A multi-port energy routing system and energy management method thereof

Abstract

The present invention provides a multi-port energy routing system and an energy management method thereof, belonging to the technical field of urban rail transit power supply, comprising a 1.5kV DC bus, a bidirectional AC / DC port structure, a 380V AC port structure, a photovoltaic port structure and an energy storage port structure; the 1.5kV DC bus is respectively connected to the bidirectional AC / DC port structure, the 380V AC port structure, the photovoltaic port structure, the energy storage port structure and an external DC traction network, the bidirectional AC / DC port structure serves as a bidirectional AC / DC port of the multi-port energy routing system, the photovoltaic port structure serves as a photovoltaic port of the multi-port energy routing system, the energy storage port structure serves as an energy storage port of the multi-port energy routing system, and the 380V AC port structure serves as a 380V AC port of the multi-port energy routing system. The present invention solves the problems of the existing subway power supply system.

Description

Technical Field

[0001] The present invention belongs to the technical field of urban rail transit power supply, and in particular relates to a multi-port energy routing system and an energy management method thereof. Background Art

[0002] The traction power supply of the subway mainly adopts the 1500V DC power supply system, and the rectification method usually adopts two sets of diode uncontrolled rectifier units running in parallel. The diode uncontrolled rectifier unit provides the required electric energy for the operation of the subway train by taking power from the 10kV / 35kV AC medium voltage network. Due to the unidirectional conduction characteristics of the diode rectifier, the energy in the subway traction power supply system can only flow from the three-phase AC power grid to the DC traction network, and the energy can only flow in one direction. Therefore, when the train is in a regenerative braking condition and generates regenerative braking energy, the existing system structure cannot realize the utilization of the train's regenerative braking energy, causing the DC traction network voltage to rise and the train's regenerative braking energy to be wasted.

[0003] In addition, the existing subway system uses the power frequency transformer of the step-down substation to step down the 10kV / 35kV AC power to obtain 380V AC voltage, and supplies power to the subway power and lighting power supply system. Since the power frequency transformer is uncontrollable, the subway traction power supply and power and lighting power supply systems are independent of each other and the energy cannot be integrated and controlled. At the same time, the current structure of the existing traction power supply system determines that it is difficult to connect the system to new energy and energy storage systems.

[0004] In view of the problems existing in the existing subway system structure, a new power supply system is urgently needed to enable the subway system to effectively utilize regenerative braking energy, facilitate access to new energy and energy storage port structures, realize the energy interconnection between the subway traction power supply and the power lighting power supply system, improve the system's utilization of new energy and regenerative braking energy, and build a green and efficient subway traction power supply system. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a multi-port energy routing system and an energy management method thereof, which solve the problems of the existing subway power supply system.

[0006] In order to achieve the above objectives, the technical solution adopted by the present invention is: a multi-port energy routing system, including a 1.5kV DC bus, a bidirectional AC / DC port structure, a 380V AC port structure, a photovoltaic port structure and an energy storage port structure;

[0007] The 1.5kV DC bus is respectively connected to the bidirectional AC / DC port structure, the 380V AC port structure, the photovoltaic port structure, the energy storage port structure and the external DC traction network; the bidirectional AC / DC port structure serves as the bidirectional AC / DC port of the multi-port energy routing system; the photovoltaic port structure serves as the photovoltaic port of the multi-port energy routing system; the energy storage port structure serves as the energy storage port of the multi-port energy routing system; and the 380V AC port structure serves as the 380V AC port of the multi-port energy routing system.

[0008] Furthermore, the bidirectional AC / DC port structure includes a plurality of three-winding step-down transformers and a plurality of bidirectional converter modules; the primary side of each of the three-winding step-down transformers is a group of three-phase windings, and the secondary side is two groups of three-phase windings isolated from each other, and the primary winding is delta-connected, and the secondary winding is star-connected, and each of the bidirectional converter modules is a diode-clamped three-level structure;

[0009] The primary windings of the multiple three-winding step-down transformers serve together as the bidirectional AC / DC port of the multi-port energy routing system and are connected to the external 10kV / 35kV three-phase power grid; the two sets of secondary windings of each of the three-winding step-down transformers are respectively connected to the AC end of a bidirectional converter module, and the DC end of each of the bidirectional converter modules is connected to the 1.5kV DC bus.

[0010] Further, the 380V AC port structure includes a front-stage DC / DC converter, a rear-stage DC / AC three-phase inverter connected to the front-stage DC / DC converter, and a reserved intermediate DC port arranged between the front-stage DC / DC converter and the rear-stage DC / AC three-phase inverter, the structure of the front-stage DC / DC converter is a half-bridge diode clamped three-level dual active bridge structure, and the structure of the rear-stage DC / AC three-phase inverter is a diode clamped three-level structure;

[0011] The input side of the front-stage DC / DC converter is connected to the 1.5kV DC bus, the output side of the front-stage DC / DC converter is connected to the input side of the rear-stage DC / AC three-phase inverter, and the rear-stage DC / AC three-phase inverter outputs 380V AC power as the 380V AC port of the multi-port energy routing system.

