Electrical System Form FSAE-E2013 University of California, San Diego Triton Racing Car: E215

Transcription

1 Electrical System Form FSAE-E2013 University of California, San Diego Triton Racing Car: E215 Contact: Prithvi Sundar (408)

2 University Name, Car Number Table of Contents Table of Contents Table of Contents... ii I List of Figures... vi II List of Tables... viii III List of Abbreviations... ix 1 System Overview Electrical Systems Shutdown Circuit Description/concept Wiring / additional circuitry Position in car IMD Description (type, operation parameters) Wiring/cables/connectors/ Position in car Inertia Switch Description (type, operation parameters) Wiring/cables/connectors/ Position in car Brake Plausibility Device Description/additional circuitry Wiring Position in car/mechanical fastening/mechanical connection Wiring/cables/connectors/ Position in car Reset / Latching for IMD and BMS Description/circuitry Wiring/cables/connectors Position in car Shutdown System Interlocks Description/circuitry Formula SAE Electric ii

3 Table of Contents Wiring/cables/connectors Position in car Tractive system active light Description/circuitry Wiring/cables/connectors Position in car Measurement points Description Wiring, connectors, cables Position in car Pre-Charge circuitry Description Wiring, cables, current calculations, connectors Position in car Discharge circuitry Description Wiring, cables, current calculations, connectors Position in car HV Disconnect (HVD) Description Wiring, cables, current calculations, connectors Position in car Ready-To-Drive-Sound (RTDS) Description Wiring, cables, current calculations, connectors Position in car Accumulator Accumulator pack Overview/description/parameters Cell description Cell configuration Cell temperature monitoring Formula SAE Electric 3

4 Table of Contents Accumulator insulation relays Fusing Battery management system Accumulator indicator Wiring, cables, current calculations, connectors Charging Mechanical Configuration/materials Position in car Energy meter mounting Description Wiring, cables, current calculations, connectors Position in car Motor controller Motor controller Description, type, operation parameters Wiring, cables, current calculations, connectors Position in car Motors Motor Description, type, operating parameters Wiring, cables, current calculations, connectors Position in car Torque encoder Description/additional circuitry Wiring Position in car/mechanical fastening/mechanical connection Additional LV-parts interfering with the tractive system LV part Description Wiring, cables, Position in car Overall Grounding Concept Formula SAE Electric 4

5 Table of Contents 9.1 Description of the Grounding Concept Grounding Measurements Firewall(s) Firewall Description/materials Position in car Appendix Formula SAE Electric 5

6 I List of Figures I List of Figures Figure 1 System Block Diagram...2 Figure 2 Car Isometric View...3 Figure 3 Car Back View...6 Figure 4 ESS View...6 Figure 5 IMD Schematic...7 Figure 6 Rear Electrical Components...8 Figure 7 Dashboard...9 Figure 8 Brake Plausibility Device...10 Figure 9 Pedal Assembly Isometric View...11 Figure 10 Shutdown Interlocks...12 Figure 11 HVD parts...17 Figure 12 HVD Removal...17 Figure 13 RTDS circuit...18 Figure 14 Accumulator Schematic...21 Figure 15 Temperature Multiplexer Arrangement...22 Figure 16 Battery Pack Front Isometric View...26 Figure 17 Battery Pack Back Isometric View...26 Figure 18 Battery Pack Top View...27 Figure 19 Motor Torque/Horsepower vs RPM...32 Figure 20 Motor Speed vs Power...32 Figure 21 Motor Schematic...33 Figure 22 Firewall Section 1 Isometric View Formula SAE Electric vi

7 I List of Figures Figure 23: Firewall Section 1 Secondary View...39 Figure 24: Firewall Section 2 Isometric View Formula SAE Electric vii

8 II List of Tables II List of Tables Table 1.1 General parameters... 3 Table 2.1 List of switches in the shutdown circuit... 5 Table 2.2 Wiring Shutdown circuit... 5 Table 2.3 Parameters of the IMD... 8 Table 2.4 Parameters of the Inertia Switch... 9 Table 7.1 Torque encoder data Table 2.6 Parameters of the TSAL Table 2.7 General data of the pre-charge resistor Table 2.8 General data of the pre-charge relay Table 2.9 General data of the discharge circuit Table 3.1 Main accumulator parameters Table 3.2 Main cell specification Table 3.3 Basic AIR data Table 3.4 Basic fuse data Table 3.5 Fused Components Rating Data Table 3.6 BMS Lithiumate Lite Data Table 3.7 Belden, 0.81 mm^ Table 3.8 Radicle, 1/0 AWG Table 3.9 General charger data Table 5.1 General motor controller data Table 6.1 General motor data Table 7.1 Torque encoder data Formula SAE Electric viii

9 III List of Abbreviations III List of Abbreviations BMS: Battery Management System IMD: Insulation Monitoring Device ESS: Emergency Shutdown Switch LSD: Left Shutdown (Left ESS) RSD: Right Shutdown (Right ESS) FSD: Front Shutdown (Front ESS) KSI: Key Switch Ignition HVD: High Voltage Disconnect TSAL: Tractive System Active Light TSMS: Tractive System Master Switch CSMS: Control System Master Switch GLVMS: Ground Low Voltage Master Switch (same as CSMS) AIRs: Accumulator Isolation Relays ECU: Electrical Control Unit TSMP: Tractive System Measuring Point GLVMP: Ground Low Voltage Measuring Point OT: Over Travel PCB: Printed Circuit Board 2013 Formula SAE Electric ix

10 1 System Overview 1 System Overview High energy density Lithium Cobalt pouch cells designed into an in-house fabricated battery pack. The light cells distributed into 4 banks drive a powerful motor with high torque output. Black, Red, Blue = 18 AWG Orange = 1/0 AWG *shared nodes shown with black dot *only one microcontroller, split up to make wiring visual easier to follow Figure 1: System Block Diagram Maximum Tractive-system voltage: Nominal Tractive-system voltage: Control-system voltage: Accumulator configuration: 120VDC 118VDC 12VDC, 24VDC 9p32s 2013 Formula SAE Electric 2

11 1 System Overview Total Accumulator capacity: Motor type: 45Ah 3 phase AC induction motor Number of motors: 1 Maximum combined motor power in kw 55kW Table 1.1 General parameters Figure 2: Car Isometric View 2013 Formula SAE Electric 3

12 2 Electrical Systems 2.1 Shutdown Circuit 2 Electrical Systems Description/concept There are various components in the car that make up the shutdown circuit. The main purpose of this circuit is to open the ground low voltage system of the car in the event of a potentially unsafe electrical event, which in turn will open the AIRs rendering the car un-drivable. The following is the procedure to power on the ground low voltage system (control circuit of the car): 1. Close all safety shutdown buttons (front, right, and left) 2. Close brake over travel switch 3. Make sure IMD is installed and turned ON 4. Make sure BMS is installed and turned ON 5. Close inertia switch 6. Check pedal position, so brake plausibility device is not tripped 7. Make sure High Voltage Disconnect is installed 8. Make sure ECU is installed 9. Turn on CSMS 10. Turn on TSMS 11. Turn on KSI Part Main Switch (for control and tractive-system; CSMS, TSMS) Brake over travel switch (BOTS) Shutdown buttons (SDB): Front, Right, Left ESS Function Normally open Normally closed Normally closed 2013 Formula SAE Electric 4

13 2 Electrical Systems Insulation Monitoring Device (IMD) Battery Management System (BMS) Inertia Switch Interlocks Brake Plausibility Device High Voltage Disconnect (HVD) ECU shutdown Motor Controller shutdown (Main Relay) / Key Switch Ignition Normally open Normally open Normally closed Normally Open, Closed when circuits (HV and LV) are connected Normally Open Normally Closed Normally Open Normally Open Table 2.1 List of switches in the shutdown circuit Wiring / additional circuitry Total Number of AIRs: 5 Current per AIR: Additional parts consumption within the shutdown circuit: Total current: Cross sectional area of the wiring used: 3 Amps initial, 0.1 Amps Holding Current 2A 15A 0.81 mm² Table 2.2 Wiring Shutdown circuit Position in car See below and Figure 2 for more information Formula SAE Electric 5

