Rotor winding inter-turn short circuit fault is a common defect of generators. In case of a slight inter-turn short circuit, the unit can only continue to operate, but attention should be paid to strengthening monitoring and testing; when the inter-turn short circuit is severe, the rotor current will increase significantly and the temperature of the rotor winding will increase, limiting the reactive power output of the generator. , or make the unit vibrate more, or even force it to shut down. Therefore, when an inter-turn short circuit fault occurs in the rotor winding, the inter-turn short circuit point must be found through testing and eliminated to restore the generator to normal operation. The generator rotor is grounded at one point and two points. In addition, the rotor layer will also be grounded. and inter-turn short circuit fault. Rotor grounding can be divided into instantaneous grounding, intermittent grounding, and permanent grounding. It can also be divided into internal grounding and external grounding, metallic grounding, and resistive grounding. The staff was working on the excitation circuit, and the rotor was grounded due to accidental touching or other reasons.
Rotor slip ring insulation damage, rotor slot insulation damage, rotor slot insulation and end insulation damage, rotor lead insulation damage, etc. cause grounding. Insulation aging due to long-term operation, debris or vibration causing the insulating pads between some turns of the rotor to shift, partially blocking the rotor ventilation holes, causing local overheating and aging of the rotor winding insulation, causing the rotor to ground. Rats and other small animals enter the excitation circuit, the insulated water pipe on the stator's water inlet and outlet is broken and leaks, and the excitation circuit is dirty, causing the rotor to be grounded. When the rotor circuit is grounded at one point, no current loop is formed due to the grounding at one point, and no current passes through the fault point. The excitation system remains in a normal state and does not affect the normal operation of the unit. See if the rotor ground signal can be reset. If it can be reset, it is instantaneously grounded. If it cannot be reset, use a multimeter to measure the voltage of the positive and negative poles of the rotor to ground. If it is found that the voltage of one pole to ground drops to zero, the voltage of the other pole to ground rises. to full voltage, indicating that a little grounding has indeed occurred. How to handle the rotor grounding: Check whether anyone is working in the excitation circuit. If it is caused by a staff member, it should be corrected. Check whether there is any obvious damage to each part of the excitation circuit or whether it is grounded due to dirt. If the grounding is due to dirt, it should be purged and the relevant circuit should be inspected in detail. If necessary, the rectifier cabinet should be stopped in turn to determine whether it is caused by the grounding of the DC circuit of the rectifier cabinet. Check to distinguish whether the grounding is in the excitation circuit or the measurement protection circuit. If the rotor is grounded to a stable metallic ground at one point, and the fault point cannot be identified, in addition to strengthening monitoring of the unit operation, after obtaining dispatch consent, apply two-point grounding protection to the rotor. Trip and apply for shutdown processing as soon as possible.
What are the components of a generator?
Principle of power generation
Convert the kinetic energy of the wind into mechanical kinetic energy, and then convert the mechanical energy into electrical kinetic energy. This is wind power generation. The principle of wind power generation is to use wind power to drive the windmill blades to rotate, and then use a speed increaser to increase the speed of rotation to prompt the generator to generate electricity.
According to current windmill technology, power generation can begin at a breeze speed of approximately three meters per second (the degree of breeze). Wind power is becoming a craze around the world because it does not require the use of fuel and does not produce radiation or air pollution.
Due to the unstable air volume, the wind turbine outputs alternating current of 13 to 25V, which must be rectified by the charger and then the battery is charged, so that the electrical energy generated by the wind turbine is converted into chemical energy. Then use an inverter power supply with a protection circuit to convert the chemical energy in the battery into AC 220V mains power to ensure stable use.
Extended information:
1. Horizontal axis wind turbine, the rotation axis of the wind wheel is parallel to the wind direction;
2. Vertical axis wind turbine, the rotation of the wind wheel The axis is perpendicular to the ground or the direction of airflow.
Advantages:
1. Clean and good environmental benefits;
2. Renewable and never exhausted;
3. Infrastructure The cycle is short and can be constructed on land or at sea;
4. The installed capacity is flexible and the operation and maintenance costs are low.
Baidu Encyclopedia - Wind Power
Generators are usually composed of stators, rotors, end covers, bearings and other components.
The stator consists of the stator core, wire windings, machine base and other structural parts that fix these parts.
The rotor is composed of rotor core (or magnetic pole, magnetic yoke) winding, retaining ring, center ring, slip ring, fan and rotating shaft.
There are many types of generators. In terms of energy, they are divided into thermal generators, hydraulic generators, etc.; 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.
The working principle is that 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 motion of cutting the magnetic lines of force, thus generating an induced electric potential, which passes through the terminals. When it is drawn out and connected in the loop, a current is generated.