Hey Guys,
I am taking a deep dive into directional earth fault protection. I would like to know;if the relay is using Uo on the horizontal plane for polarizing the relay, does this means the internal calculation to determine the trip angle is a power calculation either reactive or active.
ROCOF on the main is used for anti-islanding protection to separate the plant from the main in the event the mains fail to prevent the generator from feeding out to the grid and creating its own island. Also, the relay signals the genset to switch modes from fixed kW mode to isochronous or droop...
@Waross, I understand that provision have to be made for adding and removing generator, but I was answering the question post by OP with 3 generator scenario. Also, in island mode with 3 generator more likely there will not be a dispatcher.
The term swing generator in island mode can operate in the following scenario:
Scenario #1 The swing generator speed governor is set to control the frequency in isochronous mode and AVR set to voltage control mode ( voltage droop control). The other two generator speed governor set to baseload...
What type of fuel injection system you have? EUI( electronic engine) or MUI (mechanical engine)? when you provide this information we can better assist you.
See attached a screen shot, of the different modes of operation, of the ABB unitrol AVR. In manual mode there is no limiter active.https://files.engineering.com/getfile.aspx?folder=bb918bad-e66b-411f-82cc-a094fcb599fc&file=unitrol.PNG
I believe this will depend on the AVR manufacturer. Most manufacturer will provide modes of operation and explain them in details.
I will take a look at ABB UNITROl 1020 manual and see what its says.
Waross,
When connected to a unstable national grid the genset should be in a fix KW mode. The turbine should not be reacting to grid disturbance (you can operate in droop if the grid is very stable) . If the grid do become unstable and out side the limits of the genset protection, the plant can...
When a droop generator is connect to unstable grid the droop when react with every frequency excursion the grid sees. This is inherent to droop mode of a governor. IF the grid frequency goes below 50(nominal) the Turbine will take on load and vise versa. the best operating mode for unstable grid...
WOW! Unitrol 1020 on a cat C27, I never saw that AVR used on a generator below 1MW.
There are certainly many ways to achieve speed and voltage biasing on a C27. Newer model caterpillar, with EMCP4.3 and 4.4, speed/ volt biasing can be done with digital or analog( 0-10V) input via the EMCP 4.3...
SIR is how the rotor will response to a change in frequency, because inertia is a resistance to change.
Although, SIR is important in the grid stability studies, the response of the generator during a frequency excursion is controlled by the governor. During a deviation from the nominal...
Two possible reason for this could be the hydro unit can only be operated in baseload or the unit can not carry the load by itself. it is too small.
Regards,
JS.
The fist approach for this is taking DG3 offline and check the offline voltage and compare this value with the data sheet. This voltage check should be done with a multimeter with a least 2 decimal place.
IF you can post a picture of the AVR and generator controller schematic.
Regards,
JS.
Basler offer one that use current transformers to booster the excitation during a fault or motor starting.See link below.
https://www.basler.com/Product/CBS-212A-Current-Boost-System.
ScottyUK,
Did you consider a excitation booster system? The module is power from the battery.Below is a link for one type.
http://www.kutai.com.tw/download/epmg1270epmg2470/epmg1270epmg2470-manual-en.pdf
"if a line-to-ground fault happens between the generator and its breaker while the generator is operating at full voltage and ungrounded, bad things are likely to happen - like your generator being damaged due to the high line-to-ground fault current that is likely close to a generator with low...
My two go too books are L.L.J Mahon's Diesel Generator Handbook and EGSA on-site power generation book (5th edition).Also Cummins and Woodward have lots of technical papers you will find useful. Woodward papers explain in detail the fundamental of governors operation (speed control, Baseload...
