Advances in Control of Power Electronic Converters

This book proposes a list of contributions in the field of control of power electronics converters for different topologies: DC-DC, DC-AC and AC-DC. It particularly focuses on the use of different advanced control techniques with the aim of improving the performances, flexibility and efficiency in the context of several operation conditions. Sliding mode control, fuzzy logic based control, dead time compensation and optimal linear control are among the techniques developed in the special issue. Simulation and experimental results are provided by the authors to validate the proposed control strategies

Sliding Mode Control System of Single Phase Buck-Boost Inverter with Buffer Inductor

Inverter is one of the primary components of a distributed electric power plants that serve as modifiers DC voltage into AC. In this research is applied of the Sliding Mode Control on Inverter Buck Boost One phase with Buffer Inductor. In the Open Loop test with the source voltage of 60 Volts, generate graphics output voltage in the form of a sinusoidal wave with maximum amplitude of about 400 volts. In the Closed Loop test, the graph output voltage can be controlled to follow a set point with SMC control method of order 2, and the resulting value Error Steady State smallest at 300 Volt, which amounted to 3.33%. The smallest sensitivity value of 0.29 when the input voltage changes by 32%

Nonlinear control of two-stage single-phase standalone photovoltaic system

This paper presents a single-phase Photovoltaic (PV) inverter with its superior and robust control in a standalone mode. Initially, modeling and layout of the Buck-Boost DC-DC converter by adopting a non-linear Robust Integral Back-stepping controller (RIBSC) is provided. The controller makes use of a reference voltage generated through the regression plane so that the operating point corresponding to the maximum power point (MPP) could be achieved through the converter under changing climatic conditions. The other main purpose of the Buck-Boost converter is to act like a transformer and produce an increased voltage at the inverter input whenever desired. By not using a transformer makes the circuit size more compact and cost-effective. The proposed RIBSC is applied to an H-bridge inverter with an LC filter to produce the sinusoidal wave in the presence of variations in the output to minimize the difference between the output voltage and the reference voltage. Lyapunov stability criterion has been used to verify the stability and finite-time convergence of the overall system. The overall system is simulated in MATLAB/Simulink to test the system performance with different loads, varying climatic conditions and inverter reference voltages. The proposed methodology is compared with a back-stepping controller and Proportional Integral Derivative (PID) controller under rapidly varying climatic conditions. Results demonstrated that the proposed technique yielded a tracking time of 0.01s, a total harmonic distortion of 9.71% and a root means square error of 0.3998 in the case of resistive load thus showing superior control performance compared to the state-of-the-art control techniques

A Three-Phase Boost DC-AC Converter

This paper describes a power conversion circuit conguration for three-phase boost dc-ac converter (inverter) based on the dc-dc boost converters. It naturally generates in a single stage three-phase ac voltages whose peak values are greater than the dc input voltage. This property is absent in the conventional three-phase inverter, as it inherently bucks. The proposed three-phase inverter comprises three dc-dc boost converters whose individual output voltages are modulated sinusoidally. Sliding mode controllers are designed to perform a robust control for the three boost dc-dc converters. Computer simulations and spectral analysis demonstrate the feasibility of the proposed three-phase inverter. The inverter is intended to be used in three-phase electric drives and uninterruptible power supply (UPS) systems

Operation and control design of new Three-Phase inverters with reduced number of switches

DC/AC inverter topologies having reduced numbers of switches to reduce costs, total inverter size and switching losses have previously been proposed. In addition, these topologies reduce the likelihood of semiconductor switch damage, and have lower common-mode currents. This paper proposes new designs for inverters with reduced switch numbers. For three-phase systems, the proposed inverters use four switches instead of the six used in the traditional three-phase Voltage Source Inverter (VSI). Compared to the traditional Four-Switch Three-Phase (FSTP) inverter, the proposed FSTP inverters improve the voltage utilisation factor of the input dc supply, without the need for triplen injection. Sliding-mode control is used to demonstrate the dynamic response and robustness of the inverters. Also the paper presents new single-phase inverters with two switches instead of the four used in the traditional VSI. The capability of suppressing the 2nd order current harmonic from the input dc side is discussed. The basic structures of the proposed inverters and their operation, switch ratings, controller design with supporting mathematical equations, and MATLAB/SIMULINK results are presented. Practical results, based on laboratory prototype circuitry controlled using a Texas Instruments TMSF280335 DSP, are presented to demonstrate the design flexibility and operation of the proposed topologies

