Maglev train power supply device and method

Abstract

The present invention provides a power supply device and method for a maglev train, the power supply device comprising: a plurality of converters and a controller, the traction inverter module in the converter comprising a switcher and a plurality of inverter basic units connected in series, the working state of the inverter basic unit comprising an inductance mode and a transformer mode, the inverter basic unit comprising an inverter and a transformer, for any working converter, the working state of the plurality of inverter basic units at different maglev train running speeds is changed by the switcher, and at the same time, the controller cooperates with the switcher to adjust the output of the plurality of inverter basic units at different maglev train running speeds. The method of the present invention can solve the technical problem that the output voltage of the existing power supply method is insufficient in a single inductance mode and cannot meet the traction requirements.

Description

Technical Field

[0001] The present invention belongs to the technical field of maglev traction control, in particular to traction inverter control of an ultra-high-speed maglev train, and specifically relates to a maglev train power supply device and method. Background Art

[0002] The ultra-high-speed maglev train is driven by a superconducting linear motor. The system requires a large-capacity traction inverter to drive the train. The traction inverter has two output modes: inductor mode and transformer mode. However, if the output frequency is low, since the inverter must have an output transformer, the DC bias will cause the transformer to be magnetically biased. Therefore, the inductor mode is used for direct output in the low-frequency region, and then switched to the transformer mode after a certain frequency.

[0003] Since the ground traction power supply system of the maglev train adopts a segmented power supply mode, the switching between the inductance mode and the transformer mode is completed during the segmentation process. The existing solution is to use the same voltage output mode within a segment and switch from the inductance mode to the transformer mode after the segmentation is completed. When the segment length is fixed, the inverter output frequency will exceed the working range of the inductance mode before the mode switching point, causing the inverter output voltage to tend to saturation and fail to reach the theoretical output voltage, resulting in a decrease in train thrust and failure to meet traction requirements. Summary of the invention

[0004] The present invention provides a power supply device and method for a magnetic levitation train to solve the technical problems existing in the above-mentioned prior art.

[0005] The technical solution of the present invention is:

[0006] According to one aspect, a power supply device for a maglev train is provided, the power supply device comprising: a plurality of converters and a controller, the plurality of converters being used to supply power to the maglev train in sections, any of the converters comprising a traction inverter module; wherein the traction inverter module comprises a switcher and a plurality of inverter basic units connected in series, the working states of the inverter basic units comprising an inductor mode and a transformer mode, the inverter basic units comprising an inverter and a transformer, and for any working converter, the working states of the plurality of inverter basic units at different maglev train operating speeds are changed by the switcher, and at the same time, the controller cooperates with the switcher to control the outputs of the plurality of inverter basic units at different maglev train operating speeds.

[0007] Furthermore, the step of changing the working states of the multiple inverter basic units at different maglev train running speeds by the switcher, and adjusting the outputs of the multiple inverter basic units at different maglev train running speeds by the controller in coordination with the switcher includes:

[0008] When the running speed of the maglev train is less than the first set threshold, the switch controls the first path to connect and output the first voltage; in the first path state, one of the multiple inverter basic units works in the inductance mode, and the remaining inverter basic units work in the transformer mode, and the first voltage is output by the controller controlling the inverter basic unit working in the inductance mode; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0;

[0009] When the running speed of the maglev train is greater than or equal to a first set threshold and less than a second set threshold, the switch controls the first path to connect and output a second voltage, and the controller controls the second voltage to be outputted by a plurality of inverter basic units in different working modes and adjusts the output voltages of the plurality of inverters in different working modes;

[0010] When the running speed of the maglev train is greater than or equal to the second set threshold, the switch controls the second path to connect and output the third voltage; in the second path state, the plurality of inverter basic units all work in the transformer mode, and the controller controls the third voltage to be jointly provided by the plurality of inverter basic units working in the transformer mode;

[0011] When the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequencies in the inductance mode and the transformer mode overlap.

