Enhanced Efficient Thermal Control System (EETCS) Group 18 Lucas Chokanis Daniel Ramirez Lloyd Harrison Philip Teten
Feb 25, 2016
Enhanced Efficient Thermal Control System
(EETCS)Group 18
Lucas ChokanisDaniel RamirezLloyd Harrison
Philip Teten
A Proposal from Researchers to Implement Their Algorithms
Design a Power Efficient Thermostat to Control a Vehicle’s Heating, Ventilation, and Air Conditioning (HVAC) Systems
Create a Control System That will Significantly Extend the Life-Cycle of a Vehicle’s Battery
Provide a Control System that is Feasible to adapt for Future Additions
Motivation
Ability to Detect Input:◦ Temperature of the Vehicles Interior◦ Temperature of the Evaporator◦ Extra Temperature Sensor for Researchers Use
Control Output:◦ Speed of the blower motor (High, Med, & Low)◦ Speed command of the PMSM motor.◦ Condenser Fan◦ Clutch Control?
Implement a User Interface◦ LCD Screen and LED’s for Feedback◦ Push Buttons for User Control
Objectives
Electrically Noisy Environment:◦ Use of Parts that Meet Automotive Requirements
15 ft Transmission Lines:◦ PMSM Motor Control◦ Remote Temperature Sensors
Highly Intuitive Programming:◦ Giving Researchers Ease of Understanding
Challenges
Voltage Recieved: ◦ 12 VDC to 15 VDC
Output to Motors: ◦ 12 VDC Three Speed with Separate Hi, Med, Low input◦ 12 VDC On/OFF 12VDC motor.◦ Linear 0-3.3V “ramp” speed command
Relays:◦ Coil Voltage of 12 VDC
Microcontroller◦ MSP430◦ C2000
Specifications and Requirements
The Proposed System
Microcontroller
Parametrics MSP430F2274-Q1
TMS320F28030
LM4F110B2QR
Architecture 16-bit 32-bit 32-bitFlash (KB) 32 32 32Frequency
(MHZ)16 60 80
RAM (KB) 1 12 12GPIO 32 44 43I2C 1 1 4
UART 1 1 8SPI/SSI 1 2 4
ADC 10-Bit/12 channels 12-bit/16 channels 12-bit/12 channelsRating Automotive Standard Standard
Microcontroller
The chosen microcontroller is the MSP430F2274-Q1 for the following reasons: Ultra-Low power Code Composer Studio IDE Qualified for Automotive applications Sponsor provided the MSP430 Target board
and USB programmer Temperature sensor
Microcontroller
Temperature Sensors
Ambient temperature Sensor:◦ Housed on main thermostat circuit board.◦ Provides feedback to the user via LCD screen
Evaporator temperature Sensor:◦ Remote sensor location. ◦ 15ft away from main board as required by the customer. Its purpose is
to keep track of the rate at which the evaporator is cooling.◦ Prevents the evaporator from freezing over.◦ Feeds data back to the MCU to be that will be used to improve
efficiency.
Auxiliary Temperature Sensor:◦ Remote sensor location (<15ft away from main board).◦ Feeds data back the MCU to be used to improve efficiency.
Temperature Sensors
Model Manufacturer Accuracy Temp. Range
Current Draw
Output Price $
LM35A Texas Instruments
±0.2ºC -40ºC to 110ºC
60µA Linear Voltage
5.60
LM35CA Texas Instruments
±0.2ºC -40ºC to 110ºC
60µA Linear Voltage
14.61
ADT7420 Analog Devices ±0.2ºC -40ºC to 125ºC
265µA 16-Bit 4.87
ADT7320 Analog Devices ±0.2ºC -40ºC to 125ºC
265µA 16-BitSPI
4.87
TMP100 Texas Instruments
±3ºC -55ºC to 125ºC
45µA 2.15
Temperature Sensors
The chosen temperature sensors were the ADT7320 for the following reasons: Very high accuracy rating on a wide
temperature scale. We can expect reliable temperature
readings in a cold environment such as the evaporator.
User programmable with multiple features Temperature resolution up to 16-bits.
Temperature Sensors
Temperature Sensors
Extending The SPI Bus for Long Distance Communication:◦ For the remote sensors, it is possible that propagation
delay could be significant enough to hinder data transmission.
◦ Once we attempt to conduct SPI communications at distances greater than 15 feet, we will know if propagation delay will require a hardware solution.
◦ If this turns out to be the case, dual differential transceivers will be used to refresh the clock signal protect the data transfer from noise.
◦ If the signal is fed back to the master from the slave, data transmissions between the master and slave will occur at the same delayed clock signal.
Temperature Sensors Communication
Temperature Sensors Communication
User Interface
User Interface
User Interface 4 Digits 1 Decimal Accuracy
LCD Display and Driver Driver Uses Less Pin Outs Good for Intuitive Programming
B3 B2 B1 B0 LCD Display
0 0 0 0 00 0 0 1 10 0 1 0 20 0 1 1 30 1 0 0 40 1 0 1 50 1 1 0 60 1 1 1 71 0 0 0 81 0 0 1 91 0 1 0 A1 0 1 1 b1 1 0 0 C1 1 0 1 d1 1 1 0 E1 1 1 1 F
D1 D2 D3
D4 Function
0 0 0 0 No Change0 0 0 1 Store Data in Latch 4 to be Displayed in
Digit 40 0 1 0 Store Data in Latch 3 to be Displayed in
Digit 30 1 0 0 Store Data in Latch 2 to be Displayed in
Digit 21 0 0 0 Store Data in Latch 1 to be Displayed in
Digit 11 1 1 1 Store Data in All Data Latches, Display All
LCD Display and Driver
User Interface 4 Digits 1 Decimal Accuracy
User Interface View Changing: Scroll Through
User Interface Temperature Set for Nominal Setting
User Interface Setting the Blower Motor State
PMSM Communication
PMSM Communication
PMSM Communication
Analog Out0.165V to 2.13510 Settings
PMSM Communication
PWM Input
PMSM Communication
Lowpass FilterEliminates High Frequency ComponentsMaintains Analog DC Valuew0 = 1/RC = 1kHz
PMSM Communication
Dual Differential DriverTo Drive the 15’ of CableBetter Noise ImmunityDO+1=DI1/2DO-1 = -DI1/2
PMSM Communication
Shielded Twisted PairHigher Noise ImmunityNoise Cancels
PMSM Communication
Dual Differential RecieverR2OUT2 = (RIN2+) – (RIN2-)
PMSM Communication
Analog Out0.165V to 2.13510 Settings
Power and Motor Control
Solid-State Relays (SSRs) Vs. Electromechanical Relays:
Motor Control
Relay Type Pros ConsSolid-state Faster switching
times Increased lifetime (no
moving parts) Bounceless switching No sparking or arcing Silent operation
Higher ON resistance (more power dissipated)
Small OFF resistance (small reverse leakage current)
Fails “short”Electromechanical Lower ON
resistance (ohmic contacts)
Higher OFF resistance (no current flow)
Fails “open”
Noisy Shorter lifetime
(10^5 to 10^7 switching cycles)
Switch bouncing Arcing across
contacts
Motor Control: Choosing Relay Current Rating
Motor Control
DC SupplyVoltage
(V)
LO-speedCurrent
(A)
MED-speedCurrent (A)
HI-speedCurrent
(A)12.0 5.7 8.6 15.012.5 5.9 8.9 15.613.0 6.2 9.0 16.113.5 6.4 9.3 16.914.0 6.6 9.5 17.414.5 6.8 9.8 18.015.0 7.1 9.9 18.7
Blower motor current draw (low, medium, and high speeds)
Note: Highlighted values are interpolated values due to limitations in test equipment.
Motor Control: Choosing Relay Current Rating
Motor Control
Condenser Fan Motor Current Draw
DC SupplyVoltage
(V)
Motor Current
(A)12.0 7.012.5 7.513.0 7.913.5 8.214.0 8.714.5 9.115.0 9.4
Note: Highlighted values are interpolated values due to limitations in test equipment.
Motor Control
P/S section: 3.3V 5V Items Drawing Current
6.5 mA – MCU 50 uA – LCD driver795 uA – Temperature sensors (3 x 265uA)
Total per section: 10.8 mA 50 uADesign current limit:
10 mA 1 mA
P/S efficiency: 91 % 84 %
Power
Current Draw
Power
3.3V P/S EFFICIENCY 5V P/S EFFICIENCY
Power
Load
SupplyVoltage
(V)
SupplyCurrent
(mA)3.3V OutputCurrent (mA)
5V OutputCurrent (mA)
Efficiency (%)
Minimum 12 13 11.3 9.77 55.215 12 11.3 9.83 48.0
Medium 12 11 12.2 6.39 54.715 10 12.2 6.39 48.1
Maximum 12 12 12.8 6.81 53.015 11 12.8 6.81 46.2
Power
Power
The Proposed System
Administrative ContentItem Price
Quantitiy
Paid Total
Microcontroller - MSP430F2274-Q1 Free Sample 1 Yes -Temperature Sensors - ADT7320 $ 4.87 3 No $ 14.61 PCB by 4PCB.com $ 33.00 1 No $ 33.00 LCD Display - Lumex LCD-S401C39TF Free Sample 1 Yes -LED for User Interface Owned 8 Yes -Push Buttons for User Interface $ 0.19 5 No $ 0.95 Dual Differential Driver - DS90LV027AQMA Free Sample 2 Yes -Dual Differential Receiver - DS90LV028AQMA Free Sample 2 Yes -Shielded Twisted Pair - C1352-100-ND $ 66.96 1 Yes $ 66.96 NPN transistor 200mA ICmax, 40V Vce(breakdown), through hole
$0.17 10Yes $ 1.74
Switching Regulator - TI LM26003 Free Sample 3 Yes - Relay automotive SPST 12V, 15A $1.79 6 Yes $ 10.74 Relay automotive SPST 12V, 30A $5.02 2 Yes $ 10.04 Capacitors $2.50 65 $ 17.47 Diode, Schottky 40V 30mA, through hole $0.66 5 Yes $ 3.30 Inductor 1mH, 10% through hole $2.79 3 Yes $ 8.37 Resistors $0.72 77 Yes $ 6.79 TSSOP-20 to DIP-20 SMT Adapter (for TI LM26003 chip) $4.49 2 Yes $ 8.98 TOTAL $ 182.95
Research
Design
Fabrication
Coding
Testing
Parts Ordered
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Progress
Noise from motors induced into MCU◦ Possible Solutions: Filters, bypass capacitors,
optocouplers Multiple Temperature Sensors Sharing One
SPI Interface.
Concerns
Questions?