40.5kV GIS Intelligent Gas Insulated Metal-enclosed Switchgear

Ⅰ Overview:

According to the needs of product development and technological progress, we developed a new product of Z F63-40.5(L) type G IS, which is a compressor-type arc extinguishing principle with a full spring mechanism. It can realize the transformation of the old station without changing the foundation of the switchgear, and at the same time meet the new construction needs of the typical layout of 40.5kV GIS, which is suitable for indoor and outdoor use.

Ⅱ Main Technical Parameters:

Ⅲ Main Features and Advantages

Small unit size, light weight, excellent seismic performance:

This series of GIS products is the smaller GIS spacing unit of the same kind, with a standard spacing width of only 0.8m; the product has a small volume and compact structure, which is smaller than the size and weight of KYN61.As the shell and conductor are made of aluminium alloy, they are corrosion-resistant and light in weight.

Reliable electrical conductivity:

Highly reliable electrical contact structure, so that the conductor in the larger contact area can maintain a stable contact pressure. The conductor adopts silver plating process, the hardness of the plating layer can reach HV120, strong adhesion, from the structural design to ensure that there is a minimum contact resistance.

High reliability:

The insulation structure of the product is reasonably designed, and the insulating parts used have undergone strict quality inspection, and the overall withstand voltage level exceeds the requirements of the national standard (GB) and the power industry standard (DL). The use of basin insulators with metal outer ring eliminates the stress on the basin insulators during assembly; increases the reliability of the shell connection grounding and improves the ability to resist external interference.

Excellent SF6 gas system and sealing technology:

The SF6 gas system adopts a decentralized monitoring method, using pressure gauges and density relays as one SF6 gas monitoring element, and each gas chamber is equipped with a multifunctional shut-off valve, which facilitates the on-line calibration of SF6 thermometers. The use of mature sealing technology, sealing materials, the addition of double sealing structure ensures that the product has a lower SF6 leakage rate.

5. Strong breaking capacity:

The circuit breaker adopts the principle of self-energetic arc extinguishing, which has strong short-circuit opening and closing capacity, and its electric life is up to 23 times. The disconnecting switch can meet the requirements of bus-bar conversion current and bus-bar charging current; the quick-earthing switch can meet the requirements of closing short-circuit current and inductive current.

6,Intelligent requirements:

According to the special requirements of customers, we can add electronic current transformers, electronic voltage transformers or electronic current and voltage transformers combined as a whole, signal collectors, merger units, and intelligent component cabinets that can realize the functions of one-key control and on-line monitoring to realize the digitalisation and intelligence of the products and make the substation unattended.

Ⅳ Structure and Working:

General of the main structure:

The GIS is featured by three-pole-in-one enclosure (except incoming line bushing and and

outgoing line bushing). The main components include the Circuit Breaker(CB), three-position

Dis-connector/ Earthing Switch(DES), Fault-making Earthing Switch, Current Transformer(CT), Voltage Transformer(VT), Lightning Arrestor(LA), incoming/outgoing components( Gas-Air

Bushing(BSG), Cable Sealing End(CSE), Oil-Gas Bushing (Oil-Gas BSG), Bus-bar (BUS)(includes main Bus-bar and branch bus-bar), Local Control Panel (LCP), etc. All bays can be arranged with the standard components. In power circuit, the conductors for CB are arranged in shape of "straight line", the conductors of other components are arranged in the shape of "regular triangle" in the enclosure. Spring contact is used between conductors for tran-sitting connection.

Structure of Main Components:

Circuit breaker (CB):

The circuit breaker adopts the compact three-phase common box overall scheme, and the three-phase conductors are arranged in coplane.

The circuit breaker adopts the principle of pressurized gas extinguishing and is equipped with CT20 spring operating mechanism. Three-pole mechanical linkage, strong breaking ability, full capacity of breaking up to 23 times.

On the one hand, the SF6 gas in the pressure cylinder is compressed through the opening movement of the pressure cylinder, on the other hand, the arc energy is used to increase the pressure of SF6 gas in the pressure cylinder. During the opening of the circuit breaker, the high-pressure SF6 gas is centrally blown through the nozzle to the arc generated between the static and static arc contacts, so that the arc can be effectively cooled and extinguished.