14 2 Electrical Systems Figure 3: Car Back View Figure 4: ESS view 2013 Formula SAE Electric 6

15 2 Electrical Systems 2.2 IMD Description (type, operation parameters) The Insulation Monitoring Device used in our car is the A-Isometer IR The IMD light is hooked up to a battery through a transistor that routes current to the light whenever there is an IMD fault. Figure 5: IMD Schematic Supply voltage range: Supply voltage: Environmental temperature range: Selftest interval: VDC 12VDC C Always at startup, then every 5 minutes 2013 Formula SAE Electric 7

16 2 Electrical Systems High voltage range: Set response value: Max. operation current: Approximate time to shut down at 50% of the response value: DC V 60kΩ (500Ω/Volt) 150mA 20s Table 2.3 Parameters of the IMD Wiring/cables/connectors/ All of the wiring that is associated with the IMD is routed into the ECU box where the IMD is housed. The wiring up to the box containing the IMD wiring will be routed through a braided cable cover. High voltage side and low voltage side leading up to the IMD are mated with Molex Minifit Jr. connectors using AWG 18 wires Position in car Figure 6: Rear Electrical Components 2013 Formula SAE Electric 8

17 2 Electrical Systems 2.3 Inertia Switch Description (type, operation parameters) The inertia switch used in our car is a mechanically triggered and resettable switch. It features a magnet restrained mass inertia system. It is responsive to a 360 degree impact. It does not use any form electricity for power. Inertia Switch type: Sensata Supply voltage range: N/A Supply voltage: N/A Environmental temperature range: C Max. operation current: 10 Amps Trigger characteristics: 15 ms for 10g, 45 ms for 5g Table 2.4 Parameters of the Inertia Switch Wiring/cables/connectors/ The inertia sensor is positioned in the dashboard of our car. There are other switches on the dash that are part of GLVS. This allows there to be one inlet cable to the dash and one outlet cable from the dash. 18 AWG wires terminated with Krimptite Quick Disconnect Terminal will be used to incorporate the inertia switch in the GLVS Position in car Figure 7: Dashboard 2013 Formula SAE Electric 9

18 2 Electrical Systems 2.4 Brake Plausibility Device Description/additional circuitry The brake plausibility device will be part of a PCB. It will take in the raw throttle signal and brake signal. Through a comparator the device will determine if there is an implausibility. If there is an implausibility, the throttle signal will then be cut from being sent to the motor controller and the arduino will open the GLVS system which in turn opens the AIRs. Brake sensor used: Torque encoder used: Supply voltages: Maximum supply currents: Bourns 3046 Linear Motion Potentiometer Bourns 3046 Linear Motion Potentiometer 5V 20mA Operating temperature: -55 C to +125 C Output used to control AIRs: Open a relay Table 2.5 Torque encoder data Wiring Figure 8: Brake Plausibility Device 2013 Formula SAE Electric 10

19 2 Electrical Systems Position in car/mechanical fastening/mechanical connection The potentiometers will be incorporated into the pedal assembly. Separate fixtures for each of the components will be fabricated that will allow us to bolt the sensors to the pedal assembly. Similarly, the PCB that acts as the Brake Plausibility Device will be housed in a small shock resistant box which will be affixed to the Pedal assembly through mounting screws Wiring/cables/connectors/ All of the wiring associated with this device and the throttle inputs will be routed through the Brake Plausibility Device Box. This will allow us to run only one braided cable from the front of the car to the ECU box where all the processing will occur. A Molex Minifit Jr. Connectors will be incorporated into the design of the board therefore all of the sensor wire will be able to connect to the board and a single output connector can be used Position in car Figure 9: Pedal Assembly Isometric View 2013 Formula SAE Electric 11

