Wireless Input-Voltage-Sharing Control Strategy for Input-Series Output-Parallel (ISOP) System Based on Positive Output-Voltage Gradient Method

Abstract

An input-series output-parallel (ISOP) system, in which multiple converter modules are connected in series at the input sides and parallel at the output side, is very suitable for high input-voltage, low output-voltage, and high output-current applications. Input-voltage sharing (IVS) and output-current sharing of the constituent modules among the ISOP system must be ensured. The existing IVS control strategies have drawbacks of lower reliability and lower modularity. In this paper, we propose a wireless IVS control strategy for ISOP systems based on positive output-voltage gradient method, which can effectively improve the reliability and modularity of ISOP systems. First, the operation principle of the proposed control strategy is introduced, and the IVS performance and output-voltage regulation characteristics of ISOP systems are analyzed. The stability of the proposed control strategy is also explored. A three-module ISOP system prototype is fabricated and tested in the laboratory, and the experimental results verify the effectiveness of the proposed control strategy.Index Terms-Input-series output-parallel (ISOP), inputvoltage sharing (IVS), positive output-voltage gradient method, stability, wireless.

Highly Efficient dc–dc Transformer Based on Multicell Converter Topology for Next Generation dc Distribution System

“…There have been many reports on analysis of the converters in ISOP connection [7][8][9][10]. On the other hand, when nonregulated dc-dc converters, which do not perform voltage constant control, are connected by ISOP, it is possible to avoid a voltage concentration in the steady state as stated in (3).…”

“…If the voltage unbalance is large, overvoltage may stop control of the cell converters or even break them. There have been many reports on analysis of the converters in ISOP connection [7][8][9][10]. While methods to compensate the input voltage unbalance by some controlling process have been proposed, no instances of nonregulated dc-dc converters are included there.…”

Novel bifunctional converter‐based supercapacitor energy storage module with active voltage equalizing technology

“…To form an SC module, the input ends and the output ends of each module are connected in series. Thus the module is based on an input-series-output-series (ISOS) converter [29][30][31]. The schematic diagram of a three-cell SC module is shown in Fig.…”

Decentralized Inverse-Droop Control for Input-Series–Output-Parallel DC–DC Converters

“…However, excellent power sharing can only be achieved for modules with identical parameters. The exact sharing of the power can be achieved with the control in [3]- [10]. The relationship of IVS and OCS are revealed in [3], indicating that IVS can be achieved when OCS is obtained and vice versa.…”

“…A decentralized control [10] without communication among individual modules is used to achieve the power sharing. However, the output voltage of the converter is affected by its input voltage, and the output regulation characteristic suffers from individual input voltages especially when the total input voltage range is wide.…”