[0012] Furthermore, the photovoltaic port structure is a Boost converter structure;

[0013] The input end of the Boost converter structure serves as a photovoltaic port of a multi-port energy routing system and is connected to an external photovoltaic device, and the output end of the Boost converter structure is connected to a 1.5 kV DC bus.

[0014] Furthermore, the energy storage port structure adopts a bidirectional DC / DC converter structure;

[0015] The low voltage side of the bidirectional DC / DC converter serves as the energy storage port of the multi-port energy routing system and is connected to an external energy storage device, and the high voltage side of the bidirectional DC / DC converter is connected to a 1.5 kV DC bus.

[0016] The beneficial effects of the present invention are:

[0017] The multi-port energy routing system proposed in the present invention can realize the functions of interconnection of multiple energy sources with electric energy as the core, AC / DC power conversion, bidirectional flow of energy, etc. It has universality and flexibility. It can not only realize the bidirectional flow of energy in the subway traction power supply system and the efficient and reasonable use of regenerative braking energy, but also enable the energy connection between the subway traction power supply and the power lighting system, reduce the DC bus voltage rise when the train is in regenerative braking conditions, and improve energy utilization. The multi-port energy routing system can be easily connected to photovoltaic new energy and energy storage devices through the DC bus, which can make full use of the photovoltaic new energy of the subway system, increase the input source of the subway power supply system, reduce the system's demand for external power grid energy, and make the multi-port energy routing system more green, energy-saving and economical, which is very consistent with the green and efficient development needs of the subway traction power supply system.

[0018] The present invention provides an energy management method for a multi-port energy routing system, comprising the following steps:

[0019] S1, determine whether the train consumes electric energy;

[0020] S2. According to the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, and according to the division results, the operation between the ports in the AC / DC port structure, the 380V AC port structure, the photovoltaic port structure and the energy storage port structure is managed to complete the energy management of the multi-port energy routing system.

[0021] The beneficial effects of the present invention are as follows: the energy management strategy proposed in the present invention and applicable to the multi-port energy routing system can realize the energy coordination of multi-channel energy and multi-standard electric energy between the multi-port energy routing system and the three-phase power grid, photovoltaic device, energy storage device, train traction load and subway power lighting load, ensure the coordinated and stable operation of each port of the multi-port energy routing system, realize the energy balance and optimization within the system, and ensure the safe and stable operation of the multi-port energy routing system.

[0022] Furthermore, in step S2, according to the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, which is specifically:

[0023] According to the train's power consumption and whether the photovoltaic device and energy storage device are working, the multi-port energy routing system is divided into 9 working conditions;

[0024] According to the regenerative braking energy returned by the train and whether the photovoltaic device and energy storage device are working, the multi-port energy routing system is divided into 12 working conditions;

[0025] According to the fact that there is no train running, when the power and lighting load of the multi-port energy routing system is operating normally, the multi-port energy routing system is divided into 9 operating conditions according to the power consumption of the train and whether the photovoltaic device and the energy storage device are working;

[0026] According to the situation that there is no train running, when the power lighting load power of the multi-port energy routing system is 0, the corresponding train stops running at night, the photovoltaic port is locked, and the energy storage device is charged by the three-phase power grid through the bidirectional AC / DC port structure and the energy storage port. When the energy storage capacity of the energy storage device is greater than or equal to 90% of its rated capacity, the energy storage port is locked.

[0027] The beneficial effects of the above further scheme are: based on the running status of the subway train, the working conditions of the system are divided in combination with the working conditions of the photovoltaic device and the energy storage device, which is convenient for setting the priority of power flow of each port of the system, giving priority to the normal operation of the subway train, and being able to reasonably allocate the energy of each port of the system. At the same time, the power grid electricity price is at a valley value at night, and the system charges the energy storage device from the three-phase grid in the night mode, which can realize peak power consumption, save electricity costs to a certain extent, and improve the economy of the system.

[0028] Furthermore, the 9 working conditions are:

[0029] The first working condition: the photovoltaic port and the energy storage port are locked, and neither the photovoltaic port nor the energy storage port participates in the energy regulation of the multi-port energy routing system. In this working condition, the bidirectional AC / DC port provides power to the train and power lighting loads.

