Active Harmonic Filter (AHF) and Passive Harmonic Filter (PHF) are two different types of devices used for filtering in power systems. They have significant differences in structure, working principle and performance. Here are the main differences between them:
1. Structure and Composition:
Active Harmonic Filter: AHF uses active control technology, usually composed of power electronic devices and control circuits, which can actively generate opposite harmonics or clutter signals and inject them into the power grid to achieve a filtering effect.
Passive Harmonic Filter: PHFr is a passsive filter, which is mainly composed of passive components such as inductors, capacitors and resistors, and relies on inherent frequency characteristics to achieve filtering functions.
2. Filtering Principle:
Active Harmonic Filter: AHF interferes with harmonics or clutter signals in the power grid through active control technology, and has good filtering effect and dynamic response capability.
Passive Harmonic Filter: PHF uses the frequency characteristics of passive components such as inductors, capacitors and resistors to filter out signals at specific frequencies, and the filtering effect is relatively weak.
3. Performance Comparison:
Active Harmonic Filter: AHF has good filtering effect and dynamic response capability, and can quickly and effectively suppress harmonics and clutter in the power grid.
Passive Harmonic Filter: PHF is simple in design and low in cost, but its filtering effect and dynamic response capability are relatively weak, so it is suitable for some occasions that do not require high filtering performance.
To sum up, there are obvious differences between active harmonic filter and passive harmonic filter in terms of filtering principle, structure and performance. When selecting a filter, the respective advantages and disadvantages should be weighed based on system requirements and economic considerations, and the most suitable filter type should be selected to ensure the normal operation and stability of the power system.