[0012] Furthermore, the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes, including:

[0013] The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer mode o2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1 and u o2 They are shown as follows:

[0014] u o1 =(1-a)*u;

[0015] u o2 =a*u;

[0016] Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

[0017] Furthermore, the traction inverter module includes four inverter basic units connected in series.

[0018] Furthermore, the inverter basic unit is composed of two series-connected inverters and a transformer.

[0019] Furthermore, the inverter is a three-level inverter, and the transformer is an open-winding transformer.

[0020] Furthermore, the first set threshold includes 108 km / h; the second set threshold includes 140.4 km / h.

[0021] According to another aspect, a method for powering a maglev train is provided, and the method supplies power to the maglev train based on the power supply device mentioned above.

[0022] Furthermore, the power supply method comprises:

[0023] Step 1, judging the running speed of the maglev train in real time, wherein, when the running speed of the maglev train is less than the first set threshold, proceed to step 2; when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, proceed to step 3; when the running speed of the maglev train is greater than or equal to the second set threshold, proceed to step 4, wherein, when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequency of the inductor mode and the transformer mode overlap;

[0024] Step 2: The switch controls the first path to connect and output a first voltage; in the first path state, one of the multiple inverter basic units works in an inductor mode, and the remaining inverter basic units work in a transformer mode, and the controller controls the inverter basic unit working in the inductor mode to output the first voltage; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0;

[0025] Step 3: The switch controls the first path to connect and output a second voltage, and the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes;

[0026] Step 4: The switch controls the second path to connect and output a third voltage; in the second path state, multiple inverter basic units all work in transformer mode, and the controller controls the third voltage to be jointly provided by multiple inverter basic units working in transformer mode.

[0027] Furthermore, in step three, the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes, including:

[0028] The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer mode o2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1 and u o2 They are shown as follows:

[0029] u o1 =(1-a)*u;

[0030] u o2 =a*u;

[0031] Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

[0032] By applying the above technical solution, the traction inverter module in the converter is configured to include a plurality of inverter basic units connected in series, and a control strategy is designed so that the switch and the controller cooperate to control the working state and output of the plurality of inverter basic units connected in series. In this way, when the output voltage of the inductor mode inverter is insufficient (the operating frequency of the inductor mode inverter and the operating frequency of the transformer mode inverter overlap), the present invention only needs to control the series output of the inductor mode basic unit and the transformer mode basic unit by switching the switch, and cooperate with the controller to adjust the output voltage of the basic unit in different working states (for example, gradually reduce the voltage allocated to the inductor mode basic unit, and gradually increase the voltage allocated to the basic unit in the transformer mode), so that the basic units in different working states work together to output the required voltage, which can overcome the problem of insufficient output voltage of a single inductor mode inverter to meet the traction demand, and solve the problem of thrust reduction caused by insufficient output voltage of a single inductor mode inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The schematic diagram of the internal structure of the existing traction substation is shown;

[0034] Figure 2 The existing double-end power supply traction power supply system architecture of maglev train is shown;

[0035] Figure 3 A schematic structural diagram of a traction inverter module provided according to an embodiment of the present invention is shown;

[0036] Figure 4 The inductor and transformer mode switching strategy provided according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0039] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0040] In one embodiment of the present invention, a power supply device for a maglev train is provided, the power supply device comprising a plurality of converters and a controller, the plurality of converters being used to supply power to the maglev train in sections, any of the converters comprising a traction inverter module; wherein the traction inverter module comprises a switcher and a plurality of inverter basic units connected in series, the working states of the inverter basic units comprising an inductor mode and a transformer mode, the inverter basic units comprising an inverter and a transformer, and for any working converter, the working states of the plurality of inverter basic units at different maglev train operating speeds are changed by the switcher, and at the same time, the controller cooperates with the switcher to control the outputs of the plurality of inverter basic units at different maglev train operating speeds.

[0041] That is, the innovative design of the traction inverter module in the embodiment of the present invention includes multiple inverter basic units connected in series, and the multiple inverter basic units are enabled to work in different modes through a switch. Those skilled in the art know that when the inverter is connected to the inductor, it works in the inductor mode, and when the inverter is connected to the transformer, it works in the transformer mode. At this time, the working state of the inverter basic unit can be changed through the switch so that it has two working modes. The specific design means are easy to implement (for example, adding a tap output in the middle of the primary winding of the transformer), which will not be described in detail here.