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

Fixed-switching frequency sliding mode control applied to power converters

The application of the sliding mode control in power converters has a well-known inconvenient from the practical point of view, which is to obtain fixed switching frequency implementations. This thesis deals with the development of a hysteresis band controller in charge of fixing the switching frequency of a sliding motion in power electronics applications. The proposed control measures the switching period of the control signal and modifies the hysteresis band of the comparator in order to regulate the switching frequency of the sliding motion. The proposed structure becomes in an additional control loop aside from main control loop implementing the sliding mode controller. In the first part of the thesis, the switching frequency control system is modelled and a design criteria for the control parameters are derived for guaranteeing closed loop stability, under different approaches and taking into account the most expectable working scenarios. In the second part of the thesis, the proposed strategies are applied to several power converters prototypes. Specifically, DC-to-DC and DC-to-AC power converters are built and the experimental results are shown. In this part, the strategies used for implementing the controllers are also deeply discussed.La aplicación del control en modo deslizante en el ámbito de la electrónica de potencia presente una problemática ampliamente conocida, obtener aplicaciones a frecuencia fija de operación. Es esta tesis se estudia el desarrollo de un comparador con histéresis variable encargado de regular el periodo de conmutación de controladores bajo regímenes deslizantes en convertidores de potencia. La estructura propuesta mide el periodo de conmutación de la señal de control y actualiza, de manera adecuada, la banda de histéresis del comparador a tal fin de regular la frecuencia de conmutación al valor deseado. La solución propuesta forma un segundo lazo de control, además del lazo de control principal que implementa el controlador en modo deslizante. En la primera parte de la tesis, éste segundo lazo es modelado, haciendo posible el estudio de las condiciones de estabilidad bajo realizaciones en tiempo continuo y en tiempo discreto. Además, se estudian las condiciones típicas de trabajo de los controladores utilizados en convertidores de potencia, como son los esquemas de regulación y de seguimiento de señales variantes en el tiempo. La segunda parte de la tesis se centra en evaluar, de manera experimental, los desarrollos teóricos de los controladores propuestos en convertidores de potencia. Concretamente, en la tesis se presentan los resultados experimentales obtenidos con diversos convertidores DC-DC y DC-AC. Adicionalmente, las metodologías y técnicas de implementación de los controladores son, de igual modo, ampliamente descritas.Postprint (published version

Fixed-switching frequency sliding mode control applied to power converters

The application of the sliding mode control in power converters has a well-known inconvenient from the practical point of view, which is to obtain fixed switching frequency implementations. This thesis deals with the development of a hysteresis band controller in charge of fixing the switching frequency of a sliding motion in power electronics applications. The proposed control measures the switching period of the control signal and modifies the hysteresis band of the comparator in order to regulate the switching frequency of the sliding motion. The proposed structure becomes in an additional control loop aside from main control loop implementing the sliding mode controller. In the first part of the thesis, the switching frequency control system is modelled and a design criteria for the control parameters are derived for guaranteeing closed loop stability, under different approaches and taking into account the most expectable working scenarios. In the second part of the thesis, the proposed strategies are applied to several power converters prototypes. Specifically, DC-to-DC and DC-to-AC power converters are built and the experimental results are shown. In this part, the strategies used for implementing the controllers are also deeply discussed.La aplicación del control en modo deslizante en el ámbito de la electrónica de potencia presente una problemática ampliamente conocida, obtener aplicaciones a frecuencia fija de operación. Es esta tesis se estudia el desarrollo de un comparador con histéresis variable encargado de regular el periodo de conmutación de controladores bajo regímenes deslizantes en convertidores de potencia. La estructura propuesta mide el periodo de conmutación de la señal de control y actualiza, de manera adecuada, la banda de histéresis del comparador a tal fin de regular la frecuencia de conmutación al valor deseado. La solución propuesta forma un segundo lazo de control, además del lazo de control principal que implementa el controlador en modo deslizante. En la primera parte de la tesis, éste segundo lazo es modelado, haciendo posible el estudio de las condiciones de estabilidad bajo realizaciones en tiempo continuo y en tiempo discreto. Además, se estudian las condiciones típicas de trabajo de los controladores utilizados en convertidores de potencia, como son los esquemas de regulación y de seguimiento de señales variantes en el tiempo. La segunda parte de la tesis se centra en evaluar, de manera experimental, los desarrollos teóricos de los controladores propuestos en convertidores de potencia. Concretamente, en la tesis se presentan los resultados experimentales obtenidos con diversos convertidores DC-DC y DC-AC. Adicionalmente, las metodologías y técnicas de implementación de los controladores son, de igual modo, ampliamente descritas