[0030] The second working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy system, and the maximum discharge power of the energy storage device is greater than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage port provides power to the multi-port energy routing system, and the bidirectional AC / DC port is in standby state;

[0031] The third working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, and the maximum discharge power of the energy storage device is less than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the difference power of the multi-port energy routing system;

[0032] The fourth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. The photovoltaic port adopts maximum power tracking control. When the photovoltaic power is greater than the sum of the train running power and the power lighting load power, the photovoltaic energy is surplus. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system returns the surplus energy to the three-phase grid through the bidirectional AC / DC port.

[0033] The fifth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. When the photovoltaic power is less than the sum of the train running power and the power lighting load power, the difference power of the multi-port energy routing system is supplemented by the bidirectional AC / DC port. Under this working condition, the photovoltaic port and the bidirectional AC / DC port provide power to the multi-port energy routing system.

[0034] The sixth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the charging power of the energy storage device is greater than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system charges the energy storage device with the surplus power through the energy storage port. The bidirectional AC / DC port is in standby state.

[0035] The seventh working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the energy storage device charging power is less than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port. After the multi-port energy routing system charges the energy storage device through the energy storage port with the maximum charging power of the energy storage, the multi-port energy routing system returns the remaining power to the three-phase power grid through the bidirectional AC / DC port.

[0036] The eighth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is greater than the difference power required by the multi-port energy routing system. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the energy storage port operates at the difference power required by the multi-port energy routing system to provide power to the system. The bidirectional AC / DC port is in standby mode.

[0037] Ninth operating condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is less than the difference power required by the system. Under this operating condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power. The bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0038] The beneficial effect of the above further solution is: it is convenient for the system to maximize the use of photovoltaic energy and reduce the energy demand for the external three-phase power grid. The energy storage device regulates the energy flow within the system, reduces the energy returned to the three-phase power grid, improves the utilization rate of photovoltaic energy in the system, and makes the system greener and more economical.

[0039] Furthermore, the 12 working conditions are specifically as follows:

[0040] The tenth working condition: the photovoltaic port and the energy storage port are locked, and the train regenerative braking power is greater than the power lighting load power. Under this working condition, the multi-port energy routing system operates with surplus power through the bidirectional AC / DC port and returns the electric energy to the three-phase grid;

[0041] The eleventh working condition: the photovoltaic port and the energy storage port are locked, and the train regenerative braking power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port provides the difference power required by the multi-port energy routing system;

[0042] The twelfth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the surplus regenerative braking energy is absorbed by the energy storage port structure, and the bidirectional AC / DC port is on standby;

[0043] Thirteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port;

[0044] The fourteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port with the difference power required by the multi-port energy routing system, and the bidirectional AC / DC port is in standby operation;

[0045] Fifteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0046] The sixteenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the surplus power of the multi-port energy routing system to return energy to the three-phase grid;

[0047] The seventeenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the difference power required by the multi-port energy routing system to supply energy to the multi-port energy routing system;

[0048] Working condition 18: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the surplus power, and the bidirectional AC / DC port is in standby state.

[0049] Nineteenth working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port.

[0050] The 20th working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port operates with the difference power required by the multi-port energy routing system and provides power to the multi-port energy routing system. The bidirectional AC / DC port is in standby mode.

[0051] Working condition 21: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port structure provides electrical energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0052] The beneficial effects of the above further scheme are: it can realize the full utilization of regenerative braking energy and photovoltaic energy, improve energy utilization rate, reduce the fluctuation of DC bus voltage when the train runs in regenerative braking conditions, and ensure stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the structure of the multi-port energy routing system in the present invention.

[0054] Figure 2 It is a schematic diagram of the structure of the bidirectional AC / DC port in the present invention.

[0055] Figure 3 It is a structural schematic diagram of the 380V AC port in the present invention.

[0056] Figure 4 It is a schematic diagram of the structure of the photovoltaic port in the present invention.

[0057] Figure 5 It is a structural schematic diagram of the energy storage port in the present invention.

[0058] Figure 6 It is a flow chart of the method in the present invention. DETAILED DESCRIPTION

[0059] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0060] Example 1

[0061] like Figure 1-Figure 5 As shown, the present invention provides a multi-port energy routing system, including a 1.5kV DC bus, a bidirectional AC / DC port structure, a 380V AC port structure, a photovoltaic port structure and an energy storage port structure;

[0062] The 1.5kV DC bus is respectively connected to the bidirectional AC / DC port structure, the 380V AC port structure, the photovoltaic port structure, the energy storage port structure and the external DC traction network; the bidirectional AC / DC port structure serves as the bidirectional AC / DC port of the multi-port energy routing system; the photovoltaic port structure serves as the photovoltaic port of the multi-port energy routing system; the energy storage port structure serves as the energy storage port of the multi-port energy routing system; and the 380V AC port structure serves as the 380V AC port of the multi-port energy routing system.

