RU2467899C1 - Diesel locomotive electric transmission - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to railway transport facilities, particularly, to diesel locomotive electric transmissions. Proposed device consists of traction generator driven by diesel engine and including independent excitation winding and armature. Traction motors are directly connected to traction generator armature, mounted axles engaged with traction motors. Traction generator armature circuit incorporates switching element to respond to control signal generated in the zone of locomotive adhesion limitation and at wheels slippage to inhibit direct connection of motors to generator armature and to allow connection of mounted axles in series with traction motors to generator armature. Electric transmission is provided with control unit to measure motor rpm in response to signals sent by speed transducers connected with motors and to register origination and termination of slippage. Said control unit connects only two slipping mounted axles to traction generator armature by feeding current pulses thereto in turns.

EFFECT: improved traction.

2 cl, 5 dwg

Description

The invention relates to rail vehicles and directly relates to electric transmissions of diesel locomotives.

Known electric transmission of the locomotive [US Pat. No. 2314948 of the Russian Federation. Electric transmission locomotive. / A.I. Ivakhin, BCKossov, Yu.V. Babkov, G.M. Volokhov], consisting of a traction generator that receives mechanical energy from a diesel engine and contains an independent excitation winding and an armature, an excitation system that is connected to an independent excitation winding and provides the formation of the external characteristics of the traction generator, traction motors having a direct electrical connection with the armature of the traction generator, wheel sets mechanically connected to the traction motors and mounted on rails. At the same time, a switching device is installed in the armature circuit of the traction generator, which, by the control signal generated in the zone of restriction on the clutch of the locomotive and when the clutch of the wheelset and rails breaks, ensures that the direct electrical connection of the traction motors with the arm of the traction generator is disconnected and connected to the armature in series with the traction electric motors of wheel pairs through sliding contacts, which forms a circuit for passing the current of the generator along the wheel pairs and rails. Wheel pairs and sliding contacts are electrically isolated from other structural elements of the locomotive.

The disadvantages of this technical solution include the fact that when using more than two driving wheelsets on a diesel locomotive and when the switching device is switched on, the current of the traction generator passes through parallel circuits containing wheel sets and sections of rails. This leads to a significant decrease in the magnitude and density of the current in the zones of contact of the wheels of the locomotive with the rails and, consequently, to a deterioration in the traction qualities of the locomotive in comparison with the biaxial design.

The technical result of the invention is to increase the traction qualities of a multi-axle locomotive by controlling the supply of electric current to the traction generator in the contact areas of the wheelsets with the rails.

To achieve the specified technical result, an electric transmission consisting of a traction generator receiving mechanical energy from a diesel engine and containing an independent excitation winding and an armature, an excitation system connected to an independent excitation winding and providing the formation of an external characteristic of the traction generator, traction motors having a direct electrical connection with the anchor of the traction generator, wheel sets mechanically connected with traction motors and mounted on b, and moreover, a switching device is installed in the armature circuit of the traction generator, which, by the control signal generated in the zone of restriction on the clutch of the diesel locomotive and upon failure of the clutch of the wheel pairs with the rails, disconnects the direct electrical connection of the traction motors to the arm of the traction generator and connects to the armature in series with traction electric motors of wheel pairs through sliding contacts, which forms a circuit for passing the current of the generator along wheel pairs and rails, and wheel pairs and sk sliding contacts are electrically isolated from other structural elements of the locomotive, equipped with a control unit that has the function of measuring the acceleration of rotation of the traction motors by signals taken from the outputs of the speed sensors associated with the electric motors, and records the occurrence and end of the boxing mode of the wheelsets, and the wheelset chains multi-axle locomotives are equipped with their own switches, which according to the signals of the control unit provide a serial connection to the traction armature circuit a generator of only two wheelsets located in locomotive wheelslip mode.

In addition, in the simultaneous boxing mode of more than two wheelsets, the control unit through the switches provides the formation of serial connections of the boxing wheelsets in two with alternating supply of current pulses of the traction generator to each connection, while the duration and frequency of the current pulses are set by the control system according to the results of measurements of rotation accelerations traction electric motors.

The invention is illustrated by drawings.

The electric transmission contains (Fig. 1) a traction generator 1 with an independent excitation winding 2 and an armature 3, receiving mechanical energy from a diesel engine (not shown in Fig. 1), an excitation system 4 connected to an independent excitation winding 2, traction motors 5, 6 , 7, 8, 9, 10, having a direct electrical connection with the armature 3 of the traction generator 1, wheel pairs 11, 12, 13, 14, 15, 16, mechanically coupled (not shown in FIG. 1), respectively, with the traction motors 5, 6, 7, 8, 9, 10 and mounted on the rails 17. To simplify figure 1 also not showing The excitation windings of traction electric motors.

