Single-phase / three-phase compatible AC-DC-AC traction converter and high-speed train power supply transmission system

Abstract

The present invention provides a single-phase / three-phase compatible AC-DC-AC traction converter, which includes a plurality of rectifier-side power tube bridge arms, and further includes three rectifier-side input terminals connected to corresponding rectifier-side power tube bridge arms by a rectifier-side inductor and a transfer switch, and by changing the open / close state of the transfer switch, the rectifier side of the AC-DC-AC traction converter can accommodate both external three-phase power input and external single-phase power input, and when the external three-phase power input is input, the plurality of rectifier-side power tube bridge arms work as a three-phase rectifier circuit, and when the external single-phase power input is input, the plurality of rectifier-side power tube bridge arms work as a single-phase rectifier circuit. The present invention can accommodate both three-phase AC input and single-phase AC input, has a wide range of application, and does not require a single-phase input terminal in addition to the three-phase input terminal, making the wiring simple.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Chinese Patent Application No. 202111373498.2, filed on November 19, 2021, the contents of which are incorporated herein by reference.

[0002] The present invention relates to the field of converters, and in particular to a single-phase and three-phase compatible AC-DC-AC traction converter and a high-speed train power supply transmission system. [Background technology]

[0003] Conventional traction power supplies for rail transit systems, such as subways and light rail, mostly use a 1500V DC system. While DC systems offer advantages such as phaseless power supply and smooth train operation, they also necessitate the installation of expensive inverters and energy storage devices due to the difficulty of directly or economically utilizing regenerative energy, which accounts for approximately 30-50% of traction energy consumption. Furthermore, if the inverters or energy storage devices fail, the train's regenerative braking may become ineffective, causing it to switch to air braking, threatening operational safety. Furthermore, the stray currents present can cause electrochemical corrosion in surrounding metal pipes and building steel structures, a problem that has yet to be resolved, resulting in widespread and long-term damage.

[0004] As a result, with demand for faster speeds and greater transport capacity, rail transit in some large cities currently has no choice but to use single-phase power frequency 25kV AC on main railways in addition to DC systems.The advantages of this system are high power supply capacity and simple system configuration, but the disadvantages are that the on-board transformers are heavy and bulky, taking up valuable space on high-speed trains and increasing axle loads, which affects passenger transport efficiency.

[0005] Currently, single-phase power frequency AC power supply is the mainstream for AC traction power supply in the field of rail transit technology. However, three-phase generators, motors, transformers, and transmission lines all require less material and are simpler in structure than similar single-phase components under the same power supply capacity, and the instantaneous power value of three-phase power is kept constant. In this regard, the inventors of the present application have proposed a ground three-phase traction power supply and an on-board three-phase power supply system (see Chinese patent application "Three-Phase Traction Power Supply System" with application number ZL201721675432.8). Furthermore, to solve the compatibility issue between on-board three-phase power supply transmission and single-phase power supply transmission, the inventors of the present application have also proposed a "High-Speed ​​Train Power Supply Transmission System, AC-DC-AC Traction Converter, and Control Method Thereof" (CN113799663A). These technical measures overcome the shortcomings of the existing 1500V DC system and also the shortcomings of the single-phase power frequency 25kV AC system, achieving compatibility and versatility between three-phase and single-phase on-board power supply (traction transmission) systems, and compatibility between ground three-phase and single-phase traction transmission systems.

[0006] The current technical challenge to be solved is how to achieve compatibility between three-phase and single-phase on-board power supply (traction transmission) systems and solve the problem of optimal structure and conversion for on-board AC-DC-AC traction drive converters that can handle both single-phase and three-phase inputs. Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above, the present invention provides a single-phase / three-phase compatible AC-DC-AC traction converter that is provided with a converter rectifier structure and an input terminal transfer switch, and that achieves optimal compatibility between single phase and three phase by closing or opening the transfer switch. Specifically, in three-phase AC input mode, the three rectifier input terminals form rectifier-side three-phase input terminals, and the converter rectifier side operates in three-phase rectification mode and as a three-phase rectifier circuit. In single-phase AC input mode, two of the three rectifier input terminals are connected to form another rectifier input terminal and a rectifier-side single-phase input terminal, and the converter rectifier side operates in single-phase rectification mode and as a single-phase rectifier circuit. [Means for solving the problem]

[0008] In order to achieve the above technical objectives, the specific technical means are as follows:

[0009] Single-phase and three-phase compatible AC-DC-AC traction converters The AC-DC-AC traction converter includes a plurality of rectifier-side power tube bridge arms, and further includes three rectifier-side input terminals connected to corresponding rectifier-side power tube bridge arms by rectifier-side inductors and transfer switches, and the rectifier side of the AC-DC-AC traction converter can accommodate both external three-phase power input and single-phase power input by changing the open / close state of the transfer switches; When an external three-phase power is input, the plurality of rectifier-side power tube bridge arms operate as a three-phase rectifier circuit; In the case of external single-phase power input, the plurality of rectifier-side power tube bridge arms operate as a single-phase rectifier circuit.

[0010] Furthermore, when external three-phase power is input, the multiple rectifier-side power tube bridge arms operate in a three-phase rectifier circuit, and each rectifier-side power tube bridge arm has the same current capacity; when external single-phase power is input, the multiple rectifier-side power tube bridge arms operate in a single-phase rectifier circuit, and each rectifier-side power tube bridge arm has the same current capacity.

