Energy storage embedded railway power regulator

Abstract

The utility model discloses an energy storage embedded railway power regulator which comprises an energy storage battery, a coupling transformer and a half-bridge converter module. The half-bridge converter module comprises a pair of four-switch bridge arms formed by connecting four power electronic switches in series and an intermediate direct current link formed by connecting two capacitors in series, and the two four-switch bridge arms are connected with the intermediate direct current link to form a half-bridge back-to-back structure. The primary side of the coupling transformer is connected with a traction feeder, the secondary side common end is connected with the midpoint of the intermediate DC link, and the secondary side non-common end is connected with the midpoint of the four-switch bridge arm through an inductor. Positive electrodes of the alpha-side energy storage battery and the beta-side energy storage battery are connected with Ualpha and Ubeta points in the four-switch bridge arm, and negative electrodes of the alpha-side energy storage battery and the beta-side energy storage battery are connected with D alpha and D beta points in the four-switch bridge arm. According to the utility model, the energy storage battery is directly embedded into the railway power regulator without an extra DC / DC converter, power interaction between two traction feeders, between the alpha-side energy storage battery and the beta-phase traction feeder and between the beta-side energy storage battery and the alpha-phase traction feeder can be realized, and the structure is simpler and more compact.

Description

Technical Field

[0001] The present invention relates to the field of traction power supply for electrified railways, and particularly to a storage embedded type railway power conditioner. Background Art

[0002] Electrified railways have become an indispensable part of China's modern transportation system. In particular, high-speed electrified railways, with their characteristics of safety, reliability, high speed, large passenger capacity, and significant environmental protection and energy conservation, not only greatly improve transportation efficiency but also promote national economic development. However, while the rapid development of high-speed electrified railways has developed the economy and facilitated people's travel, it has brought problems of power quality and energy consumption to the power grid and traction power supply system.

[0003] Currently, high-speed electrified railways mainly have two problems: negative sequence governance of power quality and utilization of regenerative braking energy. At present, scholars at home and abroad have conducted a large number of studies on negative sequence governance. The main methods of negative sequence governance include static var compensator, static synchronous compensator, railway power conditioner, etc. Usually, a railway power conditioner is used to solve the problems of negative sequence, harmonic current, and reactive power compensation in the traction power supply system. For the problem of regenerative braking energy utilization, methods such as direct utilization, feedback utilization, and energy storage utilization are mainly used. Direct utilization has the advantages of high energy utilization rate and low cost, but the regenerative braking energy can only be used by the multiple units on the same power supply arm, and the flexibility is poor. Although feedback utilization is environmentally friendly, energy-saving, and has good economic benefits, the impact caused by directly feeding a large amount of regenerative braking energy back to the power grid is greater. Energy storage utilization not only has high flexibility but also has a high energy utilization rate. Through energy storage devices, regenerative braking energy can be stored for subsequent use, thereby improving the energy utilization rate. A railway power conditioner can realize power transfer between two traction feeders. A storage type power conditioner can not only solve the problems of negative sequence, harmonic current, and reactive power compensation in the traction power supply system but also reasonably utilize regenerative braking energy. Considering the power interaction between the energy storage battery and the traction feeder, each set of energy storage batteries requires a set of bidirectional DC / DC converters to be connected to the intermediate DC link. However, obviously, setting a set of bidirectional DC / DC converters for each set of energy storage batteries not only has a high cost but also the system structure is not compact enough, which is not conducive to system integration and unified control. Summary of the Invention

[0004] The purpose of the present utility model is to solve the problems of the storage type railway power conditioner, such as having too many DC / DC converters, the system structure not being compact enough, and not being conducive to system integration and unified control. The present utility model directly embeds the energy storage battery into the railway power conditioner without additional DC / DC converters, making the system structure more compact. The present utility model can be applied to a multi-level structure through series and parallel connections to expand the capacity, with more flexible control, lower cost, and more efficient operation.

[0005] The technical solution of the present utility model is a storage embedded type railway power regulator, which is characterized in that: the storage embedded type railway power regulator includes a storage battery, a coupling transformer, and a half-bridge converter module.

