References
2008 Greenbank & South Pine, Australia
In April 2007 Siemens Energy was awarded a turnkey contract for two SVCs at Greenbank and South Pine substations in the South East Queensland (SEQ) 275 kV grid of Australia. With the installation customer Powerlink planned to provide sufficient power compensation and to add additional voltage support to the greater area of Brisbane by dynamic reactive power compensation.
The SVCs have a nominal three swing range of 100 MVAr inductive to 250 MVAr capacitive with an overload of up to 350 MVAr for one hour. Each SVC consists of one thyristor controlled reactor (TCR), two thyristor switched capacitors (TSC) and three fixed filter circuits for harmonics.
As turnkey contractor, Siemens was responsible for design engineering, delivery, civil and assembly works as well as site testing. Transformers were manufactured locally in Australia by Areva; Siemens Germany delivered valves, control & protection (C&P) and capacitors. The reactors were manufactured in Canada by Trench.
Whereas both sites had the same completion date Siemens managed to sequence individual tasks for each project in a sequential order and thus optimized manpower and workflow during construction, installation and commissioning periods. The successful team effort by the international management team achieved the practical completion for both sites on time. Greenbank and Southpine SVCs entered in operation in 2008.
| Customer | Powerlink |
| System Voltage | 275kV / 50 Hz |
| Transformer | |
| Operating range | +250 MVAr (capacitive) overload +350Mvar to to -100 MVAr (inductive) |
| Definition of SVC Branch circuits | 1 x TCR 2 x TSC 3 Filters |
| Thyristor | 5” diameter 8 kV blocking voltage |
| Valve type | |
| Valve cooling system | single circuit, de-ionized water |
| Digital control system | SIMADTIC TDC® |
2007 Railways & Nebo, AUSTRALIA
Nebo: Just five months delivery time for a TSC-Valve
In spring 2005 the refurbishment of Powerlink´s Nebo SVC (originally built by a competitor) was awarded to Siemens. The scope of work for this SVC, consisting of a Thyristor Switched Capacitor (TSC) and Thyristor Controlled Reactor (TCR) branch, included the thyristor valves and accessories, the thyristor cooling system and the complete control and protection system.
Since TSC plays an important role in Powerlink´s network, the contract was divided into two parts, the first of which placed two major challenges.
- To replace the damaged TSC valve in only two months – and to integrate a Siemens TSC valve into a competitor´s control and protection system. The key to success was very detailed status quo investigation including thorough checks of all interfaces – and minute logistic planning.
- The complete Control and Protection System and the TCR valve were successfully refurbished and Powerlink took over the complete refurbished SVC even before the contractual date of practical completion.
Railways: A 48-hours outage solution from Siemens supporting an important railway system
At almost the same time as the Nebo project, Powerlink placed another refurbishment order for nine SVCs in their network. These SVCs are supporting an important railway system in central Queensland used for transporting coal from the inland mines to the coal terminals at Queensland´s coastline. The scope of work included the replacement of the thyristor valves, the cooling system and the web based control and protection system, which encompasses the remote control of the SVCs. To support the coal transport system´s reliability, the SVCs had to remain in service as long as possible throughout the refurbishment project.
Only Siemens was able to offer a solution that limited the outage time per site to 48 hours: This was achieved by introducing a mobile SVC solution that can be used during the main refurbishment work on each site. Thus, shutdown is only required to re-establish connection to the mobile system after disconnecting the existing system and, of course, for testing. The Railway SVC refurbishment project is scheduled to be completed at end of 2007.
| Railways | Nebo | |
| Customer | Powerlink, Australia | Powerlink, Australia |
| System Voltage | 275 kV/50Hz | 275 kV/50Hz |
| Transformer range | 275/17.7 kV | 275/17.7 kV |
| Operating range | + 260 MVAr up to –80 MVAr (inductive) | + 260 MVAr up to (capacitive) –80 MVAr (inductive) |
| Definition of SVC Branch circuits | 1 x TCR 1 x TSC 2 x STF |
1 x TCR 1 x TSC 2 x STF |
| Thyristor | 125 mm Ø, 4 kA, 8 kV | 125 mm Ø, 4 kA, 8 kV |
| Valve type | 8 kV light-triggered-thyristor | 8 kV light-triggered-thyristor |
| Valve cooling system | Single-circuit with de-ionized water | Single-circuit with de-ionized water |
| Digital control system | SIMADTIC TDC® | SIMADTIC TDC® |
2006 Radsted, Denmark
An SVC, that controls voltage fluctuations caused by an offshore wind park
SEAS-NVE, the largest utility in Denmark operates the Nysted Offshore Wind park located south of the island of Lolland. Voltage fluctuations caused by this facility lead to voltage stability problems in the 132 kV transmission system. In June 2005, Siemens was awarded a turkey project for the construction of an SVC located on the island of Lolland. It provides the necessary reactive power balance for the system helps to improve voltage quality and increases system stability.
