Designing an AVR for Diesel Generator

I am in the process of designing an Automatic Voltage Regulator (AVR) for a diesel generator's alternator, utilizing a microcontroller-based approach.

Currently, I do not have access to the specific generator to provide detailed specifications, but my general design framework is as follows:

• Rotor Excitation Control:

  • An IGBT is employed to regulate the rotor excitation current.

  • The IGBT is driven by a TLP350 optocoupler, which interfaces with the microcontroller for control purposes.

  • The PWM pin of the TLP350 is directly connected to the microcontroller.

The schematic diagram of my proposed circuit is this :

Inquiries:

1. Circuit Validation:
   Does the attached circuit effectively control the rotor excitation current? Are there any improvements or considerations I should be aware of?

2. Initial Rotor Excitation Strategy:
   Upon startup, is it necessary to supply a higher-than-nominal excitation current to the rotor for a brief period before transitioning to the nominal current? If so, what magnitude and duration are recommended for this initial over-excitation?

3. Implementation of Initial Excitation:
   What circuit configurations or methodologies are advisable to achieve the initial rotor excitation current boost during startup?

4. PWM Signal Considerations:
   Since the PWM pin of the TLP350 is directly connected to the microcontroller, is this setup sufficient for generating the required duty cycle and PWM signal, or are there additional considerations I should take into account?

appreciate your help