CN116867665A

CN116867665A - Rail vehicle comprising a plurality of current collectors and method for operating a rail vehicle

Info

Publication number: CN116867665A
Application number: CN202280015613.5A
Authority: CN
Inventors: A·卡纳尼
Original assignee: Bombardier Transportation GmbH
Current assignee: Alstom Transportation Germany GmbH
Priority date: 2021-02-17
Filing date: 2022-02-16
Publication date: 2023-10-10
Also published as: GB202102237D0; GB2603906A; WO2022175336A1; EP4259469A1

Abstract

The invention relates to a method of operating a rail vehicle (1), the rail vehicle (1) comprising: -a plurality of current collectors (3), each current collector (3) electrically connecting the rail vehicle (1) with an energy supply network (6); -a plurality of converters including a first converter (11 a) and a second converter (11 b), each converter (11) being respectively assigned to a designated one (3) of the plurality of collectors (3) and converting a direct current at an input side of the converter (11) into an alternating current at an output side of the converter (11) by repeatedly switching on and off a converter switch (25) according to phase information about a phase position of an alternating voltage and/or a phase current at the output side of the converter (11); -an alternating current line (15) electrically connecting the output sides of the converters (11), wherein when the rail vehicle (1) passes a segmentation point of the energy supply network (6), an interruption of the energy supply from the energy supply network (6) through a designated current collector (3) of the first converter (11 a) to the input side of the first converter (11 a) occurs, a) the interruption is detected; b) Stopping converting the direct current at the input side of the first converter (11 a) into alternating current at the output side of the first converter (11 a); c) Continuing to process phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter (11 a) during the interrupted period of time; d) -detecting a return of the energy supply network (6) to the input side of the first converter (11 a); and e) the processing result of continuing to process the phase information during the interrupted period is used to restart the conversion of the direct current at the input side of the first converter (11 a) into an alternating current at the output side of the first converter (11 a).

Description

Rail vehicle comprising a plurality of current collectors and method for operating a rail vehicle

Technical Field

The present invention relates to a rail vehicle and a method of operating a rail vehicle. The rail vehicle comprises a plurality of current collectors, wherein each current collector electrically connects the rail vehicle with the energy supply network during operation.

Background

However, during operation of the rail vehicle, in particular when the rail vehicle is travelling on a track, there may be periods of time when the energy supply network does not supply electrical energy via the at least one current collector: an energy supply network consisting of a power supply line in the form of an overhead power supply line or a live rail (commonly referred to as a third rail) includes segmented points that electrically isolate successive segments of the power supply line from each other. At the segmentation point, there is a gap between consecutive segments. This means that there is no electrical connection between successive segments. Thus, when the rail vehicle passes the staging point, the current collector (e.g., a pantograph for contacting an overhead power line or a contact block for contacting a third rail) may lose electrical connection with the energy supply network for a short period of time. Since the rail vehicle is composed of a plurality of current collectors, the rail vehicle can still be supplied with electric energy in this short time.

There are different kinds of devices in rail vehicles that require electrical energy to operate. One device belongs to traction systems, such as traction motors, current transformers, electrical connections thereof, and electrical components electrically connected to these devices. Another device is called an auxiliary device, belonging to the auxiliary system of the railway vehicle. The auxiliary device supports the operation of the rail vehicle but does not belong to the traction system. For example, cooling means for cooling the current transformer and traction motor, and control means for controlling the operation of the traction system means. At least some of the auxiliary devices are necessary for propulsion and braking of the rail vehicle. For example, if the traction converter control device that provides power to at least one traction motor ceases to operate, the traction converter can no longer provide power to the traction motor, and can no longer operate in the dynamic braking mode.

The cooling device for cooling the traction system current converter or the traction motor may not stop propelling immediately, but after a period of time. Still other devices, such as electric lights and heating, may provide a comfortable environment for passengers and may also be used to load and unload cargo.

Although the invention is not limited in this regard, it is particularly concerned with providing electrical power to auxiliary devices.

Typically, electrical devices within a rail vehicle are powered by alternating current generated by a current converter (simply "converter"). The ac power line to the electrical device is connected to the "output side" or "ac power side" of the converter. The "input side" or "dc side" of the converter is connected to a dc circuit, commonly referred to as an "intermediate circuit" or "dc bus. If a Direct Current (DC) energy supply network is present on the railway on which the rail vehicle is travelling, electrical energy is typically supplied from the supply network to the input side of the current converter through one of the current collectors and the inductance of the DC circuit. If an Alternating Current (AC) power supply network is present on the railway, power is typically passed from the supply network through one of the current collectors, through the transformer to the line converter and to the dc circuit. The line converter rectifies the alternating current of the secondary side of the transformer into direct current of the direct current circuit.

