HVDC Switches

Switches for HVDC applications are designed to close and open very rapidly in case of fault or for maintenance purposes. The switches may have to commutate load current while maintaining the flow of power within DC substation and its availability.

All HVDC switches are activated by the highly reliable spring-spring mechanism and benefit of a huge experience and installed base of AC circuit-breaker technology delivered worldwide in regards to design technology, to quality in terms of supplier qualification, assembly processes and ISO conformity.

• DC current switching
• Dielectric withstand in open position over long time intervals
• High creepage distances require a long column
• Optional Features:
  
  • Use of surge arresters in addition to capacitors
  • Low temperature or seismic applications
  • CBWatch3 Monitoring System
  • Closing resistors for special applications

HVDC Switches

Where more than one HVDC Pole share a common transmission conductor (typically the neutral) it is advantageous to be able to commutate the DC current between transmission paths without interrupting the DC power flow.

NBGS – Neutral Bus Ground Switch

This switch is normally open but when closed it solidly connects the converter neutral to the station earth mat. Operation with this switch can normally be maintained if the converter can be operated in a bipole mode with balanced currents between the poles, that is, the DC current to earth is very small. The switch is also able to open, commutating a small DC unbalance current out of the switch and into the DC circuit.

NBS – Neutral Bus Switch

A NBS is in series with the neutral connection of each pole. In the event of an earth fault on one pole, that pole will be blocked. However, the pole remaining in service will continue to feed DC current into the fault via the common neutral connection. The NBS is used to divert the DC current away from the blocked pole to ground.

GRTS – Ground Return Transfer Switch

The connection between the HVDC conductor and the neutral point includes both a high voltage disconnector and a GRTS and is used as part of the switching operation to configure the HVDC scheme as either a ground return monopole or a metallic return monopole. The disconnector is maintained open if the HV conductor is energized in order to isolate the medium voltage GRTS from the high voltage.

The GRTS is closed, following the closing of the disconnector in order to put the HV conductor in parallel with the earth path. The GRTS is also used to commutate the load current from the HV conductor transferring the path to the earth (or ground return) path. Once current flow through the HV conductor is detected as having stopped, the disconnector can be opened, allowing the HV conductor to be re-energised at high voltage.

MRTB – Metallic Return Transfer Breaker

The MRTB is used in conjunction with the GRTS to commutate the DC load current between the earth (ground return) and a parallel, otherwise unused, HV conductor (metallic return).

The MRTB closes in order to put the low impedance earth return path in parallel with the metallic return path. The MRTB must also be able to open, causing current flowing through the earth return to commutate into the much higher impedance metallic return path.

Dead Tank Circuit Breakers

GE offers a comprehensive range of dead tank circuit breakers that support a voltage rating up to 550 kV, and are capable of carrying a continuous current up to 5,000 A. GE's circuit breakers meet or exceed the latest IEEE/ANSI and IEC standards, including C2 and M2. They can be gang operated up to 245 kV, and Independent Pole Operation (IPO) is available at all voltage levels.

The DT Series from GE is characterized by advanced self-blast interrupters, leak resistant cast aluminum enclosures and durable low energy mechanisms. More than 120,000 circuit breakers with self-blast interrupters and spring-spring operated mechanism have been in service since 1989, including more than 30,000 dead tank circuit breakers.

The SF6 dead tank circuit breakers assure a high level of reliability on a daily basis, even under extreme conditions such as low temperatures, highly active seismic areas, regions with high pollution levels, and a corrosive atmosphere.

GE's Dead Tank Circuit Breakers, the DT Series, supports system voltages from 38 kV to 550 kV and are designed for reliable performance, maximized safety and lower cost of ownership. The DT Series is designed to operate within extreme environmental conditions including high elevation, very low and high temperatures (-60 °C to +60 °C ), seismic zones, polluted areas and corrosive atmospheres.

1. DT1-38
   Dead Tank Circuit Breaker for 38 kV / 40 kA
2. DT1-72.5
   Dead Tank Circuit Breaker for 72.5 kV / 40 kA
3. DT1-145 and DT1-170
   Dead Tank Circuit Breakers for 123 kV, 145 kV and
   170 kV / 40 kA
4. DT1-145 63
   Dead Tank Circuit Breaker for 123 kV and
   145 kV / 63 kA
5. DT1-245P
   Dead Tank Circuit Breaker for 245 kV / 40 kA
6. DT1-245P 63
   Dead Tank Circuit Breaker for 245 kV / 63 kA
7. DT1-362
   Dead Tank Circuit Breaker for 362 kV / 63 kA
8. DT2-550
   Dead Tank Circuit Breaker for 550 kV / 63 kA

XD/GE Dead Tank Circuit Breakers
XD|GE offers a comprehensive range of Dead Tank Circuit Breakers that support a voltage rating up to 800 kV and are capable of carrying a continuous current up to 5000A. For circuit breakers rated 363kV and above, the design features a fully integrated, maintenance free, hydro-mechanical operating mechanism, maximizing device stability and long-term reliability.

