What are the types and selection of inverter filters? How to choose and use filters?

1. Types of inverter filters

Frequency converters are common in modern industrial production electrical equipment. Whether it is a small or large frequency converter, its power supply and output will generate noise and interfere with other electrical equipment and systems, and even affect human health. Therefore, in order to reduce this interference, the design of the frequency converter filter is very important.

1.EMI filter

EMI filter is widely used in inverters and other electronic devices. It can effectively filter electromagnetic interference, thus ensuring the stability and reliability of the equipment. EMI filter can be divided into load side filter and power side filter.

The load-side filter is usually installed at the output of the inverter to filter the high-frequency noise signal brought by the inverter to avoid interference with other equipment and systems. The power-side filter is usually installed at the input of the inverter to filter the high-frequency noise signal brought by the power supply to ensure that the power provided by the power supply is clean and stable.

2.LC filter

LC filters are usually used at the output end of the inverter. Their function is to reduce the potential harmonics of the inverter and the noise interference that may be generated by the inverter electrical equipment. LC filters are realized through the joint design of inductors and capacitors. The inductors and capacitors work together to achieve the effect of reducing the jitter of the current waveform within a certain frequency range.

3.RC filter

RC filter is also a commonly used inverter filter. It is easy to use, relatively low cost, and can be installed at both the output and input ends. RC filter is composed of resistors and capacitors. Its working principle is to suppress high-frequency interference electrical signals based on the characteristics of RC circuit, thereby suppressing noise and electromagnetic interference and improving the stability of equipment operation.

2. Selection method of inverter filter

1. Choose according to the electromagnetic interference noise situation

The electromagnetic interference noise generated by the inverter is usually caused by voltage, current interference and high-frequency noise. At this time, it is necessary to select according to the specific situation of these aspects. If the voltage and current interference are more serious, you need to choose an EMI filter, and if the high-frequency noise is more obvious, you can choose an LC filter or an RC filter.

2. Choose according to the quality requirements of the output signal

The higher the quality requirement of the inverter's output signal, the more advanced the filter required. Therefore, if there are strict output electrical signal specifications, it is necessary to select EMI filters and LC filters with higher filtering effects.

3. Choose based on the requirements of specific applications

Different application needs have different requirements on the performance of filters. For example, when used in aircraft, high-speed trains and other environments, it is necessary to suppress EMI noise interference and harmonics, requiring the use of LC filters with better filtering effects; while in low-frequency situations, the use of RC filters can meet the needs.

3. How to use the inverter filter

1. How to use EMI filter

When installing an EMI filter, special attention should be paid to the connection between its pins, channels and plugs to avoid installation errors and wrong pin connections. Before normal use, the filter needs to be tested to ensure that the filter is in normal working condition and can effectively filter electromagnetic interference signals.

2. How to use LC filter

When using LC filters, they are generally installed at the output end of the inverter. When adjusting the LC circuit parameter values, special attention should be paid to the matching of phase and frequency. In order to ensure the reliability and stability of the LC filter, when selecting inductors and capacitors, attention should be paid to their rated voltage and power to ensure that they are not damaged during operation.

3. How to use RC filter

When using RC filters, regular inspection and maintenance are required, especially inspection of capacitors to ensure that they are working properly and have no external damage. When adjusting the parameters of the RC circuit, attention should also be paid to the matching of phase and frequency to ensure that the filtering effect is ideal.

In short, when selecting a frequency converter filter, it is necessary to select a suitable filter based on the actual on-site environment and equipment requirements. During use, the installation, adjustment and maintenance of the filter also require great attention to ensure efficient, stable and reliable operation of the frequency converter.