[0042] The switch is a switching device, such as a switch, etc. The embodiment of the present invention does not specifically limit this and can be selected according to actual needs.

[0043] like Figure 1 As shown, Figure 1 The figure shows a schematic diagram of the internal structure of an existing traction substation, that is, an existing maglev train power supply equipment, including three converters. The converter as a whole can be regarded as comprising a rectifier module and a traction inverter module. Each converter consists of an input switch, an input transformer, an input rectifier, a DC connection, an output inverter, an output transformer and an output switch. The input switch is connected to the input transformer and then to the input rectifier to convert three-phase AC power into DC power, and then connected to the output inverter through a DC connection link to convert DC power into AC power, which is output through the subsequently connected output transformer and output switch. The input switch, input transformer and input rectifier constitute a rectifier module, and the output inverter, output transformer and output switch constitute a traction inverter module.

[0044] like Figure 3As shown, the power supply device of the embodiment of the present invention improves the traction inverter module in the converter. In order to achieve a higher output voltage level, a new topology is designed based on the current output of only one transformer, that is, a basic unit is composed of an inverter and a transformer, and each phase of the three-phase AC is composed of four basic units in series. The electric energy is output through the output transformer and the output switch (switcher) through the line cable to power the ground module of the maglev train motor.

[0045] Since the traction inverter module in the converter is configured to include a plurality of inverter basic units connected in series, and a control strategy is designed so that the switch and the controller cooperate to control the working state and output of the plurality of inverter basic units connected in series, when the output voltage of the inductor mode inverter is insufficient (the operating frequency of the inductor mode inverter and the operating frequency of the transformer mode inverter overlap), the present invention only needs to control the series output of the inductor mode basic unit and the transformer mode basic unit by switching the switch, and cooperate with the controller to adjust the output voltage of the basic units in different working states (for example, gradually reduce the allocated voltage of the inductor mode basic unit, and gradually increase the allocated voltage of the basic unit in the transformer mode), so that the basic units in different working states work together to output the required voltage, which can overcome the problem of insufficient output voltage of a single inductor mode inverter to meet traction requirements, and solve the problem of thrust reduction caused by insufficient output voltage of a single inductor mode inverter.

[0046] In the above embodiment, the step of changing the working states of the multiple inverter basic units at different maglev train running speeds by the switch, and adjusting the outputs of the multiple inverter basic units at different maglev train running speeds by the controller in coordination with the switch includes:

[0047] When the running speed of the maglev train is less than the first set threshold, the switch controls the first path to connect and output the first voltage; in the first path state, one of the multiple inverter basic units works in the inductance mode, and the remaining inverter basic units work in the transformer mode, and the first voltage is output by the controller controlling the inverter basic unit working in the inductance mode; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0;

[0048] When the running speed of the maglev train is greater than or equal to a first set threshold and less than a second set threshold, the switch controls the first path to connect and output a second voltage, and the controller controls the second voltage to be outputted by a plurality of inverter basic units in different working modes and adjusts the output voltages of the plurality of inverters in different working modes;

[0049] When the running speed of the maglev train is greater than or equal to the second set threshold, the switch controls the second path to connect and output the third voltage; in the second path state, the plurality of inverter basic units all work in the transformer mode, and the controller controls the third voltage to be jointly provided by the plurality of inverter basic units working in the transformer mode;

[0050] When the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequencies in the inductance mode and the transformer mode overlap.

[0051] Those skilled in the art know that the higher the operating frequency of the inverter, the higher its output voltage is, and the corresponding train speed is also higher.

