Should I try to learn or find someone to hire

Projects Discussion and Showcase Robotics
1

Being completely new to Arduino and coding but having a frim grasp of the fundamentals I wanted to ask opinion if I should try and tackle my real world problem first or is it too much and I should find someone to hire if I want to realize a result in the next 30 days.. and only have a couple hours a day to tinker...

Outline of the project here, I am sure there will be additions once we realize we missed something in the real world tests..
We are using stepper motors to turn large Variable Transformers , one per phase in a 3 phase power setup. We will have some internal voltage transducers and some external amperage transducers for further down the test setup. We want to be able to set either the target voltage from phase to ground on each phase or the target amperage downstream as the load resistance varies both of course are related but its just the user experience we want to change.

Please let me know your thoughts

Project Summary

Selector Switch one when closed will put the System from Manual to Auto Mode.

Manual Mode- Priority

Manual Mode is selected by closing Selector Switch 1 open indicates Auto Mode

In manual mode the three encoders will control the three Steppers directly. When rotated in one direction stepper will move in one direction and vice versa.

When in manual mode Selector Switch 2 will choose between two step speeds Fast When closed (X Steps per increment of the encoder) and Slow when open (1 step per increment)

Limit switches will be checked after each step and when closed the respective stepper will reverse its current direction, backup three steps and blink 0000 on the respective Segment Screens (1+4,2+5,3+6) for 5 seconds before returning the screen to its prior reading.

Segment Displays 7-9 are off

In All Modes

Segment Display 1 will display Voltage read from Voltage Transducer 1

Segment Display 2 will display Voltage read from Voltage Transducer 2

Segment Display 3 will display Voltage read from Voltage Transducer 3

Segment Display 4 will display Amperage read from Current Transformer 1

Segment Display 5 will display Amperage read from Current Transformer 2

Segment Display 6 will display Amperage read from Current Transformer 3

In Auto Mode

Selector Switch 1 Open

Selector Switch 3 when closed puts the system in Voltage Select Mode and when open puts system in Amperage Select Mode

Selector switch 2 is non-functional speed will be determined by the gap between current reading and target reading see below.

In Voltage Select Mode

Encoder 1 will be used to select a voltage between 0-347 (will be limited in future) increasing by a value of 1 for each increment in the encoder. This value will be the target voltage for Stepper 1 to achieve via reading Voltage Transducer 1 This target value will be displayed on Segment Display 7

Encoder 2 will be used to select a voltage between 0-347 (will be limited in future) increasing by a value of 1 for each increment in the encoder. This value will be the target voltage for Stepper 2 to achieve via reading Voltage Transducer 1 This target value will be displayed on Segment Display 8

Encoder 3 will be used to select a voltage between 0-347 (will be limited in future) increasing by a value of 1 for each increment in the encoder. This value will be the target voltage for Stepper 3 to achieve via reading Voltage Transducer 3 This target value will be displayed on Segment Display 9

The speed of the steps should be altered based on the size of the difference between Target reading and Actual reading (Faster the larger the gap, slower the smaller the gap) Direction for now will be DIR + HIGH if lower than target and DIR + LOW if higher than target (this may need to be reversed).

Limit switches will be checked after each step and when closed the respective stepper will reverse its current direction, backup three steps and blink 0000 on the respective Segment Screen (7-9) for 5 seconds before returning the screen to its prior reading the target for the corresponding Stepper will be updated to the actual reading after reversing 3 steps

In Amperage Mode Selector Switch 3 open

Same as Above however the targets are Amps from 0-6000 in increments of 10 per encoder step (this will be limited in future) these targets are displayed one the same Segment displays as the voltage targets were in Voltage mode. The comparison in this mode will be between targets and reading from Current Transformers 1-3

Hardware Setup

Arduino Mega 2560 R3

2x Channel I2C 4-20mA Current Receiver with I2C Interface MCP3428

Encoders1-3 KY-040

Segment Displays 1-9 .36 Inch 3.3~5.5V LED 4-Digit Adjustable Brightness Display Module for Arduino Red Light