[0011] The power supply further includes a rectifier-side power tube bridge arm LBA11, a rectifier-side power tube bridge arm LBA12, a rectifier-side power tube bridge arm LBB11, a rectifier-side power tube bridge arm LBB12, a rectifier-side power tube bridge arm LBC11, and a rectifier-side power tube bridge arm LBC12, which are connected in parallel between the positive DC bus BUS1+ and the negative DC bus BUS1-, The rectifier side power tube bridge arm LBA11, the rectifier side power tube bridge arm LBA12, the rectifier side power tube bridge arm LBB11, the rectifier side power tube bridge arm LBB12, the rectifier side power tube bridge arm LBC11, and the rectifier side power tube bridge arm LBC12 are provided with AC terminal points a11, a12, b11, b12, c11, and c12, respectively. The terminal point a12, the AC terminal point b11, the AC terminal point b12, the AC terminal point c11, and the AC terminal point c12 are connected to one end of the rectifier side inductor INA11, the rectifier side inductor INA12, the rectifier side inductor INB11, the rectifier side inductor INB12, the rectifier side inductor INC11, and the rectifier side inductor INC12, respectively. The other ends of the rectifier side inductor INA11 and the rectifier side inductor INA12 are connected to form a first input terminal A11 on the rectifier side. The other end of the inductor INC12 is connected to one end of a transfer switch K12, and the other end of the rectifier-side inductor INB11 is connected to one end of a transfer switch K13. The other ends of the transfer switches K12 and K13 are connected to one end of the transfer switch K13, and form a second input terminal A12 on the rectifier side. A transfer switch K11 is connected in parallel between the other end of the rectifier-side inductor INA12 connected opposite the rectifier-side power tube bridge arm LBA12 and the other end of the rectifier-side inductor INB11 connected opposite the rectifier-side power tube bridge arm LBB11. A transfer switch K14 is connected in parallel between the other end of the rectifier-side inductor INB12 connected opposite the rectifier-side power tube bridge arm LBB12 and the other end of the rectifier-side inductor INC11 connected opposite the rectifier-side power tube bridge arm LBC11.

[0012] Furthermore, when the transfer switches K11 and K14 are disconnected and the transfer switches K12 and K13 are closed, the first input terminal A11 on the rectification side, the second input terminal A12 on the rectification side, and the third input terminal A13 on the rectification side constitute a rectification side three-phase input terminal, and the transfer switches K11, K12, and K14 are closed and the transfer switch K13 is disconnected. When this is done, the first rectification side input terminal A11 and the second rectification side input terminal A12 are connected to form a rectification side single-phase input terminal together with the rectification side third input terminal A13, or when the transfer switch K11, the transfer switch K13, and the transfer switch K14 are closed and the transfer switch K12 is disconnected, the second rectification side input terminal A12 and the rectification side third input terminal A13 are connected to form a rectification side single-phase input terminal together with the rectification side first input terminal A11.

[0013] Furthermore, the rated current of the first input terminal A11 on the rectifier side = the rated current of the second input terminal A12 on the rectifier side = the rated current of the third input terminal A13 on the rectifier side, and the rated capacity of the rectifier side power tube bridge arm LBA11 = the rated capacity of the rectifier side power tube bridge arm LBA12 = the rated capacity of the rectifier side power tube bridge arm LBB11 = the rated capacity of the rectifier side power tube bridge arm LBB12 = the rated capacity of the rectifier side power tube bridge arm LBC11 = the rated capacity of the rectifier side power tube bridge arm LBC12.

[0014] The power supply further includes a rectifier-side power tube bridge arm LBA21, a rectifier-side power tube bridge arm LBB21, a rectifier-side power tube bridge arm LBB22, and a rectifier-side power tube bridge arm LBC21 connected in parallel between the positive DC bus BUS2+ and the negative DC bus BUS2-, The rectifier-side power tube bridge arm LBA21, the rectifier-side power tube bridge arm LBB21, the rectifier-side power tube bridge arm LBB22, and the rectifier-side power tube bridge arm LBC21 are provided with AC terminal points a21, b21, b22, and c21, respectively, and the AC terminal points a21, b21, b22, and c21 are connected to one end of the rectifier-side inductor INA21, the rectifier-side inductor INB21, the rectifier-side inductor INB22, and the rectifier-side inductor INC21, respectively. The other end of the rectifier-side inductor INA21 and the other end of the rectifier-side inductor INC21 are respectively the first input terminal A21 of the rectifier side and the third input terminal A23 of the rectifier side. The other end of the rectifier-side inductor INB21 is connected to one end of the transfer switch K22. The other end of the rectification-side inductor INB21 is connected to one end of the rectification-side inductor INB22, and the other end of the transfer switch K23 is connected to one end of the rectification-side inductor K21. The other end of the transfer switch K22 and the other end of the transfer switch K23 are connected to form the second input terminal A22 on the rectification side. The transfer switch K21 is connected in parallel between the other end of the rectification-side inductor INB21 that is connected opposite the rectification-side power tube bridge arm LBA21 and the other end of the rectification-side inductor INB21 that is connected opposite the rectification-side power tube bridge arm LBB21. The transfer switch K24 is connected in parallel between the other end of the rectification-side inductor INB22 that is connected opposite the rectification-side power tube bridge arm LBB22 and the other end of the rectification-side inductor INC21 that is connected opposite the rectification-side power tube bridge arm LBC21.

