SF6 GAS INSULATED METAL ENCLOSED SWITCHGEAR (GIS)

SF6 GAS INSULATED METAL ENCLOSED SWITCHGEAR (GIS)

About company The «Elektroapparat» plant starts its operation in 1922 as a plant manufacturing high-voltage electrical equipment. During the first two years of its existence the Plant was producing oil-filed circuit breakers, indoor and out door switches, current transformers, and other equipment for currents in the range of 3 to 35 kv. By 1928, the company had produced more than 100 types of equipment up to voltage 120 kv. The 1950-ies saw the production of shunting devices, measuring transformers and 800 kv circuit breakers. GIS developing department was organized in 1976. First 110-220 kv GIS appeared in 1979. In 1982, the first deliveries of GIS were made on energy facilities of the USSR. Futher development of the plant in the 80-ies was connected with the beginning of production of generator sets 15,75-24 kv and 110-1150 kv SF6 switchgears and current transformers.

SF6 GAS INSULATED METAL ENCLOSED SWITCHGEAR (GIS) «Elektroapparat» is one of the oldest companies in the world that continues to move forward... Elektroapparat GIS provide maximum reliability The JGT-145 includes the main technological equipment of substation such as disconnectors, earthing switchs, circuit breakers, current and voltage transformers, surge arresters, combined in a grounded metal enclosure filled with SF6. Reliability The main sections of the switchgear enclosed in a metallic sheath, so the device is not susceptible to contamination from the environment, climate and aging insulators over time. JGT-145 passed the whole test cycle to confirm their reliability and uptime. Efficiency JGT-145 meets all the requirements, which are critical to modern high-voltage equipment for power and reliability. All keys components are easily accessible and simplify activities such as gas handling, meter reading of gas density, or the initiation of manual operation. Convenience Delivery of fully assembled at the plant cells, greatly reduces the effort required for on-site installation, only need to connect flanges modules. After that, the Client is required only run a cable or air connection to the cell. Thus, GIS can be easily installed without significant outages. Safety Due to the extremely low level of noise and electromagnetic radiation, it can be installed in close proximity to areas sensitive to electromagnetic radiation, residential areas, as well as intraurban areas. This type of GIS is an environmentally friendly high-voltage switchgear. All details of the switchgear under voltage, enclosed in a grounded enclosure, providing enhanced security personnel. GIS of company «Electroapparat» became synonymous with reliability and trust of customers around the world

Introduction The present technical manual is applied to a JGT-145 type three-pole SF6 bay (hereinafter, «bay») and intended for acquaintance with technical characteristics, design of a bay, and also design and principle of operation of assembly units included in a bay structure, and contains the information necessary at assembly, transportation and storage of a bay. Function The bay is intended for operation in GIS on reception and distribution of an electrical energy in three-phase a.c. networks of frequency 50 Hz with an earthing neutral (earth-fault factor 1,4) of rated voltage 132 kv in normal and emergency conditions (performing of switching operations, measurements and protection). The bay is intended for operation in the following environmental conditions: - in macroclimate areas with moderate or cold climate - for indoor operation in heated or cooled and ventilated premises (without air conditioning); - working values of air temperature during operation: upper value - plus 40 ºС; lower value - plus -30 ºС; - altitude above sea level - no more than 1000 m; - operating position of the bays on a horizontal plane; Name of parameter Norm Rated voltage, kv 132 Maximum operating voltage, kv 145 Rated frequency, Hz 50 Rated current, А: busbars taps 3150 2500 Peak withstand current, ka 100 Rms value of short-time withstand current, ka 40 Short-time withstand current, ka 40 Current duration (short circuit time), s 3 SF6 leakage per year, % of SF6 mass, no more 0.5 Height, mm 2450 Width (with a pass / step), mm 1600 Depth (length), mm 3450 First major inspection, years 25 Expected lifetime, years 50 Ambient temperature range, ºС -30 to +40 Earthquake resistance, MSK 9 Mass, kg 3600

