VFD's and 3phase Induction motors FAQ corner / pls. Read all first

Hi @speedy
calculations are ok but let say when i just was testing on breadboard the resaul was deferent as I tested one channel compared 6 parallel channels
and then what it actually makes the situation better resault was when I used side resistors arround 2.5 time bigger than for input resistors ,well as your
calculations, what if using 390 ohm for input resistors and something arround 1 K for side one.
unfortunately ive done this a few months ago and no video here.i attach AutoCAD file for sprint layout. please you do final edit
here is my own set up

about the jumper ,YES buddy

Merry Christmas everyone ...

hi dear ALL
@speedy @noorbeast if you can advice me

i am doing a research and i found out that you can control VFD via rs-485 communication port
( MAX485 module / RS-485 module / TTL to RS-485 converter For Arduino )
connected to ( SG+,SG- ) = in the VFD. <-- after reading manual-

I Think it is ( very helpful and it can help a lot of sim builders to do there project easily )

what i am asking for is :

how to program it so it could work with sim tools with a feed back for the position of the Motor


example :



Arduino sketch A:


/*
Author : Kunchala Anil [anilkunchalaece@gmail.com]

Interfacing VFD with Arduino Via RS485 using MODBUS Protocol
MODBUS protocol
-------------------------------------------------------------------------
| Start Bit | Address | Function_Command | DATA | LRC or CRC | Stop bit |
| : | 2bytes | 2 bytes | | 2 bytes | \r\n |
-------------------------------------------------------------------------

Function Code : The format of data characters depend on function codes
The available function codes are described as follows:
0x03 : Read data from register
0x06 : Write single data to register
0x10 : Write multiple data to registers

MODBUS Protocol can be implemented in two ways ASCII or RTU(Remote Terminal Unit)
iam gonna use ASCII mode for this example

____________________________________________________________________________
| Content Address Functions
|-------------------------------------------------------------------------
| B1 B0
| 0 0 --> NO function
| Bit 0 - 1 0 1 --> Stop
| 1 0 --> Run
| 0x2000 1 1 --> Jog + Run
|
| Bit 2 - 3 Reserved
|
| B5 B4
| 0 0 --> No function
| Command Bit 4 - 5 0 1 --> FWD
| Read / Write 1 0 --> REV
| 1 1 --> Change Direction
|
| Bit 6 - 15 Reserved
|
| 0x2001 Frequency Command
|
|__________________________________________________________________________________


Command Address B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 Hex Equalent
RUN 0x2000 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0x0012
STOP 0x2000 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0x0011
Format if data send to the VFD
':' --> Start bit in Ascii mode
\r\n --> Stop bit


*/

//commands values
#define VFD_START 1
#define VFD_STOP 2
#define VFD_SPEED 3

#define MAX_SIZE 20 // max size of data buffer

char speed_vfd[] = ":01062001";
const char start_vfd[] = ":010620000012C7\r\n";
const char stop_vfd[] = ":010620000011C8\r\n";
char data_buffer[MAX_SIZE];

void setup(){
Serial.begin(9600);
}//end of setup


void loop(){

serial_ask(); /* ask question the user to enter
1 to start the VFD
2 to stop the VFD
3 to set the speed of VFD */
int val = serial_check(); /* wait for user to enter the data and convert
it to Int and return value into function */
perform_action(val); /* perform the action based on the user entered value
which is passed to the function */

}//end of loop


/*
SERIAL_ASK() FUNCTION : this function is used to ask the user to enter the user choice via Serial monitor
*/
void serial_ask(){
Serial.println("Please Enter all values followed by \n");
Serial.println("Please enter the valid code to perform");
Serial.println("-------------------");
Serial.println("CODE\t ACTION");
Serial.print(VFD_START);Serial.println("\t START VFD");
Serial.print(VFD_STOP);Serial.println("\t STOP VFD");
Serial.print(VFD_SPEED);Serial.println("\t SET SPEED");
Serial.println("-------------------");
}//end of serial_ask() fucntion


/*
SERIAL_CHECK() FUNCTION : this function is used to receive the data into data_buffer
*/
int serial_check(){
while(!data_received())
{
//wait until full data is received
}//end of while
return atoi(data_buffer);
}//end of serial_check() function


boolean data_received(){
static byte index = 0;
while(!Serial.available())
{
//wait until user enter the data
}

if(Serial.available())
{
char input = Serial.read();
if(input !='\r')
{
data_buffer[index] = input;
index = index + 1;
}else
{
data_buffer[index] = 0;//null terminate the character array to make it string
index = 0;
return true;// we received the full code return true
}//end of ifelse condition
}
return false;
}//end of data_received()) function

void perform_action(int val){
switch(val)
{
case VFD_START:
Serial.println("VFD START");
VFD_control(start_vfd);
break;

case VFD_STOP:
Serial.println("VFD STOP");
VFD_control(stop_vfd);
break;

case VFD_SPEED:
Serial.println("SET SPEED");
set_speed();
break;

default:
error_message();

