Hobby Scale Dynamometer Description

Motivation

The motivation for the creation of this instrument is borne out of reseach regarding the generation of electricty with wind turbines. Students in the CEFNS department occasionaly construct small research wind turbines and as such, need small generators to fit it the dimunuative chassis inherient to small wind turbines. Since every motor is also a generator, students often employ small motors used in remote-controlled vehicles as generators in their turbine designs. These motors however, have a lack of technical documentation regarding their specific capabilities, information that this critical for an effective wind-turbine design. This instrument fills this information void through profiling "black-box" motors and affording the small wind-turbine designer more technical information regarding their choice of to create a more effective wind-turbine design.

Problem Definition

The team must create a fully functional, bench-top dynamometer.  It must be capable of varying the drive motor voltage, RPM and load across the generator under test.  The dynamometer must characterize the electrical and mechanical torque, create torque-speed curves for the generator under test, be capable of steady-state load testing, transient load testing and report the temperature of the generator windings.  The dynamometer must be capable of testing motors from 50W to 500W, and rated from 200 V/RPM to 2000 V/RPM.  The design must be safe, with appropriate safety measures such as a guard, safety shutoff switches, over-voltage/current protection, and temperature regulation.

System Diagram

Key Requirements and Specifications

-Produce a fully functional bench top hobby scale dynamometer with the following features

-Easy to use control interface that can vary driving motor voltage, RPM, and load (including open circuit)

-Complete user manual with example tests

-Safe design with safety shutdown switch

-Be able to characterize the following:

a. Electrical torque and mechanical torque

b. Generator torque - speed curves

c. Steady state load testing (constant rpm, constant load, and constant voltage)

d. Transient load testing (via a user defined variable load, variable rpm, and variable voltage)

e. Thermal characteristics of generator windings

-Ability to have a range of direct drive and gearbox mounting configurations consistent with this scale of generator.

Last Updated : 4/22/14