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# Power Engineering

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### Electrical Energy Conversion - Power

Please refer to the attached file.

### Electrical Energy Conversion - Rotation, Resistance and Speed

Please refer to the attached file. DC Machines A 300 hp, 500 V, 1750 rpm DC shunt motor, operating at rated conditions has an efficiency of 92.0 percent... (see attachment)

### Power Systems: Real Value of a Fault Current for 3-Phase Fault

Both machines in the attached diagram are rated at 50 MVA, 20 KV. The system base is the machines' base. Find the real value of the fault current for a 3-Phase fault at the motor terminals. See the attached file.

### Power Systems - Nodal Equations, Y Bus Matrix and P&Q

1. {See attachment for diagram and details}. All reactances are on the System's Base. Write the Nodal Equations and the YBus Matrix. 2. {See attachment for diagram and details}. Find P&Q delivered from the generator's terminals to the system.

### Power Systems Problem (3-Phase Fault; Matrices; Matrix Inversion)

For a 3-Phase fault at Bus 3, find (see attachment) the post fault bus voltages for each bus, and the currents to all busses. Show your work, including the Y & Z matrices. Explain your method of matrix inversion. **Please see attachment for complete question and diagram.

### Electrical Power Systems Problems

See the attached file. Electrical Power Systems Problems 1. A three-phase line serves a 54MW load with a .9 lagging power factor at a line voltage of 138KV. The line constants are: A = D = 1 at 0 degrees B = 85 ohms At 70 degrees C = 950 x 10^4 siemens at 90 degrees Find the line and phase values of voltage and current

### Power Electronics: A Single-Phase Bridge Rectifier

[11.13] A single-phase bridge rectifier has a purely resistive load R=10 Ohms, the peak supply voltage Vm=170 V, and the supply frequency f=60 Hz. Determine the average output voltage of the rectifier if the source inductance is negligible. Answers: a) Vd=120.13 V b) Vd=113.32 V c) Vd=150.42 V d) Vd=80.41 V

### [17.18] Power electronics

[Power electronics] The measured values of a diode at a temperature of 25 Degrees Celsius are: Vd=1V at Id=50A, Vd=1.5V at Id=600A. Determine (i) the emission coefficient n, and (ii) the leakage current. ============================================== Answers: a. (a) n=6, (b) Is=0.2A b. (i) n=5, (ii) Is=1A c. (i) n=8, (ii)

### Ladder Logic Timers

SEE ATTACHMENT: #4 and the Figure Above it. Questions: a.)What type of timer has been programmed? b.)What is the length of the time-delay period? c.)When does the timer start timing? d.)When is the reset? e.)When will rung 3 be true? f.)When will rung 5 be true? g.)When will output PL4 be energized? h.)Assume that

### Peak Value of Output Voltage and Voltage Gain of an Amplifier

A power amplifier when driven by a current source of 5mA rms and a source resistance of 8k, delivers 12.5W signal power to an 8 load resistance. Find peak to peak value of output voltage. If the input voltage to the amplifier shows 5 V rms, determine the voltage gain of the amplifier. The given multiple choice answer is verifi

### Power Amplifiers and RMS Value Calculations

A power amplifier when driven by a current source of 5mA rms and a source resistance of 8k, delivers 12.5 W signal power to an 8 load resistance. Find rms value of the output voltage. Show how you arrived at the answer. a) Vo rms = 15V or 10V or 20V or 5V

### Conservation of energy requires that the sum of the power absorbed by all the elements in a circuit be zero. The following Figure shows a circuit.

