CN203617717U

CN203617717U - SVC feedback circuit used for multiple power supplies

Info

Publication number: CN203617717U
Application number: CN201320724324.0U
Authority: CN
Inventors: 周旭; 方玉珍
Original assignee: Nanjing Iron and Steel Co Ltd
Current assignee: Nanjing Iron and Steel Co Ltd
Priority date: 2013-11-15
Filing date: 2013-11-15
Publication date: 2014-05-28
Anticipated expiration: 2023-11-15

Abstract

The utility model relates to a circuit and especially relates to a SVC feedback circuit used for multiple power supplies. The circuit comprises at least two independent power supplies, a bus and a SVC apparatus. The independent power supplies and the SVC apparatus are connected to the bus respectively. Each independent power supply is provided with a control cable connected to a SVC apparatus current sampling loop. According to the circuit of the utility model, through reconstruction of currents of different power supplies which access the SVC apparatus current sampling loop, switching of a feedback current loop can be performed under the condition that a transformer and a SVC system do not in a power outage state; simultaneously, a secondary winding loop of an inlet wire current transformer is guaranteed not to generate an open circuit condition during the switching process; no matter which main transformer an electric-arc furnace operates in, the SVC apparatus can operate stably; optimal dynamic reactive compensation is provided and electric energy quality is guaranteed to satisfy a national standard specification.

Description

A kind of SVC feedback circuit for many power supplys

Technical field

The utility model relates to a kind of circuit, is specifically a kind of SVC feedback circuit for many power supplys.

Background technology

SVC(Static Var Compensator)---Static Var Compensator, it is static for the slewing such as generator, compensator.It can change idle that it sends fast, has stronger idle regulating power, can be electric power system dynamic reactive power supply, regulating system voltage are provided, and can export capacitive reactive power when system voltage is lower, when heavy load; When system voltage is higher, that the light hours can be exported perception is idle, and supply power voltage is compensated to a reasonable level; SVC exerts oneself by dynamic adjustments is idle, and the busbar voltage causing when the operation of oscillation suppression impact load changes, and is conducive to transient voltage and recovers, and improves system voltage maintenance level;

The setting of the current sampling circuit of conventional SVC device as shown in Figure 1, current sampling circuit is connected directly to one end near arc furnace line (power consumption equipment) on bus 100, this setup can be monitored the behaviour in service of power supply 1101 very easily, once need to use another one power supply 1201 but situation appears in power supply 1101, or when mother disconnects and two-way power supply is powered simultaneously, now lack the feedback quantity of power supply 1201 due to SVC device, SVC device cannot carry out the automatic calculating of reactive balance, cause reactive power compensation amount dynamically to adjust generation entanglement, SVC device cannot normally move at all, while causing electric arc furnace smelting thus, system power factor is very low, voltage fluctuation is large, other user's power quality is greatly affected.

Utility model content

Technical problem to be solved in the utility model is, overcome the shortcoming of prior art, provide a kind of simple in structure, simple installation, easy to operate transform pattern, guarantee that a set of SVC device goes for the operating condition of multiple different electrical power, guarantees good reactive-load dynamic compensation effect.

In order to solve above technical problem, the utility model provides a kind of SVC feedback circuit for many power supplys, comprise at least two independent current sources, bus and SVC device, independent current source and SVC device are connected on described bus, and each independent current source is provided with a control cables that is connected to SVC device current sampling circuit.

The technical scheme that the utility model further limits is:

Further, independent current source comprises power supply, transformer and the incoming line cabinet that order is electrically connected, and described incoming line cabinet is connected with bus by cable, and described SVC device current sampling circuit is connected into incoming line cabinet by control cables.

Further, the bus between two adjacent incoming line cabinets is provided with mother.

Further, one group of conversion connecting valve and one group of shorting switch are all housed on every described control cables.

Further, control cables is band screen cable.

The beneficial effects of the utility model are: the utility model is by the transformation of the electric current access SVC device current sampling circuit of different electrical power, can in the situation that not having a power failure, transformer and SVC system carry out the switching in feedback current loop, guarantee that open circuit situation does not appear in inlet wire current instrument transformer secondary winding loop in handoff procedure simultaneously, no matter arc furnace runs on any main transformer, SVC device all can stable operation, best reactive-load dynamic compensation is provided, guarantee that the quality of power supply meets gb specification, the utility model SVC device is applicable to the feedback loop transformation of different electrical power, wiring is simple, easy construction, improvement cost drops into little.