[0015] Furthermore, when the transfer switches K21 and K24 are turned off and the transfer switches K22 and K23 are turned on, the first rectification side input terminal A21, the second rectification side input terminal A22, and the third rectification side input terminal A23 constitute a rectification side three-phase input terminal, and the transfer switches K21, K22, and K24 are turned on and the transfer switch K23 is turned off. When this is done, the first rectifier side input terminal A21 and the second rectifier side input terminal A22 are connected to form a rectifier side single-phase input terminal together with the rectifier side third input terminal A23, or when the transfer switch K21, the transfer switch K23, and the transfer switch K24 are closed and the transfer switch K22 is disconnected, the second rectifier side input terminal A22 and the third rectifier side input terminal A23 are connected to form a rectifier side single-phase input terminal together with the rectifier side first input terminal A21.

[0016] Furthermore, the rated current of the first input terminal A21 on the rectifier side = the rated current of the second input terminal A22 on the rectifier side = the rated current of the third input terminal A23 on the rectifier side, and the rated capacity of the rectifier side power tube bridge arm LBA21 = twice the rated capacity of the rectifier side power tube bridge arm LBB21 = twice the rated capacity of the rectifier side power tube bridge arm LBB22 = the rated capacity of the rectifier side power tube bridge arm LBC21.

[0017] Furthermore, the rectifier-side power tube bridge arm may be an I-type three-level circuit, the rated line voltage of the rectifier-side three-phase input terminal may be preferably 3000V, and the rated voltage of the rectifier-side single-phase input terminal may be preferably 3000V.

[0018] Furthermore, the rated DC voltage between the positive DC bus and the negative DC bus does not exceed the DC withstand voltage of the power tube bridge arm, and is set to the maximum value on the premise that a sufficient safety margin is left.

[0019] The present invention also provides a high-speed train power supply transmission system including any of the AC-DC-AC traction converters described above. [Effects of the Invention]

[0020] Compared with the prior art, the beneficial effects of the AC-DC-AC traction converter according to the present invention are as follows: 1. Supports both three-phase and single-phase AC input, providing a wide range of applications. Moreover, there is no need to add a single-phase input terminal in addition to the three-phase input terminal, simplifying wiring. 2. The system can always maintain three-phase balance, ensuring safe, stable and economical operation of the train power supply system. 3. By using the AC-DC-AC traction converter of the present invention in a train traction transmission power supply system (also known as a high-speed train power supply transmission system), the train traction transmission power supply system can be applied to both a three-phase traction power supply system and a single-phase traction power supply system, which has a wide range of application and a flexible power supply method. 4. The AC-DC-AC traction converter according to the present invention can be used not only in mainline railways, but also in urban railroads and city railways. Other features and advantages of the present invention are described in detail in the detailed description section that follows. [Brief explanation of the drawings]

[0021] The accompanying drawings are used to provide a further understanding of embodiments of the present invention, constitute a part of the specification, and together with the following detailed description are used to explain, but not to limit, embodiments of the present invention. [Figure 1] 1 is a schematic diagram of a single-phase to three-phase compatible AC-DC-AC traction converter shown in one exemplary embodiment. [Figure 2] FIG. 1 is a schematic diagram of another single-phase to three-phase compatible AC-DC-AC traction converter shown in one illustrative embodiment. [Figure 3] FIG. 1 is a schematic diagram of a train traction transmission power supply system structure and wiring shown in one exemplary embodiment. [Figure 4]FIG. 1 is a schematic diagram of another train traction transmission power supply system structure and wiring shown in one exemplary embodiment. [Figure 5] 4 is a flow chart of the control of an AC-DC-AC traction converter according to one exemplary embodiment. [Figure 6] 10 is a flow chart of another AC-DC-AC traction converter control shown in one exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] In order to make the technical aspects of the present invention more readily understandable to those skilled in the art, the present invention will be further described below with reference to the drawings and specific embodiments.

[0023] Example 1 As shown in FIGS. 1 and 2, this embodiment provides a single-phase / three-phase compatible AC-DC-AC traction converter, which includes a plurality of rectifier-side power tube bridge arms and further includes three rectifier-side input terminals connected to corresponding rectifier-side power tube bridge arms by a rectifier-side inductor and a transfer switch. By changing the open / close state of the transfer switch, the rectifier side of the AC-DC-AC traction converter can accommodate both external three-phase power input and external single-phase power input. When external three-phase power input is used, the plurality of rectifier-side power tube bridge arms operate as a three-phase rectifier circuit, and when external single-phase power input is used, the plurality of rectifier-side power tube bridge arms operate as a single-phase rectifier circuit.

[0024] Here, the number of rectifier-side power tube bridge arms is determined according to the actual situation, and the switching devices of the power tube bridge arms are usually semiconductor switching devices, such as IGBTs. In specific implementation, each switching device may be provided with a diode or other circuit network connected in reverse parallel as necessary. Specifically, the number and types of switching devices can be designed according to the actual situation.