Wheel pairs 11, 12, 13, 14, 15, 16 through the sliding contacts 18, 19, 20, 21, 22, 23 are connected by a switching device 24 to the armature circuit 3 of the traction generator 1 in series with the traction motors 5, 6, 7, 8, 9 and 10. In addition, the locomotive wheelsets are equipped with their own switches 25, 26, 27, 28, 29 and 30, which, according to the signals of the control unit 31, provide individual connection of the wheelsets to the traction generator. The inputs of the control unit 31 are connected to the outputs of the speed sensors 32, 33, 34, 35, 36, 37 associated with electric motors 5, 6, 7, 8, 9, and 10, respectively.

As an example, figure 1 shows a diagram of the electric transmission of a locomotive in direct current with six driving wheelsets and parallel-serial connection of traction motors. In the case of the use of electric transmissions with alternating direct current or alternating current, wheel pairs are likewise included in the armature circuit of the traction generator at the output of the rectifier installation. Differences in the type of connection of traction electric motors and the number of drive wheelsets also do not matter.

Electric transmission operates as follows.

Traction generator 1 (Fig. 1) receives mechanical rotation energy from a diesel engine (not shown in Fig. 1). In this case, the independent excitation winding 2 of the generator is connected to the excitation system 4, which ensures the formation of the external characteristics of the traction generator 1. From the armature 3 of the generator, a supply current is supplied to the traction motors 5, 6, 7, 8, 9, 10, which creates a torque of the electric motors, further transmitted through mechanical connections (traction reducers) respectively to wheel pairs 11, 12, 13, 14, 15, 16. Wheel sets 11, 12, 13, 14, 15, 16 are mounted on rails 17 and form friction pairs with the latter, forming a force traction locomotive F _to . As an example, figure 2 shows a simplified traction characteristic of a locomotive [Osipov S.I. and other Fundamentals of locomotive traction / S.I. Osipov., K. A. Mironov, V. I. Revich. - M .: Transport, 1979. -. 440, S.112-121], which represents the dependence tangent locomotive traction force F _{to the} speed of movement V and irrespective of the power limit comprises portions clutch 1 by the starting current limitation traction generator 2 and limits on diesel power 3. The clutch restriction section 1 is calculated for dry rails, and the inrush current restriction section 2 is based on the condition that less traction is realized than on section 1 to reduce the possibility of wheel pair blocking. In this case, the starting and acceleration of the locomotive is made according to curve 2 with the greatest traction force F _k .

The wetting of the rails, the ingress of oil into the contact of the wheel and the rail, and other factors cause a decrease in the friction coefficient ψ at all speeds of the locomotive V and, consequently, a decrease in the section 1 of the traction characteristic (curve 2 'in FIG. As a result, the clutch breaks down (in Fig. 2, point A), which leads to the mode of boxing of the wheel pairs and a decrease in the traction force F _k . In this case, the front wheel pairs of each trolley are mainly subject to boxing due to their unloading in the traction mode of operation of the locomotive [Theory and design of locomotives: Textbook. for universities railway transp. / Ed. G.S. Mikhalchenko. - M .: Route, 2006. - 584 p., S.190-204]. For example, in figure 1, such wheelsets are pairs 11, 14 when the locomotive moves in one direction and 13, 16 when it moves in the other direction.

It is known [Minov A.K. Improving the traction properties of electric and diesel locomotives with electric transmission. - M .: Transport, 1965. - P.229], that the boxing mode starts when the circumferential acceleration of the wheelset w exceeds 0.45-0.5 m / s ² . To highlight the boxing mode of wheel pairs, the control unit 31 (Fig. 1) makes a differentiation of the signals according to the rotational speeds of the rotors of the traction electric motors f _p 1, f _p 2, f _p 3, f _p 4, f _p 5 and f _p 6 received at the unit control from speed sensors 32, 33, 34, 35, 36, 37, which are connected respectively with electric motors 5, 6, 7, 8, 9, 10. The result of differentiation for each electric motor is the angular acceleration of its rotor

ε _p = T _d df _p / dt,

where T _d - the time constant of differentiation, the value of which determines the necessary duration of the measurement process ε _p .

