Adaptive method and system for power distribution network in urban rail transit power supply system

Abstract

The application provides a power distribution network adaptive method and system in urban rail transit power supply system. The method comprises the following steps: obtaining fault information caused by a first-level power distribution network, a second-level power distribution network and a third-level power distribution network and / or parameter values of related fault equipment; judging specific types of the faults caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network and / or whether the parameter values of the fault equipment exceed the range of normal parameters; and starting corresponding switching settings according to the specific types of the faults and the values of the parameter values of the fault equipment exceeding the range of normal parameters. The method and system make the three-level power distribution network quickly and accurately formulate related switching strategies, guarantee the normal power supply of the urban rail transit power supply system, and also take into account the mutual cooperation of multiple different power supply structures, thereby reducing the power-off time.

Description

Technical Field

[0001] This invention belongs to the field of urban rail transit power supply technology, specifically relating to an adaptive method and system for power distribution networks in urban rail transit power supply systems. Background Technology

[0002] Currently, urban rail power supply systems generally adopt a centralized power supply approach, constructing a three-tiered distribution network. To ensure normal power supply at all three levels, each level is equipped with a bus tie automatic transfer switch, which can quickly restore power supply when other power lines fail. The bus tie automatic transfer switch of the second-level distribution network is not affected by the first and third-level distribution networks. However, the bus tie automatic transfer switch of the first-level distribution network must also consider the requirements of the upper-level power grid. In practice, the incoming line typically recloses twice, with an interval of 2-4 seconds, and the automatic transfer function is generally activated 16 seconds after the incoming line reclosing time. The third-level distribution network is also a radial power supply network, and it is separated from the second-level distribution network, making it very difficult to select the "automatic transfer after power failure and automatic restoration after power restoration" time parameters. In actual engineering projects, the "automatic transfer after power failure" time is set to 5~9 seconds, and the "automatic restoration after power restoration" time is set to 2~5 seconds. These parameters cannot be matched with the first-level power distribution network. Therefore, it is impossible to accurately and quickly switch the power supply to the third-level power distribution network. This will cause the switching sequence of the third-level power distribution network to be disordered and chaotic, and the power load will be out of power for too long, affecting the normal operation of urban rail transit. Summary of the Invention

[0003] The purpose of this invention is to overcome the deficiencies in the prior art and provide an adaptive method and system for power distribution networks in urban rail transit power supply systems, which solves the problem of timely, fast and accurate switching of power supply to the third-level power distribution network when the first-level power distribution network fails.

[0004] To achieve the above objectives, this invention provides an adaptive distribution network method for urban rail transit power supply systems. This method is applied to a three-tiered distribution network in an urban rail transit power supply system, where the second-tier distribution network connects the information from the first-tier and third-tier distribution networks for adaptive power supply. The method includes the following steps: Obtain fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network, and the third-level power distribution network; Determine the specific type of the fault caused by the first-level power distribution network, the second-level power distribution network, and the third-level power distribution network, and / or the parameter values ​​of the faulty equipment exceeding the range of normal parameters; Based on the specific type of the fault and the value of the faulty equipment parameter that exceeds the normal parameter range, the corresponding switching settings are activated.

[0005] Furthermore, the specific types of faults caused by the first-level, second-level, and third-level power distribution networks include: main transformer out-of-operation faults and 110kV incoming line grounding reclosing faults; the specific types of faults in the second-level power distribution network include: line differential faults and line overcurrent faults; the specific types of faults in the third-level power distribution network include: 0.4kV bus faults and 0.4kV feeder circuit breaker overcurrent faults.

[0006] Furthermore, if the first-level distribution network fault is a main transformer out-of-operation fault or a 110kV incoming line grounding reclosing fault, then the adaptive power supply steps include: Obtain the rated current value of a single transformer in the substation of the first-level power distribution network; Determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network when the fault occurs. If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network, then the third-level load of the faulty substation of the first-level power distribution network shall be disconnected. If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads does not exceed the rated current value of a single transformer in the substation of the first-level distribution network, then the system topology of the third-level distribution network remains unchanged. Once the fault in the first-level power distribution network is cleared, the substations in the third-level power distribution network are sequentially restarted.

[0007] Furthermore, if the second-level power distribution network fault is a line differential fault or a line overcurrent fault, then the adaptive power supply step includes: Disconnect all tertiary loads sequentially from the faulty substation in the second-level distribution network to the substation at the end of the power supply arm of the second-level distribution network; The bus tie automatic transfer procedure of the substation where the second-level distribution network has failed is executed, and the third distribution network is supplied with power from one power source of the first-level distribution network; Initiate the automatic transfer switch procedure for the second-level power distribution network bus tie.

