Pulsed voltage regulator with digital control for autonomous power supply system

Abstract

Relevance. The efficiency and effectiveness of geophysical survey, geological work, meteorological observation and environmental monitoring depend on the power supply systems of testing and research equipment. Specificity of such works implies the use of field autonomous systems. Primary energy sources in such systems, as a rule, are renewable energy sources, such as solar batteries, wind or hydroelectric power plant, and secondary sources of energy are accumulator batteries. Energy sources are combined into a power supply system using pulse energy converters, which provide transferring energy and stabilizing supply voltage for consumers. An important function of pulse energy converters is increasing the energy efficiency of primary energy sources by means of their exploiting in the mode of generating maximum power. Consumers of autonomous power supply system are a complex and heterogeneous equipment, often having an impulse mode of energy consumption. This leads to significant voltage deviations on output buses of the power supply system and mutual influence of separate consumers and may cause malfunctions in their operation. Pulse energy converters must provide voltage stabilization on output buses. In the mode of maximum power generation, the pulse converter control unit provides conversion and holding of the operating point on the power characteristic of the primary source within the maximum power. The control unit implements a rather complicated algorithm of extreme control. At the modern level of technology development, the control unit is developed on the basis of a programmable digital device. The use of the same programmable digital control device for the mode of voltage stabilization on output buses is an actual task. This solution will reduce the complication of the converter control unit, decrease its own power consumption and improve operation reliability. The aim of the work is to solve the theoretical and practical tasks of ensuring digital control with the pulse converter in stabilization mode of output tension ensuring small duration of transients caused by of loading current increment and output tension astatism. Methods: theory of pulsed automatic control systems, mathematical modeling of processes in switching voltage regulators and physical prototyping. Results. The authors have analyzed the features of autonomous power supply systems, synthesized the control law and developed the model of the pulse voltage stabilizer. The proposed method of the switching voltage regulator control provides the minimal transient duration. Microprogramming control algorithms are designed on the base of the specified control method. The authors developed the architecture of the microprocessor control system and built/in software and implemented a single/chip computing module of the control system using a programmable integrated circuit as well as a prototype of the switching voltage regulator with the digital control unit on the base of the single/chip computational module. A case study of the prototype shows the effectiveness of the developed control system. It is shown that the developed control system provides the minimum transient finite duration caused by a step change in the load current equal to two conversion periods. The test results confirmed that a fully digital control loop on the base of a high/speed micro/ processor unit for switching voltage regulators has significant advantages over analog implementations.