Masters Theses


Asha Patel


"Current measurement has many applications in power electronics and motor drives. Current measurement is used for control, protection, monitoring, and power management purposes. Parameters such as low cost, accuracy, high current measurement, isolation needs, broad frequency bandwidth, linearity and stability with temperature variations, high immunity to dv/dt, low realization effort, fast response time, and compatibility with integration process are required to ensure high performance of current sensors. Various current sensing techniques based on different physical effects such as Faraday's induction law, Ohm's law, Lorentz force law, magneto-resistance effect, and magnetic saturation are studied in this thesis. Review and examination of these current measurement methods are presented.

The most common current sensing method is to insert a sensing resistor in the path of an unknown current. This method incurs significant power loss in a sense resistor at high output currents. Alternatives for accurate and lossless current measurement are presented in this thesis. Various current sensing techniques with self-tuning and self-calibration for accurate and continuous current measurement are also discussed. Isolation and large bandwidth from dc to several kilo-hertz or mega-hertz are the most difficult, but also most crucial characteristics of current measurement. Electromagnetic-based current sensing techniques, which are used to achieve these characteristics, are analyzed. Many applications require average current information for control purposes. Different average current sensing methods of measuring average current are also reviewed."--Abstract, page iii.


Ferdowsi, Mehdi

Committee Member(s)

Chowdhury, Badrul H.
Corzine, Keith, 1968-


Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering


University of Missouri--Rolla

Publication Date

Fall 2007


xi, 110 pages

Note about bibliography

Includes bibliographical references (pages 125-127).


© 2007 Ashaben Mehul Patel, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Electric currents -- Measurement

Thesis Number

T 9273

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