Chevrolet Bolt EV High Voltage Components

Chevrolet Bolt EV High Voltage Components


[Music] hello I’m professor John Kelly and this is the Weber Auto YouTube channel in this episode we are going to look at the high voltage electrical system on our 2007 Chevrolet bolt Eevee now our bolt here is brand new a year ago it only has about 30 miles on it but we have disassembled everything under the hood that can be disassembled in relation to the traction motor or the inverter the onboard charger the DC to DC converter of the junction block the air conditioning compressor the high voltage battery heater we’ve got the high voltage battery out front of the car and if you look here we’ve even got the charger poured out ours did not come with DC fast charge I’ve got DC fast charging to try to put on this to do a conversion but I’m not sure that it’ll work now if we look underneath the hood of the vehicle here and compare this to the this photograph of how it looked before we disassembled it you can see that everything is gone that it’s totally empty the radiator that was in the front here is only for the traction motor and the power electronics there is a separate cooling loop under the hood here for the battery the battery cooling is not done at all through the radiator to my surprise it only has a battery chiller through the air-conditioning system that we’ll look at in a future episode the only high-voltage component I did not remove for this episode is the heater coolant heater so while you were driving down the road if you want heat in the passenger compartment when the weather is cold this heater assembly is a high voltage heater it’s got the orange cable right here and it heats up the coolant that is circulated through the heater core up underneath the hood here so it goes into the passenger compartment into the heater core comes back out the coolant reservoir right here one of three reservoirs under the hood is just for the heater coolant so there’s a loop there and us and a little pump that pumps the heated coolant through your heater core this reservoir right here is for the battery cooling and this one right here is for the motor and electronics cooling this vehicle uses the are 1 2 3 4 YF refrigerant in its air-conditioning system and so it takes this special air conditioning recovery recycling machine as you can see in this photograph here this refrigerant is very expensive and there’s special procedures of handling that refrigerant special training just for that so the air conditioning system on this car obviously cools the air in the passenger compartment but it’s also responsible for cooling the battery whenever it’s it’s too hot whether that’s from charging or just from driving and there’s a separate battery heater that will heat it up when it’s too cold while charging all right well let’s go take a look at all these components that we’ve removed from under the hood see what they are talk about what they do see how they’re all interconnected with the big orange high-voltage wires and how they all end up connecting back to our high voltage battery ok here on the table we have the drive unit which is comprised of the electric motor the traction motor and the gear reduction unit that make up the propulsion system for the 2017 and above Chevrolet bolt evie now I will have a separate video on the disassembly and inspection and reassembly of this this drive unit is liquid cooled it has an inlet and an outlet pipe there for coolant and it just uses regular General Motors Dexcool 50/50 mix coolant the lubrication for this drive unit is automatic transmission fluid the Dexron HP fully synthetic dextran HP automatic transmission fluid and this holds 2.9 liters of this fluid also while we’re here on the motor there are two excellent society of automotive engineering technical papers that you can purchase I can’t show you these because they’re copyrighted but they have fantastic information on the design and operation of this drive unit and of the entire Chevrolet Volt evie powertrain both of these were presented in April of 2016 one of them is called the design of the Chevrolet Volt evie propulsion system the other one is called electric motor design of General Motors Chevrolet bolt electric vehicle so some great additional information if you’re looking for technical details on these on this system so this motor has is rated at 150 kilowatts which is roughly 201 horsepower it’s also rated at 360 Newton meters of torque which is approximately 266 pound feet of torque and it has a maximum rpm of 80 810 rpm which for the tire size on the bolt evie puts the maximum vehicle speed according to the limited inter motor rpm here at approximately ninety four point six miles per hour it has a seven point zero five one eight to one gear reduction unit the drive unit itself is designed so that it’s dead center in the middle of the vehicle that means the CV shafts here on each side are equal lengths and as a matter of fact they are exactly the same part number of CV shaft and that’s to eliminate torque steer upon heavy acceleration I’m going to remove these CV shafts and then we’ll we will start bringing in the rest of the electrical high voltage component that are used to control this drive unit and the rest of the high voltage system on the vehicle now this drive unit is mounted to the lower support cradle in the front of these Chevrolet bolt evie but right above that is a big steel bracket that supports all of the electronics that you see when you look under the hood so I’m going to bring that bracket over and set it here on top of the motor I’ve got these floor jacks and other stands here to help hold it in place while we build this high voltage system so this big bracket here is called the under hood cross car beam and like I said it holds all the electronics on top or above the electric motor itself okay I’ve now got the underhood cross carb beam installed besides holding the power electronics to control the drive unit it provides structural support in the front of the bowl TV to make it stronger during a collision this under hood cross car beam as you can see has several ground wires attached to it this one goes to the DC to DC converter for our 12-volt system the rest of these attached to the electric motor drive unit and the chassis of the vehicle to connect our 12 volt systems ground to the DC 2 DC converter in the end the cross car beam as well as the housing of the drive unit itself now in order to make the electric motor rotate we have what’s called a single power inverter module or spi M so I’m going