[0025] In the converter device of this embodiment, in the inverter-side power tube bridge arms (the inverter-side power tube bridge arms MBA1, MBB1, and MBC1 shown in FIG. 1 ), the inverter-side first output terminal B11 is drawn from the AC end point x1 of the inverter-side power tube bridge arm MBA1, the inverter-side second output terminal B12 is drawn from the AC end point y1 of the inverter-side power tube bridge arm MBB1, and the inverter-side third output terminal B13 is drawn from the AC end point z1 of the inverter-side power tube bridge arm MBC1. 2 , the inverter-side power tube bridge arm MBA2, the inverter-side power tube bridge arm MBB2, and the inverter-side power tube bridge arm MBC2 further include an inverter-side first output terminal B21 extending from the AC end point x2 of the inverter-side power tube bridge arm MBA2, an inverter-side second output terminal B22 extending from the AC end point y2 of the inverter-side power tube bridge arm MBB2, and an inverter-side third output terminal B23 extending from the AC end point z2 of the inverter-side power tube bridge arm MBC2. Furthermore, when implementing this embodiment, in the case of external three-phase power input, all of the rectifier-side power tube bridge arms can be controlled to operate, and there is no need to control specific or some of the power tube bridge arms to be disconnected. Similarly, in the case of external single-phase power input, all of the rectifier-side power tube bridge arms can be controlled to operate, and there is no need to control specific or some of the power tube bridge arms to be disconnected. In these two cases, switching only requires changing the open / close state of the corresponding transfer switch, thereby avoiding the complicated control of the converter caused by controlling the corresponding rectifier side power tube bridge arm to close or disconnect, and is easy to operate, safe and reliable.

[0026] Preferably, in the case of external three-phase power input, the plurality of rectifier-side power tube bridge arms operate in a three-phase rectifier circuit and have the same current capacity. In the case of external single-phase power input, the plurality of rectifier-side power tube bridge arms operate in a single-phase rectifier circuit and have the same current capacity.

[0027] Here, the current capacity of each rectifier side power tube bridge arm is the same means that the utilization rate of each rectifier side power tube bridge arm is made the same by controlling the power electronic device. That is, in actual operation, by controlling the power electronic device, each rectifier side power tube bridge arm operates at full load simultaneously or has the same actual utilization rate, thereby avoiding wasting the capacity of the power electronic device.

[0028] In the configuration shown in Figure 2, if the rated current of the rectifier side power tube bridge arm LBA21 = twice the rated current of the rectifier side power tube bridge arm LBB21 = twice the rated current of the rectifier side power tube bridge arm LBB22 = the rated current of the rectifier side power tube bridge arm LBC21 = I1, In the case of external three-phase power input, the rectifier-side power tube bridge arm LBA21, the rectifier-side power tube bridge arm LBB21, the rectifier-side power tube bridge arm LBB22, and the rectifier-side power tube bridge arm LBC21 jointly constitute the three-phase rectifier circuit on the rectifier side. In this case, when the actual current of the first input terminal A21 on the rectifier side = the actual current of the second input terminal A22 on the rectifier side = the actual current of the third input terminal A23 on the rectifier side = I2, the actual current of the rectifier-side power tube bridge arm LBA21 = I2, the actual current of the rectifier-side power tube bridge arm LBB21 = the actual current of the rectifier-side power tube bridge arm LBB22 = I2 / 2, and the actual utilization capacity of the rectifier-side power tube bridge arm LBC21 = I2 are controlled. At this time, when I2 = I1, each rectifier-side power tube bridge arm operates at full load simultaneously. When I1 < I2, the actual utilization rates of the rectifier-side power tube bridge arms are the same.

[0029] In the case of external single-phase power input, the rectifier-side power tube bridge arm LBA21, the rectifier-side power tube bridge arm LBB21, the rectifier-side power tube bridge arm LBB22, and the rectifier-side power tube bridge arm LBC21 jointly constitute the single-phase rectifier circuit on the rectifier side. At this time, when the actual current of the first input terminal A21 on the rectifier side = the actual current of the second input terminal A22 on the rectifier side = the actual current of the third input terminal A23 on the rectifier side = I3, the actual current of the rectifier-side power tube bridge arm LBA21 = 2 / 3I3, the actual current of the rectifier-side power tube bridge arm LBB21 = the actual current of the rectifier-side power tube bridge arm LBB22 = I3 / 3, and the actual utilization capacity of the rectifier-side power tube bridge arm LBC21 = 2 / 3I3 are controlled. At this time, when I3 = 3 / 2I1, each rectifier-side power tube bridge arm operates at full load simultaneously. When I3 < 3 / 2I1, the actual utilization rates of each rectifier-side power tube bridge arm are the same.

[0030] The same control method is also applied to the configuration shown in Figure 1. Other combinations of the number of bridge arms and capacitance parameter settings that can be thought of by a person skilled in the art based on the idea of ​​the present invention also belong to the subject matter protected by the present invention.

