How to deal with sparking in generator carbon brushes
1. Check if the broom length is too short and reaches the lifeline, making the pressure too weak and the broom cannot contact the slip. ring;
4. Check the electrical resistance of the rotor to ensure that the resistance is normal and that there are no short circuits between turns
5. If the oil space in the bearing is too large, causing the brush on the slip ring to jump a lot when the rotor rotates, check whether the radial runout of the slip ring surface is too large. The brush bounces and sparks;
6. In addition, if the brush is consistent with the one used previously. The brush has requirements for conductive current and friction speed.
Methods to prevent sparking from generator carbon brushes: Check carbon brushes and carbon ringsreaders every day
1. The wear length of the carbon brushes should not exceed 2/3. When the wear length of the carbon brush exceeds 2/3 (that is, the top of the carbon brush and the top of the brush holder are on the same plane), it should be replaced.
2. There is no spark from the carbon brush. When the carbon brush just begins to spark, it is necessary to find the cause and eliminate it in time.
3. There is no deviation of the carbon brush from the outside of the slip ring, and there is no crack on the edge of the carbon brush.
4. The carbon brush braid is well connected to the brush holder and the carbon brush, and there is no heat or contact with the brush holder.
5. The carbon brush does not jump, shake or get stuck in the brush holder.
The carbon brushes and slip rings of the generatorare they the same thing?
Generators are generally composed of stators, rotors, end covers, bearings and other components.
The main function of the stator is to generate a rotating magnetic field.
The main function of the rotor is to be cut by the magnetic lines in the rotating magnetic field to generate (output) a current.
The stator consists of the stator core, wire windings, machine base and other structural parts that secure these parts.
The rotor is composed of a rotor core winding (or magnetic pole, magnetic yoke), retaining ring, center ring, slip ring, a fan and a rotating shaft.
The stator and rotor of the generator are connected and assembled by the bearings and end covers, so that the rotor can rotate in the stator and perform the line cutting movementnes of magnetic forces, thus generating an induced effect. electric potential, which is discharged through the terminals and connected to the circuit, an electric current is generated.
Detailed information:
Generator classification includes:
Generator points: DC generator and alternator ;
The alternator is divided into: synchronous generator and asynchronous generator (rarely used);
The alternator can also be divided intoFor single-phase generators and three-phase generators.
There are many types of generators. In principle, they are divided into synchronous generators, asynchronous generators, single-phase generators and three-phase generators. In terms of generation method, they are divided into steam turbine generators, hydraulic generators, diesel generators, gasoline generators, etc. In terms of energy,it is divided into thermal generators, hydraulic generators, etc.
References Baidu Encyclopedia - Generator
Baidu Encyclopedia - Stator
The role Generator Slip Rings
Carbon brushes and generator slip rings do not refer to the same thing.
As a sliding contact, carbon brushes are widely used in many electrical equipment. The product materials mainly include electrochemical graphite, grease-impregnated graphite and metal graphite (containing copper and silver).
Slip rings are electrical components responsible for connecting and transmitting energy and signals to rotating bodies. According to the transmission medium, slip rings are divided into electric slip rings, fluid slip rings and smooth slip rings, which can equalcollectively be referred to as “rotary connections” or “rotary connections”.
The slip ring is usually installed in the rotation center of the equipment and is mainly composed of two parts: rotating and fixed. The rotating part is connected to and rotates with the rotating structure of the device, called the "rotor", and the fixed part is connected to the energy source of the fixed structure of the device, called the "stator".
Detailed information:
1. From an intuitive point of view, the brush should be properly chamfered, with appropriate specifications, structural specifications, cross section and wire length meet the requirements. requirements, and there should be no loosening, falling or damage, falling edges, falling corners, tightening and other phenomena.
2. From a usage point of view, the priThe main signs of good brush performance are:
(1) Long life and no wear of the commutator or ring current collector.
(2) It has good switching and current collection performance, suppressing sparking within the allowed range and reducing energy loss.
(3) When the brush is running, it will not overheat, make much noise, or be damaged.
(4) During operation, a uniform, moderate and stable oxide film can quickly form on the surface of the collector or collector ring.
3. Test brushes using instruments. From a technical point of view, electric brushes must comply with national ministerial standards. The instrument can be used to test the performance of the brush according to the requirements of “Brush Technical Performance Table”. Such as brush resistivity, Rockwell hardness,volume density, current density, contact voltage drop, coefficient of friction, 50 hours of wear, permitted peripheral speed, unit pressure and even metal content, etc.
Baidu Encyclopedia - Carbon Brush
Emergency shutdown conditions of the generator
You must understand itTo understand their role, you must first understand the basic principles of electrical energy and kinetic energy conversion, that is, understand the principle of motors.
The principle of power generation: After the magnetic field cuts the wire, an electric current is generated in the wire. Generators cut wires by rotating a magnetic field. The rotating magnetic field is the rotor and the cut wire is the stator.
For the rotor to generate a magnetic field, a magnetic current must be entered into the rotor coil. It is used to send the strong magnetic currentgenerated by the exciter generator in the rotor coil.
Function:
To put it simply, since the rotor rotates, the excitation current is transmitted to the winding (excitation winding) of the rotor through the contact between the carbon brush and slip ring.
(1) Smoke or fire occurs in the generator or exciter, or a hydrogen explosion occurs in the generator.
(2) The main transformer and the high-power transformer have serious defects and need to be shut down urgently.
(3) The generator sealing oil is interrupted and cannot be restored quickly.
(4) A strong ring spark occurs in the slip ring of the generator or main exciter and cannot be eliminated.
(5) The generator vibrates strongly (far exceeding the specified allowable value).
(6) Lhe steam turbine tripped but the main generator circuit breaker did not trip.
(7) Other accidents endangering the safety of people and equipment occur.