Full-bridge switch characteristic current generating device applied to power industry

Abstract

The invention discloses a full-bridge switch characteristic current generating device applied to the power industry. The full-bridge switch characteristic current generating device comprises an energy storage inductor L1, a safety capacitor C1 for filtering, an electrolytic capacitor C2 for storing energy, MOS tubes Q1 and Q2, and MOS tubes Q3 and Q4, wherein the MOS tubes Q3 and Q4 are used for selecting a working mode of a power supply; the first end of the C1 and the first end of the L1 are connected to the live wire of a power grid, the second end of the L1 is connected with the source electrode of the Q4 and the drain electrode of the Q1; the drain electrode of the Q4 is connected with the drain electrode of the Q2 and the anode of the C2; the second end of the C1, the source electrode of the Q3 and the drain electrode of the Q2 are connected to the zero wire of the power grid; and the source electrode of the Q1 is connected with the source electrode of the Q2 and the cathode of the C2. According to the device of the invention, on the basis of ensuring phase identification accuracy, the generation of nearly lossless characteristic current is realized in a mode of making a BUCK circuit and a BOOST circuit alternately work, and therefore, the power conversion efficiency is higher, the line loss is effectively reduced, the safety of a line is improved, and the engineering practicability is very strong.

Description

technical field [0001] The invention relates to the technical field of phase identification, in particular to a full-bridge switch characteristic current generating device used in the electric power industry. Background technique [0002] When the three-phase lines of the low-voltage distribution network are extended to the user's end for wiring, it is often difficult to distinguish phases A, B, and C, so they can only be wired casually. In this case, the unbalanced power consumption of the three phases will easily lead to the overload of one phase or two phases, resulting in unbalanced three-phase current, increasing line loss, and may even cause the transformer to burn out and cause a fire. Therefore, the need for phase identification Came into being. In order to realize phase identification, the commonly used method today is to inject a characteristic current signal of a certain frequency into the power line, and the signal receiving end judges the phase by analyzing the...

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Problems solved by technology

[0003] At present, there are two common schemes for characteristic current injection: 1. Resistor switching scheme, this scheme is based on the switching resistance connected in parallel in the line to generate the characteristic current, but the problem is that the existence of the switching resistance causes the power of this part 2. The capacitor switching scheme, the power grid first charges the switching capacitors connected in parallel in the line, and converts the charged electric energy into a characteristic current and injects it into the power line for analysis. There is no power loss in the whole process, but this The amplitude of the current injected by the solution is limited, the analyzed features are not obvious enough, and it is easily disturbed by the noise of the power grid, resulting in relatively insufficient recognition accuracy

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