FISHERPAYKEL washing machine motor HOW CAN I INCREASE SPEED ? - Page 1
Forum section: electronics / beginners

author: elektronJack
author_rank: Contributor
timestamp: January 28, 2020, 10:33:35 am
content: 6 marI was unable to modify by adding to the foot of this posting, so i have added here.No one has really answered yet, the questions i have asked.There are three sets of circuits, all identical, except for the arduino pins which turn thePC 817 optocouplers off and on.Red circuit uses Arduino pin 7 for high side and 6 for low side.Blue circuit, pins 5 and 4 respectively.Yellow circuit, pins 3 and 2 respectively.The hall sensors of the motor are connected to Arduino pins 8,9 and 10, and the hall sensor is powered from one of the Arduino 5v pins.There is also a potentiometer, which is supposed to control the motor speed, connected to another Arduino 5v pin.Adjusting the pot appears to have little effect. Increasing the voltage from one12 v 5AH battery to two batteries appears to increase speed only very slightly.I suspect that the maximum current needed to the motor should not be too much .I say this as the wires connecting the controller to the motor in the washing machine, from which the motor was taken, are not very thick.Voltages in my circuits:Voohs VoolsRed 11.36 6.13Blue 9.82 6.26Yellow 12.88 6.2My question is, how can I increase the speed of rotation? My aim is for at least 5 revolutions per second.Attached is partial circuit diagram.Evidently it's not permitted to attach a video Mp4 of the motor rotating or arduino code which I intended to do.+++----++++++++Evidently the manufacturer uses igbt s. Photos of the control board attached((((((((( addditional post. )))))))))11 may 2021does anyone know a complete driver capable of 100v dc or higher. i have usedWS55-220 successfully, without hall sensors, operating at a max inputof 50v dc.the rpm is too slow.to suggest i hack the original motor controller is beyond my knowledgealthough very interesting.

author: Zero999
author_rank: Super Contributor
timestamp: January 28, 2020, 11:29:49 am
content: Don't expect much speed from a motor running at a much lower voltage, than its rating.You should use MOSFETs for such low voltages, rather than IGBTs, which have a very high voltage drop.The high side IGBTs need a separate gate drive power supply, to enable the gate voltage to exceed the power supply voltage rail.Use proper MOSFET driver ICs. The IGBTs will take an eternity to turn off with 221k pull-down resistors. A simple opto-coupler such as the PC817 is not going to be able to charge/discharge the gate capacitance quickly enough. You need a gate driver, which can supply high current spikes.

author: elektronJack
author_rank: Contributor
timestamp: March 04, 2020, 01:04:03 pm
content: basic circuit has been changed to include a bootstrap on the high side and a ULN 2003 on the low sideAdditional images and arduino code added

author: Zero999
author_rank: Super Contributor
timestamp: March 04, 2020, 01:24:07 pm
content: How much current does it require? The ULN2003A is only rated to 500mA.Why not use a proper H-bridge IC such as the SN754410, DRV8313, BD6236 etc.?http://www.ti.com/lit/ds/symlink/sn754410.pdfhttp://www.ti.com/lit/ds/slvsba5b/slvsba5b.pdfhttp://www.farnell.com/datasheets/2097985.pdf?_ga=2.209126548.76887383.1583327895-2127120132.1578504493&_gac=1.6497926.1583327895.EAIaIQobChMIqOK-_fOA6AIVBbDtCh2KuwqjEAAYAiAAEgKs5_D_BwE

author: grifftech
author_rank: Frequent Contributor
timestamp: March 04, 2020, 04:12:26 pm
content: that motor is a bldc, the uc on the inverter board is programmed to have a maximum output frequency, and thus motor speedyou could also use a gearbox to increase the rpms

author: brucehoult
author_rank: Super Contributor
timestamp: March 04, 2020, 07:52:51 pm
content: Surely you mean "AVR" not "Arduino"?

author: elektronJack
author_rank: Contributor
timestamp: March 04, 2020, 11:41:41 pm
content: Arduino is correct.

author: elektronJack
author_rank: Contributor
timestamp: March 04, 2020, 11:47:23 pm
content: The present speed is only approx 0.75 rps

author: tautech
author_rank: Super Contributor
timestamp: March 05, 2020, 12:59:54 am
content: Quote from: elektronJack on March 04, 2020, 11:47:23 pmNot in Spin mode.

