KoCoS Blog

Ohm published his results in 1826 and initially received little recognition. It was not until 1841 that Ohm received the Copley Medal of the Royal Society of London, which corresponds to today's Nobel Prize, as an award for his work. In 1893, the World Electrical Congress in Chicago gave the designation "Ohm" (sign Omega: Ω) to the unit of electrical resistance.

With Ohm's torsion balance galvanometer, only the first step in the development of resistance measuring instruments is described in this article. The history of resistance measurement shows the changes from the age of early experimenters to today's computer age, i.e. from measuring bridges to the first electronic devices to today's digital measuring systems. Developers always used the latest ideas and systems to make the products more useful and user-friendly. Technological change drove the development of measuring instruments and realized technological advances.

Regular measurements of the static and dynamic contact resistance allow precise statements to be made about the condition of the entire contact system. Necessary maintenance work can thus be detected at an early stage and downtimes prevented. With the PROMET SE resistance measuring device, contact resistance measurements can be carried out on up to 12 or more interrupters and directly integrated into the overall test sequence. The test current can be set up to a maximum of 200 A. Even very small resistances in the single-digit microohm range can be measured with extremely high accuracy. The measured values are included in the evaluation of the test and output in the test report.

A high contact resistance within a switching device leads to a high power loss, combined with thermal stress and possible destruction of the switching device. Faults, such as high contact resistance due to defective connections, can be detected by measuring the static contact resistance. With the dynamic contact resistance measurement, the resistance curve is determined during a switching operation that can be defined as desired. The measurement allows, for example, conclusions to be drawn about the length and condition of arcing contacts in high-voltage switches.

Answer: Nothing! Because when we talk about GOOSE at KoCoS, we usually don’t mean the animal but the network protocol I protection technology. Further answers to the question of what GOOSE is all about and what role the latest ARTES update plays in this context can be found here. 

The IEC 61850 standard of the international Electrotechnical Commission (IEC) describes, among other things, a general transmission protocol for protection and control technology in medium and high voltage substations (station automation). One topic of this series of standards is the “Generic Object Oriented Substation Events”, in short GOOSE messages. 

But what is the significance of these GOOSE messages in a substation? 
In simple terms, GOOSE messages are used to exchange information such as status messages or excitation signals between the IEDs (Intelligent Electronic Devices) of the station. These information are distributed as an Ethernet packets via the process bus of the substation.

With an update to follow in the next few days, the test systems of the 4th ARTES generation can also be integrated into a corresponding environment to evaluate these signals. Thanks to the powerful signal processor of these test systems, they can be connected directly to the process bus, so that the evaluation of GOOSE messages can take place in real time.

Since a large number of GOOSE messages can be present in a network, but only the information of individual ones is of interest for the protection test, the exact structure of the required GOOSE message must be known. For the correct parameterization of ARTES test systems, a relay-specific configuration file is required. This file contains all information regarding the structure of the GOOSE message and its content. The ARTES 5 software analyses the configuration file and the desired signal can be selected.