20 2 Electrical Systems 2.5 Reset / Latching for IMD and BMS Description/circuitry Both the IMD and BMS have their own separate battery for power. A simple reset switch will be used in series with their supply voltages to reset each of the devices. After proper rectification of the error this button can be pressed to allow the driver to drive the car. See Figure 1 for schematic Wiring/cables/connectors The reset switches for both devices will be located on the dash, as described for the inertia switch (see 2.3.2). Krimptite Quick Disconnect Terminal terminating AWG 18 wires will be used Position in car See Figure 7 in section Shutdown System Interlocks Description/circuitry There are three other relays and contactors which also are able to open the GLVS and in turn the AIRs in the event of an unsafe event. These components are: 1. BMS relay (acts through the ECU relay) 2. IMD relay 3. ECU relay Figure 10: Shutdown Interlocks 2013 Formula SAE Electric 12

21 2 Electrical Systems Wiring/cables/connectors These relays will be incorporated onto a PCB, which will have Krimptite Quick Disconnect Terminals terminating AWG 18 wires Position in car These relays will be housed in the ECU box. (See Figure 6 in section 2.2.3) 2.7 Tractive system active light Description/circuitry The tractive system active light blinks at a certain frequency to show that the main contactors have been closed and the GLVS and Tractive System are linked. A light is wired in series with the AIRS so it will turn on only when all the AIRs have closed. Supply voltage: Max. operational current: Lamp type Power consumption: Brightness Frequency: Size (length x height x width): 12VDC 500mA Halogen 6 W 450 Lumen 1.5Hz 101.6mm x 101.6mm x 101.6mm Table 2.6 Parameters of the TSAL Wiring/cables/connectors The TSAL and the RTDS will be housed within the same case. This will allow us to run the supply and signal lines to both the TSAL and RTDS in a single braided cable. A Molex Minifit Jr. with 18 AWG wire will be used and plugged into the side of the TSAL/RTDS box. The TSAL can be seen in Figure 1, incorporated into the safety shutdown circuit Position in car The TSAL will be affixed on the main hoop, while the TSAL circuit will contained in the ECU box since it requires both HV and 24V. See Figure 4 in section Formula SAE Electric 13

22 2 Electrical Systems 2.8 Measurement points Description Our car uses 2 red 4 mm banana jacks marked with polarity for the HV as the TSMPs. 1 yellow 4 mm banana jack and 1 black 4 mm banana jack will be marked with polarity for the GLVMP Wiring, connectors, cables The TSMPs will be located on the exterior of the ECU box. A simple acrylic cover that is hinged will be installed over the TSMPs and GLVMPs to avoid possible interaction with the environment. A pair of AWG18 wires are used to connect the banana jacks to the HV circuit, at the B+ and B- position of the accumulator pack. A seperate pair of AWG 18 wires are use used to connect the banana jacks to the GLVS Position in car See Figure 6 in section Pre-Charge circuitry Description The Pre-Charge circuitry is internally built into the Curtis controller that our car uses. By default the pre-charge circuit is enabled, this can be changed through Vehicle Control Language (VCL). Due to the proprietary nature of the product we were unable to gain access to technical specifications of the pre-charge circuitry Wiring, cables, current calculations, connectors With the pre-charge function enabled, power will be supplied to the capacitor bank until the voltage is within 3 volts of KSI, or pre-charge second has expired, or the pre-charge resistor energy range has been exceeded. The current state of pre-charge is shown by the pre-charge variable (Precharge_State), which has the following values: 0 Pre-charge has not yet been done. 1 Pre-charge is in progress. 2 Pre-charge has passed. 3 Pre-charge has been aborted by the Disable_Precharge() function. 4 Pre-charge has exceeded the pre-charge resistor energy 2013 Formula SAE Electric 14

23 2 Electrical Systems Resistor Type: Resistance: Continuous power rating: Overload power rating: Voltage rating: Cross-sectional area of the wire used: Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed N/A Table 2.7 General data of the pre-charge resistor Relay Type: Contact arrangment: Continuous DC current: Voltage rating Cross-sectional area of the wire used: Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed Table 2.8 General data of the pre-charge relay Position in car The pre-charge circuitry is contained within the Curtis 1238R-7601 motor controller. See Figure 6 in section Discharge circuitry Description The Curtis 1238R-7601 controller takes in the battery DC inputs at the B+ and B- terminals and transforms it into a 3 phase AC signal discharged to the motor Wiring, cables, current calculations, connectors The discharge circuitry is internally built into the Curtis 1238R-7601 controller that our car uses. By default the discharge circuit is enabled. Due to the proprietary nature of the product we were unable to gain access to technical specs of the pre-charge circuitry 2013 Formula SAE Electric 15

