Efficient Motor Control and Power Conversion System Team MotorBoard Critical Design Review 24 February 2009 Nicholas Barr, Daniel Fargano, Kyle Simmons, Marshall Worth

Overview Purpose & SpecificationsSystem DescriptionController CircuitPower ConverterOther parts and purchasesUpdated Labor DistributionUpdated detailed scheduleQuestions/Suggestions and Comments

Purpose and Specifications Provide a general purpose motor power system and controller More specifically will be used in the IEEE Future Energy Challenge ‘09 30 N-m Cold Torque 3000 Rpm 3-5 seconds 1 KW Power NEMA Frame 56

Motor Requirements

Torque Characteristics

System Description Control System Arm7 Microcontroller Built in PWM Gate Drivers for IGBTs Power System Bi-Directional Buck- Boost Converter, more efficient by isolating the buck and boost sections 3-Phase Voltage Inverter

System Diagram

Control System LPC-P2148 Olimex devo board Crossworks-ARM NXP LPC2148FBD64-S Program Memory Size:512KB RAM Size:40KB Package / Case:64-LQFP Speed:60MHz Core Processor:ARM7 Data Converters:A/D 14; D/A 1 Core Size:16/32-Bit Interface:I²C, SPI, SSP, UART, USB

Control Algorithm The objective of the controls algorithm is to sense a set of inputs from the motor and control board and produce a corresponding 3-phase output voltage. First we sample the current in phase A,B and C as well as the position and speed of the rotor shaft Second we determine the motor operating mode, motoring or generating, and the desired speed of operation. From these quantities the desired DC-DC converter output voltage and phase A,B and C voltages are calculated. Finally the controller will determine the appropriate duty cycle to emit on the IGBT gate driver input in order to produce the desired voltage at both the output of the DC-DC converter as well as the phase A,B and C voltages produced by the inverter. The objective of the controls algorithm is to sense a set of inputs from the motor and control board and produce a corresponding 3-phase output voltage. First we sample the current and voltage at phase A,B and C of the motor as well as the DC-DC output voltage. Additionally we sample the position and speed of the rotor shaft. Second we determine the motor operating mode and the desired speed of operation. From these quantities the desired DC-DC converter output voltage and phase A,B and C voltages are calculated. Finally the controller will determine the appropriate duty cycle to emit on the IGBT gate drivers’ input in order to produce the desired voltage at both the output of the DC- DC converter as well as the phase A,B and C voltages produced by the inverter.

Vector Controller

Clark Transform

Park Transform

PWM

CrossWorks Code written for Development board using CrossWorks

Power System 195VDC line to supply from variable AC source Large DC supply line capacitor Bidirectional Buck-Boost Converter Bidirectional DC  3- phase AC inverter

Power System - Overview

Power System – Cascaded B/B

Power System - 3φ Inverter

Power System – Switches Power MOSFET high-frequency operation low-voltage drop (low power losses) saturation temperature sensitivity IGBT low drive current fast switching time higher voltage drop (higher conduction losses) IGBT w/Diode Co-pack Voltage - Collector Emitter Breakdown (Max):600V Current - Collector (Ic) (Max):85A

Power System – Driver Configuration:High and Low Side, Independent Bootstrap circuit designed to prevent gate voltage from dropping below minimum gate threshold voltage

Power System – Driver

DC-DC Bi-Directional Buck-Boost

Simulated 3 Phase Waveforms

Sensors After attending APEC Dan needs to call his contact at GMW or TEG to get free Hall Effect Sensors 3 Hall-effect current sensors for a,b,c line detection Most likely optical Prefer absolute position sensor Old team lists having this and could possibly find and use theirs Quadrature encoder (fancy shaft encoder) APEC -> Call TEG for possible free sample Resistor Divider Network (Power Loss) DC line voltage sensor Temperature sensor Optional (safety):

Parts List – Mass Production ItemPart #QuantityUnit PriceTotal PriceMass Production Cost Caps ND49.35$37.4$8.35 InductorsM8380-ND19.56$9.56$1.39 IGBTsIRG4PSC71U DPBF $106.80$18.70 DriversIR PBF-ND 55.57$27.85$5.96 BootstrapsXXX51.19$5.95$1.49 MPU ND111.20$11.20$2.80 ControlsXXX131.76$31.76$7.94 MotorBaldor $326.90$50 PackageXXX118.20$18.20$3.64 Total$574.54$100.00

Division Of Labor Converter Nick Marshall Inverter Dan Kyle Software Nick Marshall PCB Design Dan Marshall Custom Footprints Kyle Dan Marshall Testing All Documentation All Presentation All

Project Milestones Milestone I Power Electronics hardware working on perf-board Controls driven by Dev Board (no feed back loops) First revision of controls PCB completed and sent out. Milestone II Power electronics PCB designed and sent out for fabrication Controls PCB built and populated Full controls algorithm with working feed- back loops. EXPO Final debug finished Packaging designed done and project packaged Documentation done

Questions?