Measurement of Reactive Volt- AMPERES For the measurement of reactive power in a single-phase circuit we used compensated wattmeter. In compensated wattmeter the voltage applied to the pressure coil is 90° out of phase with the actual voltage and the wattmeter will read the reactive power VI cos(90° – Φ) i.e VI sinΦ.In single-phase measurement the … Read more
Two Wattmeter Method Two wattmeter method is generally used for measurement of power in 3-phase,3 wire load circuits.The current coils of two wattmeters are inserted in any two lines and pressure coil is connected from its own current coil to the line without a current coil. Let V1,V2,V3 and I1,I2,I3 be the voltages and currents … Read more
Measurement of Three Phase power:Three wattmeter method Wattmeter is a devices in AC circuit used for power measurement. Wattmeter is a devices which consists of two coils called Current coil(CC) and pressure coil (PC).Current coil is a low resistance coil which is inserted in series with line carrying current to be measured and pressure coil … Read more
Magnetic circuits Definition The closed path followed by the magnetic flux is magnetic circuit.All electric power machinery such as generator,transformer,motors depend for their operation on the magnetic circuits. A magnetic circuit consists of a structure composed for the most of high permeability magnetic material.The core is assumed to be composed of magnetic material whose permeability … Read more
Three phase Induction motor working Principle In DC Motors current is drawn from the supply and conducted into the armature conductors through the brushes and commutator. When the armature conductors carry current in the magnetic field established by the field, a force is exerted on the conductors which tends to move them at right angles … Read more
Three phase Induction motor Three phase induction motor are simple in construction as compared to DC Motorsor synchronous motor. They are widely used in electric motors in industry. The several features of induction motors are: A laminated stator core carrying a polyphase winding. A laminated rotor core carrying either a cage or polyphase winding, the … Read more