The Development of ±800kV/4750A UHVDC Valve & HVDC/FACTS Status in China For EPRI HVDC & FACTS Conference Aug. 30, 2011 Palo Alto, California, USA
Quick Facts SGCC: Ranked the 8th in the 2010 Fortune Global 500 with US$237.3 billions revenue, 1.5 millions employees total CEPRI: Subsidiary of SGCC, 7,000 employees, 9 Labs, 11 R&D divisions, 12 manufacturing facilities CET: Subsidiary of SGCC, 20,000 employees, EPC and T&D manufacturing including two publicly listed companies
The Development of ±800kV/4750A UHVDC Valve for Jingping-Sunan UHVDC Project World s longest and largest HVDC Project
Jingping-Sunan UHVDC Project World s longest and largest HVDC Project The sending end Yulong converter station is located in Anning valley in the southwest of Xichang City, Sichuan province. The receiving converter station is located in the Tongli area in the south of Jiangsu province. The rated transmission capacity is 7,200 MW. The transmission distance is about 2,093.5 km. The rated DC voltage is ±800 kv, the rated current is 4,500 A. Scheduled Bi-polar service :by end of 2012 by bipolar. In Mar. 2011,CEPRI was awarded with the contract for converter valve of Jingping-sunan 800kV project. 4
A5000 Type UHVDC Valve of CEPRI CEPRI have developed its own UHVDC valves and finished type test in July, 2010 Satisfy ±800kV/4750A UHVDC project 9 levels in one Thyristor Clamp Assembly(TCA) Union design concept of water resistors Separate design concept of reactors Series-parallel connection cooling pipework 5
Structure & Feature of UHVDC Valve The Layout and Operation Mode of UHVDC Valve The 800 kv DC voltage is built up by two 400kV in series.(i.e. 400+400). The DC voltage of each 12-pulse bridge is rated at 400 kv. In case of fault in one of the 12-pulse bridges, the others will continue to run. Typical system diagram of the ± 800 kv HVDC transmission 6
Structure & Feature of UHVDC Valve The Layout and Operation Mode of UHVDC Valve De-icing mode The two 12-pulse bridges can switch into parallel working mode to double the rated DC current, so as to melt the ice. +400kV Neutral Operation schematics of converter station ice-melting 7
Structure & Feature of UHVDC Valve The Valve Hall and Valve Tower Structure Each12-pulse converter bridge is installed in a separate valve hall. 12-pulse converter bridge for 0 ~ 400 kv is installed in the low voltage, while 400 ~ 800 kv in high voltage hall. Valve tower is hang by suspension insulators at the top of the valve hall, meeting high potential of air clearance and creepage distance requirements. Valve hall layout for pole 1 3D diagram of double valve tower 8
Structure & Feature of UHVDC Valve The Technical Features of A5000 Valve 9 thyristor levels in a TCA. Configured to be 8.5 kv/5000a 6-inch thyristors, and compatible with 5-inch thyristors. A flexible tower structure with suspended seismic design. Series-parallel cooling loop. Dual energy storage of high-capacity is used in the thyristor trigger system, to improve the system operational capabilities. Technical parameters of A5000 valve for Yulong Station Pulses 12 Number of bridges for each side 4 12 pulses Suspension or support Suspension Number of double valves in a complete single-pole 12 Number of modules in series in a single valve 4 Number of thyristor in a single valve 70 Number of redundant thyristor in a single valve 3 Number of reactor in a single valve 16 9
Design of UHVDC Valve The basic functional unit of the A5000 valve is the valve section, each composed of nine 7.2kV thyristors or eight 8.5kV thyristors in series with two saturable reactors. The electrical schematic diagram of the valve section of A5000 valve The frame of the valve model is composed of a supporting structure including the EPGC trough side beam and five aluminum trough beams dv/dt Reactor TTM box DC Resistor Damping Resistor Damping Capacitor Thyristor Cooling Pipe The three dimension diagram of the valve model of A5000 valve 10
