A capacitor (Figure) is made of two conducting plates of area A capacitor (Figure) is made of two conducting plates of area A separated in air by a spacing x. The terminal voltage is v, and the charge on the plates is q. The capacitance C, defined as the ratio of charge to voltage, is […]
A four-pole, 60-Hz synchronous generator has a rotor length A four-pole, 60-Hz synchronous generator has a rotor length of 5.2 m, diameter of 1.24 m, and air-gap length of 5.9 cm. The rotor winding consists of a series connection of 63 turns per pole with a winding factor of kr = 0.91. The peak value […]
A A-connected, 25-kW, 230-V, three-phase, six-pole, and 50-Hz sq A A-connected, 25-kW, 230-V, three-phase, six-pole, and 50-Hz squirrel-cage induction motor has the following equivalent-circuit parameters in ohms per phase Y: R1 = 0.045 R2 = 0.054 X1 = 0.29 X2 = 0.28 Xm = 9.6 a. Calculate the starting current and torque for this motor […]
A common industrial application of dc series motors is in A common industrial application of dc series motors is in crane and hoist drives. This problem relates to the computation of selected motor performance characteristics for such a drive. The specific motor concerned is a series-wound, 230-V, totally-enclosed motor having a 1/2-hour crane rating of […]
Consider the single-phase induction motor of Example 9.5 operati In order to raise the starting torque, the single-phase induction motor of Problem 9.13 is to be converted to a capacitor-start, capacitor-run motor. Write a MATLAB script to find the minimum value of starting capacitance required to raise the starting torque to 0.5 N 路 m.
The voltage across a 100-uF capacitor is given by the The voltage across a 100-uF capacitor is given by the expression v(t)=120sin(377t) V. Find (a)the current in the capacitor and (b) the expression for the energy stored in the element.
The two capacitors shown in figure have been connected for some The two capacitors shown in figure have been connected for some time and have reached their present values. Determine the unknown capacitor Cs. a. 20µF b. 30µF c. 10µF d. 90µF
Data for the magnetization curve of the iron portion of Data for the magnetization curve of the iron portion of the magnetic circuit of the plunger actuator of Problem 3.12 are given below: a. Use the MATLAB poly fit function to obtain a 3’rd-order fit of reluctance and total flux versus mmf for the iron […]
Cylindrical iron-clad solenoid actuators of the form shown in fi The L/R time constant of the field winding of an 500-MVA synchronous generator is 4.8 s. At normal operating conditions, the field winding is known to be dissipating 1.3 MW. Calculate the corresponding magnetic stored energy.
Consider the two-phase motor of Example 9.3. a. Find the startin The equivalent-circuit parameters of an 8-kW, 230-V, 60-Hz, four-pole, two-phase, squirrel-cage induction motor in ohms per phase are Rl = 0.253 Xl = 1.14 Xm = 32.7 R2 = 0.446 X2 = 1.30. This motor is operated from an unbalanced two-phase, 60-Hz source whose […]