Energy management method for a locomotive including single-sided linear induction motors

For a railway locomotive including a source of electrical energy, a primary traction mechanism for converting electrical energy to tractive effort including a locomotive wheel supported on a ferrous rail and an electrically powered traction motor connected to rotatably drive such wheel, and a supplemental energy conversion mechanism for increasing the effective adhesion between the locomotive wheel and the rail including at least one electrically activated single-sided linear induction motor (SLIM) suspended from the locomotive in close proximity to the rail, a method of operating the supplemental energy conversion mechanism comprising the steps of:

• determining a maximum effort term representative of the tractive effort that should be developed by the traction motor when there is an optimal level of adhesion between the locomotive wheel and rail, such maximum effort indication being determined as a function of the speed of the locomotive and the setting of an operator manipulated power controller;
• determining an actual effort term representative of the tractive effort actually developed by the traction motor;
• activating the SLIM when the relative values of said maximum and actual effort terms indicate that the tractive energy conversion capability of the primary energy conversion mechanism is being limited by less than optimal adhesion between the locomotive wheel and rail, thereby to effectively increase the adhesion between the locomotive wheel and rail;
• and thereafter
• deactivating the SLIM when the relative values of said maximum and actual effort terms indicates that the primary energy conversion mechanism is no longer being limited by less than optimal adhesion.

For a railway locomotive having an engine source of mechanical energy governed by an operator manipulated power control setting, a primary energy conversion mechanism including a locomotive wheel supported on a ferrous rail, an electric traction motor connected to rotatably drive such wheel, and a primary engine driven electrical generator for producing electrical energy to operate such traction motor, and a supplemental energy conversion mechanism including at least one electrically activated single-sided linear induction motor (SLIM) suspended from the locomotive in close proximity to the rail, and a supplemental engine driven electrical generator for producing electrical energy for activating such induction motor for increasing the effective adhesion between the locomotive wheel and rail, a method of operating the supplemental energy conversion mechanism comprising the steps of:

• detecting the existence of an operating condition for which the energy conversion capability of the primary conversion mechanism is limited due to less than optimal adhesion between the locomotive wheel and the rail;
• and
• comparing a measure of the electrical power output of the primary generator with a maximum power reference corresponding to the maximum power output the engine is capable of developing at the power control setting, thereby to develop a signal indicative of the reserve power potential of the engine;
• developing a power requirement signal in accordance with the combination of (1) the engine power required to fully energize the SLIM, and (2) the engine power required to increase the energization of the traction motor with the improved adhesion brought about by energization of the SLIM;
• and
• developing a control signal for the supplemental engine driven generator in accordance with a ratio of the reserve power potential signal to the power requirement signal, such that when the SLIM is energized in accordance with the control signal, the combined additional power requirements of the SLIM and traction motor do not exceed the reserve power potential of the engine.