Design of UHVDC Valve Key components of the valve 6-inch Thyristor Maximum non-repetitive off-state voltage is 8.5 kv. Maximum on-state current is 5000 A. Saturable Reactor High inductance at low current (<100A) Moderate inductance in fully-saturated state (5-10H) Progressive saturation characteristic Well controlled damping Low conduction & hysteresis losses Low step current at turn-on Control di/dt and peak current at turn-on Limit dv/dt in off-state Assist with voltage sharing under fast transient conditions 11
Design of UHVDC Valve The development of the key parts of the valve The damping circuit Damping resistor : direct water cooling resistor, 40 Ω & 2700W. Damping capacitor: air-insulated and the solid resin-insulated, one 2- terminal capacitor C1 & one 3-terminal capacitor C3, equivalent damping resistor is 1.5μF. DC grading resistor: two thick-film resistive elements on the thyristor heatsink, the value is 36*2 kω. C3 C1 7.5uF 7.5uF 7.5uF 7.5uF 7.5uF C2 0.5uF Rj1 Rj2 C 1 C2 Rx T C3 Rd TTM TTM Energystorage Circuit 12
Design of UHVDC Valve The development of the key valve parts The triggering and monitoring system: VBE Work mode set by the Control & Protection. Trigger & monitor the valve. Comprehensive self-test function. Detects the status of itself or valve and sends the information to the SCADA system through the profibus. Detects the leak condition of the valve, and sends the information to the SCADA. Detects the counter of the valve arrester and sends the numbers of the operations of the valve arrester to the SCADA. 13
Design of UHVDC Valve The development of the key valve parts The triggering and monitoring system: TTM Trigger the thyristor by on VBE commands; monitor the status of the thyristor in real-time and sends those to VBE. Provide Forward overvoltage protection & dv/dt protection for the thyristor; trigger the thyristor when the voltage & dv/dt exceeds the set level. Decrease the protection level automatically after the 6 loops of continuous operation of the forward overvoltage protection. Trigger thyristor when the forward voltage across the thyristor in its reverse direction recovery period exceeds the set level. Trigger thyristor in case the current intermittent happens when thyristor is on. C1 Rj1 T1 C2 C3 TTM Power Monitor Forward Overvoltage & dv/dt Protection Reverse direction recovery protection Rd TTM Power Rx Rj2 Thyrisor Voltage Measure Forward Voltage Monitor optical/electric transformation Central Processing Unit Trigger Amplifier1 Trigger Amplifier2 electric /Optical transformation To GU Trigger optical fiber Return optical fiber 14
Type test of the A5000 type valve Operational type test of the valve To verify the design of the A5000 type valve with regard to its performance under normal operating conditions and overload conditions, abnormal operating conditions and transient fault conditions according to IEC Publication 60700-1. Synthetic Test ( Operational type test) for A5000 thyristor valve 15
