DC Excitation Systems: Use DC generators to power the field windings of the synchronous machine. 2. AC Excitation Systems: Use AC generators with rotating or static rectifiers to power the generator field winding.
What is AC excitation and DC excitation?
The DC excitation system has two exciters – the main exciter and a pilot exciter. The exciter output is adjusted by an automatic voltage regulator (AVR) to control the voltage at the alternator output terminals. The current transformer input on the AVR ensures that the generator current is limited in the event of a fault.
What is DC excitation?
1) DC Excitation The DC current generated by the exciter as the shaft rotates is then passed through brushes and slip rings to the rotor windings. This excitation voltage is then controlled by varying the main exciter field current through a pilot exciter.
What is AC excitation?
The excitation system of an AC alternator refers to how the alternator’s voltage is initially built up when it is switched on and controlled during use. The excitation system is responsible for supplying the main rotor with the field current.
What is the purpose of DC excitation in an AC generator?
A generator has a prime mover such as a turbine or diesel generator. The excitation system generates the electromagnetic field in the rotor. The stator has the armature winding which has the induced electrical energy. The stronger the generated magnetic field, the greater the electrical power generated.
What is AC excitation?
The excitation system of an AC alternator refers to how the alternator’s voltage is initially built up when it is switched on and controlled during use. The excitation system is responsible for providing field current to the main rotor
What is DC excitation?
1) DC Excitation The DC current generated by the exciter as the shaft rotates is then passed through brushes and slip rings to the rotor windings. This excitation voltage is then controlled by varying the main excitation field current through pilot excitation
Why is DC excitation used instead of AC excitation?
In the alternator, when the rotor conductor changes position as the rotor rotates, a constant flux must be generated in the rotor winding, and this is only possible when direct current is supplied to the winding of the rotor. …Since we need constant flux, direct current is used instead of alternating current to excite the synchronous generator
What is a DC excitation system?
What is an arousal system? Definition: The system that supplies direct current to the field winding of the synchronous machine to perform the protection and control functions of the power system. This system consists of an exciter, a PSS (Power System Stabilizer), an AVR (Automatic Voltage Regulator), a processing unit and measuring elements.
What is excitation in a DC motor?
The magnetic flux in a DC machine is generated by current-carrying field coils. The creation of magnetic flux in the device by causing a current to flow through the field winding is called excitation.
What is DC excitation in a synchronous motor?
Its armature winding receives a three-phase AC power supply, and the rotor winding receives a DC power supply. The excitation of a synchronous motor refers to the DC power supplied to the rotor, which is used to create the required magnetic flux