Step-up/step-down regulators in maximum power transmission mode
Authors: Romashko V. Y. , Batrak L. M. , Abakumova O. O. 
Published: April 2022

Introduction. Switching DC voltage regulators are traditionally used to regulate and stabilize the voltage on the load. Due to the widespread use of non-traditional and renewable sources of electricity, there is a need to select from them the maximum possible amount of electricity. As is known, the maximum power from the power supply to the load will be transmitted provided that the output resistance of the source is equal to the load resistance. If this condition is not met, a matching switching regulator is switched on between the power supply and the load. Most often, for the purpose of matching, pulse regulators of step-up or step-down types are used. Problem. The operation of regulators in the matching mode has a number of features, in comparison with the modes of regulation and stabilization of the output voltage. Thus, since in the maximum power transmission mode the output resistance of the source and the resistance of the load are values of the same order, in any calculation the internal resistance of the source must be taken into account. There are works in which features of work of regulators of step-up and step-down types in a mode of transfer of the maximum power are analyzed. In addition to these types of pulse regulators, there are regulators of step-up/step-down types, which are relatively rarely used for this purpose. First of all it is connected with insufficiently studied abilities of work of such regulators in the specified mode. Goal. The aim of the work is to analyze the features of the operation of pulse regulators of step-up/step-down types in the mode of transmission of maximum power from the power supply to the load, as well as to determine the conditions under which it is possible and appropriate to work in this mode. Methodology. In the work, taking into account the internal resistance of the power supply, the regulation characteristics of the basic circuit of the pulse regulator of the step-up/step-down type are analyzed. The conditions under which the transfer of maximum power from the power supply to the load is ensured are determined. Results. It is shown that the existing variants of the circuits of regulators of the step-up/step-down type can be obtained from the basic circuit by applying the rules of construction of dual electric circuits. Consequently, the basic calculated relations for such circuits can be obtained from the calculated relations of the basic circuit using the principle of duality. Originality. A method for determining and studying the regulation characteristics of pulse regulators, taking into account the internal resistance of the power supply. Practical value. The obtained results allow to determine the conditions under which it is possible and expedient to operate different circuits of regulators in the mode of transmission of maximum power from the power supply to the load. Based on these results, recommendations are given for selecting a suitable range for changing the relative time of the closed state of the controlled switch, depending on the type of power supply used, as well as the method of connecting the controlled switch in the regulator circuit.