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 a traction network. [Background technology]

[0003] The electrical splitting of electrified railways is a weak point in the entire traction power supply system, and the neutral section of the electrical splitting forms a dead section, which causes power supply interruption. The dead section of the neutral section is generally only a few tens of meters, but the blackout distance when controlling the train to pass through the automatic splitting phase can reach more than 500 meters, which severely restricts the good operation of the train and even causes the train to stop on the slope when going uphill. The bilateral power supply of electrified railways can eliminate the electrical splitting in the section, eliminate the dead section here, ensure the continuous power supply of the train, and at the same time eliminate the risk of excessive splitting. Bilateral power supply has the advantages of high power supply reliability, good voltage level of the power grid, high power supply capacity, and small power loss.

[0004] Usually, a bilateral power supply traction network forms a parallel structure with the power grid through the traction substations on both sides, and when the traction network is unloaded, power and current flow through the traction network, and the corresponding power is called the ride-through power (the corresponding current is called the balanced current). At this time, the ride-through power flows in from the traction substation on one side and flows out from the traction substation on the other side, that is, when the ride-through power flows from the power grid to the traction substation of the traction network, it is in a load (power consumption) state, and when the 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 has changed the structure of the power grid, two important technical problems need to be solved to implement bilateral power supply.

[0005] The first issue is the issue of relay protection of the power grid and traction network, which requires that relay protection have a wider protection scope and have the function of tripping the traction network in conjunction with the power grid to cut off the transmission of power flow when the power grid fails, etc. This can be perfectly solved by arranging transmission line protection in the power grid and arranging hierarchical protection in the traction network.

[0006] The second problem is the impact of ride-through power on the power grid and the problem of 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 in the reverse direction, i.e., treated as power generation and offset with the power consumption of another traction substation, users will not suffer economic loss. If the backfeed power is not metered or is metered forward when the ride-through power is returned to the power grid, it will cause economic loss to users. In such cases, it is necessary to study how bilateral power supply can reduce ride-through power or how to utilize ride-through power to properly exert 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 at the same time 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; 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 included, which are installed 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 installed in the traction bus TSBb, a current transformer CTb1 and a current transformer CTb2 are installed 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 controller CCa and the controller CCb connect the OFL through 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 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, and the controller CCa and the controller CCb respectively control the power converter BCSa and 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 or the traction substation TSb to the power grid meets a predetermined requirement.

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

[0012] Furthermore, the traction substation TSb adopts in-phase power supply, 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-side adjacent feeder section traction network OCSb via the traction feeder Fb2, and the traction network OCS and the right-side adjacent feeder section traction network OCSb 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 real-time power information respectively acquired; The controller CCa controls the power conversion device BCSa to utilize the ride-through power in accordance with the information exchange result, and the controller CCb controls the power conversion device BCSb to utilize the ride-through power in accordance with the information exchange result, thereby allowing 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 to satisfy 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 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 for the OFL via the optical fiber, and the controller CCb sending active power Pcb and active power Pcbb data to the controller CCa for the OFL via the optical fiber.

[0018] Further, the step of the controller CCa controlling the power converter BCSa according to the information exchange result to utilize the ride-through power, and the controller CCb controlling the power converter BCSb according to the information exchange result to utilize the ride-through power, thereby 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 satisfying a predetermined requirement, 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 power Pca and the active power 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; and, if the sum of the two powers=Pca-Pcbb, at the same time, the controller CCa controls the power converter BCSb to be on standby; and, if the active power Pcbb≧Pca, the controller CCb controls the power converter BCSb to be on standby, at the same time, the controller CCa controls the power converter BCSa to be on standby; 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 power Pca and the active power Pcb are ride-through powers flowing 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 powers of the two is=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 ≦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.

[0019] Further, the step of the controller CCa controlling the power converter BCSa according to the information exchange result to utilize the ride-through power, and the controller CCb controlling the power converter BCSb according to the information exchange result to utilize the ride-through power, thereby 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 satisfying 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 if the sum of the powers of both = |Pca| + |Pcaa|, and 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 if the sum of the powers of both = |Pca| - |Pcaa|, and if Pcaa>0 and Pcaa ≧ |Pca|, the controller CCa controls the power converter BCSa to put it into standby; The method further includes a step of: 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; if 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; if 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 be on standby.

