RU2031013C1 - Device for distributing generator current between parallel circuits of series wound traction motors of unloaded and loaded wheelsets of diesel locomotive - Google Patents

Abstract

FIELD: locomotive engineering. SUBSTANCE: device has DC electrical machines (motor-generator pair) with separately excited and series field windings. Series field windings of machines are connected in opposition to each other, and contacts of each circuit reversing change-over switches are placed in corresponding circuit to simultaneously change direction of cutting in of traction motor field windings, armature winding and series field windings of corresponding machine of motor-generator pair. This provides definite relationship between polarity of voltage of traction motor armature windings and armature windings of machines of motor-generator pair depending on mechanical loading of traction motors and between direction of current in their field windings. EFFECT: enlarged operating capabilities. 1 dwg

Description

 The invention relates to the field of electrical equipment of vehicles and is intended for diesel locomotives that are equipped with power transmission and operate in shunting mode.

 Closest to the invention in technical essence is a device that contains a motor-generator pair with independent excitation windings, anchor windings connected unidirectionally with respect to each other, series excitation windings and a reversing switch with first and second contacts. The first contacts are included in traction electric motor circuits having a large operating voltage. Through the second contacts of the independent excitation windings of the engine-generator pair are connected to a source of lower control voltage. A known device requires a reversing switch with a large number of contacts, which are included in electrical circuits with different operating voltages. Such a reversible switch is difficult to manufacture, laborious to maintain and does not provide good reliability.

 The essence of the invention lies in the fact that the series windings of the electric machines of the engine-generator pair are connected in opposite directions to each other, and the contacts of the reversing switches are introduced into parallel circuits of the traction motors with the possibility of simultaneously changing the direction of inclusion (current) of their field windings, anchor windings and sequential excitation windings of the engine-generator pair. Such distinctive design features make it possible to reduce the number of contacts in the reversing switch and ensure their inclusion in electrical circuits with one operating voltage (traction electric motor circuits).

 The technical result of the invention is characterized by simplification, reducing the complexity of maintenance and increasing the reliability of reversing switches.

 The drawing shows a circuit diagram of a device for distributing current.

 The device has a traction DC generator 1, traction motors with anchor windings 2 and sequential excitation windings 3, electric DC machines with anchor windings 4.1 and 5.1, sequential excitation windings 4.2 and 5.2, independent excitation windings 4.3 and 5.3 and with a mechanical connection 6 between anchors, chain reversing switches with pairs of closing and opening contactors 7.1-7.4. Windings 4.3 and 5.3 are connected to the control voltage source of the locomotive. On the diagram, dots denote the windings of the same name, arrows indicate the direction of the current, plus and minus signs indicate the polarity of the voltage on the elements of the electrical circuits of the device. Traction motors of one parallel circuit rotate the loaded wheel pairs, the second - loaded. When the direction of motion of the locomotive changes, the electric motors that rotate the unloaded (loaded) wheel pairs before changing the direction of movement, after the change, rotate the loaded (unloaded) wheel pairs. The unloading of some wheelsets and the loading of others occurs under the influence of mechanical overturning moments that occur during the movement of the locomotive.

 Consider the operation of the device for the following conditions. With closed contacts 7.1 and 7.3 and open contacts 7.2 and 7.4 of reversing switches, the locomotive moves in the direction in which the traction motors of the left (right) chain rotate the unloaded (loaded) wheel pairs. The voltage of the generator 1, windings 2, 4.1 and 5.1 has the polarity shown in the diagram; current flows in the windings 4.2, 4.3 5.2, 5.3, the direction of which is shown by arrows. Unidirectional currents flow in the windings 4.2 and 4.3 of the electric machine of the left circuit, the magnetic fluxes of the windings 4.2 and 4.3 add up. This machine operates in motor mode and rotates the anchor of an electric machine of the right circuit. The voltage of the winding 4.1 of the machine-motor is added to the voltage of the windings of 2 traction motors of the left circuit. In the windings 5.2 and 5.3 of the electric machine of the right circuit, multidirectional currents flow, the magnetic fluxes of the windings 5.2 and 5.3 are subtracted, while the magnetic flux of the winding 5.3 prevails. This machine operates in generator mode, the voltage of its winding 5.1 is subtracted from the voltage of the windings of 2 electric motors of the right circuit.

 The voltage of the parallel circuits with the windings of the traction motors and the engine-generator pair is equal to the voltage of the generator 1. Under the action of the voltage of the winding 4.1 of the machine-engine, the current of the left-hand motor decreases and the voltage drop at its resistance becomes less by the magnitude of the voltage of the winding 4.1. Under the action of the voltage of the winding 5.1 of the generator machine, the current of the electric motors of the right circuit increases and the voltage drop at its resistance becomes greater by the magnitude of the voltage of the winding 5.1. With a constant output power of the generator 1, the lower (greater) its voltage and, accordingly, the greater (less) its current, the greater (smaller) the magnitude of the excitation and voltage flows of the windings 4.1 and 5.1 of electrical machines, because their anchors rotate with the same frequency and the current of the windings 4.3 and 5.3 does not change. As a result of this, a correspondence is ensured between the current (traction force) of the electric motors and the mechanical loads of the wheel pairs, which differ by a larger (smaller) value with a larger (lower) current of the generator 1, and an increase in the traction force of the locomotive.

 When the locomotive moves in the opposite direction, contacts 7.1 and 7.3 are open and contacts 7.2 and 7.4 of the reversing switch are closed, the traction motors of the left (right) chain rotate the loaded (unloaded) wheel pairs, the voltage polarity of the generator 1, windings 2 of the traction motors and the current direction in the windings 4.3 and 5.3 electric cars do not change. The current of the winding 4.2 has a direction opposite to that shown in the diagram, the magnetic fluxes of the windings 4.2 and 4.3 are subtracted, the electric machine of the left circuit operates in the generator mode, the voltage of its winding 4.1 is subtracted from the voltage of the windings 2 of the electric motors of the left circuit. A current flows in winding 5.2, the direction of which is opposite to that shown in the diagram, the magnetic fluxes of windings 5.2 and 5.3 add up, the electric machine of the right circuit operates in the motor mode, which rotates the generator machine. The voltage of the winding 5.1 of the machine-motor is added to the voltage of the windings of 2 electric motors of the right circuit.

 Due to such a change in the operating modes of the engine-generator pair when changing the direction of motion of the locomotive when it moves in the opposite direction, the current distribution of the generator 1 between the parallel circuits of the traction electric motors is provided, corresponding to the mechanical loads of the wheelset of the locomotive, and an increase in its traction force.

Claims (1)

 DEVICE FOR DISTRIBUTING THE GENERATOR'S CURRENT BETWEEN THE PARALLEL CHAINS OF TRAINING ELECTRIC MOTORS OF SEQUENTIAL EXCITATION OF UNLOADED AND LOADED WHEEL PAIRS OF THE HEAT CARRIER, containing an auxiliary motor-generator pair of excitation windings to the control windings chains, chain reversing switches made with pairs of make and break contacts, characterized in that the series-winding windings of the engine-generator pair are connected in opposite directions to each other, and the contacts of each of the reversing switches are connected to the corresponding circuit with the possibility of simultaneously changing the direction of switching on of the excitation windings of the traction motors, the anchor winding and the series winding excitation of the corresponding machine engine-generator pair.

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