[0008] Furthermore, if the third-level power distribution network fault is a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault, then the adaptive power supply step includes: Obtain the rated current value of a single distribution transformer in the substation of the second-level power distribution network; Determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network when the fault occurs. If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level distribution network, then the third-level load of the faulty substation in the third-level distribution network will be disconnected; and the bus tie automatic transfer procedure of the third-level distribution network will be executed. Once the fault in the third-level power distribution network is cleared, the substations in the third-level power distribution network are restarted.

[0009] Preferably, the first, second, and third level power distribution networks all adopt a fast digital protection network that conforms to the IEC61850 standard.

[0010] This invention also provides an adaptive distribution network system for urban rail transit power supply systems, applied in a three-level distribution network of urban rail transit power supply systems. The second-level distribution network connects the information of the first-level distribution network and the third-level distribution network for adaptive power supply, and includes the following equipment units: The acquisition unit is used to acquire fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network; The judgment unit is used to determine the specific type of the fault caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network and / or the parameter value of the faulty equipment exceeds the range of normal parameters; The starting unit is used to start the corresponding switching settings according to the specific type of the fault and the value of the faulty equipment parameter that exceeds the range of normal parameters.

[0011] Furthermore, the fault information acquired by the acquisition unit includes: the specific fault types of the first-level power distribution network are main transformer out-of-operation fault and 110kV incoming line grounding reclosing fault; the specific fault types of the second-level power distribution network are line differential fault and line overcurrent fault; and the specific fault types of the third-level power distribution network are 0.4kV bus fault and 0.4kV feeder circuit breaker overcurrent fault.

[0012] Furthermore, if the fault information acquired by the acquisition unit is a main transformer out of operation fault or a 110kV incoming line grounding reclosing fault in the first-level power distribution network, then the following equipment units are included: The acquisition unit is used to acquire the rated current value of a single distribution transformer in the substation of the first-level power distribution network. The judgment unit is used to determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the first-level power distribution network when a fault occurs. Configuration unit, the configuration unit is used for: (1) If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the first-level power distribution network, then disconnect the third-level load of the faulty substation of the first-level power distribution network. (2) If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads does not exceed the rated current value of a single distribution transformer in the substation of the first-level distribution network, then the system topology of the third-level distribution network shall remain unchanged. The starting unit is used to start the substations in the third-level power distribution network to resume closing sequentially after the fault in the first-level power distribution network is cleared.

[0013] Furthermore, if the fault information acquired by the acquisition unit indicates that the fault in the second-level power distribution network is a line differential fault or a line overcurrent fault, then the following equipment units are included: Configuration unit, the configuration unit is used for: (1) Disconnect all tertiary loads sequentially from the faulty substation in the second distribution network to the substation at the end of the power supply arm of the second distribution network; (2) The bus tie automatic transfer procedure from the faulty substation of the second power distribution network to the third power distribution network is executed in sequence, and one power source of the first power distribution network supplies power to the third power distribution network; A starting unit is used to initiate the automatic transfer switch procedure of the second-level power distribution network bus tie.

[0014] Furthermore, if the fault information acquired by the acquisition unit is a third-level power distribution network fault, specifically a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault, then the following equipment units are included: The acquisition unit is used to acquire the rated current value of a single distribution transformer in the substation of the second-level power distribution network; The judgment unit is used to determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network when a fault occurs. Configuration unit, the configuration unit is used for: (1) If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level distribution network, then disconnect the third-level load of the faulty substation of the third-level distribution network; and (2) execute the automatic transfer procedure of the bus tie of the third-level distribution network. The starting unit is used to start the substation in the third-level power distribution network to resume closing after the fault in the third-level power distribution network is cleared.

[0015] This invention provides an adaptive method and system for power distribution networks in urban rail transit power supply systems. In the existing three-level power distribution network of urban rail transit power supply systems, information on various fault events occurring in the first-level power distribution network, as well as related equipment parameters, obtained through the second-level power distribution network, is directly sent to the third-level power distribution network via a fast, standardized digital network configured in the second-level network. This enables the third-level power distribution network to quickly and accurately formulate relevant switching strategies, ensuring the normal power supply of the urban rail transit power supply system. Furthermore, it takes into account multiple different power supply structures, not only the coordination of tripping strategies but also the coordination of protection strategies. If the fault is in the main substation, it can directly "cross" the medium-voltage network to issue commands to the third-level power distribution system, reducing power outage time. Attached Figure Description

