Jason M. Anderson

An on-line fault diagnosis method for power electronic drives

This paper describes online techniques for monitoring the health of the two most sensitive components in power electronic systems, namely electrolytic filtering capacitors and controllable semiconductor switches (i.e. MOSFETs and IGBTs). The paper begins with a brief discussion of the primary failure mechanisms for these two types of components. It then presents an online technique designed to measure capacitor ESR, which is a key indicator of capacitor health. Subsequent sections address similar online approaches for tracking the on-state resistance of MOSFETs and the collector-to-emitter saturation voltage of IGBTs. Experimental results demonstrate the effectiveness of these techniques.

Creating low-cost energy-management systems for homes using non-intrusive energy monitoring devices

This paper demonstrates how non-intrusive energy monitoring systems can be used to create powerful low-cost energy-management systems for use in homes. The paper describes the basic operation of non-intrusive devices, and it places particular emphasis on their ability to detect equipment degradation using only aggregate current measurements. The method used for detection of loads is described in detail. Also several field tested diagnostics that were developed to detect equipment degradations are presented.

On-line condition monitoring for MOSFET and IGBT switches in digitally controlled drives

The early detection of incipient faults is desirable in mission-critical applications such as shipboard propulsion drives. This paper presents an on-line condition-monitoring approach for detecting incipient faults in IGBTs and MOSFETs. The proposed algorithm extracts important device features (i.e VCE,ON and RDS,ON) and compares them to healthy values recorded over a range of operating conditions. The algorithm is based on principal-components analysis (PCA). An experimental implementation in an IGBT-based drive is described. An on-line feature extraction scheme for MOSFETs is also proposed and demonstrated. This scheme exploits the nature of carrier-based PWM in order simplify the measurement process.

Online algorithm for early stage fault detection in IGBT switches

The early detection of incipient faults is desirable in mission-critical applications such as shipboard propulsion drives. This paper presents an online condition-monitoring approach for detecting early stage faults in IGBTs. The proposed algorithm extracts important device features (i.e. on-state resistance, gate charge, etc.) and compares them to healthy values recorded over a range of operating conditions. The algorithm is based on principal-components analysis (PCA). An experimental implementation in an IGBT-based drive is described, and results recorded with two different faults over a range of operating conditions are presented. The scheme integrates well with new FPGA-based gate drives and provides a powerful alternative to rules-based fault detection.

Using smart meters for load monitoring and active power-factor correction

This paper proposes a cost-effective approach to active power-factor correction that uses a smart meter installed at a service entry and a dedicated active power filter. The power circuit could be connected at a conventional 240V AC outlet in a home, or it could be installed at a transformer secondary and coordinate with several downstream meters. The smart meter is a non-intrusive load monitor (NILM) that measures the active, reactive, and harmonic content of the line current. This information is fed to the dedicated active power filter. The NILM determines the amount of reactive and harmonic current fed to the downstream loads, which may include the current supplied by the active power filter itself. Despite this, the reactive current can be reduced to nearly zero. The active power filter can also be provided with external commands from the grid operator. This scheme is particularly useful in virtual power plant (VPP) applications involving demand dispatch in support of distributed intermittent renewables. The paper describes the control scheme needed by the power circuit and presents experimental results.

Diagnostics and prognostics for multiple induction machines using a single set of current transducers

This paper describes a field-tested technique that uses aggregate current measurements to detect faults in multiple induction machines. This new approach reduces costs and potentially increases reliability. The paper begins with a description of the field-tested system. It then describes three analytical techniques that have been applied to aggregate data in order to identify faults. The paper uses specific examples taken from applications in power plants and shipboard environments.

Near real-time incipient fault detection in IGBT switches

The early detection of incipient faults is desirable in mission-critical applications such as shipboard propulsion drives. This paper presents an online condition-monitoring approach for detecting early stage faults in IGBTs. The proposed algorithm extracts important device features (i.e. on-state resistance, gate charge, etc.) and compares them to healthy values recorded over a range of operating conditions. The algorithm is based on principal-components analysis (PCA). An experimental implementation in an IGBT-based drive is described, and results recorded with two different faults over a range of operating conditions are presented. The scheme integrates well with new FPGA-based gate drives and provides a powerful alternative to rules-based fault detection.

Improving the efficiency of residential HVAC systems using computer-based power-electronic controls

Space heating and cooling are responsible for about 43% of energy consumption in the average American home [1]. That number can be reduced significantly through the use of a computer-based power-electronic control system. This paper describes one proposed solution, which uses a PC to control the motors in the system. The central PC uses wireless communications to coordinate fan and compressor speeds. The paper describes some new control concepts designed to implement demand-side management, and it shows how the system can be operated in a diagnostic mode that regularly checks for increased energy consumption resulting from degrading equipment conditions.

Internal characterization of alkaline batteries: Using impedance spectroscopy for parameter identification

A brief overview of the various equivalent battery models will be reviewed, a model will be decided upon in which it will be used to depict internal characteristics of the battery. These characteristics will be correlated to the state of charge of the battery. In this paper, a review of how to obtain the internal parametric of the alkaline batteries will be explained utilizing electrical spectroscopy with the data analyzed by various techniques. Techniques that will be looked into are; Least-Squares fitting, Delta V/Delta I, as well as open circuit voltage correlation to state of charge.

Using voltage distortion measurements for demand-side management

This paper describes a simple system that could form the basis of a load-shaping scheme aimed at relieving distribution congestion in grids with plug-in hybrid electric vehicles (PHEVs). The system identifies the operation of individual loads using transient patterns observed in the voltage waveform measured at an electric service outlet. The system focuses on the detection of all of the large loads connected to the secondary of a distribution transformer.