[0031] Preferably, as shown in FIG. 1 , this embodiment may include a rectifier-side power tube bridge arm LBA11, a rectifier-side power tube bridge arm LBA12, a rectifier-side power tube bridge arm LBB11, a rectifier-side power tube bridge arm LBB12, a rectifier-side power tube bridge arm LBC11, and a rectifier-side power tube bridge arm LBC12, which are connected in parallel between the positive DC bus BUS1+ and the negative DC bus BUS1-; The rectifier side power tube bridge arm LBA11, the rectifier side power tube bridge arm LBA12, the rectifier side power tube bridge arm LBB11, the rectifier side power tube bridge arm LBB12, the rectifier side power tube bridge arm LBC11, and the rectifier side power tube bridge arm LBC12 are provided with AC terminal points a11, a12, b11, b12, c11, and c12, respectively. The AC terminal point a12, the AC terminal point b11, the AC terminal point b12, the AC terminal point c11, and the AC terminal point c12 are connected to one end of the rectifier side inductor INA11, the rectifier side inductor INA12, the rectifier side inductor INB11, the rectifier side inductor INB12, the rectifier side inductor INC11, and the rectifier side inductor INC12, respectively. The other ends of the rectifier side inductor INA11 and the rectifier side inductor INA12 are connected to form the first input terminal A11 of the rectifier side. The other end of the rectifier-side inductor INC12 is connected to one end of a transfer switch K12, the other end of the rectifier-side inductor INB11 is connected to one end of a transfer switch K13, and the other ends of the transfer switches K12 and K13 are connected to the second input terminal A12 on the rectifier side. A transfer switch K11 is connected in parallel between the other end of the rectifier-side inductor INA12 connected opposite the rectifier-side power tube bridge arm LBA12 and the other end of the rectifier-side inductor INB11 connected opposite the rectifier-side power tube bridge arm LBB11. A transfer switch K14 is connected in parallel between the other end of the rectifier-side inductor INB12 connected opposite the rectifier-side power tube bridge arm LBB12 and the other end of the rectifier-side inductor INC11 connected opposite the rectifier-side power tube bridge arm LBC11. Here, in this embodiment, a bus capacitor BUSC1 may be further included, connected in parallel between the positive DC bus BUS1+ and the negative DC bus BUS1-.

[0032] Specifically, when the transfer switches K11 and K14 are disconnected and the transfer switches K12 and K13 are closed, the first rectification side input terminal A11, the second rectification side input terminal A12, and the third rectification side input terminal A13 constitute a rectification side three-phase input terminal, and the transfer switches K11, K12, and K14 are closed and the transfer switch K13 is turned off. When the transfer switch K11, the transfer switch K13, and the transfer switch K14 are closed and the transfer switch K12 is disconnected, the first rectification side input terminal A11 and the second rectification side input terminal A12 are connected to form a rectification side single-phase input terminal together with the rectification side third input terminal A13, or when the transfer switch K11, the transfer switch K13, and the transfer switch K14 are closed and the transfer switch K12 is disconnected, the second rectification side input terminal A12 and the third rectification side input terminal A13 are connected to form a rectification side single-phase input terminal together with the rectification side first input terminal A11.

[0033] Specifically, the rated current of the first rectifier input terminal A11 = the rated current of the second rectifier input terminal A12 = the rated current of the third rectifier input terminal A13, the rated capacity of the rectifier power tube bridge arm LBA11 = the rated capacity of the rectifier power tube bridge arm LBA12 = the rated capacity of the rectifier power tube bridge arm LBB11 = the rated capacity of the rectifier power tube bridge arm LBB12 = the rated capacity of the rectifier power tube bridge arm LBC11 = the rated capacity of the rectifier power tube bridge arm LBC12. Setting these rated capacities optimizes the capacity utilization of the AC-DC-AC converter device including the six rectifier power tube bridge arms.

[0034] Preferably, as shown in FIG. 2 , this embodiment may include a rectifier-side power tube bridge arm LBA21, a rectifier-side power tube bridge arm LBB21, a rectifier-side power tube bridge arm LBB22, and a rectifier-side power tube bridge arm LBC21 connected in parallel between the positive DC bus BUS2+ and the negative DC bus BUS2−; The rectifier-side power tube bridge arm LBA21, the rectifier-side power tube bridge arm LBB21, the rectifier-side power tube bridge arm LBB22, and the rectifier-side power tube bridge arm LBC21 are respectively provided with AC terminal points a21, b21, b22, and c21. The AC terminal points a21, b21, b22, and c21 are respectively connected to one end of the rectifier-side inductor INA21, the rectifier-side inductor INB21, the rectifier-side inductor INB22, and the rectifier-side inductor INC21. The other end of the rectifier-side inductor INA21 and the other end of the rectifier-side inductor INC21 are respectively the first rectifier-side input terminal A21 and the third rectifier-side input terminal A23. The other end of the rectifier-side inductor INB21 is connected to one end of the transfer switch K22. The other end of the rectifier-side inductor INB22 is connected to one end of a transfer switch K23, and the other end of the transfer switch K22 and the other end of the transfer switch K23 are connected to form a second rectifier-side input terminal A22. A transfer switch K21 is connected in parallel between the other end of the rectifier-side inductor INA21 connected opposite the rectifier-side power tube bridge arm LBA21 and the other end of the rectifier-side inductor INB21 connected opposite the rectifier-side power tube bridge arm LBB21. A transfer switch K24 is connected in parallel between the other end of the rectifier-side inductor INB22 connected opposite the rectifier-side power tube bridge arm LBB22 and the other end of the rectifier-side inductor INC21 connected opposite the rectifier-side power tube bridge arm LBC21. Here, this embodiment may further include a bus capacitor BUSC2 connected in parallel between the positive DC bus BUS2+ and the negative DC bus BUS2-.

[0035] Specifically, when the transfer switches K21 and K24 are disconnected and the transfer switches K22 and K23 are closed, the first rectification side input terminal A21, the second rectification side input terminal A22, and the third rectification side input terminal A23 constitute a rectification side three-phase input terminal, and the transfer switches K21, K22, and K24 are closed and the transfer switch K23 is turned off. When the transfer switch K21, the transfer switch K23, and the transfer switch K24 are closed and the transfer switch K22 is disconnected, the first rectification side input terminal A21 and the second rectification side input terminal A22 are connected to form a rectification side single-phase input terminal together with the rectification side third input terminal A23, or when the transfer switch K21, the transfer switch K23, and the transfer switch K24 are closed and the transfer switch K22 is disconnected, the second rectification side input terminal A22 and the third rectification side input terminal A23 are connected to form a rectification side single-phase input terminal together with the rectification side first input terminal A21.

[0036] Specifically, the rated current of the first rectifier input terminal A21 = the rated current of the second rectifier input terminal A22 = the rated current of the third rectifier input terminal A23, the rated capacity of the rectifier power tube bridge arm LBA21 = twice the rated capacity of the rectifier power tube bridge arm LBB21 = twice the rated capacity of the rectifier power tube bridge arm LBB22 = the rated capacity of the rectifier power tube bridge arm LBC21. Setting the rated capacities in this way makes it possible to optimize the capacity utilization of the AC-DC-AC converter device including four rectifier power tube bridge arms.

[0037] In this embodiment, the rated line voltage of the rectifier-side three-phase input terminals may be 3000V, and the rated voltage of the rectifier-side single-phase input terminals may be 3000V. The rectifier-side power tube bridge arm may be an I-type three-level circuit. The use of an I-type three-level circuit allows for use in a three-phase power supply transmission system, while increasing the converter voltage level to meet the 3000V input voltage requirement. This is the optimal circuit means to be selected depending on the input voltage level of 3000V.

[0038] In this embodiment, the rated DC voltage between the positive DC bus and the negative DC bus is set to the maximum value on the premise that it does not exceed the DC withstand voltage of the power tube bridge arm and leaves a sufficient safety margin.

[0039] For a better understanding of the present invention, as shown in Figures 3 and 4, the single-phase to three-phase AC-DC-AC converter device according to this embodiment can be applied to a high-speed train power supply transmission system corresponding to single phase and three phase (see another patent application entitled "High-speed train power supply transmission system, AC-DC-AC traction converter, and control method thereof" with publication number CN113799663A filed on the same filing date as the present invention).

[0040] For example, when an AC-DC-AC converter device including six rectifier-side power tube bridge arms as shown in Figure 1 is applied to a high-speed train power supply transmission system that supports single-phase and three-phase power supply (see Figure 3 or Figure 4), the control method flow can be seen in Figure 5. Here, determining the needs of the application scenario specifically means determining whether the target operating mode of the high-speed train power supply transmission system is a single-phase power supply transmission mode or a three-phase power supply transmission mode. Furthermore, the three rectifier-side input terminals (rectifier-side first input terminal A11, rectifier-side second input terminal A12, and rectifier-side third input terminal A13) are configured as three-phase input terminals or single-phase input terminals by operating transfer switches K11, K12, K13, and K14 according to the application scenario.

[0041] Specifically, in the wiring configuration shown in FIG. 3 (the first input terminal A11 on the rectification side is connected to the power feed cable LA via a feedout cable LNA1 and a feedout switch KQA1, the second input terminal A12 on the rectification side is connected to the power feed cable LB via a feedout cable LNB1 and a feedout switch KQB1, and the third input terminal A13 on the rectification side is connected to the power feed cable LC via a feedout cable LNC1 and a feedout switch KQC1, and the power feed cables LA, LB, and LC are respectively connected to the power feed bus MA and the power feed bus LB. The power supply bus MA is connected to the power supply bus MB and the power supply bus MC, and a transfer switch K is connected in parallel between the power supply bus MA and the power supply bus MB. The target operating mode of the high-speed train power supply transmission system can be determined by determining whether the transfer switch K is closed. If the transfer switch K is closed, the target operating mode of the high-speed train power supply transmission system is the three-phase power supply transmission mode, in which case the transfer switches K11 and K14 need to be closed and the transfer switches K12 and K13 need to be closed. If the transfer switch K is closed, the target operating mode of the high-speed train power supply transmission system is the single-phase power supply transmission mode, in which case the transfer switches K11, K12, and K14 need to be closed and the transfer switch K13 needs to be closed. Note that the operation of connecting the second rectifier-side input terminal A12 and the third rectifier-side input terminal A13 by closing transfer switches K11, K13, and K14 and disconnecting transfer switch K12 to form the first rectifier-side input terminal A11 and the rectifier-side single-phase input terminal can be applied to the wiring configuration shown in Figure 4, in which the first rectifier-side input terminal A11 is electrically connected to the power feed cable LC, the second input terminal A12 is electrically connected to the power feed cable LB, and the third input terminal A13 is electrically connected to the power feed cable LA, and other connection relationships are as shown. Other applicable connection relationships will not be further described here, as those skilled in the art can adjust them according to actual situations.Also shown in Figures 3 and 4 are current collector CA, current collector CB, current collector CC, current collecting cable LA0, current collecting cable LB0, current collecting cable LC0, current collecting switch KLA, current collecting switch KLB, current collecting switch KLC, voltage transformer PTAB, voltage transformer PTBC, voltage transformer PTCA, and measurement controller CTL.

[0042] In the form of an AC-DC-AC converter device including four rectifier-side power tube bridge arms as shown in FIG. 2, those skilled in the art can refer to the above description for how to apply it to a high-speed train power supply transmission system corresponding to single-phase and three-phase, and can refer to FIG. 6 for the control method, and the specific wiring relationship and corresponding operation method will not be further described.

[0043] Example 2 A second embodiment of the present invention provides a high-speed train power supply transmission system including the single-phase / three-phase compatible AC-DC-AC traction converter of the first embodiment. The high-speed train power supply transmission system of the second embodiment of the present invention is applicable to both three-phase traction power supply systems and single-phase traction power supply systems, and has a wide range of application and a flexible power supply method.

