Zhejiang Zhi Duoxin Electric Co., Ltd.

Overview

XBZ2 inteiligent/XBJ2 compact box-type substation of24kV (20kV) (hereinafter referred to as box-typesubstation) takes the advantages of foreign box-type substations, employs the new techniques, advanced electric parts and HV/LV automated technology, it meets the requirements of the state grid automation and electric power requirements. It is formed a box or several boxes that are assembled with HV switchgear, distribution transformer, LV switchgear, electric energy metering equ-ipment and power compensation equipment. The intelligent module is installed on its HV and LV side, to reach the requirements of automation in the distributiongrid and realize the remote control, remote sensing, remote signaling and remote regulating as well as upper co­ mputer system management.This equipment is applicable for the locations such as the urban high-rise buildings, residential houses, in dustrial and mining enterprises, municipal constructions, roads and street lamps as well as the temporary constructions.lt has many advantages such as the strong completeness, short installation period, small floor area, low investment, less main­ tenance, reliable operation, nice appearance, long service life, in addition, it is easy to harmonize with the surroundings.

Model and meaning

Use environmental conditions

Normal service conditions of outdoor box-type substation

a) The ambient temperature shall not exceed +40'C，and the average temperature within 24h shall not be more than +35°C . The min ambient temperature may be -10sheshidu5and -25°C. What;s more, the sharp change of temperature shall be taken into consideration.

b) The sunshine radiation of 1,000W/m2 (At noon onacloudless day) shall be taken into consideration.

c) The altitude shall not be higher than 1,000m.

d) If the ambient air is  subject to the pollution of dust, smoke, corrosive gas, steam or salt mist,

the pollution class shall not exceed the class III.

e) For class  1, the ice coating thickness  shall not exceed 1 mm; for class  10, it shall not be

thicker than 10mm; and for class 20; it shall not be more than 20mm.

f) The wind speed shall not exceed 34m/s.

g) The condensation and precipitation shall be taken into consideration.

h) The inductive electromagnetic disturbance voltage range shall not be more than 1,6kV in the secondary 

system.

Special service conditions

Ifbeyond  the  normal  service  conditions  mentioned  in  clause  3.1,  please  contact  and  negotiate with the manufacturer.

The main technical parameters

Rated voltage (Ur): On the HV side: 24kV On the LV side: 0.4kV Auxiliary circuit: AC110V, 220V and 380V; DC 24V

Rated capacity of transformer: 100,125,160, 200,250, 315,400,500, 630, 800, 1,000, 1,250, l,600kVA

Rated current (Ir): On the HV side: 400A and 630A On the LV side: Max 2,500A

Rated frequency (fr): 50Hz

Rated short-time withstand current (Ik): HV switchgear: 16kA 2s(4s), 20kA 2s(4s) LV switchgear: 15kA for 315~500kVA 30kAfor630~l,600kVA

Test time: Is

If the capacity of transformer is less than 315kVA,

the equipment will be exempted from the test. International protection of enclosure : Not lower than IP23D

Structural features

1. This design considers the territory, environment and variety of customer demands, it employs the modular structure combined with following types.

According to the HV switch connecting with the power grid: ring net type, terminal type, HV energy metering type, LV energy metering type.

According to the equipment arrangement: Chinese character” type structure and Chinese “ type structure.

According to the type of built-in transformer: oil- immersed full- seal transformer and dry- type transformer.

According to the type of HV switch: vacuum type load switch and combination unit switch gear, SF6 load switch and combination unit switch, gas-filled switchgear

According to the material of box body (enclosure): metallic enclosure and non- metallic enclosure

The metallic enclosure and frame are welded with the beam channel and steel 1 beam, the side wall and top cover is of two-layer assembly, the outer has the hoisting pin and mounting pin,  the metallic door has the good  earthing  line and  the under frame and  foundation  has the connecting  earthling  conductor.  There are doors installed  on  both  sides of transformer, which facilitate the installation and repair of the transformer; and safe and isolating net doors to prevent person entering into electrical isolating area by mistake and guarantee the safe ty of equipment and human.

2.  Good ventilation measures: the structure of box body is of two layers, the top of box is else made of heat - isolation material, which can lower the rise of indoor temperature caused by the sunshine and there is an automatic ventilator mounted at the side door of HV chamber, which can ensure transformer run safely in full load in the high temperature season.

3.  The HV switchgear on HV side provided with five-prevention measures and there is an energized reliable lock with the transformer compartment to ensure the human security. The international al protection of box body can reach 1P23D: It has good rain-proof performance.

4. Convenient operation and maintenance

There are some visible marks outside of the box type substation，indicating the HV compartment, through opening the compartment doors, they can be easily operated and repaired, each compartment has the automatic lighting device even the compartment of transformer is used for installing 9 maintaining and changing the transformer in addition LV compartm ent is of force connection and for repairing the channels.

5. Nice appearance and durability

The enclosure is made of AL-plates and color steel sandwich plates, it is given the pre- treatment and plating treatment，besides, it also can be non-metallic enclosure made of a glass fiber and  special cement and  with  the special technology  so  it has the obvious advantage like the strong  plasticity  of appearance,  corrosion  resistance,  heat isolation  and  sound  isolat ion etc. The surface coating is beautiful and durable, with high cohesion and soft color sense.

Type test

Three samples of XBZ2 intelligent/XBJ2 compact box-type substation of 24k V (20k V) have passed the type test conducted by National Center of Quality Supervision and Inspection for Electrical Control and Distribution Equipment, and they have met the requirements of relevant standards.

Key features and innovations

XBZ2 intelligent/XBJ2 compact box-type substation of 24kV(20kV) has the following innovative points and advantages: 1)There are intelligent modules installed at HV and LV circuits, they can pass the operation information and control signal to the upper machinevia the field bus or intelligent controller, to realize the remote control, remote sensing, remote signaling, remote regulating and system management. It covers the serious shortage of domestic similar products in the intelligent control. The wireless MODEM employs GPRS mode to connect with the user's mobile phone，so that user can monitor the opcrationsituation of box-type substation anywhere, anytime. 2) It uses the solid-encapsulated insulating switch, which has the features such as the high reliability, zero discharge, zero pollution, free maintenance, small volume and light weight, etc.，besides,  this switch is more environmental protection and safe. 3) The innovation point rests with that the Cu-Al composite bus is used as the carrying-currcnt conductor in the substation, which can lower the consumption of Chinese limited copper resource to the large extent. 4) It is designed with the assembled structure, with the features of strong completeness, high production efficiency, short installation period and low transportation cost. 5) It uses the nitrogen spring instead of the traditional windproof hook, can solve such problem that the traditional windproof hook easily comes off; and this spring is very nice and takes the convenience for the operation. 6) XBJ2 compact box-type substation of24KV, through the structure optimization of the high voltage components liketheHV load switch fuse, presents the perfect combination unit that is placed into  the oil tank of transformer and immersed in the oil. LV switchgear is minimized to reduce the volume of combined substation, so its floor space is only 1/3 〜1/5 that of usual products. The box body of transformer can disperse the heat naturally if it is exposed i n the air, therefore, it has the good operation conditions. What’s more, it possesses the outstanding advantages like the high mechanical strength, low loss, low noise, low temperature rise, strong overload capacity, etc., its structure presents the type of Chinese character “品”. 7) One invention patent and eight utility model patents have been applied for XBZ2 intelligent/XBJ2 compact box-type substation of24kV (20k) Vin many innovativepoints like the control principle, structure and new type of parts, etc., and they have been accepted.