What are the hazards of a small thermal power plant generator with a higher reactive load than the a

Waste of resources. Impact on existing equipment.

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When the generator is active, there is no DU

The work automatically changes in the opposite direction, which can be explained by the DAO "version of the generator power angle characteristics".

The active power of the generator is proportional to sinδ, when the active power is increased to open the valve, the power angle of the generator δ increases, and the sinδ increases, but the reactive power of the generator is proportional to the cosδ, when the δ increases, the cosδ decreases, so the reactive power decreases.

When adjusting the reactive power, there is no effect on the δ of the work angle, so the active power will not change.

It can also be explained in terms of armature reactions.

It can be understood from the most basic law of conservation of energy! It should be added that the change in active power will cause the demagnetization reaction of the armature to increase or decrease, thus causing the reactive power change.

Hazards caused by low-load operation of diesel generator sets:

First, it often leads to poor piston-cylinder liner sealing, oil channeling, entering the combustion chamber for combustion, and exhaust smoke is emitted;

Second, for the supercharged diesel engine, the supercharging pressure is low due to low load and no load. It is easy to cause the sealing effect of the supercharger oil seal (non-contact) to decrease, and the oil will enter the pressurized chamber and enter the cylinder with the intake air.

Thirdly, part of the oil that goes up to the cylinder participates in the combustion, and part of the oil cannot be completely combusted, forming carbon deposits in the valves, intake tracts, piston tops, piston rings, etc., and some parts are discharged with the exhaust. In this way, oil will gradually accumulate in the exhaust tract of the cylinder liner, and carbon deposits will also be formed;

Fourth, the oil in the booster chamber of the supercharger accumulates to a certain extent, and it will leak out from the joint surface of the supercharger;

Fifth, it is also a very significant hazard that long-term low-load operation will lead to more serious consequences such as aggravated wear of moving parts and deterioration of the engine combustion environment.

Why increase the reactive power output of the generator during peak load? Because the so-called "peak load" means that the active power of electricity is at its peak, and the reactive power is usually at its peak at this time, so when the peak load is loaded, it is not only necessary to increase the active output of the generator, but also to increase the reactive power output of the generator according to the maximum reactive power demand.

Except for pure resistive loads such as incandescent lamps and heating rods, which do not involve reactive power, the general load is inductive, and the reactive power changes with the active power, but the impact on the power system is different.

The increase of load active power is manifested as a decrease in the frequency of the system, which is caused by the increase of the load resistance torque acting on the generator, after the automatic speed regulating device moves (or artificially) opens the large intake valve, the active torque acting on the generator shaft will reach a new balance with the load resistance torque.

The increase of load reactive power is manifested as a decrease in the system voltage, which is because the inductive current forms a demagnetizing effect on the generator magnetic field, which causes the generator stator induction potential to decrease, and the generator induced potential decreases, and the terminal voltage and the system voltage must decrease.

Of course, if the load only increases the active power and does not increase the reactive power (this extreme case is rare, but the disproportionate change of active and reactive power often occurs), then the system voltage change is very small, and there is basically no need to increase the reactive power output of the generator.

Many electrical equipment works according to the principle of electromagnetic induction, such as distribution transformers, motors, etc., which rely on the establishment of alternating magnetic fields to convert and transfer energy. The electrical power required to establish an alternating magnetic field and induced magnetic flux is called reactive power, therefore, the so-called"Reactive"Not really"Useless"'s electrical power, but its power is not converted into mechanical energy and thermal energy; Therefore, in addition to the active power supply, the reactive power supply is also needed in the power supply system, and both are indispensable. The unit of reactive power is var.

In the power triangle, the ratio of the active power p to the apparent power s is called the power factor cos, which is calculated as:

cosφ=p/s=p/（p2+q2）1/2

In the operation of the power grid, the power factor reflects the degree to which the apparent power output of the power supply is effectively used, and we hope that the greater the power factor, the better. In this way, the reactive power in the circuit can be minimized, and most of the apparent power will be used to supply the active power, thereby increasing the power of electric energy delivery.

The main factors that affect the power factor.

1) A large number of inductive equipment, such as asynchronous motors, induction furnaces, AC welding machines and other equipment are the main consumers of reactive power. According to relevant statistics, in all the reactive power consumed by industrial and mining enterprises, the reactive power consumption of asynchronous motors accounts for 60 70; And the reactive power consumed by the asynchronous motor when it is no-load accounts for 60 70 of the total reactive power consumption of the motor. Therefore, in order to improve the power factor of the asynchronous motor, it is necessary to prevent the no-load operation of the motor and increase the load factor as much as possible.

2) The reactive power consumed by the transformer is generally about 10 15 of its rated capacity, and its no-load reactive power is about 1 3 when it is fully loaded. Therefore, in order to improve the power factor of the power system and the enterprise, the transformer should not run at no load or be in a low-load operation state for a long time.

3) The power supply voltage exceeding the specified range will also have a great impact on the power factor.

When the power supply voltage is higher than the rated value of 10, due to the influence of magnetic circuit saturation, the reactive power will grow rapidly, according to the relevant statistics, when the power supply voltage is 110 of the rated value, the general reactive power will increase by about 35. When the supply voltage is lower than the rated value, the reactive power is also reduced accordingly, so that their power factor is increased. However, the reduction of the supply voltage will affect the normal operation of electrical equipment.

Therefore, measures should be taken to keep the supply voltage of the power system as stable as possible.

It doesn't matter if the generator load is low, the key is the economy of the prime mover.

When the engine is running under light load, it will cause the problem of carbon deposition and poor sealing, and the long-term low load will affect the life of the unit.

Diesel generator is a kind of small power generation equipment, which refers to the power machinery that uses diesel as fuel and diesel engine as the prime mover to drive the generator to generate electricity. The whole unit is generally composed of diesel engine, generator, control box, fuel tank, starting and control battery, protection device, emergency cabinet and other components.

You are an enterprise-owned power plant, and the "power plant" is equivalent to a step-down distribution room. Is the power plant in parallel capacitors on the 10kv bus?

The size of the compensation capacitor should be adjusted according to the size of the inductive load (motor), otherwise the voltage will inevitably be too high. The rated power factor of the generator is hysteresis), the voltage is high, the excitation current can only be reduced, so that the output reactive power is reduced, the power factor is several, and even the reactive power is reduced to zero and the voltage is still high. This situation has a great impact on the operational stability of the generator.

The correct way to do this is to reduce the number of compensation capacitors.

When the large motor is started, the inductive reactive power demand of the large motor exceeds the compensation capacity of the compensation capacitor, and the reactive power of the generator will increase significantly. Of course, it is normal for reactive power and active power to reach 1:1, mainly to control the voltage, and a little more reactive power for the generator, as long as the stator current and rotor current do not exceed the limit, there is no problem.

Let's be honest: I may not be able to answer your question, but I still hope you make it clear, how big is your generator set? how far it is sent to the production line; what lines; how big the load is on the production line; the range and frequency of fluctuations; How many power factors are there (rated, can't be adjusted, why?)

What is the meaning; Also, after starting the large motor on the production line, our reactive power is particularly high and cannot be adjusted? This high refers to the high reactive power or the high power factor; How big is your big motor and what is it for; Wait, as long as you can think of it, you can write it, when others help you analyze the problem, the more known conditions the better, some may be useless, but it is better than nothing.