[0044] The above is merely a preferred embodiment of the present invention, and the above preferred embodiment should not be considered as a limitation on the present invention, and the protection scope of the present invention is in accordance with the scope defined in the claims. Those skilled in the art may make some improvements and modifications without departing from the spirit and scope of the present invention, and these improvements and modifications shall also be considered as the protection scope of the present invention. [Explanation of symbols]

[0045] A11, A21 First input terminal on the rectifier side A12, A22 Second input terminal on the rectifier side A13, A23 Third input terminal on the rectifier side a11,a12,a21 AC end point b11,b12,b21,b22 AC end point c11,c12,c21 AC end point B11, B21 Inverter side first output terminal B12, B22 Inverter side second output terminal B13, B23 Inverter side third output terminal BUS1+, BUS2+ Positive DC bus BUS1-, BUS2- Negative DC bus BUSC1, BUSC2 bus capacitors INA11, INA12, INA21 Rectification side inductor INB11, INB12, INB21, INB22 Rectification side inductors INC11, INC12, INC21 Rectification side inductors K11, K12, K13, K14, K21, K22, K23, K24 Transfer switch LBA11, LBA12, LBA21 Rectifier side power tube bridge arm LBB11, LBB12, LBB21, LBB22 Rectifier side power tube bridge arm LBC11, LBC12, LBC21 Rectifier side power tube bridge arm MBA1,MBA2 inverter side power tube bridge arm MBB1, MBB2 inverter side power tube bridge arm MBC1,MBC2 inverter side power tube bridge arm x1,x2 AC end point y1,y2 AC end point z1,z2 AC end point

Claims

1. 1. A single-phase / three-phase compatible AC-DC-AC traction converter, comprising: The AC-DC-AC traction converter includes a plurality of rectifier-side power tube bridge arms, and further includes three rectifier-side input terminals connected to corresponding rectifier-side power tube bridge arms by rectifier-side inductors and transfer switches, and the rectifier side of the AC-DC-AC traction converter can accommodate both external three-phase power input and single-phase power input by changing the open / close state of the transfer switches; When an external three-phase power is input, the plurality of rectifier-side power tube bridge arms operate as a three-phase rectifier circuit; When an external single-phase power is input, the plurality of rectifier-side power tube bridge arms operate as a single-phase rectifier circuit; The power supply further includes a rectifier-side power tube bridge arm LBA11, a rectifier-side power tube bridge arm LBA12, a rectifier-side power tube bridge arm LBB11, a rectifier-side power tube bridge arm LBB12, a rectifier-side power tube bridge arm LBC11, and a rectifier-side power tube bridge arm LBC12, which are connected in parallel between the positive DC bus BUS1+ and the negative DC bus BUS1-; The rectifier side power tube bridge arm LBA11, the rectifier side power tube bridge arm LBA12, the rectifier side power tube bridge arm LBB11, the rectifier side power tube bridge arm LBB12, the rectifier side power tube bridge arm LBC11, and the rectifier side power tube bridge arm LBC12 are provided with AC terminal points a11, a12, b11, b12, c11, and c12, respectively. The terminal point b11, the AC terminal point b12, the AC terminal point c11, and the AC terminal point c12 are connected to one end of the rectifier side inductor INA11, the rectifier side inductor INA12, the rectifier side inductor INB11, the rectifier side inductor INB12, the rectifier side inductor INC11, and the rectifier side inductor INC12, respectively. The other ends of the rectifier side inductor INA11 and the rectifier side inductor INA12 are connected to form a first input terminal A11 on the rectifier side. The other ends of the rectifier side inductor INC11 and the rectifier side inductor INC12 are connected to form a first input terminal A11 on the rectifier side. The other end of the rectifier-side inductor INB11 is connected to one end of the transfer switch K12, and the other end of the rectifier-side inductor INB12 is connected to one end of the transfer switch K13. The other end of the transfer switch K12 and the other end of the transfer switch K13 are connected to form the rectifier-side second input terminal A12. The other end of the rectifier-side inductor INB12, which is connected opposite to the rectifier-side power tube bridge arm LBA12, and the other end of the rectifier-side inductor INB11 are connected to one end of the transfer switch K13. a transfer switch K11 is connected in parallel between the other end of the rectification-side inductor INB12 connected to face the rectification-side power tube bridge arm LBB12 and the other end of the rectification-side inductor INC11 connected to face the rectification-side power tube bridge arm LBC11, and a transfer switch K14 is connected in parallel between the other end of the rectification-side inductor INB12 connected to face the rectification-side power tube bridge arm LBB12 and the other end of the rectification-side inductor INC11 connected to face the rectification-side power tube bridge arm LBC11.