[0006] The half-bridge converter module includes a pair of four-switch arms formed by four power electronic switches in series and an intermediate DC link formed by two capacitors in series. The two four-switch arms are connected to the intermediate DC link to form a half-bridge back-to-back structure, and the coupling transformers CT α 、CT β The primary sides are respectively connected to the α and β phase traction feeders, the common terminal of the secondary side is connected to the midpoint O of the intermediate DC link, and the non-common terminals of the secondary side respectively pass through the third inductor L α 、the fourth inductor L β and are connected to the midpoints M α 、M β of the α and β side four-switch arms.

[0007] In the described storage embedded type railway power regulator, the storage embedded type railway power regulator includes an α-side four-switch arm formed by series connection of a first switch S α1 、a second switch S α2 、a third switch S α3 、a fourth switch S α4 and a β-side four-switch arm formed by series connection of a fifth switch S β1 、a sixth switch S β2 、a seventh switch S β3 、an eighth switch S β4 . The collector of the first switch S α1 is connected to the P point of the intermediate DC link, the emitter of the first switch S α1 is connected to the collector of the second switch S α2 , and the connection point is U α . The emitter of the second switch S α2 is connected to the collector of the third switch S α3 , and the connection point is M α . The emitter of the third switch S α3 is connected to the collector of the fourth switch S α4 , and the connection point is D α . The emitter of the fourth switch S α4 is connected to the N point of the intermediate DC link. The collector of the fifth switch S β1 is connected to the P point of the intermediate DC link, the emitter of the fifth switch S β1 is connected to the collector of the sixth switch S β2 , and the connection point is U β . The emitter of the sixth switch S β2 is connected to the collector of the seventh switch S β3 , and the connection point is M β。The seventh switch S β3 The emitter is connected to the eighth switch S β4 The collector, and the connection point is D β , the eighth switch S β4 The emitter is connected to the N point of the intermediate DC link.

[0008] In the energy storage embedded railway power regulator described above, the energy storage battery B α The positive electrode is connected to one end of the first inductor L Bα The other end of the first inductor L Bα Is connected to the U point of the α-side four-switch bridge arm α The energy storage battery B α The negative electrode is connected to the D point of the α-side four-switch bridge arm α The energy storage battery B β The positive electrode is connected to one end of the second inductor L Bβ The other end of the second inductor L Bβ Is connected to the U point of the β-side four-switch bridge arm β The energy storage battery B β The negative electrode is connected to the D point of the β-side four-switch bridge arm β Point.

[0009] In the energy storage embedded railway power regulator described above, the first capacitor C u And the second capacitor C d Are connected in series to form the intermediate DC link, and the connection point is the O point. The O point is connected to the common terminal of the secondary sides of the coupling transformers CT α 、CT β Connected.

[0010] In the energy storage embedded railway power regulator described above, the α side of the railway power regulator is connected to the third inductor L through the M α Point and one end of the third inductor L α The other end of the third inductor L α Is connected to the non-common terminal of the secondary side of the coupling transformer CT α , and the β side of the energy storage embedded railway power regulator is connected to the fourth inductor L through the M β Point and one end of the fourth inductor L β The other end of the fourth inductor L β Is connected to the non-common terminal of the secondary side of the coupling transformer CT β Connected.

[0011] In the energy storage embedded railway power regulator described above, the first switch S α1 、The second switch S α2 、The third switch S α3 、The fourth switch S α4 、The fifth switch S β1 、The sixth switch S β2 、The seventh switch S β3 、The eighth switch Sβ4 All eight switches are paralleled with freewheeling diodes.

[0012] The energy storage embedded type railway power regulator can be applied to a multi - plex structure through series and parallel connections to expand the capacity.

[0013] The energy storage embedded type railway power regulator has three working modes. Working mode 1 is the power transfer between the α - phase and β - phase traction feeders. Working mode 2 is the power interaction between the energy storage battery on the β - side and the α - phase traction feeder. Working mode 3 is the power interaction between the energy storage battery on the α - side and the β - phase traction feeder.

