Analysis of multi-sampled pulsewidth modulation and its application in grid-tied converters

Power electronic systems are essential parts of most modern technologies that depend on converting electrical energy from one form to another. One of such applications is the electric power grid, where more and more grid-tied converters are present, bringing a true paradigm shift in the generation, transmission, distribution, and consumption of electricity. To enable their highly-sophisticated usage as energy-processors, power electronic converters are actively controlled. For a set hardware design, it is the task of the control system to enable highest dynamic performance, which determines the overall system capabilities. The actuation of any power electronic converter is determined by the modulation strategy, which dynamically adjusts its switching states in order to achieve the desired system behavior. Nowadays, power electronic control systems are typically implemented within digital control platforms, as they offer much higher levels of flexibility and unmatched regulation capacities with respect to analog control systems. However, significant demerits of digital control are the associated delays, which are not present when using analog controllers. The focus of this dissertation is the multi-sampled pulsewidth modulation (MS-PWM), which relies on executing the control action more than twice per modulation period with a target of achieving analog-like dynamic performance while retaining all the benefits of the digital control systems. This dissertation brings the analysis of some fundamental aspects of this modulation strategy, as well as an investigation of its applicability in grid-tied power electronic converters.Power electronic systems are essential parts of most modern technologies that depend on converting electrical energy from one form to another. One of such applications is the electric power grid, where more and more grid-tied converters are present, bringing a true paradigm shift in the generation, transmission, distribution, and consumption of electricity. To enable their highly-sophisticated usage as energy-processors, power electronic converters are actively controlled. For a set hardware design, it is the task of the control system to enable highest dynamic performance, which determines the overall system capabilities. The actuation of any power electronic converter is determined by the modulation strategy, which dynamically adjusts its switching states in order to achieve the desired system behavior. Nowadays, power electronic control systems are typically implemented within digital control platforms, as they offer much higher levels of flexibility and unmatched regulation capacities with respect to analog control systems. However, significant demerits of digital control are the associated delays, which are not present when using analog controllers. The focus of this dissertation is the multi-sampled pulsewidth modulation (MS-PWM), which relies on executing the control action more than twice per modulation period with a target of achieving analog-like dynamic performance while retaining all the benefits of the digital control systems. This dissertation brings the analysis of some fundamental aspects of this modulation strategy, as well as an investigation of its applicability in grid-tied power electronic converters