Direct-current voltage reducing circuit

Abstract

The invention provides a direct-current voltage reducing circuit. Anode of a battery direct-current bus is sequentially connected with a second switching element, an energy storing inductor, a first switching element and cathode of the battery direct-current bus to form the energy storing circuit loop; cathode of a battery unit is connected with anode of a second diode, cathode of the second diodeis connected with anode of a first diode through the energy storing inductor, cathode of the first diode is connected with anode of the battery unit, so as to form a voltage reducing discharge loop;a control circuit controls state of the first and the second switching elements to alternatively and repeatedly carry out synchronous switch-on and switch-off operation. The invention has advantages as follows: exchange between direct current and alternative current does not need, energy loss in voltage reducing process of isolating transformer is avoided, the circuit has simple structure, low cost and high efficiency; when the circuit is applied to management of balancing electric quantity of batteries connected serially, a battery unit is corresponding to a voltage reducing circuit, works independently and modularly and has high reliability; the control of voltage reducing proportion is flexible; standard and batch production can be realized.

Description

technical field [0001] The invention belongs to the technical field of direct current step-down circuits, in particular to a direct-current step-down circuit for power balance of series battery packs, and in particular to a step-down circuit for non-energy consumption real-time equalization technology of power battery packs. Background technique [0002] With the application of batteries with large capacity density and high power density becoming more and more common, the balancing technology of battery packs has become the main task of the battery management system. Currently the most widely used lead-acid batteries, nickel-metal hydride batteries and lithium-ion batteries all have inconsistencies between unit cells. Due to the difference in the production process, the performance change in the use process and some other factors, this difference cannot be completely eliminated. When the battery pack is used in occasions that require frequent charge and discharge cycles, su...

AI Technical Summary

Problems solved by technology

The main disadvantages of the isolation transformer method are low power transfer efficiency, many circuit components, complex modules, high cost and low reliability

The disadvantage of the step-by-step transfer method is that the number of electric energy conversions is large, the energy loss is large, and the equalization efficiency is low.

At the same time, because the power transfer is a step-by-step transfer relationship, if a module fails, the equalization effect of the entire system will be significantly reduced, reducing the reliability of the system

Images