Sensorless Vector Control and Implementation: Why and How Renesas Electronics America Inc © 2012 Renesas Electronics America Inc All rights reserved Renesas Technology & Solution Portfolio © 2012 Renesas Electronics America Inc All rights reserved Microcontroller and Microprocessor Line-up 2010 2013 1200 DMIPS, Superscalar 32-bit Automotive & Industrial, 65nm 600µA/MHz, 1.5µA standby 1200 DMIPS, Performance Automotive, 40nm 500µA/MHz, 35µA deep standby 500 DMIPS, Low Power Automotive & Industrial, 90nm 600µA/MHz, 1.5µA standby 165 DMIPS, FPU, DSC Industrial, 40nm 242µA/MHz, 0.2µA standby 165 DMIPS, FPU, DSC Industrial, 90nm 242µA/MHz, 0.2µA standby 8/16-bit 25 DMIPS, Low Power Industrial, 90nm 1mA/MHz, 100µA standby Industrial & Automotive, 150nm 190µA/MHz, 0.3µA standby 44 DMIPS, True Low Power 10 DMIPS, Capacitive Touch Industrial & Automotive, 130nm 144µA/MHz, 0.2µA standby Format Automotive, 130nm WideIndustrial &LCDs 350µA/MHz, 1àA standby Embedded Security, ASSP â 2012 Renesas Electronics America Inc All rights reserved ‘Enabling The Smart Society’ Challenge: Sensorless vector control increases the energy efficiency of motor control systems that drive the smart society However, understanding and implementing sensorless vector control is a herculean task MCU Solution: This class will help you understand key challenges associated with sensorless vector control and how to implement it using Renesas microcontrollers © 2012 Renesas Electronics America Inc All rights reserved Agenda Need for vector control Theory behind vector control Challenges in implementing sensorless vector control RX62T MCU family for sensorless vector control Renesas motor control solutions © 2012 Renesas Electronics America Inc All rights reserved Macro Factors Driving Need for Energy Efficiency Global Environmental Concerns Energy Efficiency Policies New Initiatives © 2012 Renesas Electronics America Inc All rights reserved Realizing Energy Efficiency in Motor Control Industrial 44% Residential 26% Others 30% Motors (45%) Electronic Control Energy Efficient Motors Variable speed drives Motor Design Vector control Motor Type Direct torque control Power factor correction 15% 20% Up to ~30% savings © 2012 Renesas Electronics America Inc All rights reserved Sensorless Vector Control Theory © 2012 Renesas Electronics America Inc All rights reserved Permanent Magnet AC Motor Complex Control Sinusoidal stator current produces rotating field Rotor mounted magnetic field is rotating Γ = k λs × λr Maintain stator field orthogonal to rotor field A X C’ B X B’ θ X C A’ © 2012 Renesas Electronics America Inc All rights reserved A B C Vector Control Challenge Maintain orthogonality Error correction feedback loop – In-phase current = – Orthogonal current set per torque requirements What parameters to adjust Voltage magnitude (PWM duty cycle) Need to transform current vectors to rotor frame Stator Field 900 Rotor Field 10 © 2012 Renesas Electronics America Inc All rights reserved ωr Code Size Floating-point code size is 45% lower Current Measurement Position Estimation Floating Point Clarke and Park Fixed point PI Loop B 43 © 2012 Renesas Electronics America Inc All rights reserved 50 100 150 200 250 Driving Two 3-Phase BLDC Motors Sensorless Vector Control www.renesas.com/rxmotorkit Floating point math CPU BW used (α,β) ->(d,q) Current Reconstruction PWM Interrupt2 Last θ Actual Current Reference Current Last ω & Reference ω Speed PI Current PI Voltage (d,q) New Speed Estimation New θ Estimation V(u,v,w) -> PWM Duty (d,q) -> (α,β) (u,v,w)