[0052] In this embodiment, Figure 3-4As shown, as mentioned in the background technology, when the maglev train is powered and driven, the inductive mode is required to directly output the voltage in the initial stage (low-frequency area, low speed), that is, when the running speed of the maglev train is less than the first set threshold, the inverter operating frequency is in the inductive mode inverter operating frequency (excluding the above-mentioned overlap interval). At this time, SW1 is closed, one of the multiple inverter basic units works in the inductive mode, and the remaining inverter basic units work in the transformer mode. In order to prevent the transformer from saturating in the low-speed area, at this time, the controller controls the output voltage of the remaining inverter basic units to be 0, and the first voltage is provided by the inverter basic unit working in the inductive mode, which can prevent the transformer from saturating in the low-speed area (the output of the transformer mode inverter basic unit is 0), and because the output of the remaining inverter basic units is 0, it is equivalent to the equivalent series inductance, that is, the leakage inductance of the transformer is used to increase the impedance of the system, thereby reducing the loop of the system. Flow; With the increase of the speed, when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, that is, the operating frequency of the inductor mode inverter and the transformer mode inverter overlap (only the inductor mode inverter voltage output can be used at present), at this time, SW1 is still closed, different from the previous speed interval, the controller controls and adjusts the output voltage of multiple inverter basic units in different working modes at this time, that is, the second voltage is jointly provided by multiple inverter basic units in different working states, so that the problem of insufficient voltage supply in a certain segment can be ensured when the segment length is fixed; then, when the running speed of the maglev train is greater than or equal to the second set threshold, that is, at this time, the inverter operating frequency reaches the transformer mode inverter operating frequency, at this time, SW2 is closed, multiple inverter basic units all work in the transformer mode, and the third voltage is jointly provided by multiple inverter basic units working in the transformer mode. It can be seen that the embodiment of the present invention not only realizes the smooth switching from the inductor mode to the transformer mode, but also solves the problem of thrust reduction caused by insufficient output voltage of a single inductor mode inverter basic unit.

[0053] In the above embodiment, in order to prevent the power supply saturation of the inverter in the existing inductive mode, configuring the controller to control the second voltage to be outputted by multiple inverter basic units in different working modes and adjusting the output voltages of multiple inverters in different working modes includes:

[0054] The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer mode o2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1and u o2 They are shown as follows:

[0055] u o1 =(1-a)*u;

[0056] u o2 =a*u;

[0057] Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

[0058] That is, when the running speed of the maglev train is less than the first set threshold, the voltage distribution coefficient is 0. At this time, since the train is in a low-speed state, the inductive mode inverter basic unit can fully bear the voltage output. When the running speed of the maglev train is greater than or equal to the second set threshold, the running speed of the train is already very high and can enter the transformer mode power supply state. At this time, the corresponding voltage distribution coefficient is 1, and the controller further controls u o2 Provided by all inverter basic units, all inverter basic units work in transformer mode.

[0059] In this configuration, when the train starts at a low speed, an inductor mode inverter basic unit is connected in series with another multiple transformer mode inverter basic unit, the output mode switching switch SW1 is closed and SW2 is opened, and the voltage distribution coefficient a is set to 0 at the beginning. The motor voltage is all provided by a heavy inductor mode inverter basic unit, and the output voltage of the other multiple transformer mode inverter basic unit is zero. As the speed increases, the output voltage required by the traction inverter increases. When the inverter output frequency is in the above overlap range and the inductor mode output voltage tends to saturation, the voltage distribution coefficient a is gradually increased, such as Figure 4 As shown, the basic unit of the inductor mode inverter will not enter the voltage saturation area, and the basic unit of the transformer mode inverter starts to work normally to output voltage and share the remaining voltage. Through such control, the voltage shared by the basic unit of the transformer mode inverter is suppressed to the minimum as much as possible, thereby reducing the burden on the output transformer and preventing the integral saturation of the transformer at low frequency.

[0060] In the above embodiment, in order to ensure the power supply voltage of the train and save costs at the same time, the traction inverter module includes four inverter basic units connected in series.

[0061] In the above embodiment, in order to ensure that the power supply voltage is met at different train speeds, the inverter basic unit is composed of two series-connected inverters and transformers.