2. A single-phase / three-phase compatible AC-DC-AC traction converter, The AC-DC-AC traction converter includes a plurality of rectifier-side power tube bridge arms, and further includes three rectifier-side input terminals connected to corresponding rectifier-side power tube bridge arms by rectifier-side inductors and transfer switches, and the rectifier side of the AC-DC-AC traction converter can accommodate both external three-phase power input and single-phase power input by changing the open / close state of the transfer switches; When an external three-phase power is input, the plurality of rectifier-side power tube bridge arms operate as a three-phase rectifier circuit; When an external single-phase power is input, the plurality of rectifier-side power tube bridge arms operate as a single-phase rectifier circuit; the power supply further includes a rectifier-side power tube bridge arm LBA21, a rectifier-side power tube bridge arm LBB21, a rectifier-side power tube bridge arm LBB22, and a rectifier-side power tube bridge arm LBC21 connected in parallel between the positive DC bus BUS2+ and the negative DC bus BUS2-; The rectifier-side power tube bridge arm LBA21, the rectifier-side power tube bridge arm LBB21, the rectifier-side power tube bridge arm LBB22, and the rectifier-side power tube bridge arm LBC21 are provided with AC terminal points a21, b21, b22, and c21, respectively. The AC terminal points a21, b21, b22, and c21 are connected to one end of the rectifier-side inductor INA21, the rectifier-side inductor INB21, the rectifier-side inductor INB22, and the rectifier-side inductor INC21, respectively. The other end of the rectifier-side inductor INA21 and the other end of the rectifier-side inductor INC21 are the rectifier-side first input terminal A21 and the rectifier-side third input terminal A23, respectively. The other end of the rectifier-side inductor INB21 is connected to one end of the transfer switch K22. the other end of the transfer switch K22 is connected to one end of a transfer switch K23, and the other end of the transfer switch K22 and the other end of the transfer switch K23 are connected to form a second input terminal A22 on the rectification side; the transfer switch K21 is connected in parallel between the other end of the rectification-side inductor INA21 that is connected opposite the rectification-side power tube bridge arm LBA21 and the other end of the rectification-side inductor INB21 that is connected opposite the rectification-side power tube bridge arm LBB21; and the transfer switch K24 is connected in parallel between the other end of the rectification-side inductor INB22 that is connected opposite the rectification-side power tube bridge arm LBB22 and the other end of the rectification-side inductor INC21 that is connected opposite the rectification-side power tube bridge arm LBC21.

3. When external three-phase power is input, the plurality of rectifier-side power tube bridge arms operate in a three-phase rectifier circuit, and the current capacity of each rectifier-side power tube bridge arm is the same; 3. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 1, wherein, in the case of an external single-phase power input, the plurality of rectifier-side power tube bridge arms operate as a single-phase rectifier circuit, and the current capabilities of each rectifier-side power tube bridge arm are the same.

4. When the transfer switches K11 and K14 are disconnected and the transfer switches K12 and K13 are closed, the first rectification side input terminal A11, the second rectification side input terminal A12, and the third rectification side input terminal A13 constitute rectification side three-phase input terminals, When the transfer switches K11, K12, and K14 are closed and the transfer switch K13 is disconnected, the first rectification side input terminal A11 and the second rectification side input terminal A12 are connected to form a rectification side single-phase input terminal together with the third rectification side input terminal A13, or 2. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 1, wherein when the transfer switch K11, the transfer switch K13, and the transfer switch K14 are closed and the transfer switch K12 is disconnected, the second rectification-side input terminal A12 and the third rectification-side input terminal A13 are connected to form a rectification-side single-phase input terminal with the first rectification-side input terminal A11.

5. 2. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 1, wherein the rated current of the first rectifier side input terminal A11 = the rated current of the second rectifier side input terminal A12 = the rated current of the third rectifier side input terminal A13, and the rated capacity of the rectifier side power tube bridge arm LBA11 = the rated capacity of the rectifier side power tube bridge arm LBA12 = the rated capacity of the rectifier side power tube bridge arm LBB11 = the rated capacity of the rectifier side power tube bridge arm LBB12 = the rated capacity of the rectifier side power tube bridge arm LBC11 = the rated capacity of the rectifier side power tube bridge arm LBC12.

6. When the transfer switches K21 and K24 are disconnected and the transfer switches K22 and K23 are closed, the first rectification side input terminal A21, the second rectification side input terminal A22, and the third rectification side input terminal A23 constitute rectification side three-phase input terminals, When the transfer switch K21, the transfer switch K22, and the transfer switch K24 are closed and the transfer switch K23 is disconnected, the first rectification side input terminal A21 and the second rectification side input terminal A22 are connected to form a rectification side single-phase input terminal together with the third rectification side input terminal A23, or 3. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 2, wherein when the transfer switch K21, the transfer switch K23, and the transfer switch K24 are closed and the transfer switch K22 is disconnected, the second rectification-side input terminal A22 and the third rectification-side input terminal A23 are connected to form a rectification-side single-phase input terminal with the first rectification-side input terminal A21.

7. 3. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 2, wherein the rated current of the first input terminal A21 on the rectifier side = the rated current of the second input terminal A22 on the rectifier side = the rated current of the third input terminal A23 on the rectifier side, and the rated capacity of the rectifier side power tube bridge arm LBA21 = twice the rated capacity of the rectifier side power tube bridge arm LBB21 = twice the rated capacity of the rectifier side power tube bridge arm LBB22 = the rated capacity of the rectifier side power tube bridge arm LBC21.

8. 7. The single-phase / three-phase compatible AC-DC-AC traction converter according to claim 4 or 6, wherein the rectifier side power tube bridge arm is an I-type three-level circuit.

9. The single-phase and three-phase compatible AC-DC-AC traction converter as claimed in claim 8, wherein the rated DC voltage between the positive DC bus and the negative DC bus does not exceed the DC withstand voltage of the power tube bridge arm and is set to the highest value while leaving a sufficient safety margin.

10. A high-speed train power supply and transmission system comprising the single-phase / three-phase compatible AC-DC-AC traction converter according to claim 1.

11. A high-speed train power supply transmission system comprising the single-phase / three-phase compatible AC-DC-AC traction converter described in claim 2.

Images