In the case of allocation for two engines 5, 8 or 7, 10, mechanically connected with the wheelsets 11, 14 or 13, 16, at least one value of ε _p , which in terms of corresponds to a value of w exceeding 0.5 m / s ² , the control unit 31 provides a signal to the switches 25, 28 or 27, 30. The switches connect to the armature circuit 3 of the traction generator 1 wheel pairs 11, 14 when the locomotive moves in one direction or 13.16 when it moves in the other direction through sliding contacts 18, 21 or 20, 23. After that, the control unit 31 provides a signal to the switching device 24, which is open It has a direct electrical connection to the traction electric motors with the anchor of the traction generator. As a result, a chain is formed for passing the current of the generator 1 only along two wheelsets and rails 17 in series with the traction motors, which leads to a significant increase in the coefficient of adhesion ψ of the wheels with rails and, consequently, to an increase in the portion of the limit on the adhesion of the traction characteristic with respect to boxing wheel pairs (figure 2 - curve 1 "). This leads to the cessation of the mode of boxing of the wheelsets, and the traction force F _to is implemented in section 2.

The moment of the end of the boxing is also fixed by the control unit 31 (Fig. 1) by measuring ε _p corresponding to w <0.45 m / s ² , and a signal is sent from the unit 31 to the switching device 24, which forms a direct connection of the traction motors with the armature of the generator 1 In this case, the main part of the generator current will pass along the path of least resistance, bypassing the wheelset chains containing commutators, sliding contacts and wheel contacts with rails. The traction qualities of the locomotive will be determined by the adhesion coefficient ψ close to natural.

When the blocking mode of the front wheel pairs occurs again, the control unit 31 again sends a signal to the switching device 24, which disconnects the direct electrical connection of the traction motors with the anchor of the traction generator. Further, the system operates according to the above algorithm.

Figure 3 shows the dependence of the adhesion coefficient ψ on the sliding speed V _ck (or slip coefficient s) 1 at a fixed locomotive speed V [P. Wigner. Traction and energy indicators of electric locomotives of the 250 series. // Railways of the world. - 1985. - No. 10, S.9-16]. By a similar dependence, the maximum possible traction force changes, determined by the well-known expression F _к = ψG, where G is the coupling weight of the locomotive, and for the wheelset, axial load. The boxing mode occurs at point A and is characterized by an increased sliding speed and a decrease in adhesion coefficient compared to the maximum value ψ _{max 1} . When the generator current is applied to the wheel contacts with the rails, their adhesion coefficient increases to the maximum value ψ _{max 2} (Fig. 3 - curve 2), which causes an increase in the traction force F _k and a decrease in the sliding speed V _c . At point C, the boxing mode ends and the current supply to the wheelset circuit is turned off. A subsequent decrease in traction coefficient can lead to repeated boxing. As a result, the traction force is realized along a closed curve 3 (Fig. 3), without leading to the differential blocking of the wheel pairs.

At point B (FIG. 2), curve 2 or 3 intersects the characteristic portion 1 ′, which determines the exit of the wheel pairs from the boxing zone. Further boxing modes do not occur, and the control unit 31 turns off the switches 25, 28 or 27, 30, translating the power transmission (figure 1) to its original state. In addition, the circuit is returned to its initial state by the load shedding signal of the traction generator (not shown in FIG. 1).

In a simplified embodiment, the operation of the circuit can be carried out without disconnecting the generator current from the circuits of the wheelsets on the plot AB (figure 2), i.e. in the area of possible boxing. Moreover, after registering the moment of the end of the boxing mode for wheel sets, the control unit 31 (Fig. 1) does not send a signal to the switching device 24, which does not lead to the formation of a direct connection of the traction motors with the armature of the generator 1. The transition of the traction characteristic from section 2 to section 3 ( figure 2) usually occurs at speeds of 5-15 km / h. In section 3, the thrust force F _k decreases rapidly, and the speed of the locomotive V increases. When reaching a speed of V> 15 km / h, guaranteeing an exit from the zone of possible boxing, the control unit 31 (Fig. 1) captures the signals f _{p of the} sensors 32, 33, 34, 35, 36, 37, corresponding in terms of the indicated speed, and gives their signals to the switching device 24 and the switches 25, 28 or 27, 30. The switching device 24 forms a direct connection of the traction electric motors with the armature of the generator 1, and the switches 25, 28 or 27, 30 disconnect the wheel pairs 11, 14 or 13 from the generator, 16. Power transmission (figure 1) is restored to its original state.

In the event of a simultaneous boxing mode of more than two wheel pairs, the control unit 31 through the switches 25, 26, 27, 28, 29, 30 provides the formation of two sequential connections of the boxing wheel pairs in two with alternating current pulses of the traction generator 1 for each connection.

