Structure and working principle of generator

4.2Hydraulic generator

Hydropower generator set is also known as "water turbine generator set", the role is to rivers, lakes and other high water with potential energy to the low, by the turbine into the mechanical energy of the turbine, the turbine and then promote the generator to generate electricity, the mechanical energy into electrical energy. (e.g. Three Gorges in China).

How it works:

The energy conversion process of hydroelectric generating units is divided into two stages:

Firstly, the potential energy lost by water is converted into mechanical energy by water turbine, and then the mechanical energy of water turbine is converted into electrical energy by generator.

The specific process is as follows: under the impact of water flow, the turbine begins to rotate, converting the potential energy of water into mechanical energy; The turbine also drives the coaxially connected generator to rotate, under the action of the exciting current, the rotating rotor drives the exciting magnetic field to rotate, and the stator winding of the generator cuts the exciting magnetic force line in which the induced electromotive force is generated, and at the same time the output of electrical energy will produce an electromagnetic braking torque on the rotor in the opposite direction of its rotation. Since the water flow acts on the turbine continuously, the rotating torque obtained by the turbine from the water flow is used to overcome the electromagnetic braking torque generated on the motor rotor, when the two torques reach balance, the hydroelectric generator set will run at a constant speed, stably emit electricity, and achieve energy conversion. Therefore, the water turbine and the generator are the two most critical components of the hydroelectric generator set.

4.3Wind turbine

Wind turbines convert wind energy into mechanical work and drive the generator to generate electricity, which is a new type of power generation system with low price, reliable operation and no greenhouse gas emissions.

How it works:

The wind drives the windmill blades to rotate, and then the speed of rotation is increased through the speed reducer to promote the generator to generate electricity. According to current wind turbine technology, a breeze speed (the degree of breeze) of about three meters per second can start generating electricity.

4.4Automobile alternator

How it works:

The principle of current generation of alternator and DC generator is the same, both are "moving magnetic field magnetic field line" in "cutting" fixed wire, or "moving wire" in cutting fixed magnetic field magnetic field line, as long as the output current of the wire and the generator magnetic field relative motion, the generator can generate electricity. The relative motion here is achieved by dragging the rotating part of the generator (rotor) to rotate it, but the DC generator is rectified into direct current output by a device called the commutator (also called the commutator), and the alternator has no commutator and directly outputs alternating current.

4.5Three phase asynchronous generator structure diagram

Induction generator is also called "induction generator".

How it works:

An alternator in which a rotating magnetic field in the air gap between the stator and the rotor interacts with the induced current in the rotor winding. The steering of the rotor is the same as that of the rotating magnetic field, but the speed is slightly higher than the synchronous speed of the rotating magnetic field. Commonly used as a small power hydrogenerator.

4.6Diesel generator

Diesel generator set is an independent power generation equipment, refers to diesel fuel, diesel engine as the prime mover to drive the generator power machinery.

How it works:

In short, the diesel generator drives the generator.

In the cylinder, the clean air filtered by the air filter is fully mixed with the high-pressure atomized diesel oil sprayed out of the fuel nozzle. Under the upward extrusion of the piston, the volume shrinks and the temperature rises rapidly to reach the burning point of the diesel oil. Diesel is ignited, the mixture of gases burns violently, the volume expands rapidly, and the piston is pushed down, which is called "work". Each cylinder does work in a certain order, and the thrust acting on the piston becomes the force driving the crankshaft through the connecting rod, thus driving the crankshaft to rotate. The brushless synchronous alternator and diesel generator crankshaft are installed coaxial, you can use the rotation of the diesel generator to drive the rotor of the generator, using the principle of "electromagnetic induction", the generator will output induced electromotive force, and the closed load loop can produce current.

4.7Permanent magnet DC tachometer generator

Tachometer generator is a micro generator measuring speed, he converts the input mechanical speed into a voltage signal output, and requires the output voltage signal to be proportional to the speed. The principle will not be repeated.

V. Proportion of power generation energy