This paper develops a model for relating input current harmonic content to real power consumption for variable electronic loads, specifically for loads' actively controlled inverters energized by an uncontrolled rectification of the utility. This model serves as the basis for a method for estimating and disaggregating the power consumption of variable speed drives (VSDs) and rectifier loads from other constant power loads. This method can be used for nonintrusive power monitoring. The approach described in this paper uses the approximate switching function of the rectifier to derive the best estimating function for the fundamental current harmonic from a finite set of current harmonics uniquely associated with the operation of the drive. Experimental results show that the proposed VSD power and harmonic estimator can track VSD power consumption for monitoring given knowledge or an estimate of the input current harmonic content.

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Many proposals for future power systems for warships are extant. Anticipated improvements in capability, operating economy, and signature reduction may not be uniquely associated with these power systems. Alternatives are available for constructing variable speed drives and prime movers for ships with electric drives. These alternatives may open new design possibilities.

Abstract-Harmonic analysis of motor current has been used to track the speed of motors for sensorless control. Algorithms exist that track the speed of a motor given a dedicated stator current measurement, for example [1][2][3][4][5]. Harmonic analysis has also been applied for diagnostic detection of electro-mechanical faults such as damaged bearings and rotor eccentricity [6][7][8][9][10][11][12][13][14][15][16][17]. This paper demonstrates the utility of harmonic analysis for fault detection and diagnostics in non-intrusive monitoring applications, where multiple loads are tracked by a sensor monitoring only the aggregate utility service. An optimization routine is implemented to maintain accuracy of speed estimation while using shorter lengths of data. I. SMART MONITORINGAt any point in the life of a system, mechanical and electrical equipment may be poorly operated. For example, as buildings age, both the electro-mechanical actuators and associated mechanical components wear, cease to function properly, and eventually fail, via myriad processes that are often undetected. Valves do not close fully, filters clog, airconditioning system dampers stick, refrigerant leaks, heating and cooling coils -from the smallest refrigerator to the largest building air-conditioning system -become fouled with dirt and debris, and belts slip. Energy waste and excessive plant wear are often exacerbated by closed-loop control. Under active control, damaged but still functioning equipment will operate by extending run times or operating points to meet user commands, leaving few obvious signs of compromised operation.For example, a number of surveys of airflow faults in buildings hint at the range and extent of these problems. One compendium of fault surveys [18], which examined 503 rooftop air-conditioning units in 181 buildings in five states in the Western U.S. from [2001][2002][2003][2004], found that the airflow was out of the specified range in approximately 42% of the units surveyed. A separate study [19] of 4, 168 commercial airconditioners in California reported that 44% of the surveyed units had airflow that was out of specifications. Studies of 29 new homes in Washington State [20] found that average duct leakage rates to the exterior ranged from 687 to 140 cubic feet per minute (CFM). Extrapolating from such fault surveys, one estimate for the total energy consumed by duct leakage is $5 billion/year [21].When "failure is not an option," the performance of important electro-mechanical loads on mission-critical systems like warships or power plants is often tracked by dedicated monitoring equipment [22]. An extensive sensing network can provide obvious advantages for fault detection, diagnosis, and prognosis. However, a large sensing network can be expensive and difficult to maintain.Smart Grid and Smart Meter initiatives hope to allow energy providers and consumers to intelligently manage their energy needs through real-time monitoring, analysis, and control of electrical power usage. The U.S. Department of Energy has i...

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