SCHNIEWINDT GMBH & CO. KG - The Power of Electrifying Ideas

CSN® PreInsertion Resistors are used for limitation of transients during energisation process of transformers and HVDC VSC converter applications. CSN® Discharge Resistors are used for discharge of Capacitors, reactors and superconducting magnetic field coils. They are characterized by a high dielectric strength and energy absorption capacity. CSN® PreInsertion or Discharge Resistors are designed and manufactured individually to customer requirements and specific application.

CSN® Protection Resistors are used for protection of electric equipment in case of shortterm peak currents. Due to the high capacity of energy absorption, CSN® Protection Resistors can absorb several kiloamperes for a limited period of time, protecting connected modules.

CSN® Dummy Load Resistors used as dummy loads for testing high frequency radio transmitter systems. Schniewindt had already supplied dummy load resistors with rated max. cont. power up to 1500 kW. CSN® Dummy Load Resistors are designed and manufactured individually to customer requirements and specific application.

CSN® Insulator Heaters are used in flue gas cleaning systems for preheating the insulators and as protection of the equipment against condensation and freezing during shutdown periods

For the majority of the resistor units manufactured by Schniewindt, the design is based on CSN® Resistor Webs. For manufacturing the resistor webs, resistive wires are woven meander shaped into temperature resistant insulation yarn. Besides the excellent high voltage strength and the typedependent low inductivity of the resistor webs, these webs are additionally suitable for high specific load operation due to the excellent convection conditions of the resistor web design. By selecting special high grade resistive alloys for manufacturing of the resistor webs, resistor units for operation under almost any environmental condition can be developed

The CSN® type RCVoltage Dividers consist of a proven reliable and high accuracy resistivecapacitive voltage divider. These are used for voltage measurement for control and protection systems in HVDC links and research institutes. The base for our Voltage Dividers are metal wire resistor webs that have been embedded in epoxy resin under vacuum. In this way, optimal protection against external influences can be achieved. Depending on the installation requirements (outdoor or indoor application), special designs of the voltage dividers adapted on the site requirements are used. The insulation medium (air, N2, SF6) can be easily adapted to the special requirements of the application. Our CSN® RCVoltage Dividers are characterized by

CSN® Current Sensors are used for current measurement in control and protection systems in power transmission links (AC and DC applications). The CSN® type Current Sensors are based on highaccuracy resistive sensors (shunt) respectively iron free cores (CSN® AirCoil). There are selfsupporting structures available where the CSN® Current Sensor is mounted on top of a composite insulator, as well as variants in which the CSN® Current Sensor will be mounted hanging in the busbar. Schniewindt has implemented CSN® Current Sensors for nominal currents of up to 5 kADC at system voltages of 800 kVDC, which have been successfully typetested. Also for the precise measurement of small currents (1 to 10 A), such as transient currents in capacitor banks, Schniewindt offers appropriate solutions. All of our CSN® Current Sensors are individually designed according to customer requirements.

The IEC 6185092 LE Merging Unit is the optimal solution for process bus interfacing. It allows the consolidation of measurements made in the switchyard, feeding protection relays, meters and fault recorders located in the control room. The use of fiberoptical communications makes it inherently safe. By eliminating the majority of copper wiring, the CSN® Merging Unit addresses key technical and logistic challenges affecting the cost of substation design, construction and maintenance. The simple and disturbancefree architecture of the open IEC 6185092 process bus allows operation of relay, meter and faultrecording equipment of different manufacturers on the same bus. The IEC 6185092 LE Merging Unit collects data from conventional instrument transformers and converts the analog signals into a digital protocol

The CSN® SV Viewer (Sampled Values) is our solution for visualizing and recording the digital IEC 6185092 LE Protocol. This software allows the user to visualize the current and voltage values of different Merging Units. The function Values displays the eight current and voltage values. Additionally it is possible to display a DC offset. In realtime mode, a selectable value is shown continuously. The function Phasor calculates the phase shift between the sampled values channels. The function Waveforms charts the sample values of different Merging Units. The user can add or remove the desired sample values. The waveform can be saved as a screenshot or can be printed by the integrated print function. The function Recorder allows the user to record up to two data streams on the hard drive either as .txtfile, Microsoft Excel Spreadsheet or in COMTRADE format. The .txt files can normally be handled by any spreadsheetsoftware; no special analysis software is required.

The CSN® AirCoil is a special design based on the physical construction of a Rogowski Coil. Due to the ironfree design the coil does not have any saturation which allows to use only one CSN® AirCoil Module for both metering and protection arrays. Additionally the CSN® Aircoil shows linear transmission behaviour over a wide frequency range. A current range of hundred amperes up to several hundreds kiloamperes is easy to realize. CSN® AirCoil Modules are combinable and hence the output voltage level is adjustable to customer request. The very compact design with an excellent longterm stability are additional benefits for special applications. Further information about our CSN® AirCoil