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!
Explain the Synchronous Machines?
A synchronous machine, unlike an induction (or asynchronous) machine, only develops torque at a fixed, so called, synchronous speed - ns which is related to the supply frequency f and the number of pole-pairs p as follows:
ns = 60 . f / p
The main application of a synchronous machine is as a generating device for the bulk conversion of mechanical energy (from a gas, steam or water turbine or a diesel engine) to electrical energy. It is therefore found in all types of power generating stations and also standby generating plants. In the case of a steam plant, the machine is often referred to as a turbo-generator, turbine generator or turbo-alternator. Electrical machines are in general reversible in nature meaning that they are capable of operating both as a motor and as a generator. In this sense, the synchronous machine is no exception. A good example of this are pumped-storage hydro-electric schemes such as the one at Dinorwig in North Wales comprising 6 x 315-MW synchronous machines which can be operated as generators or motors. Synchronous motors are more expensive to install than induction motors and are only found in relatively small numbers in industry where there is a requirement both for a constant-speed drive and the ability of reactive power control.
If inverter-fed they can be used in high-speed variable speed drives for traction applications. Small single-phase synchronous motors have been widely used to provide a timing mechanism for processes such as washing machine cycles. A permanent magnet synchronous machine, usually termed as a DC brushless machine, serves as a basis for numerous high performance servo applications for machine tools and industrial robots. The objective of this module is to look at synchronous machines as a central part of a power generation system. In this sense, the following sections will discuss only the fundamental theory of classical synchronous generators and not the machine operating characteristics in motoring mode.
Explain the term half duplex transmission. A half duplex channel can receive and send, but not at similar time. It's as a one-lane bridge where two-way traffic should give way
Q. Series generator having a combined armature and field resistance of 0.4? is running at 1000 r.p.m. and delivering 5.5kw at terminal voltage of 110 V. If the speed is raised to 1
What is I/O mapping? The assignment of addresses to various I/O devices in the memory chip is known as I/O mapping.
A battery having of 12 cells are divided in three group which each group having of four cells in series. The three groups are joined in parallel. The emf of every cell is 1.5V and
Question: (a) Consider the subsequent LC impedance function: (i) If the function is to be realised using the Foster I Form, evaluate the values of the different compon
Hysteresis loss least depends on (A) Frequency. (B) Magnetic field intensity. (C) Volume of the material. (D)Grain orientation of material.
A 100-kW, 230-V shunt generator has R a = 0.05 and R f = 57.5 . If the generator operates at rated voltage, calculate the induced voltage at (a) full load, and (b) one-half fu
Explain in detail the operation of 8255 in mode1 taking suitable example. In mode1, Ports A and B are programmed as input or output ports and Port C is used for handshaking.
Q. Discuss the closed-loop behavior? Consider an elementary feedback control system, as shown in Figure, with H = 1. The output variable c and the input e to the direct transmi
Use Thevenin's Theorem, find the current flow by resistor R=10Ω.
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: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd