How to discharge the three phase capacitor in the capacitor compensation cabinet?

In AC circuits, the phase characteristics of the voltage and current of resistors, inductors, and capacitive elements are that in pure resistive circuits, the current and voltage are in the same phase; In the pure capacitor circuit, the current leads the voltage by 90°; In a pure inductive circuit, the current lag voltage is 90°.

From the perspective of power supply, the ideal load is that p is equal to s and the power factor.

cos is 1. At this time, the utilization rate of the power supply equipment is the highest. In practice, this is not possible, and it is only possible to assume that the loads in the system are all resistive.

The nature of most of the electrical load equipment in the circuit is inductive, which causes the total current lag voltage of the system, so that in the power factor triangle, the reactive power Q side increases, the power factor decreases, and the efficiency of the power supply equipment decreases.

The power triangle is a right-angled triangle.

Use cos (i.e. cosine of the angle.

To reflect the quality of electricity, a large number of inductive loads make in the power system, from power generation to electricity equipment has not been fully used, a considerable part of the electric energy, through the generation, transmission, transformation, distribution system and user equipment between the exchange.

Reactive power is understood from another aspect.

Reactive power is not useless, it is necessary for the inductive device to establish a magnetic field.

Without reactive power, our transformers and motors cannot work properly. Therefore, it is the right solution to solve the problem of reducing reactive power.

Automatic discharge: When the contactor is disconnected, it is always closed and turned on two resistors of about 25w6k and the three ends of the capacitor are connected to discharge; If you want to manually discharge, you can use a small three-phase motor to connect with the three ends of the capacitor, or use two bulbs in series to connect a wire to the middle to the other two ends of the discharge, do not advocate direct discharge.

Because the capacitor used for compensation is constantly re-discharged, there is not much charge in the capacitor, and the discharge only needs to be used for each phase of the wire, and the right place is good.

Why does the distribution cabinet need to compensate for capacitance? What does capacitance compensation do? How to compensate?

Hello, I am happy to answer for you, after inquiring about the information, 1, capacitance compensation is reactive power compensation or power factor compensation, the electrical equipment of the power system will produce reactive power when in use, and it is usually inductive. It reduces the capacity efficiency of the power supply, which can be improved by increasing the capacitance appropriately in the system. 2. Capacitance compensation:

The capacitance of the distribution cabinet capacitance compensation and the load are connected in parallel, and the capacitance is the same as the power bank. When the load increases, the output voltage of the power supply decreases due to the internal resistance of the power supply. Because the two ends of the capacitor have to maintain the original voltage, that is, part of the electricity in the capacitor has to flow out, which delays the downward trend of the voltage.

3.Method: Parallel capacitors, generate capacitive current to offset the inductor current, and reduce the so-called reactive current that does not do work to a certain range.

Reactive power supply, like active power supply, is an indispensable part to ensure power quality, and reactive power balance should be maintained in the power system. Hope the above helped, thanks.

When the capacitance compensation capacitor of the distribution cabinet needs to be discharged, you can follow the following steps to operate Zhaopei: 1First of all, the power supply needs to be disconnected from the capacitor to avoid the risk of electric shock during the discharge process.

2.Then, using a special tool for discharge, it is necessary to connect it to both ends of the capacitor to ensure that the capacitor can be discharged quickly and completely. 3.

Next, you need to follow the instructions for using the tool, usually by inserting the tool into both ends of the capacitor for a few seconds until the capacitor is fully discharged. 4.Finally, confirm that the capacitor has been fully discharged before proceeding with other operations, such as service, replacement, or maintenance.

It should be noted that during the discharge process, it is necessary to pay attention to safety to avoid electric shock or other accidents. At the same time, it is also necessary to understand the specific parameters and characteristics of the capacitor before operation to ensure that the operation can be carried out correctly.

The discharge of the capacitor of the three-phase low-voltage compensation cabinet must be carried out in three processes:

First, the self-discharge process.

The capacitor in the event of a power failure is self-discharged between the two plates of the load. The self-discharge of the line compensation capacitor is to discharge the transformer installed on the line, and the time should be determined according to the capacity of the capacitor, which generally needs to be completed after 20 minutes of discharge process.

Second, the process of ground discharge.

After the self-discharge is completed, the ground discharge process can be carried out. The process of ground discharge is to repeatedly discharge each electrode of the capacitor to the ground pole by pole.

3. Direct discharge between electrodes.

After the ground discharge is completed, the capacitor has very little stored charge. In this case, the capacitor electrodes can be discharged directly, and it is now possible to confirm that the capacitor has been fully discharged.

1.It is carried out during non-peak hours to reduce the impact of reactive power loss of the line.

2.The first step is to turn off the controller of the compensation cabinet (if there is one), and then pull down the knife switch opening chain of the compensation cabinet.

3.Confirm the capacitor to be replaced, and discharge it reliably (ground discharge, three-phase short-circuit discharge is also acceptable).

4.Remove the capacitor to be replaced, reliably install the new capacitor of the same specification in the position of the original and old capacitor, and connect the wiring correctly (the new capacitor should be installed after testing it normally).

5.Close the knife switch of the compensation cabinet and open the controller of the compensation cabinet.

If there is a compensation cabinet controller, Li Xiaosun uses the self-test function of the controller to first carry out a self-test of the compensation cabinet, and then the replacement work is completed after the normal change, if it is manually compensated, then you can first carry out this capacitor"Prioritize investment"During the whole process, if any abnormalities are found, the compensation cabinet should be closed immediately for inspection and treatment. <>