0
Is this normal during a parallel of two generators where lead generator is higher in both load ampere and reactive power than the lag generator but with the same frequency same kilowatt load?
Wiki User
∙ 11y ago
No it is not normal.
Ideally both the generators share the load equally provided both generator ratings and other parameters are same.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
Why shaft generator can not operate in parallel with auxiliary generator?
Normal shaft generators do not have droop-control for frequency and voltage. Semiconductor (drive) based variable speed shaft generators may have those today.
How can the power output of generators be coupled?
Generally speaking, the outputs of generators can be coupled by connecting the generators in parallel. In generators that produce DC (direct current), the voltages need to be equalized and the polarities of the connections needs to be observed. Both negatives are connected together and both positives connected together to create one parallel output. In an AC setup, the generators need to be running about the same voltage, and must be connected in phase for the setup to be successful. In practice, the generator that is being brought online is run up, and it frequency is allow to be a little bit faster than the unit that is online. When the phase difference is being observed, and the difference is approaching zero, at a "couple of degrees before" the zero, the generator that is being brought online is then connected to the grid and it "locks in" so that all the generators are running in phase. Connecting DC generators positive to negative is an invitation to disaster, and bringing an AC generator online 180 degrees out of phase with an running generator is the same kind of disaster. Shutting a breaker to parallel generators without insuring polarity concordance (in the case of the DC ones) or phase concordance (in the case of the AC ones) will pit one generator against the other, and severe damage will result.
Can you combine two generators circuits together?
Proton LED engineer in Lyons GA says: the two circuits would have to be in phase in order to combine them. *Actually you can always combine generator circuits. The problem comes in with HOW in phase the circuits are. If the generators are in phase (0 degrees apart) their AC voltages and currents would combine completely, but if they are out of phase (90 degrees apart) the voltages and currents will appose each other to such an extent that they will basically cancel each other out. The trick is to apply some sort of phase correction to one of the circuits in order to modify the phase difference between the two so that you can get the desired power output. Just be careful not to exceed your rated line currents when combining two generator circuits, otherwise things could get smoky! - Tristan JvR
How do you synchronize 2 power generators?
generally the generators are synchrozised by checking three conditions 1. their terminal voltages must be the same 2.their frequencies must be same 3.their phase sequence must be same if any one of the conditions are not satisfied and they are connected in parallel then the machines will be burnt with in a fraction of second
What are the condition for parallel operation of the generators?
Parallel Operation of DC Generators: In a dc power plant, power is usually supplied from several generators of small ratings connected in parallel instead of from one large generator. This is due to the following reasons: (i) Continuity of service: If a single large generator is used in the power plant, then in case of its breakdown, the whole plant will be shut down. However, if power is supplied from a number of small units operating in parallel, then in case of failure of one unit, the continuity of supply can be maintained by other healthy units. (ii) Efficiency: Generators run most efficiently when loaded to their rated capacity. Therefore, when load demand on power plant decreases, one or more generators can be shut down and the remaining units can be efficiently loaded. (iii) Maintenance and repair: Generators generally require routinemaintenance and repair. Therefore, if generators are operated in parallel, the routine or emergency operations can be performed by isolating the affected generator while load is being supplied by other units. This leads to both safety and economy. (iv) Increasing plant capacity: In the modern world of increasing population, the use of electricity is continuously increasing. When added capacity is required, the new unit can be simply paralleled with the old units. (v) Non-availability of single large unit: In many situations, a single unit of desired large capacity may not be available. In that case a number of smaller units can be operated in parallel to meet the load requirement. Generally a single large unit is more expensive. Connecting Shunt Generators in Parallel: The generators in a power plant are connected in parallel through bus-bars. The bus-bars are heavy thick copper bars and they act as +ve and -ve terminals. The positive terminals of the generators are .connected to the +ve side of bus-bars and negative terminals to the negative side of bus-bars. Fig. (1) shows shunt generator 1 connected to the bus-bars and supplying load. When the load on the power plant increases beyond the capacity of this generator, the second shunt generator 2 is connected in parallel with the first to meet the increased load demand. The procedure for paralleling generator 2 with generator 1 is as under: (i) The prime mover of generator 2 is brought up to the rated speed. Now switch S4 in the field circuit of the generator 2 is closed. (ii) Next circuit breaker CB-2 is closed and the excitation of generator 2 is adjusted till it generates voltage equal to the bus-bars voltage. This is indicated by voltmeter V2. (iii) Now the generator 2 is ready to be paralleled with generator 1. The main switch S3 is closed, thus putting generator 2 in parallel with 51 generator 1. Note that generator 2 is not supplying any load because its generated emf is equal to bus-bars voltage. The generator is said to be "floating" (i.e. not supplying any load) on the bus-bars. Figure(1) (iv) If generator 2 is to deliver any current, then its generated voltage E should be greater than the bus-bars voltage V. In that case, current supplied by it is I = (E - V)/Ra where Ra is the resistance of the armature circuit. By increasing the field current (and hence induced emf E), the generator 2 can be made to supply proper amount of load. (v) The load may be shifted from one shunt generator to another merely by adjusting the field excitation. Thus if generator 1 is to be shut down, the whole load can be shifted onto generator 2 provided it has the capacity to supply that load. In that case, reduce the current supplied by generator 1 to zero (This will be indicated by ammeter A1) open C.B.