[0063] The bidirectional AC / DC port structure includes multiple three-winding step-down transformers and multiple bidirectional converter modules; the primary side of each three-winding step-down transformer is a group of three-phase windings, and the secondary side is two groups of three-phase windings isolated from each other, and the primary winding is delta-connected, and the secondary winding is star-connected, and each of the bidirectional converter modules is a diode-clamped three-level structure; the primary windings of the multiple three-winding step-down transformers serve together as the bidirectional AC / DC port of the multi-port energy routing system, and are connected to the external 10kV / 35kV three-phase power grid; the two groups of secondary windings of each three-winding step-down transformer are respectively connected to the AC end of a bidirectional converter module, and the DC end of each bidirectional converter module is connected to the 1.5kV DC bus.

[0064] The 380V AC port structure includes a front-stage DC / DC converter, a rear-stage DC / AC three-phase inverter connected to the front-stage DC / DC converter, and a reserved intermediate DC port arranged between the front-stage DC / DC converter and the rear-stage DC / AC three-phase inverter. The structure of the front-stage DC / DC converter is a half-bridge diode clamped three-level dual active bridge structure, and the structure of the rear-stage DC / AC three-phase inverter is a diode clamped three-level structure; the input side of the front-stage DC / DC converter is connected to a 1.5kV DC bus, the output side of the front-stage DC / DC converter is connected to the input side of the rear-stage DC / AC three-phase inverter, and the rear-stage DC / AC three-phase inverter outputs 380V AC power as a 380V AC port of the multi-port energy routing system.

[0065] The photovoltaic port structure is a Boost converter structure; the input end of the Boost converter structure serves as a photovoltaic port of a multi-port energy routing system and is connected to an external photovoltaic device, and the output end of the Boost converter structure is connected to a 1.5kV DC bus.

[0066] The energy storage port structure adopts a bidirectional DC / DC converter structure; the low-voltage side of the bidirectional DC / DC converter serves as the energy storage port of the multi-port energy routing system and is connected to an external energy storage device, and the high-voltage side of the bidirectional DC / DC converter is connected to a 1.5kV DC bus.

[0067] In this embodiment, Figure 1 As shown, the 1.5kV DC bus of the multi-port energy routing system is connected to the DC traction network. When the train consumes electric energy, the multi-port energy routing system provides electric energy to the train connected to the DC traction network through the 1.5kV DC bus. When the train brakes to generate regenerative braking energy, the train returns the regenerative braking energy to the multi-port energy routing system through the DC traction network and the 1.5kV DC bus.

[0068] In this embodiment, Figure 2 As shown, the structure of the bidirectional AC / DC port includes two three-winding step-down transformers and four bidirectional converter modules. Each three-winding step-down transformer is a D / y / y structure (the primary side of each three-winding step-down transformer is a group of three-phase windings, and its secondary side is two groups of three-phase windings isolated from each other, and the primary winding is a delta connection, the secondary winding is a star connection, and each bidirectional converter module is a diode clamped three-level structure), and each bidirectional converter module is a diode clamped three-level structure. The primary windings of the two three-winding step-down transformers are used together as the interface for the bidirectional AC / DC port of the multi-port energy routing system to be connected to the external connection, connecting the 10kV / 35kV three-phase power grid. The two secondary windings of each three-winding step-down transformer are respectively connected to the AC end of a bidirectional converter module. The DC end of each bidirectional converter module is connected to the 1.5kV DC bus. By controlling the bidirectional converter module, such as adopting double closed-loop control based on dq decoupling, bidirectional energy flow between the 10kV / 35kV three-phase power grid and the 1.5kV DC bus can be achieved.

[0069] In this embodiment, Figure 3As shown, the 380V AC port structure includes a front-stage DC / DC converter and a rear-stage DC / AC three-phase inverter, as well as a reserved DC port in the middle. The structure of the front-stage DC / DC converter is a half-bridge diode clamped three-level dual active bridge structure, and the structure of the rear-stage DC / AC three-phase inverter is a diode clamped three-level structure. The input side of the front-stage DC / DC converter is connected to the 1.5kV DC bus, and the output side is connected to the input side of the rear-stage DC / AC three-phase inverter. The rear-stage DC / AC three-phase inverter outputs 380V AC power as the 380V AC port of the multi-port energy routing system to supply power to the subway power lighting load. An intermediate DC port is reserved at the connection between the front-stage DC / DC converter and the rear-stage DC / AC converter. In the future, with the development of new energy or changes in subway load characteristics, other conversion devices can be connected through the intermediate DC port.

[0070] In this embodiment, the 380V AC port is facing the power and lighting load of the subway, and can replace the industrial frequency transformer in the subway step-down substation. The purpose is to be able to feed back the train's regenerative braking energy to the power and lighting load, and to further reduce the DC bus voltage rise when the train is in a regenerative braking condition.

