A Servo Motor is a closed-loop servomechanism that uses position feedback (like encoder) to control its motion and final position. The input to its control is a signal (either analogue or digital) representing the position commanded for the output shaft.
Servo Motors are used in radio-controlled airplanes to position control surfaces like elevators, rudders, walking a robot, or operating grippers.
Servo Motor advantages:
- Excel at position and speed control.
- High output power relative to motorsize and weight.
- Encoder determines accuracy and resolution.
- High efficiency. It can approach 90% at light loads.
- High torque to inertia ratio. Servo Motors can rapidly accelerate loads.
- Servo motors achieve high speed at high torque values.
- Quiet at high speeds.
Servo Motor disadvantages:
- Requires tuning to stabilize the feedback loop.
- Will become unpredictable when something breaks, so safety circuits are required.
- Complex controller requires encoder and electronic support.
- Peak torque is limited to a 1% duty cycle. Servo Motors can be damaged by sustained overload.
- Gear boxes are often required to deliver power at higher speeds.
- Higher overall system cost and the installation cost of a Servo Motor system may be higher than that of a stepper motor due to the requirement for feedback components.
Servo motor testing Features:
- The MEA regenerative Dynamometer System (MEA RDS) enables:
- Complete load performance testing: Torque, Speed, Current, Efficiency, Power Input, Power Output.
- Standard electrical parameters testing: HV, Vibration, Noise, and others.
- Additional testing: Cogging, Back EMF, Friction, Friction Spectrum, Ripple Torque.
- Automatic temperature rise test: Thermocouple device with 4 to 16 channels, Current, Voltage, Speed, Torque, Input Power, Output Power, all synchronized to each temperature.
- Electrical Motorcycle Motor Drive Cycle Load Simulation: Real-time simulation of scooter/driver, with acceleration, brake, change of vehicle states.
- Battery Simulation: Battery cycle testing (Charge/Discharge), Battery SOC (State Of Charge) script and Battery SOD (State Of Discharge) script, during advanced battery simulation and simple battery simulation; Special feature: Low voltage dip at current transient; System includes Output Filter with high capacitance; Testing at U mode: Voltage Control (CV).
- Battery Testing: I+ mode: Current Control (CC+); I- mode: Current Control (CC-); P mode: Power Control (CP), CC-CV, Step for cut-off condition (ET, EV, EC, CC time, CV time, Cap%, etc..), Protection (OV & LV, OC & LC, OT).
- Additional EM Tests: Performance Generating Mode & Performance Motoring Mode, Stall Torque, Cogging Torque, Back EMF RMS, Open Circuit Back EMF, Back EMF Constant KE, No Load Coupled & Uncoupled, Torque Ripple Measurements at Low RPM & at High RPM, Electromechanical Time Constant, Voltage and Current Harmonics, Load from Excel File, Speed Torque Scope Viewer, Deceleration Test (MOI Calculation), Servo Bandwidth (Speed Loop & Current Loop), Dynamic Testing during acceleration and deceleration, Friction vs. Speed & Friction Drag Torque, Torque Speed FFT, Performance at Variable Voltage, Inductance Test 3 Phases, Vibration; ISG Tests: Generation Characteristic; ISO Efficiency Tests: ISO Efficiency and ISO Efficiency Contour, S1 to S8 – IEC duty cycles of operation for electrical motors.