Transcript for:
IGBT Working Logic, Features, and Applications

Hello friends! In this video, I will explain the  basic working logic of IGBTs, their features and   where they are used. The name IGBT comes from  the abbreviation of the initials of the English   words Insulated Gate Bipolar Transistor. It  is a power electronics circuit element formed   by the development of the best features of the  MOSFET and BJT transistor. It appears in many   areas used for switching purposes. IGBTs, which  can act as TRIACs or transistors when needed,   are used extensively, especially in  UPSs that require high switching speed.  The IGBT is the combination of BJT and MOSFET.  Its name also implies the fusion between them.   “Insulated Gate” refers to the input part of  MOSFET having very high input impedance. It does   not draw any input current rather it operates  on the voltage at its gate terminal. “Bipolar”   refers to the output part of the BJT having  bipolar nature where the current flow is due   to both types of charge carriers. It allows it  to handle very large currents and voltages using   small voltage signals. This hybrid combination  makes the IGBT a voltage-controlled device.  IGBTs have three pins. One of them is the Gate,  the other is the Collector and the last one is   the Emitter. The abbreviations G, C and E are  used for these. Their locations may not always   be like this. Pin locations may change according  to the type. Their symbols are as you see on the   right. These two symbols are also used. You may  also encounter symbol drawings similar to these   that differ slightly. As can be understood from  the pin names, we can understand that it shows   both MOSFET and BJT transistor features. If you  remember, the Gate pin is located in the MOSFET,   while the Collector and Emitter pins  are located in the BJT transistor.  The working logic is similar to the working  principle of the same MOSFET. With the trigger   voltage applied to the Gate pin, a large current  between the Collector Emitter is controlled.   In other words, as in the same MOSFET,  current control is provided with voltage.  Now let's look at the advantages and disadvantages  of IGBTs over BJT and MOSFET transistors. As   a whole, IGBT has the advantages of both BJT  and MOSFET. If we start with the advantages;   It has higher voltage and current carrying  capabilities. It has a very high input impedance.   It can switch very high currents using very low  voltage. It is voltage controlled, meaning there   is no input current and input losses are low. It  has a higher power gain than both BJT and MOSFET.   It has a higher switching speed than a BJT. Disadvantages; It has a lower switching speed   than MOSFET. It has a locking problem due to  its PNPN structure resembling a thyristor.   It is more costly than BJT and MOSFET.  These were the prominent advantages and   disadvantages. So where are IGBTs used?  Now let's look at where they are used.  IGBTs have numerous applications used in  AC and DC circuits. Here are some of the   important applications of IGBT; SMPS (Switched  Mode Power Supply) is used to power sensitive   medical equipment and computers. These devices  regularly supply power to electronic devices.  It is used in the UPS (Uninterruptible Power  Supply) system that provides energy during   power outages. UPSs store energy in batteries  when there is electricity. When there is a power   outage, the DC electricity in the batteries is  converted to AC and used in electrical devices.  Similarly, it is used in inverter circuits  that meet the need for power conversion,   which we can encounter in many places. It is also used in devices known as   solar inverters. Solar inverters provide  the conversion of the energy in solar   panels to be stored in batteries  and then used in devices at home.  These are the basic structure of IGBTs  and where they are used. I hope you liked   this video and it is useful. Hope to  see you in the next lesson. Goodbye.