Proposed System must contain:
1: Sense the voltage and frequency of the generator output.
2: If load increase the voltage and frequency of the
generator decrease.
3: If load decrease the voltage and frequency of the
generator increase.
4: If demand decrease the power will be diverted to dump
load.
5: If demand increase the power will be diverted to main
load.
6: If demand
increase than that of actual power production then system will be off (i.e.
automatic power will cut down to the main load and send to dump load).
System
Description:
Ø Voltage sensor that senses the voltage
across the load, and gives output.
Ø A microcontroller which interprets the
readings corresponding to a sequence finds the error in the voltage and
generates a pulse width modulated wave as per the error in voltage at any
instant.
Ø
A thyristor based
uncontrolled rectifier circuit which is connected to a series resistive dump
load and is switched by the PWM wave generated by the microcontroller.
Algorithm of system:
Step1: Set a reference voltage and frequency which is fixed
(for programming based it is 5 V)
Step2: Sense the voltage and frequency
Step3: Both signals will compared and error output is fed to
microcontroller as input
Step4: The error is compared with a very
high frequency triangular wave and the corresponding output is fed to the PI
Controller section of the code in microcontroller
Step5: The PI controller is turned on
only after an initial voltage of around 230V has been achieved after the start
so that the initial errors when the voltage is rising do not interfere with the
integral part of the controller
Step6: The output of the PI
controller section is the required PWM signal for switching the IGBT to
regulate the dump load
Step7: The PWM output is then given
to the thyristor through an opto-isolation and pulse driver circuit
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