Hi All,
bit of a how long is a piece of string question... but i have been tasked with looking into some gas engine generators and doing some preliminary stability studies to see what they are capable for in terms of motor starting etc.
In terms of project background, there are 2x 2MW sets...
Hi All,
I have what is hopefully a simple problem - but just having a bit of brain fog and cant see the way through it.
We have a 2MWe rated gas engine, which is driving a 2481kVA @0.8PF alternator set, equivalent to 1984.8kW (its IEC world so alternators are rated on kVA)
The alternator...
Hi All,
I have carried out various system studies over the years, and while I understand power system stability and the general concepts of exciters and governors, I lack much in depth knowledge of the specifics of them. So I have a few general questions, I was hoping people could help with...
Hi All,
i am trying to size some surge arresters for a buried 33kV underground cable system using the IEC 60071 and 60099 standards, and i am getting a little lost - can anyone help shed some light / check my working.
The system is a 33kV network, which is impedance earthed through zig/zag...
All,
I have an 11kV site that when in island mode has a handful of EDGs that run unearthed, with an 11kV system earth provided by a zig-zag grounding transformer. the grounding transformer is rated at 131A (142ohms) for 30s.
My understanding of these units is that the grounding transformer...
Hi All,
i have come across some Alstom METI relays installed in conjunction with the Alstom MCGG relays to give a directional control.
The METI's are set at PhA = +30deg, PhB =-45deg and PhC =+30deg. PhB being set as an earth fault.
My question is does this mean the PhA and PhC elements are...
Hi All,
I have a project where the existing transformer protection relays are old Reyrolle TJM10 induction disc relays.
My issue, is i have no idea how these work, and how to go about finding the existing settings and then changing them to something new.
Does anyone have any documentation for...
Hi All,
so i am doing an arc flash study to IEEE 1584 using ETAP, and have been working through the various calculations etc.. Most of the answers are fine, but a few results are high and i have various mitigation measures like ZSI and arc flash sensors to consider. I am at early concept stage...
Hi,
I am trying to understand how you can calculate a transformers inrush multiplier from its open circuit test data. The transformer in question are 2.2MVA, 33/0.44kV, Dyn11, z= 6% (IEC design)
I have seen a few test reports, and also EMTP-ATP where they seem to have taken the transformer...
Hi All,
I was having a quick look at a problem relating to a smallish distribution transformer inrush current, causing a large volt dip on a network voltage, and i'm not sure I believe the results i am getting. The scenario is fairly simple
Grid voltage = 11kV
Grid 3Ph short circuit level =...
