Precision Power Scope combines oscilloscope and power analyser

January 15, 2014 // By Christoph Hammerschmidt
A complex mix of renewable and conventional energies in the grid, electric and hybrid vehicles, aggravated standby power consumption regulations and faster-switching semiconductors with all the consequences for harmonic distortion - these are just some examples out of the complex problem definition designers in the field of power electronics have to deal with today. In such an environment, exact measurement of all power-related parameters in an electronic circuit becomes an important requirement in many designs.

Yokogawa has developed a new power scope that enables developers to carry out these measurements. With the PX8000 the company addresses R&D activities in a broad range of applications, from renewable power to robotics, inverter and motor testing and wireless power charging, explains Clive Davis who oversees Yokogawa's test and measurement products marketing activities in Europe and Africa. "Since more and more innovations are related to energy efficiency and the integration of electronic controls into power systems, engineers need to be able to conduct power measurement with ever-higher exactness and precision", Davis says.

With its combination of oscilloscope and power analyser, the PX8000 enables users to measure power, efficiency, transient responses and many parameters that cannot be measured by available instruments, Davis claims. "Traditional power measurement instruments cannot provide accurate time measurements; oscilloscope are not designed to measure power", he explains. While, for instance, a power computation out of the measurement of voltage and current, does not take in account the phase displacement between both parameter under reactive loads, the PX8000 provides calibrated power measurements even with this kind of load. Its high bandwidth of 20 MHz enables measurement of inverter pulse shapes, facilitating the optimization of such products. The simultaneous acquisition of current and voltage enables power measurement even of transients in real-time. In addition, the instrument offers integrated functions to calculate derived parameters such as root mean square (RMS) values and mean values to detect trends from period to period. A start-stop cursor enables users to analyse power curves over a predefined time space - particularly useful for the analysis of transient processes. Like the vendor's digital oscilloscopes, the PX8000 has a history function which stores up to 1.000 signal values. This function can be used to analyse sporadic signals but also to define trigger conditions. In addition, the history memory can be searched for defined conditions. "This is very useful to identify abnormal phenomena during that otherwise