- To provide knowledge and skill (to apply complex algebra) for the solution of AC circuits.
- To develop knowledge and skill on resonance by varying inductance, Capacitance and frequency.
- To develop concept on poly phase balanced power system.
- To acquire skill in measuring line and phase quantities in three phase supply.
- To assist in acquainting the concept of poly phase unbalanced power system.
- To develop the concept of non-sinusoidal waves.

**SHORT DESCRIPTION**

** **

Complex algebra − application to AC circuits; RLC Parallel circuits; Expression for power and VAR;series resonance; Parallel resonance ; Poly phase system – 3-phase interconnection; Star connected system; Delta connected system; Balanced Power System; Unbalanced power system; Non-sinusoidal waves.

**DETAIL DESCRIPTION**

** **

**Theory :**

** **

**Understand the application of complex algebra in RLC parallel circuit.**

1.1 Compute the value of parameters of RLC parallel circuit in

rectangular form of notation and polar form of notation.

1.2 Draw vector diagram of RLC parallel circuit.

1.3 Solve problems on RLC parallel circuit.

1.4 Solve problems on RLC series parallel AC circuit in rectangular

form of notation and polar form of notation.

1.5 Define admittance, susceptance and conductance.

1.6 Mention the units of admittance, susceptance and conductance.

1.7 Find the impedance, admittance, current and voltage in RLC parallel

circuit.

1.8 Draw impedance/admittance triangle of RLC parallel circuit.

1.9 Solve problems on series parallel AC circuit in rectangular form

of notation and polar form of notation.

** **

**Understand the concept of power calculation on AC circuit.**

2.1. Express the calculation of power employing complex form.

2.2. Calculate VAR employing complex form.

2.3. Explain the conjugate method of calculating real & reactive power.

2.4. Sketch wave diagram for power of different AC circuits.

** **

**Understand the principle of resonance in series circuit.**

3.1 State resonance.

3.2. State resonance in series circuit.

3.3. State various ways of securing resonance in series circuit.

3.4. Explain resonance with curve when varying frequency.

3.5. Determine resonance frequency in series circuit.

**Understand the effect of bandwidth and Q-factor in series resonance.**

4.1 Describe the resonant curve and bandwidth in series resonance.

4.2 Explain the effect of frequency upon reactance of the series resonance

circuit.

4.3 Show the graphical representation of series resonance.

4.4 Explain resonance with curve when varying inductance.

4.5 Explain resonance with curve when varying capacitance.

4.6 Define Q-factor of a series resonance circuit.

4.7 Solve problems related to series resonance.

4.8 List the applications of series resonance.

**Apply the principle of resonance in parallel circuit.**

5.1. State resonance in parallel circuit.

5.2. Describe the resonant curve and bandwidth in parallel resonance.

5.3. Determine the resonance frequency in parallel circuit with R-L and RC

branch.

5.4. State the condition for resonance in parallel circuit with L & R in one

branch and C only in other.

5.5. Show the graphical representation of parallel resonance.

**Understand the effect of bandwidth and Q-factor in parallel resonance.**

6.1 Define dynamic impedance and current magnification.

6.2 Describe the effect of Q-factor and bandwidth in parallel resonance

circuit.

6.3 List the applications of series and parallel resonance.

6.4 Express mathematical deduction of the exact and approximate

formula for parallel resonance.

6.5 Solve problems on parallel resonance.

6.6 Compare resonance in series circuit with that in parallel circuit.

**POLYPHASE SYSTEM**

** **

**Understand the concept of poly phase power system.**

** **7.1. Explain the term poly phase AC system.

7.2. List the advantages of poly phase power system over single-phase

power system.

7.3. State the generation of poly phase emf.

7.4. Sketch the wave diagram for a poly phase power system.

7.5. Draw vector diagram for a poly phase power system.

**Understand the concept of expressing poly phase power system.**

8.1. State the meaning of double subscript notation.

8.2. Identify the phase sequence of poly-phase system.

8.3. State the effects of reverse phase sequence.

8.4. Explain the methods of checking phase sequence.

8.5. Sketch the phase sequence diagram of 3-phase power system.

**Understand the concept of poly phase for interconnection.**

9.1. State possible ways of interconnection of 3-phase power system.

9.2. Sketch the circuit diagram of star connected 3-phase 3-wire system.

9.3. List the application of 3-phase 3-wire star connected power system.

9.4. Sketch the circuit diagram of 3-phase 4-wire star connected power

system.

9.5. List the application of 3-phase 4-wire star connected power system.

9.6. Draw the vector diagram of 3-phase 4-wire star connected power

system.

9.7. Express the relation between line and phase quantities of voltage and

current in a balanced 3-phase 3-wire star connected power system.

9.8. Simplify the relation between line and phase quantities of voltage and

current in a balanced 3-phase 4-wire star connected power system.