[0071] In this embodiment, the control systems of the front-stage DC / DC converter and the rear-stage DC / AC converter are designed independently, and the front-stage DC / DC converter controls the intermediate DC voltage to be 750V. The transformer ratio of the front-stage DC / DC converter is designed to be 1, and a single voltage closed-loop control and a single phase-shift modulation strategy are adopted to achieve a stable output of 750V DC voltage. The rear-stage DC / AC inverter provides a three-phase power supply with a stable voltage to the three-phase load, and adopts a voltage closed-loop control to achieve stable output voltage amplitude and frequency.

[0072] In this embodiment, Figure 4 As shown, the photovoltaic port structure adopts a Boost converter structure. The input end of the Boost converter is used as the photovoltaic port of the multi-port energy routing system and is connected to an external photovoltaic device. The output end of the Boost converter is connected to a 1.5kV DC bus.

[0073] In this embodiment, the photovoltaic port is the port for the multi-port energy routing system to access the photovoltaic energy. The photovoltaic device converts light energy into electrical energy, and is composed of a plurality of photovoltaic cells. The operation of the photovoltaic cell is affected by external factors such as light intensity and operating temperature. In order to enable the photovoltaic device to work in the best state and maximize the output power of the photovoltaic cell, a variable step size perturbation algorithm is used to realize the Boost converter to track the maximum power point of the photovoltaic cell.

[0074] In this embodiment, Figure 5As shown, the energy storage port structure adopts a bidirectional DC / DC converter structure. The low-voltage side of the bidirectional DC / DC converter serves as the energy storage port of the multi-port energy routing system, connected to an external energy storage device, and the high-voltage side of the bidirectional DC / DC converter is connected to a 1.5kV DC bus.

[0075] In this embodiment, the energy storage port structure realizes charging and discharging through a bidirectional DC / DC converter, and can realize bidirectional energy flow between the multi-port energy routing system. The energy storage port structure can select energy storage methods such as flywheel energy storage, supercapacitor energy storage and battery energy storage according to needs. The bidirectional DC / DC converter uses a bidirectional Buck-Boost converter topology circuit and adopts a current control strategy to control the charging and discharging of the energy storage port structure.

[0076] In this embodiment, the present invention can realize the functions of interconnection of multiple energy sources with electric energy as the core, AC / DC power conversion, bidirectional flow of energy, etc. through the above design, and has universality and flexibility. It can not only realize the bidirectional flow of energy in the subway traction power supply system and the efficient and reasonable use of regenerative braking energy, but also enable the energy connection between the subway traction power supply and the power lighting system, reduce the DC bus voltage rise when the train is in regenerative braking conditions, and improve energy utilization. The multi-port energy routing system can be easily connected to the photovoltaic new energy and energy storage port structure through the DC bus, which can make full use of the photovoltaic new energy of the subway system, increase the input source of the subway power supply system, reduce the system's demand for external power grid energy, and make the multi-port energy routing system more green, energy-saving and economical, which is very consistent with the green and efficient development needs of the subway traction power supply system.

[0077] Example 2

[0078] like Figure 6 As shown, the present invention provides an energy management method for a multi-port energy routing system, and its implementation method is as follows:

[0079] S1, determine whether the train consumes electric energy;

[0080] S2. Based on the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, and based on the division results, the operation between the ports in the AC / DC port structure, the 380V AC port structure, the photovoltaic device and the energy storage port structure is managed to complete the energy management of the multi-port energy routing system.

[0081] In step S2, according to the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, which is specifically:

[0082] According to the train's power consumption and whether the photovoltaic device and energy storage port structure are working, the multi-port energy routing system is divided into 9 working conditions;

[0083] According to the regenerative braking energy returned by the train and whether the photovoltaic device and energy storage device are working, the multi-port energy routing system is divided into 12 working conditions;

[0084] According to the situation that there is no train running, when the power and lighting load of the multi-port energy routing system is operating normally, the energy management strategy of the multi-port energy routing system is consistent with the situation according to the train consuming electric energy;

[0085] According to the situation that there is no train running, when the power lighting load power of the multi-port energy routing system is 0, the corresponding train stops running at night, the photovoltaic port is locked, and the energy storage device is charged by the three-phase power grid through the bidirectional AC / DC port structure and the energy storage port. When the energy storage capacity of the energy storage device is greater than or equal to 90% of its rated capacity, the energy storage port is locked.

[0086] In this embodiment, the photovoltaic port is a unidirectional input power source port. The output power of the photovoltaic array, that is, the input power of the photovoltaic port, is only affected by the external light intensity and temperature changes. After adopting the above control strategy, the photovoltaic array always operates in the maximum power output state according to different light intensities when working. At this time, the photovoltaic port is regarded as a port with stable energy input. The 380V AC port is a unidirectional output port that supplies power to the subway power lighting load. Combined with the actual situation, the power of the subway power lighting load is usually within a stable range, so it can be regarded as a constant power output port in energy analysis.

