Hi Craig, is it acceptable to only measure the voltage from the internal capacitors and look at the rate of capacitor charge or would we have to measure accumulator voltage as well? Thanks for your help
Hi Craig, great video presentation on PRE and DIS charge requirements for the 2020 FS Rules. I'm a member of Newcastle Racing's Formula Student Team, working on the Team's high voltage system and wondered whether I could e-mail yourself with regards to a couple of questions I have about the rule definitions outlined within the presentation. Cheers.
Thanks James. I appreciate the feedback.I'll be adding another presentation tonight about BSPD and the implications of the SCS rules. It is something that very few teams comply with. I want to make sure that teams don't get caught out if scrutineers/events start to police this more robustly.
Hello from New Zealand. What if you have two contacters positive and negative at the batteries in the back of the car and a third one acting on the precharge circuit that's up the front with the inverter?
Sorry for the delay in replying. I'm not sure what your suggested arrangement is. There are allowable architectures where the pre-charge resistor is outside of the accumulator, but you must obey the golden rule: there must be no unswitched HV outside of the accumulator. Putting the Pre-charge circuit inside the accumulator container is the most obvious way of complying with the rules. In my opinion it would be the most sensible solution which also reduces the wiring for the TSAL health monitoring.
I assume that you mean the AIRs? Golden rule: there must be no unswitched HV outside of the accumulator housing. Both poles of the accumulator must be switched by AIRs. Rules say: EV5.6.1 At least two AIRs must be fitted inside each TSAC. EV5.6.2 The AIRs must open both poles of the TS accumulator. Does that answer your question?
Hi Craig, can we use a simple microcontroller to regulate the closing and opening of the AIRS? We will still measure the two voltages and compare them via comperator then on the low voltage side the AIRS have to be regulated and we dont see any other way of doing this. The rules are not so clear about how much software there is involved.
I see no reason why you cannot use a microcontroller to control the pre-charge sequence, but you must use conventional normally-open mechanical relays as the final element in the shutdown circuit (EV 5.7.2). When you have designed the circuit ask yourself whether it will fail to a safe state on loss of module power, burned out relay coil etc, and ask yourself what the impact and mitigations would be if you have a stuck output relay (welded contact). [Read the TSAL rules]
@@craiguk62 i m a member of the Formula Cruisers team the hague, because the precharger/discharge pcb needs to be in the accumulator container, the microcontroller could malfunction because of the EMC in the ACC container? For now i have designed a logic gate circuit to hardwire the signal output of the comperator. Then i can control the sequence of the closing/opening of the AIRS too if i also use RC network to delay the sequence. (i ll use cmos logic). My question is, do you think the EMC is could make the microcontroller malfunction?
@@jerardterian3879 that is a very open-ended question Jerard. It's all down to good practice, careful design, neat and well thought-out cable runs, screening and filtering. Only testing will confirm but there is no reason why it should not work.
@@craiguk62 thank you sir , we are first year EV team from india trying our way out in current situation . Our guys are from mechanical engineering and your video was lot helpful to understand the concepts . Will be looking forward to have your video on the topic . Thanks a lot sir .
Great videos! Really very helpful to new teams and I'm sure to established ones as well.
These videos are really helpful! Thanks for taking the time to make them.
Hi Craig, is it acceptable to only measure the voltage from the internal capacitors and look at the rate of capacitor charge or would we have to measure accumulator voltage as well?
Thanks for your help
Hi Craig, great video presentation on PRE and DIS charge requirements for the 2020 FS Rules. I'm a member of Newcastle Racing's Formula Student Team, working on the Team's high voltage system and wondered whether I could e-mail yourself with regards to a couple of questions I have about the rule definitions outlined within the presentation. Cheers.
Thanks James. I appreciate the feedback.I'll be adding another presentation tonight about BSPD and the implications of the SCS rules. It is something that very few teams comply with. I want to make sure that teams don't get caught out if scrutineers/events start to police this more robustly.
feel free to email me using the email on last page of the videos
Hello from New Zealand. What if you have two contacters positive and negative at the batteries in the back of the car and a third one acting on the precharge circuit that's up the front with the inverter?
Sorry for the delay in replying.
I'm not sure what your suggested arrangement is. There are allowable architectures where the pre-charge resistor is outside of the accumulator, but you must obey the golden rule: there must be no unswitched HV outside of the accumulator. Putting the Pre-charge circuit inside the accumulator container is the most obvious way of complying with the rules. In my opinion it would be the most sensible solution which also reduces the wiring for the TSAL health monitoring.
Hi Craig - is it necessary to have a contactor on both legs of the traction motor
I assume that you mean the AIRs?
Golden rule: there must be no unswitched HV outside of the accumulator housing.
Both poles of the accumulator must be switched by AIRs.
Rules say:
EV5.6.1 At least two AIRs must be fitted inside each TSAC.
EV5.6.2 The AIRs must open both poles of the TS accumulator.
Does that answer your question?
Hi Craig, can we use a simple microcontroller to regulate the closing and opening of the AIRS? We will still measure the two voltages and compare them via comperator then on the low voltage side the AIRS have to be regulated and we dont see any other way of doing this. The rules are not so clear about how much software there is involved.
I see no reason why you cannot use a microcontroller to control the pre-charge sequence, but you must use conventional normally-open mechanical relays as the final element in the shutdown circuit (EV 5.7.2). When you have designed the circuit ask yourself whether it will fail to a safe state on loss of module power, burned out relay coil etc, and ask yourself what the impact and mitigations would be if you have a stuck output relay (welded contact). [Read the TSAL rules]
Could you also introduce yourself by team name. Thanks.
@@craiguk62 i m a member of the Formula Cruisers team the hague, because the precharger/discharge pcb needs to be in the accumulator container, the microcontroller could malfunction because of the EMC in the ACC container? For now i have designed a logic gate circuit to hardwire the signal output of the comperator. Then i can control the sequence of the closing/opening of the AIRS too if i also use RC network to delay the sequence. (i ll use cmos logic). My question is, do you think the EMC is could make the microcontroller malfunction?
@@jerardterian3879 that is a very open-ended question Jerard. It's all down to good practice, careful design, neat and well thought-out cable runs, screening and filtering. Only testing will confirm but there is no reason why it should not work.
So educative sir
Sir , Please make detail video on Accumulator Design .
Its not my area of expertise but I will try.
@@craiguk62 thank you sir , we are first year EV team from india trying our way out in current situation . Our guys are from mechanical engineering and your video was lot helpful to understand the concepts . Will be looking forward to have your video on the topic . Thanks a lot sir .