PV inverter IGBT overcurrent

Why is IGBT used in a central inverter?

The IGBT is usually used to the central inverter topology as it can carry high current capacity with several fluctuations (overshoot and undershoot) due to the radiation disturbances because of the clouds cross or sandy windstorm. However, the investigated work can be implemented to other inverter applications which used MOSFET.

What is over current protection mechanism in PV inverter?

As previously discussed, the simultaneous injection of peak active power from PVs and reactive power into the grid for voltage support can trigger the over current protection mechanism in PV inverter. The triggering of over current protection will lead to disconnection of inverter from the grid which is unfavourable during LVRT period.

How do IGBTs work in a PV inverter?

During operation inside a PV inverter, IGBTs are subject to AC stress conditions as opposed to DC stress conditions. This typically consists of a 60 Hz on-off cycle, with a Pulse-Width-Modulated (PWM) signal on the order of 10 – 15 kHz superimposed on the lower-frequency cycle.

Can IGBT degradation cause a failure of an inverter?

This IGBT degradation would most likely not cause the failure of an inverter, but could degrade performance. Furthermore, it is highly questionable if a device exhibiting significant instability would operate for the expected lifetime of an inverter (i.e. 5 to 20 years).

How to avoid over current in PV inverters during fault-ride-through period?

Hence, to avoid over current in PV inverters during fault-ride-through period, active power curtailment is necessary. The authors have formulated an expression to evaluate pseudo inverter capacity (PIC) for over current limitation as in (25). $$PIC= \frac {1-VUF} { {u}_ {base}}\times {u}^ {+}\times S$$

Are insulated-gate bipolar transistors a good choice for solar inverter applications?

For solar inverter applications, it is well known that insulated-gate bipolar transistors (IGBTs) ofer benefits compared to other types of power devices, like high-current-carrying capability, gate control using voltage instead of current and the ability to match the co-pack diode with the IGBT.