capacitorbank

A capacitor bank is an assembly of capacitors connected in series and/or parallel to store electrical energy and provide reactive power in electrical power systems. By supplying or absorbing reactive power, capacitor banks help regulate voltage, reduce losses, and improve the system power factor.

A bank contains multiple capacitors housed together, with switchgear such as contactors or circuit breakers to connect or disconnect units. Detuning reactors may be included to limit harmonic resonance. Banks are built for low, medium, or high voltage and may be fixed or switched, either manually or automatically. Three-phase banks are typically arranged in star or delta configurations to match system voltage and required reactive power.

Fixed banks deliver a constant level of reactive power, while automatic banks are controlled by power factor controllers or energy management systems that adjust capacitance as load changes. In distribution networks they provide voltage support and can be paired with harmonic filters to mitigate distortion.

The primary use is power factor correction in industrial, commercial, and utility networks. Benefits include lower apparent power drawn from the grid, reduced energy penalties, and improved voltage profiles. Limitations include potential overvoltage at light load, possible resonance with system inductance, and generation of harmonics; proper protection and coordination are essential.

Maintenance and safety require regular inspection of capacitors and switchgear, thermal monitoring, and prompt replacement of failing units. Safe isolation procedures and adherence to manufacturer guidelines are essential during maintenance.