**Understand the concept of star connected power system.**

10.1. Identify neutral wire in a 3-phase star connected system.

10.2. Express the current in the neutral wire in an unbalanced 3-phase 4-

wire star connected system.

10.3. Draw the phasor diagram of 3-phase 4-wire star connected system.

10.4. Express the formulae IL = IP and VL = 3 Vp

10.5. Calculate volt-ampere, power and power factor in a balanced 3-phase

4-wire star connected power system.

10.6. Solve problems on star connected (balanced and unbalanced) power system.

**Understand the concept of delta connected power system.**

11.1. Sketch the circuit diagram of 3-phase delta connected power system.

11.2. Draw the vector diagram of a 3-phase delta connected power system.

11.3. Express the deduction of the formula VL = VP and IL = 3 IP for delta

connected power system.

11.4. Express the relation between line and phase current & voltage in a

delta connected power system.

11.5. Calculate the volt-ampere, power and power factor in a 3-phase delta

connected power system.

11.6. Solve problems on delta connected balanced power system.

11.7. Compare the advantages of star connected system with those of delta

connected power system.

**Understand the concept of unbalanced power system.**

12.1. State the meaning of unbalanced power system.

12.2. Explain Fortescue`s theorem.

12.3. Explain the positive sequence power system.

12.4. Explain the negative sequence power system.

12.5. Explain the zero sequence power system.

12.6. Explain the neutral current of unbalanced system.

12.7. Solve problems related to unbalanced system.

**NON-SINUSOIDAL WAVES**

** **

**13.Understand the principle of non sinusoidal waves.**

13.1 State non-sinusoidal waves.

13.2 Explain non-sinusoidal waves as the sum of sine and cosine waves

of different frequencies with graphical and mathematical representation.

13.3 State harmonics.

13.4 Explain harmonics in the **Y**-system.

13.5 Explain harmonics in the -system

**Understand power of non-sinusoidal waves.**

14.1 Calculate effective value of non-sinusoidal wave.

14.2 Explain power due to non-sinusoidal voltage and current.

14.3 Calculate volt-ampears due to non-sinusoidal voltage and current.

** **

**Understand power factor of non-sinusoidal waves.**

15.1** **Explain power factor due to non-sinusoidal waves.

15.2 Explain equivalent sine wave of non-sinusoidal wave.

15.3 Explain addition and subtraction of non-sinusoidal wave.

15.4 Solve problems related with non-sinusoidal wave.

** **

**Practical :**

** **

**Determine resonance frequency and draw resonance curve from RLC series circuit. by changing frequency , Inductance, Capacitance.**

1.1 Sketch the circuit diagram for RLC series resonance.

1.2 Select equipment, tools and materials for the experiment.

1.3 Connect the circuit according to the sketch.

1.4 Check all connection points before actual operation.

1.5 Record the readings from the meter applying power supply to the circuit.

1.6 Find the value of current, resistance, inductive reactance, capacitive reactance and impedance.

**Determine resonant frequency in RLC parallel circuit and draw of resonance curve.**

2.1 Sketch the circuit diagram for RLC parallel resonance.

2.2 Select equipment, tools and materials for the experiment.

2.3 Connect the circuit according to the sketch.

2.4 Check all connection points before actual operation.

2.5 Record the data from the meter applying power supply to the circuit.

2.6 Find current, resistance, inductive reactance, capacitive reactance and impedance.

2.7 Sketch the resonance curve with the frequency as abscise and current, resistance, inductive rectance, capacitive reactance and impedance as ordinate.

**Demonstrate poly-phase system and phase sequence.**

3.1 Sketch the circuit diagram of poly-phase system and phase sequence.

3.2 Select equipment, tools and materials for the experiment.

3.3 Switch on the poly-phase system of your laboratory.

3.4 Measure the phase voltages by voltmeter.

3.5 Observe the phase voltages by oscilloscope.

3.6 Compute phase sequence.

3.7 Note down the observations.

**Measure line and phase voltage & current in 3-phase star connected inductive load.**

4.1 Sketch the circuit diagram for 3-phase star connected load.

4.2 Select the tools, instrument and materials required for the experiment.

4.3 Connect the circuit according to the circuit diagram.

4.4 Check all connection points before connecting the power supply to the

circuit.

4.5 Record the readings of the instruments.

4.6 Compare the recorded values with calculated values.

4.7 Note down the observations.

**Measure line and phase current & voltage in 3-phase delta connected**

** inductive load.**

5.1 Sketch the circuit diagram for 3-phase delta connected load.

5.2 List the tools, instrument and materials required for the experiment.

5.3 Connect the circuit according to the circuit diagram.

5.4 Check all connection points before connecting the power supply to the

circuit.

