The low voltage capacitor bank is an electrical device used for compensating low voltage power grids. It effectively improves the power factor of the power grid, enhances the stability of the power grid quality, and reduces line losses.
The low voltage capacitor bank consists of a control cabinet, capacitor, circuit breaker, fuse, current transformer, temperature protector, overvoltage protector, etc.
| Rated Voltage | 380V, 400V, 415V, etc. |
| Rated Frequency | 50Hz/60Hz |
| Rated Capacity | 10kvar~1200kvar |
| Capacitor Voltage | 250VAC~690VAC |
| Capacitor Working Temperature | -25℃~+55℃ |
| Control Voltage | AC220V, DC110V, etc. |
| Control Method | Manual/automatic control |
| Overvoltage Protection | 255V±5% |
| Overcurrent Protection | Set according to the rated capacity |
| Short-circuit Protection | 100kA |
| Insulation Resistance | ≥100MΩ |
| Enclosure Protection Level | IP30~IP54 |
| Dimensions | Customized according to customer requirements |
With the energy transition, good power quality is becoming increasingly important for utilities, industrial and commercial networks. The growth of renewable energy and the dominance of electronics in the industrial and consumer sectors have made the grid more susceptible and sensitive to harmonics, voltage variations, load imbalances, and low power factor disturbances.
These outages can result in reduced productivity, damage to equipment, financial loss, and penalties from utilities for not following grid codes. This article can help you understand the low-voltage capacitor bank, so let’s get started.
Capacitor banks have been a reliable solution for reducing reactive power for decades. Installing capacitor banks for power factor correction is worthwhile if your goal is to increase electrical installation efficiency or reduce costs. Power factor correction increases grid capacity while preventing excessive cable losses and associated costs.
In addition, it reduces CO2 emissions. Not only can this improve your company’s operating profit, but it’s also good for the environment. Low-voltage automatic capacitor banks improve power factors in systems with variable energy demands and non-linear loads. Automatic capacitor banks are equipped with power factor controllers to adjust their automatic operation and monitoring functions, eliminating power factor charges in electricity bills and reducing losses in electrical equipment and wiring.
The following are several classifications of capacitor banks:
Relay-controlled capacitor banks are the most common choice for reducing reactive power. These capacitor banks are suitable for various loads. Reaction times are slow, and there is always under-compensation or overcompensation. However, they are often the most cost-effective solution for small to medium installations.
An SCR-controlled capacitor bank works the same as a relay-controlled capacitor bank. However, SCR control means reaction times are much better. This is ideal in applications where a large number of rapid load fluctuations occur, such as in installations with welding equipment, or frequently occur with large inductive loads of short duration (<1 minute), such as hydraulic presses. Static VAr generators are an alternative to SCR-controlled capacitor banks.
In some cases, reactive power is only used by large constant loads, such as electric motors in pumping stations that run 24/7. In these cases, the control of the capacitor bank is not strictly necessary and the capacitors can be connected directly in parallel with the motor.
The impedance of a capacitor decreases with increasing frequency. This means that harmonic currents flow through the capacitor more easily than fundamental currents. This shortens the life of the capacitor. To reduce this effect, the capacitor bank is detuned. Add small coils to reduce high-frequency currents.
As the frequency increases, the coil has a higher impedance. If the capacitor bank is properly detuned, the chance of resonance is also reduced. Tuned capacitor banks are also possible. When adjusted correctly, they have a filtering effect. They are subsequently referred to as passive filters.
Capacitor banks can only reduce inductive reactive power. If the load is capacitive, the capacitor bank will not do any improvement. Static var generators (SVG) are able to compensate for capacitive reactive power.
