How does the harmonic filter reactor absorb the harmonic current from the power grid?

There are numerous harmonic sources such as rectifiers, converters, and frequency converters in the power grid. The high-order harmonics generated by these devices can seriously endanger the safe operation of main transformers and other electrical equipment in the system. Harmonic filtering reactors are widely used in high and low voltage filtering cabinets to absorb and filter out harmonic currents.

The harmonic filter reactor absorbs the grid harmonic current in the following way:

I. Basic Principle

Impedance characteristic: The reactor presents a high impedance to high-frequency harmonic currents, hindering their passage and thereby reducing the amount of harmonics entering the power grid.

II. Working Method

1. Series reactor: Connected in series with the capacitor to form an LC filter circuit, tuned to a specific harmonic frequency, and absorbing the harmonic current at that frequency.

2. Parallel reactor: Connected in parallel with the load, it provides a low-impedance path, allowing harmonic currents to flow into the reactor instead of the power grid.

III. Main Functions

1. Harmonic suppression: By utilizing the high-impedance characteristic, the harmonic current is prevented from entering the power grid.

2. Resonance Suppression: Prevent the capacitor from forming resonance with the grid inductance, and avoid the amplification of harmonics.

3. Reactive power compensation: While suppressing harmonics, it also provides reactive power compensation to improve the power factor.

IV. Application Scenarios

1. Industrial equipment: Used for devices such as frequency converters and electric arc furnaces that generate a large amount of harmonics.

2. Commercial buildings: Suitable for use in office buildings, shopping malls and other places with high levels of harmonic interference.

3. Power System: Used in substations, distribution systems, and other places where harmonic control is required.