Bilateral power supply ride-through power utilization system and control method for traction network

Abstract

The present invention provides a bilateral power supply ride-through power utilization system and control method for a traction network, which relates to the technical field of electric railway power supply. The system includes a power converter BCSa and a controller CCa installed in a substation TSa, and a power converter BCSb and a controller CCb installed in a substation TSb, the traction network OCS between the substation TSa and the substation TSb adopts bilateral power supply, the controller CCa is used to obtain the power information of the substation TSa in real time, the controller CCb is used to obtain the power information of the substation TSb in real time, the controller CCa and the controller CCb exchange information with the OFL through an optical fiber, the controller CCa controls the power converter BCSa to utilize the ride-through power according to the information exchange result, or the controller CCb controls the power converter BCSb to utilize the ride-through power according to the information exchange result, so that the ride-through power returning to the power grid meets a predetermined requirement.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of Chinese Patent Application No. 202210261871.3, filed on March 17, 2022, the contents of which are incorporated herein by reference.

[0002] The present invention relates to the technical field of AC electric railway traction power supply, and in particular to a bilateral power supply ride-through power utilization system and control method for traction networks. [Background technology]

[0003] Electrical phase splitting in electrified railways is a weak link in the entire traction power supply system, and the neutral section of the electrical phase split forms a dead section, causing power supply interruptions. While the dead section of the neutral section is typically only a few tens of meters, the power outage distance when controlling trains to automatically pass through a phase split can reach 500 meters or more, significantly restricting the smooth operation of trains and even causing trains to stop on slopes when going uphill. Bilateral power supply for electrified railways eliminates electrical phase splitting in certain sections, eliminating dead sections and ensuring continuous power supply to trains while also eliminating the risk of excessive phase splitting. Bilateral power supply has the advantages of high power supply reliability, good grid voltage level, high power supply capacity, and low power loss.

[0004] Typically, a bilateral power supply traction network forms a parallel structure with the power grid via traction substations on both sides. When the traction network is unloaded, power and current flow through it. This power is called ride-through power (the corresponding current is called balanced current). At this time, ride-through power flows in from one traction substation and out from the other. That is, when ride-through power flows from the power grid to the traction substation of the traction network, it is in a load (power consumption) state. When ride-through power flows from the traction network to the traction substation of the power grid, it is in a power generation state. Because bilateral power supply changes the structure of the power grid, two important technical problems must be solved to implement bilateral power supply.

[0005] The first issue concerns the issue of relay protection for the power grid and traction network. Relay protection must have a wider protection scope and be able to trip the traction network in conjunction with the power grid to cut off the power flow when a fault occurs. This can be perfectly resolved by arranging transmission line protection for the power grid and arranging tiered protection for the traction network.

[0006] The second issue concerns the impact of ride-through power on the power grid and its metering. When ride-through power is returned to the power grid, it is equivalent to power generation by the traction substation. If the backfeed power is metered backward, i.e., treated as power generation and offset against the power consumption of another traction substation, users will not incur any economic loss. However, if the backfeed power is not metered or is metered forward when it is returned to the power grid, users will incur economic losses. In such cases, research is needed into how bilateral power supply can reduce ride-through power or how to utilize ride-through power to properly utilize the advantages of bilateral power supply while reducing the impact on the power grid and users and increasing the efficiency of power consumption.

[0007] Considering the difficulty that the key to bilateral power supply ride-through power is the power returned to the power grid, a bilateral power supply ride-through power utilization technology for electrified railway traction networks is now proposed, which can cancel the electrical phase splitting in the section and eliminate the dead section, while converting the ride-through power into usable power and electrical energy, so that the power returned to the power grid meets the requirements and even becomes zero. Summary of the Invention [Problem to be solved by the invention]

[0008] A first object of the present invention is to provide a bilateral power supply ride-through power utilization system of a traction network that can effectively solve the utilization of ride-through power between substations TSa and TSb, so that the ride-through power returning to the power grid meets specified requirements. [Means for solving the problem]

[0009] The present invention is realized by the following technical means.

[0010] A bilateral power supply ride-through power utilization system for a traction network, comprising: a power converter BCSa and a controller CCa installed in a traction substation TSa; the power converter BCSa is connected to a traction bus TSBa via an AC port Ja; a voltage transformer PTa is installed in the traction bus TSBa; current transformers CTa1 and CTa2 are installed in traction feeders Fa1 and Fa2, respectively; and measurement terminals of the voltage transformer PTa, current transformer CTa1, and current transformer CTa2 are connected to input terminals of the controller CCa; The power converter BCSb and the controller CCb are further provided in the traction substation TSb, the power converter BCSb is connected to the traction bus TSBb via the AC port Jb, a voltage transformer PTb is provided in the traction bus TSBb, and a current transformer CTb1 and a current transformer CTb2 are provided in the traction feeder Fb1 and the traction feeder Fb2, respectively, and measurement terminals of the voltage transformer PTb, the current transformer CTb1, and the current transformer CTb2 are connected to input terminals of the controller CCb; The controllers CCa and CCb connect the OFL via optical fiber to exchange information, where the traction network OCS between the traction substation TSa and the traction substation TSb adopts bilateral power supply, the controller CCa is used to obtain power information of the substation TSa in real time, the controller CCb is used to obtain power information of the substation TSb in real time, and the controllers CCa and CCb respectively control the power converters BCSa and BCSb according to the information exchange results to utilize the ride-through power, so that the ride-through power returning from the traction substation TSa or the traction substation TSb to the power grid meets predetermined requirements.

