Motor-drive power-analyzer software supports HDO8000 scopes

September 30, 2014. Teledyne LeCroy today announced three-phase Motor Drive Power Analyzer software for its HDO8000 oscilloscopes. The HDO8000 mixed-signal oscilloscopes, with eight input channels, 12-bit resolution, and up to 1-GHz bandwidth, are suitable for motor-drive embedded-control and power-section debug. With the addition of three-phase power analyzer capability and motor speed and torque integration, the complete drive system can be more quickly and easily validated and debugged, and extensive drive and motor power and efficiency measurements may be performed.

The HDO8000 and Motor Drive Power Analyzer software will be utilized by designers and manufacturers of motors, motor drives, variable-frequency drives, variable-speed drives, and industrial-automation and motion-control systems. Design engineers that integrate motors into their designs (vehicles, power tools, appliances, elevators, fans, blowers, compressors, pumps, and so on) can utilize the product to validate proprietary controls and complete drive system designs.

Capability for complete drive system validation and debug

A complete drive system is a complex mix of three-phase power electronics, motor/mechanical analog and digital sensors, and embedded controls, with a complex variety of analog, digital, and pulse-width modulated (PWM) signals. Oscilloscopes are able to capture higher speed embedded control system or power transistor activities, but until now, the company said, have been unable to measure drive power and efficiencies. Power analyzers are a single-use tool for measuring input/output “black-box” drive power and efficiencies, but provide limited or no waveform capture for embedded control or drive system debug.

The HDO8000 oscilloscope with Motor Drive Power Analyzer software permits waveform captures from the drive power section, individual power transistors, and embedded control system, and performs coincident three-phase power analysis of the power section waveforms in one high-performance instrument, enabling debug and analysis of all aspects of the complete motor drive.

An intuitive, graphical user interface provides setup/connection guidance. Setup capability is provided for any combination of single-phase or three-phase drive input/output, and supports both two- and three-wattmeter calculation methods and a line-to-line to line-to-neutral voltage conversion. Using the two-wattmeter method, drive input/output and motor output efficiencies can be measured using the eight inputs on the HDO8000 oscilloscope.

Mechanical motor integration

The Motor Drive Power Analyzer software permits simple integration of nearly any type of speed, rotation, or position sensor, including analog and digital (pulse) tachometers, a brushless DC (BLDC) Hall sensor, a Quadrature Encoder Interface (QEI), and resolvers. Additionally, Hall sensor and QEI signals can be integrated through digital inputs, preserving valuable analog input channels for other signals.

Various voltage, current, power (real, apparent, and reactive), phase angle/power factor, and efficiency parameters are calculated on acquired voltage and current waveforms and displayed in a table. The table is user-configurable and is displayed along with the acquisition waveform and corresponds to information normally provided by a power analyzer.

Additionally, a waveform showing any per-cycle measurement parameter variation can be displayed by simply selecting a table value. This waveform is time-correlated with other waveforms acquired by the HDO8000 oscilloscope and can be used to correlate complex drive behaviors to other control or power system waveforms and to debug drive system problems. Statistical detail of the measurement set can also be displayed. This additional information goes well beyond what is provided by a Power Analyzer.

Dynamic drive response analysis

The long acquisition memory in the HDO8000 (up to 250 Mpoints/channel) provides unique capabilities for motor and drive dynamic response analysis. For example, 25 seconds of continuous acquisition capture is possible at a sample rate of 10 MS/s. This permits complete understanding of dynamic drive behaviors, such as startup, application of load, or fast changing load conditions, and correlation of drive response problems to control system instructions or power section failures.

Standard Teledyne LeCroy passive or active voltage probes (passive or active) and current probes may be used for power measurements. In many cases, probes required for embedded control or power section debug can be used for power measurements, making incremental investments unnecessary. Other voltage and current measurement devices (such as potential or current transformers, current transducers, or Rogowski coils) may also be easily and simply integrated to the HDO8000 oscilloscope. 1,000-VRMS isolation is available with Teledyne LeCroy’s HVD Series HV differential probes, with a maximum 2,000-VPK-PK differential voltage rating and 1% gain accuracy.

The Motor Drive Power Analyzer software will sell for $5,000. It will be available for all HDO8000 oscilloscope models (350 MHz, 500 MHz, and 1 GHz).

Beta versions of the new three-phase Motor Drive Power Analyzer software are available in October, with product shipments scheduled for January. Any customer who has already purchased a Teledyne LeCroy HDO8000 oscilloscope may request the beta software. The software beta availability follows worldwide alpha field testing and additional testing in Teledyne LeCroy’s dedicated motor drive lab.

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