The exhaustive list of topics in Electrical Machines in which we provide **Help with Homework Assignment** and **Help with Project** is as follows:

**Single phase transformers:**- Magnetic circuits, Ampere’s law, linear and nonlinear magnetic circuits; Faraday’s law of electromagnet induction.
- Concept of an ideal transformer, assumptions; ideal transformer at no load and on load, phasor diagram, voltage current and power relations; basic construction of a practical single phase transformer, conceptual differences with an ideal transformer.
- Constructional details of a practical single phase transformer, core, winding,insulation and cooling methods; circuit model of a practical transformer incorporating an ideal transformer.
- Analysis of a practical single phase transformer, exact and approximate equivalent circuits, phasor diagram, relation between referred variables and parameters, per unit system of representation.

**Testing and performance of single phase transformers:**- Experimental determination of single phase transformer equivalent circuit parameters, Open circuit and short circuit tests, per unit parameters; worked out example.
- Percentage regulation of a single phase transformer, phasor diagram, derivation, per unit representation; worked out example.
- Efficiency of a single phase transformer, maximum efficiency, all day efficiency; Sumpner’s test for experimental determination of a single phase transformer efficiency.

**Three phase transformers:**- Bank of three single phase transformers, voltage, current and kVA rating with different connections, open . connection; worked out example.
- Three phase transformer as a single unit; constructional features, three limb,five limb, core type and shell type constructions; comparison with bank of three single phase transformers.
- Three phase transformer connections, polarity and terminal convention,vector groups; Y/Y and ./. connections, connection and phasor diagram,per phase equivalent circuit based analysis.
- Y/.and ./Y connections. Connection and phasor diagrams, per phaseequivalent circuit based analysis; worked out examples.
- Y/Z and ./Z connections. Connection and phasor diagrams, voltage,current relations.

**Operation and performance of three phase transformers:**- Tap changing transformer.
- Parallel operation of single and three phase transformers, conditions and connection diagrams, per phase equivalent circuit based analysis with equal and unequal no load voltages, load sharing.
- Harmonics and switching transients in transformers, effect of transformer connections, inrush current.

**Special purpose transformers**.- Single and three phase three winding transformer, equivalent circuit, phasor diagram, tests.
- Single and three phase autotransformers, advantages, equivalent circuit and phasor diagram.
- Three phase to two phase conversion using Scott connection, connection and phasor diagram, analysis with balanced and unbalanced loads.

**Construction and operating principle of three phase induction machines:**- Basic constructional features of round rotor polyphase ac machines. Airgap mmf and flux waveforms due to single phase distributed winding.
- Airgap mmf and flux waveform in round rotor machines due to balanced three phase distributed winding excited by balanced three phase alternating current, rotating magnetic field.
- Generated voltage and torque expression in three phase round rotor ac machine with distributed winding.
- Construction and types of three phase induction machines, wound rotor and squirrel cage induction machines; representation of the squirrel cage by a balanced three phase winding.
- Basic operating principle, motoring and generating mode of operation, generated rotor voltage, synchronous speed, slip speed, per unit slip.

**Analysis of three phase induction machines:**- Exact and approximate per phase equivalent circuit; phasor diagram under no load and loaded condition.
- Power flow diagram in a three phase induction machine, airgap power, slip power, mechanical power; torque-slip and current-slip characteristics.
- Starting torque, breakdown slip, breakdown torque, maximum mechanical power, effect of equivalent circuit parameters.

**Testing of three phase induction machines:**- No load and blocked rotor tests for determining equivalent circuit parameters; losses and efficiency.
- Induction machine performance computation from circle diagram.
- Cogging torque and crawling; induction machines with deep bar and double cage rotors.

**Starting and speed control of three phase induction machines:**- Direct on line starting, stator resistance and reactance based starting, rotor resistance based starting.
- Y/. and auto transformer based starting; worked out examples.
- Speed control of induction motors by stator voltage variation and pole changing techniques.
- Variable frequency speed control of induction machines, v/f control method, slip power control method.