[0087] In this embodiment, in step S2, the train consumes electric energy, that is, P T >0(P T is the total power of the train load). According to whether the photovoltaic device and the energy storage port structure are working, and the maximum charge and discharge power of the energy storage port structure, the multi-port routing system can be divided into 9 working conditions:

[0088] The first working condition: the photovoltaic port and the energy storage port are locked, and neither the photovoltaic port nor the energy storage port participates in the energy regulation of the multi-port energy routing system. In this working condition, the bidirectional AC / DC port provides power to the train and power lighting loads.

[0089] The second working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy system, and the maximum discharge power of the energy storage device is greater than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage port provides power to the multi-port energy routing system, and the bidirectional AC / DC port is in standby state;

[0090] The third working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, and the maximum discharge power of the energy storage device is less than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the difference power of the multi-port energy routing system;

[0091] The fourth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. The photovoltaic port adopts maximum power tracking control. When the photovoltaic power is greater than the sum of the train running power and the power lighting load power, the photovoltaic energy is surplus. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system returns the surplus energy to the three-phase grid through the bidirectional AC / DC port.

[0092] The fifth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. When the photovoltaic power is less than the sum of the train running power and the power lighting load power, the difference power of the multi-port energy routing system is supplemented by the bidirectional AC / DC port. Under this working condition, the photovoltaic port and the bidirectional AC / DC port provide power to the multi-port energy routing system.

[0093] The sixth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the charging power of the energy storage device is greater than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system charges the energy storage device with the surplus power through the energy storage port. The bidirectional AC / DC port is in standby state.

[0094] The seventh working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the energy storage device charging power is less than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port. After the multi-port energy routing system charges the energy storage device through the energy storage port with the maximum charging power of the energy storage, the multi-port energy routing system returns the remaining power to the three-phase power grid through the bidirectional AC / DC port.

[0095] The eighth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is greater than the difference power required by the multi-port energy routing system. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the energy storage port operates at the difference power required by the multi-port energy routing system to provide power to the system. The bidirectional AC / DC port is in standby mode.

[0096] Ninth operating condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is less than the difference power required by the system. Under this operating condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power. The bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0097] In this embodiment, in step S2, the train returns regenerative braking energy, that is, P T <0(P T is the total power of the train load). According to whether the photovoltaic device and the energy storage port structure are working, the multi-port energy routing system can be divided into 12 working conditions, which are:

[0098] The eleventh working condition: the photovoltaic port and the energy storage port are locked, and the train regenerative braking power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port provides the difference power required by the multi-port energy routing system;

[0099] The twelfth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the surplus regenerative braking energy is absorbed by the energy storage port structure, and the bidirectional AC / DC port is on standby;

[0100] Thirteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port;

[0101] The fourteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port with the difference power required by the multi-port energy routing system, and the bidirectional AC / DC port is in standby operation;

[0102] Fifteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0103] The sixteenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the surplus power of the multi-port energy routing system to return energy to the three-phase grid;

[0104] The seventeenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the difference power required by the multi-port energy routing system to supply energy to the multi-port energy routing system;

[0105] Working condition 18: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the surplus power, and the bidirectional AC / DC port is in standby state.

[0106] Nineteenth working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port.

[0107] The 20th working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port operates with the difference power required by the multi-port energy routing system and provides power to the multi-port energy routing system. The bidirectional AC / DC port is in standby mode.

[0108] Working condition 21: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port structure provides electrical energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

[0109] In this embodiment, in step S2, there is no train running in the multi-port energy routing system, and the power of the train is 0, that is, P T =0(P T is the total power of the train load). When the power and lighting load of the multi-port energy routing system operates normally, the operating state of the multi-port energy routing system is the same as P T >0. When the power of the multi-port energy routing system power lighting load is 0, it corresponds to the subway stopping operation at night. At this time, the multi-port routing system has the 22nd working condition:

[0110] Working condition 22: At this time, the photovoltaic port is locked, and the multi-port energy routing system charges the energy storage port structure from the three-phase grid through the bidirectional AC / DC port and the energy storage port. When the energy storage capacity of the energy storage port structure is greater than or equal to 90% of its rated capacity, the energy storage port is locked.

[0111] The present invention can realize the coordinated energy management between multi-channel energy sources and multi-standard electric energy in the system, and determine the working state of the system by judging whether the train consumes electric energy and combining whether the photovoltaic device and the energy storage port structure are working; according to the working state of the system, coordinate and manage the energy between the multi-port energy routing system and the three-phase power grid, photovoltaic device, energy storage port structure, train traction load and subway power lighting load.

