Common models of low-voltage capacitors

Low-voltage power capacitors are electrical devices installed in the power distribution system, used for reactive power compensation, improving power factor, reducing line losses and reducing the load of transformers. They are generally applicable to systems with a rated voltage of 1000V or below. So, what are the common models of low-voltage capacitors?

ⅰ. Why is reactive power compensation necessary?

In the power distribution system, inductive loads (such as motors and transformers) generate a large amount of reactive power, which leads to: a decrease in the power factor of the power grid; an increase in the burden on lines and transformers; an increase in electricity costs (if the power factor is below the specified level, a fine will be imposed); a decrease in system voltage, which affects the operation of equipment.

The low-voltage capacitor achieves an improvement in the system power factor by providing "capacitive reactive power" to balance with "inductive reactive power".

II. Common Models and Applications of Low-Voltage Capacitors

1. BSMJ (Dry Parallel Power Capacitor): The most commonly used, self-healing structure, small in size, generally used in industrial power distribution systems.

2. BKMJ (Metalized Film Capacitor): It has the most self-healing function and a long service life. It is used in industrial and mining enterprises as well as commercial buildings.

3. BAMJ (Safety Power Capacitor): Equipped with an internal overvoltage protection device, it is highly reliable and is suitable for use in places with strict safety requirements.

4. BCMJ (Cylindrical Parallel Capacitor): Cylindrical structure, facilitating the layout within the cabinet. It is commonly used in complete sets of power distribution cabinets and small-capacity distribution cabinets.

5. BBJM (Encapsulated Capacitor): Small-sized, integrated design, facilitating modular installation, suitable for low-power compensation and as an accessory for control cabinets.

6. FCKMJ (Filter-type Low-Voltage Capacitor): Equipped with an inductor, it can suppress harmonic interference and is suitable for use in places with frequency converters and rectification equipment.

III. Common Parameters of Low-Voltage Capacitors

Rated capacity: The reactive power output by a single capacitor (in units of Kvar).

2. Rated Voltage: The operating voltage of the capacitor (common values: 220V/380V/450V).

3. Frequency: 50Hz (industrial frequency).

4. Tolerance: Capacity tolerance, usually ranging from ±5% to +10%.

5. Insulation class: B class, F class, etc., which determines its temperature resistance capability.