Motor drive analysers leverage oscilloscope platform

Using new OscilloSYNC technology, two MDA 8000HD instruments comprise a 16-channel analyser—twice the number of channels previously available—with a large 15.6in. display.

Like the earlier MDA800A, this iteration performs comprehensive static and dynamic 3-phase electrical and mechanical power analysis and complete test coverage of the entire motor-drive system.

Ubiquitous and growing in complexity, motors and drives are increasingly optimised for dynamic operating conditions. Traditional power analyser instruments have not kept up with industry needs for dynamic power analysis.

At the same time, oscilloscopes are the traditional tool for gaining insight into embedded control system operation. The two instruments operate in different domains, making it difficult to correlate their respective data sets and leaving large gaps in engineers’ knowledge of system operation.

To close that knowledge gap, the MDA 8000HD captures waveforms from the drive’s three-phase power conversion section; individual power transistors; motor speed, angle and torque sensors; and the embedded control system, while performing coincident three-phase electrical and mechanical power analysis. The MDA performs static (steady-state) power measurements—like a power analyser—and also performs power measurements under dynamic operating conditions.

It then provides per-cycle Waveforms showing power values changing over time. These Waveforms can then be time-correlated using Zoom+Gate functionality and deep acquisition memory to isolate and correlate dynamic events to other power or control-system behaviours.

Power can be analysed during periods as short as a single semiconductor device switching cycle—capability not provided by power analysers but essential for debug of modern motor drive controls.

All of this capability, combined with the synchronised acquisition of up to 16 analog channels, offers complete insight into the entire system.

Teledyne LeCroy’s new OscilloSYNC technology overcoms channel-count barriers by teaming two MDA 8000HD instruments to view and control 16 synchronised analogue channels from a single display and front panel—just like having a single 16-channel acquisition system.

The MDA 8000HD doubles the amount of input channels compared to the previous model, enabling:

• Complete 3-phase AC input, DC bus, 3-phase drive output, plus mechanical power output and efficiency calculations; requires 16 analogue channels.
• Automotive torque vectoring applications requiring simultaneous analysis of two 3-phase drive systems plus other signals; requires 12-16 analogue channels.
• Cascaded H-bridge (3-phase) inverter subsection analysis, requiring measurement of six power-semiconductor outputs and six gate-drive signals; some scenarios may add three-phase output signals and one DC bus-voltage signal; requires 12-16 analogue channels.

The MDA 8000HD Motor Drive Analyzers are offered in bandwidths of 350MHz, 500MHz, 1GHz, and 2GHz; with sample rates up to 10GS/s; and with up to 1.25 Gigapoints of acquisition memory on each channel (5 Gigapoints interleaved). Availability is 6-8 weeks ARO.