Features of the Switching Regulator Operation оN a Rechargeable Battery

Abstract

In connection with the widespread distribution of non-traditional and renewable sources of electricity, the task is to obtain from them the maximum possible amount of electric energy. As is known, to select from a power source of maximum power, it is necessary that the load impedance is equal to the output impedance of the source (harmonized mode). Under real conditions, the output resistance of the source depends on the external conditions, and the resistance of the load - from the mode of its operation. Therefore, the selection of maximum power from the source is possible only under a certain operating mode of the load. To enable selection from the generator of maximum power, when changing the external conditions and the mode of operation of the load between them include a matching device. As such, most often use switching regulator of voltage. Obviously, in such devices, the source of energy cannot be considered ideal and it is necessary to take into account its internal resistance. By adjusting the output current of the source, we will change the voltage drop on its internal resistance so, that the operating point of the generator is output to its maximum power zone. The internal resistance of the source of electric energy is significantly influence on the basis parameters and characteristics of the switching regulator of voltage. The peculiarity of using switching regulator of voltage as elements of renewable sources is that in order to ensure a even supply of electrical energy to a load, a battery, that works in a buffer mode, is connected in parallel to it. Switching regulator of voltage can also be used to regulate battery charging current in power supplies, electric cars, etc. In all these cases the battery determines the mode of operation of the switching regulator of voltage. Features of the switching regulator of voltage operation on the battery in the buffer mode, taking into account the internal resistances of the voltage source and the battery are analyzed. It is shown that under such conditions, switching regulator of voltage operates in the current regulation mode, but not voltage. Az the example, for switching regulator of voltage of the boost type determined the regulation characteristics for the modes of continuous and intermittent inductor current. It is shown that in order to reduce the dependence of the output voltage on the charging current of the battery, as well as to reduce the power loss therein, it is necessary to provide a certain relationship between the internal resistances of the electric power source and the battery. Graphs of regulation characteristics and the conditions of transmission from the energy source to the battery of the maximum possible power are determined. Recommendations on the application of modes of continuous and intermittent inductor current in the switching regulator of voltage when it operates on the battery are given. Ref. 13, fig. 5, tabl. 2.