}//end of switch
}//end of perform action

void VFD_control(const char* command){
Serial.print(command);
Serial.println();
}

void set_speed(){
char freq_hex[4];//temporary string for sprintf
Serial.println("Set Speed");
Serial.println("enter the frequency");
int freq = serial_check();
Serial.print("the frequency you entered is");
Serial.println(freq);
sprintf(freq_hex,"%04X",freq);//convert it to hex using sprintf
strcat(speed_vfd,freq_hex);
cal_LRC();

}//end of set_speed() fucntion

void cal_LRC(){
int val = calculate(); //function to calculate the decimal value
convert_to_hex(val);// function to convert the decimal value to HEX
}//end of cal_LRC() fucntion


//CALCULATE() FUNCTION
int calculate(){
int val[strlen(speed_vfd)/2]; // val[] array is used to store the decimal value for two HEX digits
for (int i = 1, j = 0 ; i < strlen(speed_vfd); i = i+2, j++ ) //i = i+2 because we are finding the decimal equalent for two HEX values
{
val[j] = conv(speed_vfd,speed_vfd[i+1]); // function to convert Two Hex numbers into Decimal Value

}//end of for loop

int sum = find_sum(val); // function to calculate total sum of decimal equalents
return sum;
}//end of calculate() function

//FUNCTION_SUM() FUNCTION
int find_sum(const int * val) // we are passing an array to the function
{
int sum = 0;
for(int i=0;i<= (strlen(speed_vfd)/2) - 1;i++)
{
sum = sum + val;
}//end of for loop
return sum;
}//end of find_sum() function

//FUNCTION TO CONVERT HEX TO THE DECIMAL VALUE
int conv(char val1,char val2){
int val_a = toDec(val1); // convert to the decimal value
int val_b = toDec(val2);
return (val_a*16) + val_b; // converting decimal value into HEX decimal Equalent B1*16 + B0
}//end of conv() function

int toDec(char val){
if(val<='9')
{
return val - '0'; // please see the ASCII table for clarification
}
else
{
return val - '0'-7; // 7 is offset for capital letters please see the ASCII table
}

}//end of toDec() function

void convert_to_hex(int val){
char hex[5];
utoa((unsigned)val,hex,16); // utoa() function is used to convert unsigned int to HEX array (whatever the base we specified as third argument)

int hex_val = (int)strtol(hex,NULL,16);// strtol() is used to covert string into long int according to the given base

hex_val = ((~hex_val) + B01) & 0xff; /* finding the 2's complement of the number hex_val
'~' operator is the logical not and adding B01 to it and logical anding with 0xff
to omit any excess bites otherthan 8 bits or 1 byte
*/
Serial.print("the LRC value is : ");
Serial.println(hex_val,HEX);
char hex_val_str[4];
sprintf(hex_val_str,"%0.2X",hex_val);// putting hex value in the string back
Serial.print("the concated string is : ");
strcat(speed_vfd,hex_val_str);
char ter[] = "\r\n";
strcat(speed_vfd,ter);//adding terminators at the end STOP bits
Serial.println(speed_vfd);
}//end of convert_to_hex() fucntion


void error_message(){
Serial.println("You Entered Wrong Command");

}//end of error_message()



Arduino sketch B:


#include <SoftwareSerial.h>

// RS485 connections
// D8 = DI (TX)
// D9 = DE
// D10 = RE
// D11 = RO (RX)

// adjust speed
String speed=":010203030BB837\r\n";


char* read_speed=":01040300";
char* change_speed=":010203030BB8";
char* stop=":01030108";
char* start=":01030101";


SoftwareSerial myserial(11,8); // RX, TX

void setup() {
Serial.begin(9600);
pinMode(9,OUTPUT);
pinMode(10,OUTPUT);
myserial.begin(9600);
digitalWrite(9,LOW); digitalWrite(9,LOW);
}

void setSpeed(int v) {
Serial.print("Set new speed "); Serial.println(v,DEC);
char* n=change_speed;
//char n[13];
//strcpy(n,change_speed);
n[9]=toHexa((v/256)>>4);
n[10]=toHexa((v/256)&0xf);
n[11]=toHexa((v&0xff)>>4);
n[12]=toHexa((v&0xff)&0xf);
Serial.println(n);
query(n); // set new speed
}

void loop() {
// while(myserial.available()) Serial.write(myserial.read());
delay(1000);

query(start);
delay(10000);