Conservation of energy requires that the sum of the power absorbed by all the elements in a circuit be zero. The following Figure shows a circuit. All of the element voltage and current are specified. Are these voltages and currents correct? Hint: Calculate the power absorbed by each element and add them up. Work out the

### Watts in Cassette Players

A walker's cassette tape player uses 4 AA batteries in series to provide 6V to the player circuit. The four alkaline battery cells store a total of 200 watts-second of energy. The cassette player is drawing a constant 10ma from the battery pack, what is the normal operating power of the cassette? a) 0.06W b) 0.6W c) 6W d)

### How long will the cassette tape player operate at normal power?

A walker's cassette tape player uses 4 AA batteries in series to provide 6V to the player circuit. The four alkaline battery cells store a total of 200 watts-second of energy. The cassette player is drawing a constant 10ma from the battery pack. How long will the cassette tape player operate at normal power? a) 8.3 x 10**

### Change of wired rifle microphones to a radio microphone system within a musical theatre

Please help me with this problem. If you can please supply any diagrams for this problem. The theatre's concerns when changing of wired rifle microphones to a radio microphone system are: on propagation related problems within the theatre and the positioning of transmit and receive antennas and "space diversity" reception.

### Risk Analysis and Management Fault tolerant systems Nuclear Power Plant Safety

2. A fault-tolerant nuclear reactor protection system consists of 3 processors and 6 memories. The system will fail if (a) any 2 of the 3 processors fail, or (b) any 2 of the 6 memories fail. The nominal failure rates of these processors and memories, provided by the manufacturers, are 1 per 10,000 hours and 1 per 2,000 hours

### Battery Charging

In order to charge a battery there must be a potential difference between the charger and the battery, i.e.a charging voltage. As a battery is being charged this potential difference reduces and since the charging current is related to this charging voltage the rate of charging also reduces. A battery is put on charge.The rel

### Determining average output voltage

A six phase star rectifier has a purely resistive load of R=10 ohms, the peak supply. Determine the average output voltage of the rectifier if the source inductance is negligible. Voltage Vm=170V, and the supply frequency 60 Hz. See the attached file.

### Parameters of a white Gaussian noise process

A white Gaussian noise process X(t) with power spectral density (PSD) N0/2=0.1 is input to an LTI filter with a transfer function H(f) given by H(f) = 2, |f| <= W and 0, otherwise The output is denoted Y(t). (1) Find the autocorrelation function RX(t) of X(t). (2) Find E[Y(t)]. (3) Find the PSD of Y(t). (4) De

### Power Electronics Engineering Details

Hi, I need assistance answering the following questions. Please open the attachment to see the problems, they are related to circuits.

### Power Electronics and Snuber Circuit

I need help breaking this problem down. We DO NOT use MATLAB or Spice. The JPEG shows the entire problem with the given sets. Can anyone show me the correct set?

### Design a half-wave unregulated power supply.

Design a half-wave unregulated power supply to give VL = 15V at IL = 10mA with deltav <= 0.1V. Assume a 120V, 60Hz supply. What is the regulation of the power supply?

### Inkjet Printer Power and Rating Problem

An A4 inkjet printer uses ink cartridges with a mass of 250g supported by a carrier having a mass of 150g. The printer head is moved across the page by a motor driving through a toothed belt. It makes a single traverse of the page in 1s, which includes acceleration and deceleration times. The acceleration and deceleration zones

### Finding the Capacitor Voltage

Problem also in attached file. The energy stored by a 1 mf capacitor used in a laser power supply is given as W=4e(-10t) J for T>=0. find the capacitor voltage at T=0.1 sec. A) 0.60V B) 1.5V C) 54.2V D) 89.4V

### The energy stored by a 1 mf capacitor.

Problem also in attached file. The energy stored by a 1 mf capacitor used in a laser power supply is given as W=4e(-10t) J for T>=0. what is the capacitor current at T=0.1s. A) -0.271 KA B) -0.271 A C) 0.271 A D) 1.472 A

### POWER SERIES SOLUTIONS

FIND POWER SERIES SOLUTIONS IN POWERS OF X OF THE D.E. y''-xy'+(3x-2)y=0 and FIND POWER SERIES SOLUTION OF EA. OF THE INITIAL-VALUE. y''+xy'-2y=0, y(0)=0, y'(0)=1 ON BOTH OF THE PROBLEMS I GOT STUCK ON THE RECURRENCE FORMULA AND GETTING POWERS OF X.