In particular, when supplying energy to the auxiliary device, a plurality of current converters, i.e. auxiliary system current converters, may be provided, wherein each auxiliary system current converter converts the direct current of a direct current circuit into an alternating current at its output side. Each direct current circuit is connected to a respective current collector of the rail vehicle, i.e. the energy supply of each direct current circuit by the energy supply network is dependent on the electrical connection of the respective current collector to the energy supply network. When one of the current collectors reaches the segmentation point, its electrical connection to the energy supply network will be interrupted, while the electrical connection of at least one of the plurality of current collectors of the rail vehicle to the energy supply network will remain unchanged. However, at least one of the plurality of current collectors will also reach the segmentation point. In order to be able to supply the auxiliary device continuously with energy, an alternating current circuit is present on the rail vehicle, to which all or more output sides of the auxiliary system current collector are connected. The auxiliary device can be supplied with electrical energy as long as at least one auxiliary system collector feeds alternating current into the alternating current line, although the supply power may drop significantly when one of the collectors passes the segmentation point.

In general, a current converter converts a direct current into an alternating current by repeatedly turning on and off a converter switch. For example, in a three-phase dc-ac converter, there are at least six switches, typically semiconductor switches, such as IGBTs (insulated gate bipolar transistors). Typically, there are at least two switches per phase. There is typically a junction point on the output side (ac side) of the converter between the two switches of the phase. However, there may be more switches per phase, especially when multiple switches are arranged in parallel with each other to increase the maximum allowable current.

After the electrical connection is established between the current collector passing through the segmentation point and the line segment following the segmentation point, the energy supply network re-supplies energy to the designated current transformer through the current collector. However, when the different current converters are connected on their output side to the ac power line, an in-phase ac power must be generated, i.e. a phase shift of the ac power must be avoided during most of the operating time. The phase shift can only occur in a short time. There are two schemes that can meet the requirement that the ac current is in phase when the current transformer is re-supplied with energy through the designated collector after the segmentation point.

According to a first variant, the input sides of the different current converters can be connected to each other via electrical lines in order to supply the current converters with electrical energy from different current collectors. Thus, the current converter may continue to generate alternating current at its output side as the designated current collector passes the segment point. However, the electrical wiring on the input side of the current converter greatly increases the manufacturing time and effort of the rail vehicle.

According to a second variant, the converter control device of the current converter can control the converter switch immediately after the energy supply to the input side of the current converter via the assigned collector has been reestablished in synchronization with the other current converter. However, this requires a certain time, and thus the time gap for suspending the generation of the alternating current is longer than the time period for which the electrical connection to the energy supply network through the designated current collector is interrupted.

Disclosure of Invention

The object of the present invention is to provide a solution for a method of operating a rail vehicle in the above-mentioned situation, as well as a solution for a rail vehicle with the above-mentioned features, which provides a small time gap for suspending the generation of alternating current at the segmentation point and requires little construction effort. Another object of the invention is to provide a corresponding railway vehicle.

For a method and a rail vehicle having the above-mentioned features, it is proposed that phase information about the ac voltage and/or the phase position of the ac current at the output side of the current converter is processed continuously during a period in which the energy supply network supplies energy to the input side of the current converter via a specified collector. Thus, no electrical lines are required to connect the input sides of the different collectors, and immediately after the energy supply network resumes the energy supply to the input side of the current converter through the designated collector, an alternating current can be generated at the output side of the current converter which is synchronized with the other alternating current fed into the alternating current line.

The following are specifically proposed:

a method of operating a rail vehicle, the rail vehicle comprising:

-a plurality of current collectors, each current collector electrically connecting the rail vehicle with an energy supply network;

-a plurality of converters, including a first converter and a second converter, each converter being respectively assigned to a designated one of the collectors and converting a direct current at an input side of the converter into an alternating current at an output side of the converter by repeatedly switching on and off converter switches according to phase information about a phase position of an alternating voltage and/or a phase current at the output side of the converter;

An alternating current line electrically connecting the output side of the converter,

wherein when the rail vehicle passes a segmentation point of the energy supply network, an interruption of the energy supply from the energy supply network to the input side of the first converter via a designated collector of the first converter is caused,

a) Detecting the interrupt;

b) Stopping converting the direct current at the input side of the first converter into alternating current at the output side of the first converter;

c) Continuing to process phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter during the interrupted period of time;

d) Detecting a return of the energy supply network to the energy supply of the input side of the first converter; and

e) The processing result of continuing to process the phase information during the interrupted period is used to restart converting the direct current at the input side of the first converter into alternating current at the output side of the first converter.

Furthermore, a rail vehicle is proposed, comprising:

-a plurality of current collectors, each current collector (e.g. a pantograph or a contact block) being adapted to electrically connect the rail vehicle with an energy supply network;

-a plurality of converters, including a first converter and a second converter, each converter being respectively assigned to a designated one of the collectors and being adapted to convert a direct current at an input side of the converter into an alternating current at an output side of the converter by repeatedly switching on and off converter switches according to phase information about a phase position of an alternating voltage and/or a phase current at the output side of the converter;

-an alternating current line adapted to electrically connect the output side of the converter;

-one or more supply presence sensors adapted to generate a sensor signal indicating whether there is a supply of electrical energy from the energy supply network to the input side of the first converter through a designated current collector of the first converter;

first converter control means adapted to control the operation of said first converter,

wherein when the rail vehicle passes a segmentation point of the energy supply network, an interruption of the energy supply from the energy supply network to the input side of the first converter through a designated current collector of the first converter is caused, the rail vehicle being adapted to:

a) Detecting the interruption from a sensor signal of the supply presence sensor;

d) Detecting a return of the energy supply network to the energy supply of the input side of the first converter from the sensor signal of the supply presence sensor;

e) And restarting to convert the direct current at the input side of the first converter into alternating current at the output side of the first converter by using a processing result of continuing to process the phase information in the interrupted time period.