to bring the spim these single power inverter module over next this is the single power inverter module or the spim as you can see it is also liquid cooled we have a low voltage connection in the front we have a power feed from an under hood junction block that connects to the high-voltage battery so we have the two wire DC coming in and then in the back here as you can see we have the three-phase electrical connection going out that will feed power to our three-phase electric motor in the drive unit this particular inverter that I have right here is one I purchased off of ebay and I’ve taken it I’ve taken the lid off of it and I will take this apart in a different video and explore what parts are inside of it but I imagine it’s just a typical inverter with the typical pieces in it I’m pretty sure it does not have a boost converter inside of it to boost the voltage up but I don’t know yet I still need to take it apart so this power single power inverter mod sits right up here on this under hood cross car beam now if you open the hood on your Chevrolet bolt Evy and look down inside you’ll be able to see the front of this single power inverter module but on top of that is another module this one right here this one is called the high power distribution module or HP DM and basically what this does is it receives power on these two big terminals right here from the high-voltage battery and then can transfer that to the inverter module here on the side with the connector it can sent it to the heater coolant heater to heat the coolant that goes into your heater core on cold days and that’s up underneath the hood there are four other connector connectors here on the side of this distribution module we have one for the air conditioning system one from the onboard charger when you plug in your external charger to the car to charge the battery one going to the battery itself for charging the battery and then one that goes to the heater that heats the coolant that goes into the battery on cold days now on the front of this there is no electrical connector but if I had one that had fast charging it would have an electrical electrical connector right here let me get one that does okay so here is a high power distribution module that has the electrical connector on the front for fast DC charging so here’s the other one out of our bolt evie that does not have the fast charging here’s one that does have the fast charging other than that externally all the connections are the same the one that has the fast charge connections if we take the lid off of this thing and look inside it actually has two additional contactors that basically connect these two big heavy terminals for your DC fast charge right through this distribution block and connect it right to the two terminals the large terminals that go to the high voltage battery to charge the battery and so it bypasses everything else and just goes right through to for a fast charge on that battery all right now I found this high power distribution module on on ebay for the fast charge option and so I’m going to put that back on our bolt Eevee over here and attempt with additional other pieces that are required to convert ours to fast charge I’ve heard from some people that have tried this and said they could not make it work so I don’t know if I will be able to either but we’re going to try it so the high power distribution module the HP DM goes right up here on top of the single power inverter module so now when you open the hood and look you can see the top of this high power distribution module sitting right there so we’ve got two of the four modules installed on this cross under hood cross car beam right above the electric motor now the next module that goes down on the this beam here is the onboard charger and when they say onboard charger that means when you plug in your j17 72 charge cable whether it be on 120 volts or 208 or 240 volts that’s an AC voltage it has to be converted to DC to charge the DC battery but all of those voltages are lower than this battery’s 350 to 400 volt range and so then they also have to step up the voltage to be a high enough voltage to actually charge that battery so the onboard charging module the OB CM does a lot and it is also liquid cooled let me get it so this is the onboard charging module as you can see it is also liquid-cooled and then here on the driver’s side it has three electrical connectors this bottom one is AC voltage in from the charge receptacle this black one is low-voltage for control and this top one here is DC output that then would go to our under hood distribution module and then go charge the battery the high voltage battery on the smaller of the two orange connectors on the battery so now I’m going to put this on board charging module up here on the under hood cross carbine okay it’s fairly heavy awkward angle so this is our on board charging module it bolts to the Underdark under hood cross car beam and has electrical connectors there on the driver’s side okay the next module that goes on that you can see under the hood directly is the accessory power module the APM and basically this is a DC to DC converter and basically what this does is it takes high-voltage from the battery which could be upwards of 400 volts and it has to step it down and output roughly 14 volts 13 and a half 14 volts to charge the 12-volt battery and the 12-volt system on the rest of the vehicle because it’s that 12-volt system that controls the high voltage system on these on all of these hybrid and electric vehicles so we have on this end here a 14 volt output this is our the equivalent of the ground that would then go to the battery negative so this is go to battery positive this is go to battery negative through the on car cables there as you can see here it is also liquid cooled so a lot of liquid cooling going on here this accessory power module just sits right up here right there I’ll hold that in place with a couple of bolts okay these are the four major components that you can see under the hood of your Chevrolet bull when you open it we’ve got the high Power Distribution module right here underneath that is the single power inverter module that drives the drive unit electric motor down below we have our our accessory power module the APM which is a DC to DC converter and right below that we have our onboard charger module to take the wall voltage when you plug in your vehicle to charge it and change it to a high voltage DC to charge the battery now we’ve got two other high voltage electrical components to bring in and then