//delay(5000);
for(long v=1000; v<16000; v+=1000) {setSpeed(v); delay(5000); }

query(stop);
delay(10000);
}

void transmit(String msg) {
// activate DRIVER
digitalWrite(9,HIGH); digitalWrite(9,HIGH);
delay(50);
myserial.print(msg);
delay(1);
digitalWrite(9,LOW); digitalWrite(9,LOW);
}

char hexa(char byte) { // return hexa value of that ASCII char
if(byte<='9') return byte & 0x0f;
if(byte<='F') return (byte & 0x0f) + 9; // A=0x41 --> 0x0a
}

char toHexa(int i) {
if(i<10) return 0x30 | i;
return 0x41 + i - 10;
}

char crc(char* buffer) {
int l=strlen(buffer);
int i=1;
int chk=0;
while(i<l) { Serial.print(hexa(buffer)<<4|hexa(buffer[i+1]),HEX); chk+= ( hexa(buffer)<<4|hexa(buffer[i+1]) ); i+=2; Serial.print(" ");}
Serial.print(":"); Serial.println(chk,HEX);
Serial.println(0x100-chk,HEX);
return (0x100-chk) & 0xff;
}

void query(char* cmd) {
char lrc = crc(cmd);
String msg = cmd;
msg+=toHexa((lrc&0xf0)>>4);
msg+=toHexa(lrc&0x0f);
msg+="\r\n";
Serial.print(msg);
transmit(msg);
}

Some helpful calculation formulas for choosing your 3-phase motor ...

http://www.generatorjoe.net/html/motorformula.html

Good job so far ... But, I'm not encouraging you into this direction ... cause there are thousand of VFD models around the world ... Each VFD manufacturer has his own internal FW addresses and registers inside the VFD to accept commands from his OWN EQUIPMENTS ... this is not a standard parameters to work with for all kinds and types so to be compatible for SimTools for everyone .

" They make there own keys " =>"As we do ours"

in my opinion using rs-485 is way more faulty than using conventional digital IO + analog set point in controlling VFD speed. feedback from sensors may be tricky since by using your own controller on the arduino you will need to measure process variables with the arduino and signal conditioning should be done by yourself,

Exactly ... and that's why the opto-coupler solution is provided ... It treats the VFD as if it is an H-bridge " a 3-phase H-bridge" .

Plus ... Here is another version for the Opto-coupler PCI Shield that is arranged to accept the Arduino UNO board and gives a 3 VFD's/motors output using the SMC3 Arduino 3DOF Motor Driver and Windows Utilities F/W ...

This is awesome! I'll get back to you asap. Nice one.

Hi,

I've probably a noob question...
Since I can't get any decent DC motor here I'm moving to AC motor and I don't know much about AC equipments my question is:

Can it be done with "Arduino+PLC+Contactor+AC motor" instead of "Arduino+homemade AC coupler+VFD+AC motor" ?


Thanks

Hi Guys!
Hello Speedy!
Speedy, I found you on this forum!
We communicate in Russian forum X-SIM for Russia!
Glad to see you and your success!
I have 2DOF on induction motors and frequency converter.
Other management:
+ 10V - Full motor speed in a clockwise direction
0V - the engine is not running
-10V - Full speed counterclockwise.
Are there converters for such systems?

I think you need a signal conditioner like this one here:

Yes, that's right. But instead of the potentiometer, the data from the game. What is the Converter on the video?

Hello Alex36 ...
Yes ... you mean Mal4x.ru ... Yes I remember and sorry for not being there for a while since the english translator is missing up with the whole page and couldn't keep up with it ...

As you can see by this thread now we www.xsimulator.net community have managed to gain a perfect control to ANY 3-phase motor using the CHEAPEST CATEGORY of any VFD type .... plus DIY MAKING the EASIEST and MOST ACCURATE way of signal conversion to suit ANY AC simulator motion requirements ... it is very stable with perfect resolution .

So asking for -10 0 10 SERVO converter is for me like asking for a square wheel for a car ... or promoting for extremely expensive idea like @Mmcool where the cost of the equipments plus the poor next door availability where it depends on one man will certainly overload your project .


My advice is ... Keep it simple and use any VFD with the 0-10v provided simple circuit .

Thanks .