Generator Circuit Breakers

Increased Availability, Enhanced Protection and Simplified Operations for Power Plants
GE's Generator Circuit Breakers (GCBs) are ideally suited for new and refurbished power plants from 50 MW to 1,500 MW and feature advanced technology with spring-spring-operated mechanisms. The comprehensive GCB portfolio provides solutions from generator circuit breakers without enclosure to customized solutions including disconnector, earthing switch, starting switch and instrument transformers.

• GCB ranges FKG1, FKG2 and FKGA
• Spring-spring operated mechanism for utmost reliability
• Optimized, preventive maintenance with monitoring system
• Breaker natural cooling up to 30,000 A and enhanced cooling up to 40,000 A
• 3,000+ GCB installations and 40+ years of expertise
• Optimized digital smart cooling solution optimizing ventilation system in real time
• Digital proxy communication including IEC 61850 and Modbus TCP

Equipment for Power Plants from 50 to 200 MW

1. FKG2S without enclosure
   Generator circuit breaker for power plants
   from 50 to 150 MW
2. FKG2S
   Generator circuit breaker for power plants
   from 50 to 150 MW
3. FKG2M
   Generator circuit breaker for power plants
   from 100 to 200 MW

Equipment for Power Plants from 150 to 450 MW

1. FKG1N without enclosure
   Generator circuit breaker for power plants
   from 150 to 300 MW
2. FKG1N
   Generator circuit breaker for power plants
   from 200 to 300 MW
3. FKG1F
   Generator circuit breaker for power plants
   from 300 to 450 MW
4. FKGA2
   Generator circuit breaker for power plants
   from 200 to 450 MW

Equipment for Power Plants from 450 to 1,000 MW

1. FKG1X
   Generator circuit breaker for power plants
   from 450 to 600 MW
2. FKG1XV
   Generator circuit breaker for power plants
   from 750 to 900 MW
3. FKG1XP
   Generator circuit breaker for power plants
   from 600 to 750 MW
4. FKG1XW
   Generator circuit breaker for power plants
   from 900 to 1000 MW

Equipment for Power Plants from 700 to 1,500 MW

1. FKGA8
   Generator circuit breaker for power plants
   from 700 to 1,500 MW

HYpact

HYpact is a hybrid compact switchgear assembly that typically consists of circuit breakers, disconnectors, and earthing switches located in a common gas tank. Current and voltage transformers can be added and the standard SF6 to air bushings can be replaced with cable connectors. Its modular design allows for a large variety of different layout configurations and enables a more economical substation design.

HYpact is well suited for heavily polluted environments and is the high-performing choice in regions exposed to seismic activity. Its compact design with low center-of-gravity is ideal for withstanding seismic acceleration, as proven by shaking table tests and finite elements method simulations. HYpact customers also benefit from long maintence-free periods with reduced exposure to environmental influences and a low number of bushings and moveable contacts.

Compact Switchgear

Compact switchgear

GE’s Compact Air-Insulated Breaker Assembly (CABA) is a modular, compact switchgear system combining a live tank circuit breaker, double sided disconnect switch and other AIS equipment mounted on a common frame. It can be installed in greenfield substations or retrofit into an existing substation. CABA can be installed on existing foundations and is designed for space savings due to its compactness.

This flexible, compact breaker assembly is well suited for a variety of applications including transformer protection, line and cable switching, capacitor bank and back-to-back switching, reactor switching and circuit switching.

Circuit Breaker Digital Solutions

GE’s Digital Solutions for Circuit Breakers provide operators with the actionable intelligence and controls needed to ensure asset performance while reducing maintenance and operational costs. Through non-invasive sensors, these solutions provide active monitoring and control of key operational parameters and functions.

CBWatch Circuit Breaker Monitoring

• Compact and modular online monitoring solution for high voltage circuit breakers
• Improves operational availability with health and condition-based monitoring of key performance parameters
• Able to detect even small SF6 leaks to optimize gas refill operations

CSD100 Point-on-Wave Controller

• Mitigate switching transients
• Enables reliable connection of intermittent power generation sources to the grid
• Provides advanced switching of reactive power compensation and long overhead lines