[0016] Figure 1 This is a flowchart of the adaptive distribution network method in an urban rail transit power supply system provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of a three-level power distribution network for an urban rail power supply system provided in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the third-level power distribution network of the urban rail power supply system provided in Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of power distribution network fault types for an urban rail power supply system, provided in Embodiment 1 of the present invention. Figure 5 This is a flowchart of the adaptive distribution network method in an urban rail transit power supply system provided in Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of the power distribution network in the urban rail transit power supply system provided in Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of a main substation fault switching in an urban rail transit power supply system provided in Embodiment 2 of the present invention; Figure 8 This is a flowchart of the adaptive method for power distribution network in an urban rail transit power supply system provided in Embodiment 3 of the present invention; Figure 9This is a schematic diagram of a medium-voltage network fault switching in an urban rail transit power supply system provided in Embodiment 3 of the present invention; Figure 10 This is a flowchart of the adaptive method for power distribution network in an urban rail transit power supply system provided in Embodiment 4 of the present invention; Figure 11 This is a schematic diagram of a 0.4kV system fault switching in an urban rail transit power supply system provided in Embodiment 4 of the present invention; Figure 12 This is a schematic diagram of the unit structure of the adaptive power distribution network system in the urban rail transit power supply system provided in Embodiment 5 of the present invention. Detailed Implementation

[0017] The adaptive distribution network method and system of the urban rail transit power supply system of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] Example 1 Figure 1 This is a flowchart of an adaptive power distribution network method in an urban rail transit power supply system provided in Embodiment 1 of the present invention. Figure 1 As shown, this invention provides an adaptive power distribution network method for urban rail transit power supply systems, applied to a three-level power distribution network in urban rail transit power supply systems. The second-level power distribution network connects the information of the first-level and third-level power distribution networks for adaptive power supply, including the following steps: S101, Obtain fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network; S102, determine the specific type of the fault caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network and / or the parameter value of the faulty equipment exceeds the range of normal parameters; S103, based on the specific type of the fault and the value of the faulty equipment parameter exceeding the range of normal parameters, initiate the corresponding switching settings.

[0019] Specifically, in combination Figure 2 and Figure 3 This will illustrate the method of adaptive power distribution network in urban rail transit power supply systems.

[0020] Figure 2 This is a schematic diagram of a three-level power distribution network for an urban rail transit power supply system provided in Embodiment 1 of the present invention. Figure 1It is known that my country's urban rail transit power supply system is a three-tiered power distribution network: a radial distribution network at the first level, a chain distribution network at the second level, and a radial distribution network at the third level. In this three-tiered power distribution network, power is supplied through the radial connection of the first-level network, the chain connection of the second-level network, and the radial connection of the third-level network. The first level involves 110kV power from the urban power grid, supplied via a dedicated 110kV main substation for the urban rail transit project. The second level involves the 110kV main substation converting the supplied power into 35kV power, supplying power to traction substations or step-down substations along the urban rail route. The third level involves the traction substations or step-down substations along the route converting the 35kV power into traction power for locomotives and standard 0.4kV industrial power for stations or facilities along the route.

[0021] The first-level 110kV main substation of the urban rail transit power supply system adopts an internal bridge connection. Simultaneously, it receives power from two independent 110kV incoming lines from different upstream 220 / 110kV substations (i.e., 220kV to 110kV urban substations) to supply power to the 110 / 35kV main transformer of the main substation. To save investment, the incoming 110kV lines are generally overhead lines, making them susceptible to the effects of lightning strikes, storms, and other natural environmental factors. Therefore, the 110kV incoming line circuit breakers are equipped with reclosing and internal bridge automatic transfer functions. The logic is as follows: if the incoming line loses power, the reclosing function is activated. After three reclosing cycles, the reclosing function is blocked, and the incoming line circuit breaker is also blocked from closing. After a period of time, the internal bridge automatic transfer function is activated.

[0022] The second-level 35kV substation of the urban rail transit power supply system adopts a single busbar segmented connection, which ensures the independence of the two 35kV power sources and also guarantees that in the event of a power failure on one 35kV line, the 35kV bus tie circuit breaker within the substation can be closed as a backup circuit for supporting power supply within the substation. Power is drawn from the feeder side of the 110 / 35kV main transformer of the main substation. Both the incoming power circuit breaker and the outgoing power circuit breaker supplying power to adjacent 35kV substations are mounted on the same busbar segment. The incoming and outgoing circuit breakers of the 35kV substation are generally equipped with inter-substation differential protection and digital communication current protection. Since the 35kV medium-voltage ring network is generally a fully cable-powered network, it is less affected by natural factors; therefore, the 35kV incoming and outgoing circuit breakers are not equipped with reclosing functions. The automatic transfer function of the 35kV bus tie circuit breaker is integrated with the adjacent ring network fault detection. If there is no ring network fault, the automatic transfer function of the bus tie will not be activated, and the existing power supply network will be maintained.