we can start connecting the wires on these to show how they are all electrically connected together okay the next high voltage component to add to our workbench mock-up here of the bull DV powertrain is the air conditioning compressor module the AC CM so it has a two wire DC high voltage electrical connector that comes in to the module end of the electric air conditioning compressor where it has its own inverter it’s going to take this DC voltage and change it into a three-phase AC voltage to drive a variable speed air conditioning compressor this compressor of course is used to cool the passenger compartment but it is also used to cool the high voltage battery there is no radiator for the cooling of the battery it only uses what’s called a chiller where the air conditioning system has this little mini evaporator that the coolant for the battery runs through where removes the heat from the coolant and then runs that out to the air conditioning condenser in front of the vehicle and radiates that eat away so this a air-conditioning compressor module sits right on the drive unit right in front of the drive unit here I’m on a stud and a couple of bolts holding it in place okay so now we’ve got our air conditioning compressor module with its high voltage connection that’s going to stick out the back over here that leaves us with one more high voltage component that we need to bring in for the full evie system all right this last component here is the battery coolant heater they call it the rechargeable energy storage system heater so they don’t call it a battery they call it our ESS the rechargeable energy storage system and so it has two coolant lines right here and right here that connect it has a high voltage connection right here there’s a big heating element inside there’s a temperature sensor right there and some ground wires connected to it and this is also eventually connected back here to this high power distribution module but through the big harness and so this sits over here in back of the drive unit so it’s going to sit right right about here and it’s bolted to hold it to the frame to start connecting all of these components together we have one three wire wire harness right here and this is for the three phase voltage control of the drive unit and so this upper end right here is going to connect to the single power inverter module the lower connector here is going to connect to the drive unit in the back so let’s hook this up okay to connect it got a couple of studs on the inverter side and three bolts and then here on the motor side we also have three more bolts by the way none of these systems have live voltage on them the battery that has all the powers over next to the bolt evie and here in the shop all of these wires even though they’re orange and I’m not using any personal protective equipment on them there’s no voltage on them there’s no danger when you’re when you’ve got these components off to the side and they’ve already been verified that there’s no voltage on them okay so here on the back of the single power inverter module we have three-phase cables the UV and W cables that come down to our drive unit electrical connector and they bolt in place they have nice weather tight seals and that this is the only these are the only three phase AC voltage cables that you’ll see on this vehicle all these others are two wire DC voltage so if you see three wires right next to each other like that going to a motor those are AC voltage wires if you just see two wires next to each other like these then those are high voltage DC connections okay the next electrical harness to connect up is a u-shaped great big thick wire heavy gauge wire electrical connectors and what this does is this will connect the high power distribution block electrical connector down to the power inverter module electrical connector and they just have a little latch lever on the side so all that does once again is connect the distribution module to the power inverter giving the power inverter DC power from the high-voltage battery okay the next big wire harness to connect is the wire harness that connects at the battery itself to provide power to the inverter it also has two additional small electrical connectors down on the bottom one that goes to the battery heater one that goes to the charge port on the battery itself the smaller of the two electrical connectors for the DC charge the 7.2 kilowatt hour AC charger that’s connected to the onboard charging module here under the hood so here on the back of the power inverter module we have a great big electrical connector that’s going to come in right there snap into place it also has two small electrical connectors right here one of them or they both go to the distribution module right up here the upper electrical connector is what connects to the battery heater down below here so I will connect the harness connector underneath the vehicle to the battery heater this second connector up here the lower of the two then goes to the battery charger the AC battery charger connection on the high voltage battery so under the car we only have two electrical connectors the great big one that’s for feeding power to the power inverter module and regenerative braking power back to the battery well as you drive this also is the practical connector that is used when you connect up the DC fast charge connector to the vehicle it will charge directly through this large electrical connector rather than the small electrical connector back here this one is only for when you plug in your J 17:70 to charge connector the other one is the the combo the the J 1772 combo connector okay we’ve got another high-voltage electrical harness here on this end these two electrical connectors connect to our high Power Distribution module on these two empty electrical connectors so let me plug those in and then the other end of this harness goes around back this upper cable right here feeds power to our accessory power module to convert the high voltage DC to low voltage DC so that’s our DC to DC converter this lower connection here is the DC feed out of our onboard charging module so after it’s already converted from AC to DC and stepped-up in voltage then it goes up to the distribution module and then fed back to the battery on this small electrical connector right here and then this last connector is the one that connects to our air conditioning control module up in front of the drive unit so we’ve got a number of electrical connectors here all of these are DC except for these three right here with your