Type Test of the A5000 Valve Dielectric type test of the valve A5000 Valves Dielectric Type Test Items Serial Test Items Test Items Parameters 1 Valve Support Structure DC Voltage Test 1213 kv±3%/910 kv±3% 2 Valve Support Structure Valve Support Structure switching Impulse Voltage 1400 kv±3% Tests Test 3 Valve Support Structure Lighting Impulse Voltage Test 1650 kv±3% 4 MVU DC Voltage Test 1485 kv±3%/1125 kv±3% MVU(Multiple Valve Unit) 5 MVU switching Impulse Voltage Test 1700 kv±3% Test 6 MVU lighting Impulse Voltage Test 1900 kv±3% 7 Valve DC Voltage Test 330 kv±3%/165 kv±3% 8 Valve AC Voltage Test 310 kv±3%/200kv±3% 9 Valve switching Impulse Voltage Test 456 kv±3% 10 Single Valve Test Valve lighting Impulse Voltage Test 456 kv±3% 11 Valve steep-front Impulse Voltage Test 477kV±3% 12 Valve Non-periodic Firing Voltage Test (contains EMC test) 395 kv±3%/7ka±3% 16
Type Test of the A5000 Valve Operational type test of the valve A5000 Valves Operation Type Test Items Serial Test Items Test Items Parameters 1 Maximum Firing And Recovery Voltage Test 20.7 kv/5000 A 2 Maximum Temporary Operating Duty Test(2s) 47.6 kv/3200 A 3 4 Periodic Firing and Extinction Type Tests Maximum Temporary Operating Duty Test(10s) Minimum Delay Angle Test 33.8 kv/3200 A 2.3 kv/5000 A 5 Minimum Extinction Angle Test 7.2 kv/5000 A 6 Temporary Under voltage Test 0.75 kv/1350 A 7 Intermittent Direct Current Test 33.8 kv/100 A 8 Fault Current Single Loop Test 50 ka/36.5 kv 9 Test Multi-Loop Test 50 ka/18.7 kv 10 Forward Recovery Protection Test (100 μs\10 μs\1.2 μs) 7.2 kv/5000 A 17
HVDC in China About 25 HVDC projects in total, up to 1100kV HVDC Average New HVDC Construction Time: 2 years ( including substation and line ) China became self-sufficient in HVDC design, manufacturing and construction in 2005.
Energy Sources in China China s power grid construction and operation must satisfy large range and the optimum distribution of resources over long distance, can be achieved through constructing power highway. UHVDC is one of the key technologies to meet these requirements. Northeast China Xinjiang North China Tibet Coal power base is located in Northern China Hydroelectric is located in Southwestern China Load center is located in Eastern China The uneven distribution of energy resources over load centers is becoming an increasingly prominent issue Northwest Hydroelectric Power of Chinsha River 川渝 South China Load Centre 上海 East China Central China Taiwan Energy distribution and configuration diagram 20
China 2020 HVDC Vision
UHVDC in China By the end of 2010, two UHVDC, ± 800kV/3000A Yunnan-Guangdong Project and±800 kv/4000a Xiangjiaba-Shanghai Project had been built and put into operation. Between 2011 and 2012, another two ±800 kv UHVDC projects, Xiluodu-Zhexi and Hami- Zhengzhou Projects, and one ±1100 kv/5000 A Zhundong-Chongqi UHVDC Project will also start. ±800 kv/4500a Jinping-Sunan Project was also commenced in 2010. In the next 5 years, SGCC plan to build 11 UHVDC transmission projects. By then, a smart and strong grid with UHVDC transmission lines as the backbone will be built. The total DC transmission capacity will amount to 88 GW with total distance exceeding 40,000 km. 22
+-1100kV UHVDC - 2015
HVDC Testing Capacity UHV DC Test Base FACTS & VSC Test Base High Altitude ( 4310 m) Test Base Simulation Center HVDC P&C Test Center
FACTS Applications +120 sets of FACTS are in operation by SGCC 1000kV Series Compensation & Controllable Shunt Reactors 2011 5 Sets of 500kV Wide Are Control SVCs The big one: -480Mvar to +720MVar
Manufacturing Capacity 7 Domestic Converter Transformer Factories ( A 800kV 250MVA in < 170 days ) 3 DC Valves, DC Field Equipment Factories 3 HVDC P&C Factories One Smoothing Air Core Reactor Factory ( only one has 800kV installations in the world 2 High Voltage Submarine Power Cable Factories
Q&A Ready to Share Something Built in China Long Time Ago Still Stands. Dr. Wei Xiaoguang Senior Engineer weixg@epri.sgcc.com.cn Dr. Li Xiangyang Senior Engineer lixy@epri.sgcc.com.cn Mr. Jim Cai Senior Engineer jimcai@cet-int.com