Esta tese apresenta uma estratégia de controle para gerenciar a potência entregue ou absorvida da rede, independente de características das cargas locais. Para atingir este objetivo é utilizado um inversor fonte de tensão (VSI) que funcionará semelhante a um sistema de geração distribuída (GD) ou como um filtro ativo. O VSI é controlado por meio de controladores clássicos em cascata, nos quais a malha interna é utilizado para estabilizar a corrente e a malha externa controla a tensão nos terminais de saída da GD. Para melhorar a resposta do VSI são colocados filtros ressonantes em paralelo ao controlador de tensão (P+RES). Além disso, as respostas dos filtros ressonantes são melhoradas através da utilização de um método adequado de discretização, no qual os coeficientes são alterados dinamicamente mediante a frequência de sincronismo produzido pelo algoritmo de sincronismo (PLL). O controle de potência apresenta duas estruturas de controle em malha fechada: uma para controlar a potência reativa através da rede pelo ajuste da amplitude da tensão da GD, e o outra para controlar a potência ativa, modificando o ângulo de defasagem entre as tensões da rede e as tensões GD. Por fim, um conjunto de simulações e resultados experimentais é apresentado para validar todas as propostas deste trabalho. / This thesis presents a control strategy to manage the power delivered to or absorbed from the grid, independently of the local load characteristics. To achieve this goal, a voltage source inverter (VSI) will work as a distributed generation system (DG) or according to active filter. The VSI will be controlled by means of a double cascade classical controller, in which the inner loop is used to stabilize the VSI output current and the outer loop controls the DG terminal voltage. To improve the response of the VSI, resonant filters are placed in parallel. Additionally, resonant filter dynamic responses are enhanced through the use of a proper discretization method, in which the coefficients are changed dynamically by means of the synchronism frequency produced by the phase-locked loop (PLL) algorithm. This study also exhibits two closed-loop structures: one to control the reactive power through the grid by adjusting the DG voltage amplitude, and the other to control the active power by modifying the angle of displacement between the grid and the DG voltages. Both power control structures operate adequately in decoupled operation mode, so that one has a faster dynamic response than the other. To verify all statements proposed in this thesis, a set of simulations and experimental results are presented.

Esta tese apresenta uma estratégia de controle para gerenciar a potência entregue ou absorvida da rede, independente de características das cargas locais. Para atingir este objetivo é utilizado um inversor fonte de tensão (VSI) que funcionará semelhante a um sistema de geração distribuída (GD) ou como um filtro ativo. O VSI é controlado por meio de controladores clássicos em cascata, nos quais a malha interna é utilizado para estabilizar a corrente e a malha externa controla a tensão nos terminais de saída da GD. Para melhorar a resposta do VSI são colocados filtros ressonantes em paralelo ao controlador de tensão (P+RES). Além disso, as respostas dos filtros ressonantes são melhoradas através da utilização de um método adequado de discretização, no qual os coeficientes são alterados dinamicamente mediante a frequência de sincronismo produzido pelo algoritmo de sincronismo (PLL). O controle de potência apresenta duas estruturas de controle em malha fechada: uma para controlar a potência reativa através da rede pelo ajuste da amplitude da tensão da GD, e o outra para controlar a potência ativa, modificando o ângulo de defasagem entre as tensões da rede e as tensões GD. Por fim, um conjunto de simulações e resultados experimentais é apresentado para validar todas as propostas deste trabalho. / This thesis presents a control strategy to manage the power delivered to or absorbed from the grid, independently of the local load characteristics. To achieve this goal, a voltage source inverter (VSI) will work as a distributed generation system (DG) or according to active filter. The VSI will be controlled by means of a double cascade classical controller, in which the inner loop is used to stabilize the VSI output current and the outer loop controls the DG terminal voltage. To improve the response of the VSI, resonant filters are placed in parallel. Additionally, resonant filter dynamic responses are enhanced through the use of a proper discretization method, in which the coefficients are changed dynamically by means of the synchronism frequency produced by the phase-locked loop (PLL) algorithm. This study also exhibits two closed-loop structures: one to control the reactive power through the grid by adjusting the DG voltage amplitude, and the other to control the active power by modifying the angle of displacement between the grid and the DG voltages. Both power control structures operate adequately in decoupled operation mode, so that one has a faster dynamic response than the other. To verify all statements proposed in this thesis, a set of simulations and experimental results are presented.