Embodiments of the method and rail vehicle will be described below. For each embodiment of the method there is a corresponding railway vehicle embodiment and vice versa.

Each of the plurality of converters is electrically connected or capable of being electrically connected (e.g., by closing a switch) to a designated current collector.

There may be more than two current converters with their output sides connected to the ac line. For example, a train may include three or more current collectors, where each current collector is electrically connected or connectable (e.g., by closing a switch) to the input side of one current converter, and the output side of these current converters is electrically connected or connectable (e.g., by closing a switch) to an alternating current line that may extend from the current converter closest to the front of the train to the current converter closest to the rear of the train.

The phase position (commonly referred to as "phase") of the ac voltage and/or ac current at the output side of the converter includes time information that the ac voltage and/or ac current reaches a maximum, minimum or zero value. For example, in the case of three-phase currents, there is typically a 120 ° phase shift between each pair of phases, as is the corresponding ac voltage. According to the basic knowledge of the skilled person, there is also a phase shift between the alternating current and the alternating voltage of each phase, which phase shift depends on the inductances and capacitances involved. However, it is sufficient to control the converter switches so as to generate an alternating current in phase with the alternating current of the other converters at the output side of the converter, as long as the phase position of the alternating voltage or the alternating current at the output side of the converter is known.

There are at least two methods how to continue to process phase information about the phase position of the ac voltage and/or ac current at the output side of the converter during the period of interruption.

According to a first method, the ac voltage and/or the ac current at the output side of the converter is measured as a function of time, i.e. the ac voltage and/or the ac current are repeatedly measured and the measurement is continued for an interrupted period of time. Corresponding sensors for measuring at least one phase voltage of an alternating voltage and/or a phase current of an alternating current are well known in the art, and the converter control means typically process the phase information in the received sensor signals of such sensors. For example, two ac sensors are provided on the output side of the converter, each sensor being arranged and adapted to measure the ac current on one of the three phases of the ac line. In particular, the phase current of the third phase line of the ac line can be calculated on the assumption that the phase difference between each pair of phase lines is 120 ° by the current through the three phase lines. Furthermore, a single voltage sensor may be used to measure the voltage between two of the three phase lines. However, the present invention is not limited to the specific example of two current sensors and one voltage sensor on the output side of the converter. For example, there may be three current sensors and/or two voltage sensors.

In any case, the sensor on the output side of the converter is preferably arranged anywhere outside the line switch in the ac line (see below) to measure the voltage and/or current of the ac line. Thus, the sensor can continuously provide a sensor signal even when the line switch is turned off.

For example, the sensor signal is processed by a control device adapted to control the first converter, the control device being controlled in dependence of the sensor signal. The result of the control is a switching pattern of the converter switches (i.e. a switching sequence of the converter switches over a period of time). In particular, the process performed by the control means for controlling the switching of the converter switches may be performed before the designated collector reaches the segmentation point and may continue to be performed for an interrupted period of time. It is noted that the length of the time period of the interruption is not necessarily equivalent to the length of the time gap between the supply of energy from the energy supply network to the input side of the first converter before the designated current collector reaches the segmentation point and the reestablishment of the supply of energy after the segmentation point. In other words, the converter control device does not have to continue to process the sensor signal during the entire time interval in which no energy is supplied to the input side of the converter. For example, the converter control device only has to continue processing the sensor signal shortly before the end of the time interval. The minimum length of the time gap can be known to the converter control means so that the converter control means can start the continued processing as soon as possible. However, the processing of the sensor signal preferably continues throughout the time interval, i.e. the processing of the sensor signal and the processing of the phase information is not interrupted at a certain time. In any case, the processing of the phase information may be such that the switching pattern is calculated during the time period of the interruption or during the whole time interval. The converter control device may output a corresponding control signal that can obtain the switching pattern to the converter switch, so that the converter switch is actually switched, or may not output a control signal to the converter switch during the interruption period.

According to the second method, the processing of the phase information during the period of interruption is independent of the sensor signal or may not be entirely dependent on the sensor signal. This has the advantage that the required processing power is lower and that the phase information is not dependent on the ac current at the output side of the first converter during the period of interruption. Although the output side of the first converter may be connected to the ac line during the period of interruption, the ac current in the ac line in the vicinity of the first converter may not be suitable for acquiring phase information. According to a second method, it is assumed that the phase of the alternating voltage and/or the alternating current in the alternating current line does not change at the beginning of the interruption of the energy supply from the energy supply network to the input side of the first converter at the segmentation point and within the time interval of the interruption. For example, the processing of the phase information during the period of interruption may comprise continuously or repeatedly receiving a time signal (e.g. an internal clock from the converter control means) and calculating the phase position/phase state at least when it is detected that the energy supply from the energy supply network to the input side of the first converter has returned. Alternatively, the phase position/phase may be calculated continuously or repeatedly from the time signal.