[0023] Figure 3This is a schematic diagram of the third-level power distribution network of the urban rail transit power supply system provided in Embodiment 1 of the present invention. The 0.4kV power distribution system (0.4kV distribution cabinet) draws power from the feeder side of the 35 / 0.4kV distribution transformer in the 35kV substation through power cables or busbars (busbars). It adopts a single busbar segmented connection form. The 0.4kV power distribution system is the power supply end of the power and lighting system of the urban rail transit station. Figure 3 As shown, the entire power distribution center is concentrated in a 0.4kV distribution cabinet, forming a radial power supply with the station's power and lighting systems. The 0.4kV circuit breakers (801, 802, 803, 901, 902) are generally equipped with long-time delay, short-time delay, ground fault, and instantaneous protection. The 0.4kV power distribution system is equipped with two incoming circuit breakers (801 and 802) and one bus tie circuit breaker (803), allowing the 0.4kV distribution cabinet to quickly switch power sources in the event of a power outage on any of the three power sources. Simultaneously, the main load switches 901 and 902 are used to disconnect the three-level loads, ensuring the normal operation of the 0.4kV power distribution system.

[0024] In step S101, fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network and / or the third-level power distribution network are obtained. For some power distribution network faults, it is not necessary to monitor the parameter values ​​of related equipment, such as the maximum current value. Figure 4 A schematic diagram of power distribution network fault types for urban rail transit power supply systems, such as... Figure 4 As shown, the specific fault types are: main substation faults in the first-level distribution network of the urban rail transit power supply system, including main transformer out-of-operation faults and 110kV incoming line grounding reclosing faults; medium-voltage ring network system faults in the second-level distribution network, including line differential faults and line overcurrent faults; and 0.4kV system faults in the third-level distribution network, including 0.4kV bus faults or 0.4kV feeder circuit breaker overcurrent faults.

[0025] In step S102, it is determined that the specific type of the fault caused by the first-level distribution network, the second-level distribution network, and / or the faulty equipment parameter values ​​exceed the normal parameter range. Specifically, the 35kV substation sends the acquired fault type and related equipment parameters to the 0.4kV distribution system, i.e., the 0.4kV distribution cabinet, through the IEC61850 standard fast digital protection network. The IEC61850 standard fast digital protection network adopts a "publish / subscribe" communication mode, transmitting important event information between substations in parallel. The protection information of the 110kV circuit breaker and the 0.4kV circuit breaker also conforms to the IEC61850 standard and meets the general substation event transmission mechanism.

[0026] In step S103, the corresponding switching settings are activated based on the specific type of the fault and the value of the faulty equipment parameter that exceeds the range of normal parameters.

[0027] The beneficial effects of the adaptive distribution network method in the urban rail transit power supply system provided by this invention are as follows: Without changing the basic structure of the existing three-level distribution network of the urban rail transit power supply system, the method utilizes the feeder bus from the 110kV main substation through the 35kV substation and its medium-voltage protection network to reach the 0.4kV distribution cabinets of each station along the entire line. It connects the protection information of the 110kV main substation circuit breaker and the protection information of the 0.4kV circuit breakers of each station, and flexibly allocates the 0.4kV distribution cabinets for switching to support power supply. This not only achieves the "self-restoration" function required by the 0.4kV system, but also greatly reduces the power outage time.

[0028] Example 2 Figure 5 This is a flowchart of the adaptive distribution network method in an urban rail transit power supply system provided in Embodiment 2 of the present invention. Figure 5 As shown, if the first-level distribution network fault is a main transformer out-of-operation fault or a 110kV incoming line grounding reclosing fault, the distribution network adaptive method includes the following steps: S201, Obtain the rated current value of a single transformer in the substation of the first-level power distribution network; S202, determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network when the fault occurs. S203, if the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network, then disconnect the third-level load of the faulty substation of the first-level power distribution network. S204, if the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads does not exceed the rated current value of a single transformer in the substation of the first-level power distribution network, then the system topology of the third-level power distribution network remains unchanged. S205, after the fault in the first-level power distribution network is cleared, the substations in the third-level power distribution network are started to resume closing in sequence.

