{"product_id":"9781394423767","title":"Magnetic Models for Electric Machines","description":"\u003ch1\u003eMagnetic Models for Electric Machines\u003c\/h1\u003e \u003ch2\u003eFiennes, Jeremy\u003c\/h2\u003e \u003cp\u003e\u003c\/p\u003e\u003cp\u003e\u003cb\u003eThe Magnetic Model approach to Electrical Machines\u003c\/b\u003e \u003c\/p\u003e\u003cp\u003eIts principal advantages are firstly its \u003ci\u003esimplicity\u003c\/i\u003e. The conventional electrical 'd-q-' model for a salient-pole synchronous machine, for instance, involves 10 electric variables, being 5 coil voltages and 5 coil currents. They are related by a 5x5 inductance matrix. Whereas the magnetic model has only two variables: a complex mmf representing the coil currents, and a complex flux that determines the coil voltages. From these the mechanical torque is obtained.  \u003c\/p\u003e\u003cp\u003eThe other main advantage is that since the complex mmf and flux are \u003ci\u003espace vectors\u003c\/i\u003e, they are \u003ci\u003ereadily visualizable\u003c\/i\u003e in physical terms. This is invaluable for beginning students who normally accompany the mathematics without problem, but are often at a loss to grasp what is ”really going on”.  \u003c\/p\u003e\u003cp\u003eA sudden short-circuit on a synchronous machine on the electric approach involves inverting the 5x5 inductance matrix, with laborious mathematics. On the magnetic model the results – including all the torque components – can be written down by inspection with no mathematics at all.  \u003c\/p\u003e\u003cp\u003eDue to its simplicity, the  magnetic model allows quantitative analysis in cases normally only treated descriptively in texts of this level. The dynamic braking of induction machines; the shaded-pole motor; the asynchronous start of a salient-pole synchronous motor with its half-speed 'kink'; and so on. The inclusion of a rotor eddy-current factor in the conventional induction machine model allows the IEC design class torque\/speed characteristics to be reproduced, otherwise impossible. A novel mathematical technique enables both axes of a salient-pole device to be treated in a single circuit.   \u003c\/p\u003e\u003cp\u003eAttention is paid to the practical aspects of design and testing, often neglected in comparable texts. There are ample worked examples – in principle one for each theoretical point – that with different numeral values can serve as a basis for student exercises.\u003c\/p\u003e \u003ch3\u003eDetails\u003c\/h3\u003e \u003cp\u003ePublished by: Wiley-IEEE Press\u003c\/p\u003e \u003cp\u003ePublication Date: 2026-12-03\u003c\/p\u003e \u003cp\u003eFormat: Hardcover\u003c\/p\u003e \u003cp\u003eISBN-13: 9781394423767\u003c\/p\u003e \u003cp\u003eDOI: \u003c\/p\u003e \u003cp\u003eDimensions: cm xcm\u003c\/p\u003e \u003cp\u003ePages: 544\u003c\/p\u003e ","brand":"Wiley","offers":[{"title":"Default Title","offer_id":50292521828492,"sku":"9781394423767","price":112.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0710\/9545\/1788\/files\/9781394423767.jpg?v=1779932215","url":"https:\/\/lateknightbooks.com\/products\/9781394423767","provider":"Late Knight Books and Services, LLC","version":"1.0","type":"link"}