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• Project change

  Michael Skrepsky • 01/01/2017 at 14:14 • 0 comments

  I have sold the generator (with both old and new regulator), because it occupied too much space and i got bored with it. But i don't scrap the project, because i have old stationary diesel engine and i got 1kW single phase alternator without regulator, so i will change everything to suit that.

• Mechanical/electrical construction finished

  Michael Skrepsky • 08/08/2015 at 21:28 • 0 comments

  It works!!! But it oscillates with about 1s period from 250V to 400V (phase to phase) or regulates only partially, reaching 500V. I need to make frequency compensation and protection, and replace temporary incremental algorythm with PID or something better. I will take a notebook to it and make it throw values through serial/USB. If it does not work, i would make basic ON/OFF regulation.

  Relay is now switched off by software. Will update schematic after finished.

  The temporary test code (that has fixed oscillation, but regulates poorly):

  // experimental AC alternator voltage controller
  
  // Uses AC Control V1.1
  
  #include <avr/io.h>
  #include <avr/interrupt.h>
  
  #define DETECT 2  //zero cross detect
  #define GATE 9    //triac gate
  #define PULSE 5   //trigger pulse width (counts)
  #define VOLTPIN A0//voltage measurement
  #define LEDPIN 13
  int i=450;
  int voltage = 0;  // variable to store the value coming from the sensor
  unsigned long oldtime;
  unsigned long time;
  
  void setup(){
  
    // set up pins
    pinMode(DETECT, INPUT);     //zero cross detect
    digitalWrite(DETECT, HIGH); //enable pull-up resistor
    pinMode(GATE, OUTPUT);      //triac gate control
  
    // set up Timer1 
    //(see ATMEGA 328 data sheet pg 134 for more details)
    OCR1A = 100;      //initialize the comparator
    TIMSK1 = 0x03;    //enable comparator A and overflow interrupts
    TCCR1A = 0x00;    //timer control registers set for
    TCCR1B = 0x00;    //normal operation, timer disabled
  
  
    // set up zero crossing interrupt
    attachInterrupt(0,zeroCrossingInterrupt, RISING);    
      //IRQ0 is pin 2. Call zeroCrossingInterrupt 
      //on rising signal
      
  
    // initialize serial communication at many bits per second:
    Serial.begin(115200);
  
  }  
  
  //Interrupt Service Routines
  
  void zeroCrossingInterrupt(){ //zero cross detect   
    TCCR1B=0x04; //start timer with divide by 256 input
    TCNT1 = 0;   //reset timer - count from zero
    
  
    // read the input on analog pin 0:
    voltage = analogRead(VOLTPIN); // synchronous voltage measurement to prevent ripple
    if (voltage > 640) i=i+5; // emergency voltage decrease (does not work)
    time = millis() - oldtime;
    oldtime = millis(); // period (frequency) measurement for future compensation of generator revs/min change
  }
  
  ISR(TIMER1_COMPA_vect){ //comparator match
    digitalWrite(GATE,HIGH);  //set triac gate to high
    TCNT1 = 65536-PULSE;      //trigger pulse width
  }
  
  ISR(TIMER1_OVF_vect){ //timer1 overflow
    digitalWrite(GATE,LOW); //turn off triac gate
    TCCR1B = 0x00;          //disable timer stopd unintended triggers
  }
  
  void loop(){ // code
  if (voltage > 620) i=i+1; // decrease phase
  if (voltage < 580) i=i-1; // increase phase
  if (i > 600) i = 600; //limit
  if (i < 300) i = 300; //limit
  //i--;
  OCR1A = i;     //set the compare register phase desired.
  //if (i<300){i=550;}                      
  delay(20);
  
  
    // print out the value you read:
    Serial.print(time); // write period of AC
    Serial.print("   ");
    Serial.print(i); // write phase
    Serial.print("   ");
    //Serial.println((10*voltage)/205); // 10*voltage in volts
    Serial.println(voltage); // voltage in ADC units - / 1024 * 5
  
  }

  
  

• baseplate

  Michael Skrepsky • 08/06/2015 at 21:03 • 0 comments

  baseplate completed, voltage transformers and connector installed.

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