In particular, the period of interruption (i.e. the interruption time interval) may end when the designated current collector of the first converter has been electrically connected to the energy supply network after passing the segmentation point, but the operation of the first converter has not yet been restarted. In any case, the period of interruption preferably starts when there is no electrical connection between the designated current collector of the first converter and the energy supply network, for example no electrical contact between the designated current collector and the overhead power line or the third rail. Furthermore, when there is no electrical connection between the designated collector of the first converter and the energy supply network, it is preferable to continue to process phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter.

The alternating current line may extend in or along the direction of travel through the rail vehicle at least from the location of the first converter to the location of the second converter. Typically, the first and second transducers are located in different parts of the rail vehicle, such as different cars of a train.

The supply presence sensor is in particular located at the input side of the first converter, anywhere within the circuit between the first converter and its assigned current collector. Typically, the first sensor is located in the electrical connection between the designated collector and the main transformer (ac supply network) or main inductance (dc supply network), and the second sensor is located in the input-side dc circuit. The first sensor may measure the current voltage at the electrical connection and the second sensor may measure the voltage of the dc circuit. If there is more than one supply present sensor, a sensor signal from one of the sensors after reaching the segmentation point may indicate that the energy supply is not present, while a sensor signal from another of the sensors may indicate that the energy supply is returned (i.e., present). For example, the sensor signal of the second sensor may be used to detect the presence or absence, because this may reduce the delay in stopping the alternating current generated by the first converter, thereby shortening the period of time during which no alternating current is generated. On the other hand, the energy supply returned from the energy supply network may preferably be indicated by the sensor signal of the first sensor, since the sensor is closer to the collector, which sensor signal may be used by the converter control means to detect the return.

However, according to a particularly reliable solution, it is possible to use at least the signal of the voltage sensor in the direct current circuit (i.e. the aforementioned embodiment of the second sensor) to detect the presence of the supply of electrical energy from the energy supply network to the input side of the first converter through the assigned collector of the first converter when the segmentation point is reached and to detect the return of the supply of electrical energy after the segmentation point. Shortly after reaching the segmentation point, the voltage in the dc circuit will drop, which can be detected if the condition that the voltage drops by a predetermined voltage difference and/or to a predetermined voltage value is fulfilled. When the power supply returns, a return of the voltage may be detected if a condition that the voltage increases by a predetermined voltage difference and/or reaches a predetermined voltage value is met. In all these cases, for example, the converter control of the first converter can detect whether the energy supply on the input side of the first converter is interrupted by evaluating the sensor signal of the supply presence sensor.

While the rail vehicle and the method of operating the rail vehicle have been described and will be described with particular reference to a first converter, the same description may be applied to a second converter or any other converter that has been or may be connected to an ac power line. In particular, the collector assigned to the second converter or any other converter will reach the segmentation point later or earlier than the collector assigned to the first converter. Thus, all the solutions and embodiments described for the first converter are also applicable to the second converter or any other converter.

In particular, the rail vehicle comprises a line switch which can be controlled (e.g. by a control device of the first converter or another control device of the rail vehicle) for opening and closing an electrical connection between the output side of the first converter and the ac line. Thus, the line switch has two states, open and closed. In the disconnected state, the output side of the first converter is disconnected from the output side of the second converter and from the output side of the other converters which are connected or connectable to the ac line.

When an interruption is detected, the line switch is preferably kept in a closed state to maintain an electrical connection between the output side of the first converter and the ac line. The rail vehicle can be adjusted accordingly. This embodiment has at least the following advantages. The alternating current generated by the other converter connected to the alternating current line may be used to transfer electrical energy to the first converter, which may rectify the alternating current to transfer electrical energy to the direct current circuit on its input side. Such power may be used for different purposes, such as maintaining the voltage of the dc circuit at a higher level, and/or providing power to any other device connected to the dc circuit.

However, in some cases, the line switch may be opened in the event that the energy supply network does not supply energy to the input side of the first converter via the designated current collector. For example, if there is a large ac current in the ac line to the first converter (e.g., the current exceeds a predetermined threshold), the line switch may be opened.

In particular, the converter may be an auxiliary converter for supplying auxiliary devices of the rail vehicle with electrical energy via an alternating current line. As mentioned above, auxiliary devices are used to support the operation of the rail vehicle, but do not belong to the traction system of the rail vehicle, although they may support the operation of the traction system device.

The control means of the first converter may use (or be adapted to use) the processing result of the processing of the phase information to synchronize the repeated switching on and off of the first converter switch with the phase position of the ac voltage and/or the ac current at the output side of the first converter. In this way the operation of the different converters connected to the ac line at the output side can be optimized.

For example, as mentioned above, the rail vehicle may comprise at least one ac line sensor for sensing the ac voltage and/or the ac current at the output side of the first converter, wherein phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter may be obtained from the sensor signal of the at least one ac line sensor. The rail vehicle can be adjusted accordingly.

