Filter

Filter is a component that filters waves, typically having two ports, one input and one output. The power filter transmits power to the device, greatly attenuating electromagnetic interference signals transmitted through the power supply and protecting the device from harm; At the same time, it can effectively control the electromagnetic interference signals generated by the equipment itself, prevent pollution of the electromagnetic environment, and harm other equipment.

Application areas:
Widely used in various sensors, controllers, and actuators.
(1) In the motor control system, filters can filter out the noise and clutter generated by the motor, improving the control accuracy and stability of the motor;
(2) In the battery management system, filters can filter out the noise and clutter generated by the battery, protecting its safety and extending its lifespan;
(3) In vehicle communication systems, filters can remove noise and clutter from communication signals, ensuring the stability and reliability of communication.

Application areas:
Widely used in various sensors, controllers, and actuators.
(1) In the motor control system, filters can filter out the noise and clutter generated by the motor, improving the control accuracy and stability of the motor;
(2) In the battery management system, filters can filter out the noise and clutter generated by the battery, protecting its safety and extending its lifespan;
(3) In vehicle communication systems, filters can remove noise and clutter from communication signals, ensuring the stability and reliability of communication.

Passive filter
Also known as LC filter. It is a filtering circuit designed using a combination of inductance, capacitance, and resistance, which can filter out one or more harmonics;
According to the working voltage, it can be divided into the following categories:
(1) Low voltage filters. Common power or signal filters used in low voltage applications include
Low pass filter: allows power/signals with frequencies lower than a certain frequency to pass through, and attenuates power/signals with frequencies higher than this frequency.
High pass filter: allows signals with frequencies higher than a certain frequency to pass through and attenuates signals with frequencies lower than this frequency.
(2) High voltage filters. Low pass filters are commonly used as power filters for applications with voltages greater than 100V.
Application: Widely used in various sensors, controllers, and actuators.
(1) In the motor control system, filters can filter out the noise and clutter generated by the motor, improving the control accuracy and stability of the motor;
(2) In the battery management system, filters can filter out the noise and clutter generated by the battery, protecting its safety and extending its lifespan;
(3) In vehicle communication systems, filters can remove noise and clutter from communication signals, ensuring the stability and reliability of communication.

Active Power Filter (APF):
It is a new type of power electronic device used for dynamically suppressing harmonics and compensating reactive power. It can compensate for harmonics and reactive power that vary in size and frequency. The device requires power supply (to compensate for harmonics in the main circuit), and its application can overcome the shortcomings of traditional harmonic suppression and reactive power compensation methods such as LC filters (which can only provide fixed compensation), achieve dynamic tracking compensation, and can compensate for both harmonics and reactive power


Future Development Trends:
The commonly used filters on the market are passive filters, which attenuate signals below or above a specific frequency. However, passive filtering devices also have their own shortcomings and deficiencies that cannot be overcome. With the widespread application of various power devices, a large amount of harmonic and reactive currents are injected into the power grid, causing grid pollution and leading to increasingly serious power quality problems. To improve the above problems, relevant work is currently being actively carried out, contributing to the development and application of active filters in the market.