We have to extend an old project where relay protections in 20 kV switchgear are REF541/543. To keep the system similar new cubicles are equipped with the same REF541.
Of course all installation of the software is missing (even that old laptop is scrapped) and I have to install it again.
I use...
I am control and protection designer, in our every day work we use several kinds of design software for circuit diagrams design and system modeling. But I am curious what kind of software is used for design of primary part of outdoor switchgears. There are very complicated problems related to...
I would like to know about current practice for accreditation of inspection bodies acc. to IEC 17020. Who has a legal right to audit and issue accreditations ? If it is restricted only to national accreditation institutions or private ones can also obtain accreditation from "European...
I posted this question on another forum, but still there is no much activity there. My case is following:
I have a project now where I am going to realize part of protection logic by GOOSE messages between relay protections on different bays. Logic itself is not very complicated, no problem to...
I need advice from colleagues with experience relay protection tester FREJA 300 from Programma Electric. Tester is more or less OK for our needs, but we have very unpleasant problem with communications to it.
Connection to the tester is via COM port only. In some days connection is established...
For current tender we have to offer extension of mosaic type control panel in existing substation. Could somebody advice me where to find manufacturer of components for such panels?
Project is in Europe. Unfortunately we are just subcontractors, but during the site visit the Main contractor's...
With a current project I have some problem with customer engineers about SC current level on MV side of railway substation.
It is existing substation, where I have to calculate relay protections settings and to set-up relays.
Scheme is following:
Busbar 110 kV, 3-phase SC current 16.3 kA (3420...
In a current project I have several relay protections MiCOM P141 and other from the Px4x-series connected to Substation Automation System via IEC 60870-5-103 protocol. According to the relay manual it is possible to synchronize relay's real time clock in various ways, like via opto-input, via...
Yesterday I examined design drawings of 33 kV cable grid for a windfarm. I found that grounding wire along the complete cable routes is provided. Wire is 70 sq.mm bare copper, installed in the trench close to the cables. When more that one MV cables are in parallel in one trench separate ground...
In our current project we have 33 kV grid of wind farm with 33 kV earthed via earthing transformer and neutral earthing resistor in step-up (33/110 kV) substation. I am working now on the model of the grid for short circuit currents calcualtion and relay protection coordination.
In the software...
Last month we made relay protections maintenance tests on old power station. First unit have been energized in 1949 and worked until 1970-ies. But 6 kV switchgear delivered with this unit is still in operation! Switchgear is manufactured by Metrpolitan Vickers in 1944.
Attached is small archive...
For a current project I have to calculate short circuit currents of small wind park. Wind generators supplier is still not chosen, so owner of the park cannot give me exact data. But generally WG's will be 2,5 MW, converter type, probably from Vestas or Nordex.
For the purposes of short circuit...
I try modelling 20 kV grid of windfarm using ETAP. One of known problems is that when all generators are off grid generates back to National Grid reactive power which must be compensated.
My model consists of about 24 km 20 kV cables, 3x185 sq.mm. Rule of thumb is that such cable generates...
For a coming project in country of EU main contractor asked us whether we have "International legal capacity in investment design". We have several engineers with full legal capacity for our country (national equivalent of PE in US), but for first time we hear about such international status...
We have to test contact resistance of busbar joints of newly installed 400 kV switchyard. My problem is that I have no idea what value will be considered as a good. Probably some standard exists (here is IEC world), but I haven't it. Colleagues told me that there is some "rule of thumb" that...
I have to buy some micro-ohmmeter for field testing of contact resistance of CB's, disconnector switches, busbar joints, etc.
I have a choice between instruments using high DC current and low DC current. Both types have sufficient resolution and accuracy, that with low DC (actually 2A)can be...
This year we won an order for maintenance testing of relay protections in old thermal power plant. Until test set works instead of me :-) making automatic test of distance relay I made walk in control room and found several relay panels with very old relay protections. I know almost any type...
For current project I have to solve a problem which I never faced before:
Project is for substation 20/110 kV for large (50 to 150 MW) photovoltaic power station. My problem is how such substation have to be coupled to the grid. If generators are conventional rotating machines it is clear. But...
For my current project I have to design closing of Circuit Breakers in 1,5 breakers scheme via check synchronizing relay. By reasons out of my responsibility it was chosen that conventional control scheme will be used - control switches, not bay controllers.
It was desided to use 7VE611 check...
In our current project we have to install separate disturbance recorders (SIMEAS R from Siemens). We are reading and re-reading table of ANSI-numbers, but cannot find any suitable. May be the reason is that these numbers are mostly provided for protection relays and functions.
I am looking for...
