Electric Two-Wheeler

Sponsors	Dr.Herb Hess & Dr.Joseph Law
Team Name	King of the Hills
Duration	Spring 2019 - Fall 2019
Mentor	Dr.Herb Hess Dr.Joseph Law
Team Members	Val Wold Armando Solis Hai Huang

The goal of the project is to design a controller for an alternator being used as a motor. As proof of concept, the entire system will be mounted on a bicycle to assess its performance in the rolling terrain of the Palouse.

Problem Definition

Design a motor controller that will test the limits of an alternator as a motor; compare its motor capabilities to its generator capabilities.

The first proof of concept is a DC generator load for fine control of steady state power output. The second proof of concept is an Electric Vehicle load to test our controller under heavy transients.

Specifications

Alternators have good power density and cost-effectiveness as generators. These power values will give us the specifications for our performance standards when running our alternator as a motor. The controller design will have to be determined through capable modeling and experimentation.

However, the only initial requirement is that the system performs. That is, by any means available the controller should be able to start and reliably power the alternator under load. From here, we will be able to improve our design, bringing the performance values closer to those of the generator.

Project Learning

Implementation in c
Scheduling, fastest to slowest:

• PWM counter (〖𝑓𝑟𝑒𝑞〗_𝑠𝑤=80𝑀𝐻𝑧/(𝑐𝑜𝑢𝑛𝑡𝑠 𝑝𝑒𝑟 𝑑𝑢𝑡𝑦 𝑐𝑦𝑐𝑙𝑒))
• Space Vector PWM updater (𝑓𝑢𝑛𝑑𝑎𝑚𝑒𝑛𝑡𝑎𝑙/𝑟𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛)
  𝑟𝑒𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛=(𝑠𝑚𝑎𝑙𝑙𝑒𝑠𝑡 𝑠𝑡𝑒𝑝 𝑖𝑛 𝑑𝑒𝑔𝑟𝑒𝑒𝑠)/360
  Example: 50Hz fundamental (1500 RPM), 3 degree smallest step, 6 kHz updates
• Frequency updater
  Change the fundamental frequency
  Change the fundamental frequency
  Example: 50 Hz to 60 Hz using a push-button

Fixed point multiplication

• Example: divide 50 by pi
• First, express 𝜋^(−1) as a multiple of 2^(−11)
  1/𝜋≅652∗2^(−11)
  50/𝜋≅50∗652∗2^(−11)=(50∗652)≫11=15.918
  Actual answer: 50/𝜋=15.9155
  Dividing by powers of 2 is simply a right shift
• Maximizing resolution
  16-bit architecture
  Q-number format
  Moving the point to where as many fractional bits are assigned as possible but no more

Final Design

Picture	Info
Source: Microchip®, Sensorless Field Oriented control of a PMSM Source: Microchip®, Sensorless Field Oriented control of a PMSM	FOC in two minutes Control is actually quite simple Objective: make rotor field orthogonal to stator field AC machines are quite nonlinear if controlled in a stationary, three phase, reference frame Some reference-frame shifting can yield not only steady state DC values but the dynamics are actually decoupled.
	Data flow diagram
	Space Vector Theory Not phasors: Phasors: Describe a single sinusoidal output, with the same frequency as the reference, but with variable magnitude and phase SpaceVectors: Describes three sinusoidal output, all with the same phase relation, but with variable magnitude and position Switching states: Each possible combination of the switching states is a unit vector in voltage space (for a voltage regulator) or current space (for a current regulator) Using switching times to weight these states allows for precise control over the position of the three-phase signal

Validation

Method	Result
Python SVM Simulation	67degrees 145degrees
MPLAB	67degrees 145degrees
Oscilloscope	67degrees 145degrees
Compare Three Methods	67degrees 145degrees

Team Members

Picture	Info
	Vol_Wold Major: Elecrtical Engineering Hometown: Coeur d'Alene, ID Responsibility: Leader Email: wold0156@vandals.uidaho.edu
	Armando_Solis Major: Elecrtical Engineering Hometown: Caldwell,ID Responsibility: Budgeter Email: soli8592@vandals.uidaho.edu
	Hai_Huang Major: Elecrtical Engineering Hometown: China Responsibility: Wikipage supervisor Email: huan2458@vandals.uidaho.edu

Additional Documentation

Meeting Minutes

File:2-27-2019 Minutes.pdf
File:3-6-2019Minutes.pdf
File:3-20-2019Minutes.pdf
File:3-27-2019Minutes.pdf
File:4-3-2019Minutes.pdf
File:4-10-2019Minutes.pdf
File:4-24-2019Minutes.pdf

Tech Presentation
File:Tech presentation.pdf

Machine Test

Picture	Name	Description
	Machine Test	Magnetization Curve Test Procedure: Turn the machine at constant speed and record Ea as a function of If. Results: gives data to the constant relationship between Ea and ω for all pre-saturation values of If. Rotor and Stator Tests Procedure: Place AC and DC on rotor or stator and use the resulting current outputs to determine Ls, Lr, Rs, and Rr.

Simulation

Picture	Name	Description
	simulink	Matlab, simulating different synchronous machines to observe date of machine. The purpose is to help us to build control system.
	simulink	Rotating Space Vector Stationary Space Vector
	simulink	Phases B and C should be shifted by -120 degrees and 120 degrees, respectively PWM is a form of frequency modulation, thus the fft of the PWM signal should resemble FM spectral characteristics If these yield the correct results, we can conclude that the SVM algorithm generates correct switching times

Microcontroller

Picture	Name	Description
	Microcontroller	Model: dSPIC33EV Application: Motor control via the PWM Module Features: 16-Bit Architecture Pin Count: 28 Six Pulse-Width Modulation Outputs

Snapshot

File:SnapshotBudget.pdf