Capacitive Matrix converters

Abstract

This paper describes three ideal topologies of switched-capacitor converters, taking into account integration considerations and multiple DC voltage ratios. First, the ideal continuous capacitor idea is described, and then a Matrix of Capacitors configuration is proposed. This configuration is based on rectangular matrices of capacitors charging and discharging in transposed configuration for achieving the input/output DC voltage ratio. The third topology is The General Transposed Series-Parallel configuration. This is a modification with a discrete number of capacitors. The configuration is based on parallel brunches of series capacitors in the charging state and series elements of parallel capacitors in the discharging state. This topology is suitable for fine tuning in the DC voltage ratios. The Matrix and the Transposed Series-Parallel topologies are compared for an input/output ratio of 1.1. In the later topology, fewer components are required for the assumed ratio. Simulation is performed for 3 elements in the Transposed Series-Parallel topology, where each element consists of two dual identical capacitors for the elimination of external large capacitors.

Modular Realization of Capacitive Converters Based on General Transposed Series–Parallel and Derived Topologies

“…GTSP is another evolution of the SP and matrix converters [24], [25]. This topology is the most versatile topology with a reduced number of capacitors and switches, including a large number of input/output voltage ratios [4], [17]. Further examination of this topology yields the conclusion that this topology is a general case, which includes the SP and matrix topologies as particular cases.…”

“…It has been found that the GTSP topology enables a large number of transfer ratios determined by the sum of all partition functions of the integer numbers equal to or smaller than n, where n is the number of capacitors [4], [17]. For 20 capacitors, over 2000 transfer ratios can be obtained, which implies good fine-tuning capabilities [4].…”

“…In the GTSP topology, an increased number of transfer ratios can be achieved by a modest increase in the number of capacitors n, because the number of transfer ratio options is the sum of all partition functions up to n. This number significantly increases as n increases [17]. Unfortunately, the increase in the number of capacitors implies an exponential increase in the complexity of the synthesis problem, which makes the heuristic construction method unacceptable.…”

“…It has been found that the structure that realizes the GTSP converter yields a large number of conversion ratios that follow the sum of partition functions up to the number of cells. This function is a mathematical function that represents all possible variations of the topology [17].…”

“…This paper presents the basic cell of the modular structure, as well as the connectivity between the cells for forming the functionality of the general transposed series-parallel (GTSP) topology. In the initial stages of GTSP development [4], [17], the research focused on the structure of the topology, the calculation of the possible number of transfer ratios (as a function of the number of capacitors), their values, and the distribution function of those transfer ratios with special attention to the range that implies "fine-tuning" (regulation) capabilities. At that stage, no attention was paid to the synthesis of the SN, which would enable the realization of the topology, as it was assumed that it would be an easy task to find some SN that would work.…”