[0020] The working principle of the present invention is as follows. Usually, the bilateral power supply traction network forms a parallel structure with the power grid, and when the traction network is unloaded, a part of the power transmitted from the power grid flows through the traction network, and the corresponding power is called the ride-through power (the corresponding current is called the balanced current). The charging current and charging power are further generated in the transmission line and the distributed capacitance of the traction network. The ride-through power flows along the traction network and belongs to the vertical component, and the charging power is called the horizontal component, similar to the load. When the traction network is unloaded, only the active component to measure the ride-through power is selected, which can reflect the ride-through situation, and can be measured at the feeder line of the traction substation, the traction feeder, and any convenient part of the traction network. The in-phase power supply of the traction substation and the bilateral power supply of the traction network are equivalent to the extension of the power supply arm, and the traction train among the accompanying vehicles can absorb the regenerative power of the braking train with a higher probability, and finally the regenerative power returning to the power grid is greatly reduced, even to zero. If a large lateral component is generated by the traction load and is equal to or greater than the value of the ride-through power returning to the grid, then it indicates only a lateral component effect, i.e., an equivalent traction operating condition. If the load of the traction network is in a regenerative braking operating condition, the regenerative braking energy generated is first dissipated in the adjacent feeder section, and the excess regenerative energy is fed back to the grid via the traction substation.Using the voltage and current information of the two traction substations for bilateral power supply, the operating conditions of the bilateral power supply section traction network are determined, 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 the 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. Effect 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, eliminates the negative impacts that ride-through power has on the power grid and users, and fully realizes the benefits of bilateral power supply. 2. Implementing bilateral power supply on the basis of in-phase power supply is more advantageous in utilizing the regenerative energy of the power supply arm, and increases the direct utilization rate of the regenerative braking energy. In normal cases, the regenerative power and electrical energy returning to the power grid can meet the specified requirements and even be zero. 3. The power converter can be connected to the energy storage device and distribution system of the traction substation to supply power, and in addition to utilizing the 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 the embodiments of the present invention, constitute a part of the specification, and, together with the following detailed description, are used to explain the embodiments of the present invention but are not intended to limit the embodiments of the present invention. [Brief description of the drawings]

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

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

[0025] Example 1 The single-line schematic diagram of the bilateral power supply and the connection relationship with the power grid is shown in Figure 1. The bilateral power supply traction network OCS forms a parallel structure with the power grid G ​​through the traction substation TSa and the traction substation TSb on both sides. According to the principle of parallel shunt, the bilateral power supply generates a current component parallel to the power grid G ​​in the traction network OCS, which is called the balanced current, and generates ride-through power, which affects the electricity tariff problem of the railway. The electricity tariff on the primary side of the two substations of the bilateral power supply can be well solved by adopting the reverse metering method of the reverse feed power, while not metering the reverse feed power or forward metering the reverse feed power will cause further burden on the railway.

[0026] For this reason, as shown in FIG. 2, the present embodiment provides a bilateral power supply ride-through power utilization system of 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 the measurement terminals of the voltage transformer PTa, the current transformer CTa1 and the current transformer CTa2 are connected to the input terminals of the controller CCa; The power converter BCSb and the controller CCb are further included, which are installed 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 installed in the traction bus TSBb, a current transformer CTb1 and a current transformer CTb2 are installed 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 controller CCa and the controller CCb connect the OFL through 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 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, and the controller CCa and the controller CCb respectively control the power converter BCSa and 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 or the traction substation TSb to the power grid meets a predetermined requirement.

[0027] In the application scenario of this embodiment, the electrical phase split between the traction substation TSa and the traction substation TSb is canceled, that is, the traction network OCS between the traction substation TSa and the 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 of the bilateral power supply by connecting a reactor in series to the secondary side of the traction transformer of the traction substation, or to realize voltage phase compensation by adding a voltage compensator to the traction substation, and these two measures are not essential in this embodiment. That is, this embodiment may adopt these two measures or may not adopt these two measures, and the core of this embodiment is to utilize the ride-through power, or the power that returns to the traction substation where there is ride-through power, and instead of suppressing the generation of ride-through power, it focuses on the response after the ride-through power occurs, which is the key to distinguishing this embodiment from the prior art. In addition, this embodiment is based on the technical concept of using ride-through power, and under actual operating conditions, regenerative power generated when a train brakes may return to the traction substation together with the originally existing ride-through power, so the use of ride-through power in this embodiment may refer to the use of power that returns to the traction substation, including the ride-through power. By using the 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 certain requirements, and further, the adverse effects of the ride-through power on the power grid and users are eliminated, and the advantages of bilateral power supply are fully realized.