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This work demonstrates the capability of a power electronic based power hardware-inthe- loop (PHIL) platform to emulate electric machines for the purpose of a motor drive testbench with a particular focus on induction machine emulation. PHIL presents advantages over full-hardware testing of motor drives as the PHIL platform can save space and cost that comes from the physical construction of multiple electric machine test configurations. This thesis presents real-time models that were developed for the purpose of PHIL emulation. Additionally, real-time modeling considerations are presented as well as the modeling considerations that stem from implementing the model in a PHIL testbench. Next, the design and implementation of the PHIL testbench is detailed. This thesis describes the design of the interface inductor between the motor drive and the emulation platform. Additionally, practical implementation challenges such as common mode and ground loop noise are discussed and solutions are presented. Finally, experimental validation of the modeling and emulation of the induction machine is presented and the performance of the machine emulation testbench is discussed. / Master of Science / According to the International Energy Agency (IEA), electric power usage is increasing across all sectors, and particularly in the transportation sector [1]. This increase is apparent in one's daily life through the increase of electric vehicles on the road. Power electronics convert electricity in one form to electricity in another form. This conversion of power is playing an increasingly important role in society because examples of this conversion include converting the dc voltage of a battery to ac voltage in an electric car or the conversion of the ac power grid to dc to power a laptop. Additionally, even within an electric car, power converters transform the battery's electric power from a higher dc voltage into lower voltage dc power to supply the entertainment system and into ac power to drive the car's motor. The electrification of the transportation sector is leading to an increase in the amount of electric energy that is being consumed and processed through power electronics. As was illustrated in the previous examples of electric cars, the application of power electronics is very wide and thus requires different testbenches for the many different applications. While some industries are used to power electronics and testing converters, transportation electrification is increasing the number of companies and industries that are using power electronics and electric machines. As industry is shifting towards these new technologies, it is a prime opportunity to change the way that high power testing is done for electric machines and power converters. Traditional testing methods are potentially dangerous and lack the flexibility that is required to test a wide variety of machines and drives. Power hardware-in-the-loop (PHIL) testing presents a safe and adaptable solution to high power testing of electric machines. Traditionally, electric machines were primarily used in heavy industry such as milling, processing, and pumping applications. These applications, and other applications such as an electric motor in a car or plane are called motor drive systems. Regardless of the particular application of the motor drive system, there are generally three parts: a dc source, an inverter, and the electric machine. In most applications, other than cars which have a dc battery, the dc source is a power electronic converter called a rectifier which converts ac electricity from the grid to dc for the motor drive. Next, the motor drive converts the dc electricity from the first stage to a controlled ac output to drive the electric machine. Finally, the electric machine itself is the final piece of the electrical system and converts the electrical energy to mechanical energy which can drive a fan, belt, or axle. The fact that this motor drive system can be generalized and applied to a wide range of applications makes its study particularly interesting. PHIL simplifies testing of these motor drive systems by allowing the inverter to connect directly to a machine emulator which is able to replicate a variety of loads. Furthermore, this work demonstrates the capability of PHIL to emulate both the induction machine load as well as the dc source by considering several rectifier topologies without any significant adjustments from the machine emulation platform. This thesis demonstrates the capabilities of the EGSTON Power Electronics GmbH COMPISO System Unit to emulate motor drive systems to allow for safer, more flexible motor drive system testing. The main goal of this thesis is to demonstrate an accurate PHIL emulation of a induction machine and to provide validation of the emulation results through comparison with an induction machine.

