Power Analyzers & Motor Drive Analyzers

This brief summarizes how to correctly compare Yokogawa’s power analyzer instrument to the Teledyne LeCroy Motor Drive Analyzer and to explain any differences in measurement results between the two instruments.

With this method, the calculated power values from each line-line voltage and line-neutral current pair are not in phase or balanced, though the total three-phase power value is correct. Accurate line-to-line to line-neutral conversion aids in understanding proper three-phase system operation.

Traditional power analyzers provide only a static mean measurement capability for very short waveform acquisitions, Teledyne LeCroy’s Motor Drive Analyzer provides static and dynamic power analysis coupled with long acquisition times for comprehensive analysis of the motor drive’s performance and efficiency.

Thorough characterization and analysis of a brushless DC motor and itsassociated drive circuitry requires the ability to view waveforms during dynamic events and to visualize the measurements over time.

Motor drive control system debugging often requires the ability to view control and power waveforms concurrently during dynamic events to understand cause and ffect relationships, and visualize the dynamic power behaviors over time, correlated to control activity.

Analog torque load cells and analog tachometers are often used to measure torque and speed with calculation of mechanical power. Traditional power analyzers provide only a static mean measurement capability, but Teledyne LeCroy’s Motor Drive Analyzer provides static and dynamic power analysis and long acquisition times for comprehensive analysis.

More than 90% of motor and motor-drive designs involve small, low-power motors and drives used in household, commercial, or light industrial applications. The Teledyne LeCroy Motor Drive Analyzer can measure drive and motor efficiency of these small motors at a bench without an expensive and/or scarce dynamometer.

The Teledyne LeCroy Motor Drive Analyzer (MDA) dynamically measures per-cycle power and harmonic distortion values, plots them as Waveforms, and permits easy correlation of these values to drive AC input waveforms.

Deadbeat-direct torque and flux control (DB-DTFC) is an alternative to Vector FOC to achieve fast torque control. Evaluating the Volt-second sensing accuracy requires a precise measurement of Volt-seconds as the reference. Teledyne LeCroy's Motor Drive Analyzer provides such capabilities over each power-semiconductor switching period.

Understanding the complete motor and drive electrical operation on a per-phase basis can aid in understanding how the motor and drive react as load conditions change

The Motor Drive Analyzer captures voltage and current signals from both winding sets, measures total static and dynamic power consumption, and calculates balance amongst the two winding sets.

The Motor Drive Analyzer is used to measure dynamic (transient) losses to enable better understanding of motor and drive efficiencies during real-world operation. Additionally, core and copper losses are calculated and compared to engineering models and the drive control feedback circuit.

The Motor Drive Analyzer is used to calculate static and dynamic energy consumption in Joules, and to compare results for different types of motors and control systems.

The Motor Drive Analyzer is used to calculate power during very short time periods during a rotor magnetization, controlled energy pulse trajectory for a variable flux motor to ensure proper operation of the motor drive and control system

The Motor Drive Analyzer acquires the Quadrature Encoder Interface (QEI) A, B and Z index signals and converts them to static and dynamic motor shaft speed and angle values

The Motor Drive Analyzer uses the resolver sine, cosine and excitation frequency signals to to calculate motor shaft speed, angle and absolute position.

The Motor Drive Analyzer is used to acquire CAN digital data, extract relevant motor speed digital information and convert it to an analog motor speed value that is displayed as a speed vs. time waveform.

An example is described of programming the CA10 current sensor adapter to connect a Danisense flux-gate current transducer to a Teledyne LeCroy oscilloscope or Motor Drive Analyzer with results correctly scaled in ampere units

An example is described of programming the CA10 current sensor adapter to connect a Pearson current transformer to a Teledyne LeCroy oscilloscope or Motor Drive Analyzer with results correctly scaled in ampere units.

An example is described of programming the CA10 current sensor adapter to connect a PEM-UK Rogowski coil to a Teledyne LeCroy oscilloscope or Motor Drive Analyzer with results correctly scaled in ampere units.

An example is described of programming the CA10 current sensor adapter to connect an AC current transformer to a Teledyne LeCroy oscilloscope or Motor Drive Analyzer with results correctly scaled in ampere units.