current is measured to heighten the control accuracy.…”

Open H‐Bridge Topology‐Based Edge‐Resonant Zero Current Soft‐Switching PWM‐Controlled Bidirectional DC‐DC Converter

“…Additionally, there are soft switching BDCs in which snubber capacitors are added to the four switches depicted in Fig. , and in which the parasitic capacitance of a power MOSFET is used . Such configurations use a relatively simple circuit structure and enable the soft commutation of all of the switches in both forward and reverse operation, but the operating principle thereof is based on the phase difference control of the two half bridge (HB) inverters with an inductor disposed there between.…”