Uninterruptible power supply provider

Abstract

The invention relates to an uninterruptible power supply provider, which comprises an input switch circuit, an AC-DC conversion circuit, a bus capacitor, an energy storage unit, a charging circuit, a DC-AC conversion circuit and a system control circuit, wherein the AC-DC conversion circuit is connected between the input switch circuit and a direct current bus, the bus capacitor is connected withthe direct current bus, the energy storage unit is selectively connected with a connecting end and a common connecting end of the energy storage unit, the charging circuit is connected with the inputswitch circuit and the connecting end of the energy storage unit, the DC-AC conversion circuit is connected with the connecting end of the energy storage unit and the direct current bus, and the system control circuit is connected with the input switch circuit, the AC-DC conversion circuit, the charging circuit and the DC-AC conversion circuit to be used for controlling operation and controls theAC-DC conversion circuit to stop operation when the uninterruptible power provider starts so as to enable the DC-AC conversion circuit to charge the bus capacitor. According to the invention, the condition that impact currents exist in the uninterruptible power provider because of overlarge start currents of the uninterruptible power provider can be prevented from occurring.

Description

technical field [0001] The present invention relates to a power supply, in particular to an Uninterruptible Power Supply (UPS). Background technique [0002] With the rapid development of information industry and high-tech industry, most precision electronic instruments and equipment need to rely on high-quality power supply to maintain normal operation. Among various power supply methods, the UPS can not only ensure that the power will not be interrupted, but also provide high-quality power, so the UPS has become the best solution for providing high-quality power today. [0003] A traditional uninterruptible power supply includes an AC-DC conversion circuit, a DC-AC conversion circuit, and a bus capacitor, wherein the output end of the AC-DC conversion circuit is connected to the bus capacitor and the input end of the DC-AC conversion circuit to convert the AC The input voltage is converted to a DC voltage and a bus voltage is generated on the DC bus, and the bus capacitor...

AI Technical Summary

Problems solved by technology

[0008] However, although the thermistor can reduce the start-up current, it also consumes unnecessary power, which reduces the overall efficiency of the UPS

Furthermore, the resistance value of the thermistor needs to be properly adjusted according to the capacitance value of the bus capacitor. However, the bus capacitor generally uses an electrolytic capacitor with a large capacitance error. The error value of the bus capacitor makes the actual capacitance value of the bus capacitor not correspond to the thermistor with the appropriate resistance value, so the thermistor cannot effectively reduce the startup current

[0009] In addition, the phase adjustment circuit can only adjust the phase of the AC input voltage transmitted to the AC-DC conversion circuit, and cannot control the magnitude of the input current when the phase is turned on. The magnitude of the current when the phase is turned on changes with the voltage value of the AC input voltage , and the phase adjustment circuit composed of the silicon controlled rectifier cannot cut off the silicon controlled rectifier of the phase adjustment circuit through the phase control circuit after the silicon controlled rectifier is turned on, so the starting current cannot be accurately reduced

However, the complexity of the phase control circuit is high, which makes the stability of the phase control circuit relatively low, which in turn causes the overall stability of the uninterruptible power supply to be low.

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