[0029] Specifically, Figure 6 The diagram shown is a power distribution network diagram of an urban rail transit power supply system provided in Embodiment 2 of the present invention. Now, according to... Figure 6 Explanation: This refers to the rated calculated current value of a single distribution transformer in the substation. This represents the sum of the effective values ​​of the 0.4kV system I and II bus currents and the calculated current values ​​of all fire-fighting loads in the 0.4kV system at the time of the fault at the nth substation. In special circumstances, while maintaining the existing 0.4kV power supply load, only fire-fighting loads are permitted for disaster relief and emergency response. When... At that time, disconnect all level-3 load switches in substation n, such as Figure 3 The 901 and 902 circuit breakers in the middle; conversely, At that time, the topology of the 0.4kV system of substation n remains unchanged. This represents a set of switching operation schemes sequentially from the 1st substation to the nth substation. When a main substation fault occurs, [the following is executed / implemented]. Compare and judge, and record the comparison results in the scheme set. Then, for each substation (from substation number 1 to n) on the main power supply arm, corresponding tertiary load disconnection or non-disconnection operations are performed. Next, the effective values ​​of the 0.4kV system current of all substations on the main power supply arm are accumulated. and Compare, The rated calculated current value of a single main transformer in the main substation. When When the main substation power supply arm is in operation, the 0.4kV switch status of all stations on the main substation power supply arm remains unchanged; otherwise, all tertiary loads on the main substation power supply arm are disconnected, and the result is included in the scheme set. .

[0030] Then, sequentially, 0.4kV bus tie support commands are issued from the power supply end, i.e., the main substation end, such as... Figure 3 If the 0.4kV fault-end incoming circuit breaker of the 803 circuit breaker trips, and if... Figure 3 If the main substation issues a fault signal, it corresponds to the disconnection of 801 in substation A, the activation of the automatic transfer switch for the 0.4kV bus tie, and the operation mode of the 0.4kV system in the substation is one power source supplying power to the 0.4kV system.

[0031] Figure 7 This is a schematic diagram of a main substation fault switching in an urban rail transit power supply system provided in Embodiment 2 of the present invention. First, according to... Figure 7 Instructions for switching: The first step, after the main substation fault is cleared and power is restored, is to determine the type of power supply restored to the main substation and perform the corresponding switching operation: If the type of power supply restored to the main substation is the successful activation of the 110kV internal bridge (1301) automatic transfer switch: according to the scheme set Maintain the three-level load status on the main power supply arm, and sequentially perform the 0.4kV bus tie tripping and 0.4kV incoming circuit breaker closing operations from the power supply end to restore the two power supply lines of the 0.4kV system from the 1st to the nth station; The second step, if the main substation's power supply restoration type is a successful reclosing of the 110kV incoming line (1101 / 1201), execute the power supply system restoration to normal status command. The specific switching operations are: sequentially opening the 0.4kV bus tie and closing the 0.4kV incoming line circuit breaker from the power supply end. After the previous stage is completed, update the scheme set. ,make ={Restore all three-level load switches on the main power supply arm to their pre-fault state}; The third step is to determine if the main substation fails to restore power, specifically if the 110kV incoming line (1101 / 1201) reclosing and the internal bridge (1301) automatic transfer switch both fail. This indicates a serious fault in the main substation's power supply system. The solution should be determined according to the proposed steps. Maintain the three-level load status on the main power supply arm and supply power according to the existing power supply topology.

[0032] After the switching operation is completed, the power supply system will maintain the above power supply system topology structure until the power supply system topology is manually changed. During the above process of a fault in the main substation, the power supply system topology of the medium-voltage 35kV ring network and the substation 35kV system will not change. The 0.4kV system operation commands will directly "cross" the medium-voltage 35kV system and effectively coordinate with the main substation 110kV system.

[0033] The beneficial effects of the adaptive distribution network method in the urban rail transit power supply system provided by this invention are as follows: Without changing the basic structure of the existing three-level distribution network of the urban rail transit power supply system, when the detected fault information is a main transformer out of operation fault or a 110kV incoming line grounding reclosing fault, the medium-voltage protection network of the 35kV substation connects to the protection information of the 110kV main transformer circuit breaker and the protection information of the 0.4kV circuit breakers of each station. The backup automatic transfer procedure is started using the bus tie of the 0.4kV distribution cabinet, and the 0.4kV distribution cabinet is flexibly dispatched to perform switching to support power supply. This not only achieves the "power restoration" function required by the 0.4kV system, but also greatly reduces the power outage time.