Siemens offered a special solution for this project: the SVC has a 12-pulse configuration consisting of a TCR (Thyristor Controlled Reactor) and a filter in each of the two secondary circuits of the 3-winding step-down power transformer. One of the transformer´s secondary winding is connected in star, while the other is connected in delta.
The delivered high-pass filters are tuned to the 11th harmonic and are connected in star. The 12-pulse configuration has the advantage that due to the phase shift in the two secondary busbars of the SVC, the 5th, 7th, 17th, and 19th harmonics produced by each of the TCR branches cancel each other out, helping to meet the stringent harmonic requirements.Furthermore Siemens took special care to fulfill the customer´s requirements in terms of noise reduction and architectural appearance. Therefore, the SVC was completely housed in a “barn-type” building equipped with special sound muffling materials and components. The buildings height was kept below 6 meters, made possible by optimizing the equipment configuration inside.
| Customer | SEAS-NVE, Denmark |
| System Voltage | 132 kV/50Hz |
| Transformer | 3-winding type |
| Operating range | + 80.2 MVAr (capacitive) to –65 MVAr (inductive) |
| Definition of SVC Branch circuits | 12-pulse configuration 2 x TCR 2 x Filters |
| Thyristor | 125 mm Ø, 4 kA, 8 kV |
| Filter frequencies (harmonics) | 550 Hz (11th) |
| Valve type | 8 kV light-triggered-thyristor |
| Valve cooling system | Double-circuit with de-ionized water/water glycol mixture |
| Digital control system | SIMATIC TDC® |
2006 Devers, USA
Strengthening the transmission path between Arizona and California
One of the largest SVCs in the US is located at Devers 500kV substation, near Palm Springs, California. The Devers SVC was ordered by SCE (Southern California Edison) as a turnkey project in September 2005 to strengthen the Devers-Palo Verde transmission path from Arizona to California. Since it was put into commercial operation in September 2006 the SVC adds additional voltage support to the Palm Springs area, thus SCE can increase its import transmission capability from Arizona during high demands period.
The full capacitive output of the SVC of 330 MVAr is provided by two TSC branches and two filter branches. The capacitive output of 440 MVAr for 1 h is provided by three TSC branches, two filter branches and one TCR in operation. The SVC´s full inductive output of 110 MVAr is provided by two TCR branches operating in parallel with the filters.
In addition to the SVC, a MSC of 165 MVAr connected to the 525 kV bus was included in the scope of supply, conforming a Static Var System (SVS) with total capacitive output of 605 MVAr.
| Customer | SCE, USA |
| System Voltage | 525 kV / 60 Hz |
| Transformer | 4 x 100 MVA |
| Operating range | + 330 MVAr up to – 110 MVAr (inductive) + 440 MVAr capacitive for one hour |
| Definition of SVC Branch circuits | 2 x TCR 3 x TSC 2 x Filters |
| Thyristor | 125 mm Ø, 4 kA, 8 kV |
| Filter frequencies (harmonics) | 300 Hz (5th) 420 Hz (7th) |
| Valve type | 8 kV light-triggered thyristor |
| Valve cooling system | Double-circuit with de-ionized water/water glycol mixture |
| Digital control system | SIMATIC TDC®, redundant |
2005/2006 Porter and Ninemile, USA
Application of Static Var Compensators in Entergy´s system to address voltage stability issues
Based on planning studies, two major load centers (The Westbank area near New Orleans and the Woodlands area just north of Houston) in Entergy´s network were identified as areas with potential voltage stability problems.
After evaluation of technical, economical and reliability factors, SVCs were considered as the preferred solution for both of these areas. In conjunction with Entergy´s SVC design specifications, two SVCs and a Fixed Series Capacitor (FSC) were awarded on a turnkey basis to Siemens Power Transmission and Distribution in 2004.
The first 300 MVAr SVC was commissioned at the Ninemile 230 kV station in the New Orleans area in May 2005. The second 300MVAr SVC at Porter 138 kV station as well as the new FSC at Dayton Substation entered into operation in Entergy´s Western Region near Houston, Texas in April 2006.
| Customer | Entergy, USA |
| System Voltage | 230 kV/60 Hz (Ninemile) 138 kV/60 Hz (Porter) |
| Transformer | 4 x 100 MVA each SVC |
| Operating range | + 300 MVAr (capacitive) to 0 MVAr (inductive) |
| Definition of SVC Branch circuits | 3 x TSC |
| Thyristor | 125 mm Ø, 4 kA, 8 kV |
| Filter frequencies (harmonics) | Not applicable |
| Valve type | 8 kV light-triggered-thyristor |
| Valve cooling system | Double-circuit with de-ionized water/water glycol mixture |
| Digital control system | Redundant |
2004 Siems, Germany
The first utility SVC in Germany
The HVDC Baltic Cable (with a transmission capacity of +/- 600 MW) was constructed in the early nineties to link the power systems of Germany and Sweden. To ensure optimum dynamic operation of the system it was originally planned to connect the HVDC converter station Herrenwyk located in Germany to the 380 kV grid. However, due to changes in the European power market this connection was abandoned and the HVDC link was consequently connected to the 110 kV network in the Lübeck district, which is inadequately dimensioned in terms of necessary system impedance.