-1 and then open the main switch S1. Load Sharing: The load sharing between shunt generators in parallel can be easily regulated because of their drooping characteristics. The load may be shifted from one generator to another merely by adjusting the field excitation. Let us discuss the load sharing of two generators which have unequal no-load voltages. Let E1, E2 = no-load voltages of the two generators R1, R2 = their armature resistances V = common terminal voltage (Bus-bars voltage). Then 1 1 1 R I E V   and 2 2 2 R I E V   Thus current output of the generators depends upon the values of E1 and E2. These values may be changed by field rheostats. The common terminal voltage (or bus-bars voltage) will depend upon (i) the emfs of individual generators and (ii) the total load current supplied. It is generally desired to keep the busbars voltage constant. This can be 52 achieved by adjusting the field excitations of the generators operating in parallel. Compound Generators in Parallel: Under-compounded generators also operate satisfactorily in parallel but over compounded generators will not operate satisfactorily unless their series fields are paralleled. This is achieved by connecting two negative brushes together as shown in Fig. (2) (i). The conductor used to connect these brushes is generally called equalizer bar. Suppose that an attempt is made to operate the two generators in parallel without an equalizer bar. If, for any reason, the current supplied by generator 1 increases slightly, the current in its series field will increase and raise the generated voltage. This will cause generator 1 to take more load. Since total load supplied to the system is constant, the current in generator 2 must decrease and as a result its series field is weakened. Since this effect is cumulative, the generator 1 will take the entire load and drive generator 2 as a motor. After machine 2 changes from a generator to a motor, the current in the shunt field will remain in the same direction, but the current in the armature and series field will reverse. Thus the magnetizing action, of the series field opposes that of the shunt field. As the current taken by the machine 2 increases, the demagnetizing action of series field becomes greater and the resultant field becomes weaker. The resultant field will finally become zero and at that time machine 2 will be short circuited machine 1, opening the breaker of either or both machines. Figure (2) When the equalizer bar is used, a stabilizing action exists and neither machine tends to take all the load. To consider this, suppose that current delivered by generator 1 increases. The increased current will not only pass through the series field of generator 1 but also through the equalizer bar and series field of generator 2. Therefore, the voltage of both the machines increases and the generator 2 will take a part of the load.
Why shaft generator can not operate in parallel with auxiliary generator?
Normal shaft generators do not have droop-control for frequency and voltage. Semiconductor (drive) based variable speed shaft generators may have those today.
What does Incoming and running generators are in same phase while paralleling two generators mean?
When two generators are to be run in parallel, one generator is first started and some load is given. Then second generator is brought in parallel with the running generator (subject few conditions, like voltage, frequency, phase angle). First generator which is running is known as running generator, the second generator which gets connected is known as incoming generator
How many generator we can operate in parallel in a system?
In a grid system all the alternators run in parallel, locked together in frequency.
How do you calculate voltage drop of the first generator when two generators are in series with a neutral?
Restate your question. Generators don't run in series. Generators always run on parallel synchronizing so your question is wrong.
What happen if a prime mover fails when two generators are in parallel?
It acts as synchronous motor by consuming power from the other generator....
What will happen if it does not met the parallel operation of a dc generator?
there will be circulating current between the generators sufficiently large that might damage the machines.
How can the power output of generators be coupled?
Generally speaking, the outputs of generators can be coupled by connecting the generators in parallel. In generators that produce DC (direct current), the voltages need to be equalized and the polarities of the connections needs to be observed. Both negatives are connected together and both positives connected together to create one parallel output. In an AC setup, the generators need to be running about the same voltage, and must be connected in phase for the setup to be successful. In practice, the generator that is being brought online is run up, and it frequency is allow to be a little bit faster than the unit that is online. When the phase difference is being observed, and the difference is approaching zero, at a "couple of degrees before" the zero, the generator that is being brought online is then connected to the grid and it "locks in" so that all the generators are running in phase. Connecting DC generators positive to negative is an invitation to disaster, and bringing an AC generator online 180 degrees out of phase with an running generator is the same kind of disaster. Shutting a breaker to parallel generators without insuring polarity concordance (in the case of the DC ones) or phase concordance (in the case of the AC ones) will pit one generator against the other, and severe damage will result.
What is a compound dc generator?
generators are machines that convert machanical energy to electrical energy and could be AC or DC. if in a DC generator has it field armature connection in both series and parallel its said to be compound dc generator.
What is a popular brand of portable power generator?
Two of the most popular generators are now available in this kit! The EU2000i and the EU2000i Companion contain 4000 watts of combined power. Take both generators to a job site, or a single generator to the beach. Double Your Power: Easily link two identical wattage EU generators in parallel Using the Honda Parallel Cables you get more power without sacrificing portability.
Is it feasible to parallel the dissimilar rating generators?
yes,but the two dismaler generators should have the following similarity; 1]same voltage rating 2]same frequency 3]same rpm.
Frequency voltage and amperage must be equal when ac generators are operated in parallel?
Frequency and voltage, yes. Amperage - desirable but not mandatory. Paralleled generators that are equally sized generally have a load balancing control that accomplishes this function. Generators that are of different ratings may be loaded to different current levels because of their capacity limitations.
Why load shedding panels are used in substation?
If you have many Gas turbine Generators working on parallel, if any fault happened in one generator ( so this generator is no longer feeding the load ) load shedding panels will disconnect a group of predetermined Less important loads to help the working generators in the additional load (which may come after fault of the mentioned generator ).
