A distribution network voltage sag control device and its control method

Abstract

The invention discloses a distribution network voltage sag control device and a control method thereof. The distribution network voltage sag treatment device of the present invention includes a main body, a power supply on one side of the main body and a load on the other side of the main body, the main body includes a diode, a first IGBT, a second IGBT, a third IGBT, a capacitor, Resistor and inductor, the diode, resistor, inductor, second IGBT, third IGBT and first IGBT are connected in series in sequence; one end of the capacitor is connected to the circuit between the inductor and the second IGBT, and the other end is connected to the second IGBT On the circuit between the three IGBTs and the second IGBT; the power supply is a three-phase power supply, one of which is connected to the emitter of the first IGBT, the other phase is connected to the anode of the diode, and this phase is also connected to the second IGBT and the circuit connection between the third IGBT. The voltage sag control device of the invention can realize the physical isolation between the power supply and the load, and at the same time can realize the support of the load voltage after the AC system fails.

Description

technical field [0001] The invention belongs to voltage sag control equipment, in particular to a distribution network voltage sag control device and a control method thereof. Background technique [0002] In the AC distribution network, when the line or equipment between the AC power supply and the load fails, it is easy to cause AC voltage sags. Such sags are likely to have adverse effects on the operation of loads, especially voltage-sensitive loads. For example, chip manufacturers , Textile enterprises, will cause huge economic losses. [0003] At present, conventional solutions to control voltage sag at home and abroad mainly include: uninterruptible power supply (UPS), dynamic voltage restorer (DVR) and solid-state transfer switch (SSTS). The comparison of the solutions is as follows: [0004] (1) UPS is usually the first solution that comes to mind, but the power of this device is generally small, usually based on low voltage, and it is mainly suitable for enterprise...

AI Technical Summary

Problems solved by technology

If the sensitive load of the enterprise accounts for a large proportion, production line level or even the whole plant level management can be considered. At this time, a high-power UPS (or DUPS) or even a high-voltage high-power UPS (or DUPS) is required, and the corresponding cost will be very high. At the same time, it also involves regular maintenance and replacement of batteries.

[0005] (2) DVR has a relatively strong price advantage compared with UPS in dealing with voltage sags, but it has its own fatal flaw, that is, when the grid voltage drops below 50%, or is completely interrupted, DVR has been unable to effectively compensate , useless

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