Power supplying circuit and power supplying method for chain-type SVG (static var generator) modules

Abstract

The invention relates to a power supplying circuit and a power supplying method for chain-type SVG (static var generator) modules. The power supplying circuit comprises a constant alternating-current control power supply and a plurality of current sensing receiving circuits, and each current sensing receiving circuit consists of a ferrite bead and a coil. An output terminal of the constant alternating-current control power supply is connected with a high-voltage cable, and the high-voltage cable is penetratingly arranged in the ferrite beads of the current sensing receiving circuits to connect the ferrite beads in series structure. Each input terminal of the SVG modules is respectively connected with each output terminal of the current sensing receiving circuits, and the ferrite beads are located outside the SVG modules. The constant alternating-current control power supply comprises a semi-controlled rectifier bridge, an inductor, a direct-current capacitor and a phase-shifting and voltage-regulating inverter bridge. Alternating-current utility power is rectified to direct-current voltage containing ripple components through the semi-controlled rectifier bridge, and current surge is reduced via the inductor, the ripple components in the direct-current voltage are restrained by the direct-current capacitor parallelly connected between two output terminals of the semi-controlled rectifier bridge, and then the alternating-current utility power is inputted into the phase-shifting and voltage-regulating inverter bridge. The power supplying circuit and the power supplying method for the chain-type SVG (static var generator) modules can be widely applied to the field of high-voltage reactive power compensation.

Description

technical field [0001] The invention relates to a high-voltage power supply method and a power supply circuit thereof, in particular to a power supply circuit and a power supply method that can be used for a 35KV direct chain-type SVG (static var generator) module. Background technique [0002] At present, in the field of high-voltage reactive power compensation, SVG (Static Var Generator) is developing in full swing, various technologies are becoming more mature, and there are more and more engineering application cases. Domestic SVGs are mainly chain-type, 6KV and 10KV SVGs are usually directly connected to the power grid, and 35KV is currently more of a transformer step-up method. The chain-type SVG is composed of several unit modules, each unit module is a single-phase voltage inverter, mainly composed of an H-shaped fully-controlled bridge, a DC capacitor and a control circuit board, and the control circuit board communicates with the main control board through optical ...

AI Technical Summary

Problems solved by technology

The power supply of the control circuit board usually adopts a high-voltage isolation transformer, such as the 10KV isolation 220 / 220 type of mains power supply. Due to the limited space of the unit module, the isolation transformer must be as small as possible, so the isolation transformer manufacturers adopt insulation materials. method, but this will lead to the following problems: 1. Since the transformer detection is a destructive test, the qualified rate and detection rate of the isolation transformer are not high, and the scrap rate is very high.

2. The insulating material generates a large parasitic capacitance, which may cause serious interference, which is one of the biggest hidden dangers of instability in SVG's current engineering

3. The incoming lines of the isolation transformer of each unit module are connected in parallel, and the wiring is more complicated

4. The whole set of SVG needs dozens of isolation transformers, which is costly

5. For 35KV direct connection, this method needs to isolate 35KV, the volume is larger, and the feasibility is extremely low

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