[0011] Furthermore, the traction substation TSa adopts an in-phase power supply, and the traction bus TSBa of the traction substation TSa feeds the traction network OCS via the traction feeder Fa1 and feeds the traction network OCSa of the left adjacent feeder section via the traction feeder Fa2, and the traction network OCS and the traction network OCSa of the left adjacent feeder section are connected via a sectionalizer.

[0012] Furthermore, the traction substation TSb adopts in-phase power supply, and the traction bus TSBb of the traction substation TSb feeds power to the traction network OCS via the traction feeder Fb1 and to the traction network OCSb of the right adjacent feeder section via the traction feeder Fb2, and the traction network OCS and the traction network OCSb of the right adjacent feeder section are connected via a sectionalizer.

[0013] Furthermore, the power conversion device BCSa includes a rectifier device ADCa and an inverter device DACa, the DC side of the rectifier device ADCa is connected to the DC sides of the energy storage device ESDa and the inverter device DACa via a common DC bus DCBa, the three-phase AC side of the inverter device DACa is connected to the distribution system bus DSBa of the traction substation TSa, and the output terminal of the controller CCa is connected to the control terminal of the power conversion device BCSa.

[0014] Furthermore, the power conversion device BCSb includes a rectifier device ADCb and an inverter device DACb, the DC side of the rectifier device ADCb is connected to the DC sides of the energy storage device ESDb and the inverter device DACb via a common DC bus DCBb, the three-phase AC side of the inverter device DACb is connected to the power distribution system bus DSBb of the traction substation TSb, and the output terminal of the controller CCb is connected to the control terminal of the power conversion device BCSb.

[0015] Another object of the present invention is to provide The controller CCa and the controller CCb respectively obtain real-time power information of the traction substation TSa and the traction substation TSb; the controller CCa and the controller CCb exchange information according to the acquired real-time power information; The controller CCa controls the power converter BCSa to utilize the ride-through power according to the information exchange result, and the controller CCb controls the power converter BCSb to utilize the ride-through power according to the information exchange result, so that the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement.

[0016] Furthermore, both the traction substation TSa and the traction substation TSb adopt in-phase power supply, and in the control method, The step of the controller CCa obtaining real-time power information of the traction substation TSa includes the steps of: the controller CCa detecting the voltage Ua of the traction bus TSBa, the current Ia1 of the traction feeder Fa1, and the current Ia2 of the traction feeder Fa2 in real time; the controller CCa calculating the active power Pca supplied from the traction substation TSa to the traction network OCS according to the voltage Ua of the traction bus TSBa and the current Ia1 of the traction feeder Fa1; and the controller CCa calculating the active power Pcaa supplied from the traction substation TSa to the left adjacent feeder traction network OCSa according to the voltage Ua of the traction bus TSBa and the current Ia2 of the traction feeder Fa2; The step of the controller CCb obtaining real-time power information of the substation TSb includes the steps of the controller CCb detecting the voltage Ub of the traction bus TSBb, the current Ib1 of the traction feeder Fb1, and the current Ib2 of the traction feeder Fb2 in real time, the controller CCb calculating the active power Pcb supplied from the traction substation TSb to the traction network OCS according to the voltage Ub of the traction bus TSBb and the current Ib1 of the traction feeder Fb1, and the controller CCb calculating the active power Pcbb supplied from the traction substation TSb to the right-side adjacent feeder traction network OCSb according to the voltage Ub of the traction bus TSBb and the current Ib2 of the traction feeder Fb2; The power flowing from the traction substation to the traction network is positive, and the power flowing from the traction network to the traction substation is negative.

[0017] Furthermore, the step of the controller CCa and the controller CCb exchanging information according to the real-time power information respectively acquired includes the step of the controller CCa sending active power Pca and active power Pcaa data to the controller CCb to the OFL via the optical fiber, and the step of the controller CCb sending active power Pcb and active power Pcbb data to the controller CCa to the OFL via the optical fiber.