Closing operation:

Driven by the operating mechanism, when the insulation rod moves to the right, the piston rod, pressure cylinder, active contact, moving arc contact and nozzle connected with it move to the right, the moving arc contact and the active contact contact respectively in the static arc contact and the main static contact and reach the closing position.

Breaking operation:

Driven by the operating mechanism, when the insulation rod moves to the left, it drives the pressure cylinder and other parts to move to the left to compress SF6 gas. In addition, after the arc is generated, the nozzle throat will be blocked, and the energy of the arc heats SF6 gas to increase its pressure; In this way, high temperature and high pressure SF6 gas is blown to the downstream area through the nozzle throat, and the arc is cooled, and the arc is extinguished when the current passes zero. Thereafter, as long as the insulation recovery strength between the fractures is greater than the voltage recovery strength, the current is successfully broken.

DS-ES:

Isolation one ground three station switch is a three-pole common box structure. The so-called three-station, through the three-station mechanism to drive the movement of the middle contact, can respectively achieve isolation, grounding, isolation and grounding of three electrical states. The ground switch in the three-station switch is used as a ground switch for maintenance and is a ground switch for safety protection during maintenance.

The insulating tie rod engages with the rack of the middle contact through the gear, and the positive and reverse rotation of the insulating tie rod drives the middle contact to the isolated and grounded state respectively.

The three poles of the isolated ground three-station switch are equipped with a three-position electric operating mechanism, and the three poles are connected by an insulating tie rod. The mechanism is composed of a motor, a transmission mechanism, a micro-switch, an auxiliary switch, etc. The mechanism motor drives the worm and the fork to rotate, so that the three-station switch realizes the opening and closing operation through the gear groove transmission system.

Smart GIS solutionsL

General of Solutions:

According to the requirements of the State Grid's "Intelligent Technical Guidelines for High Voltage Equipment", we set up intelligent components according to the circuit breaker intervals, with one intelligent component for each interval, and the intelligent component cabinet and the convergence control cabinet are merged into a unified intelligent component cabinet. According to the requirements, we have installed condition monitoring IEDs in the intelligent component cabinets and integrated intelligent terminals and merging units. The intelligent terminals perform the operation control of all circuit breakers and disconnecting switches in the intervals as well as the collection of switching status information. The intelligent terminal performs the operation control of all circuit breakers and disconnectors in the interval and the collection of switching status information, while the merging unit collects the current and voltage information from the electronic current and voltage transformers in the interval. Currently, the intelligent switch-gear consists of circuit breakers, disconnecting switch bodies and intelligent components.

Configuration and Networking Solutions for Smart Equipment of GIS:

Schematic of Smart Component of GIS Equipment

The above networking method has the following features:

(1) The firewall function of data-gram filtering is realized on the monitoring function IED through software measures.

(2) Each interval corresponds to a monitoring function IED, which reports equipment information to the station control layer through the MMS network and is co-networked with the control and protection MMS.

(3) The condition monitoring IED obtains various curve data, modelled by IEC61850, defines the relevant logical nodes and variables, and exchanges data with the station control layer through the dedicated optical fibre Ethernet interface. The condition monitoring IED collects the data and judgement results and performs a comprehensive analysis according to the relevant criteria to obtain the final analysis results. The data is exchanged with the station control layer via a dedicated MMS fibre-optic Ethernet interface. The condition monitoring IED provides services to the station control layer server in the mode of IEC61850 MMS server, which ensures that the station monitoring server can collect the data and judgement results of each master controller for the convenience of the station management personnel to view.

(4) The station is equipped with a GPS timing device, which can be used to synchronize with the intelligent terminal and the merging unit through the RS-485 differential B-code signal.

(5) The process layer GOOSE and SMV are separately networked, and the intelligent terminal and merging unit adopt the tripping method of direct picking and jumping between them and the protection.

Ⅴ Typical Bay Arrangement:

Ⅵ Typical General Arrangement of GIS:

The primary primary connection of GIS can use the principle of "building

blocks" to meet different wiring styles according to customer needs. For the example as below: