openinverter forum

Hi There.

I managed to acquire two 1PV5131-4WS52-ZW11 Siemen's Motors a few years ago and I tested them with Johanne's Openinverter and a Gen2 Prius inverter with total success.
However I did not read the label correctly and mistook 'Encoder No' to mean the 'Encoder Number'. The 12 pin circular connector also through me by displaying 12 pins. I confirmed my suspicions by opening the connector and realising that the wiring was for KTY temp sensors but no encoder cabling.

As getting an genuine encoder for these babies will probably be near impossible, I wondered how feasible it would be to make up something to give the necessary feedback. The Motors look like they would be good in my acquired Smart car.

Any advice gratefully received. Keep up the great work Johannes.

Regards
Stephen

Stephen Darbey wrote: ↑Tue Nov 23, 2021 1:41 pm As getting an genuine encoder for these babies will probably be near impossible, I wondered how feasible it would be to make up something to give the necessary feedback. The Motors look like they would be good in my acquired Smart car.

Encoders are not strictly necessary for induction motors. If you are doing FOC control then it needs a bit of help at low speed so they put an encoder on the motor. If the inverter is doing V/Hz control then no encoder is needed. Induction motors will basically spin however fast you ask them to spin so control is quite easy. It is only once you want to start doing field weakening that you'd need to start getting fancy. By the point that field weakening is needed the motor controller is well into the point where an encoder is no longer necessary for position feedback. At that point current sensors can be used instead.

But, I didn't write the OpenInverter firmware and I don't know how it would deal with a motor that has no encoder. In theory, from an electrical standpoint, it is entirely possible to control an induction motor without ever having an encoder. But, the firmware would have to be OK with that.

Simple V/Hz control might work for a drilling machine, a car is going to be undriveable. Yes, the firmware can *spin* a motor with no encoder but it cannot do torque control.
Apparently there are sensorless algorithms that need to know a few electrical parameters and then recover rotor position from measured currents. At least at higher speed. But that is not implemented in openinverter firmware, it just requires position feedback. If you need it for low speed operation you might as well use it always.

Can a sin/cos encoder be also used on an induction motor in openinverter? I used sin/cos encoder on a permanent magnet motor with openinverter FOC firmware with great success. These encoders are very slim and easy to attach to a motor and there are different variants of them at a very affordable price.

m.art.y wrote: ↑Wed Nov 24, 2021 10:43 am Can a sin/cos encoder be also used on an induction motor in openinverter? I used sin/cos encoder on a permanent magnet motor with openinverter FOC firmware with great success. These encoders are very slim and easy to attach to a motor and there are different variants of them at a very affordable price.

Yes

Thanks Guys for the feedback,
I really appreciate it. As the aforementioned motor is a bit under powered, I would definitely require some sort of encoder to gain the max torque etc.
So I guess I should start experimenting, It must be really small as I only have about three or four cm to play with, before it touches the rear coil spring. The shaft will have to be cut back also.
Thanks again
Stephen

HI. I bought myself a type of such an encoder, maybe it will suit you too

https://russian.alibaba.com/product-det ... 54276.html

They are also put in place of a regular bearing, they are of different sizes

Thanks Yaroslav.

Yes Indeed, The enclosed encoder in the bearing would be best, and just feed the harness up to the circular connector, however I am reluctant to open rear of motor as it is a water cooled motor and don't want to upset any seals etc. I also would have to get exact matching size which may or not be available. But no doubt about it it would be best and would solve my lack of space problem.

Thanks again
Stephen

Hi Stephen, did you order the encoder plug and caps for the phase wire inputs for this motor yet?

I've been looking on Radionics and there are several M23 12 pin connectors that **could** work, but hard to tell if they're a match.

Mine is a 1PV5135, but I'm sure the connectors should be the same.

Thanks!

Hugh

For anybody looking for an encoder plug for the Siemens 1PV5135, I ordered this one https://ie.rs-online.com/web/p/industri ... ption_Link from Radionics, and it fits.