[0014] For the energy storage embedded type railway power regulator, in working mode 1, there is no power interaction between the energy storage and the traction power supply system, and the power is transferred between the α - phase and β - phase traction feeders.

[0015] For the energy storage embedded type railway power regulator, in working mode 2, the energy storage battery on the β - side and the α - phase traction feeder have power interaction. When the α - phase traction feeder is in the regenerative braking state, the recovered braking energy charges the energy storage battery on the β - side. When the α - phase traction feeder is in the traction state and the energy storage battery has sufficient power, the energy storage battery on the β - side delivers traction power to the α - phase traction feeder.

[0016] For the energy storage embedded type railway power regulator, in working mode 3, the energy storage battery on the α - side and the β - phase traction feeder have power interaction. When the β - phase traction feeder is in the regenerative braking state, the recovered braking energy charges the energy storage battery on the α - side. When the β - phase traction feeder is in the traction state and the energy storage battery has sufficient power, the energy storage battery on the α - side delivers traction power to the β - phase traction feeder.

[0017] The energy storage embedded type railway power regulator does not require an additional DC / DC circuit. The energy storage battery is directly embedded in the four - switch bridge arm, and together with the half - bridge back - to - back structure, it realizes the power interaction between the two traction feeders, between the energy storage battery on the α - side and the β - phase traction feeder, and between the energy storage battery on the β - side and the α - phase traction feeder. Compared with the topology structure in which the energy storage module is connected to the intermediate DC link of the railway power regulator through a DC / DC bidirectional converter, especially when applied to a multi - plex structure to expand the capacity, the structure of the present utility model is simpler and more compact, and the control is more flexible. Brief Description of the Drawings

[0018] By referring to the attached drawings, the features and advantages of the present utility model can be more clearly understood. The attached drawings should not be construed as any limitation to the present utility model.

[0019] Figure 1 : Block diagram of an energy storage embedded type railway power regulator provided by the present utility model.

[0020] Figure 2 : Simplified circuit diagram of the present utility model.

[0021] Figure 3 : Circuit diagram of working mode 1.

[0022] Figure 4 : Circuit diagram of process 1 of the power input mode of the half-bridge converter module in working mode 1.

[0023] Figure 5 : Circuit diagram of process 2 of the power input mode of the half-bridge converter module in working mode 1.

[0024] Figure 6 : Circuit diagram of process 1 of the power output mode of the half-bridge converter module in working mode 1.

[0025] Figure 7 : Circuit diagram of process 2 of the power output mode of the half-bridge converter module in working mode 1.

[0026] Figure 8 : Circuit diagram of working mode 2.

[0027] Figure 9 : Circuit diagram of the short-circuit state of the boost converter mode in working mode 2.

[0028] Figure 10 : Circuit diagram of the freewheeling state of the boost converter mode in working mode 2.

[0029] Figure 11 : Circuit diagram of the short-circuit state of the buck converter mode in working mode 2.

[0030] Figure 12 : Circuit diagram of the freewheeling state of the buck converter mode in working mode 2.

[0031] Figure 13 : Circuit diagram of working mode 3.

[0032] Figure 14 : Circuit diagram of the short-circuit state of the boost converter mode in working mode 3.

[0033] Figure 15 : Circuit diagram of the freewheeling state of the boost converter mode in working mode 3.

[0034] Figure 16 : Circuit diagram of the short-circuit state of the buck converter mode in working mode 3.

[0035] Figure 17 : Circuit diagram of the freewheeling state of the buck converter mode in working mode 3. Specific implementation manner

[0036] For the convenience of those of ordinary skill in the art to understand and implement the present invention, the following further describes the present utility model invention in detail with reference to the accompanying drawings. It should be understood that the description herein is only for the purpose of explaining and illustrating the present invention and is not used to limit the present invention.

[0037] Figure 1 The circuit diagram of a storage embedded type railway power conditioner provided for the present utility model is as Figure 1 shown. A storage embedded type railway power conditioner includes a storage battery, a coupling transformer, and a half-bridge converter module.