Accompanying drawing explanation

Fig. 1 is the main circuit schematic diagram before revising.

Fig. 2 is main circuit schematic diagram of the present utility model.

Fig. 3 is the connecting circuit schematic diagram of SVC and two-way power supply.

Embodiment

embodiment 1

A kind of SVC feedback circuit for 2 road power supplys that the present embodiment provides, as Fig. 2, 1 road power supply comprises the power supply 101 of order Electricity Federation, No. 1 transformer and 1101 wiring cabinets, in the bus of 1101 wiring cabinet access 35kV, 2 same road power supplys comprise the power supply 102 of order Electricity Federation, No. 2 transformers and 1201 wiring cabinets, in the bus of 1201 wiring cabinet access 35kV, on the bus between two wiring cabinets, be provided with mother 100,

electricity consumption end

1103, 1202 and 1203 are connected on the bus of 35kV, in the time that mother 100 disconnects, 1 road power supply and 2 road power supplys can provide respectively electricity consumption end required power supply, now 1 road power supply and 2 road power supplys can be measured respectively and regulate to the current sampling circuit of SVC device,

When adjusting, as shown in Figure 3, need the cooperation of 1-4ZK change over switch in figure to realize:

Mono-section of bus operation of (one) No. 1 transformer belt 35kV, bis-sections of bus operations of No. 2 transformer belt 35kV, mother 100 disconnects (or No. 1 transformer be with mono-or two sections of buses operations of 35kV, 2# becomes power failure) simultaneously, and the handover operation in the feedback current loop of SVC device is sequentially:

(1) No. 1 transformer current circuit operation: the 1ZK switch that first closes, then pull open 2ZK switch;

(2) No. 2 transformer current circuit operation: 4ZK switch first closes; Pull open again 3ZK switch.

(2) No. 1 transformer has a power failure, and bis-sections of 2# main transformer band 35kV also move by 100 mono-section of mother band 35kV and SVC device, and the handover operation order in the feedback current loop of SVC device is:

(1) No. 1 transformer secondary current circuit operation: the 2ZK switch that first closes, then pull open 1ZK switch;

(2) No. 2 transformer secondary current circuit operations: 3ZK switch first closes; Pull open again 4ZK switch.

The wherein current sampling circuit of the secondary current of 1ZK:1 transformer current instrument transformer access SVC system; The short circuit point of the secondary winding of 2ZK:1 transformer current instrument transformer, prevents secondary winding in current transformer open circuit; The current sampling circuit of the secondary current access SVC system of 3ZK:2 transformer current instrument transformer; The short circuit point of 4ZK:2 transformer current instrument transformer secondary winding, prevents secondary winding in current transformer open circuit.

If use two-way with power source, can realize according to the setting of two-way power supply and regulative mode.

In addition to the implementation, the utility model can also have other execution modes.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection range of the utility model requirement.

Claims

1. the SVC feedback circuit for many power supplys, comprise at least two independent current sources, bus and SVC device, described independent current source and SVC device are connected on described bus, it is characterized in that: each independent current source is provided with a control cables that is connected to SVC device current sampling circuit.

2. the SVC feedback circuit for many power supplys according to claim 1, it is characterized in that: described independent current source comprises power supply, transformer and the incoming line cabinet that order is electrically connected, described incoming line cabinet is connected with bus by cable, and described SVC device current sampling circuit is connected into incoming line cabinet by control cables.

3. the SVC feedback circuit for many power supplys according to claim 2, is characterized in that: the bus between two adjacent described incoming line cabinets is provided with mother.

4. the SVC feedback circuit for many power supplys according to claim 1, is characterized in that: one group of conversion connecting valve and one group of shorting switch are all housed on every described control cables.

5. according to the SVC feedback circuit for many power supplys described in claim 1 or 2 or 4 arbitrary claims, it is characterized in that: described control cables is band screen cable.