Parallel uninterrupted power supply circuit

Abstract

The invention discloses a parallel uninterrupted power supply circuit, which comprises a neutral line, a battery, a plurality of PFC boost converters, a rectifier bridge, a switch bridge, a control switch and an inverter, wherein the battery is provided with a positive pole and a negative pole; each PFC boost converter comprises a power factor correction circuit; the power factor correction circuit comprises an inductor which is provided with a first end and a second end; the first end is coupled to the positive pole; the rectifier bridge comprises a first shunt diode and a second shunt diodewhich are coupled to a first central point and is provided with a first end and a second end, wherein the first central point is coupled to the second end of the inductor, and the second end is coupled to the negative pole; the switch bridge comprises an upper switch and a lower switch which are coupled to a second central point and is provided with a first end and a second end, wherein the firstend is coupled to the first end of the rectifier bridge; and the second end is coupled to the second end of the rectifier bridge; and the control switch is coupled to the neutral line of the second central point.

Description

technical field [0001] The invention discloses a parallel uninterrupted power supply (uninterrupted power supply: UPS) circuit, and particularly relates to a parallel connection of a plurality of uninterrupted power supplies to the same battery pack so that the plurality of uninterrupted power supplies can achieve current sharing among each other. circuit. Background technique [0002] Uninterruptible power supply is used in key equipment power supply system, figure 1 It is a typical online (online) UPS system circuit diagram. The UPS system includes a power factor correction (PFC) boost converter (including silicon controlled rectifiers SCR1-SCR2, inductors L1-L2, switches S1-S2, diodes D1-D2 and capacitors C1-C2), an inverter device (including switches Si1-Si2, inductor Li and output capacitor Co), a controller (not shown) and battery pack (which includes a battery with positive and negative poles, silicon controlled rectifiers SCR3-SCR4 and fuse F2); in addition the Th...

AI Technical Summary

Problems solved by technology

The parameters of inductors L1 and L2 are related to the manufacturing process, materials, etc., and it is difficult to achieve the same parameters

Moreover, magnetic components such as inductors are made of mineral materials such as copper and iron. With the development of the economy, their costs will become higher and higher.

In this way, the current flowing through the inductor in each UPS module is difficult to be controlled independently, which makes the input power of each UPS unequal, resulting in inductor current oscillation and uneven current of the switch, and the parallel connection of multiple UPS modules in a single battery pack will also cause can not achieve

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