Bay design The bay consists of three identical poles, busbar sections, drive of the circuit breaker, drives of disconnectors (one per three poles) and earthing switches (one per three poles) and hardware cabinet. The pole of a bay consists of assembly units: the circuit breaker with a current transformers, bushing unit, bus disconnectors unit, and cable connection unit. Due to a modular construction of the GIS we can produced all GIS upon customer requests. All inner mechanisms and current-carrying parts of the bay elements are enclosed in grounding gas-tight aluminium enclosures. Epoxy insulators are installed between enclosures to separate the volumes. The insulators are used for supporting current-carrying parts of the bay and provide an insulation of alive parts from the grounded enclosures. For convenience of operation and disassembly in service the pole of a bay is separated by the hermetic insulators on 4 sealed, isolated from each other spaces: the circuit breaker with a current transformer, bushing unit, bus disconnectors unit and busbars. The hermetic insulator is installed between an enclosure of a current transformer and an enclosure of a bushing unit and separates these two spaces with different pressure, the second hermetic insulator is installed between an enclosure of the circuit breaker and the bus disconnector unit, separating also the spaces with two different pressures, and the third hermetic insulator is installed between an enclosure of the bus disconnector unit and expansion bellows and separates the spaces with an identical pressure. The separation of spaces of bus disconnectors and busbars is necessary owing to the service conditions for a possibility of disassembly of one of buses, without pressure release of the other. The SF6 in the components of a bay is a main insulating and heat removal element, and in the circuit breaker, moreover - an arc-extinguishing one. Each volume is supplied with valves and gas density monitors with temperature compensation, for pressure control. The availability of valves allows to fill in and to bleed the hermetic spaces separately from each other. All isolated spaces are supplied with the safety rupture disc for protection against pressure increase in an enclosure in case of an internal flashover. The grounding system of a bay, built-in in GIS, is designed so, that the elements of a grounding system are located in a bay and are connected with a grounding mat of GIS. For ensuring of the grounding all enclosures of the bay components are electrically connected among themselves (by the fit of flanges of adjacent components «metal-to-metal» and mounting of buses shunting the bellows compensators) and grounded.

General view 1. Disconnector drive 2. Disconnector/earthing bay 3. Earthing drive 4. Current transformer 5. Gas density monitor 6. Three-phase busbar 7. Circuit-breaker drive 8. Supporting metal 9. Circuit-breaker bay 10. Three-phase busbar

GIS bays Circuit-breaker Circuit-breakers of Elektroapparat with auto-puffer interrupters have a simple principle of arc extinction and simple design. The energy required for interrupting short circuit currents is partly taken from the arc itself, significantly reducing the energy required from the operating mechanism. Lower operating energy inherently reduces mechanical stresses, on the circuit breaker itself as well as on the foundation, and increases circuit breaker reliability. Current transformer The ring core current transformers concentrically enclose the primary conductor. The core support is provided by the pressure-proof enclosure, which is insulated from the basic flange to prevent the return current from passing through the cores. Voltage transformer The Voltage transformers are based on the electro-magnetic transformer principle, where primary and secondary wibdings are galvanically separeted from one another. The singlepole inductive voltage transformers are connected to the switchgear with a standardised connecting flanfe and a partition insulator. Main features of voltage transformer are high secondary output and accuracy, no ferroresonance possible in absence of circuit-breaker grading capacitors. Disconnectors and earthings Disconnectors mute the individual sections of the electrical circuit, after loading on this section turned off by the circuit-breaker. The three position disconnector and earthing switch uses casted aluminium shell structure which is less weight, smaller size and can be operated electrically or manually. The fast-acting earthing switch The fast-acting earthing switch is used to earth insulated sections of the installation to protect personnel during overhaul and assembly work. But it s also employed for earthing capacitance (cables, transmission lines, etc.). The earthing switch can be mounted at any position by using a linear connection element, thus ensuring the greatest flexibility in switchgear layout.

Important issues Transportation GIS JGT-145 is optimized for transport and on-site installation. Thanks to their outstanding compactness, even larger units for high voltage levels are still easy to handle. Most switchgear can be shipped as completely assembled and tested bays pre-filled with SF6 gas. JGT-145t types are even shipped in standard containers. Up to three single switchgear bays, completely assembled and tested, come as a single transport unit. All goods are packed according to their specific transport conditions and in line with conditions and duration of temporary storage. Installation and commissioning The well-thought-out transport optimization significantly reduces the effort required for installation on-site and allows easy and rapid installation of the switchgear with relatively few special tools. After assembly, the entire switchgear is tested to ensure proper electrical and mechanical function. All tests are performed in conformity with IEC and all other relevant standards, and the results are documented in the final test reports. High degree of adaptability To meet individual requirements, JGT-145 can also be equipped with any other commonly available bay and substation control and protection system as well as with proprietary systems. Standard switchgear control interfaces enable the connection to any analog or digital control, protection, and monitoring system. Additional sensors and interfaces for a wide range of diagnostic and condition monitoring systems and purposes are available on request.

For more information, please contact our Customer Support Center. Tel: (812) 677-83-97 (812) 677-83-93 Fax: (812) 677-83-90 OJSC HV «Elektroapparat» Manufacturer HV equipment 199106, Russian Federation, St. Petersburg, 24th linija of VO, 3-7 Tel: (812) 677-83-83 Fax: (812) 677-83-84 E-mail: box@ea.spb.ru Web:ea.spb.ru Subject to change without prior notice. The information in this document contains general descriptions of the technical options available, which may not apply in all cases. The required technical options should therefore be specified in the contract.