Model-Based Optimization of an LLC-Resonant DC-DC Converter

Abstract

The study presented in the paper is to guarantee the performance of the LLC DC-DC converter using model-based optimization. The primary scope of the study is to maintain the output parameters regardless of the variation of the values of the circuit elements. In engineering practice, it is known that any schematic element cannot be reproduced with an absolute accuracy of features. In addition, its main parameters change during operation due to changes in operating temperature, aging, operating modes and so on. Optimization procedures are a tool for finding the most appropriate values for circuit elements, with selected constraints, target functions and operating modes. In electronic converters, these are most often: minimal loss, maximum efficiency, the critical-aperiodic transition process, realization of certain dynamics, appropriate modes of operation and so on. The results obtained show that using the proposed approach produces more robustness to disturbances and tolerances, with improved dynamics and faster transient processes. On the other hand, the value of the circuit elements is smaller, and reliable operation of the protection and automatic regulation systems is achieved.

Design Consideration of ZVS Single-Ended Parallel Resonant DC-DC Converter, Based on Application of Optimization Techniques

“…The proposed approach is based on achieving optimal qualities of the power circuits, thereby improving their other indicators. In studies presented in [37], it was proven that model-based optimization, by achieving certain dynamics of the device, improves in addition to its behavior during the transient process and the dependence of the operating mode on the tolerances of the resonant elements.…”

“…Usually, very good results of applying optimization procedures to determine the values of the elements of the power circuits are obtained by setting a reference curve of the output voltage [37,44]. In this way, a certain dynamic of the device is set, which must be achieved as a result of the design.…”

“…Most often, these problems are solved by using an assessment of the residual resource of building elements depending on the conditions of their operation [35] or by statistical methods and probabilistic analysis [36]. A natural development of these methods is the tolerance analysis of power electronic devices combined with model-based optimization [37].…”

Quasi-Boundary Method for Design Consideration of Resonant DC-DC Converters

“…The development and improvement of this method involves the combination of mathematical modeling tools, basic relationships for determining the initial values of circuit elements, based on the analysis of established processes in the circuit, and application of artificial intelligence techniques for the final finding of optimal values of building elements and for control synthesis. This is shown in [29] by using model-based optimization, which realizes, by creating and verifying a model of the converter, a reference (set) trajectory of the parameter to be optimized and the search for a minimum deviation of the parameter from the set optimal trajectory by the method of the smallest squares. Thus, the combination of classical methods for analysis and design and modern means of computational mathematics and modeling eliminates one of the biggest weaknesses in the analysis and design of power electronic devices: the derivation of basic dependencies to be performed with a fixed mode of operation, without taking into account the duration and nature of the transitional processes.…”

A Novel Hybrid Compensation Method Reducing the Effects of Distorted Input Voltages in Matrix Converters

“…2), which provides immunity against input voltage disturbances. This novel method has a hybrid structure, which includes both the feedforward method and the FLC based feedback method [22]. While duty cycles for switches are instantaneously calculated, it takes into account both distortions of input voltages and that of output currents.…”