The Arduino is a PLC ... so only with a contactor you have a fixed frequency the same as the input ... you'll never get the frequency changing the magnetic field speed inside the motor unless you use a VFD ... you have to use a VFD of any type any cheap model that has the same power rating as the motor ...

just pick the cheapest one that suits you with the same Hp as your motor and post its model here and I'll show you how ... If it is still not clear by now.

Thank you for this thread. I have been digging this forum almost night and day recently. I will use the Durapulse GS3 drive, with Arduino and 43A board (flexible). I have a question, to make sure I'm not making a mistake on a motor purchase. Everything looks good to me, but please tell me if I'm wrong.

Here are a couple from inverterdrive :
£69.00
TEC Electric – IE2 0.75kW (1HP) 4 Pole AC Induction Motor 230V or 400V B34
TEC Electric - 0.75kW 3ph 4 Pole High Efficiency Foot and Face Mounting (B34) 80 Frame AC Motor for 230V or 400V 3 phase supply. Inverter Rated for use with a Variable Frequency Inverter Drive having 1ph or 3ph input and 3ph output, or a fixed frequency mains supply at 50Hz.

Fixed mains supply output: 0.75kW (1HP) x 1410RPM at 230V or 400V x 50Hz 3ph.
Inverter Supply Output: 20:1 Speed Control range from 141RPM to 2820RPM for 5Hz to 70Hz control, with suitable de-rating at the lower speeds.

Full Load Current - 3.10A at 230V, or 1.79A at 400V.
Power Factor is 0.76 when mains connected at 50Hz.
Efficiency is 79.6%

160mm Wide x 290mm Long x 213mm high overall in its IP55 enclosure.
Foot mount on 10mm holes at 125mm wide x 100mm centres 50mm back from the shaft shoulder.
Face mount on M6 tapped holes at 100mm PCD with 80mm diameter spigot in the 120mm diameter flange.
Shaft is 19mm dia x 40mm with 6mm wide key.
Weight is 11.1kg.

Rated at 40C Ambient.
Ventilation space required at rear cooling air intake.
Thermistor for over-temperature protection.
Manufacturer Part Number is 0.7543TECAB34-IE2. Previous Part Number was - TECA2-802-4-B34

For Variable Speed use:-
Part Time Output when Inverter powered is...
2.54Nm - 0.75kW ( 1.01HP) x 2820 RPM at 100 Hz
5.08Nm - 0.75kW ( 1.01HP) x 1410 RPM at 50 Hz
5.08Nm -0.375kW ( 0.50HP) x 705 RPM at 25 Hz
5.08Nm - 0.075kW (0.10HP) x 141 RPM at 5 Hz
Continuous Output when Inverter powered is...
3.6Nm - 0.75kW (1HP) x 1974RPM at 70Hz
5.08Nm -0.75kW ( 1.01HP) x 1410 RPM at 50 Hz
4.32Nm - 0.32kW ( 0.43HP) x 705 RPM at 25 Hz
2.54Nm - 0.0375kW (0.05HP) x 141 RPM at 5 Hz

and the other is very similar: £69.00 TEC IE2 0.75kW (1HP) 4 Pole 230V/400V 3ph B14 Face Mount AC Motor
Model: TECA2-802-4-B14 Order Code: 22096

The prices a really low, so I'm thinking it' s too good to be true.
Also there is this ebay motor, but in 1.5 HP running at 1hp:

General purpose,AC Motor, 1-1/2HP, 1725RPM, 3PH/60HZ, 208-230V/460V, 56C/ TEFC, F Insulation (for inverter duty), with removable foot, 1.15 Service Factor, Rolled Steel Frame, Reversible Rotation, 10:1 Variable Torque Rating, 2:1 Constant torque Rating.

Thanks again!
Greg
USA

That Dude There,
If you are going the AC route, you "must" consider "Inverter Duty" AC Motors. Regular motors will "not" hold up long due to the massive amounts for forward/reverse that you have with motion.
Regular AC motors are NOT designed to handle the "heat" associated with constant motion.

Tom

Yes that motor pulled up when searching "inverter dudy" ac motors. It's not listed on details, so I would say it's a question mark on if it is truly inverter duty. I can't post links, but you could find their inverter duty motors fast at inverterdrive website.

I did a search on the motor you listed, and it does state "inverter duty"...............so, these are good to go with.

Good luck,

Tom

@That Dude There ... I Guess they are cheap because these are motors only without the gearbox ...

If you're going to use a 90 degree crank arm then search for a 1HP inverter duty motor with a gearbox of ratio 50:1 or higher like 60:1 or so .