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Discussion Starter #21
Given that there are separate left and right motors, I think it would be difficult to build a sufficiently capable control system, unless you have substantial ability to add programmed functionality to the motor controllers. For example, Curtis Instruments has controllers which are designed to be able to communicate and to coordinate control of two motors, so one takes the analog accelerator pedal input and serves as the control master, while the other controller gets its commands from the master and acts as a slave; each controller powers a motor. The intelligence needs to be somewhere, and if that's not the motor controllers I think you need a VMU.

Hi Brian, The Sevcon inverters are currently programmed to work in the same way, ie one is the master and the other is the slave. The master would have been receiving CAN messages from the VCU that it would decode and share with the slave inverter. Problem now is that I do not have the VCU so I will have to take the output from the throttle pedal, convert it to CAN messages that the Master inverter would understand. I would think you would have to do the same for any leaf inverter for example, so its possible, question is if i can do it with my limited knowledge. I have heard its possible to do this with Ardunio, and there is a lot of info on Ardunio on the net...
 

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Hi Brian, The Sevcon inverters are currently programmed to work in the same way, ie one is the master and the other is the slave. The master would have been receiving CAN messages from the VCU that it would decode and share with the slave inverter. Problem now is that I do not have the VCU so I will have to take the output from the throttle pedal, convert it to CAN messages that the Master inverter would understand. I would think you would have to do the same for any leaf inverter for example, so its possible, question is if i can do it with my limited knowledge. I have heard its possible to do this with Ardunio, and there is a lot of info on Ardunio on the net...
For the amount of effort and how little you paid for the drive package, this makes a lot of sense despite any issues with evtv.

http://store.evtv.me/proddetail.php?prod=gevcu6
 

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The Sevcon inverters are currently programmed to work in the same way, ie one is the master and the other is the slave. The master would have been receiving CAN messages from the VCU that it would decode and share with the slave inverter.
It's good to hear that you're not missing critical logic. Now it would help to know what else the VCU does...

Problem now is that I do not have the VCU so I will have to take the output from the throttle pedal, convert it to CAN messages that the Master inverter would understand. I would think you would have to do the same for any leaf inverter for example, so its possible, question is if i can do it with my limited knowledge. I have heard its possible to do this with Ardunio, and there is a lot of info on Ardunio on the net...
Although working in an unfamiliar technology is a challenge, I think you have a similar challenge whether you build up an external device (Ardunio or otherwise) or you modify the Sevcon programming. It might be easier to manage if your work is only in the external device, isolated from the Sevcon programming; you can also be sure that a suitable external device can do anything the VCU did, but it's not obvious that the Sevcon controllers will have all desired input and output capabilities.
 

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Discussion Starter #24
Hi All, Been a while since i last posted. Having a child and building a workshop got in the way. Back to the project now.

I have taken the motors and built a temporary jig to hold the motors, they will be clamped to the bench which is pretty big and heavy.

The Sevon controller has the functionality to act as a master/slave, but it looks like the controllers were controlled independently by the old VMU. As the 1st phase of the test i'm going to try and get one motor to work by sending the correct signals to one sevcon. If that doesnt work then i need to get ahold of the DVT software (have the IXXAT USB to CAN already) and understand how the inverter has been programmed.

To get one sevcon working i'll need to build the pre-charge power circuit, 12v circuit, add F/N/D selector, accelerator pedal, and find 300V.

I have 150V in batteries from other projects, need to find another 150V!

Anyway, promise the posts will be more regular from now on!
 

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