Diseño de convertidor Buck-Boost bidireccional tipo puente y analisis de estabilidad utilizando saltos markovianos.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Este documento describe el análisis, diseño, modelación y estrategia de control de un convertidor Buck Boost de 4 switches o Four Switch Buck-Boost Converter (FSBBC) para utilizarlo en una planta fotovoltaica hibrida que puede operar en on-grid y off-grid con la capacidad de inyectar a la red pública excedentes de energía. El FSBBC tiene la capacidad de operar en tres modos distintos: Buck, Boost y Buck-Boost y la operación en estos modos puede provocar corrientes discontinuas tanto en la entrada como en la salida. La topología se adopta por su operación multimodo, que permite cubrir un rango amplio de voltajes de entrada y salida sin cambios en la configuración del circuito. Este comportamiento se considera explícitamente el diseño de la estrategia de control.
El sistema permite cargar/descargar bancos de baterías de diferentes voltajes y además para alimentar un bus DC de voltaje constante. Para la planta fotovoltaica se diseñan controladores basado en el algoritmo del seguidor de punto de potencia máxima (MPPT), para la carga y descarga de baterías se propone un sistema de gestión de baterías (BMS) y finalmente se considera un sistema regulador de voltaje para mantener constante el voltaje del bus DC. Para la gestión general del flujo de energía del sistema entre la planta fotovoltaica, el banco de baterías y el bus DC, se propone un sistema de gestión de energía (EMS) que toma como prioridad la potencia solicitada por la carga eléctrica conectada al bus DC.
Para analizar qué tan estable es el sistema ante variaciones en sus modos se realiza el estudio de estabilidad mediante modelo matricial basado en un sistema de saltos markovianos, considerando posibles variaciones a partir de saltos de Markov.
Se proponen controladores para la regulación de corrientes de carga y descarga de baterías por medio de controladores PI de voltaje y corriente en cascada. Estos controladores son diseñados utilizando el programa de simulación Matlab y los distintos modos de operación del modelo del convertidor son simulados en Simulink mediante un modelo de circuito equivalente.
Los resultados demuestran que los modelos propuestos para modelar los estados de operación funcionan adecuadamente para el proceso de carga y descarga de batería ante distintas condiciones de la planta fotovoltaica. Finalmente, el análisis de estabilidad utilizando los saltos markovianos demuestran que, ante cambios de operación de forma aleatoria, el sistema es estable a pesar de las variaciones del sistema.
This document describes the analysis, design, modeling, and control strategy of a four-switch buck-boost converter (FSBBC) for use in a hybrid photovoltaic plant that can operate on-grid and off-grid with the ability to feed surplus energy into the public grid. The FSBBC could operate in three different modes: Buck, Boost, and Buck-Boost, and operation in these modes can cause discontinuous currents at both the input and output. The topology is adopted for multimode operation, which allows a wide range of input and output voltages to be covered without changes in the circuit configuration. This behavior is explicitly considered in the design of the control strategy. The system allows charging/discharging battery banks of different voltages and also powers a constant voltage DC bus. Controllers based on the maximum power point tracking (MPPT) algorithm are designed for the photovoltaic plant. A battery management system (BMS) is proposed for charging and discharging batteries, and finally, a voltage regulator system is considered to maintain a constant DC bus voltage. For the overall management of the system's energy flow between the photovoltaic plant, the battery bank, and the DC bus, an energy management system (EMS) is proposed that prioritizes the power requested by the electrical load connected to the DC bus. To analyze how stable the system is in the face of variations in its modes, a stability study is carried out using a matrix model based on a Markov jump system, considering possible variations based on Markov jumps. Controllers are proposed for regulating battery charging and discharging currents using cascaded voltage and current PI controllers. These controllers are designed using the Matlab simulation program, and the different operating modes of the converter model are simulated in Simulink using an equivalent circuit model. The results show that the proposed models for modeling operating states work adequately for the battery charging and discharging process under different conditions at the photovoltaic plant. Finally, the stability analysis using Markov jumps shows that, in the event of random changes in operation, the system is stable despite variations in the system.
This document describes the analysis, design, modeling, and control strategy of a four-switch buck-boost converter (FSBBC) for use in a hybrid photovoltaic plant that can operate on-grid and off-grid with the ability to feed surplus energy into the public grid. The FSBBC could operate in three different modes: Buck, Boost, and Buck-Boost, and operation in these modes can cause discontinuous currents at both the input and output. The topology is adopted for multimode operation, which allows a wide range of input and output voltages to be covered without changes in the circuit configuration. This behavior is explicitly considered in the design of the control strategy. The system allows charging/discharging battery banks of different voltages and also powers a constant voltage DC bus. Controllers based on the maximum power point tracking (MPPT) algorithm are designed for the photovoltaic plant. A battery management system (BMS) is proposed for charging and discharging batteries, and finally, a voltage regulator system is considered to maintain a constant DC bus voltage. For the overall management of the system's energy flow between the photovoltaic plant, the battery bank, and the DC bus, an energy management system (EMS) is proposed that prioritizes the power requested by the electrical load connected to the DC bus. To analyze how stable the system is in the face of variations in its modes, a stability study is carried out using a matrix model based on a Markov jump system, considering possible variations based on Markov jumps. Controllers are proposed for regulating battery charging and discharging currents using cascaded voltage and current PI controllers. These controllers are designed using the Matlab simulation program, and the different operating modes of the converter model are simulated in Simulink using an equivalent circuit model. The results show that the proposed models for modeling operating states work adequately for the battery charging and discharging process under different conditions at the photovoltaic plant. Finally, the stability analysis using Markov jumps shows that, in the event of random changes in operation, the system is stable despite variations in the system.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Electrónico/a.
Keywords
Modelos estocásticos, Circuitos electrónicos, Convertidores eléctricos