Voltage Transducers # VADT500-42-24

Stepper Controllers EM542S

Current Transducers MGT-0420

Hooked up to

AccuCT-5170R-5000-333mv

Proposed pinout

Arduino Mega
Pin Pin Description Protocol Use
20 SDA I2c 4-20MA to I2C boards x2
21 SCL I2c 4-20MA to I2C boards x2
3 Digital Hi/Low Stepper 1 PUL +
4 Digital Hi/Low Stepper 1 DIR +
4 Digital Hi/Low Stepper 2 PUL +
5 Digital Hi/Low Stepper 2 DIR +
6 Digital Hi/Low Stepper 3 PUL +
7 Digital Hi/Low Stepper 3 DIR +
8 Digital Hi/Low Limit switches Stepper 1
9 Digital Hi/Low Limit Switches Stepper 2
10 Digital Hi/Low Limit Switches Stepper 3
11 Digital CLk Segment Display 1 Clk
12 Digital Dio Segment Display 1 Dio
13 Digital CLk Segment Display 2 Clk
14 Digital Dio Segment Display 2 Dio
15 Digital CLk Segment Display 3 Clk
16 Digital Dio Segment Display 3 Dio
17 Digital Clk Encoder 1 Clk
18 Digital DT Encoder 1 DT
19 Digital Clk Encoder 2 Clk
22 Digital DT Encoder 2 DT
23 Digital Clk Encoder 3 Clk
24 Digital DT Encoder 3 DT
25 Digital Hi/Low Selector switch 1 Manual / Auto Mode
26 Digital Hi /Low Selector Switch 2 Fast / Slow Steps
27 Digital Hi Low Selector Switch 3 Amperage / Voltage
28 Digital CLk Segment Display 4 Clk
29 Digital Dio Segment Display 4 Dio
30 Digital CLk Segment Display 5 Clk
31 Digital Dio Segment Display 5 Dio
32 Digital CLk Segment Display 6 Clk
33 Digital Dio Segment Display 6 Dio
34 Digital CLk Segment Display 7 Clk
35 Digital Dio Segment Display 7 Dio
36 Digital CLk Segment Display 8 Clk
37 Digital Dio Segment Display 8 Dio
38 Digital CLk Segment Display 9 Clk
39 Digital Dio Segment Display 9 Dio
I2C Boards
1 Voltage Transducer 1
2 Voltage Transducer 2
3 Voltage Transducer 3
4
5 Current Transformer 1
6 Current Transformer 2
7 Current Transformer 3
8

Thoughts?

2

You are likely talking about a year's time to get it working the way you want. If you hire someone, how will they be able to test each step, unless you supply the test equipment and the components.
What is the real project. The three-phase transformers I have seen are all connected together so a central shaft moves the tap on all three transformers at once.
Do you have any means to keep the phases of each transformer in alignment?
Paul

3

HI Paul , actually this was one of those central shaft ones now split into three stacks. Our issue was the phases are imbalanced partially because of the source and the load during testing. Being able to adjust each phase was the idea to balance them.
A year wow , I have a little more confidence in my abilities than perhaps I should..

4

Perhaps you should consider switching capacitors to adjust the phase. What standard are you using to monitor the phase of each transformer output? Or are just comparing one to another?
Paul

5

Hi again Paul the end result is to pass for example 4000A through say 8 x 1000Kcmil cables per phase all shorted to ground. the idea is to adjust it to be 4000A per phase as we do not have control of all the variables ie resistance of cables vary , lengths are not exact. Inbound is already imbalanced... we want to do a heat run test at a steady 4000A across each phase.

6

Hire someone. Software is hard and takes a lot longer than you expect. You have no chance of getting this done in a month. Having a novice try it with two hours a day to spend is beyond silly.

How safe is all this? Those currents are scary high. Could bugs in the software cause serious damage/fires/explosions?

1 Like
7

Well, unless you have some magic to delay the magnetic flux from one part of a transformer to another, there is no way you will change the voltage/current phase ratio with a transformer. All you are proposing is to change the AC voltage of one phase or the other, not the voltage/current phase. Neither will three transformers change the phases of three phase power.
Talk to your local power company, unless you are the power company, and find out how they correct the phase differences on their distribution lines.
Paul

8

Thanks Paul for the input I will ask the guys on my end there thoughts .
73

9

Hi Bill these are high currents but voltages are low so yes fire would be a concern but these are fully witnessed tests and the whole system has multiple e stops and disconnects so not a huge concern.

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