[0018] Furthermore, the steps of the controller CCa controlling the power converter BCSa to utilize the ride-through power according to the information exchange result, and the controller CCb controlling the power converter BCSb to utilize the ride-through power according to the information exchange result, whereby the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement, When Pca>0, Pcb<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers flowing from the traction feeder Fa1 to the traction feeder Fb1; at this time, if the active power Pca≧Pcbb≧0, the controller CCb controls the power converter BCSb to supply power to the power distribution system bus DSBb or makes the energy storage device ESDb operate in an energy storage state; when the sum of the two powers=Pca−Pcbb, the controller CCa controls the power converter BCSa to be on standby; when the active power Pcbb≧Pca, the controller CCb controls the power converter BCSb to be on standby, and at the same time the controller CCa controls the power converter BCSa to be on standby; When Pcb>0, Pca<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers that flow from the traction feeder Fb1 to the traction feeder Fa1. At this time, if the active power Pcb≧Pcaa≧0, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or makes the energy storage device ESDa operate in an energy storage state. If the sum of the two powers=Pcb−Pcaa, the controller CCb controls the power converter BCSb to be on standby. If the active power Pcaa≧Pcb, the controller CCa controls the power converter BCSa to be on standby, and at the same time, the controller CCb controls the power converter BCSb to be on standby. and when |Pca+Pcb|>0, Pca>0, Pcb>0 and the controllers CCa and CCb determine that the traction network OCS is in a traction operating condition, the controller CCa controls the power converter BCSa to operate the energy storage device ESDa in a discharging state, and the discharge power of the energy storage device ESDa is equal to or less than Pca, and at the same time, the controller CCb controls the power converter BCSb to operate the energy storage device ESDb in a discharging state, and the discharge power of the energy storage device ESDb is equal to or less than Pcb.

[0019] Furthermore, the steps of the controller CCa controlling the power converter BCSa to utilize the ride-through power according to the information exchange result, and the controller CCb controlling the power converter BCSb to utilize the ride-through power according to the information exchange result, whereby the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement, If Pca<0 and Pcb<0, and the controllers CCa and CCb determine that the traction network OCS is in a braking operating condition, then: if Pcaa<0, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of both powers=|Pca|+|Pcaa|, if Pcaa>0 and Pcaa<|Pca|, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of both powers=|Pca|-|Pcaa|, if Pcaa>0 and Pcaa≧|Pca|, the controller CCa controls the power converter BCSa to put it on standby; If Pcbb<0, the controller CCb controls the power conversion device BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and the sum of both powers=|Pcb|+|Pcbb|, and if Pcbb>0 and Pcbb<|Pcb|, the controller CCb controls the power conversion device BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and the sum of both powers=|Pcb|-|Pcbb|, and if Pcbb>0 and Pcbb≧|Pcb|, the controller CCb controls the power conversion device BCSb to standby.

[0020] The working principle of this invention is as follows. Typically, a bilateral traction network forms a parallel structure with the power grid. When the traction network is unloaded, a portion of the power transmitted from the power grid flows through the traction network. This power is called ride-through power (the corresponding current is called balanced current). Charging current and charging power are also generated in the distributed capacitance of the transmission line and traction network. Ride-through power flows along the traction network and is a vertical component, while charging power, like load, is a horizontal component. When the traction network is unloaded, simply selecting the active component for measuring ride-through power can reflect the ride-through situation. It can be measured at the traction substation's siding, the traction feeder, or any convenient location in the traction network. The in-phase power supply of the traction substation and the bilateral power supply of the traction network are equivalent to an extension of the power supply arm. This allows the traction train, among the accompanying vehicles, to more efficiently absorb the regenerative power of the braking train, ultimately significantly reducing, or even eliminating, the regenerative power returning to the power grid. If the traction load generates a large lateral component equal to or greater than the value of the ride-through power returning to the grid, it indicates only the lateral component effect, i.e., the equivalent traction operating condition.If the load on the traction network is in the regenerative braking operating condition, the generated regenerative braking energy is first dissipated in the adjacent feeder section, and the excess regenerative energy is fed back to the grid via the traction substation.The voltage and current information of the two traction substations for bilateral power supply is used to determine the operating conditions of the bilateral power supply section traction network, and under the no-load operating condition, the power converter stores the ride-through power in the energy storage device or converts it into the substation's own power consumption system, so that the ride-through power returning to the power grid meets the specified requirements; under the traction operating condition (or equivalent traction operating condition), the energy storage device releases energy for use by the train; under the regenerative braking operating condition (when there is also ride-through power), the power converter stores both the regenerative power and the ride-through power in the energy storage device or converts it into the substation's own power consumption system, so that the power returning to the power grid meets the specified requirements. [Effects of the Invention]

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Without changing the power grid's power supply structure to railways, it utilizes ride-through power from the traction network, eliminating the negative impact that ride-through power has on the power grid and users, and fully utilizing the benefits of bilateral power supply. 2. Implementing bilateral power supply based on in-phase power supply is more advantageous in utilizing the regenerative energy of the power supply arm, increasing the direct utilization rate of regenerative braking energy, and in normal cases, the regenerative power and electrical energy returning to the power grid can meet the specified requirements and even become zero. 3. The power conversion device can be connected to the traction substation's energy storage device and power distribution system to supply power, and in addition to utilizing ride-through power, it can also utilize surplus regenerative braking electrical energy. 4. The technology is advanced, reliable, and easy to implement.

[0022] The drawings are used to provide a further understanding of embodiments of the invention, constitute a part of the specification, and, together with the following detailed description, are used to explain, but not to limit, embodiments of the invention. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of a connection relationship between a bilateral power supply system of the present invention and a power grid. [Figure 2] 1 is a structural schematic diagram of the present invention. [Figure 3] 1 is a structural schematic diagram of a power converter BCSa according to the present invention. [Figure 4] 1 is a structural schematic diagram of a power conversion device BCSb according to the present invention. [Figure 5] 3 is a flowchart of a control method of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described below with reference to the drawings and specific embodiments.

[0025] Example 1 Figure 1 shows a single-line diagram of the bilateral power feed and its connection to the power grid. The bilateral power feed traction network OCS forms a parallel structure with the power grid G via traction substations TSa and TSb on both sides. According to the parallel shunt principle, bilateral power feed generates a current component parallel to the power grid G in the traction network OCS, known as a balancing current. This generates ride-through power and affects the railway's electricity bill. The primary-side electricity bill for the two bilateral power feed substations can be effectively resolved by adopting a reverse metering method for backfeed power. Not metering backfeed power or forward metering backfeed power would result in additional burdens on the railway.

[0026] Therefore, as shown in FIG. 2, this embodiment provides a bilateral power supply ride-through power utilization system for a traction network, including a power converter BCSa and a controller CCa installed in a traction substation TSa, the power converter BCSa is connected to a traction bus TSBa via an AC port Ja, a voltage transformer PTa is installed in the traction bus TSBa, a current transformer CTa1 and a current transformer CTa2 are installed in the traction feeder Fa1 and the traction feeder Fa2, respectively, and measurement terminals of the voltage transformer PTa, the current transformer CTa1 and the current transformer CTa2 are connected to input terminals of the controller CCa; The power converter BCSb and the controller CCb are further provided in the traction substation TSb, the power converter BCSb is connected to the traction bus TSBb via the AC port Jb, a voltage transformer PTb is provided in the traction bus TSBb, and a current transformer CTb1 and a current transformer CTb2 are provided in the traction feeder Fb1 and the traction feeder Fb2, respectively, and measurement terminals of the voltage transformer PTb, the current transformer CTb1, and the current transformer CTb2 are connected to input terminals of the controller CCb; The controllers CCa and CCb connect the OFL via optical fiber to exchange information, the traction network OCS between the traction substation TSa and the traction substation TSb adopts bilateral power supply, the controller CCa is used to obtain power information of the substation TSa in real time, the controller CCb is used to obtain power information of the substation TSb in real time, and the controllers CCa and CCb control the power converters BCSa and BCSb respectively according to the information exchange results to utilize the ride-through power, so that the ride-through power returning from the traction substation TSa or the traction substation TSb to the power grid meets specified requirements.

[0027] In this application scenario, the electrical phase split between traction substation TSa and traction substation TSb is canceled, i.e., the traction network OCS between traction substation TSa and traction substation TSb adopts bilateral power supply. Also, as described in the background art, it is necessary to reduce the output voltage difference between the two traction substations in a bilateral power supply by connecting a reactor in series with the secondary side of the traction transformer of the traction substation or by adding a voltage compensator to the traction substation to achieve voltage phase compensation. However, these two measures are not required in this embodiment. That is, this embodiment may or may not adopt these two measures. The core of this embodiment is the use of ride-through power, or power returning to the traction substation where ride-through power exists. Rather than suppressing the occurrence of ride-through power, the focus is on how to respond after ride-through power occurs, which is key to distinguishing this embodiment from the prior art. Furthermore, this embodiment is based on the technical concept of utilizing ride-through power, and under actual operating conditions, regenerative power generated when a train brakes may return to the traction substation together with the ride-through power that is originally present. Therefore, the use of ride-through power in this embodiment may also refer to the use of power that returns to the traction substation, including ride-through power. By utilizing ride-through power, the ride-through power that returns from the traction substation TSa to the power grid or the ride-through power that returns from the traction substation TSb to the power grid meets specified requirements, and further, the adverse effects of ride-through power on the power grid and users are eliminated, fully demonstrating the benefits of bilateral power supply.

[0028] Preferably, the traction substation TSa in this embodiment adopts in-phase power supply, and the traction bus TSBa of the traction substation TSa feeds the traction network OCS via the traction feeder Fa1 and feeds the traction network OCSa of the left adjacent feeder section via the traction feeder Fa2, and the traction network OCS and the traction network OCSa of the left adjacent feeder section are connected via a sectionalizer.

[0029] Here, if substation TSa adopts in-phase power supply technology, the power supply arm will be extended, allowing the traction train among the accompanying vehicles to more efficiently absorb the regenerative power of the braking train, increasing the direct utilization rate of regenerative braking energy and ultimately significantly reducing, or even eliminating, the regenerative power returned to the power grid. To facilitate maintenance, this embodiment installs an electrical section in the traction network of traction substation TSa, i.e., between the traction network OCS and the left-side adjacent feeder traction network OCSa. The installation of the electrical section, on the one hand, can be used in conjunction with sectioning measurement, control, and protection technology to facilitate inspection and maintenance without train power outages, and on the other hand, can be combined with the electrical section installed in substation TSb to detect and analyze the operating conditions of the traction network OCS (including detecting and analyzing whether the traction network OCS is unloaded; the power returned to the substation when unloaded is referred to as ride-through power; see Example 2 for a detailed analysis).

[0030] Preferably, the traction substation TSb in this embodiment adopts in-phase power supply, and the traction bus TSBb of the traction substation TSb feeds power to the traction network OCS via the traction feeder Fb1 and feeds power to the right adjacent feeder section traction network OCSb via the traction feeder Fb2, and the traction network OCS and the right adjacent feeder section traction network OCSb are connected via a sectionalizer.

[0031] Here, if substation TSb adopts in-phase power supply technology, the power supply arm will be extended, allowing the traction train among the accompanying vehicles to more efficiently absorb the regenerative power of the braking train, increasing the direct utilization rate of regenerative braking energy and ultimately significantly reducing, or even eliminating, the regenerative power returned to the power grid. To facilitate maintenance, this embodiment also installs an electrical section in the traction network of substation TSb, i.e., between the traction network OCS and the traction network OCSb, the right-side adjacent power supply section. The installation of the electrical section, on the one hand, can be used in conjunction with sectioning measurement, control, and protection technology to facilitate inspection and maintenance without causing train power outages, and on the other hand, can be combined with the electrical section installed in traction substation TSa to detect and analyze the operating conditions of the traction network OCS (including detecting and analyzing whether the traction network OCS is unloaded; the power returned to the substation when unloaded is referred to as ride-through power; see Example 2 for a detailed analysis).

[0032] Preferably, as shown in FIG. 3 , the power conversion device BCSa includes a rectifier device ADCa and an inverter device DACa, the DC side of the rectifier device ADCa is connected to the DC sides of the energy storage device ESDa and the inverter device DACa via a common DC bus DCBa, the three-phase AC side of the inverter device DACa is connected to the distribution system bus DSBa of the traction substation TSa, and the output terminals of the controller CCa are connected to the control terminals of the power conversion device BCSa.

[0033] Here, when ride-through power or back-transmission power including the ride-through power flows to the traction substation TSa, the controller CCa may control the energy storage device ESDa to store the ride-through power or back-transmission power including the ride-through power flowing to the traction substation TSa, or control the ride-through power or back-transmission power including the ride-through power flowing to the traction substation TSa to flow to the distribution system bus DSBa so that it can be used by related electrical devices in the distribution system, thereby ensuring that the ride-through power returning from the substation TSa to the power grid meets predetermined requirements.

[0034] Preferably, as shown in FIG. 4, the power conversion device BCSb includes a rectifier device ADCb and an inverter device DACb, the DC side of the rectifier device ADCb is connected to the DC sides of the energy storage device ESDb and the inverter device DACb via a common DC bus DCBb, the three-phase AC side of the inverter device DACb is connected to the power distribution system bus DSBb of the traction substation TSb, and the output terminal of the controller CCb is connected to the control terminal of the power conversion device BCSb.

[0035] Here, when ride-through power or back-transmission power including the ride-through power flows to substation TSb, controller CCb may control energy storage device ESDb to store the ride-through power or back-transmission power including the ride-through power flowing to substation TSb, or control the ride-through power or back-transmission power including the ride-through power flowing to substation TSb to flow to the power distribution system bus DSBb so that it can be used by related electrical devices in the power distribution system, thereby ensuring that the ride-through power returning from substation TSb to the power grid meets predetermined requirements.

[0036] As described above, the bilateral power supply ride-through power utilization system of the traction network according to the embodiment of the present invention has at least the following advantages.

[0037] 1. Without changing the power grid's power supply structure to railways, it utilizes ride-through power from the traction network, eliminating the negative impact that ride-through power has on the power grid and users, and fully utilizing the benefits of bilateral power supply. 2. Implementing bilateral power supply based on in-phase power supply is more advantageous in utilizing the regenerative energy of the power supply arm, increasing the direct utilization rate of regenerative braking energy, and in normal cases, the regenerative power and electrical energy returning to the power grid can meet the specified requirements and even become zero. 3. The power conversion device can be connected to the traction substation's energy storage device and power distribution system to supply power, and in addition to utilizing ride-through power, it can also utilize surplus regenerative braking electrical energy. 4. The technology is advanced, reliable, and easy to implement.

[0038] Example 2 As shown in FIG. 5, this embodiment provides a control method based on the bilateral power supply ride-through power utilization system of the traction network provided in the first embodiment, Step S100: the controller CCa and the controller CCb obtain real-time power information of the traction substation TSa and the traction substation TSb, respectively; Step S200: the controllers CCa and CCb exchange information according to the acquired real-time power information; The controller CCa controls the power converter BCSa to utilize the ride-through power according to the information exchange result, and the controller CCb controls the power converter BCSb to utilize the ride-through power according to the information exchange result, thereby ensuring that the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement.

[0039] Preferably, both the traction substation TSa and the traction substation TSb adopt an in-phase power supply, and in the method, Step S100 in which the controllers CCa and CCb respectively obtain real-time power information of the traction substation TSa and the traction substation TSb includes the steps of: the controller CCa detecting the voltage Ua of the traction bus TSBa, the current Ia1 of the traction feeder Fa1, and the current Ia2 of the traction feeder Fa2 in real time; the controller CCa calculating the active power Pca supplied from the traction substation TSa to the traction network OCS according to the voltage Ua of the traction bus TSBa and the current Ia1 of the traction feeder Fa1; and the controller CCa calculating the active power Pcaa supplied from the traction substation TSa to the left adjacent feeder traction network OCSa according to the voltage Ua of the traction bus TSBa and the current Ia2 of the traction feeder Fa2. the controller CCb detects the voltage Ub of the traction bus TSBb, the current Ib1 of the traction feeder Fb1, and the current Ib2 of the traction feeder Fb2 in real time, the controller CCb calculates the active power Pcb supplied from the traction substation TSb to the traction network OCS according to the voltage Ub of the traction bus TSBb and the current Ib1 of the traction feeder Fb1, and the controller CCb calculates the active power Pcbb supplied from the traction substation TSb to the right-side adjacent feeder traction network OCSb according to the voltage Ub of the traction bus TSBb and the current Ib2 of the traction feeder Fb2, The power flowing from the traction substation to the traction network is positive, and the power flowing from the traction network to the traction substation is negative.

[0040] Here, the power flowing from the traction substation to the traction network being positive does not only mean that only the power flowing from traction substation TSa to traction network OCS or the left adjacent feeder section traction network OCSa is positive, but also means that the power flowing from traction substation TSb to traction network OCS or the right adjacent feeder section traction network OCSb is positive. The power flowing from the traction network to the traction substation being negative does not only mean that the power flowing from traction network OCS or the left adjacent feeder section traction network OCSa to traction substation TSa is negative, but also means that the power flowing from traction network OCS or the right adjacent feeder section traction network OCSb to traction substation TSb is negative.

[0041] Preferably, the step S200 of the controllers CCa and CCb exchanging information according to the power information respectively acquired in real time includes: the step of the controller CCa and the controller CCb exchanging information according to the real-time power information respectively acquired by the controllers CCa and CCb including the step of the controller CCa transmitting active power Pca and active power Pcaa data to the controller CCb via the optical fiber to the OFL, and the controller CCb transmitting active power Pcb and active power Pcbb data to the controller CCa via the optical fiber to the OFL.

[0042] Preferably, the step S300 is performed by the controller CCa controlling the power converter BCSa in accordance with the information exchange result to utilize the ride-through power, and the controller CCb controlling the power converter BCSb in accordance with the information exchange result to utilize the ride-through power, so that the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement. Step S301: when Pca>0, Pcb<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers that flow from the traction feeder Fa1 to the traction feeder Fb1; at this time, if the active power Pca≧Pcbb≧0, the controller CCb controls the power converter BCSb to supply power to the power distribution system bus DSBb or makes the energy storage device ESDb operate in an energy storage state; when the sum of the two powers=Pca−Pcbb, the controller CCa controls the power converter BCSa to be on standby; when the active power Pcbb≧Pca, the controller CCb controls the power converter BCSb to be on standby, and at the same time, the controller CCa controls the power converter BCSa to be on standby; Step S302: when Pcb>0, Pca<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers that flow from the traction feeder Fb1 to the traction feeder Fa1, if the active power Pcb≧Pcaa≧0, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and when the sum of the two powers=Pcb−Pcaa, the controller CCb controls the power converter BCSb to be on standby, and when the active power Pcaa≧Pcb, the controller CCa controls the power converter BCSa to be on standby, and the controller CCb controls the power converter BCSb to be on standby; and step S303, if |Pca+Pcb|>0, and Pca>0, Pcb>0, and the controllers CCa and CCb determine that the traction network OCS is in a traction operating condition, the controller CCa controls the power converter BCSa to operate the energy storage device ESDa in a discharging state, and the discharge power of the energy storage device ESDa is ≦Pca, and at the same time, the controller CCb controls the power converter BCSb to operate the energy storage device ESDb in a discharging state, and the discharge power of the energy storage device ESDb is ≦Pcb.

[0043] Preferably, the controller CCa controls the power converter BCSa according to the information exchange result to utilize the ride-through power, and the controller CCb controls the power converter BCSb according to the information exchange result to utilize the ride-through power, so that the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement. The step 300 further includes step S304; Step S304: If Pca<0 and Pcb<0, and the controllers CCa and CCb determine that the traction network OCS is in a braking operating condition, then: In step S304-1, if Pcaa<0, the controller CCa controls the power conversion device BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of the powers of both=|Pca|+|Pcaa|, and if Pcaa>0 and Pcaa<|Pca|, the controller CCa controls the power conversion device BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of the powers of both=|Pca|-|Pcaa|, and if Pcaa>0 and Pcaa≧|Pca|, the controller CCa controls the power conversion device BCSa to put it on standby; In step S304-2, if Pcbb<0, the controller CCb controls the power conversion device BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and the sum of the powers of both = |Pcb|+|Pcbb|, and if Pcbb>0 and Pcbb<|Pcb|, the controller CCb controls the power conversion device BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and the sum of the powers of both = |Pcb|-|Pcbb|, and if Pcbb>0 and Pcbb≧|Pcb|, the controller CCb controls the power conversion device BCSb to standby.

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

[0045] 300 steps S100 Step S200 Step S300 Step S301 Step S302 Step S303 Step S304 Step S304-1 Step S304-2 Step ADCa rectifier ADCb rectifier BCSa power converter BCSb power converter CCa Controller CCb Controller CTa1 Current Transformer CTa2 current transformer CTb1 Current Transformer CTb2 current transformer DACa inverter device DACb inverter device DCBa Common DC Bus DCBb Common DC Bus DSBa Power Distribution System Bus DSBb Power Distribution System Bus ESDa Energy Storage Device ESDb Energy Storage Device Fa1 Traction Feeder Fa2 Traction Feeder Fb1 Traction Feeder Fb2 Traction Feeder G power grid Ia1 current Ia2 current Ib1 current Ib2 current Ja AC port Jb AC port OCS Traction Network OCS Bilateral Power Supply Traction Network OCSa Left adjacent feeder section traction network OCSb Right Adjacent Feeder Section Traction Network Pca active power Pcaa active power PCB active power Pcbb active power PTa voltage transformer PTb voltage transformer TSa Substation TSa Traction Substation TSb substation TSb Traction Substation TSBa Traction Bus TSBb Traction Bus Ua voltage Ub voltage

Claims

1. A bilateral power feed ride-through power utilization system for a traction network, comprising: The power converter includes a power conversion device BCSa and a controller CCa installed in a traction substation TSa, the power conversion device BCSa is connected to a traction bus TSBa via an AC port Ja, a voltage transformer PTa is installed in the traction bus TSBa, a current transformer CTa1 and a current transformer CTa2 are installed in a traction feeder Fa1 and a traction feeder Fa2, respectively, and measurement terminals of the voltage transformer PTa, the current transformer CTa1 and the current transformer CTa2 are connected to input terminals of the controller CCa, The power converter BCSb and the controller CCb are further provided in the traction substation TSb, the power converter BCSb is connected to a traction bus TSBb via an AC port Jb, a voltage transformer PTb is provided in the traction bus TSBb, and a current transformer CTb1 and a current transformer CTb2 are provided in the traction feeder Fb1 and the traction feeder Fb2, respectively, and measurement terminals of the voltage transformer PTb, the current transformer CTb1, and the current transformer CTb2 are connected to input terminals of the controller CCb; the controllers CCa and CCb connect the OFL via optical fiber to exchange information, the traction network OCS between the traction substation TSa and the traction substation TSb adopts bilateral power supply, the controller CCa is used to acquire power information of the substation TSa in real time, the controller CCb is used to acquire power information of the substation TSb in real time, and the controllers CCa and CCb control the power conversion devices BCSa and BCSb respectively according to the information exchange result to utilize the ride-through power, so that the ride-through power returning from the traction substation TSa or the traction substation TSb to the power grid meets predetermined requirements, the bilateral power supply ride-through power utilization system for a traction network is characterized in that:

2. 2. The traction network bilateral feed ride-through power utilization system according to claim 1, wherein the traction substation TSa adopts an in-phase power supply, the traction bus TSBa of the traction substation TSa supplies power to the traction network OCS via a traction feeder Fa1, and supplies power to the left adjacent feeder traction network OCSa via a traction feeder Fa2, and the traction network OCS and the left adjacent feeder traction network OCSa are connected via a sectionalizer.

3. 2. The traction network bilateral feed ride-through power utilization system according to claim 1, wherein the traction substation TSb adopts an in-phase power supply, the traction bus TSBb of the traction substation TSb supplies power to the traction network OCS via a traction feeder Fb1 and to the right-side adjacent feeder traction network OCSb via a traction feeder Fb2, and the traction network OCS and the right-side adjacent feeder traction network OCSb are connected via a sectionalizer.

4. 2. The bilateral power supply ride-through power utilization system of a traction network according to claim 1, wherein the power conversion device BCSa includes a rectifier ADCa and an inverter DACa, a DC side of the rectifier ADCa is connected to the DC sides of the energy storage device ESDa and the inverter DACa via a common DC bus DCBa, a three-phase AC side of the inverter DACa is connected to a power distribution system bus DSBa of the traction substation TSa, and an output terminal of the controller CCa is connected to a control terminal of the power conversion device BCSa.

5. 2. The bilateral power supply ride-through power utilization system of a traction network according to claim 1, wherein the power conversion device BCSb includes a rectifier ADCb and an inverter DACb, a DC side of the rectifier ADCb is connected to the DC sides of the energy storage device ESDb and the inverter DACb via a common DC bus DCBb, a three-phase AC side of the inverter DACb is connected to a power distribution system bus DSBb of the traction substation TSb, and an output terminal of the controller CCb is connected to a control terminal of the power conversion device BCSb.

6. A control method based on a bilateral power feed ride-through power utilization system of a traction network according to any one of claims 1 to 5, comprising: The controller CCa and the controller CCb respectively obtain real-time power information of the traction substation TSa and the traction substation TSb; the controller CCa and the controller CCb exchanging information according to the acquired real-time power information; a step of the controller CCa controlling the power conversion device BCSa to utilize the ride-through power according to the information exchange result, and the controller CCb controlling the power conversion device BCSb to utilize the ride-through power according to the information exchange result, so that the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement.

7. The traction substation TSa and the traction substation TSb both adopt in-phase power supply, and in the control method, The step of the controller CCa obtaining real-time power information of the traction substation TSa includes the steps of: the controller CCa detecting the voltage Ua of the traction bus TSBa, the current Ia1 of the traction feeder Fa1, and the current Ia2 of the traction feeder Fa2 in real time; the controller CCa calculating the active power Pca supplied from the traction substation TSa to the traction network OCS according to the voltage Ua of the traction bus TSBa and the current Ia1 of the traction feeder Fa1; and the controller CCa calculating the active power Pcaa supplied from the traction substation TSa to the left adjacent feeder traction network OCSa according to the voltage Ua of the traction bus TSBa and the current Ia2 of the traction feeder Fa2; The step of the controller CCb obtaining real-time power information of the substation TSb includes the steps of the controller CCb detecting the voltage Ub of the traction bus TSBb, the current Ib1 of the traction feeder Fb1, and the current Ib2 of the traction feeder Fb2 in real time, the controller CCb calculating the active power Pcb supplied from the traction substation TSb to the traction network OCS according to the voltage Ub of the traction bus TSBb and the current Ib1 of the traction feeder Fb1, and the controller CCb calculating the active power Pcbb supplied from the traction substation TSb to the right-side adjacent feeder traction network OCSb according to the voltage Ub of the traction bus TSBb and the current Ib2 of the traction feeder Fb2; 7. The method according to claim 6, wherein the power flowing from the traction substation to the traction network is positive and the power flowing from the traction network to the traction substation is negative.

8. 8. The control method according to claim 7, wherein the step of the controllers CCa and CCb exchanging information according to the acquired real-time power information includes the step of the controller CCa transmitting active power Pca and active power Pcaa data to the controller CCb via the optical fiber to the OFL, and the step of the controller CCb transmitting active power Pcb and active power Pcbb data to the controller CCa via the optical fiber to the OFL.

9. The step of the controller CCa controlling the power conversion device BCSa to utilize the ride-through power in accordance with the information exchange result, and the controller CCb controlling the power conversion device BCSb to utilize the ride-through power in accordance with the information exchange result, whereby the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement, When Pca>0, Pcb<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers that flow from the traction feeder Fa1 to the traction feeder Fb1; at this time, if the active power Pca≧Pcbb≧0, the controller CCb controls the power converter BCSb to supply power to the power distribution system bus DSBb, or makes the energy storage device ESDb operate in an energy storage state; when the sum of the two powers=Pca−Pcbb, simultaneously, the controller CCa controls the power converter BCSa to be on standby; when the active power Pcbb≧Pca, the controller CCb controls the power converter BCSb to be on standby, and simultaneously, the controller CCa controls the power converter BCSa to be on standby; When Pcb>0, Pca<0 and Pca+Pcb=0, the controllers CCa and CCb determine that the traction network OCS is in a no-load operating condition, and the active powers Pca and Pcb are ride-through powers that flow from the traction feeder Fb1 to the traction feeder Fa1; at this time, if the active power Pcb≧Pcaa≧0, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa, or makes the energy storage device ESDa operate in an energy storage state; when the sum of the two powers=Pcb−Pcaa, simultaneously, the controller CCb controls the power converter BCSb to be on standby; when the active power Pcaa≧Pcb, the controller CCa controls the power converter BCSa to be on standby, and simultaneously, the controller CCb controls the power converter BCSb to be on standby; 7. The control method of claim 6, comprising: when |Pca+Pcb|>0 and Pca>0, Pcb>0, and the controllers CCa and CCb determine that the traction network OCS is in a traction operating condition, the controller CCa controls the power converter BCSa to operate the energy storage device ESDa in a discharging state, and the discharge power of the energy storage device ESDa≦Pca; and at the same time, the controller CCb controls the power converter BCSb to operate the energy storage device ESDb in a discharging state, and the discharge power of the energy storage device ESDb≦Pcb.

10. The step of the controller CCa controlling the power conversion device BCSa to utilize the ride-through power in accordance with the information exchange result, and the controller CCb controlling the power conversion device BCSb to utilize the ride-through power in accordance with the information exchange result, whereby the ride-through power returning from the traction substation TSa to the power grid or the ride-through power returning from the traction substation TSb to the power grid satisfies a predetermined requirement, If Pca<0 and Pcb<0, and the controllers CCa and CCb determine that the traction network OCS is in a braking operating condition, then: if Pcaa<0, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of both powers=|Pca|+|Pcaa|, if Pcaa>0 and Pcaa<|Pca|, the controller CCa controls the power converter BCSa to supply power to the power distribution system bus DSBa or operates the energy storage device ESDa in an energy storage state, and the sum of both powers=|Pca|-|Pcaa|, if Pcaa>0 and Pcaa≧|Pca|, the controller CCa controls the power converter BCSa to put it into standby; 10. The control method of claim 9, further comprising: if Pcbb<0, the controller CCb controls the power converter BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and a sum of both powers=|Pcb|+|Pcbb|; if Pcbb>0 and Pcbb<|Pcb|, the controller CCb controls the power converter BCSb to supply power to the power distribution system bus DSBb or operates the energy storage device ESDb in an energy storage state, and a sum of both powers=|Pcb|-|Pcbb|; if Pcbb>0 and Pcbb≧|Pcb|, the controller CCb controls the power converter BCSb to put into standby.

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