Method for energy-saving charging and discharging of cells and system for testing energy-saving charging and discharging of cells

Abstract

The invention relates to the technical field of an energy-saving charging and discharging test on cells, and specially, relates to a method for energy-saving charging and discharging of cells and a system for testing energy-saving charging and discharging of cells. When all cells are in a charging state, power is sent from an electrical network and orderly passes through a direct current-alternating current transformation unit, a direct current-direct current transformation unit and the cells. When all the cells are in a discharging state, power is sent from the cells and orderly passes through the direct current-direct current transformation unit, the direct current-alternating current transformation unit and the electrical network. When cell charging powder and cell discharging powder are unequal, the powder unbalance is adjusted by the direct current-alternating current transformation unit and the electrical network. In the invention, charging and discharging of cells are realized simultaneously. Powder produced by cell discharging is fed back to an electrical network so that powder cyclic utilization is realized and powder-saving effects are obtained. A part of the cells are in a charging state and the other part of the cells are in a discharging state so that powder can be transmitted between the two parts without passing through the electrical network and thus powder cyclic utilization efficiency is improved; powder consumption is reduced; charging-discharging integration is realized; and operation processes are simple and efficient.

Description

technical field [0001] The invention relates to the technical field of battery energy-saving charging and discharging tests, in particular to a battery energy-saving charging and discharging method and a testing system. Background technique [0002] Rechargeable batteries (such as lithium batteries, lead-acid batteries, etc.) usually need two steps of formation and capacity separation before leaving the factory. The so-called formation and capacity separation are to make the chemical substances in the internal plate of the battery Fully activate, and judge the capacity of the battery through the charging and discharging process, and carry out screening and classification. The traditional method of formation and capacity division is to charge the battery by connecting it to a charger, and then discharge it by connecting the battery to a resistor, which consumes a lot of energy, especially for large-capacity batteries. [0003] In the existing technology, most of the domestic...

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Problems solved by technology

[0003]In the existing technology, most of the domestic battery manufacturers still use the original and backward charging and discharging equipment for chemical composition, that is, the charging equipment and the discharging equipment are separated, Charging equipment converts mains electricity into direct current to supply power to batteries. Due to the narrow charging voltage range, it is generally only suitable for several types of batteries; while discharging equipment generally uses resistors as loads to consume the energy of batteries through resistance heating; there is also a A small number of enterprises use the thyristor active inverter discharge device to discharge and send the battery energy back to the grid, but the device has the following defects: 1) It is prone to inverter subversion; 2) The harmonic pollution to the grid is relatively large, and the thyristor The current injected into the grid by the active inverter discharge device is a square wave with large harmonic content; 3) The ripple coefficient of the discharge current is large

[0004] In order to solve the above problems, the Chinese utility model patent No. ZL.200520053515.4 discloses an energy-saving battery charging and discharging system. The way of charging and discharging between the tested batteries realizes energy saving, and the charging and discharging are integrated. The charging and discharging system has the following disadvantages: 1) The power storage device is large in size, and because it is often in the charging and discharging state, its life is short, and it needs to be updated frequently. 2) There is a mismatch between the energy of the power storage device and the energy of the battery under test. When the energy of the battery under test is greater than the energy that the power storage device can absorb, when the battery under test discharges, the power storage device The voltage will be very high, and even burn out the power storage device

[0005] The Chinese invention patent with the patent application number 200710134763.5 discloses a battery charging and discharging main circuit structure, and its technical solution is to use grid-connected inverter technology and non-isolated bidirectional Transformation technology realizes the integration of battery charge and discharge, and realizes the energy saving of discharge, but this method is only suitable for high-voltage batteries (that is, multiple batteries need to be connected in series), and when the battery is formed, it is generally not connected in series. Therefore, the method is not practical

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