Claims

1. A multi-port energy routing system, characterized in that: It includes 1.5kV DC bus, bidirectional AC / DC port structure, 380V AC port structure, photovoltaic port structure and energy storage port structure; The 1.5kV DC bus is respectively connected to the bidirectional AC / DC port structure, the 380V AC port structure, the photovoltaic port structure, the energy storage port structure and the external DC traction network; the bidirectional AC / DC port structure serves as the bidirectional AC / DC port of the multi-port energy routing system; the photovoltaic port structure serves as the photovoltaic port of the multi-port energy routing system; the energy storage port structure serves as the energy storage port of the multi-port energy routing system; and the 380V AC port structure serves as the 380V AC port of the multi-port energy routing system; The 380V AC port structure includes a front-stage DC / DC converter, a rear-stage DC / AC three-phase inverter connected to the front-stage DC / DC converter, and a reserved intermediate DC port arranged between the front-stage DC / DC converter and the rear-stage DC / AC three-phase inverter. The structure of the front-stage DC / DC converter is a half-bridge diode-clamped three-level dual active bridge structure, and the structure of the rear-stage DC / AC three-phase inverter is a diode-clamped three-level structure. The input side of the front-stage DC / DC converter is connected to the 1.5kV DC bus, the output side of the front-stage DC / DC converter is connected to the input side of the rear-stage DC / AC three-phase inverter, and the rear-stage DC / AC three-phase inverter outputs 380V AC power as the 380V AC port of the multi-port energy routing system.

2. The multi-port energy routing system according to claim 1, characterized in that: The bidirectional AC / DC port structure includes a plurality of three-winding step-down transformers and a plurality of bidirectional converter modules; the primary side of each of the three-winding step-down transformers is a group of three-phase windings, and the secondary side is two groups of three-phase windings isolated from each other, and the primary winding is delta-connected and the secondary winding is star-connected, and each of the bidirectional converter modules is a diode-clamped three-level structure; The primary windings of the multiple three-winding step-down transformers serve together as the bidirectional AC / DC port of the multi-port energy routing system and are connected to the external 10kV / 35kV three-phase power grid; the two sets of secondary windings of each of the three-winding step-down transformers are respectively connected to the AC end of a bidirectional converter module, and the DC end of each of the bidirectional converter modules is connected to the 1.5kV DC bus.

3. The multi-port energy routing system according to claim 1, characterized in that: The photovoltaic port structure is a Boost converter structure; The input end of the Boost converter structure serves as a photovoltaic port of a multi-port energy routing system and is connected to an external photovoltaic device, and the output end of the Boost converter structure is connected to a 1.5 kV DC bus.

4. The multi-port energy routing system according to claim 1, characterized in that: The energy storage port structure adopts a bidirectional DC / DC converter structure; The low voltage side of the bidirectional DC / DC converter serves as the energy storage port of the multi-port energy routing system and is connected to an external energy storage device, and the high voltage side of the bidirectional DC / DC converter is connected to a 1.5 kV DC bus.