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

[0029] Here, if substation TSa adopts the in-phase power supply technology, the power supply arm is extended, and the traction train among the accompanying vehicles can absorb the regenerative power of the braking train with a higher probability, thereby increasing the direct utilization rate of the regenerative braking energy, and finally greatly reducing the regenerative power returning to the power grid, even to zero. In order to facilitate maintenance, this embodiment installs an electrical section in the traction network of traction substation TSa, that is, an electrical section is installed between the traction network OCS and the left adjacent power supply section traction network OCSa. On the one hand, the installation of the electrical section can be used in combination with the sectioning measurement control protection technology to facilitate inspection and maintenance without train power outage, and on the other hand, it can also 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, and the power returning to the substation when unloaded is the ride-through power, and the specific analysis can be referred to embodiment 2).

[0030] Preferably, the traction substation TSb in this embodiment adopts in-phase power supply, 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 through a sectionalizer.

[0031] Here, if substation TSb adopts the in-phase power supply technology, the power supply arm is extended, and the traction train among the accompanying vehicles can absorb the regenerative power of the braking train with a higher probability, thereby increasing the direct utilization rate of the regenerative braking energy, and finally greatly reducing the regenerative power returning to the power grid, even to zero. In order to facilitate maintenance, this embodiment may install an electrical section in the traction network of substation TSb, that is, between the traction network OCS and the right adjacent power supply section traction network OCSb. The installation of the electrical section, on the one hand, can be used in combination with the sectioning measurement control protection technology to facilitate inspection and maintenance without train power outage, 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, and the power returning to the substation when unloaded is the ride-through power, and the specific analysis can be referred to embodiment 2).

[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 terminal of the controller CCa is connected to the control terminal of the power conversion device BCSa.

[0033] Here, when the ride-through power or the 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 the back-transmission power including the ride-through power flowing to the traction substation TSa, or control the ride-through power or the back-transmission power including the ride-through power flowing to the traction substation TSa to flow to the power distribution system bus DSBa so that it can be used by related electrical equipment of the power 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 the ride-through power or the reverse transmission power including the ride-through power flows to the substation TSb, the controller CCb may control the energy storage device ESDb to store the ride-through power or the reverse transmission power including the ride-through power flowing to the substation TSb, or control the ride-through power or the reverse transmission power including the ride-through power flowing to the substation TSb to flow to the power distribution system bus DSBb so that it can be used by related electrical equipment in the power distribution system, thereby making the ride-through power returning from the substation TSb to the power grid meet a predetermined requirement.

[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, eliminates the negative impacts that ride-through power has on the power grid and users, and fully realizes the benefits of bilateral power supply. 2. Implementing bilateral power supply on the basis of in-phase power supply is more advantageous in utilizing the regenerative energy of the power supply arm, and increases the direct utilization rate of the regenerative braking energy. In normal cases, the regenerative power and electrical energy returning to the power grid can meet the specified requirements and even be zero. 3. The power converter can be connected to the energy storage device and distribution system of the traction substation to supply power, and in addition to utilizing the 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 in which the controllers CCa and CCb exchange information according to the acquired real-time power information; The controller CCa controls the power conversion device BCSa to utilize the ride-through power in accordance with the information exchange result, and the controller CCb controls the power conversion device BCSb to utilize the ride-through power in accordance with the information exchange result, thereby causing 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 to satisfy a predetermined requirement.

[0039] Preferably, the traction substation TSa and the traction substation TSb both adopt a common-phase power supply, and in the method, Step S100 in which the controller CCa and the controller 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 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 is positive not only means that only the power flowing from the traction substation TSa to the traction network OCS or the left adjacent feeder section traction network OCSa is positive, but also means that the power flowing from the traction substation TSb to the 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 is negative not only means that the power flowing from the traction network OCS or the left adjacent feeder section traction network OCSa to the traction substation TSa is negative, but also means that the power flowing from the traction network OCS or the right adjacent feeder section traction network OCSb to the traction substation TSb is negative.