24 2 Electrical Systems Resistor Type: Resistance: Continuous power rating: Overload power rating: Voltage rating: Maximum expected current: Average current: Cross-sectional area of the wire used: Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed Undisclosed Table 2.9 General data of the discharge circuit Position in car The pre-charge circuitry is contained within the Curtis 1238R-7601 motor controller. See Figure 6 in section HV Disconnect (HVD) Description Our car will feature the EV EZ Safe Disconnect along with the Anderson Power Products SB 2-pole electrical connectors, models SB175. The lever on top of the mechanism makes disconnection and reconnection of the circuit easy and direct, while a pull-cable attachment allows for disconnection from a distance. The lever must be pusshed to disengage connection Wiring, cables, current calculations, connectors The HVD will be placed on the exterior of the ECU box, which is located next to the Master Switches and TSMPs Position in car For positioning see Figure 6 in section Formula SAE Electric 16

25 2 Electrical Systems Figure 11: HVD parts Figure 12: HVD Removal 2.12 Ready-To-Drive-Sound (RTDS) Description The RTDS in our car is a simple piezoelectric buzzer operated by the ECU. As soon as the TSMS is closed a secondary transistor allows current to flow to the ECU which in turn actuates the RTDS Formula SAE Electric 17

26 2 Electrical Systems Figure 13: RTDS circuit Wiring, cables, current calculations, connectors As mentioned in section for the TSAL, the RTDS and TSAL will be housed in the same case. As mentioned in there will be a single Molex Minifit Jr connector to interface with the TSAL and the RTDS Position in car See Figure Formula SAE Electric 18

27 3 Accumulator 3.1 Accumulator pack 1 3 Accumulator Overview/description/parameters The accumulator pack is made up of 288 low profile pouch cells. They are configured in such a way that if one cell fails the entire circuit does not shut off unless the BMS does so. The cells are divided into 4 subsections and contained in an acrylic container. Maximum Voltage: Nominal Voltage: Minimum Voltage: Maximum output current: Maximum nominal current: Maximum charging current: 134.4VDC 118VDC 0VDC 900A for 10s 650A 90A Total numbers of cells: 288 Cell configuration: Total Capacity: 9p32s kwh or MJ Number of cell stacks < 120VDC 4 Table 3.1 Main accumulator parameters Cell description The cells in our accumulator are a low profile Lithium Cobalt Cell capable of high discharge and high capacity. Cell Manufacturer and Type Cell nominal capacity: Turnigy Lipoly 5 Ah 2013 Formula SAE Electric 19

28 3 Accumulator Maximum Voltage: 4.2 V Nominal Voltage: 3.7V Minimum Voltage: 2.8V Maximum output current: Maximum nominal output current: Maximum charging current: 20C for 10s 15C 2C Maximum Cell Temperature (discharging) 65 C Maximum Cell Temperature (charging) 55 C Cell chemistry: LiCo Table 3.2 Main cell specification Cell configuration Each of the 4 containers of the battery pack will contain 72 cells. Each battery will contain 9 cells in parallel. 8 of these batteries will then be hooked up in series. The AIRS will serve as the junction between each of the isolated containers. Each cell will have an 80 Amp fusible link wired to its negative terminal Formula SAE Electric 20

29 3 Accumulator Figure 14: Accumulator Schematic Cell temperature monitoring 22 of the cells in each of the containers will be monitored using analog temperature sensors. The temp sensors will be affixed to the cell center with thermal paste. The signals from each of the temperature sensors will be fed into a PCB that contains a multiplexing array that will allow us to read the temperature of each cell being monitored. Figure 15: Temperature Multiplexer Arrangement 2013 Formula SAE Electric 21