La presente tesis estudia, propone y realiza sus principales aportaciones en el campo del control para el convertidor CC/CA de tres niveles, sobre la topología denominada Neutral-Point-Clamped, aunque se puede extender a otras topologías y/o número de niveles. Se presenta una metodología de modelado que emplea funciones de conmutación de fase, el operador de promediado y la transformación D-Q, tal que los modelos obtenidos en el dominio D-Q contienen una información completa sobre la dinámica del sistema. La estrategia de conmutación se puede entender como una extensión de la estrategia PWM senoidal de dos a tres niveles. Esta estrategia es simple y no realiza el control de ninguna de las variables del sistema. En esta tesis, el controlador se encarga de regular todas las variables del sistema, incluido el equilibrio del bus de continua. Este es un enfoque diferente del convencional, donde el equilibrio del bus de continua se consigue mediante la elección adecuada de los estados redundantes del convertidor en la estrategia de conmutación, mientras que el resto de variables se regulan a través del controlador. Para la realización del controlador, se propone la técnica de control lineal multivariable LQR (Linear Quadratic Regulator), complementada con la técnica de control no lineal adaptativo denominada programación de ganancia (Gain Scheduling). Se presenta, además, una metodología de cálculo del controlador. Este control es versátil, abierto y adaptable. En cualquier caso, el controlador se puede adaptar a las necesidades concretas de cada aplicación. El cálculo del controlador se realiza mediante simulación con MatLab-Simulink. Los modelos matemáticos que emplean las funciones de conmutación del convertidor son aquellos que ofrecen un mejor compromiso entre velocidad de simulación y precisión. Para validar el control propuesto, se ha diseñado y construido un equipo experimental donde el controlador se ha mostrado aplicable, útil y eficaz en la regulación de las distintas cargas y aplicaciones experimentadas, incluso con carga no lineal, bajo diferentes condiciones de trabajo y variables a controlar, tanto en régimen permanente como en procesos transitorios. La rapidez y calidad de la respuesta transitoria es comparable a la de otros sistemas de control publicados. Es especialmente interesante el excelente control conseguido del equilibrio del bus de continua. Además, la robustez del control permite cancelar el error estacionario aunque diferentes parámetros del sistema presenten desviaciones significativas respecto los valores esperados. El uso de la programación de ganancia junto con la técnica LQR se ha mostrado muy efectivo, puesto que permite realizar diferentes tipos de control. Se ha comprobado la congruencia entre simulaciones y resultados experimentales obtenidos, lo que valida los modelos de simulación empleados y el proceso de diseño del controlador mediante simulación. / This dissertation study, propose and carry out the main contributions in the field of three-level inverter control, using the topology Neutral-Point-Clamped, although results can be extended to other topologies and/or number of levels. A procedure for modelling is presented, based on line-switching functions, moving average operator and D-Q transformation. Then, the obtained models in D-Q frame contain complete information about system dynamics. Switching strategy is simple and can be considered as an extension of two-level sinusoidal PWM to three level. The system variables are not controlled by the switching strategy. In this work, all the system variables are controlled by the regulator, including DC-link balance. This control approach is different than the conventional one, where DC-link balance is achieved by means of a proper selection of redundant states in the switching strategy, and the other variables are controlled by the regulator. The regulator is based on the multivariable linear control technique LQR (Linear Quadratic Regulator), in combination with the non-linear adaptive control technique Gain Scheduling. Moreover, a methodology for the calculation of the controller is presented. This controller is versatile, open and adaptable. However, the controller can be built depending on the concrete specifications of each application. The controller is calculated by means of simulation using MatLab-Simulink. The mathematical models based on the switching functions of the converter give the best trade-off between simulation speed and precision. In order to validate the proposed controller, an experimental prototype has been designed and implemented. Experimental results show that the controller is useful and effective for the regulation of different loads and applications, even with non-linear loads, different operation points and variables to control, in steady-state and transitory operation. Dynamic response speed and quality are similar to other control systems in the literature. The DC-link balance control achieved is specially interesting. Furthermore, steady-state error is cancelled due to the robustness of the controller, even though significant deviation of different system parameters are present. The use of Gain-Scheduling in combination with LQR is effective, allowing the calculation of regulators with different control strategies. Good agreement between simulations and experimental results has been found. This result validates simulation models and the design method for the controller, based on simulations.