5. An energy management method for a multi-port energy routing system, characterized in that: The following steps are involved: S1, determine whether the train consumes electric energy; S2. According to the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, and according to the division result, the operation between the ports in the AC / DC port structure, the 380V AC port structure, the photovoltaic port structure and the energy storage port structure is managed to complete the energy management of the multi-port energy routing system; In step S2, according to the result determined in step S1, the working conditions of the multi-port energy routing system are divided according to whether the photovoltaic device and the energy storage device are working, which is specifically: According to the train's power consumption and whether the photovoltaic device and energy storage device are working, the multi-port energy routing system is divided into 9 working conditions; According to the regenerative braking energy returned by the train and whether the photovoltaic device and energy storage device are working, the multi-port energy routing system is divided into 12 working conditions; According to the fact that there is no train running, when the power and lighting load of the multi-port energy routing system is operating normally, the multi-port energy routing system is divided into 9 operating conditions according to the power consumption of the train and whether the photovoltaic device and the energy storage device are working; According to the situation that there is no train running, when the power of the power lighting load of the multi-port energy routing system is 0, the corresponding train stops running at night, the photovoltaic port is locked, and the energy storage device is charged from the three-phase grid through the bidirectional AC / DC port structure and the energy storage port. When the energy storage capacity of the energy storage device is greater than or equal to 90% of its rated capacity, the energy storage port is locked; The 9 working conditions are: The first working condition: the photovoltaic port and the energy storage port are locked, and neither the photovoltaic port nor the energy storage port participates in the energy regulation of the multi-port energy routing system. In this working condition, the bidirectional AC / DC port provides power to the train and power lighting loads. The second working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy system, and the maximum discharge power of the energy storage device is greater than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage port provides power to the multi-port energy routing system, and the bidirectional AC / DC port is in standby state; The third working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, and the maximum discharge power of the energy storage device is less than the sum of the train running power and the power lighting load power. Under this working condition, the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the difference power of the multi-port energy routing system; The fourth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. The photovoltaic port adopts maximum power tracking control. When the photovoltaic power is greater than the sum of the train running power and the power lighting load power, the photovoltaic energy is surplus. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system returns the surplus energy to the three-phase grid through the bidirectional AC / DC port. The fifth working condition: the energy storage port is locked, and the photovoltaic port participates in the energy regulation of the multi-port energy routing system. When the photovoltaic power is less than the sum of the train running power and the power lighting load power, the difference power of the multi-port energy routing system is supplemented by the bidirectional AC / DC port. Under this working condition, the photovoltaic port and the bidirectional AC / DC port provide power to the multi-port energy routing system. The sixth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the charging power of the energy storage device is greater than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the multi-port energy routing system charges the energy storage device with the surplus power through the energy storage port. The bidirectional AC / DC port is in standby state. The seventh working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is greater than the sum of the train running power and the power lighting load power. The photovoltaic energy is surplus, and the energy storage device charging power is less than the surplus power of the photovoltaic port. Under this working condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port. After the multi-port energy routing system charges the energy storage device through the energy storage port with the maximum charging power of the energy storage, the multi-port energy routing system returns the remaining power to the three-phase power grid through the bidirectional AC / DC port. The eighth working condition: the photovoltaic port and the energy storage port both participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is greater than the difference power required by the multi-port energy routing system. Under this working condition, the photovoltaic device provides power to the multi-port energy routing system through the photovoltaic port, and the energy storage port operates at the difference power required by the multi-port energy routing system to provide power to the system. The bidirectional AC / DC port is in standby mode. Ninth operating condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The photovoltaic port power is less than the sum of the train running power and the power lighting load power. The photovoltaic port power is insufficient, and the energy storage device discharge power is less than the difference power required by the system. Under this operating condition, the photovoltaic device provides electric energy to the multi-port energy routing system through the photovoltaic port, and the energy storage device provides electric energy to the multi-port energy routing system through the energy storage port at the maximum discharge power. The bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

6. The energy management method of the multi-port energy routing system according to claim 5, characterized in that: The 12 working conditions are specifically: The tenth working condition: the photovoltaic port and the energy storage port are locked, and the train regenerative braking power is greater than the power lighting load power. Under this working condition, the multi-port energy routing system operates with surplus power through the bidirectional AC / DC port and returns the electric energy to the three-phase grid; The eleventh working condition: the photovoltaic port and the energy storage port are locked, and the train regenerative braking power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port provides the difference power required by the multi-port energy routing system; The twelfth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the surplus regenerative braking energy is absorbed by the energy storage port structure, and the bidirectional AC / DC port is on standby; Thirteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port; The fourteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port with the difference power required by the multi-port energy routing system, and the bidirectional AC / DC port is in standby operation; Fifteenth working condition: the photovoltaic port is locked, the energy storage port participates in the energy regulation of the multi-port energy routing system, the train regenerative braking power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum operating power of the energy storage port structure. Under this working condition, the energy storage port structure provides power to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system. The sixteenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the surplus power of the multi-port energy routing system to return energy to the three-phase grid; The seventeenth working condition: the energy storage port is locked, the photovoltaic port participates in the energy regulation of the multi-port energy routing system, and the sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power. Under this working condition, the bidirectional AC / DC port operates with the difference power required by the multi-port energy routing system to supply energy to the multi-port energy routing system; Working condition 18: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the surplus power, and the bidirectional AC / DC port is in standby state. Nineteenth working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is greater than the power lighting load power, and the surplus power of the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the multi-port energy routing system charges the energy storage port structure through the energy storage port with the maximum charging power of the energy storage, and then the multi-port energy routing system returns the remaining power to the three-phase grid through the bidirectional AC / DC port. The 20th working condition: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is less than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port operates with the difference power required by the multi-port energy routing system and provides power to the multi-port energy routing system. The bidirectional AC / DC port is in standby mode. Working condition 21: Both the photovoltaic port and the energy storage port participate in the energy regulation of the multi-port energy routing system. The sum of the regenerative braking power and the photovoltaic port power is less than the power lighting load power, and the difference power required by the multi-port energy routing system is greater than the maximum charging power of the energy storage port structure. Under this working condition, the energy storage port structure provides electrical energy to the multi-port energy routing system through the energy storage port at the maximum discharge power, and the bidirectional AC / DC port supplements the remaining difference power required by the multi-port energy routing system.

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