Induction Generators Driving an induction motor faster than synchronous speed when connected to the grid results in active power generation Induction generators (asynchronous generators) designed with lower rotor R to reduce losses and machine slip. Applications: Wind Turbines, Hydraulic Turbines (small scale hydro), Gas engines fueled by A synchronous generator's rotor consists of an electromagnet to which direct current is supplied. The rotor's magnetic field points in the direction the rotor is turned. Hence, the rate of rotation of the magnetic field in the machine is related to the stator electrical frequency by: 120 m e n P f 3. a a rms EE320 Homework # 9 Synchronous Machines SOLUTION Problem 1: A 4-pole, 60Hz, Y-connected, 3-phase generator has a regulated terminal line-to-neutral voltage of V as = 260V r ms ∠0, a synchronous reactance of 0.06Ω, a stator resistance of 0.003Ω, anLd sf = 0.02H .The balanced 3-phase load draws 2MW at a lagging 0.8 power factor. This experiment studies the characteristics of doubly-excited synchronous motors and generators. Specific tests are run to determine equivalent circuit parameters, torque, and power factor control. This lab shows that system design considerations must include frequency, speed, power factor, and voltage. (1) K factor = 1,00 for synchronous generators from 800 frame and above (2) K factor = 0,95 for synchronous generators from 800 frame and above (3) Counter pressure value is supplied at generator design stage. CUSTOMISED SOLUTIONS Among the large variety of options, systems and configurations available, Marelli Motori offer includes: Synchronous Generators • Generators are rarely used in isolated situations. More commonly, generators are used in parallel, often massively in parallel, such as in the power grid. The following steps must be adhered to: • when adding a generator to an existing power grid: 1) RMS line voltages of the two generators must be the same. A synchronous generator is a synchronous machine which converts mechanical power into AC electric power through the process of electromagnetic induction. Synchronous generators are also referred to as alternators or AC generators. The term "alternator" is used since it produces AC power. nent magnets in synchronous machines are restricted to those with ratings much lower than large turbine-driven generators, which is the subject of this book. Turbine-driven generators (for short: turbogenerators) take advantage of the fact that magnetic fields can be created by the flow of electric currents in conductors. See Figure 1.3. NS UNESCO - EOLSS SAMPLE CHAPTERS CONTROL SYSTEMS, ROBOTICS, AND AUTOMATION - Vol. XVIII - Control of Synchronous Generators - J. Hugel ©Encyclopedia of Life Support Systems (EOLSS) TO ACCESS ALL THE 10 PAGES OF THIS CHAPTER, Click here Bibliography A. J. Wood, B. F. Wollenberg (1984) Power Generation, Operation & Control John Wiley & Sons, New York [This book treats fundamentals of speed Synchronising Need to "synchronise" the generator to the gridbusbars. match the two systems in respect of phase sequence, voltage, frequency and phase. When all matched, close the circuit breaker(switch). Synchronised The two voltages V and E are then identical inmagnitude and angular frequency, , and theyare in-phase. IfV jXs EI = 0 Es V E Figure 3. Equivalent circuit of a synchronous generator [11]. Figure 4. Synchronous generator for different work regimes: a) unbiased generator, b) stand alone