[0034] Example 3 Figure 8 This is a flowchart of the adaptive distribution network method in an urban rail transit power supply system provided in Embodiment 3 of the present invention. Figure 8 As shown, if the second-level distribution network fault is a line differential fault or a line overcurrent fault, the distribution network adaptive method includes the following steps: S301, sequentially disconnect all tertiary loads from the faulty substation in the second-level distribution network to the substation at the end of the power supply arm of the second-level distribution network; S302, execute the bus tie automatic transfer procedure of the substation where the second-level power distribution network has failed, and supply power to the third-level power distribution network under the fault state from one power source of the first-level power distribution network; S303, initiate the automatic transfer switch procedure for the second-level distribution network bus tie.

[0035] Specifically, the fault is determined to be a differential fault or an overcurrent fault in the medium-voltage system, manifested as follows: Figure 6 Circuit breakers such as 101, 201, and 401 send fault information. Since the medium-voltage system is a cascaded chain power supply system, the power supply system topology should not be easily changed. Therefore, when a fault occurs in the medium-voltage system, it is a serious fault. Figure 9 This is a schematic diagram of a medium-voltage network fault switching in an urban rail transit power supply system provided in Embodiment 3 of the present invention. According to... Figure 9 Instructions for switching: first, This is a set of switching operation schemes sequentially from substation m (the substation where the fault occurred) to substation n (the end of the main power supply arm). In the event of a medium-voltage ring network fault, all tertiary loads from substation m to substation n must be disconnected, and values ​​assigned... ={Closing Level 3 Load} and performing the operation.

[0036] Next, the 0.4kV bus tie (803) automatic transfer command is executed sequentially from substation m to substation n. One power supply from the substation supplies power to 0.4kV. The medium-voltage ring network system automatically executes the bus tie (301) automatic transfer procedure without manual intervention.

[0037] Specifically, if the medium-voltage bus tie automatic transfer fails, the 0.4kV system power supply topology of substations i to n remains unchanged. If the medium-voltage bus tie automatic transfer succeeds, the 0.4kV bus tie tripping and 0.4kV incoming circuit breaker closing operations are performed sequentially from the fault end. The three-level load switch maintains the original scheme set. constant.

[0038] The beneficial effects of the adaptive distribution network method in the urban rail transit power supply system provided by this invention are as follows: without changing the basic structure of the existing three-level distribution network of the urban rail transit power supply system, when the detected fault information is a differential fault or overcurrent fault of the line in the 35kV substation, the 35kV medium-voltage ring network system automatically executes the bus tie backup automatic transfer procedure without manual intervention. This not only achieves the "power restoration" function required by the 0.4kV system, but also greatly reduces the power outage time.

[0039] Example 4 like Figure 10 This is a flowchart of the adaptive distribution network method in an urban rail transit power supply system provided in Embodiment 4 of the present invention. Figure 10 As shown, if the third-level distribution network fault is a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault, the distribution network adaptive method includes the following steps: S401, Obtain the rated current value of a single distribution transformer in the substation of the second-level power distribution network; S402, determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network when the fault occurs. S403, if the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level distribution network, then disconnect the third-level load of the faulty substation of the third-level distribution network; and execute the bus tie automatic transfer procedure of the third-level distribution network. S404, after the fault in the third-level power distribution network is cleared, the substations in the third-level power distribution network are started to resume closing in sequence.

[0040] Specifically, the fault is determined to be a 0.4kV system fault, such as... Figure 6 As shown, the symptoms include the tripping of the 0.4kV incoming circuit breaker, the tripping of the incoming circuit breaker in the 0.4kV fault feeder circuit, and the tripping of the distribution transformer due to fault 401 or 402. Because the information is "published" by the 0.4kV system within the substation, no circuit breaker outside the substation has any "subscription" information about this 0.4kV system within the entire power supply system. Therefore, the information flow and operation of this fault are restricted to the 0.4kV system of the substation where the fault occurred. Figure 11 This is a schematic diagram of a 0.4kV system fault switching in an urban rail transit power supply system provided in Embodiment 4 of the present invention. Figure 11 Instructions for switching: first, This refers to the rated calculated current value of a single distribution transformer in the substation. This represents the sum of the effective values ​​of the currents on the I and II sections of the 0.4kV system at the time of the fault at the substation where the fault occurred, and the calculated current values ​​of all fire-fighting loads in the 0.4kV system. When... At that time, disconnect all three-level load switches (such as...) of the faulty substation. Figure 6 (Circuit breakers 901 and 902 in the middle), and vice versa. At that time, the capacity of a single distribution transformer in the substation can still guarantee power supply to the three-level load switch, and the instruction of segmented three-level load switch is not executed.

[0041] Next, install the 0.4kV bus tie (such as...). Figure 6 The 803) support command means that the 0.4kV fault-end incoming line circuit breakers (801 and 802) are tripped, the 0.4kV bus tie starts the automatic transfer procedure, and the substation operation mode is that a single transformer drives the entire 0.4kV load of the substation.