30 3 Accumulator Accumulator insulation relays Our car features 5 Kilovac EV-200AAANA contactors. They are single-pole, normally-open contacts, hermetically sealed, with built-in arc suppression diodes and pre-charge circuits. The case is made from a high temperature plastic. Relay Type: Contact arragment: Continous DC current rating: Overload DC current rating: Maximum operation voltage: Nominal coil voltage: Normal Load switching: Maximum Load switching EV200 Series Contactor (CZONKA Relay, Type III) 1 Form X (SPST-NO-DM) 500A 2000A for 12 msec 900VDC 12VDC Make and break up to 650A 10 times at 2500A Table 3.3 Basic AIR data Fusing Fuse type: Continous current rating: Maximum operating voltage Type of fuse: I2t rating: Interrupt Current (maximum current at which the fuse can interrupt the current) American Round Fuses A30QS 500A 300VDC Fast Acting 130A2s at 300VDC 4500A Table 3.4 Basic fuse data 2013 Formula SAE Electric 22

31 3 Accumulator Component Curtis Motor Controller Wiring: 1/0 AWG Current Rating 650 Amps Duty Cycle 20% Duty Cycle) Table 3.5 Fused Components Rating data Battery management system Each battery is defined as 9 cells in parallel. These batteries will be monitored by our digital BMS, the Lithiumate Lite which is manufactured by e-lithion. It uses distributed cell boards to monitor cell voltages and temperatures. -Fusible link wire will be integrated into connections from BMS Slave boards. -BMS reacts to an upper voltage of 4.2 Volts and Lower Voltage of 3.7 Volts per battery. BMS reacts by actively shutting down the GLVS which opens the AIRs and cuts the load on the batteries. -When more than 65 Degrees Celsius detected, the BMS will open the GLVS circuit using the interlock shutdown system. Supply Voltage Nominal current 12VDC 50 ma Number of monitored banks 8 Bidirectional Load Current Bidirectional Charger Current Up to 900 A Up to 30 A Table 3.6 BMS Lithiumate Lite data -9 cells will be sensed by each set of BMS slaves (consists of 2 end boards and a middle board). -Communication ports between boards are protected through the connectors that are used to secure them. -The GLVS will be opened through a relay which will in turn open the AIRs if an error is detected 2013 Formula SAE Electric 23

32 3 Accumulator Accumulator indicator Each container of the accumulator will only contain a max of 30 VDC when the AIRs are not closed. Therefore, once the AIRs are closed, the accumulator indicator will turn on. See Figure Wiring, cables, current calculations, connectors The maximum voltage is 120VDC and the maximum current is 900A. The motor controller will take a max of 650A and a continuous rating of 155A from the batteries. 1/0 AWG wires will satisfy the amperage range with minimal energy loss. The fuse symbols represent fusible links and they will be connected to the positive terminal of each battery cell. The orange colored lines are 1/0 wires and black and red lines are 18 AWG wires (see wiring diagram). Wire type Continuous current rating: Cross-sectional area Maximum operating voltage: Temperature rating: Wire connects the following components: Belden, 18 AWG No continuous rating, 20A max 0.81 mm² 600VDC -40 C To +105 C AIRs, BMS Table 3.7 Belden, 0.81mm² Wire type: RADAFLEX 1/0 AWG, 50mm² Current rating: Duty Cycle 20% Duty Cycle) Maximum operating voltage: 600V Temperature rating: -30 C to 90 C Wire connects the following componets: Accumulator Containers Table 3.8 Radicle, 1/0 AWG 2013 Formula SAE Electric 24

33 3 Accumulator Charging The wires from the battery pack to the B+ and B- terminals to the motor controller will be disconnected. The terminating ring type connectors will be attached to the alligator clips of the charger. BMS and IMD will be powered through their own auxiliary batteries, to ensure safe charging. The charger will be hooked up to the BMS as well during the charging process to avoid over and under charging of cells. Active monitoring of BMS can be done through a computer connection if needed. Charger Type: Maximum charging power: Maximum charging voltage: Maximum charging current: Interface with accumulator Input voltage: HWC4 6 Stage 1.2kW 120V 10A Alligator clips to ring type connectors 220 VAC Input current: 11.7A Table 3.9 General charger data Mechanical Configuration/materials Note that in the following renderings the dividing walls have been removed to better show the internal configuration of the cells Formula SAE Electric 25

