Recently I participated in a generator electrical test program. Measuring of Stator winding resistance is also of the mentioned tests.
One electromotor serviceman who worked in a small workshop needed an ac power supply with 100HZ frequency.
Mayor of a mathematical city promised that electrical energy will be free for their future citizen, because they will consume no energy for electrical power generation!!
In static excitation system (with brush)of large power plant generators
excitation voltage is supplied by 3-ph excitation transformer with typical vector group YD5 or DY5.
An industrial power system includes one gas turbine generator (6KV, 12 MW), a step up transformer (6/20 KV, Dyn11, 20 MVA) and relevant distribution system.
What is the purpose of Partial discharge measurement in generator? Pls.Explain with theroritical measurement principle.
i am working in a motion capture project one of its parts is a sensor
i need a formula of the voltage generated in the coil due to moving in electromagnetic Field from an inducer
is there any relation between speed of motor and power factor?
How do i design for a capacity of a Generator to be use in factory and bank?
Please explain about reacceleration scheme of motors.
Can I use 50HZ motor in 60HZ system and vice versa?
Whether can we start a synchronizing motor similar an induction motor?
What points shall be considered?
hi, i have a question that whether it is possible for an 3phase induction motor operating as synchronous motor.
When a generator is operating in parallel with another same size generator, what will be the effect of changing governor set points and field currents?
In power generation plant with several ungrounded generators and grounding only one generator, how can unearthed generator affecte from network earth faults?
Energy savings with lower frequency
We are consuming 50,000 Wh per day with 50 Hz 435 V , But when we reduce the frequency to 49 Hz , conumption will reduce to 2000 Wh
effect of increased voltage on motor
We have a generator feeding into an incomer, along a distance of about 15m. during ac pressure tests it was fine, all the phases and neutral were tied down to earth, and each one was tested individually.
I need three phase voltage, how can I obtain it? In my house we just access to one single phase counter as main power supply.
What will happen if we carry the generator tests at half of the rated condition?
It is well known that, if an Alternator is connected with Grid its (alternator) voltage can not be change and it follows the grid voltage but i've seen that when its excitation changes its voltage also changes, why?
What is run of new motor drive with VVVF drive? Is it compulsory for every new motor?
What are Park's equations and its benefits?
How much KW capacity of motor is required to produce 5560 m3/hr air, how it has to be calculated?
Is it possible to power supply of small power electromotor via usual electronic UPS?
how to run an induction motor as synchronous motor?
What would happen if I reverse the field current(excitation) of a three phase alternator?
Generally the field of the alternator is made the rotor.
Why is this done in this way?
Why shouldn't it be the other way?
What are the transient and sub transient concepts? Which phenomena cause transient and sub transient behavior of a generator in short circuit conditions?
In an alternator, why does the induced EMF lags the main field flux by 90°?
Why airgap flux can't change instantaneously in synchronous machine when short circuited?
Is the rule of thumb that the size of capacitor required for PFC of an induction motor is sq rt of 3 x line volts x no load current x 0.8 correct?...
Significance of shaft voltage/current in induction motors ...
In two-elevator buildings where lift wells are located side by side instead of two separate motors if we connect the two lift cars by a single rope and connect to a single motor and control by a single PLC can we save energy?...
What are the differences between NEMA and IEC/BS designs of induction motors?
What are the advantages/disadvantages of the two designs?...
What are the differences among variable speed,variable frequency and inverter drives? Can normal motors be used for above use?
Which voltage is better for a 1000kW motor? 3.3kV or 6.6kV or 11kV? What is the criteria of selection of voltage based on its kW rating for a motor? Please explain
I need to know a few thing about the speed torque curves of DC motors. Firstly, what's the formula of Stall torque and that of no-load speed of motor...?? ...
How to connect common mode voltage source of induction motor with bearing equivalent model for simulation studies and motor equivalent parameters.
The no load current of the induction motor should be less than 30% of rated load current. Is this a standard?...
What is synchronizing coefficient of synchronous machine? Its equation and conditions for stable and unstable system.
While the positive sequence reactance has different values during sub transient, transient and steady state periods, why these are not applicable for negative sequence reactance. Why there is no sub transient or transient negative sequence reactance?
I am having LAVT panel iwth 6.6KV/415V transformer connection in the panel i want to supply 200N to the AVR panel. I am having Yy11 vector group in LAVT panel and want know whether i should give ...
If we start a synchronous motor with field winding short circuited (no exitation) then we are sure that it will start as induction motor but, will this motor run as synchronous motor ??? or it will run as induction motor. pls explain in detail.
How much speed can be increased of a dc motor with the help of field control method?
what is the difference between distribution breaker & generator circuit breaker
100 HP motor is driven through variable frequency drives, capacitor is connected in secondary side of VFD. What are the problems that may arise?
What is the differance between electrical and machanical power? If you have a 550Kw gearbox do you need a 550Kw electric motor to turn it???
Why the variations of the air gap flux determine the transient characteristic of the short-circuit current? ...
what will happen if negative terminal of a device is connected to the earthen pot?
How should we proceed to size a large storage battery bank for solar power whose load contains different sizes of lamps,ac,motors etc
What is subtransient & transient reactances. how it is different than steady state reactances . and why low values will be prefered usually?
if suppose frequency is reduced in a transformer keeping the voltage as same the value of flux will decrease.What will its effect on performance of transformer as in comment about the new kva rating,variable and constant losses,magnetising current etc...!!
Why we use three phase transmission in present ,instead of 4 phase or above,why we are not use 4 phase and above....
Plzz explain technically concept means actual meaning in reality of active power,reactive power,and apparent power..
Plzzz explain the concept that....In d.c motor the resistance of outer cage is more as compare to inner cage,and the reactance of inner cage is more as compared to outer cage...
Why in AC sinsudial wave is come in function generator also,and why we use or draw sinsudial wave instead of square wave or ...
In a plant electric motors have not been tested regularly for some years, what tests shall be done to evaluate their conditions?
Why the synchronous generators connected in parallel in the network system have different power factor?
First of all, please accept my thanks for your great and valuable assistance.
To set function ANSI 49 for protection of electromotors, motor thermal time constant is needed which should be specified by motor manufacturer. ...