three-phase AC now the only harness left is our plug in charge connector harness so let’s take a look at those options next okay the plug in charger that came on our bolt Evie the charge connector looks like this one and notice it does not have the orange door and the two additional DC high-voltage electrical connections there but if we look at this other one that I bought you can see that it does have the little door right here and opens up and you’ve got the two high voltage electrical connectors right there those two high voltage terminals connect to this great big wire harness right here and they come up under the hood and connects right here to the front of our high power distribution module just like that so the when when we plug in the CCS combo charger which is the J 1772 on the top and the two pin DC down below it will already have a DC high voltage DC applied to these wires where it then goes to our distribution module and goes directly through to the back and right back down to the battery itself for a quick charge so when you charge using the high voltage DC fast charge it does not use the onboard charging module to charge the battery now it goes through this distribution block here as I mentioned it also in that distribution block powers up some other systems on the vehicle like the air conditioning compressor module if needed to cool the battery while it is charging and a few other systems for monitoring and so on the one thing it does not power up to my surprise if necessary in cold cold weather is the battery heater so maybe there’s some problems with fast charging a really cold battery and you just simply plug in your your fast charger I’ve heard from people that have the ball TV with the fast charger you plug it into the fast charge when that’s cold then it won’t charge you have to plug in the AC the slow charge the J 1770 to charge complaint charge connector and it actually tells you that in the owner’s manual it says below a certain temperature the fast charge isn’t going to work by the way this fast charge connector here has an additional solenoid and a lock in the connector here that will lock the the CCS combo connector charge connector in place while it’s charging DC high voltage and it won’t let you unplug it until it’s verified that everything that all the voltage has been removed from these terminals and so there’s a to convert to a fast charge both evie you need more than just this harness connector here and the the the distribution module there is a low voltage wire harness that is totally different let me bring that in okay this is the low voltage under hood wire harness and in the electrical connector that goes to this module right here the the high-powered disconnect module this electrical connector if you look at it right now it only has one two three four five wires in the back of that connector the one for the DC fast charge has every wire in there except one and so this one is missing three on the top and four on the bottom so there’s seven potential wires more that it could have the one with the DC fast charge has six more wires in it and I’m sure that has to do with monitoring the voltage so that we can unlock the charge connector there when when it’s done charging and I’ve looked at the wire harnesses this goes all the way in to the hybrid powertrain control module number two under the passenger seat and so there might even be a different in eternal wire harness which makes me wonder if this can even be done without changing all kinds of parts and whether or not the programming is is even able to be done you know just because you buy all the parts doesn’t mean that the modules will configure themselves to be fast charge I’m going to keep playing with it and see but from what I’ve heard it does not work when you do that but it could be that maybe whoever’s I was communicating with about that conversion didn’t realize that there was this wire harness difference as well so let’s just do a quick review and then we’ll be done we’ve got the drive unit of the bolt evie right here I’ll have a separate video on disassembly and reassembly of it that drive unit is controlled by the power inverter module that’s underneath the hood the power inverter module receives its power from the battery through this high power distribution module right above it that you can see under the hood over here we have our DC to DC converter where we have our ground cable that is going to come in and bolt right there we have our power cable that goes to our 12-volt battery and a ground cable for the 12-volt battery as well so that’s our accessory power module right underneath that we have the on-board charging module for when you plug in the high-voltage charger to the side of your car we also have the either the quick charge plug in connector receptacle or the non quick charge version like the one our car came with as a high voltage component we’ve got the air conditioning compressor module the bolts to the front of the drive unit and then in the back we have the heater module for heating the coolant going into the battery and then the one module I did not bring over from the car is the heater for the coolant that goes into the heater core to heat the passenger compartment on cold days so these are all of the high voltage components that are there involved with the Chevrolet bolt evie with the exception of the high voltage battery and if you look at the high voltage battery here I have a separate video on complete disassembly and reassembly of this battery but we’ve got the two orange electrical connectors on the front the great big one is for DC fast charge and feeding the inverter the small one is for the plug-in charger the little black ones are for low voltage connections and then of course it’s a liquid-cooled battery so we have the two coolant pipe one for the inlet and one for the outlet all right so this has just been a basic review of the bolt evie high voltage electrical systems I plan on having a video on the disassembly of every one of these components here coming up I still need to finish my history of automatic transmission fluid videos before I dive too far into this but the classes I’m teaching here at Weber State University made me interrupt my automatic transmission fluid history video shooting and get to this because we are towards the end of the semester and this is what I wanted to show my students before they left for Christmas break so that is it thank you for watching [Music] you [Music] [Applause] [Music] [Music]


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