Due to this reason and based on detailed network studies, E.ON decided to carry out several extensions in the northern German power network between 2003 and 2004. In conjunction with these extensions and considering the highly dynamic behavior of the HVDC converter station at Herrenwyk, E.ON Netz GmbH awarded a contract to build a new SVC on the former site of the Lübeck-Siems power plant in November 2003, in order to ensure voltage quality in its northern 380 kV grid.
The Thyristor Controlled Reactors had to be built indoors to fulfill very stringent requirements regarding noise emissions, using special noise damping materials and methods. The project also included the first-ever implementation (in an SVC) of the high-reliable control system based on SIMATEC TDC®, a proven industrial hardware design from Siemens. The SVC was successfully put into commercial operation only 12 months after the contract had been signed.
| Customer | E.ON Netz GmbH |
| System Voltage | 380 kV / 50 Hz |
| Transformer | 200 MVA |
| Operating range | + 200 MVAr (capacitive) to – 100 MVAr (inductive) |
| Definition of SVC Branch circuits | 1 x TCR 1 x TSC 1 x STF (ν = 5) 1 x DTF (ν = 7, 11) |
| Thyristor | 125 mm Ø, 4 kA, 8 kV |
| Filter frequencies (harmonics) | 250 Hz (5th) 350 Hz (7th) / 550 Hz (11th) |
| Valve type | 8 kV light-triggered thyristor |
| Valve cooling system | double-circuit with de-ionized water/water glycol mixture |
| Digital control system | Simatic TDC®, redundant |
2002 Bom Jesus da Lapa, BRAZIL
The largest SVC in South America built in record construction time
This Static Var Compensator located at the 500 kV Bom Jesus da Lapa II substation, maintains voltage stability over the 1100 km long 500 kV overhead transmission line between the Serra da Mesa substation and the Sapeaçu substation near Salvador in the northeast of the country.
This large Siemens SVC with a control rating of 500 MVAr was built in the record time of only 12 months for the Italian ENELPOWER utility company to strengthen the east-west grid interconnection in Brazil´s northeast under the project name "Interligação Sudeste - Nordeste". Similar to the solution for the Funil SVC, all electronic power components needed for compensation were installed in steel containers.
Since its commissioning in December 2002, the SVC at the Bom Jesus da Lapa II substation has been stabilizing voltage and frequency across the grid, minimizing losses and responding swiftly and reliably to load changes.
| Customer | Enelpower, Brazil |
| System Voltage | 500 kV / 60 Hz |
| Transformer | 4 x 83.3 MVA |
| Operating range | + 250 MVAr (capacitive) to – 250 MVAr (inductive) |
| Definition of SVC Branch circuits | 2 x TCR 1 x TSC 2 x Filters |
| Thyristor | 125 mm Ø, 4 kA, 8 kV |
| Filter frequencies (harmonics) | 300 Hz (5th) 420 Hz (7th) |
| Valve type | 8 kV light-triggered thyristor |
| Valve cooling system | Single-circuit with de-ionized water |
| Digital control system | SIMADYN D® |
1995 Impala, Illovo & Athene, SOUTH AFRICA
Voltage stability to ensure security of power supply
Richards Bay is a major industrial centre of the Republic of South Africa with aluminum smelter plants, paper mills and open-cast Mining, among others located in the region. With the main generation centers of the Transvaal over 200 km away, maintaining a stable and secure supply to this region is critical. In 1994 and 1995 Siemens successfully installed three Static Var Compensators for the South African Utility ESKOM (Electricity Supply Commission) at their 275 kV substations (Impala and Illovo) and at their newly built 400 kV substation Athene. The NATAL Static Var Compensators are designed for:
- Fast dynamic network stabilization (voltage stabilization)
- Reduction of voltage unbalance
- Reduction of network disturbances
- Increasing of transmission capability
- Control of external reactive-power devices
| Customer | ESKOM, South Africa |
| System Voltage | 275 kV/50 Hz; 400 kV/50 Hz |
| Transformer | 4 x 66.7 MVA |
| Operating range | + 100 MVAr (capacitive) up to –200 MVAr (inductive) 8-300 MVAr (inductive) for 10 s |
| Definition of SVC Branch circuits | 2 x TCR 3 x Filters |
| Thyristor | 100 mm Ø, 4 kA continuous current 5,5 kV blocking voltage |
| Filter frequencies (harmonics) | 150 Hz (3rd) 250 Hz (5th) 350 Hz (7th) |
| Valve type | 5,5 kV electrically-triggered-thyristor |
| Valve cooling system | Single-circuit, de-ionized water |
| Digital control system | SIMADYN D® |