Automated system for power measurement in the silent discharge

With the increased interest in improving the conversion efficiency of silent discharges for ozone generation, there is a need for an accurate and convenient technique to measure the power consumed in this process. Normally, the power consumption of an AC silent discharge is measured by using a wattmeter on the low-voltage side of the input transformer. However, this measurement includes the transformer losses, which generally are nonlinear and may account for a significant proportion of the total power loss. Alternatively, the power loss in the silent discharge alone may be calculated by means of results obtained from the oscillograms of the charge-versus-voltage (q-v trace) method or by sampling the discharge current and high-voltage signals. However, the measuring accuracy of these methods is limited, and they are not convenient to use in practice. This paper presents a versatile, automated system for power measurement in an AC silent discharge. The system combines high-accuracy A/D data acquisition technology with the q-v trace method. Experimental results and analysis are presented to show the improved accuracy, speed of response and convenience over conventional measuring methods. The method discussed here is applicable to power measurement in similar discharges, such as AC corona discharges, etc.