Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Parallel Operation of Interconnected Synchronous Generators
In order to assure continuity of the power supplywithin prescribed limits of frequency and voltage at all the load points scattered over the service area, it becomes necessary in any modern power system to operate several alternators in parallel, interconnected by various transmission lines, in a well-coordinated and optimized manner for the most economical operation. A generator can be paralleled with an infinite bus (or with another generator running at rated voltage and frequency supplying the load) by driving it at synchronous speed corresponding to the system frequency and adjusting its field excitation so that its terminal voltage equals that of the bus. If the frequency of the incoming machine is not exactly equal to that of the system, the phase relation between its voltage and the bus voltagewill vary at a frequency equal to the difference between the frequencies of the machine and the bus voltages. In normal practice, this difference can usually be made quite small, to a fraction of a hertz; in polyphase systems, it is essential that the same phase sequence be maintained on either side of the synchronizing switch. Thus, synchronizing requires the following conditions of the incoming machine:
• Correct phase sequence• Phase voltages in phase with those of the system• Frequency almost exactly equal to that of the system• Machine terminal voltage approximately equal to the system voltage
A synchroscope is used for indicating the appropriate moment for synchronization. After the machine has been synchronized and is part of the system, it can be made to take its share of the active and reactive power by appropriate adjustments of its prime-mover throttle and field rheo stat.
The system frequency and the division of active power among the generators are controlled by means of prime-mover throttles regulated by governors and automatic frequency regulators, whereas the terminal voltage and the reactive volt-ampere division among the generators are controlled by voltage regulators acting on the generator-field circuits and by transformers with automatic tap-changing devices.
Q. Why positive feedback is used in oscillator? The main application of positive feedback is in oscillators. An oscillator generates AC output signal without any input AC signa
Explain MMX Technology. Multimedia extensions technology adds 57 newly instructions to the instruction set of the Pentium - 4 microprocessors. The Multimedia extensions techno
conditional branch instruction
Role of Bureau of Energy Efficiency The role of the Bureau of Energy Efficiency is to: Ready standards and labels of appliances and equipment; Develop a list
varification of ohm''s law
A universal shift register can shift in both the left-to-right and right-to-left directions, and it has parallel-load capability. Draw a circuit for such a shift register.
Q. (a) Obtain a Thevenin equivalent circuit at terminals A-B in the circuit. (b) What impedance ¯ZL, when connected to A-B, produces maximum power in ¯ZL? (c) Find the val
can you let me know how much it would be for the answer to a question that has 2 parts
a) A 230 V/25V, 50 HZ transformer with a rated primary current of 1,2 Amps is used to supply a number of 25 V, 30 Watt halogen light bulbs. Assuming an ideal transformer and tha
Explain Dielectric constant. Dielectric constant: This is also termed as 'Permittivity'. All insulating material possesses an electrical capacitance. Such capacitance of unit d
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd