Alternating current and direct current hybrid flexible power supply system for strait-crossing railway and control method

Abstract

The invention discloses an alternating current and direct current hybrid flexible power supply system for a strait-crossing railway and a control method. The system comprises a first three-phase power system, a first center station, a second three-phase power system, a second center station, an offshore wind power system and a strait-crossing railway tunnel power supply system. According to the invention, coordination control of load energy along a three-phase power grid, a center station, an offshore wind power system, an energy storage device, a train and a traction network can be realized, safe and stable power supply of a strait-crossing railway and loads along the line is ensured, and system energy is fully utilized.

Description

Technical Field

[0001] The present invention relates to the technical field of AC / DC hybrid flexible power supply, and in particular to an AC / DC hybrid flexible power supply system and a control method for a cross-strait railway. Background Art

[0002] In response to the needs of major cross-strait railway projects, my country's existing railway traction power supply system cannot guarantee stable and safe power supply for long-distance cross-sea tunnels, making it difficult to achieve full-length continuous operation of trains in the "land-strait-land" section, and it is very difficult to build a traction substation in the undersea tunnel that can access external power.

[0003] At present, the main method used in my country's railway tunnels is to set up relatively simple and small-footprint substations and auto-coupling substations inside the railway tunnels, and set up traction substations outside the tunnels, so as to realize long-distance tunnel power supply. However, it is difficult for the phase, amplitude and frequency between the two power supply arms output by the traction transformer after voltage reduction to be completely consistent, so it is necessary to carry out sub-division power supply. In addition, the traction load is a single-phase load, which will generate negative sequence current when reflected to the three-phase power grid, causing three-phase voltage imbalance, and there are also problems such as reactive power and harmonics. For long-distance cross-sea tunnels abroad, the Channel Tunnel between England and France adopts a 2×25kV power supply method. The substations at both ends of the UK and France provide 225kV and 25kV traction network power supply, and the autotransformer in the tunnel is used to reduce the voltage drop of the traction network. However, since the traction load is a single-phase load, there are also problems such as reactive power and negative sequence. Therefore, a large number of static VAR compensators (SVC) devices are installed along the line; the Øresund Tunnel in Denmark introduces power from the Danish and Swedish national power grids as power supply. Under normal circumstances, it is powered by the Danish power grid, and the Swedish power grid is used as a backup. If there is a problem on the Danish power grid side, it will switch to the Swedish power grid. This solution is suitable for situations where the power supply systems at both ends of the tunnel are different, but it is not suitable for power supply of long-distance channel tunnels.

[0004] For longer cross-strait railways, if the power supply systems on both sides of the strait are inconsistent, the required traction power supply system must not only ensure continuous power supply throughout the entire line and have good power quality, but also consider the compatibility of the power system. In addition, there are generally abundant wind power resources in the strait, and whether the offshore wind power resources can be fully utilized has also become a more important consideration. The existing traction power supply system cannot achieve through power supply due to the existence of electrical phase separation, and there are certain power quality problems in the system. At the same time, it is also incompatible with the power systems at both ends, and its structure determines that it is difficult to connect to new energy such as wind power. Therefore, it is urgent to design a power supply system for cross-strait railways and coordinate the control of system energy. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides an AC / DC hybrid flexible power supply system and control method for a cross-strait railway, so as to realize continuous power supply of trains in the "land-strait-land" section, ensure that the power quality of the cross-strait railway traction power supply system is good and compatible with different power systems; coordinate control of the cross-strait railway traction power supply system to realize full utilization of the strait offshore wind power and system energy.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention proposes an AC / DC hybrid flexible power supply system for a cross-strait railway, comprising:

[0008] A first three-phase power system is arranged on the land on one side of the strait and is used to provide electric energy to the first center connected thereto or receive electric energy returned by the first center connected thereto;

[0009] The first central station is arranged on the land on one side of the strait, and is used to collect electric energy from the first three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the first three-phase power system after adjusting the output voltage;

[0010] A second three-phase power system is provided on the land on the other side of the strait and is used to provide electric energy to a second center connected thereto or to receive electric energy returned thereto by a second center connected thereto;

[0011] The second center is located on the land on the other side of the strait, and is used to collect electric energy from the second three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the second three-phase power system after adjusting the output voltage;

[0012] An offshore wind power system, which is arranged on a strait and is used to generate electric energy, and output the generated electric energy to a DC bus connected thereto to provide electric energy to cross-strait railway power equipment and / or a cross-strait railway tunnel power supply system;

[0013] The cross-strait railway tunnel power supply system is set up on the strait and is used to receive the electric energy transmitted by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and store the received electric energy; or output the stored electric energy to the traction network and DC bus connected to it to provide electric energy to the cross-strait railway electrical equipment.

[0014] Furthermore, the cross-strait railway tunnel power supply system specifically includes:

[0015] At least one energy storage device, which is arranged in the cross-channel railway tunnel and is used to store the electric energy transmitted by the DC-DC converter connected thereto; or to transmit the stored electric energy through the DC-DC converter;

[0016] A DC-DC converter, which is arranged to correspond one-to-one with a storage device, is used to collect electric energy from a DC bus connected thereto, and transmit the collected electric energy to a corresponding energy storage device after performing electric energy conversion; or collect electric energy from a corresponding energy storage device, and transmit the collected electric energy to a DC bus after performing electric energy conversion;

[0017] At least one inverter station is arranged in the cross-strait railway tunnel, which is used to collect electric energy from the DC bus connected to it, and transmit the collected electric energy to the traction network connected to it after power conversion to provide electric energy to the cross-strait railway electrical equipment; or collect electric energy from the traction network, and transmit the collected electric energy to the DC bus after power conversion.

[0018] Furthermore, the offshore wind power system specifically includes:

[0019] at least one offshore wind turbine, which is disposed on the strait and is used to generate electric energy and transmit the generated electric energy to a step-up transformer connected thereto;

[0020] A step-up transformer, which is arranged to correspond to each offshore wind turbine one by one, and is used to step up and transform the electric energy transmitted by the corresponding offshore wind turbine and then transmit it to the busbar;

[0021] The offshore converter station is arranged on the strait, and is used to collect electric energy from the busbar, and then convert the collected electric energy into electric energy and output it to the first onshore converter station and the second onshore converter station through two submarine cables respectively;

[0022] The first onshore converter station is located on the land on one side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system;

[0023] The second onshore converter station is located on the other side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway electrical equipment and / or the cross-strait railway tunnel power supply system.

[0024] Furthermore, the cross-strait railway electrical equipment specifically includes:

[0025] Loads along the cross-channel railway operating trains and / or cross-channel railway tunnels.

[0026] In a second aspect, the present invention proposes a control method for the above-mentioned AC / DC hybrid flexible power supply system for cross-strait railways, comprising the following steps:

[0027] S1. Obtaining the operating conditions of trains running in a cross-strait railway tunnel;

[0028] S2, obtaining the charge state of the energy storage device in the cross-strait railway tunnel power supply system;

[0029] S3. Based on the acquired operating conditions of the running trains and the charge state of the energy storage device, the first center, the second center, the offshore wind power system and the cross-strait railway tunnel power supply system are used to coordinate power supply control and energy allocation for the cross-strait railway electrical equipment.

[0030] Furthermore, the operating conditions of the running train specifically include:

[0031] Traction and regenerative braking conditions.

[0032] Furthermore, the charge state of the energy storage device specifically includes:

[0033] Minimum state of charge, intermediate state of charge, and maximum state of charge.

[0034] Furthermore, step S3 specifically includes:

[0035] When the operating condition of the running train is the traction condition, it is determined whether the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway power equipment;

[0036] If the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0037] If the energy storage device is in a minimum charge state or an intermediate charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is stored in the energy storage device;

[0038] If the energy storage device is in the maximum charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center;

[0039] If the output energy of the offshore wind power system is less than the energy required by the cross-channel railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state;

[0040] If the energy storage device is in the minimum charge state, the output energy of the center and the offshore wind power system will be supplied to the cross-strait railway power equipment;

[0041] If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the energy storage device and the offshore wind power system is supplied to the cross-channel railway electrical equipment.

[0042] Furthermore, step S3 specifically includes:

[0043] When the operating condition of the running train is the regenerative braking condition, judging whether the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel;

[0044] If the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0045] If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system is supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are stored in the energy storage device;

[0046] If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system is supplied to the loads along the traction network, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are returned to the three-phase power system through the nearest center;

[0047] If the output energy of the train regenerative braking system is less than the energy required by the load along the cross-strait railway tunnel, then determine whether the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel;

[0048] If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0049] If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the offshore wind power system is stored in the energy storage device;

[0050] If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-strait railway tunnel, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center;

[0051] If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is less than the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in an intermediate state of charge or a maximum state of charge;

[0052] If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the energy storage device are supplied to the loads along the cross-strait railway tunnel;

[0053] If the energy storage device is in a minimum charge state, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the center will be supplied to the loads along the cross-strait railway tunnel.

[0054] The present invention has the following beneficial effects:

[0055] (1) The present invention can achieve coordinated control of the energy of three-phase power grids, central stations, offshore wind power systems, energy storage devices, trains, and loads along the traction network, ensuring safe and stable power supply to cross-strait railways and loads along the line, and making full use of system energy.

[0056] (2) The AC / DC hybrid flexible power supply system proposed in the present invention uses power electronic devices to make the output voltage controllable, which can realize traction power supply between different power systems and solve the incompatibility problem between different power systems.

[0057] (3) The AC / DC hybrid flexible power supply system proposed in the present invention uses power electronic devices at the center to achieve controllable output voltage, thereby eliminating electrical phase separation, realizing continuous power supply for trains in the "land-strait-land" section, and having good power quality; the inverter station in the tunnel can reduce the impact of voltage drop in the traction network and ensure that the traction network voltage is at a normal level.

[0058] (4) The AC / DC hybrid flexible power supply system proposed in the present invention can connect offshore wind power renewable energy and energy storage devices on the DC bus to fully utilize the abundant wind power resources in the strait. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a structural schematic diagram of an AC / DC hybrid flexible power supply system for a cross-strait railway in Example 1;

[0060] Figure 2 This is a schematic diagram of the structure of the cross-strait railway tunnel power supply system in Example 1;

[0061] Figure 3 The structural diagram of the offshore wind power system in Example 1 is

[0062] Figure 4 Schematic diagram of the control method in Example 2. DETAILED DESCRIPTION

[0063] 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.

[0064] Example 1

[0065] like Figure 1 As shown, an embodiment of the present invention provides an AC / DC hybrid flexible power supply system for a cross-strait railway, comprising:

[0066] A first three-phase power system is arranged on the land on one side of the strait and is used to provide electric energy to the first center connected thereto or receive electric energy returned by the first center connected thereto;

[0067] The first central station is arranged on the land on one side of the strait, and is used to collect electric energy from the first three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the first three-phase power system after adjusting the output voltage;

[0068] A second three-phase power system is provided on the land on the other side of the strait and is used to provide electric energy to a second center connected thereto or to receive electric energy returned thereto by a second center connected thereto;

[0069] The second center is located on the land on the other side of the strait, and is used to collect electric energy from the second three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the second three-phase power system after adjusting the output voltage;

[0070] An offshore wind power system, which is arranged on a strait and is used to generate electric energy, and output the generated electric energy to a DC bus connected thereto to provide electric energy to cross-strait railway power equipment and / or a cross-strait railway tunnel power supply system;

[0071] The cross-strait railway tunnel power supply system is set up on the strait and is used to receive the electric energy transmitted by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and store the received electric energy; or output the stored electric energy to the traction network and DC bus connected to it to provide electric energy to the cross-strait railway electrical equipment.

[0072] In this embodiment, after the first three-phase power system A is powered, it is connected to the first central station M, and the first central station M uses power electronic devices to achieve controllable output voltage. The AC output of the first central station M is connected to the traction network PA1, and the DC output of the first central station M is connected to the DC bus PD1; similarly, after the second three-phase power system B is powered, it is connected to the second central station T, and the AC output of the second central station T is connected to the traction network PA2, and the DC output of the second central station M is connected to the DC bus PD2; the traction network and the DC bus supply power to the cross-strait railway tunnel; the output of the offshore wind power system is connected to PW1 and PW2 on the DC bus respectively.

[0073] In an optional embodiment of the present invention, the cross-strait railway tunnel power supply system specifically includes:

[0074] At least one energy storage device, which is arranged in the cross-channel railway tunnel and is used to store the electric energy transmitted by the DC-DC converter connected thereto; or to transmit the stored electric energy through the DC-DC converter;

[0075] A DC-DC converter, which is arranged to correspond one-to-one with a storage device, is used to collect electric energy from a DC bus connected thereto, and transmit the collected electric energy to a corresponding energy storage device after performing electric energy conversion; or collect electric energy from a corresponding energy storage device, and transmit the collected electric energy to a DC bus after performing electric energy conversion;

[0076] At least one inverter station is arranged in the cross-strait railway tunnel, which is used to collect electric energy from the DC bus connected to it, and transmit the collected electric energy to the traction network connected to it after power conversion to provide electric energy to the cross-strait railway electrical equipment; or collect electric energy from the traction network, and transmit the collected electric energy to the DC bus after power conversion.

[0077] In this embodiment, if Figure 2 As shown, the first inverter station N1 in the cross-channel railway tunnel takes power from the DC bus PN1 and is connected to the traction network point Pn1. Similarly, the nth inverter station Nn in the cross-channel railway tunnel takes power from the DC bus PNn and is connected to the traction network point Pnn. The first energy storage device E1 in the cross-channel railway tunnel undergoes power conversion through the DC converter ZE1 and its output is connected to the DC bus PE1. Similarly, the mth energy storage device Em in the cross-channel railway tunnel undergoes power conversion through the DC converter ZEm and its output is connected to the DC bus PEm. The line load L1 in the tunnel is connected to the traction network PL1. Similarly, the line load Lp is connected to the traction network PLp. After the traction network takes power, it supplies power to the cross-channel railway electrical equipment, which includes the cross-channel railway running trains and / or the line loads of the cross-channel railway tunnel, so as to ensure the normal operation of the locomotives and the line loads.

[0078] In an optional embodiment of the present invention, the offshore wind power system specifically includes:

[0079] at least one offshore wind turbine, which is disposed on the strait and is used to generate electric energy and transmit the generated electric energy to a step-up transformer connected thereto;

[0080] A step-up transformer, which is arranged to correspond to each offshore wind turbine one by one, and is used to step up and transform the electric energy transmitted by the corresponding offshore wind turbine and then transmit it to the busbar;

[0081] The offshore converter station is arranged on the strait, and is used to collect electric energy from the busbar, and then convert the collected electric energy into electric energy and output it to the first onshore converter station and the second onshore converter station through two submarine cables respectively;

[0082] The first onshore converter station is located on the land on one side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system;

[0083] The second onshore converter station is located on the other side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway electrical equipment and / or the cross-strait railway tunnel power supply system.

[0084] In this embodiment, if Figure 3As shown, the output power of the offshore wind turbine W1 is connected to the busbar through the step-up transformer T1, and similarly, the output power of the offshore wind turbine Wo is connected to the busbar through the step-up transformer To; after taking power from the busbar, the offshore converter station CS converts the power and outputs it in two ways, one is transmitted to the first onshore converter station CM via the submarine cable LM, and the output of the first onshore converter station CM is connected to the DC bus point PW1, and the other is transmitted to the second onshore converter station CT via the submarine cable LT, and the output of the second onshore converter station CT is connected to the DC bus point PW2.

[0085] Example 2

[0086] like Figure 4 As shown, the embodiment of the present invention provides a control method applied to an AC / DC hybrid flexible power supply system for a cross-strait railway described in Example 1, comprising the following steps S1 to S3:

[0087] S1. Obtaining the operating conditions of trains running in a cross-strait railway tunnel;

[0088] S2, obtaining the charge state of the energy storage device in the cross-strait railway tunnel power supply system;

[0089] S3. Based on the acquired operating conditions of the running trains and the charge state of the energy storage device, the first center, the second center, the offshore wind power system and the cross-strait railway tunnel power supply system are used to coordinate power supply control and energy allocation for the cross-strait railway electrical equipment.

[0090] In an optional embodiment of the present invention, the operating condition of the running train specifically includes a traction condition and a regenerative braking condition.

[0091] Among them, if the locomotive is in traction condition, the central stations at both ends of the tunnel, the offshore wind power system and the energy storage device in the tunnel will coordinate power supply, and the electric locomotive and the loads along the traction network will draw power from the traction network.

[0092] If the locomotive is in regenerative braking condition, the power supply is coordinated by the central stations at both ends of the tunnel, the offshore wind power system, the energy storage device in the tunnel, and the regenerative braking energy of the train, and the loads along the traction network draw power from the traction network.

[0093] In an optional embodiment of the present invention, the charge state of the energy storage device specifically includes a minimum charge state, an intermediate charge state and a maximum charge state. This embodiment implements coordinated energy control based on the three charge states of the energy storage device.

[0094] In an optional embodiment of the present invention, step S3 specifically includes:

[0095] When the operating condition of the running train is the traction condition, it is determined whether the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway power equipment;

[0096] If the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0097] If the energy storage device is in a minimum charge state or an intermediate charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is stored in the energy storage device;

[0098] If the energy storage device is in the maximum charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center;

[0099] If the output energy of the offshore wind power system is less than the energy required by the cross-channel railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state;

[0100] If the energy storage device is in the minimum charge state, the output energy of the center and the offshore wind power system will be supplied to the cross-strait railway power equipment;

[0101] If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the energy storage device and the offshore wind power system is supplied to the cross-channel railway electrical equipment.

[0102] Specifically, when the locomotive is in traction condition, the load on the locomotive and along the traction network is the power load.

[0103] If the offshore wind power system output energy EW is greater than or equal to the energy ET and EL required by the locomotive and the loads along the traction network, that is, EW≥ET+EL is satisfied, and the energy storage device is in the minimum charge state SOCL or the intermediate charge state SOCM, then the AC / DC hybrid flexible power supply system is in the first working state, specifically: the offshore wind power system outputs energy to supply the locomotive and the loads along the traction network, and the excess energy is stored in the energy storage device; if the offshore wind power system outputs energy EW greater than or equal to the energy ET and EL required by the locomotive and the loads along the traction network, that is, EW≥ET+EL is satisfied, and the energy storage device is in the maximum charge state SOCH, then the AC / DC hybrid flexible power supply system is in the second working state, specifically: the offshore wind power system outputs energy to supply the locomotive and the loads along the traction network, and the remaining energy is returned to the three-phase power grid through the nearest center.

[0104] If the output energy EW of the offshore wind power system is less than the energy ET and EL required by the locomotive and the loads along the traction network, that is, EW<ET+EL and the energy storage device is in the minimum charge state SOCL, then the AC / DC hybrid flexible power supply system is in the third working state, specifically: the center and the offshore wind power system output energy to supply the locomotive and the loads along the traction network; if the output energy EW of the offshore wind power system is less than the energy ET and EL required by the locomotive and the loads along the traction network, that is, EW<ET+EL and the energy storage device is in the intermediate charge state SOCM or the maximum charge state SOCH, then the AC / DC hybrid flexible power supply system is in the fourth working state, specifically: the energy storage device in the tunnel and the offshore wind power system output energy to supply the locomotive and the loads along the traction network.

[0105] In an optional embodiment of the present invention, step S3 specifically includes:

[0106] When the operating condition of the running train is the regenerative braking condition, judging whether the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel;

[0107] If the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0108] If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system is supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are stored in the energy storage device;

[0109] If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system is supplied to the loads along the traction network, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are returned to the three-phase power system through the nearest center;

[0110] If the output energy of the train regenerative braking system is less than the energy required by the load along the cross-strait railway tunnel, then determine whether the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel;

[0111] If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state;

[0112] If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the offshore wind power system is stored in the energy storage device;

[0113] If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-strait railway tunnel, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center;

[0114] If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is less than the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in an intermediate state of charge or a maximum state of charge;

[0115] If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the energy storage device are supplied to the loads along the cross-strait railway tunnel;

[0116] If the energy storage device is in a minimum charge state, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the center will be supplied to the loads along the cross-strait railway tunnel.

[0117] Specifically, when the locomotive is in a regenerative braking condition, the load along the traction network is an electrical load.

[0118] If the regenerative braking energy ER of the train is greater than or equal to the energy EL required by the loads along the traction network, that is, ER≥EL is satisfied, and the energy storage device is in the minimum charge state SOCL or the intermediate charge state SOCM, then the AC / DC hybrid flexible power supply system is in the fifth working state, specifically: the regenerative braking train outputs energy to supply the loads along the traction network, and the remaining energy of regenerative braking and the energy of the offshore wind power system are stored in the energy storage device; if the regenerative braking energy ER of the train is greater than or equal to the energy EL required by the loads along the traction network, that is, ER≥EL is satisfied, and the energy storage device is in the maximum charge state SOCH, then the AC / DC hybrid flexible power supply system is in the sixth working state, specifically: the regenerative braking train outputs energy to supply the loads along the traction network, and the remaining energy of regenerative braking and the energy of the offshore wind power system are returned to the three-phase power grid through the nearest center.

[0119] If the regenerative braking energy ER of the train is less than the energy EL required by the loads along the traction network, and the sum of the regenerative braking energy ER of the train and the generated energy EW of the offshore wind power system is greater than or equal to the energy EL required by the loads along the traction network, that is, ER<EL&ER+EW≥EL is satisfied, and the energy storage device is in the minimum charge state SOCL or the intermediate charge state SOCM, then the AC / DC hybrid flexible power supply system is in the seventh working state, specifically: the regenerative braking train and the offshore wind power system output energy to supply the loads along the traction network, and the remaining energy is stored in the energy storage device; if the regenerative braking energy ER of the train is less than the energy EL required by the loads along the traction network, and the sum of the regenerative braking energy ER of the train and the generated energy EW of the offshore wind power system is greater than the energy EL required by the loads along the traction network, that is, ER<EL&ER+EW≥EL is satisfied, and the energy storage device is in the maximum charge state SOCH, then the AC / DC hybrid flexible power supply system is in the eighth working state, specifically: the regenerative braking train and the offshore wind power system output energy to supply the loads along the traction network, and the remaining energy is returned to the three-phase power grid through the nearest center.

[0120] If the regenerative braking energy ER of the train is less than the energy EL required by the loads along the traction network, and the sum of the regenerative braking energy ER of the train and the generated energy EW of the offshore wind power system is less than the energy EL required by the loads along the traction network, that is, ER<EL&ER+EW<EL is satisfied, and the energy storage device is in the intermediate charge state SOCM or the maximum charge state SOCH, then the AC / DC hybrid flexible power supply system is in the ninth working state, specifically: the regenerative braking train, the offshore wind power system and the energy storage device output energy to supply the loads along the traction network; if the regenerative braking energy ER of the train is less than the energy EL required by the loads along the traction network, and the sum of the regenerative braking energy ER of the train and the generated energy EW of the offshore wind power system is less than the energy EL required by the loads along the traction network, that is, ER<EL&ER+EW<EL is satisfied, and the energy storage device is in the minimum charge state SOCL, then the AC / DC hybrid flexible power supply system is in the tenth working state, specifically: the regenerative braking train, the offshore wind power system and the center output energy to supply the loads along the traction network.

[0121] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0122] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0124] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0125] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An AC / DC hybrid flexible power supply system for a cross-strait railway, characterized in that: include: A first three-phase power system is arranged on the land on one side of the strait and is used to provide electric energy to the first center connected thereto or receive electric energy returned by the first center connected thereto; The first central station is arranged on the land on one side of the strait, and is used to collect electric energy from the first three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the first three-phase power system after adjusting the output voltage; A second three-phase power system is provided on the land on the other side of the strait and is used to provide electric energy to a second center connected thereto or to receive electric energy returned thereto by a second center connected thereto; The second center is located on the land on the other side of the strait, and is used to collect electric energy from the second three-phase power system, and output the collected electric energy to the traction network and DC bus connected thereto after adjusting the output voltage, and provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; or receive the electric energy returned by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and return the received electric energy to the second three-phase power system after adjusting the output voltage; An offshore wind power system, which is arranged on a strait and is used to generate electric energy, and output the generated electric energy to a DC bus connected thereto to provide electric energy to cross-strait railway power equipment and / or a cross-strait railway tunnel power supply system; The cross-strait railway tunnel power supply system is set up on the strait and is used to receive the electric energy transmitted by the offshore wind power system through the DC bus, and / or receive the electric energy returned by the train regenerative braking system through the traction network, and store the received electric energy; or output the stored electric energy to the traction network and DC bus connected to it to provide electric energy to the cross-strait railway electrical equipment.

2. The AC / DC hybrid flexible power supply system for cross-strait railway according to claim 1, characterized in that: The cross-strait railway tunnel power supply system specifically includes: At least one energy storage device, which is arranged in the cross-channel railway tunnel and is used to store the electric energy transmitted by the DC-DC converter connected thereto; or to transmit the stored electric energy through the DC-DC converter; A DC-DC converter, which is arranged to correspond one-to-one with a storage device, is used to collect electric energy from a DC bus connected thereto, and transmit the collected electric energy to a corresponding energy storage device after performing electric energy conversion; or collect electric energy from a corresponding energy storage device, and transmit the collected electric energy to a DC bus after performing electric energy conversion; At least one inverter station is arranged in the cross-strait railway tunnel, which is used to collect electric energy from the DC bus connected to it, and transmit the collected electric energy to the traction network connected to it after power conversion to provide electric energy to the cross-strait railway electrical equipment; or collect electric energy from the traction network, and transmit the collected electric energy to the DC bus after power conversion.