[0041] Preferably, the step S200 of exchanging information according to the power information respectively acquired in real time by the controller CCa and the controller CCb includes the following: The step S200 of exchanging information according to the real-time power information respectively acquired by the controller CCa and the controller CCb includes the step of the controller CCa sending active power Pca and active power Pcaa data to the controller CCb via the optical fiber to the OFL, and the controller CCb sending 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 such that 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, thereby satisfying a predetermined requirement for 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. Step S301: 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 power Pca and the active power 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 operates the energy storage device ESDb in an energy storage state. If the sum of the powers of the two is=Pca-Pcbb, the controller CCa controls the power converter BCSa to be on standby. If 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: 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 power Pca and the active power 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 operates the energy storage device ESDa 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 the controller CCb controls the power converter BCSb to be on standby. Step S303 includes: if |Pca+Pcb|>0, and Pca>0, Pcb>0, and the controller CCa and the controller 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 from the traction substation TSa returning to the power grid or the ride-through power from the traction substation TSb returning to the power grid meets 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 if 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 if 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 be 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 if the sum of the powers of both=|Pcb|+|Pcbb| and 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 if the sum of the powers of both=|Pcb|-|Pcbb| and Pcbb>0 and Pcbb≧|Pcb|, the controller CCb controls the power conversion device BCSb to put it into 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 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 BCSa and the controller CCa are 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 included, which are installed 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 installed in the traction bus TSBb, a current transformer CTb1 and a current transformer CTb2 are installed 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 converters 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 satisfies a predetermined requirement.

2. 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 the traction feeder Fa1 and supplies power to the left adjacent power supply section traction network OCSa via the traction feeder Fa2, and the traction network OCS and the left adjacent power supply section traction network OCSa are connected via a sectionalizer.

3. 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 the traction feeder Fb1 and supplies power to the right adjacent power supply section traction network OCSb via the traction feeder Fb2, and the traction network OCS and the right adjacent power supply section traction network OCSb are connected via a sectionalizer.

4. The bilateral power supply ride-through power utilization system of the traction network according to claim 1, characterized in that 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 energy storage device ESDa and the DC side of the inverter device DACa via a common DC bus DCBa, the three-phase AC side of the inverter device DACa is connected to the power 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.

5. The bilateral power supply ride-through power utilization system of the traction network according to claim 1, characterized in that the power conversion device BCSb includes a rectifier ADCb and an inverter DACb, the DC side of the rectifier ADCb is connected to the DC side of the energy storage device ESDb and the inverter DACb via a common DC bus DCBb, the three-phase AC side of the inverter 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.

6. A control method based on a bilateral power supply 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; The control method based on the bilateral power supply ride-through power utilization system of the traction network according to any one of claims 1 to 5, further comprising the steps 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 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, characterized in that 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. The control method according to claim 7, characterized in that the step of the controllers CCa and CCb exchanging information according to the real-time power information acquired respectively includes a step of the controller CCa transmitting active power Pca and active power Pcaa data to the controller CCb for the OFL via an optical fiber, and the controller CCb transmitting active power Pcb and active power Pcbb data to the controller CCa for the OFL via an optical fiber.

9. The step 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, thereby allowing 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 to satisfy a predetermined requirement, 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 power Pca and the active power 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 operates the energy storage device ESDb in an energy storage state; and at the same time, if the sum of the two powers=Pca−Pcbb, the controller CCa controls the power converter BCSb to put it in standby; and at the same time, the controller CCa controls the power converter BCSa to put it in standby if the active power Pcbb≧Pca; 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 power Pca and the active power Pcb are ride-through powers flowing 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 operates the energy storage device ESDa in an energy storage state; and at the same time, if the sum of the two powers=Pcb−Pcaa, the controller CCb controls the power converter BCSb to be on standby; and at the same time, 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; 7. The control method according to claim 6, further 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 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.

10. The step 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, thereby allowing 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 to satisfy 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 the powers of both = |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 the powers of both = |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; 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; 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; if Pcbb>0 and Pcbb≧|Pcb|, the controller CCb controls the power converter BCSb to standby.

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