[0042] Next, if the incoming circuit breaker fault is cleared or the power supply voltage returns to normal, execute the command to restore normal operation status: that is, execute the operation steps of opening circuit 803, closing circuit 801, and closing circuits 901 and 902 in sequence.

[0043] The beneficial effects of the adaptive distribution network method in the urban rail transit power supply system provided by this invention are as follows: Without changing the basic structure of the existing three-level distribution network of the urban rail transit power supply system, when the detected fault information is a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault, the medium-voltage protection network of the 35kV substation connects to the protection information of the 110kV main substation circuit breaker and the protection information of the 0.4kV circuit breakers of each station. The backup automatic transfer procedure is started by using the bus tie of the 0.4kV distribution cabinet, and the 0.4kV distribution cabinet is flexibly dispatched to perform switching to support power supply. This not only achieves the "automatic power restoration" function required by the 0.4kV system, but also greatly reduces the power outage time.

[0044] Example 5 Figure 12 This is a schematic diagram of the unit structure of the adaptive power distribution network system in the urban rail transit power supply system provided in Embodiment 5 of the present invention. Figure 12 As shown in Embodiment 5 of the present invention, the adaptive distribution network system 500 in an urban rail transit power supply system is applied to a three-level distribution network in an urban rail transit power supply system. The second-level distribution network connects the information of the first-level and third-level distribution networks for adaptive power supply. The three-level distribution system is connected for power supply through a radial connection of the first-level distribution network, a chain connection of the second-level distribution network, and a radial connection of the third-level distribution network. It includes the following equipment units: Acquisition unit 501 is used to acquire fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network; Judgment unit 502 is used to determine the specific type of the fault caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network and / or the parameter value of the faulty equipment exceeds the range of normal parameters; The starting unit 503 is used to start the corresponding switching settings according to the specific type of the fault and the value of the faulty equipment parameter that exceeds the range of normal parameters.

[0045] Furthermore, the fault information acquired by the acquisition unit 501 includes: the specific fault types of the first-level power distribution network are main transformer out-of-operation fault and 110kV incoming line grounding reclosing fault; the specific fault types of the second-level power distribution network are line differential fault and line overcurrent fault; and the specific fault types of the third-level power distribution network are 0.4kV bus fault and 0.4kV feeder circuit breaker overcurrent fault.

[0046] Between the device unit judgment unit 502 and the start unit 503, there is also a configuration unit 504, which is used to configure the corresponding switching strategy when the judgment unit 502 analyzes the specific fault type.

[0047] In Embodiment 5 of the present invention, the equipment units of the distribution network adaptive system in the urban rail transit power supply system cooperate with each other to complete the distribution network adaptive method in the urban rail transit power supply systems of Embodiments 1, 2, 3 and 4. The specific operation process is the same as the steps in the above embodiments, and will not be repeated here.

[0048] The beneficial effects of the adaptive distribution network system in the urban rail transit power supply system provided by this invention are as follows: When the 35kV substation receives a fault information from the 110kV main substation indicating a circuit breaker tripping event, the feeder bus of the 110kV main substation reaches the 0.4kV distribution cabinets of each station along the entire line through the 35kV substation and its medium-voltage protection network. By using the disconnection of the 0.4kV circuit breaker at each station and the automatic transfer function of the bus tie, the 0.4kV distribution cabinets can be flexibly allocated to perform switching to support power supply. This not only achieves the "automatic power restoration" function required by the 0.4kV system, but also greatly reduces power outage time.

[0049] The adaptive distribution network system in the urban rail transit power supply system provided in this embodiment of the invention can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium (such as CD-ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code originally stored in a remote recording medium or a non-transitory machine-readable medium and subsequently stored in a local recording medium, downloaded via a network. Thus, the method described herein can be processed by software stored on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as ASIC or FPGA). It is understood that the computer, processor, microprocessor controller, or programmable hardware includes storage components (e.g., RAM, ROM, flash memory, etc.) capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the adaptive distribution network method in the urban rail transit power supply system described herein is implemented.