3. The AC / DC hybrid flexible power supply system for cross-strait railway according to claim 1 is characterized in that: The offshore wind power system specifically includes: at least one offshore wind turbine, which is disposed on the strait and is used to generate electric energy and transmit the generated electric energy to a step-up transformer connected thereto; A step-up transformer, which is arranged to correspond to each offshore wind turbine one by one, and is used to step up and transform the electric energy transmitted by the corresponding offshore wind turbine and then transmit it to the busbar; The offshore converter station is arranged on the strait, and is used to collect electric energy from the busbar, and then convert the collected electric energy into electric energy and output it to the first onshore converter station and the second onshore converter station through two submarine cables respectively; The first onshore converter station is located on the land on one side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway power equipment and / or the cross-strait railway tunnel power supply system; The second onshore converter station is located on the other side of the strait and is used to convert the electric energy transmitted by the submarine cable and transmit it to the DC bus to provide electric energy to the cross-strait railway electrical equipment and / or the cross-strait railway tunnel power supply system.

4. The AC / DC hybrid flexible power supply system for cross-strait railway according to claim 1, characterized in that: The cross-strait railway electrical equipment specifically includes: Loads along the cross-channel railway operating trains and / or cross-channel railway tunnels.

5. A control method for an AC / DC hybrid flexible power supply system for a cross-strait railway as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Obtaining the operating conditions of trains running in a cross-strait railway tunnel; S2, obtaining the charge state of the energy storage device in the cross-strait railway tunnel power supply system; S3. Based on the acquired operating conditions of the running train and the charge state of the energy storage device, the first center, the second center, the offshore wind power system and the cross-strait railway tunnel power supply system are used to coordinate power supply control and energy allocation for the cross-strait railway electrical equipment.

6. The control method according to claim 5, characterized in that: The operating conditions of the running train specifically include: Traction and regenerative braking conditions.

7. The control method according to claim 6, characterized in that: The charge state of the energy storage device specifically includes: Minimum state of charge, intermediate state of charge, and maximum state of charge.

8. The control method according to claim 7, characterized in that: Step S3 specifically includes: When the operating condition of the running train is the traction condition, it is determined whether the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway power equipment; If the output energy of the offshore wind power system is greater than or equal to the energy required by the cross-strait railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state; If the energy storage device is in a minimum charge state or an intermediate charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is stored in the energy storage device; If the energy storage device is in the maximum charge state, the output energy of the offshore wind power system is supplied to the cross-channel railway power equipment, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center; If the output energy of the offshore wind power system is less than the energy required by the cross-channel railway electrical equipment, it is determined whether the energy storage device is in a minimum charge state; If the energy storage device is in the minimum charge state, the output energy of the center and the offshore wind power system will be supplied to the cross-strait railway power equipment; If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the energy storage device and the offshore wind power system is supplied to the cross-channel railway electrical equipment.

9. The control method according to claim 8, characterized in that: Step S3 specifically includes: When the operating condition of the running train is the regenerative braking condition, judging whether the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel; If the output energy of the train regenerative braking system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state; If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system is supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are stored in the energy storage device; If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system is supplied to the loads along the traction network, and the remaining energy of the train regenerative braking system and the output energy of the offshore wind power system are returned to the three-phase power system through the nearest center; If the output energy of the train regenerative braking system is less than the energy required by the load along the cross-strait railway tunnel, then determine whether the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel; If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is greater than or equal to the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in a minimum charge state or an intermediate charge state; If the energy storage device is in a minimum state of charge or an intermediate state of charge, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-channel railway tunnel, and the remaining energy of the offshore wind power system is stored in the energy storage device; If the energy storage device is in the maximum charge state, the output energy of the train regenerative braking system and the output energy of the offshore wind power system are supplied to the loads along the cross-strait railway tunnel, and the remaining energy of the offshore wind power system is returned to the three-phase power system through the nearest center; If the sum of the output energy of the train regenerative braking system and the output energy of the offshore wind power system is less than the energy required by the load along the cross-strait railway tunnel, it is determined whether the energy storage device is in an intermediate state of charge or a maximum state of charge; If the energy storage device is in an intermediate state of charge or a maximum state of charge, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the energy storage device are supplied to the loads along the cross-strait railway tunnel; If the energy storage device is in a minimum charge state, the output energy of the train regenerative braking system, the output energy of the offshore wind power system and the output energy of the center will be supplied to the loads along the cross-strait railway tunnel.

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