DC-DC High-Voltage-Gain Converters with Low Count of Switches and Common Ground

Abstract

This paper presents a new concept and research results of DC-DC high-voltage-gain, high-frequency step-up resonant converters. The proposed topologies are optimized towards minimizing the number of switches and improvements in efficiency. Another relevant advantage of such type of converters is that they have a common input and output negative point. The proposed converters are based on the resonant switched-capacitor voltage multiplier circuit, and that is why they are compared with a classic converter from this family. The included results show the operating principle, possible switching methods with the consideration of their impact on the voltage gain level, as well as the voltage and current ripples. The operating concepts and analytical calculations are confirmed by simulation and experimental results.

Input Current Ripple Reduction in a Step-Up DC–DC Switched-Capacitor Switched-Inductor Converter

“…1 in [34]. The converter is composed of a specific switched-capacitor voltage multiplier (SCVM) [3] and a switch-mode boost converter that directs its inductor current to an internal capacitor of the SCVM. The input current of the SCVM converter is composed of pulses, as in the classic converter presented in [33].…”

“…The input current ripple is associated with the method of operation of the SC circuits that is based on the charging and discharging of the switched capacitors in various configurations. This is clearly seen in SC voltage multipliers [2]- [4], such as a classic multiplier discussed in [2], or the converter presented in [3], where the input current can be approximated by a rectified sinusoidal shape. In other types of SC series-parallel converters, like those presented in [4], the input current is even deteriorated by zero-current periods that occur between the sequences of pulses, or an inequality of pulses occurs [5].…”

“…It operates in the boost topology and converts the energy from the input capacitor to an internal capacitor in the SC converter where the voltage is equal to half of the output voltage. This is possible thanks to the application of the innovative SC topology [3], which finally allows to design an SI converter for low voltage stresses of their devices. The SI part used in the proposed hybrid converter requires a very low choke inductance, as the boost converter operates in the DCM mode with a voltage gain of less than two.…”

DC-DC High Voltage Gain Switched Capacitor Converter With Multilevel Output Voltage and Zero-Voltage Switching

“…The majority of SC converters operates with a fixed voltage gain, especially in applications where a relatively high conversion ratio is needed [5], [24]- [27]. Yet, in some topologies the voltage gain can be changed to achieve various levels of output voltage [27]- [34].…”

“…In its basic configuration, this device uses 7 switches and allows for a seven-time increase in the gain of the voltage. Reference [24] presents the device where a four-fold voltage amplification is achieved with the use of just three transistors. LC based switched capacitor converter in [13] obtains an extremely high conversion ratio, which is an important merit.…”