[0038] The half-bridge converter module includes a pair of four-switch bridge arms formed by four power electronic switches connected in series and an intermediate DC link formed by two capacitors connected in series. The two four-switch bridge arms are connected to form a half-bridge back-to-back structure through connection with the intermediate DC link. The primary sides of the coupling transformers CT α 、CT β are respectively connected to the α and β phase traction feeders, the common terminal of the secondary side is connected to the midpoint O of the intermediate DC link, and the non-common terminals of the secondary side are respectively connected to the midpoints M α 、M β of the α and β side four-switch bridge arms through the third inductor L α 、the fourth inductor L β .

[0039] In the described storage embedded type railway power conditioner, the storage embedded type railway power conditioner includes an α side four-switch bridge arm formed by connecting the first switch S α1 、the second switch S α2 、the third switch S α3 、the fourth switch S α4 in series and a β side four-switch bridge arm formed by connecting the fifth switch S β1 、the sixth switch S β2 、the seventh switch S β3 、the eighth switch S β4 in series. The collector of the first switch S α1 is connected to the P point of the intermediate DC link, the emitter of the first switch S α1 is connected to the collector of the second switch S α2 , the connection point is U α , the emitter of the second switch S α2 is connected to the collector of the third switch S α3 , the connection point is M α , the emitter of the third switch S α3 is connected to the collector of the fourth switch S α4 , the connection point is D α , and the emitter of the fourth switch S α4 is connected to the N point of the intermediate DC link. The fifth switch S β1The collector is connected to point P of the intermediate DC link, and the fifth switch S β1 The emitter is connected to the sixth switch S β2 The collector, and the connection point is U β , and the sixth switch S β2 The emitter is connected to the seventh switch S β3 The collector, and the connection point is M β , and the seventh switch S β3 The emitter is connected to the eighth switch S β4 The collector, and the connection point is D β , and the eighth switch S β4 The emitter is connected to point N of the intermediate DC link.

[0040] In the energy storage embedded type railway power regulator described above, the energy storage battery B α The positive electrode is connected to one end of the first inductor L Bα , and the other end of the first inductor L Bα Is connected to point U of the α-side four-switch bridge arm α . The energy storage battery B α The negative electrode is connected to point D of the α-side four-switch bridge arm α . The energy storage battery B β The positive electrode is connected to one end of the second inductor L Bβ , and the other end of the second inductor L Bβ Is connected to point U of the β-side four-switch bridge arm β . The energy storage battery B β The negative electrode is connected to point D of the β-side four-switch bridge arm β .

[0041] In the energy storage embedded type railway power regulator described above, the first capacitor C u And the second capacitor C d Are connected in series to form the intermediate DC link, and the connection point is point O. Point O is connected to the common terminal of the secondary sides of the coupling transformers CT α , CT β .

[0042] In the energy storage embedded type railway power regulator described above, the α side of the railway power regulator is connected to the third inductor L α One end through point M α , and the other end of the third inductor L α Is connected to the non-common terminal of the secondary side of the coupling transformer CT α . The β side of the energy storage embedded type railway power regulator is connected to the fourth inductor L β One end through point M β , and the other end of the fourth inductor L β Is connected to the non-common terminal of the secondary side of the coupling transformer CT β .

[0043] In the described energy storage embedded railway power conditioner, the first switch S α1 , the second switch S α2 , the third switch S α3 , the fourth switch S α4 , the fifth switch S β1 , the sixth switch S β2 , the seventh switch S β3 , and the eighth switch S β4 A total of eight switches are each paralleled with a freewheeling diode.

[0044] Figure 2 This is a simplified circuit diagram of the present invention. For the convenience of explaining and interpreting the present invention, as Figure 2 shown, only the secondary side of the coupling transformer connected to the energy storage embedded railway power conditioner is given for the coupling transformer.

