Short-circuits in Industrial Environments Industrial motor drives can operate in a relatively harsh environment in which high temperature, ac line transients, mechanical overload, miswiring, and other contingencies can occur. The total delay to commencement of IGBT turn-off is seen to be around ns. Hi Friends, They say that when this Desaturation occurs, there is an increase in the collector potential: 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. IGBT overcurrent and short-circuit protection are implemented using a range of methods in the experimental hardware.
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The diodes shown in the schematic ensure that edsaturation 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. Part and Inventory Search. Here is a schematic which I am referring to: Ultrasonic transducer driver 1. In Figure 6, the delay between the hardware trip signal, the PWM output signal, and the actual gate-emitter waveform of the upper IGBT in one of the inverter legs is shown.
Be it a BJT or a MOSFET, if there is too much current it will no longer be fully saturating and for a heavy duty switching circuit this is usually the time to say farewell to the device.
A blanking time is generally inserted between the beginning of the turn-on signal resaturation the point at which desaturation detection is activated in order to avoid false detection.
Additional flexibility in the control of switching rates can be provided by utilizing asymmetric gate resistors for turn-on and turn-off. How to upload a counter value to a website automatically 3.
IGBT Overcurrent and Short-Circuit Protection in Industrial Motor Drives | Analog Devices
Miller clamping on turn-on. A market-wide trend in industrial motor drives desaaturation an increasing demand for higher efficiency coupled with increased reliability and robustness. His area of expertise is power conversion and control in ac motor control applications.
Post as a guest Name. Care needs to be taken in implementing desaturation detection to prevent false tripping.
IGBT Overcurrent and Short-Circuit Protection in Industrial Motor Drives
Do anyone know well in IGBT? Gate driver desaturation detection can act significantly faster than the overcurrent detection methods described previously, and is important for limiting the extent to which short-circuit currents are allowed to rise, thus enhancing overall system reliability beyond the levels achievable even with fast overcurrent protection.
As the fault occurs the current starts to increase rapidly—in reality the current is much higher than shown as the measurement is taken with a bandwidth limited 20 A current probe for illustration only. These amount to an additional 0.
Renesas Electronics Corporation This accentuates the importance of the gate driver circuit and its overcurrent detection and protection features.
Industrial motor drive reliability is strongly linked to the IGBT protection circuits. Taking resistor technology beyond RoHS.
The desaturation voltage reaches the 9 V trip level and the gate driver begins to shut down. However if a short-circuit event occurs, the IGBT collector current increases to a level that drives the IGBT out of the saturated region and into the linear region of operation.
IGBT overcurrent and short-circuit protection are implemented using gibt range of methods in the experimental hardware. In addition, the improvements in ugbt allow for the use of smaller die, 2 reducing module size but lowering thermal capacity, which further reduces the withstand time. I’ve heard IGBTs described as desaturating if too much current passes through them, particularly in the context of drivers with desat protection.
Email Required, but never shown. The experimental setup utilizes a 3-phase inverter powered from the ac mains through a half wave rectifier. Please Select a Region.