Capacitor is an electronic component that stores electric energy. It can accumulate and release electric energy in the circuit. The capacitor is composed of two metal sheets (electrodes) and the insulating material (dielectric) between them. When the voltage is applied at both ends of the capacitor, an equal amount of positive and negative charges will be accumulated on the electrode to generate an electric field, thus storing energy. The core functions of capacitor include energy storage, filtering, signal coupling and voltage stability.
The main function of capacitor is to store and release electric energy, which can provide a stable capacitance value in the circuit. In DC circuits, FDMS0312AS Capacitors can smooth current changes. In AC circuits, they can store and release electric energy and change the phase relationship of the circuit.
The basic unit of capacitance is Farad, and the commonly used units in practical applications are micro farad (μ F), nano farad (nF) and pi farad (pF). The capacitance value depends on the area of electrodes, the distance between electrodes, and the dielectric material.
The capacitor itself does not have low-voltage protection function. However, in power systems where capacitors are used, low-voltage protection mechanisms may be designed to meet the specific needs of capacitors or circuits. This protection is usually used to avoid automatically disconnecting or tripping the capacitor from the circuit when the grid voltage is lower than a certain set value because the capacitor cannot work normally or protect other sensitive parts in the circuit.
Low voltage protection is usually realized by low-voltage protection relay. When the grid voltage drops below the set threshold, the protection relay will act to disconnect the capacitor bank or related circuit through the control device, thus protecting the safe operation of the capacitor or circuit.
Then, why is the capacitor low-voltage protection triggered? The main reasons are as follows:
1. Grid voltage drop: when the grid voltage is lower than the rated voltage of the capacitor, the protection device will sense the voltage anomaly and start the protection action to protect the capacitor from low voltage.
2. Overload current: Overload exceeding the rated current of the capacitor may lead to voltage drop, thus triggering low-voltage protection action.
3. Poor contact of capacitor: if there are problems such as poor contact or loose wiring between the capacitor and the circuit, it may lead to voltage drop and trigger the low-voltage protection action of the protection device.
In order to prevent tripping caused by capacitor low-voltage protection action, the following solutions can be adopted:
1. Reasonable selection of capacitors: When designing the capacitor system, appropriate capacitors with rated voltage and capacity should be selected according to the actual needs to ensure that the system will not have low voltage during normal operation.
2. Increase the filter inductance: by adding appropriate filter inductance in the capacitor circuit, the current change rate in the capacitor circuit can be reduced and the possibility of capacitor voltage drop can be reduced.
3. Regular inspection and maintenance: regularly check the electrical connection and contact status in the capacitor system to ensure good contact between the capacitor and the circuit, and reduce the low-voltage problem caused by poor contact.
4. Parallel capacitor: multiple capacitors can be used for parallel connection to increase the total capacity and low-voltage resistance. When a capacitor is subject to low-voltage protection action, other capacitors can still provide the capacitor support required for continuous operation.
The above are some solutions to prevent tripping caused by capacitor low-voltage protection action. According to the actual situation and needs, appropriate methods can be selected to improve the stability and reliability of the capacitor system.