[0045] The working mode 1 of the described energy storage embedded railway power conditioner is as Figure 3 shown. At this time, there is no power interaction between the energy storage battery and the traction power supply system, and the power is transferred between the α and β phase traction feeders. Considering the symmetry of both sides of the half-bridge back-to-back structure α and β, only the implementation manner of the unilateral half-bridge converter module is described. For the convenience of explaining and interpreting the working principle of the unilateral half-bridge converter module, taking the output current i of the coupling transformer α flowing into the half-bridge converter module from point M α as positive, this is the power input mode of the half-bridge converter module at this time. When the output current i α is in the reverse direction, it is the power output mode, with the middle DC link point O as the potential reference point. The specific working process is as Figure 4 shown. When the third switch S α3 and the fourth switch S α4 remain off, the first switch S α1 and the second switch S α2 conduct simultaneously. Since the voltage drop across both ends of the first capacitor C u is greater than the voltage drop across the secondary side of the coupling transformer, the current i α gradually decreases and the energy is stored in the first capacitor C u , and the first capacitor C u is charged. When the first switch S α1 and the second switch S α2 remain off, the third switch S α3 and the fourth switch S α4 conduct simultaneously. As Figure 5 shown, since the voltage drop across both ends of the second capacitor C d is less than the voltage drop across the secondary side of the coupling transformer, the second capacitor C d discharges and the current i α gradually increases. During this process, the power is transmitted from the coupling transformer through the half-bridge converter module to the middle DC link. When the output current iα When it is negative, the half-bridge converter module is in the power output mode. When the third switch S α3 and the fourth switch S α4 remain off, the first switch S α1 and the second switch S α2 conduct simultaneously. As shown in Figure 6 , since the voltage drop across the first capacitor C u is less than the voltage drop across the secondary side of the coupling transformer, the first capacitor C u discharges, and the absolute value of the current |i α | gradually increases. When the first switch S α1 and the second switch S α2 remain off, the third switch S α3 and the fourth switch S α4 conduct simultaneously. As shown in Figure 7 , since the voltage drop across the second capacitor C d is greater than the voltage drop across the secondary side of the coupling transformer, the absolute value of the current |i α gradually decreases and the energy is stored in the second capacitor C d , and the second capacitor C d is charged. During this process, the power is transmitted from the intermediate DC link to the coupling transformer through the half-bridge converter module.

[0046] The working mode 2 of the energy storage embedded railway power regulator is shown in Figure 8 . Since the power conversion mode of the unilateral half-bridge converter module has been described in working mode 1, only the conversion mode of the unilateral DC / DC circuit is described in this working mode. In working mode 2, the first switch S α1 , the second switch S α2 , the third switch S α3 , and the fourth switch S α4 constitute a half-bridge converter circuit. The energy storage battery B β is connected to the fifth switch S β2 , the seventh switch S β3 , the fifth switch S β1 , and the eighth switch S β4 to form a bidirectional DC / DC circuit. When the fifth switch S β1 and the eighth switch S β4 remain off, and the sixth switch S β2 and the seventh switch S β3 alternately conduct and turn off simultaneously, the bidirectional DC / DC circuit is in the boost conversion mode. The specific working process is shown in Figure 9 . When the sixth switch S β2 and the seventh switch S β3 conduct, the energy storage battery B β passes through the sixth switch S β2 and the seventh switch Sβ3 A short - circuit loop is formed. At this time, the output current of the energy - storage battery gradually increases and the energy is stored in the second inductor L Bβ , and the energy is transferred from the energy - storage battery B β to the second inductor L Bβ . When the sixth switch S β2 and the seventh switch S β3 are turned off simultaneously, as shown in Figure 10 , the output current of the energy - storage battery B β flows through the fifth switch S β1 , the eighth switch S β4 and the free - wheeling diode in antiparallel. The energy is transferred from the energy - storage battery B β and the second inductor L Bβ to the intermediate DC - link. When the sixth switch S β2 and the seventh switch S β3 remain off, and the fifth switch S β1 and the eighth switch S β4 alternately conduct and turn off simultaneously, the bidirectional DC / DC circuit is in the buck - converter mode. The specific working process is as shown in Figure 11 . When the fifth switch S β1 and the eighth switch S β4 conduct, a short - circuit loop is formed between the intermediate DC - link and the energy - storage battery B β . Since the DC - bus voltage is greater than the voltage of the energy - storage battery B β , the output current of the half - bridge converter flows through the fifth switch S β1 to the energy - storage battery B β to charge it. At this time, the current gradually increases and the energy is transferred to the second inductor L Bβ and the energy - storage battery B β . When the fifth switch S β1 and the eighth switch are turned off, as shown in Figure 12 , the input current of the energy - storage battery B β flows through the sixth switch S β2 , the seventh switch S β3 and the free - wheeling diode in antiparallel, and the current will gradually decrease. The energy is transferred from the second inductor L Bβ to the energy - storage battery B β . When the DC / DC circuit is in the boost - converter mode, the half - bridge converter circuit is in the power - output mode as described in working mode 1. At this time, the energy is transferred from the energy - storage battery to the α - phase traction feeder. When the DC / DC circuit is in the buck - converter mode, the half - bridge converter circuit is in the power - input mode as described in working mode 1. At this time, the energy is transferred from the α - phase traction feeder to the energy - storage battery B β . This working mode realizes the bidirectional flow of energy between the energy - storage battery B β and the α - phase traction feeder.

