In an alternator, the initial excitation current from the battery is supplied to the rotor windings. This current creates a magnetic field necessary for the alternator to generate electricity. Once the rotor spins, it induces a current in the stator windings, which produces alternating current (AC) output. The excitation system may then adjust the current to maintain the desired output voltage.
In an alternator, the load current is supplied by the stator and the excitation is applied to the rotor. When the power factor is low (lagging), more excitation is required to maintain rated output voltage at rated current. More excitation is also required to maintain rated output voltage with increased output current. Increased excitation current means increased rotor losses that must be dissipated as heat. (akash)
formals to calculate exciation voltage of alternator
excitation voltage is sinusoidal because it is taken from the terminal of alternator but excitation current is non-sinusoidal because it always dc.
The third wire is for whats called the sensing or pre-excitation circuit. This wire supplies the initial current from the battery to the alternator's field coil that starts the buildup of the magnetic field that allows the alternator to start producing current.
No. The power to illuminate the Daytime Running Lights (DRL's) is supplied by the alternator, and does not have to be supplied by the battery. Once a vehicle is started and the engine is running you could remove the battery from the car entirely and everything requiring current would still operate.
The excitation current is provided by a small self-excited pilot generator, attached to the same shaft as the alternator's rotor.
The output voltage of an alternator is regulated primarily through a device called a voltage regulator. This regulator monitors the output voltage and adjusts the excitation current supplied to the rotor windings, ensuring that the output voltage remains within a specified range. By increasing or decreasing the excitation current, the regulator can control the magnetic field strength, thus stabilizing the alternator's voltage output under varying load conditions. Additionally, some systems use feedback mechanisms to maintain consistent voltage levels despite fluctuations in demand.
Alternator and battery
The current through the battery is the flow of electric charge, measured in amperes (A), that is being supplied by the battery at a given moment.
The function of a regulator in an alternator is to maintain a consistent output voltage by controlling the amount of current supplied to the rotor's field winding. It adjusts the excitation level based on the electrical load and the output voltage, ensuring stable performance and protecting the electrical system from overvoltage or under-voltage conditions. By doing so, the regulator enhances the alternator's efficiency and reliability in supplying power.
In general terms, 'excitation' simply describes the process by which an electric current produces a magnetic field. But, more specifically, it refers to the creation of the magnetic field by the field windings of a motor or generator. In the case of an alternator, for example, the armature windings (the windings into which voltages are induced) are stationary, and inserted into slots cut into the inner face of the stator. The field is then provided by the rotor which is supplied (via slip rings) with a 'excitation' current provided by an external d.c. voltage.
In and of itself, there is no current in a spark plug. Once a current is supplied, from an ignition coil (via a points distributer), or from a solid state ignition system (directed by a crank shaft sensor) a special ignition grade wire carries the current to the electrode of the spark plug. The primary current for the procedure to take place is supplied by the alternator when the engine is running, or by the battery when the engine is being started.