When the energy supply network returns through the designated collector to the energy supply of the input side of the first converter, the generation of alternating current of the first converter can be restarted. However, due to inductance and capacitance, the ac current fed into the ac line may not be immediately in phase with the ac current produced by the second converter or other converter connected to the ac line. Thus, in a period of time after restarting converting the direct current at the input side of the first converter into the alternating current at the output side of the first converter, the repeated switching on and off of the first converter switch is preferably controlled irrespective of the phase information about the phase position of the alternating voltage and/or the alternating current at the output side of the first converter. In particular, the control device of the first converter can be adjusted accordingly.

There are various ways in which information about the phase position can be ignored. One approach is not to continue processing the sensor signal of the sensor measuring the ac voltage and/or the ac current in the ac line, since the sensor signal represents the ac current generated by the influence of the inductance and the capacitance, or the sensor signal is at least influenced by the inductance and the capacitance. In contrast, the converter control device may be adjusted accordingly in accordance with the phase information process before restarting in such a period of time after restarting the operation of the first converter, thereby achieving control of the converter switch. Another approach is to filter repeatedly and/or continuously received phase information, which may be generated by a sensor measuring the ac voltage and/or ac current in the ac line. For example, a filter may be used to "sliding average" filter the received phase information, i.e., consider the most recently received phase information and the phase information received over a set length of time period in the past at each point in time.

Drawings

Examples and embodiments of the present invention will be described with reference to the accompanying drawings. The figure shows:

fig. 1 schematically shows a rail vehicle traveling on an electrified line having an overhead power line thereon, including a staging point, the rail vehicle being approaching the staging point;

fig. 2 is an arrangement after a short time of fig. 1, when the first current collector of the rail vehicle has reached the segmentation point;

fig. 3 is an arrangement after a short time in fig. 2, where the first current collector of the rail vehicle has passed the segmentation point and is in contact with another segment of the overhead power supply line;

FIG. 4 is an exemplary schematic diagram of the electrical devices and circuits of the rail vehicle of FIGS. 1-3 in the situation of FIG. 1;

FIG. 5 is an exemplary schematic diagram of the electrical devices and circuits of the rail vehicle of FIGS. 1-3 in the situation of FIG. 2;

FIG. 6 is an exemplary schematic diagram of the electrical devices and circuits of the rail vehicle of FIGS. 1-3 in the situation of FIG. 3;

FIG. 7 is a detail of an embodiment of the circuit and one of the converters shown in FIGS. 4-6;

FIG. 8 shows a flow chart illustrating the operation of a rail vehicle in passing through a staging point of an energy-supply network section; and

fig. 9 is a graph of the ac current produced by the current converter as a function of time over a period of time when the rail vehicle passes through a segment point of the energy supply network segment.

Detailed Description

Fig. 1 shows a rail vehicle 1 running on a track of a railway 5. The rail vehicle 1 comprises two current collectors 3a, 3b which are in electrical contact with overhead line sections 6a, 6b of an energy supply network 6. In the situation shown in fig. 1 (and fig. 4, which will be explained later), both current collectors 3a and 3b are in electrical contact with a first section 6a of the energy supply network 6. The energy supply network 6 thus supplies energy to the rail vehicle 1 via the two current collectors 3a and 3 b.

In the case shown in fig. 2 (and fig. 5, which will be explained later), the first current collector 3a reaches the segmentation point 7 of the energy supply network. At the segmentation point 7, a gap exists between the first overhead line segment 6a and the second overhead line segment 6 b. Thus, the electrical connection of the first current collector 3a to the energy supply network 6 is broken, and the energy supply network 6 supplies energy to the rail vehicle 1 only via the second current collector 3b, possibly also via other current collectors not shown in the figures.

In the situation shown in fig. 3 (and fig. 6, which will be explained later), the first current collector 3a has passed the segmentation point 7 of the energy supply network and is now in electrical contact with the second overhead line segment 6 b. The second current collector 3b remains in electrical contact with the first section 6a of the energy supply network 6. The energy supply network 6 thus supplies energy to the rail vehicle 1 via the two current collectors 3a and 3 b.

The energy supply network 6 may be a Direct Current (DC) network or an Alternating Current (AC) network. Furthermore, the energy supply network may not comprise an overhead power supply line, but for example a third rail. With reference to fig. 4 to 6, an example of operation of the railway vehicle 1 shown in fig. 1 to 3 will be described.

As shown in fig. 4 to 6, the rail vehicle 1 may comprise two current converters 11a, 11b. The input side of each current converter 11a, 11b is connected to a dc circuit 14a, 14b, and the output side is connected to an ac line 15 via an ac line switch 12a, 12 b. As shown in fig. 4-6, each dc circuit 14a, 14b may have a capacitance therein. An electrical load (not shown) is connected to the ac power line 15. The ac line switches (abbreviated as line switches) 12a, 12b may be controlled by control means, which may be current control means 16a, 16b controlling the operation of a respective one of the current converters 11a, 11b, or any other control means (not shown) controlling at least one switch and/or device in the arrangement shown. Fig. 4 shows the converter control device 16b of the second current converter 11b, but fig. 5 and 6 are not shown.

