Search results for query: *

Appreciate that sir Do you have a view on whether the percentages relate to full scale or measured value?

Hi All This seems like quite a basic question but what is the definition of 'measuring error' for a rogowski coil power metering system For example, systems are typically stated as having 1% rated accuracy for the rogowski coil and the measuring relay. Is this 1% of the measured value, or of...

Much appreciated guys

Thanks everyone for your responses I appreciate it The vehicle is an on highway freight prime mover with traction control.

Thanks all Can anyone please describe the inertia concern in a bit more basic terms as to how it could break something (mech is not my strong suit) Cheers guys appreciate it!

Thanks Ng2020 Fundamentally the belt drive/motor isn’t rated to the max load of the transmission output. I will need to check regarding dynamic loading as you describe.

Thanks all Littleinch, so what do you think will happen when more than rated torque is applied the motor shaft while it is in the generating mode? I suppose the torque at the motor shaft is generated by the regen action of the motor, up to rated torque, and this determines the torque...

This is my main question whether the motor will be driven by the transmission torque but nothing will break… I am finding it hard to be convinced though..

Hi All We are designing a parallel hybrid vehicle which has an ICE engine driving a transmission and an electric motor coupled to the transmission output shaft. A direct torque coupling is used between the motor and transmission output shaft - the motor is basically driven via a belt drive...

Appreciate your advice Waross As I understand, spare capacity in these systems is the norm - referred to as voltage reserve. One could disconnect some elements, but I can see issues like the layout of the furnace and heat uniformity being an issue.

Thanks all - Comcokid - Really - how can excess current cause saturation? Transformers are typically allowed to drive overload currents without mention of saturation. Excess voltage or DC offset causes saturation right? Jraef - Understood the maximum current can't be greater than this number...

We are working with a heating system which controls heat delivered to resistive elements by chopping out whole cycles of the AC voltage waveform. I.e. the SCRs conduct for one cycle, then stay off for 3 cycles, and then conduct for one cycle, would represent 25% heating power. It has got me...

Thanks mate Yeah I think we could do that. We’d use 240mm2 cable lugged in parallel… for all intents it could be close to identical. Ie the cable arrangement - see the attached sketch (excuse the dodge detail, did it on my phone). 

Hi All, I need to source a 600A 5% line reactor for notching and harmonic mitigation of a 400V 550A three phase AC controller. I am in Australia, and availability of such things is very difficult. 5% line reactors are not stocked at all, and 3% reactors are stocked but only in sizes below...

Thanks jghrist. I am starting to think it's mostly about the source not being very stiff, having a relatively high secondary impedance and the very high di/dt at thyristor turn on is causing the voltage dip of the source. Perhaps there's also some capacitance and the like interacting with it. I...

Thank LionelHutz, you're right. It was a stock pic that I just stole from Google Images :) I have corrected.

Update on this guys, I checked the system out with a scope meter and I have attached an example of the rather alarming waveforms which were present. The measurement was phase to phase on a sub circuit which is fed from the main board in the facility - not on the actual SCR controller feeder -...

Thanks jraef, I can't for the life of me understand it. Even if all six of the thyristors are on simultaneously I do not see how a phase to phase short circuit could be caused, not in the same way as if the thyristors were connected in a bridge. What about a typical soft starter as an analogy...

Hi Jraef, thankyou for your reply. Are you able to please help me understand? I feel like I have thought about this in and out and I cannot conceive of how this is occurring. I understand how it could occur on a fully controlled rectifier bridge, but I can't see how that applies in this case...

Hi All We have a SCR/Thyristor heating system with a configuration shown in the attachment. The device is a phase angle controlled resistive Silicon Carbide heating controller We are seeing possible signs of line notching being caused by the controller - is this possible? I thought that line...