author: twospoons
author_rank: Frequent Contributor
timestamp: March 06, 2020, 01:20:45 am
content: Either more volts, or rewind the motor with fewer turns of thicker wire.

author: brucehoult
author_rank: Super Contributor
timestamp: March 06, 2020, 01:32:30 am
content: Quote from: twospoons on March 06, 2020, 01:20:45 amThose things already do 1000 RPM in spin dry mode, no gearbox or pulleys. It's just how you drive them.

author: amyk
author_rank: Super Contributor
timestamp: March 06, 2020, 04:21:28 am
content: 5 revolutions per second? That's 300RPM, which is very low speed as far as AC motors go...

author: elektronJack
author_rank: Contributor
timestamp: March 06, 2020, 04:51:36 am
content: Yes its just how they're driven. How to drive them is my problem. I would be suprised if the voltage/current is extremely large.

author: tautech
author_rank: Super Contributor
timestamp: March 06, 2020, 05:03:49 am
content: Quote from: elektronJack on March 06, 2020, 04:51:36 amYou drive them in the same way as the controller does, reverse engineer it and scope the drive to the MOSFETs and you will have your answers.These are not toy motors and simple controllers understand this but a generally very reliable and robust K1W1 built and designed matched system.

author: Zero999
author_rank: Super Contributor
timestamp: March 06, 2020, 08:57:40 am
content: Quote from: elektronJack on March 06, 2020, 04:51:36 amIt depends on what you mean by large?The current probably isn't massive, perhaps a couple of Amps at most, as the power rating will be a few hundred Watts. If there's very little load, the current will be less.In order to get to full speed, the full mains voltage is required, which is a peak voltage of 340V, assuming 240V main. The motor generates a voltage with the same polarity as the applied voltage, as it spins. The faster it spins, the higher the voltage. Because the generated voltage is the same polarity, as the applied voltage, the current goes down, as it keeps going faster and faster. As the speed increases, there will come a point when the generated voltage matches the applied voltage, the current reduces towards zero and the motor can't spin any faster.To go faster, you need a much higher voltage. You're only driving the motor with 28V peak, which is roughly1/12of the voltage rating, so 0.75rps is roughly what you should expect.What's wrong with the original motor driver? You'd be better off hacking/repairing/replacing that, rather than trying to make your own.

author: twospoons
author_rank: Frequent Contributor
timestamp: March 10, 2020, 12:52:20 am
content: I worked for Fisher & Paykel Laundry for a couple of years. These motors were designed to run from rectified 230VAC, or about 350VDC, so each phase has quite a few turns. The resulting high back-EMF/rev is limiting your speed.To go faster, you need more volts to overcome the back EMF, or fewer turns to reduce the back EMF.The motor bridge in the washing machine was driven as a simple 6 step 3-phase system. As has been said, it will happily do 1000RPM, but it needs 350VDC to do it.As I recall the bridge was a MOSFET bridge, and the motor was capable of roughly 1kW. This was 20 years ago mind you - things may have changed a bit since then.

author: Circlotron
author_rank: Super Contributor
timestamp: March 10, 2020, 01:48:46 am
content: Get three transformers to step up the voltage between your low voltage inverter and high voltage motor. I used three 28V/240V 150VA toroids to make a coke can size permanent magnet motor go to 20,000rpm with 30VDC supply to the inverter. Without the transformers it would only go to about 2500rpm or so IIRC.

author: brucehoult
author_rank: Super Contributor
timestamp: March 10, 2020, 01:49:36 am
content: Quote from: twospoons on March 10, 2020, 12:52:20 amAhh .. good explanation of your previous good advice, which appeared without context or the logic behind it.

author: Jwillis
author_rank: Super Contributor
timestamp: March 10, 2020, 05:49:03 am
content: For high voltage motors like that you would use a Variable Frequency Drive (VFD) . Some I believe can be controlled by a MCU but which specifically I can't tell you. There are many. You would have to search for one that would suit your purposes.

author: twospoons
author_rank: Frequent Contributor
timestamp: March 10, 2020, 10:38:19 pm
content: I don't know if this is true of the motor you have, but at the time I was there work was going on around sensorless commutation by picking up the third harmonic of the drive frequency from the star point of the motor windings. Something about the pole face design could be used to create a larger 3rd harmonic, and the zero crossings were the commutation points, IIRC. The details are a bit hazy now, but I'm sure there will be research papers out on the web somewhere.Could be something fun to play with.