ZZDFPZ ±100…±1100 kV converter transformers for DC transmission (LCC and VSC)
ZZDFPZ are converter transformers for DC lines of classes from ±100 to ±1100 kV, rated 404–850 MVA. The series covers line-commutated converter (LCC) links, back-to-back DC links and flexible VSC transmission from offshore wind farms.
- ±1100 kV
- ZZDFPZ-607500/750-1100: 607.5 MVA, (750 −5×0.86 %)/√3 / 236.2/√3 kV, uk 20 %
- ±800 / ±600 / ±400 kV
- ZZDFPZ-509400/500: 509.4 MVA, (530 −5×1.25 %)/√3 / 172.8/√3 kV, uk 21 %, ODAF
- ±200 / ±100 kV
- ZZDFPSZ-509400/500-200, ZZDFPSZ-404000/500-100 (back-to-back DC links)
- VSC (flexible DC)
- DFPSZ-RZ-460000/500: 460 MVA, (525/√3)/(437.23/√3)/66 kV; SSP-RZ-850000/220: 850 MVA for ±400 kV offshore wind farm
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Converter transformers supply the converters of DC substations. They convert the AC voltage for rectification to DC and electrically separate the AC and DC networks. The manufacturer built the industry's first ±800 kV converter transformer for the Yunnan–Guangdong link and the first ±1100 kV unit for the Changji–Guquan link. It has supplied equipment for the Wudongde–Guangdong/Guangxi multi-terminal link, the Ningxia–Hunan and Gansu–Shandong links, and transformers for a ±500 kV VSC link in Saudi Arabia.
The flagship single-phase ZZDFPZ-607500/750-1100, rated 607.5 MVA, has voltages of (750 −5×0.86 %)/√3 and 236.2/√3 kV and a short-circuit voltage of 20 %. Insulation and bushings are designed for the ±1100 kV class. Per the manufacturer, the insulation levels of the line winding are LI1950 SI1550 AC900 and LI185 AC95 for the neutral, and of the valve winding LI2300 SI2100 AC1297 DC1791, Umpol 1386 kV. The ratio of conductor size to oil duct size is chosen so that the windings heat evenly. Stray-field suppression and an oil-directing system remove local overheating and oil electrification.
For ±800, ±600 and ±400 kV links the manufacturer makes single-phase two-winding ZZDFPZ-509400/500 units rated 509.4 MVA, with voltages of (530 −5×1.25 %)/√3 / 172.8/√3 kV, a short-circuit voltage of 21 % and ODAF cooling. In the ±800 kV version no-load loss is up to 227 kW and short-circuit loss up to 1309 kW, and the valve winding insulation is SI1675 LI1870 AC1h938 DC1296 PR1006 kV. The design is explosion-proof, with increased resistance to burning and explosion, and its dimensions are compact for rail transport.
Transformers for ±200 and ±100 kV rated 509.4 and 404 MVA, including the three-winding ZZDFPSZ, work in back-to-back DC links that connect non-synchronous networks. They are equipped with online monitoring and an emergency oil drain system.
For voltage-source converter links there are the DFPSZ-RZ-460000/500 rated 460 MVA ((525/√3)/(437.23/√3)/66 kV, OLTC, no-load loss 216 kW and short-circuit loss 900 kW) and the SSP-RZ-850000/220 rated 850 MVA. The latter delivers the output of an offshore wind farm over a ±400 kV link, has C5-M anti-corrosion protection, is vibration-resistant and operates with low partial discharge.
Technical specifications
| ±1100 kV | ZZDFPZ-607500/750-1100: 607.5 MVA, (750 −5×0.86 %)/√3 / 236.2/√3 kV, uk 20 % |
|---|---|
| ±800 / ±600 / ±400 kV | ZZDFPZ-509400/500: 509.4 MVA, (530 −5×1.25 %)/√3 / 172.8/√3 kV, uk 21 %, ODAF |
| ±200 / ±100 kV | ZZDFPSZ-509400/500-200, ZZDFPSZ-404000/500-100 (back-to-back DC links) |
| VSC (flexible DC) | DFPSZ-RZ-460000/500: 460 MVA, (525/√3)/(437.23/√3)/66 kV; SSP-RZ-850000/220: 850 MVA for ±400 kV offshore wind farm |
| Losses (±800 kV) | no-load ≤227 kW, short-circuit ≤1309 kW |
| Valve-side insulation (±800 kV) | SI1675 LI1870 AC1h938 DC1296 PR1006 kV |
| Transport | compact design within rail gauge |
Replacement for
no direct equivalent (HVDC converter transformers are not series-produced in the CIS)
selected by purpose and main parameters, please confirm with our manager
Request a price and lead time
ZZDFPZ ±100…±1100 kV converter transformers for DC transmission (LCC and VSC). We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8504 23 00 00 |
|---|---|
| HS, 6 digits | 8504 23 |
| CN (EU) | 8504 23 00 |
| HTSUS (USA) | 8504 23 00 80 |
| China customs tariff | 8504 23 10 00 8504 23 20 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
What is the highest voltage class of the converter transformers?
±1100 kV. The single-phase ZZDFPZ-607500/750-1100 rated 607.5 MVA has a short-circuit voltage of 20 %; the manufacturer supplied the first such unit for the Changji–Guquan link.
Can the transformers be transported by rail?
Yes, the ZZDFPZ-509400/500 models for ±800, ±600 and ±400 kV links have compact dimensions for rail transport. They are rated 509.4 MVA with ODAF cooling.
What is available for VSC links from offshore wind farms?
The SSP-RZ-850000/220 rated 850 MVA for a ±400 kV link, with C5-M anti-corrosion protection. For onshore VSC links there is the DFPSZ-RZ-460000/500 rated 460 MVA with OLTC.
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