Electrical Engineering Division
Arc suppression coils
Earth (ground) fault arc suppression coils (Petersen coils)
Arc suppression coils (Petersen coils) are used for compensation of capacitive currents when earth (ground) faults occur on an electrical network. They are connected to the distribution network node. EGE’s arc suppression coils are smoothly adjustable arc suppression coils covering:
- network rated voltage 6kV up to 110kV
- rated power 125 kVA -19000 kVA
- rated frequency 50 Hz
- duty – short time (KB-2h)
- – continuous duty (DB)
- standard current range 10 – 100 % In
The basic requirements demanded of such items conform to the IEC 60076-6 standard, with the exact design of the arc suppression coil being adapted to the specific needs of clients.
EGE also provides special design of arc suppresion coils - earthing transformer active part can be placed together with an active part of an arc suppression coil in a shared housing. This solution is known as combined arc suppression coil.
Other EGE's products can be customised according to the needs of clients:
- ASC current indicator - type DU
- Uo voltage indicator
Earthing transformers - ETR
ETR earthing (grounding) transformers are used to create an artificial neutral in distribution electric networks.
Typical parameters of ETR earthing transformers are:
- networks of 6, 10, 15, 20, 35, 52 kV
- rated power from 200 to 8000 kVA
- wiring scheme ZN, ZNyn 11 or other variants based on customer´s wishes.
Resistors for increasing active components of fault current
Secondary resistors are used in order to improve the reliability of earth (ground) fault directional protection instruments. The resistors enable active components of the fault current to be increased for a short time.
The connection is either controlled by the tuning controller of an arc suppression coil, or another device from EGE – the ARS resistor controller. All resistors supplied by EGE are suitable for outdoor environments and are cooled by natural air circulation.
Alternatively, EGE can provide a sophisticated SRA type of resistor. Each of these consists of several resistor elements. Connecting the elements in various ways via contactors makes it possible to obtain a number of resistance values. These resistors are governed by ARS controllers, which select a suitable resistance value based on parameters measured in the network.
ARS resistor controllers
ARS resistor controllers are microprocessor-based devices for automatic control of resistor connections to the auxiliary power windings of arc suppression coils. Their design enables them to be installed directly in the control box of the resistor or in the terminal boxes of arc suppression coils.
Earthing resistors for MV networks
Earthing resistors serve connections between the neutral points of distribution network to grounds in networks operating with resistor-grounded neutral points. The purpose of the resistor-grounded neutral is to dampen overvoltage during ground faults and provide sufficient current values for protection, causing the affected network section to trip rapidly. Cooling of such components is facilitated via natural air circulation.
Three-phase shunt reactors
TKFC – Three-phase shunt reactors are used to compensate the reactive power.
With the development of renewable electric power sources (above all offshore and land wind farms and solar power plans) the compensation of reactive power gains more significance.
TKFC - 3-Phase shunt reactors are designed as fixed shunt reactors for a fixed power or with taps and off-load tap-changer for adjustment to various values of reactive power.
Typical parameters of the TKFC reactors are:
networks of 6, 10, 15, 20, 35 kV
power up to 8000 kVA
connection group Y or YN
Design: hermetically sealed tank or with expansion tank and air breather.
Ripple control coupling transformers
Coupling transformers are intended for application in MV and HV networks as a part of a solid-state transmitter. They allow sonic frequency impulses to be transmitted from solid-state transmitters to MV and HV networks. Coupling transformers for HV networks are filled with transformer oil, whilst those for MV networks are air cooled.
Multifrequency current injector MCI P‑01
Multifrequency current injector MCI P‑01 is a brand-new generation of current injectors used for reliable tuning of arc suppression coils in resonant-grounded networks
The current injector MCI P‑01 is a perfect solution for cases, where standard resonant method of tuning is not reliable and sufficient, especially in networks with.:
- very low value of Uo (balanced networks) – typically cable networks
- rapidly changing Uo voltage (Neutral Voltage Displacement) caused by fluctuations of load or distributed energy resources.
MCI P‑01 injects multifrequency current signal through the power auxiliary winding of the arc suppression coil, measures the voltage response of the network, evaluates network parameters and determines the Uo voltage characteristic and the resonant point, which is necessary for reliable arc suppression coil adjustment.
MCI P-01 is a compact device that can be installed directly in a control box of the arc suppression coil or in a switchboard together with the arc suppression coil controllers.
MCI P‑01 has following advantages compared to rival brands:
- continuous injection and evaluation of the network parameters during the tuning process
- there is no need of external neutral point voltage measurement - no external VT required
- compact dimensions, very low demand on power supply, RCCB can be used for power supply of MCI
- simple installation (only three cables necessary in some cases)
- fundamental frequency of the network does not affect its function
- low injected power necessary even for large networks
MCI P-01 cooperates with REG-DP and REG-DPA controllers manufactured by A. Eberle GmbH & Co. KG.
The injector is parametrized through their user interfaces. The controllers also mediate the communication with a control system (e.g. SCADA).