[0047] The working mode 3 of the energy storage embedded railway power conditioner is as follows Figure 13 As shown, since the power conversion mode of the single-sided half-bridge converter module has been described in working mode 1, only the DC / DC circuit conversion mode is described in this working mode. The fifth switch S β1 , the sixth switch S β2 and the seventh switch S β3 , the eighth switch S β4 constitute a half-bridge converter circuit. The energy storage battery B α passes through the second switch S α2 , the third switch S α3 , and the first switch S α1 , the fourth switch S α4 constitute a bidirectional DC / DC circuit. When the first switch S α1 , the fourth switch S α4 remain off, and the second switch S α2 , the third switch S α3 are alternately turned on and off at the same time, the bidirectional DC / DC circuit is in the boost conversion mode. The specific working process is as follows Figure 14 As shown, when the second switch S α2 , the third switch S α3 are turned on, the energy storage battery B α forms a short-circuit loop through the second switch S α2 , the third switch S α3 . At this time, the output current of the energy storage battery gradually increases and the energy is stored in the first inductor L Bα , and the energy is transferred from the energy storage battery B α to the first inductor L Bα . When the second switch S α2 , the third switch S α3 are turned off, as shown in Figure 15 , the output current of the energy storage battery B α flows through the freewheeling diodes of the first switch S α1 , the fourth switch S α4 , and the energy is transferred from the energy storage battery B α and the first inductor L Bα to the intermediate DC link. When the second switch S α2 , the third switch S α3 remain off, and the first switch S α1 , the fourth switch S α4 are alternately turned on and off at the same time, the bidirectional DC / DC circuit is in the buck conversion mode. The specific working process is as follows Figure 16 As shown, when the first switch S α1 , the fourth switch S α4 are turned on, the intermediate DC link and the energy storage battery B αA short - circuit loop is formed. Since the DC bus voltage is greater than the voltage of the energy - storage battery B α the output current of the half - bridge converter flows through the first switch S α1 towards the energy - storage battery B α to charge it. At this time, the current gradually increases and the energy is transferred to the first inductor L Bα and the energy - storage battery B α When the first switch S α1 and the fourth switch S α4 are turned off, as shown in Figure 17 the input current of the energy - storage battery B α flows through the antiparallel diode of the second switch S α2 and the third switch S α3 for free - wheeling, and the current will gradually decrease. The energy is transferred from the first inductor L Bα to the energy - storage battery B α Since the half - bridge back - to - back converter structure is symmetric, the power interaction mode of working mode 3 is similar to that of working mode 2. This working mode realizes the bidirectional energy flow between the energy - storage battery B α and the β - phase traction feeder.

[0048] It should be understood that the above description is relatively detailed and should not be regarded as a limitation on the protection scope of the invention patent. For those skilled in the art of the present utility model, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit of the present utility model or exceeding the scope defined by the appended claims shall be included within the protection scope of the present utility model.