34 3 Accumulator Figure 16: Battery Pack Front Isometric View Figure 17: Battery Pack Back Isometric View 2013 Formula SAE Electric 26

35 3 Accumulator Figure 18: Battery Pack Top View Position in car See Figure Formula SAE Electric 27

36 4 Energy meter mounting 4 Energy meter mounting 4.1 Description The ECU box will have leads of the B+ and B- terminals available for the Energy Meter to mount to. The top of the ECU box will be made of a see-through plastic allowing the meter to be visible. 4.2 Wiring, cables, current calculations, connectors Energy will pass directly through the energy meter from the battery pack to the motor controller and vice versa. Inside the ECU box the terminals of the 2/0 AWG wire will have a mating connector allowing it to interface with the Energy Meter. 4.3 Position in car The Energy Meter will be mounted inside of the ECU box. See Figure 6 in Section Formula SAE Electric 28

37 5 Motor Controller 5 Motor controller 5.1 Motor controller Description, type, operation parameters The Curtis 1238R-7601 motor controller was specifically design for the HPEVS AC35 motor (see 5.2). Therefore the motor controller ratings are the same as the motor ratings. Motor controller type: Curtis 1238R-7601 Maximum continous power: Maximum peak power: Maximum Input voltage: Output voltage: Maximum continuous output current: Maximum peak current: Control method: Cooling method: Auxiliary supply voltage: 14.8kW 62.4kW for 2 minutes 96VDC 67VAC 155A 650A PWM Air N/A Table 5.1 General motor controller data Wiring, cables, current calculations, connectors The Curtis 1238R-7601 is the limiting factor in how much current the motor receives. In such a case, the continuous current rating for the motor controller is 155 Amps and the RADAFLEX 1/0 AWG cable is able to take Duty Cycle and 20% Duty Cycle. Wire type: RADAFLEX 1/0 AWG, 50mm² Current rating: Duty Cycle 20% Duty Cycle) 2013 Formula SAE Electric 29

38 5 Motor Controller Maximum operating voltage: 600V Temperature rating: -30 C to 90 C Position in car See Figure 6 in section Formula SAE Electric 30

39 6 Motors 6 Motors 6.1 Motor Description, type, operating parameters We are using the High Performance Electric Vehicles (HPEVS) AC35 (formerly AC31) AC induction motor. See table and graphs below for more information. Motor Manufacturer and Type: Motor principle Maximum continuous power: Peak power: Input voltage: Nominal current: Peak current: Maximum torque: Nominal torque: Cooling method: High Performance Electric Vehicles (HPEVS) AC35 (formerly AC31) Brushless AC Induction 14.8kW 62.4kW for 2 minutes 96VAC 155A 650A 162Nm 100Nm Air Table 6.1 General motor data HPEVS does not provide graphs with nominal lines. Please see for more information Formula SAE Electric 31

40 6 Motors Figure 19: Motor Torque/Horsepower vs. RPM Figure 20: Motor Speed vs. Power 2013 Formula SAE Electric 32

41 6 Motors Wiring, cables, current calculations, connectors Figure 21: Motor Schematic Position in car See Figure 6 in section Formula SAE Electric 33

