吾妻思萌

Vibration Test Instrument Published on 2024-1-22 14:44 In the transistor era, the power of MOS tubes was very large, and the power of power amplifiers reached dozens of kW. Now the capacity is even higher, and the capacity is hundreds of kW. The capacity of MOS...

Yes, sir. Now high-voltage fast charging and high-voltage 800V electric vehicle motors are all IGBT modules.

I think IGBT is mostly power and MOS is mostly control.

This UHV seems to be GTO.

吾妻思萌

maychang posted on 2023-6-4 07:48 Books on switching power supply design will definitely mention how much the AC mains voltage is and how much the switch tube withstand voltage needs to be. As for the odd harmonic content...

Teacher May,

I would like to ask you, in my country, many UHV 110kv DC transmission systems use IGBT, MOS or

What about GTO?

maychang

Azuma Simeng posted on 2024-1-22 15:00 Teacher May, I would like to ask you, in my country, many UHV 110kv DC transmission systems use IGBT, MOS or GTO?

In the electric power industry, 110kV is not considered ultra-high voltage. Only 330kV~800kV are considered extra-high voltage, and 1000kV is considered ultra-high voltage.

maychang

Azuma Simeng posted on 2024-1-22 15:00 Teacher May, I would like to ask you, in my country, many UHV 110kv DC transmission systems use IGBT, MOS or GTO?

In high-voltage direct current transmission, the converter valve used at the receiving end is not IGBT, MOS, or GTO, but an ordinary thyristor.

吾妻思萌

maychang posted on 2024-1-22 16:25 In high-voltage direct current transmission, the converter valve used at the receiving end is not IGBT, MOS, or GTO, but ordinary thyristor.

I learned it, teacher. The ultra-high voltage kkV-level thyristors are not as big as a car.

maychang

Azuma Simeng posted on 2024-1-25 20:46 I learned it, teacher, the UHV kkV-level thyristors are not as big as a car.

Thyristors do not have a withstand voltage of MV level. To reach a voltage of hundreds of kV, multiple stages need to be connected in series.

The reason why thyristors are used for inverters is that they can achieve the maximum current capacity, which is much larger than MOS, IGBT, etc. The operating frequency of thyristors is not high, much lower than MOS and IGBT, but the AC frequency of the inverter output is the industrial frequency, and thyristors can do the job.

maychang

Azuma Simeng posted on 2024-1-25 20:46 I learned it, teacher, the UHV kkV-level thyristors are not as big as a car.

It is indeed larger with the radiator, but not as big as a car.

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MOS tubes can be widely used to replace triodes. Another important reason is that they can be used in parallel. Parallel use is convenient, and the conversion efficiency is high when working. High power can be used with air cooling.

PCB板厂-TONY

maychang posted on 2023-6-2 09:53 After talking for a long time, I still haven’t explained why MOS tubes have become the protagonist of power electronics.

interesting

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It is mainly used in power amplifiers and DC voltage regulation. In DC power supplies, MOSFET tubes have replaced triodes and become the main character. The power amplifier has changed from a Class B amplifier to the current Class D amplifier, and the series voltage regulation has become a switching voltage regulation.

The electric welding machine is also controlled by MOS tube.

It is more convenient to use triodes for small signals. NPN tubes are more commonly used than PNP tubes.

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The reason why MOSFET tubes replace high-power triodes is

First, the single voltage and current of a MOS tube exceed those of a triode, and the power of a single tube is much greater than that of a triode.

Second, multiple MOS tubes can automatically balance the current when working in parallel, so the output power can be combined into tens or hundreds of kW by connecting the chassis in parallel. However, the parallel performance of triodes is much worse.

Third, the conversion efficiency of Class D amplifiers is higher than that of Class B amplifiers. The transistor amplifier cannot be made larger. When the transistor amplifier on the vibration table reaches 10KW, it needs to be cooled with water. When multiple transistor amplifiers are connected in parallel, internal imbalance is likely to occur and they may be damaged.