If, after entering the front wheel pairs, for example, 11 and 14, in the boxing zone, a boxing mode occurs for at least one of the middle wheel pairs 12 and 15 (Fig. 1), which are also subject to some unloading, then the electric transmission, as an option, works as follows .

The control unit 31 according to the signals f _p 2 and f _p 5 coming from the outputs of the speed sensors 33 and 36 of the traction motors 6 and 9, mechanically connected with the wheel pairs 12, 15, similarly registers the value of the acceleration of rotation ε _p , which in terms of value w exceeding 0.5 m / s ² . In this case, there are four possible cases of registration of the beginning of the boxing mode of wheel sets 12 and 15.

If the blocking of the wheel pairs 12 and 15 occurs during the blocking mode of the wheel pairs 11 and 14, to which the current I _{11, 14} (Fig. 4) of the traction generator is supplied in accordance with the above algorithm, the control unit 31 captures the occurrence time t _A2 the boxing mode of the wheel pairs 12, 15 and sends a signal to the switching device 24. This signal blocks the signal of the end of the boxing mode of the wheel pairs 11, 14, and direct electrical connection of the traction motors with the anchor of the traction generator for consideration of this mode is disabled. At the time t _{C1 of the} end of the boxing mode of the wheelsets 11, 14, which is determined by the acceleration ε _p corresponding to these wheelsets w <0.45 m / s ² , signals are sent from the unit 31 to turn on the switches 26, 29, and through the time interval Δt necessary to ensure the continuity of the current of the traction generator, the signals are sent to turn off the switches 25, 28. In this case, the chain of wheel pairs 12, 15 containing the sliding contacts 19, 22 (Fig. 1) and the rails 17 is connected to the armature 3 of the traction generator 1, and wheel sets 11.14 are disconnected from it. As a result, the current of the generator I _{12, 15} (Fig. 4) passes through two wheelsets 12, 15 and rails 17, which leads to a significant increase in their adhesion coefficient ψ and the termination of the boxing mode. Due to the increase in the coefficient of adhesion of wheel pairs with rails during the passage of current is much higher than calculated [Pat. No. 2314948 of the Russian Federation. Electric transmission of the locomotive / A.I. Ivakhin, BCKossov, Yu.V. Babkov, G.M. Volokhov], and also because of the rather high inertia of the traction drive of the wheelsets, the process of their exit from the boxing mode (Fig. 3 is a curve AC) occurs much faster than the transition to it (curve SA). In Fig.4, 5, this is reflected in the time t _A and t _C corresponding to points A of the beginning and C of the end of the boxing of the wheelsets (Fig.3). Therefore, despite the fact that by the time moment t _C1 the sliding speed V _{ck of the} wheel pairs 12, 15 will be slightly higher than at point A (Fig. 3), the end of the boxing mode of the wheel pairs 12, 15 will occur earlier than the subsequent mode Boxing wheel sets 11, 14.

At time t _C2, the control unit 31 detects the end of the wheel pairing mode 12, 15 according to the signals f _p 2, f _p 5 of the sensors 33, 36 (Fig. 1) and when the occurrence of the subsequent blocking mode of the wheel pairs 11, 14 is detected at the time f _A1 (figure 4) performs the reverse switching of the switches 26, 29 to the switches 25, 28. Similar switching processes occur to point B (figure 2), which is the boundary of the exit of the wheelsets from the boxing zone, and the signals for switching on and off switches are formed by the control unit 3 1 when fixing the end of the boxing mode of some and the occurrence of boxing of other wheelsets. Thus, for each connection containing two wheelsets, the current pulses of the traction generator 1 are alternately supplied, the duration and frequency of which is set by the control unit 31 according to the measurement results of the acceleration of rotation of the traction motors. At point B (figure 2), the power transmission is restored to its initial state by one of the methods similar to those previously considered for the case of boxing of two front wheelsets.

If the moment t ^I _{A2 of the} occurrence of blocking of the wheelsets 12 and 15 coincides with the time t _{C1 of the} end of the mode of blocking of the wheelsets 11 and 14 (Fig. 4), then the control unit 31 fixes these two processes at the same time, and the system operates as described in the previous case the algorithm.

