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Please Select a Region. Sign up using Facebook. I see no difference when using an IGBT. Please Select a Language. Why I am getting this substrate picture, when i create a new workspace? Care needs to be taken in implementing desaturation detection to prevent false tripping.

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IGBT Overcurrent and Short-Circuit Protection in Industrial Motor Drives

The diodes shown in the schematic ensure that the IGBT collector-emitter voltage is only monitored by the detection circuit during the on-time, when in normal operation the collector-emitter voltage is very low 1 V to 4 V typically. All of these gate driver functions have a positive impact on overall system reliability and efficiency. This results in a rapid increase in the collector-emitter voltage. Enough collector current and the device comes out of saturation.

There is also a strong dependency on the IGBT collector-emitter voltage, so the parallel trend toward higher dc bus voltage levels in industrial drives results in further reduction in short-circuit withstand times. The ability to accept a bipolar power supply on the isolated side of the gate driver provides additional headroom for the induced voltage transient. Please Select a Region. A blanking time is generally inserted between the beginning of the turn-on signal and the point at which desaturation detection is activated in order to avoid false detection.


There is an initial controlled overshoot of about 80 V above the V DC bus voltage due to the higher impedance in the turn-off during desaturation protection.

For the dc bus current sensing circuit, a small filter must be added in order to avoid false tripping, since the dc bus current is discontinuous with potentially high noise content. The curves on every IGBT data sheet I’ve seen show a typical junction drop relationship between voltage and current collector-emitter when the device is gated on. A current source charged capacitor or an RC filter is also usually added to introduce a short time constant into the detection mechanism in order to filter spurious trips introduced by noise pickup.

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The total delay to commencement of IGBT turn-off is seen to be around ns. By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

IGBT and MOSFET Desaturation Protection

I’ve heard IGBTs described as desaturating if too much current passes through them, particularly in the context of drivers with desat protection. I see no difference when using an IGBT. Heat sinks, Part 2: These amount to an additional 0.


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Radiation Detection Circuit 1. For instance, a negative supply rail of —7. He even had experimental data and waveforms, but unfortunately I don’t have permission to post them. Our header files are static or dynamic library 1.

These techniques are illustrated in Figure 2. By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

Dec 248: This accentuates the importance of the gate driver circuit and its overcurrent detection and protection features. Andy aka k 10 And as you well know, in the active region the power dissipation increases dramatically.

Hi Friends, They say that when this Desaturation occurs, there is an increase in the collector potential: How to upload a counter value to a website automatically 3. The time now is