The current collectors 3a and 3b are electrically connected to one of the dc circuits 14a and 14b via main inductances 13a and 13b, respectively. If the energy supply network is an ac network, the main inductances 13a and 13b are replaced by a main transformer for converting the voltage of the energy supply network into a lower voltage and a line converter for rectifying the ac current in the collectors 3a and 3b into dc current.

In particular, the current converter 11a, 11b may be an auxiliary system current converter for providing ac power to an auxiliary device (not shown) via an ac line 15. Alternatively, the current converters 11a and 11b may be traction converters for providing traction energy to at least one electric traction motor (not shown).

The converter control device 16a of the first current converter 11a is connected to the dc circuit sensor 17a and to the ac line sensor 18 a. The dc circuit sensor 17a is adapted to repeatedly or continuously measure the voltage in the dc circuit 14 a. The ac line sensor 18a is adapted to measure the ac voltage and/or the ac current in the ac line, and the ac line sensor 18a is located at a position outside the ac line switch 12a as seen from the first current converter 11 a. In particular, the ac power line may be a three-phase ac power line, as shown by the three diagonal lines. During operation of the rail vehicle 1, the converter control device 16a repeatedly or continuously receives sensor signals of the direct current circuit sensor 17a and the alternating current line sensor 18 a. The converter control device 16a processes the sensor signal and controls the first current converter 11a based on the sensor signal.

In the case shown in fig. 1 and 4, electric power is supplied from the power supply network to the current converters 11a and 11b through the collectors 3a and 3b, and the current converters 11a and 11b convert the direct current on the input side (the side of the corresponding direct current circuits 14a and 14 b) thereof into the alternating current on the output side (the side of the alternating current line 15). This switching operation belongs to the inversion operation. Except for the case shown in fig. 4, the line switches 12a and 12b are closed, causing an alternating current to flow through the alternating current line 15 to the device connected to the alternating current line 15.

In the case shown in fig. 2 and 5, electrical energy is continuously supplied from the energy supply network through the second current collector 3b to the second current converter 11b, which converts the direct current on its input side into an alternating current on its output side. When the first current collector 3a reaches the segmentation point 7 and loses electrical contact with the energy supply network, the voltage in the first direct current circuit 14a decreases, while the first current converter 11a continues to convert the direct current in the first direct current circuit 14a into an alternating current which is fed into the alternating current line 15. For example, when the dc circuit sensor 17a senses a predetermined voltage or voltage drop in the first dc circuit 14a and the corresponding sensor signal reaches the first converter control device 16a, the first converter control device 16a stops the current inversion operation. Then, electric energy is supplied from the energy supply network only through the second current collector 3b to the second current converter 11b, and the second current converter 11b generates an alternating current fed into the alternating current line 15. In particular in the converter configuration shown in fig. 7, the first current converter 11a comprises diodes, so that the alternating current in the alternating current line 15 is rectified and the direct current is input to the first direct current circuit 14a. The corresponding energy flow is indicated by arrows in fig. 5. Therefore, the capacitor of the first dc circuit 14a maintains a charged state and can maintain a certain voltage level.

In the situation shown in fig. 3 and 6, the first current collector 3a has passed the segmentation point 7 and is in electrical contact with the second overhead line segment 6b of the energy supply network 6. The first current converter control means 16a senses whether the power supply of the first direct current circuit 14a is returned or not by the sensor signal of the direct current circuit sensor 17a, because the power supply through the first current collector 3a and the main inductance 13a increases the voltage of the first direct current circuit 14 a. For example, when a predetermined voltage or a voltage rise of the first direct current circuit 14a is sensed, the first current converter control means 16a starts to control the switching action of the converter switch of the first current converter 11 a.

After the operation of converting the direct current into the alternating current is stopped (as in the case of fig. 2 and 5) and before the operation is restarted (as in the case of fig. 3 and 6), the phase information on the phase position of the alternating voltage and/or the alternating current on the output side of the first converter is continued to be processed. Therefore, the first current converter control device 16a is ready to control the switching operation of the converter switch of the first current converter 11a so that the alternating current generated by it is in phase with the alternating current in the alternating current line 15 or so that the alternating voltage at the output side thereof is in phase with the alternating voltage in the alternating voltage line 15, before restarting the inversion operation.

The first converter control device 16a may acquire phase information during the interrupted period from the sensor signal of the alternating current line sensor 18 a. During the period of interruption, the first line switch 12a remains closed. Another way to obtain phase information is to infer a periodic variation of the ac current and/or the ac voltage in the ac line 15 over a period of time, which is particularly suitable in case an ac current in the ac line 15 is too high resulting in the opening of the first line switch 12 a. This means that the sensor signals of the ac line sensor 18a can be stored in a data memory of the first converter control device 16a, and the stored data can be accessed if necessary for an inference.

The arrangement shown in fig. 7 shows details of one particular embodiment. The dc power supply 20 on the left side of the figure may represent at least the energy supply network and the designated current collector of the first current converter. The dc circuit 21 is connected to the dc power supply 20. The dc circuit 21 includes an inductor 23, a switchable resistor 24, and a switch 22 for disconnecting the dc circuit 21 from the dc power supply 20.

