Nickel-metal hydride battery charge-discharge circuit in uninterruptible power supply

Abstract

The invention discloses a nickel-metal hydride battery charge-discharge circuit in an uninterruptible power supply. The nickel-metal hydride battery charge-discharge circuit in the uninterruptible power supply comprises a charger, a discharge diode and a charge and discharge control circuit; the charge and discharge control circuit comprises a singlechip, a charging relay and a charging MOS (metal oxide semiconductor) tube; the charger charges a nickel-metal hydride battery through the normally open contact of the charging relay and is connected with the input end of a direct-current booster of the uninterruptible power supply through the normally closed contact of the charging relay; the control signal input end of the charger is connected with the output port of the singlechip; the charging MOS tube controls a charging relay control coil; the gate of the charging MOS tube is connected with the output port of the singlechip; the output voltage of the nickel-metal hydride battery is connected with a voltage sampling port of the singlechip after being subjected to partial pressure by a first resistor and a second resistor; a third resistor is connected in series between the cathode of the nickel-metal hydride battery and the output ground of the charger; the output signal of the third resistor is connected with a current sampling port of the singlechip; and the nickel-metal hydride battery supplies power to an inverter through the discharge diode. By the nickel-metal hydride battery charge-discharge circuit in the uninterruptible power supply, charging frequency is greatly reduced, so that the service life of the nickel-metal hydride battery is prolonged, and the operation cost and the maintenance cost of the uninterruptible power supply are reduced.

Description

technical field [0001] The invention relates to a battery charging circuit capable of preventing frequent charging and discharging of nickel-metal hydride batteries inside an uninterruptible power supply, belonging to the technical field of power supplies. Background technique [0002] Since lead-acid batteries and lithium batteries cannot be discharged at high currents at low temperatures, nickel-metal hydride batteries are generally required for uninterruptible power supplies that work in low-temperature environments. The charging method of Ni-MH batteries is different from that of lead-acid batteries and lithium batteries. It cannot be floated and charged for a long time, and can only be charged by constant current. The current constant current charger of the uninterruptible power supply will stop working after the battery is fully charged. It has been in a low current discharge state, which shortens the charging cycle of the Ni-MH battery and increases the charging freq...

AI Technical Summary

Problems solved by technology

The charging method of Ni-MH batteries is different from that of lead-acid batteries and lithium batteries. It cannot be floated for a long time and can only be charged by constant current.

The current constant current charger of the uninterruptible power supply will stop working after the battery is fully charged. It has been in the state of low current discharge, which shortens the charging cycle of the Ni-MH battery and increases the charging frequency, which greatly reduces the service life of the Ni-MH battery and increases the operation and maintenance costs of the uninterruptible power supply.

Images