5.5 Record the readings of instruments.

5.6 Compare the recorded values with calculated values.

5.7 Note down the observations.

**Construct vector diagram by measuring current, voltage and power in a**

** balanced 3-phase star connected inductive load.**

6.1 Sketch the circuit diagram for measuring power by 3-watt meters of a

3-phase star connected system.

6.2 Select equipment, tools and materials required for the experiment.

6.3 Connect the circuit according to the circuit diagram using proper equipment.

6.4 Check all connection points, equipment and instruments before actual operation.

6.5 Record the readings from the meters connected in the circuit.

6.6 Calculate the power from the formula

Pt = W1 + W2 + W3 and 3VpIp Cos θ

6.7 Draw the vector diagram using relevant data as obtained.

6.8 Note down the observations.

**Construct vector diagram by measuring current, voltage and power in a**

** balanced 3-phase delta connected inductive load.**

7.1 Sketch the circuit diagram for measuring power by 3-watt meter method in a 3-phase delta connected load.

7.2 Select equipment, tools and materials for the experiment.

7.3 Connect the circuit according to the circuit diagram.

7.4 Check all connections before actual operation.

7.5 Record the reading from the meters used in the circuit.

7.6 Calculate the power from the formula

Pt = W1 + W2 + W3 and Pt = 3 VLIL Cosθ

7.7 Draw the vector diagram using relevant data.

7.8 Note down the observations.

**Measure power and neutral current in a 3-phase, 4-wire unbalanced system.**

** **

8.1 Sketch the circuit diagram for measuring power and neutral current in 3-p hase 4-wire unbalanced load.

8.2 Select equipment, tools, instrument and materials for the experiment.

8.3 Construct the circuit according to the circuit diagram.

8.4 Check all connections & instruments before actual operation.

8.5 Record the readings from the meters used in the circuit.

8.6 Calculate the power and neutral current.

8.7 Calculate the phase angles.

8.8 Note down the observations.

**Measure line and phase voltage and current of a 3-phase star connected**

** capacitive load.**

9.1 Sketch the circuit diagram for measurement of line and phase voltage

and current of a 3-phase star connected capacitive load.

9.2 Select equipment, tools and materials required for the experiment.

9.3 Construct the circuit as per diagram with proper instrument.

9.4 Record the readings from the meters used in the circuit.

9.5 Calculate the line and phase voltage & current from the formula

IL = IP and VP =

9.6 Note down the observations.

** **

**Measure line and phase current and voltage in 3-phase delta connected**

** capacitive load.**

** **

10.1 Sketch the circuit diagram for measuring line and phase voltage and

current of a balanced 3-phase delta connected capacitive load.

10.2 Select tools, instruments and materials required for the experiment.

10.3 Build up the circuit according to the circuit diagram.

10.4 Record the readings from the meters.

10.5 Calculate the line and phase voltage and current from the formula

VL = VP and IL = 3 IP.

10.6 Note down the observations.

**11 Measure 3-phase power by 3-watt meter method in a balanced 3-phase**

** star connected capacitive load.**

11.1 Sketch the circuit diagram for measuring 3-phase power by 3-watt

meter method of a balanced 3-phase star connected capacitive load.

11.2 Select tools, instrument and materials required for the experiment.

11.3 Build up the circuit according to the circuit diagram.

11.4 Check all connections before actual operation.

11.5 Record the readings from the meters.

11.6 Calculate the power from the formula

Pt = W1 + W2 + W3 and Pt = 3 VLILCosθ

11.7 Draw the vector diagram using relevant data as obtained.

11.8 Note down the observations.

** **

**Measure 3-phase power by 3-watt meter method in a balanced 3-phase**

** delta connected capacitive load.**

** **12.1 Sketch the circuit diagram for measuring 3-phase power by 3-watt

meter method in a balanced 3-phase delta connected capacitive load.

12.2 Select equipment, tools and materials required for the experiment.

12.3 Connect the circuit according to the circuit diagram.

12.4 Check all connection points before connecting to the power supply.

12.5 Record the readings from the meters.

12.6 Calculate the power from the formula

Pt = W1 + W2 + W3 and Pt = 3 VLILCosθ

12.7 Draw the vector diagram using relevant data as obtained.

12.8 Note down the observations.

** **

**Perform star-delta conversion in a power system.**

13.1 Draw the circuit diagram of a balanced 3-phase star and delta

connection.

13.2 Select equipment, tools and materials for the experiment.

13.3 Build up the circuit for star connection.

13.4 Check all connection points before actual operation.

13.5 Record the readings form the meters connected in the circuit.

13.6 Calculate the equivalent values of impedance in delta connection.

13.7 Build up a circuit with equivalent values of impedance in delta connection.

13.8 Record the reading for delta connection.

13.9 Compare the result.

13.10 Note down the observations.

**REFERENCE BOOKS**

- A text book of Electrical Technology

– B. L Theraja.

- Introduction to Electrical Engineering

– V. K. Mehta.

- AC Circuit

– Corcoran.