Tweet
By the way, even in the Britannica the principle by which an EMF is induced in the conductor of a synchronous generator with closed magnetic fields is not indicated; there is only a statement of the result.
Electric generator | Types, Uses & Advantages | Britannica
I made my own drawing which is exactly consistent with the maximum EMF with a three-phase winding and an implicitly polar magnetic rotor.
480452977_9226741477409199_1244883750594752467_n.jpg?_nc_cat=103&ccb=1-7&_nc_sid=bd9a62&_nc_ohc=4C5fZtzzN8oQ7kNvgH9qPo4&_nc_zt=23&_nc_ht=scontent-iad3-2.xx&_nc_gid=fZ79WcEDj4_MyBqCKKc-aw&oh=00_AYH7Pxe3WIHgknznnljXs5BA-BR_HpXctxTo calculate the maximum EMF in a three-phase generator, you need to use this position. By the way, one of my friends asked his acquaintances in Israel to perform a registration of the maximum EMF depending on the rotor position on very good equipment. Unfortunately, these results were not provided to me for review, although I was the initiator of such a study. They wanted to prove me wrong. I wonder why they refused?
Electric generator | Types, Uses & Advantages | Britannica
Rotor
elementary synchronous generator
An elementary synchronous generator is shown in cross section in Figure 2. The central shaft of the rotor is coupled to the mechanical prime mover. The magnetic field is produced by conductors, or coils, wound into slots cut in the surface of the cylindrical iron rotor. This set of coils, connected in series, is thus known as the field winding. The position of the field coils is such that the outwardly directed or radial component of the magnetic field produced in the air gap to the stator is approximately sinusoidally distributed around the periphery of the rotor. In Figure 2, the field density in the air gap is maximum outward at the top, maximum inward at the bottom, and zero at the two sides, approximating a sinusoidal distribution.
elementary synchronous generator
An elementary synchronous generator is shown in cross section in Figure 2. The central shaft of the rotor is coupled to the mechanical prime mover. The magnetic field is produced by conductors, or coils, wound into slots cut in the surface of the cylindrical iron rotor. This set of coils, connected in series, is thus known as the field winding. The position of the field coils is such that the outwardly directed or radial component of the magnetic field produced in the air gap to the stator is approximately sinusoidally distributed around the periphery of the rotor. In Figure 2, the field density in the air gap is maximum outward at the top, maximum inward at the bottom, and zero at the two sides, approximating a sinusoidal distribution.
Stator
The stator of the elementary generator in Figure 2 consists of a cylindrical ring made of iron to provide an easy path for the magnetic flux. In this case, the stator contains only one coil, the two sides being accommodated in slots in the iron and the ends being connected together by curved conductors around the stator periphery. The coil normally consists of a number of turns.
When the rotor is rotated, a voltage is induced in the stator coil. At any instant, the magnitude of the voltage is proportional to the rate at which the magnetic field encircled by the coil is changing with time—i.e.,the rate at which the magnetic field is passing the two sides of the coil. The voltage will therefore be maximum in one direction when the rotor has turned 90° from the position shown in Figure 2 and will be maximum in the opposite direction 180° later. The waveform of the voltage will be approximately of the sine form shown in Figure 1.
The stator of the elementary generator in Figure 2 consists of a cylindrical ring made of iron to provide an easy path for the magnetic flux. In this case, the stator contains only one coil, the two sides being accommodated in slots in the iron and the ends being connected together by curved conductors around the stator periphery. The coil normally consists of a number of turns.
When the rotor is rotated, a voltage is induced in the stator coil. At any instant, the magnitude of the voltage is proportional to the rate at which the magnetic field encircled by the coil is changing with time—i.e.,the rate at which the magnetic field is passing the two sides of the coil. The voltage will therefore be maximum in one direction when the rotor has turned 90° from the position shown in Figure 2 and will be maximum in the opposite direction 180° later. The waveform of the voltage will be approximately of the sine form shown in Figure 1.
I made my own drawing which is exactly consistent with the maximum EMF with a three-phase winding and an implicitly polar magnetic rotor.
480452977_9226741477409199_1244883750594752467_n.jpg?_nc_cat=103&ccb=1-7&_nc_sid=bd9a62&_nc_ohc=4C5fZtzzN8oQ7kNvgH9qPo4&_nc_zt=23&_nc_ht=scontent-iad3-2.xx&_nc_gid=fZ79WcEDj4_MyBqCKKc-aw&oh=00_AYH7Pxe3WIHgknznnljXs5BA-BR_HpXctxTo calculate the maximum EMF in a three-phase generator, you need to use this position. By the way, one of my friends asked his acquaintances in Israel to perform a registration of the maximum EMF depending on the rotor position on very good equipment. Unfortunately, these results were not provided to me for review, although I was the initiator of such a study. They wanted to prove me wrong. I wonder why they refused?
Comment