6.12 HT-7U 110KV Power Transmission and Transformation System
Ⅰ. Design Concept
The HT-7U superconducting tokamak device is a major scientific engineering project of the 9 th national five years plan. The 110 KV power transmission and transformation system is the power supply center of the HT-7U device and the important equipments for its power supply insurance. It supplies different power supplies to the device for providing reliable technical supports of realization energy transport, power conversion and operational control.
According to the technical requirements and characteristics of the different power supply systems of the HT-7U superconducting tokamak device and the concrete situation of the geographical location and the basement foundation, the 110 KV power transmission line is a double circuit over head transmission line, the transfomer substation is outdoor type, the 110 KV transformation and distribution facilities are outdoor units, the 10 KV and lower transformation and distribution facilities are indoor units, and the control and protecton devices are microcomputer combination automatic controller.
The input and output voltage of the system are 110 KV and 10 KV respectively. The total capacity of the substation is 81.5 MVA. Two transformers with the same connection type and short circuit impedance but different in power capacity are chosen, According to the load situations, they can be connected in parallel and operated in sesveral modes.
Ⅱ. Design Layout
The general input point of the 110 KV power transmission line is taken from the bus isolation room of the 110 KV power supply network of the Hefei Power Station. The current passes through a double circuit transmission line put on the same stalk, enters the 110 KV transformer substation inside the area of the Institute of Plasma Physics. After that, the voltage is reduced to 10KV and the power is distributed to the different 10 KV switch yards.
The total power capacity of the system is 81.5 MVA, one set of 31.5 MVA and another set of 50 MVA. The power is supplied by a double circuit line. The inner bridge connection is accepted, which can be operated in parallel or the 10 KV bus 1 and 10 KV bus 2 are operated separately to supply power to each yard. The SF6 circuit breakers are chosen for 110 KV switches. The high voltage distribution panels equipped with VSI type high voltge vacuum breakers are chosen for 10 KV system. The combination automatic controllers equipped with microcomputer are used for all control, protection , remote communication , remote measurement, inspection and registration. The simulation operating device equipped with five preventing lock is installed.
Ⅲ. Design Parameters
- Short circuit capacity of the system Sd 1064 MVA
- Over head line
type of conductor aluminum wire with iron core LGJ-240
3. Coupling condenser
type OWF-100/3-0.0066
4. Coupling filter
type JL-400-T
5. Grounding switch
type JD-2
6. High frequency intercepter
type XZK-800/20-N3.Y
7. Zinc oxide arrester
type YSW1-100/260
8. Single phase PT
type JDCF-100W2 100/3/0.1/3/0.1
9. Isolating switch
type GW5-100D/630 A 20 KA/50 KA
10. Current transformer
type LB6-100 W2 2×300/5 0.5/P/P/P
11. SF6 circuit breaker
type LW25-126/2000A 20KA/50KA
12. Main transformer No.1
type SZ10-Z-31500/110
31.5 MVA
110 KV/10 KV
110±8×1.25%/10.5
YN,d11
U k %=10.5
LRD transformer center bushing CT 150/5 0.5/10P
13. Main transformer No. 2
type SZ10-Z-50000/110
50 MVA
110 KV/10 KV
110±8×1.25%/10.5
YN,d11
Uk%=10.5
LRD transformer center bushing CT 150/5 0.5/10P
Ⅳ. Connection Circuit of the Power Transmission and Transformation System [wangsh1]
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