Hello,
As a part of startup process, we did motor run but the speed is quite lower than the rated speed. Please refer to the following information.
Rating: 1.5HP, 3PH, 460V, 2.1A, 60Hz, 1760 RPM, SF=1.15
But motor running at 1558 rpm and 1.5Amp. So, I don't think it is overloaded at all. But...
Hello,
I will do commissioning tests for a plant synchronization system to control a group of turbine generators (2 ~ 3 generators together) to be synchronized onto the grid. FYI, GE CTG rating: 40 MW & Siemens STG rating: 82 MW. For our system, at least 1xCTG, and 1xSTG are to be controlled...
Hello,
Do you have any idea what if ANSI circuit breaker (60Hz) will be used on a 50Hz power system?
I guess manufacturer declared short circuit duties (ANSI, 60Hz) should be derated on a 50Hz power system. If so, do you have any reference materials on this issues? I tried to search IEEE papers...
Hello,
I have CT & PT designed for 60Hz system and tested per ANSI/IEEE standards but those will be used on 50Hz power system.
If so, are there any advices on this issues? I guess CT & PT burden should be derated accordingly and CT saturation will be faster than the same CT in 60Hz. Did I...
Hello,
I have a situation to install 4.16kV, 600kVAR capacitor on the three (3) existing 2500HP motors and all three (3) 2500HP motors on the same bus for power factor improvement. For self-excitation, 600kVAR is selected below 90% of motor no load current (106A) due to self-excitation issue...
We have total six (6) GTGs (all 15 MVA, 11kV generators) and all generators will be connected to a common 11kV bus. i.e. all generators in parallel and individually grounded. We have initially selected 100A NGR for each generator without neutral switching device.
In addition, we also have two...
Hello,
I have 14.24 MVA rated synchronous generator driven by gas turbine and it is rated at 42 degree C and all parameters are given based on this temperature.
If this generator will be running at 0 degree C. of site ambient temperature, the generator can cover more kVA e.g. let say 16 MVA as...
I have N+1 gas turbine generator configuration on my islanded system and 1 generator will be a running spare (i.e. on-line but No power generation – Client’s expectation). If one of running generators is tripped-off by a fault in this operating condition, a running spare will start providing...
Hello,
I am working on transient stability study for my project and I have a question on ISOCH & DROOP generator’s behavior when all these are running in parallel during fault condition.
When you open the attached file, you can see two graphs i.e. generators’ Pe & Pm during a fault and post...
Hello,
I have a trouble with my client due to the type transformer winding connections. Please refer to the following information and advise whether ungrounded primary wye-grounded secondary wye connection would not cause any problems.
1. Multiple synchronous Generators are all rated at 11kV...
Hello Folks,
I am wondering if there are any requirements on short circuit ratings of transformer's terminals.
I have 63kA rated 4.16kV switchgear considering parallel operation of two 13.8kV/4.16kV, 15MVA transformers with Z=6.0%.
Of course, 63kA rating is far exceeding SC curent feeding...
We are going to purchase the PF correction capacitor banks 13.8kV, 4800kVAR) with ungrounded wye configuration (single wye) with unbalanced voltage protection, and the system grounding is low impedance grounding (400A).
MY client have a concern that capacitive charging currents (circulating...
Hello,
Could you please advise whether there are any type tested Low voltage arc resistant motor control centers available in U.S. market?
It seems that LV MCC's has not been type tested yet since there is no standard applicable to LV MCC arc resistant design and just the manufacturer's...
Gents,
Typically, Inverter fed motors should have inverter duty not standard duty. However, motors for inverter service have alrealdy been purchased with NEMA standard duty not inverter duty.
So, I am looking for suppliers of LV VSD suitable for operating non-inverter duty motors.
Could you...
I need all of members' advices regarding oil sampling valve for transformer.
As far as I know, I think it is a different valve type from drain and filter valve with sampling device.
In addition, I think oil sampling valve is used for on-line oil sampling without de-energizing of transformer...
Hello,
As I understood, motor differential protection for VSD controlled motor will not be applicable due to constantly changing speed and load demands and it may be resulting in nuisance tripping of the relay.
Then, I wonder whether the differential protection (87T) can be applicable for VSD...
I need your advices on the subject.
As I know, buchholz relay is generally required for protection of conservator type transformer.
However, the client spec. requires buchholz relay for hermetically sealed type transformer as well.
I wonder whether it is excessive requirement or not.
If a...
Does anyone has the following documents relating to a fault current limiter?
1. T. Keders, "Aspects Concerning the Determination of the Operating Value in Applications of Is-Limiters"
2. T. Keders, "The Determinatino of the Setting Values of Protective Devices with di/dt Tripping in 3-Phase...
Hi!
I am really curious about a topic how nonliear loads such as large VSDs, arc furnaces, etc. would impact on power system stability especially for synchronous generator stability.
Sometimes, I have doubt whether it would be really concerned problems from the viewpoint of power system...
I need your advices on choosing programming languages for my study. Actually, I am going to study abroad to achieve MS degree on power engineering from coming fall semester.
Although I am an engineer, I don't have any experiences on any kinds of programming langauges. But, I think I need to...