If the moment t ^II _{A2 of the} occurrence of blocking of the wheel pairs 12 and 15 coincides with the moment t _{A1 of the} beginning of the next mode of blocking of the wheel pairs 11 and 14 (Fig. 4), the control unit 31 first connects the wheel pairs 11, 14 to the armature 3 of the generator 1 by feeding signal to the switching device 24, which disables the direct electrical connection of the traction motors with the armature of the traction generator. This is due to the lack of registration by the unit 31 of the end of the boxing mode of the wheel pairs 11, 14, which at the beginning of the considered mode is a necessary condition for connecting the wheel pairs 12, 15. The generator current I _{11, 14} passes through the wheel pairs _{11, 14} , leading to a significant increase in them the friction coefficient ψ and the end of the boxing mode at time t _C1 , which ensures the connection of the wheel pairs 12, 15 to the armature circuit of the traction generator in the sequence above. Further, the system operates according to the algorithm considered in the first case.

If the blocking of the wheel pairs 12 and 15 occurs after the end of the blocking mode of the wheel pairs 11, 14 (Fig. 5), the control unit 31 captures the moment t _{A2 of the} occurrence of the blocking mode of the wheel pairs 12, 15 and sends a signal to the switches 26, 29. The switches connect to the chain of the armature 3 of the traction generator 1 wheel pairs 12, 15 through the sliding contacts 19, 22. After that, the control unit 31 sends a signal to the switching device 24, which disconnects the direct electrical connection of the traction motors with the armature of the traction generator. As a result, a chain is formed for the current of the generator I _{12, 15} to pass through two wheelsets 12, 15 and rails 17 in series with the traction motors, which similarly leads to a significant increase in the coefficient of adhesion ψ of the wheels with rails and the end of the blocking mode at time t _C2 . In the event of a repeated blocking mode of wheel sets 11, 14 (time t ' _A1 ) before the time t _C2, the control unit 31 registers the occurrence of the mode and, upon reaching the time t _C2, gives signals to switch on the switches 25, 28. After a period of time Δt required to ensure the continuity of the current of the traction generator, the signals are sent to turn off the switches 26, 29. In this case, the chain of wheel pairs 11, 14 is connected to the armature 3 of the traction generator 1, and the wheel pairs 12, 15 are disconnected from it. Further, the system operates according to the above algorithm.

The entire wheel load is concentrated on the rear wheelsets [Theory and design of locomotives: Textbook. for universities railway transp. / Ed. G.S. Mikhalchenko. - M .: Route, 2006. - 584 p., S.192]. Therefore, their boxing mode is unlikely. But in this case, the implementation of the alternate supply of current pulses of the traction generator to the connections of the wheelsets does not have fundamental differences.

The technical and economic efficiency of the invention lies in the fact that the electric transmission of a multi-axle locomotive contains a control unit, which in the boxing mode provides control of the supply of electric current to the traction generator to the wheelsets. At the same time, only two wheel sets connected in series through rails are connected to the generator at the same time, which allows to realize the greatest values and current densities in the zones of contact between the wheels of the locomotive and the rails and, therefore, increase their adhesion coefficient and traction qualities of the locomotive.

Claims (2)

1. Electric transmission of a diesel locomotive, consisting of a traction generator that receives mechanical energy from a diesel engine and containing an independent excitation winding and an armature, an excitation system that is connected to an independent excitation winding and provides the formation of an external characteristic of the traction generator, traction motors having a direct electrical connection to the armature traction generator, wheel sets mechanically connected with traction motors and mounted on rails, while in the chain of traction armature of the generator, a switching device is installed, which, according to the control signal generated in the zone of restriction on the adhesion of the locomotive and when the wheelset and rails are disengaged, ensures that the direct electrical connection of the traction motors with the arm of the traction generator is disconnected and connected to the armature in series with the traction motors of the wheel pairs through sliding contacts that forms a circuit for passing the generator current through the wheel pairs and rails, and the wheel pairs and sliding contacts are electrically isolation from other structural elements of the diesel locomotive, characterized in that it is equipped with a control unit, which has the function of measuring the acceleration of rotation of the traction electric motors according to the signals taken from the outputs of the speed sensors associated with the electric motors, and records the occurrence and end of the boxing mode of the wheelsets, and the chains wheelsets of a multi-axle locomotive are equipped with their own switches, which, according to the signals of the control unit, provide a serial connection to the traction generator's armature circuit torus of only two wheelsets in boxing mode. 2. The electric transmission according to claim 1, characterized in that in the simultaneous boxing mode of more than two wheelsets, the control unit through the switches provides the formation of serial connections of the boxing wheelsets in two with alternating supply of current pulses of the traction generator to each connection, the duration and frequency current pulses are set by the control unit according to the results of measuring the acceleration of rotation of the traction motors.

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