The converter circuit 30 is connected to the dc circuit 21. The converter circuit 30 comprises a capacitor 29 which can be regarded as part of the dc circuit, since it stabilizes the voltage of the dc circuit. The converter circuit 30 furthermore comprises a current converter having three parallel connection branches between opposite poles of the direct current circuit. Each branch comprises two controllable converter switches 25a, 25b;25c, 25d;25e, 25f. The operation of the converter switch 25 is controlled by a converter control device (not shown in fig. 7). Each converter switch 25 has an antiparallel diode 26a, 26b;26c, 26d;26e, 26f, the current converter may thus operate as a passive rectifier. The diode 26 also participates in inverting the direct current from the direct current circuit 21 in a plurality of operating states of the current converter.

The output side of the current converter has three ac phase lines. Each phase line is connected to a connection point between two converter switches 25 in one of the branches. The phase lines connect the current transformer with the primary side of a transformer 28, the transformer 28 preferably being an electrically insulating transformer. A capacitor circuit 27 is connected to the secondary side of the transformer 28. The ac line switch 12 is adapted to disconnect the converter circuit 30 from an ac line not shown in fig. 7. The ac power line may be the ac power line 15 shown in fig. 4 to 6.

With reference to fig. 8, the method of operation of the rail vehicle described above will be illustrated: in a first step S1, the designated current collector of the first converter reaches the segmentation point. In a following step S2, the converter control means of the first converter detects that the energy supply through the designated current collector has been stopped, for example in the manner described with reference to fig. 5. In the next step S3, the control device stops operating the changeover switch of the current converter. In particular, all converter switches remain in an off state.

In a following step S4, the phase current in the output-side alternating current line of the first converter (e.g. line 15 in fig. 5) is measured and the corresponding sensor result is evaluated to check if a high current, for example indicating a regenerative braking of the rail vehicle, is present. As indicated by the three arrows on the right side of the block representing step S4 in fig. 8, this process is repeated in case the energy flowing from the energy supply network to the input side of the first converter is interrupted. If the converter control detects the occurrence of a large current in step S4, the line switch on the output side of the first converter is opened in step S4 a. The line switch may remain open or may be closed again, depending on the continuous monitoring of the alternating current in step S4. When the line is in an off state, energy may flow from the output side of the first converter to the input side, i.e. the alternating current at the output side is rectified to a direct current at the input side, as shown in step S5.

Step S6 is performed in parallel with steps S4, S4a and S5, wherein the phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter is continuously processed during the period of time when the energy flow from the designated collector to the input side of the first converter is interrupted. In the next step S8, a return of the energy flow is detected and the inverting operation of the first converter is restarted, for example as described with reference to fig. 6.

Fig. 9 shows the case of the current I in an ac line (e.g., ac line 15 in fig. 4-6) before, during and after the designated collector of the first converter passes the segmentation point. The current I is shown as a function of time t. The current I is periodic before the switching (inverting) operation of the first converter, i.e. generating an alternating current at its output side, stops at time t 0. Immediately after time t0, the current drops to zero. At time t1, the conversion operation resumes. In the subsequent period up to time t2, the generated alternating current is not periodically stabilized due to the inductance and capacitance. The converter control preferably ignores the phase information during the period from time t1 to time t2, since the phase information acquired during this time interval may be distorted depending on the location of the information source, e.g. the sensor location of the ac line sensor 18a in fig. 4 to 6.

List of reference numerals

1. Rail vehicle

3a, 3b current collector

5. Railway system

6. Energy supply network

Overhead line section of 6a, 6b energy supply network

7. The energy supply network has segmented points with gaps between segments

11a, 11b current converter

12a, 12b ac line switch

13a, 13b main inductance

14a, 14b DC circuits

15. AC power line

16a converter control device

17a DC circuit sensor

18a alternating current line sensor

20. DC power supply

21. DC circuit

22. Switch

23. Inductance

24. Switchable resistor

25a to 25f converter switch

26a to 26f diodes

27. Capacitor circuit

28. Transformer

29. Capacitor with a capacitor body

30. Converter circuit

Claims

1. A method of operating a rail vehicle (1), the rail vehicle (1) comprising:

-a plurality of current collectors (3), each current collector (3) electrically connecting the rail vehicle (1) with an energy supply network (6);

-a plurality of converters including a first converter (11 a) and a second converter (11 b), each converter (11) being respectively assigned to a designated one (3) of the plurality of collectors (3) and converting a direct current at an input side of the converter (11) into an alternating current at an output side of the converter (11) by repeatedly switching on and off a converter switch (25) according to phase information about a phase position of an alternating voltage and/or a phase current at the output side of the converter (11);

An alternating current line (15) which electrically connects the output side of the converter (11),

wherein when the rail vehicle (1) passes through a segmentation point of the energy supply network (6), an interruption of the energy supply from the energy supply network (6) to the input side of the first converter (11 a) via a designated current collector (3) of the first converter (11 a) is caused,

a) Detecting the interrupt;

b) Stopping converting the direct current at the input side of the first converter (11 a) into alternating current at the output side of the first converter (11 a);

c) Continuing to process phase information about the phase position of the ac voltage and/or the ac current at the output side of the first converter (11 a) during the interrupted period of time;

d) -detecting a return of the energy supply network (6) to the input side of the first converter (11 a); and

e) The processing result of continuing to process the phase information during the interrupted period is used to restart the conversion of the direct current at the input side of the first converter (11 a) into an alternating current at the output side of the first converter (11 a).