[0062] As a specific embodiment of the present invention, the inverter is a three-level inverter, the transformer is an open-winding transformer, and the traction inverter module includes four inverter basic units connected in series, and the basic unit is composed of two three-level inverters connected in series and further connected in series with an open-winding transformer.

[0063] In the above embodiment, according to actual conditions, the first set threshold includes 108 km / h; the second set threshold includes 140.4 km / h.

[0064] That is, as a specific embodiment of the present invention, the inverter operating frequency in the inductive mode is 0-13Hz (corresponding to a train speed of 0km / h-140.4km / h), and the inverter operating frequency in the transformer mode is 10Hz and above (corresponding to a train speed of 108km / h and above), and the above-mentioned overlapping interval is 10-13Hz.

[0065] According to another embodiment, a method for powering a maglev train is provided. The method powers the maglev train based on the power supply device described above.

[0066] In the above embodiment, the power supply method includes:

[0067] Step 1, judging the running speed of the maglev train in real time, wherein, when the running speed of the maglev train is less than the first set threshold, proceed to step 2; when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, proceed to step 3; when the running speed of the maglev train is greater than or equal to the second set threshold, proceed to step 4, wherein, when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequency of the inductor mode and the transformer mode overlap;

[0068] Step 2: The switch controls the first path to connect and output a first voltage; in the first path state, one of the multiple inverter basic units works in an inductor mode, and the remaining inverter basic units work in a transformer mode, and the controller controls the inverter basic unit working in the inductor mode to output the first voltage; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0;

[0069] Step 3: The switch controls the first path to output a second voltage, and the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes;

[0070] Step 4: The switch controls the second path to connect and output a third voltage; in the second path state, multiple inverter basic units all work in transformer mode, and the controller controls the third voltage to be jointly provided by multiple inverter basic units working in transformer mode.

[0071] Applying this control strategy, when the running speed of the maglev train is less than the first set threshold, the inverter operating frequency is in the inductive mode inverter operating frequency (excluding the above-mentioned overlap interval). At this time, SW1 is closed, one of the multiple inverter basic units works in the inductive mode, and the remaining inverter basic units work in the transformer mode. In order to prevent the transformer from saturating in the low-speed area, at this time, the controller controls the output voltage of the remaining inverter basic units to be 0, and the first voltage is provided by the inverter basic unit working in the inductive mode. In this way, the transformer saturation in the low-speed area (the output of the transformer mode inverter basic unit is 0) can be prevented, and since the output of the remaining inverter basic units is 0, it is equivalent to the equivalent series inductance, that is, the leakage inductance of the transformer is used to increase the impedance of the system and reduce the circulating current of the system; as the speed increases, when the running speed of the maglev train is greater than or equal to When the first set threshold is less than the second set threshold, that is, the operating frequency of the inductor mode inverter and the operating frequency of the transformer mode inverter overlap (only the inductor mode inverter voltage output can be used at present), at this time, SW1 is still closed. Different from the previous speed interval, the controller controls and adjusts the output voltage of multiple inverter basic units in different working modes at this time, that is, the second voltage is jointly provided by multiple inverter basic units in different working states, so that the problem of insufficient voltage supply in a certain segment can be ensured when the segment length is fixed; then, when the running speed of the maglev train is greater than or equal to the second set threshold, that is, at this time, the inverter operating frequency reaches the transformer mode inverter operating frequency, at this time, SW2 is closed, multiple inverter basic units all work in the transformer mode, and the third voltage is jointly provided by multiple inverter basic units working in the transformer mode. It can be seen that the embodiment of the present invention not only realizes the smooth switching from the inductor mode to the transformer mode, but also solves the problem of thrust reduction caused by insufficient output voltage of a single inductor mode inverter basic unit.

