Adam Ruszczyk and Krzysztof Sokalski
The purpose of this paper is to present modelling of power losses dependences on temperature in soft magnetic materials exposed to non-sinusoidal flux waveforms and DC bias…
Abstract
Purpose
The purpose of this paper is to present modelling of power losses dependences on temperature in soft magnetic materials exposed to non-sinusoidal flux waveforms and DC bias condition.
Design/methodology/approach
Scaling theory allows the power loss density to be derived in the form of a general homogeneous function, which depends on the peak-to-peak of the magnetic inductance ΔB, frequency f, DC bias HDC and temperature T. The form of this function has been generated through the Maclaurin expansion with respect to scaled frequency, which suit very much for the Bertotti decomposition. The parameters of the model consist of expansion coefficients, scaling exponents, parameters of DC bias mapping, parameters of temperature factor and tuning exponents. Values of these model parameters were estimated on the basis of measured data of total power density losses.
Findings
The main finding of the paper is a unified methodology for the derivation of a mathematical model which satisfactorily describes the total power density losses versus ΔB, f, HDC, and T in soft magnetic devices.
Research limitations/implications
Still the derived method does not describe dependences of the power density loss on shape and size of considered sample.
Practical implications
The most important achievement is of the practical use. The paper is useful for device designers.
Originality/value
This paper presents the algorithm which enables us to calculate core losses while the temperature is changing. Moreover, this method is effective regardless of soft magnetic material type and the flux waveforms as well as the DC bias condition. The application of scaling theory in the description of energy losses in soft magnetic materials justifies that soft magnetic materials are scaling invariant systems.
Details
Keywords
Minh Tran and Dayoon Kim
The authors revisit the notion of co-production, highlight more critical and re-politicized forms of co-production and introduce three principles for its operationalization. The…
Abstract
Purpose
The authors revisit the notion of co-production, highlight more critical and re-politicized forms of co-production and introduce three principles for its operationalization. The paper’s viewpoint aims to find entry points for enabling more equitable disaster research and actions via co-production.
Design/methodology/approach
The authors draw insights from the authors’ reflections as climate and disaster researchers and literature on knowledge politics in the context of disaster and climate change, especially within critical disaster studies and feminist political ecology.
Findings
Disaster studies can better contribute to disaster risk reduction via political co-production and situating local and Indigenous knowledge at the center through three principles, i.e. ensuring knowledge plurality, surfacing norms and assumptions in knowledge production and driving actions that tackle existing knowledge (and broader sociopolitical) structures.
Originality/value
The authors draw out three principles to enable the political function of co-production based on firsthand experiences of working with local and Indigenous peoples and insights from a diverse set of co-production, feminist political ecology and critical disaster studies literature. Future research can observe how it can utilize these principles in its respective contexts.