electrical assignment

electrical circuit, need it in 30 hrs plz

Recognise a variety of complex waveforms and explain how they are produced from sinusoidal waveforms

1) The following waveforms can be constructed from a fundamental sine wave and some harmonics. Assuming a fundamental frequency 50Hz and a maximum value 100V.

a. State the complex equation for each waveform in the form:

v = DC + V1sin(t + ϴ1)+ V2sin(2t + ϴ2)+ V3sin(3t + ϴ3) + … Volts

b. Using a 10Ω resistive load, prove your equations by simulation.

(
Time
Volts
)

(
Time
Volts
)

(
Time
Volts
)

2) A complex voltage is determined by:

v = 120sint + 19sin(3t + 40) + 8.5sin(5t – 65) Volts

Where the frequency is 60Hz

Use Microsoft Excel (or something similar) to plot two complete cycles of the above waveform (show the fundamental and harmonic components as well as the overall waveform on the same graph).

Compare the complex waveform with the fundamental.

Task 2 – Learning Outcome 4.2

Apply AC theory to solve problems on R, L, C circuits and components

3) The circuit shown below is for a typical fluorescent lamp fitting, which is connected to a 230V 50Hz supply. Assuming the fluorescent tube has an operating resistance of 95Ω, calculate:

a. the impedance of the circuit

b. the current flowing through the tube

c. the power dissipated by the tube

d. the operating phase angle () of the complete fitting

e. the supply current to the fitting

(
L =
52
0mH
r = 1
4
Ω
C = 11
µF
Choke
Fluorescent Tube
Line
Neutral
)

4) The voltage of:

v = 115sint + 39sin(3t + 60) + 11.5sin(5t – 15) Volts

(Assume the frequency to be 50Hz) is applied to the terminals of the circuit below.

(
L = 85
mH
R = 47
Ω
C
Variable Capacitor
)

a. Find the value of the capacitor to make the above series circuit resonate at the third harmonic frequency.

b. Using the value of capacitance found in a) above, find an expression for the instantaneous current. In the form

i = If sin(t + ) + I3 sin(3t +) + I5 sin(5t + ) amps

c. Using the answer to b) above, find the RMS value of this current.

Task 3 – Learning Outcome 4.3

Apply AC theory to solve problems involving transformers

5) In the following ideal transformer a turns ratio of 12:1, calculate:

a. The load resistance value that will allow maximum power transfer.

b. The transformer primary input impedance (Zp)

c. The load voltage.

d. What will be the maximum power developed in the load?

(
230V RMS
1600
Ω
Variable Load
)

6) A 25 resistor is connected to the secondary winding of a ‘perfect’ single phase transformer. The terminal voltage at the secondary is 230V. If the Primary terminal voltage is 1000V, calculate:

a. The turns ratio.

b. The current I2 (A) and power P2 (W) drawn by the load.

c. The current drawn from the supply I1 (A).

d. State the losses found in a typical transformer.