[0072] In the above embodiment, in order to prevent the power supply saturation of the inverter in the existing inductive mode, in step three, the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes, including:

[0073] The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer modeo2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1 and u o2 They are shown as follows:

[0074] u o1 =(1-a)*u;

[0075] u o2 =a*u;

[0076] Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

[0077] Furthermore, the specific application of the above power supply method is illustrated by examples:

[0078] High-speed maglev uses a dual-end power supply method, and its traction power supply system architecture is as follows Figure 2 As shown, the mode switching control is mainly aimed at the change of the working mode state of the traction inverter. The parallel output of the double-ended converter provides power to the power supply section. Each power supply section contains a ground module to provide power for the train operation. For example, the initial position of the train is position 1. At this time, the ground modules on both sides of the track are powered by the No. 1 double-ended parallel traction converter and the No. 3 device respectively. The train starts, the train moves forward and accelerates, and the speed gradually increases. When the train travels to position 2, the working frequency of the inverter is in the overlap range of the inductor output mode and the transformer mode working frequency (10-13Hz). Therefore, when entering the next ground module, the working mode of the No. 2 device is switched to the transformer mode. At this time, after entering the No. 2 power supply section, the ground modules on both sides of the track are powered by the No. 1 inductor mode converter and the No. 2 transformer mode converter respectively. After that, it enters the No. 3 transformer mode power supply section to complete the switch from the inductor mode to the transformer mode.

[0079] From the above workflow, it can be seen that the traction inverter works in the inductive mode in the inductive mode area of ​​the figure, and works in the transformer mode in the subsequent transformer mode area. When the power supply segment length is fixed, for different train speeds, the traction inverter output frequency will exceed the working range of the inductive mode before the mode switching point, resulting in insufficient converter output voltage and reduced train thrust.

[0080] In order to solve the problem of insufficient voltage output during mode switching, when the inverter operating frequency is in the interval where the inverter operating frequency in the inductor mode and the transformer mode overlap, an inductor and transformer voltage distribution strategy is designed. Figure 3 , its output voltage is according to the formula u o1 =(1-a)*u and u o2=a*u distribution output, a is the voltage distribution coefficient, u is the total output voltage of the converter, u o1 is the output voltage of the basic unit of the inductive mode inverter, u o2 Output voltage for the basic unit of the multi-transformer mode inverter.

[0081] In order to achieve smooth switching between inductor and transformer modes, when the train starts at low speed, an inductor mode inverter basic unit is connected in series with another multiple transformer mode inverter basic unit, the output mode switching switch SW1 is closed and SW2 is opened. At the beginning, the voltage distribution coefficient a is set to 0, and the motor voltage is all provided by a heavy inductor mode inverter basic unit. The output voltage of the other multiple transformer mode inverter basic unit is zero. As the speed increases, the output voltage required by the traction inverter increases. When the inverter output frequency is in the above overlap range and the inductor mode output voltage tends to saturation, the voltage distribution coefficient a is gradually increased, such as Figure 4 As shown, the basic unit of the inductor mode inverter will not enter the voltage saturation area, and the basic unit of the transformer mode inverter starts to work normally to output voltage and share the remaining voltage, that is, the power supply in the inductor mode area is completed according to this strategy; after the train continues to run and completes the segmentation, it enters Figure 2 In the transformer mode area shown, adjust the output switching switch of the inductor mode inverter basic unit to switch the first inductor mode to the transformer mode, SW1 is disconnected and SW2 is closed, so as to output in series with other multiple transformer mode inverter basic units. At this time, multiple transformer outputs share the converter output voltage and work in a single transformer output mode.

[0082] It can be seen that the method of the present invention enables the modulation wave of the basic unit of a heavy inductance mode inverter to be controlled to the linear modulation area, and the inductance mode is immediately switched to the transformer mode after crossing the transition process, which is a power supply segment, thereby achieving smooth switching between the inductance and transformer modes and solving the problem of reduced train thrust.