2. The method according to claim 1, wherein the rail vehicle (1) comprises a line switch (12 a), the line switch (12 a) being controlled for opening and closing an electrical connection between the output side of the first converter (11 a) and the alternating current line (15), the line switch (12 a) having an open state and a closed state, the line switch (12 a) being kept in the closed state when an interruption is detected, such that an electrical connection between the output side of the first converter (11 a) and the alternating current line can be maintained.

3. Method according to claim 1 or 2, wherein the converter (11) is an auxiliary converter supplying electric energy via the alternating current line (15) to an auxiliary device of the rail vehicle (1), which auxiliary device supports the operation of the rail vehicle (1).

4. A method according to any one of claims 1 to 3, wherein the processing result is used to synchronize repeated switching on and off of a converter switch (25) of the first converter (11 a) with the phase position of the alternating voltage and/or alternating current at the output side of the first converter (11 a).

5. Method according to any one of claims 1 to 4, wherein the phase information about the phase position of the alternating voltage and/or alternating current at the output side of the first converter (11 a) is obtained from a sensor signal of an alternating current line sensor (18 a) for sensing the alternating voltage and/or alternating current at the output side of the first converter (11 a).

6. The method according to claim 5, wherein, in a period of time after restarting converting the direct current on the input side of the first converter (11 a) into the alternating current on the output side of the first converter (11 a), phase information about the phase position of the alternating voltage and/or the alternating current on the output side of the first converter (11 a) is ignored when repeatedly switching on and off the converter switch (25) of the first converter (11 a).

7. A rail vehicle (1) comprising:

-a plurality of current collectors (3), each current collector (3) being adapted to electrically connect the rail vehicle (1) with an energy supply network;

-a plurality of converters, including a first converter (11 a) and a second converter (11 b), each converter (11) being respectively assigned to a designated one (3) of the plurality of collectors (3) and being adapted to convert a direct current at an input side of the converter (11) into an alternating current at an output side of the converter (11) by repeatedly switching on and off a converter switch (25) depending on phase information about a phase position of an alternating voltage and/or a phase current at the output side of the converter (11);

-an alternating current line (15) adapted to electrically connect the output side of the converter;

-one or more supply presence sensors adapted to generate a sensor signal indicating whether there is a supply of electrical energy from the energy supply network through a designated current collector (3) of the first converter (11 a) to the input side of the first converter (11 a);

first converter control means adapted to control the operation of said first converter (11 a),

Wherein when the rail vehicle (1) passes a segmentation point of the energy supply network (6), an interruption of the energy supply from the energy supply network through a designated current collector (3) of the first converter (11 a) to the input side of the first converter (11 a) is caused, the rail vehicle (1) being adapted to:

d) Detecting a return of the energy supply network to the energy supply of the input side of the first converter (11 a) from the sensor signal of the supply presence sensor;

e) Using the processing result of continuing to process the phase information during the interrupted period, the conversion of the direct current on the input side of the first converter (11 a) into the alternating current on the output side of the first converter (11 a) is restarted.

8. A rail vehicle as claimed in claim 7, wherein the rail vehicle (1) comprises a line switch (12 a) controlled for opening and closing an electrical connection between the output side of the first converter (11 a) and the alternating current line (15), the line switch (12 a) having an open state and a closed state, and

When an interruption is detected, the railway vehicle (1) is adapted to keep the line switch (12 a) in a closed state, so that an electrical connection between the output side of the first converter (11 a) and the alternating current line (15) can be maintained.

9. Rail vehicle according to claim 7 or 8, wherein the converter is an auxiliary converter adapted to supply an auxiliary device of the rail vehicle (1) with electrical energy via the alternating current line (15), the auxiliary device being adapted to support the operation of the rail vehicle (1).

10. Rail vehicle of any of the claims 7-9, wherein the first converter control means are adapted to use the result of the processing to synchronize the repeated switching on and off of the converter switch (25) of the first converter (11 a) with the phase position of the alternating voltage and/or alternating current at the output side of the first converter (11 a).

11. Rail vehicle of any of the claims 7-10, wherein the rail vehicle (1) comprises an alternating current line sensor (18 a), the alternating current line sensor (18 a) being adapted to sense an alternating voltage and/or an alternating current at the output side of the first converter (11 a), the rail vehicle (1) being adapted to obtain phase information about the phase position of the alternating voltage and/or the alternating current at the output side of the first converter (11 a) from a sensor signal of the alternating current line sensor (18 a).

12. Rail vehicle according to claim 11, wherein the first converter control means are adapted to control repeated switching on and off of the converter switch (25) of the first converter (11 a) ignoring phase information about the phase position of the alternating voltage and/or the alternating current of the output side of the first converter (11 a) during a period of time after restarting converting the direct current of the input side of the first converter (11 a) into the alternating current of the output side of the first converter (11 a).