JEDT 13,2 298 Received 12 February 2013 Revised 28 July 2013 Accepted 2 September 2013 Journal of Engineering, Design and Technology Vol. 13 No. 2, 2015 pp. 298-314 1726-0531 DOI 10.1108/JEDT-02-2013-0014 PSIM simulations of a dc SQUID magnetometer Kehinde Ogunyanda Department of Electrical Engineering, Cape Peninsula University of Technology, Johannesburg, South Africa, and Wilfred Fritz and Robert van Zyl Department of Electrical Engineering, Cape Peninsula University of Technology, Bellville, South Africa Abstract Purpose – This paper aims to report the modelling and simulation work that predicts the behaviours of both a Josephson junction (JJ) and a dc superconducting quantum interference device (SQUID). It is pertinent to predict the SQUID ŮaŨůŦŵŰŮŦŵŦųŴ’ behaviours via simulations, before subjecting them to real experiments because they are quite expensive to acquire, and can be easily damaged during test analysis. Design/methodology/approach – To achieve this, power simulation (PSIM) was used to model and simulate a JJ, using the basic equation that describes the effective current through it. A dc SQUID magnetometer, which is composed of two JJs, was then modelled and simulated using the modelled JJ. Thermal noise simulation is also included, to observe its effects on the ŮaŨůŦŵŰŮŦŵŦų’Ŵ output. A directly coupled flux-locked loop circuit was later included in the simulation to amplify and linearise the SQUŊŅ’Ŵ output, which is usually sinusoidal. Findings – When steady bias currents were applied to the JJ, the resulting voltage across it was seen to oscillate. The ŋŋ’Ŵ and SQUŊŅ’Ŵ voltage– current characteristics, and voltage–flux characteristics were also observed in the simulations, and the results respectively agree with the behaviours of a typical JJ and dc SQUID magnetometer. Originality/value – A way of simulating SQUIDs, without a superconducting simulation tool, is presented. The work provides a much simpler way of studying the behaviour of dc SQUID magnetometers, due to the easy accessibility and fast simulation capability of the software used, with an added advantage of being able to simulate the thermal noise effects, without having to import this facility from secondary software. Keywords Computer simulation, Circuit and systems, Computational electromagnetism, Electromagnetic compatibility, Modelling of electromagnetic devices Paper type Research paper 1. Introduction A superconducting quantum interference device (SQUID) is considered the most sensitive of all known magnetometers, capable of measuring magnetic fields in the femto Teslas range, as reported by Faley et al. (2002). Such weak magnetic fields need to be detected for biomagnetic and space weather applications (NOAA Space WeatherPrediction Center). Regions of the Van Allen radiation belt closer to the ņaųŵũ’Ŵ I want to appreciate the National Research Foundation, and the Department of Science and Technology for the bursary awarded me during the course of this research. The current issue and full text archive of this journal is available on Emerald Insight at: www.emeraldinsight.com/1726-0531.htm