[0083] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0084] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0085] The above method of the present invention can be implemented by hardware, or by hardware combined with software. The present invention relates to such a computer-readable program, which, when executed by a logic component, enables the logic component to implement the above-mentioned device or component, or enables the logic component to implement the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0086] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0087] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A power supply device for a maglev train, the power supply device comprising: A plurality of converters and controllers, wherein the plurality of converters are used to supply power to a maglev train in sections, and any of the converters includes a traction inverter module; characterized in that the traction inverter module includes a switch and a plurality of inverter basic units connected in series, the working state of the inverter basic unit includes an inductor mode and a transformer mode, and the inverter basic unit includes an inverter and a transformer; for any of the converters in operation, the working state of the plurality of inverter basic units at different maglev train operating speeds is changed by the switch, and at the same time, the controller cooperates with the switch to control the output of the plurality of inverter basic units at different maglev train operating speeds, specifically including: When the running speed of the maglev train is less than the first set threshold, the switch controls the first path to connect and output the first voltage; in the first path state, one of the plurality of inverter basic units works in the inductance mode, and the remaining inverter basic units work in the transformer mode, and the first voltage is output by the inverter basic unit controlled by the controller to work in the inductance mode; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0; When the running speed of the maglev train is greater than or equal to a first set threshold and less than a second set threshold, the switch controls the first path to connect and output a second voltage, and the controller controls the second voltage to be outputted by a plurality of the inverter basic units in different working modes and adjusts the output voltages of the plurality of the inverters in different working modes; When the running speed of the maglev train is greater than or equal to the second set threshold, the switch controls the second path to connect and output the third voltage; in the second path state, the plurality of inverter basic units all work in the transformer mode, and the controller controls the third voltage to be jointly provided by the plurality of inverter basic units working in the transformer mode; When the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequencies in the inductor mode and the transformer mode overlap.

2. A maglev train power supply device according to claim 1, characterized in that: The controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes, including: The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer mode o2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1 and u o2 They are shown as follows: u o1 =(1-a)*u; u o2 =a*u; Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

3. A maglev train power supply device according to any one of claims 1-2, characterized in that: The traction inverter module includes four inverter basic units connected in series.

4. A maglev train power supply device according to claim 3, characterized in that: The inverter basic unit is composed of two inverters and a transformer connected in series.

5. A maglev train power supply device according to claim 4, characterized in that: The inverter is a three-level inverter, and the transformer is an open-winding transformer.

6. A maglev train power supply device according to claim 1, characterized in that: The first set threshold includes 108 km / h; the second set threshold includes 140.4 km / h.

7. A method for supplying power to a maglev train, characterized in that: The method supplies power to a maglev train based on the power supply device according to any one of claims 1 to 6.

8. A method for supplying power to a maglev train according to claim 7, characterized in that: The power supply method comprises: Step 1, judging the running speed of the maglev train in real time, wherein, when the running speed of the maglev train is less than the first set threshold, proceed to step 2; when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, proceed to step 3; when the running speed of the maglev train is greater than or equal to the second set threshold, proceed to step 4, wherein, when the running speed of the maglev train is greater than or equal to the first set threshold and less than the second set threshold, the corresponding inverter operating frequency is in the interval where the inverter operating frequency of the inductor mode and the transformer mode overlap; Step 2: The switch controls the first path to connect and output a first voltage; in the first path state, one of the multiple inverter basic units works in an inductor mode, and the remaining inverter basic units work in a transformer mode, and the controller controls the inverter basic unit working in the inductor mode to output the first voltage; at the same time, the controller also controls the output voltage of the remaining inverter basic units to be 0; Step 3: The switch controls the first path to output a second voltage, and the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes; Step 4: The switch controls the second path to connect and output a third voltage; in the second path state, multiple inverter basic units all work in transformer mode, and the controller controls the third voltage to be jointly provided by multiple inverter basic units working in transformer mode.

9. A method for powering a maglev train according to claim 8, characterized in that: In step three, the controller controls the second voltage to be outputted by multiple inverter basic units in different working modes and adjusts the output voltages of multiple inverters in different working modes, including: The controller adjusts the voltage distribution coefficient a to achieve the output voltage u of the inverter basic unit working in the inductive mode. o1 The total output voltage u of the remaining inverter basic units working in transformer mode o2 As the speed of the maglev train increases, the controller controls the voltage distribution coefficient a to increase gradually; wherein the output voltage u o1 and u o2 They are shown as follows: u o1 =(1-a)*u; u o2 =a*u; Where, u is the total output voltage of the converter; a is the voltage distribution coefficient.

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