42 7 Torque Encoder 7 Torque encoder 7.1 Description/additional circuitry Describe the type of the torque encoder(s) used, provide tables with main operation parameters, and describe additional circuitry used to check or manipulate the signal going to the motor controller. Describe how the system reacts if an implausibility or error (e.g. short circuit or open circuit or equivalent) is detected. Torque encoder manufacturer and type: Torque encoder principle: Supply voltage: Maximum supply current: Bourns 3046 Linear Motion Potentiometer Potentiometer 5V 20mA Operating temperature: -55 C to +125 C Used output: V Table 7.1 Torque encoder data 7.2 Wiring The raw encoder signal will be routed through the PCB which contains the Brake Plausibility Device. This will check for implausibility of the torque encoders as well as with respect to the brake signal. If there is implausibility, the throttle signal will then be cut from being sent to the motor controller and the arguing will open the GLVS system which in turn opens the AIRs. 7.3 Position in car/mechanical fastening/mechanical connection The potentiometer will be incorporated into the pedal assembly. Separate fixtures for each of the components will be fabricated that will allow us to bolt the sensors to the pedal assembly. Similarly, the PCB that acts as the Brake plausibility device will be housed in a small shock resistant box which will be affixed to the Pedal assembly through mounting screws Wiring/cables/connectors/ All of the wiring associated with this device and the throttle inputs will be routed through the Brake Plausibility Device Box. This will allow us to run only one braided cable from the front of the car to the ECU box where all the processing will occur. Molex Minifit Jr. connectors will be incorporated into the design of the board therefore all of the sensor wire will be able to connect to the board and a single output connector can be used Formula SAE Electric 34

43 7 Torque Encoder Position in car See Figure 8 in section Formula SAE Electric 35

44 8 Additional LV-parts interfering with the tractive system 8 Additional LV-parts interfering with the tractive system 8.1 LV part 1 ELCON TDC-10812EGC Description The DC to DC converter is used to step down 96VDC to 12VDC to power the Tractive System Active Light (TSAL). This is still a prototype and will probably not be used in the final stage of our car Wiring, cables, This is still a prototype and will probably not be used in the final stage of our car Position in car This converter will be contained in the ECU box of the car, shown in Figure Formula SAE Electric 36

45 9 Overall Grounding Concept 9 Overall Grounding Concept 9.1 Description of the Grounding Concept We are using LIQUID-TUFF UL Type A Orange, Type LFNC-A Liquid-tight Flexible Non-Metallic Conduit to achieve isolation between the high voltage wiring to the chassis. The 1/0 wires will be ran through the conduit to prevent high voltage grounding to the chassis. The GLV wires are going to be isolated from the chassis by heat shrinking the GLV wiring harness. These methods paired with the IMD will ensure the wires will not short to the chassis. Refer to datasheet The chassis of our car as well as the shear panels are constructed from AISI Chromoly 4130N Steel. The GLVS is grounded to the chassis through ring type connectors screwed into grounding weld-nuts around various points in the car. The chassis will be powder coated but the coating will be removed in areas where the grounding nuts will be attached. 9.2 Grounding Measurements The grounding measurements will be achieved by applying a Multimeter set to measure resistance between the component that should be grounded and its associated grounding nut. This resistance will be measured then the components resistance will be measured again in reference to a common ground that is placed at the front of the car near the front impact structure Formula SAE Electric 37

46 10 Firewall 10 Firewall(s) 10.1 Firewall Description/materials The firewall will be placed in close proximity with the seat and the battery pack. It will completely separate the battery and tractive system components from the driver. The first section will be made into a modular shape that will slide over the battery pack. The second section will conform to the back of the seat and connect be attached to the headrest mount. The firewall will be made from ITW Formex. This is a moldable and easy to use material that is fire retardant and electrically insulating. The Formex firewall will directly contact the lower members of the side impact structure to achieve grounding Position in car Figure 22: Firewall section 1Isometric View 2013 Formula SAE Electric 38

47 10 Firewall Figure 23: Firewall Section 1 Secondary View Figure 24: Firewall Section 2 isometric view 2013 Formula SAE Electric 39

48 11 Appendix 11 Appendix A-Isometer iso-f1 IR Sensata Inertia Switch Krimptite Quick Disconnect Terminal Banana Jacks 4mm EV EZ Safe Disconnect Piezo Buzzer Turnigy 5000mAh Lipoly Battery Kilovac EV-200AAANA Ferraz 500A Fuse Elithion Lithiumate Lite Belden 18 AWG Wire HWC4 Charger Curtis 1238R-7601 Motor Controller RADAFLEX 2/0 AWG Cable Bourns 3046 Linear Motion Potentiometer ELCON TDC-10812EGC LIQUID-TUFF Flexible Non-Metallic Conduit Electrical Insulating Material Formex 2013 Formula SAE Electric 40