HGIS/WEB Compact SF6 high voltage combined electric equipment

China Power (Beijing) High Voltage Electric Equipment Co., Ltd.

Overview
Brief introduction

　　HGIS is a new type of high voltage electric equipment. Based on such advantages of GIS (gas insulated switchgear) as compact structure, high reliability, and little maintenance, HGIS adopts the bus-bars for conventional AIS (air insulated switchgear) that enjoy an extremely low failure rate. At the same time, HGIS resolves in a good way the disadvantages of conventional AIS such as large floor space, low reliability, and much maintenance.

　　By cooperating with a famous high voltage switchgear manufacturer from Russia and using the advanced Russian technologies, our company developed 145 kV WEB series HGIS products.

Advantages of the equipment
　　The space used and the floor area are small.
　　Flexible combination, highly reliable and visual operation, and little maintenance (basically maintenance-free for 25 years)
　　The equipment can be installed directly outdoors, so the amount of civil work and that of electric installation work are extremely small. The installation is simple.
　　The amount of SF6 gas used is small (only 20% of the amount of SF6 gas used for GIS), which satisfies the requirements for environmental protection.
　　According to the comprehensive comparison, the investment in HGIS is low.
　　Small volume, light weight (silicon rubber bushings and aluminum tanks), strong resistance to pollution, excellent hydrophobic nature, and good earthquake resistance.
　　Because its installation time is short and the times of power outage needed during its installation are few, HGIS are more suitable for the extension or transformation of power plants and substations.

Scope of application

　　According to the design proposals with different layouts of power plants and substations, there are several types such as SBB (single bus-bar) type and DBB (double bus-bar) type for 145 kV applications to meet the demands of different customers.

Brief description of the structure
　　Circuit breaker and its operating mechanism
　　The circuit breaker is equipped with self-energy arc extinguishing chambers. Part of the energy needed for breaking the current comes from the arc itself. Therefore, the energy needing to be provided by the operating mechanisms is reduced. The operating mechanisms are spring operating mechanisms imported from abroad.

Internal structure of the circuit breaker 　　　　Operating mechanism

Combined disconnecting switch/earthing switch and operating mechanism
　　 Three-phase ganged operation. Based on the rotary motion of the moving contacts, the combined disconnecting switch/earthing switch completes closing and opening operations when the operating conditions are satisfied. The operating mechanism is imported from abroad.

　　　　　　

“On” position 　　　　　　　　“Transition” position 　　　　　　　“Earthed” position

 

Operating mechanism

 

　　　　　　　　　　　　　　　　　　　　　　　　　　

Current transformers
　　Traditional epoxy resin cast current transformers are used, and digital photo-electric current transformers can be used, too.

　　　　

Epoxy resin cast CT　　　　　　　　　　 Photo-electric CT

Electronic PTs and CTs

　　　　　　　　　　　

OET711CT—HGIS CT 　　　　　　OET711VT—HGIS PT

　

Bushings

　　The equipment is connected to the overhead line bus-bars through SF6 gas insulating bushings. Silicon rubber bushings and high strength porcelain bushings can be used according to the users’ requirements.

Supports

　　After hot galvanization and painting, the supports are resistant to corrosion. They are designed to provide maximum bearing force and robustness, so the requirements for civil work are minimized.

HGIS technical parameters

 

　　Notes: * These can be done according to the requirements of the user.
　　　　　 ** When the equipment operates in a region at -40℃, measures need to be taken to prevent SF6 gas from being liquefied.


Outline dimensional drawing

　　　　　Legend
　　　　　A: Composite bushing
　　　　　B: Disconnecting switch189L
　　　　　C: Circuit breaker 152
　　　　　D: Disconnecting switch 189
　　　　　E: Earthing switch
　　　　　F: Bushing-type CT

Foundationdrawing

　　　　　Control cabinet side
　　　　　Cable trench
　　　　　Outdoor ground
　　　　　Cable trench
　　　　　Axis
　　　　　YQ-axis
　　　　　XQ-axis

　　Technical requirements
　　1. Anchor bolts are manufactured with steel No. Q235-A. The chamfer angles on the end close to threads are 2×45. The surface roughness concentration of threads is Ra6.3, and that of other parts is Ra25. All the components need hot galvanization, and the thickness of the zinc coat should be larger than 85. The requirements for dimensional accuracy are all based on the components that have been galvanized.
　　2. The length of the exposed parts of the embedded M 20 anchor bolts should be 75 mm, and the dimensional error of anchor bolts should be 1 mm. The horizontal deviation of the head faces and the deviations of the left and right sides of two foundations should not be larger than 1 mm.
　　3. The foundation drawings are only for design reference. The construction drawings must be designed according to the local geological conditions and the electrical requirements.

　　Three nuts and double flat washer
　　Anchor bolt drawings
　　Vertical loads transferred to the foundation through the support

　　Dynamic loads
　　Along the XQ-axis
　　Static loads
　　Vertical

Intelligentized modules
　　On the basis of international advanced technologies, our company has developed the intelligentized control system for compact SF6 combined switchgear.

Circuit breakers and operating mechanisms
　　The intelligentized control system for compact SF6 combined switchgear has two functions: local control and measurement & control. Through the measurement & control unit, the system gives control commands, which are executed by the local control unit. The cabinets of the system are made of 2.5-mm high-quality stainless steel plats. Each of them is of the double-layer structure, with the outer layer being the ventilation layer. The cabinet’s surfaces is of the fully-enclosed structure, able to prevent damp and dust effectively. The circuit boards inside the cabinet have undergone “three-prevention” treatment. There is a constant-pressure breathing system inside the fully-enclosed structure. The system has heat radiating and heating functions so as to adapt to the changes in seasons and regions.

Intelligentized measurement and control cabinet

　　

Functions
　　Monitoring functions
　　Operating current of the opening and closing coils for operating mechanisms
　　Operating voltage of the opening and closing coils for operating mechanisms
　　Detection of the status of the opening and closing circuits
　　SF6 gas density
　　Positions of the contacts of circuit breakers and combined disconnecting switches + earthing switches
　　Operating mechanisms (including circuit breakers and combined disconnecting switches + earthing switches)
　　Local control cabinet monitoring

Human-machine dialogue functions
　　The communication unit module of HGIS has a RS232 serial port. When local control is being performed and various operational parameters are being set, a portable device or a supporting displaying panel is connected with the serial port to realize human-machine dialogue. The main functions are as follows:
　　Setting of various communication parameters
　　Display of various memory unit values
　　Communication supervision

Communication functions
　　Optical fiber Ethernet controllers with double backup redundancy are installed to realize the communication with the monitoring system of the substation at a higher level.

Relay protection functions
　　Protection for various types of high voltage lines
　　Protection for main high voltage equipment

Instructions to ordering
When placing an order, you are asked to provide the following information:
　　Design specification
　　Main wiring scheme diagram and layout diagram
　　Area of the primary equipment for the substation
　　Number of coils, capacity, transformation ratio, and accuracy class of each current transformer
　　Names and quantities of the spare parts and accessories needing to be ordered