Control Design for Electronic Power Converters

A lot of research has recently been focused on converters due to the increasing deal of interest in power electronics. This is mainly caused by their broad applicability domain that includes battery-operating portable equipment, computers, appliances, vehicles, industrial electronic equipment, uninterruptible power supplies, telecommunication systems and much more. This current research is specially focused on finding highly-efficient converter topologies for every system application and, on designing control mechanisms that accomplishes the converter objectives. Among all variety of converters, this thesis is focused on providing a control solution for two converters topologies, which have some interesting properties and applications. The converters that will be dealt with are: firstly, a switch inverter topology; and secondly, a DC-DC converter for low power application. The first application is focused on controlling an SMPC boost inverter. This converter is particularly interesting because it does not only allow generating an alternating current, but it can also obtain an output voltage larger than the input signal. It has a high efficiency due to its switching character. Nevertheless, it has a non-minimum phase, 4th-order model. In addition, the desired behavior is not an equilibrium point but a limit cycle. Due to all the mentioned boost inverter characteristics, the main objective is to design a control law that guarantees not only the convergence to the desired limit cycle, but also the stability of it, with the particularity that no external reference is applied to the system. Likewise, the system has to accomplish right performance not only for known loads, but also for unknown loads. Another important aim is to estimate a set of initial voltage and current values, for which the system variables tend to the desired limit cycles when the control law before is applied to the boost inverter. If all these objectives are achieved, a control system guarantees a stable and robust behavior from an initial condition, which is within an estimated attraction region. And, in addition, the system is autonomous in the sense that no reference signals are needed. The second application deals with the control of a discrete DC-DC Vdd-Hooping converter. This is a low-power converter with a high-efficiency. Furthermore, it has suitable properties, for instance, it is a 1st-order model and its control objective is an equilibrium. Nevertheless, in low-power technology, this low level of efficiency may not become enough if certain requirements are demanded (e.g. high energy-efficiency, small current peaks, fats transient-times and reduced space). For this, to design a control law focused on achieving an optimal energy-efficiency may be an attractive problem. Indeed, the control problem of the Vdd-Hopping converter in this thesis comes directly demanded by the industry. Concretely, it is included in a French national project called ARAVIS, sponsored by the global competitive cluster Minalogic. The main objective of this converter is to guarantee that the system reaches the desired equilibrium point, achieving certain required features as: high-efficiency, stability, low computational cost, robustness with respect to parameter uncertainties and robustness with respect to delays due to synchronization and computation issues. In this way, the control law must be designed taken these objectives into account.