Claims

1. An energy storage embedded railway power conditioner, characterized in that: It includes an energy storage battery, a coupling transformer, and a half-bridge converter module; the half-bridge converter module includes a pair of four-switch bridge arms formed by four power electronic switches connected in series and an intermediate DC link formed by two capacitors connected in series, the two four-switch bridge arms are connected to the intermediate DC link to form a half-bridge back-to-back structure, and the coupling transformer CT α , CT β The primary side is connected to the α and β phase traction feeders respectively, the secondary side common end is connected to the middle point O of the intermediate DC link, and the secondary side non-common end is connected through the third inductor L α , the fourth inductor L β and the midpoint M of the four switch bridge arms on the α and β sides α 、M β connected.

2. The energy storage embedded railway power conditioner according to claim 1, characterized in that: The energy storage embedded railway power regulator includes a first switch S α1 , the second switch S α2 , the third switch S α3 , the fourth switch S α4 A four-switch bridge arm on the α side is connected in series, and the first switch S α1 The collector is connected to the intermediate DC link point P, and the first switch S α1 The emitter and the second switch S α2 The collector is connected, and the connection point is U α , the second switch S α2 The emitter and the third switch S α3 The collector is connected, and the connection point is M α , the third switch S α3 The emitter and the fourth switch S α4 The collector is connected, and the connection point is D α , the fourth switch S α4 The emitter is connected to point N in the intermediate DC link.

3. The energy storage embedded railway power conditioner according to claim 1, characterized in that: The energy storage embedded railway power regulator includes a fifth switch S β1 , the sixth switch S β2 , the seventh switch S β3 , the eighth switch S β4 A β-side four-switch bridge arm is formed in series, and the fifth switch S β1 The collector is connected to the intermediate DC link point P, and the fifth switch S β1 The emitter and the sixth switch S β2 The collector is connected, and the connection point is U β , the sixth switch S β2 The emitter and the seventh switch S β3 The collector is connected, and the connection point is M β , the seventh switch S β3 The emitter and the eighth switch S β4 The collector is connected, and the connection point is D β , the eighth switch S β4 The emitter is connected to point N in the intermediate DC link.

4. The energy storage embedded railway power conditioner according to claim 1, characterized in that: Energy storage battery B α The positive electrode and the first inductor L Bα One end is connected to the first inductor L Bα The other end is connected to the four-switch bridge arm U on the α side α The points are connected, energy storage battery B α Negative electrode and α side four switch bridge arm D α The points are connected, energy storage battery B β The positive electrode and the second inductor L Bβ One end is connected to the second inductor L Bβ The other end is connected to the β side four switch bridge arm U β The points are connected, energy storage battery B β Negative electrode and β side four switch bridge arm D β The dots are connected.

5. The energy storage embedded railway power conditioner according to claim 1 is characterized by: The first capacitor C u and the second capacitor C d The intermediate DC link is formed in series, and the connection point is point O, which is connected to the coupling transformer CT. α , CT β The secondary side common terminals are connected.

6. The energy storage embedded railway power conditioner according to claim 1, characterized in that: Energy storage embedded railway power regulator α side through M α Point and the third inductor L α One end is connected to the third inductor L α The other end is connected to the coupling transformer CT α The secondary side is connected to the non-common end, and the β side of the energy storage embedded railway power regulator is connected through M β Point and the fourth inductor L β One end is connected to the fourth inductor L β The other end is connected to the coupling transformer CT β The secondary side non-common terminals are connected.

7. The energy storage embedded railway power conditioner according to claim 1, characterized in that: In the two four-switch bridge arms, the first switch S α1 , the second switch S α2 , the third switch S α3 , the fourth switch S α4 , the fifth switch S β1 , the sixth switch S β2 , the seventh switch S β3 , the eighth switch S β4 A total of eight switches are connected in parallel with a reverse freewheeling diode.

8. The energy storage embedded railway power conditioner according to claim 1, characterized in that: The energy storage embedded railway power conditioner can be applied to a multiple structure through series and parallel connection to expand capacity.

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