The role of diodes in frequency converters
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The role of diodes in frequency converters

Posted Date: 2024-02-07

What are the specific roles of diodes in frequency converters?

The following functions of diodes in frequency converters:

Stable supply of voltage to each branch power supply. In the switching power supply and drive circuit of the inverter, each inverter uses zener diodes with different voltage stabilization levels as the voltage stabilizing components in these circuits.

Play the role of over-voltage protection. In some circuits of the inverter, some brands of inverters use some instantaneous suppression diodes as overvoltage protection components for a certain branch. When the power supply supplying a branch circuit has overvoltage due to some reason, the action of the diode is instantly suppressed and the overvoltage protection function is implemented in a timely manner.

Another function of the diode in the frequency converter is to convert pulsating alternating current into pulsating direct current for use in switching power supplies and various branches. The switching power supply part of the frequency converter has the most practical rectifier diodes, and the three-phase rectifier bridge is the most common. Secondly, the AC power output from the secondary output of the switching transformer is also rectified by some rectifier diodes.

When it comes to the role of diodes in frequency converters, it is also mentioned that diodes, in conjunction with other components, also play a role in signal conversion. The diode used for signal conversion in the frequency converter is mainly the circuit part of the drive circuit that triggers photoelectric coupling to send out six pulse signals. In this part, the diode is combined with some resistors and capacitors to convert the square wave into sharp pulses with positive and negative polarity to supply the drive The photocoupler in the circuit reduces the risk of module explosion caused by false triggering.

When it comes to the role of diodes in frequency converters, the use of diodes as indicator lights is also mentioned. In the frequency converter, the operating status, running direction, operating status, charging and discharging, etc. of the frequency converter all use light-emitting diodes as indicator lights.

How to detect the quality of diode components in frequency converters

When we disassemble the casing of the frequency converter, we will see that some different types of diode components are used inside the frequency converter. At this time, the frequency converter maintenance personnel need to know the quality of the diode components if they want to repair the faulty frequency converter. Judgment method: If you want to judge the quality of diode components, it is difficult to see the quality of the diode with the naked eye. So how do we detect the quality of the diode components in the frequency converter?

When testing the quality of the diode components in the frequency converter, it is recommended that you use an analog multimeter or a digital multimeter to judge. Use a pointer multimeter to detect the quality of the diode components in the inverter.

When using a pointer multimeter to detect the diode components in the frequency converter, the first step is to select the appropriate measurement gear. Usually the measurement gear is to set the gear switch to R × 100 or R × 1K. The second step is to connect the two test leads of the multimeter to the two pins of the diode component under test. Diodes have positive and negative polarities. When measuring, you must know how to identify the polarity of the diode, which is usually found on the surface of the diode. There will be a mark as a polarity mark for the diode.

When measuring a diode with an analog multimeter, connect the black test lead of the multimeter to the negative terminal of the diode and the red test lead to the positive terminal of the positive terminal of the diode. At this time, the pointer of the multimeter should be infinity and the pointer should not swing. Then exchange the two test leads, that is, connect the black test lead of the multimeter to the anode of the diode, and the red test lead to the cathode of the anode of the diode. At this time, the needle of the multimeter should swing and stay at a resistance of about a few hundred ohms.

Review Editor: Huang Fei


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