[0050] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power distribution network adaptive method in an urban rail transit power supply system, applied to a three-level power distribution network of an urban rail transit power supply system, the second-level power distribution network connects the information of the first-level power distribution network and the third-level power distribution network for adaptive power supply, characterized in that, The method includes the following steps: Obtain fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network, and the third-level power distribution network; Determine the specific type of the fault caused by the first-level power distribution network, the second-level power distribution network, and the third-level power distribution network, and / or the parameter values ​​of the faulty equipment exceeding the range of normal parameters; Based on the specific type of the fault and / or the value of the faulty equipment parameter exceeding the range of normal parameters, the corresponding switching settings are activated. If the first-level distribution network fault is a main transformer out-of-operation fault or a 110kV incoming line grounding reclosing fault, the adaptive power supply steps include: Obtain the rated current value of a single transformer in the substation of the first-level power distribution network; Determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network when the fault occurs. If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network, then the third-level load of the faulty substation of the first-level power distribution network shall be disconnected. If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads does not exceed the rated current value of a single transformer in the substation of the first-level distribution network, then the system topology of the third-level distribution network remains unchanged. After the fault in the first-level power distribution network is cleared, the substations in the third-level power distribution network are started to resume operation in sequence. If the secondary power distribution network fault is a line differential fault or a line overcurrent fault, the adaptive power supply steps include: Disconnect all tertiary loads sequentially from the faulty substation in the second-level distribution network to the substation at the end of the power supply arm of the second-level distribution network; The automatic transfer procedure of the bus tie of the substation where the second-level distribution network has failed is executed, and the third-level distribution network is supplied with power from one power source of the first-level distribution network under the fault condition. Initiate the automatic transfer switch procedure for the second-level distribution network bus tie; After the fault in the second-level power distribution network is cleared, the substations in the third-level power distribution network are started to resume operation in sequence; If the third-level power distribution network fault is a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault, the adaptive power supply steps include: Obtain the rated current value of a single distribution transformer in the substation of the second-level power distribution network; Determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network when the fault occurs. If the sum of the effective value of the bus current of the third-level distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level distribution network, then the third-level load of the faulty substation in the third-level distribution network is disconnected; and the bus tie automatic transfer procedure of the third-level distribution network is executed; when the fault in the third-level distribution network is cleared, the substations in the third-level distribution network are sequentially restored to closed position.

2. The adaptive distribution network method in the urban rail transit power supply system according to claim 1, characterized in that, The first, second, and third level power distribution networks adopt a fast digital protection network that conforms to the IEC 61850 standard.

3. An adaptive distribution network system for urban rail transit power supply systems, applied in a three-level distribution network of the urban rail transit power supply system, wherein the second-level distribution network connects the information of the first-level and third-level distribution networks for adaptive power supply, characterized in that... The system includes the following equipment units: The acquisition unit is used to acquire fault information and / or parameter values ​​of related faulty equipment caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network; The judgment unit is used to determine the specific type of fault caused by the first-level power distribution network, the second-level power distribution network and the third-level power distribution network and / or the faulty equipment parameter values ​​exceeding the normal parameter range; The starting unit is used to start the corresponding switching settings according to the specific type of the fault and the value of the faulty equipment parameter that exceeds the range of normal parameters. If the fault information acquired by the acquisition unit is a main transformer out of service fault in the first-level power distribution network or a 110kV incoming line grounding reclosing fault, the adaptive power supply process is as follows: The acquisition unit is used to acquire the rated current value of a single transformer in the substation of the first-level power distribution network; The judgment unit is used to determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the first-level power distribution network when a fault occurs. Configuration unit, used for: (1) If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single transformer in the substation of the first-level power distribution network, then disconnect the third-level load of the faulty substation of the first-level power distribution network. (2) If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads does not exceed the rated current value of a single transformer in the substation of the first-level power distribution network, then the system topology of the third-level power distribution network shall remain unchanged. The starting unit is used to start the substations in the third-level distribution network to resume closing sequentially after the fault in the first-level distribution network is cleared. If the fault information obtained by the acquisition unit indicates that the second-level power distribution network fault is a line differential fault or a line overcurrent fault, the adaptive power supply process is as follows: Configuration unit, used for: (1) Disconnect all tertiary loads sequentially from the substation where the fault occurred in the second-level distribution network to the substation at the end of the power supply arm of the second-level distribution network; (2) Execute the automatic transfer procedure of the bus tie of the substation where the second-level distribution network has failed, and supply power to the third-level distribution network under fault conditions from one power source of the first-level distribution network; The starting unit is used to initiate the automatic transfer switch procedure of the second-level distribution network bus tie. If the fault information obtained by the acquisition unit is a 0.4kV bus fault or a 0.4kV feeder circuit breaker overcurrent fault in the third-level power distribution network, the adaptive power supply process is as follows: The acquisition unit is used to acquire the rated current value of a single transformer in the substation of the second-level power distribution network; The judgment unit is used to determine whether the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network when a fault occurs. Configuration unit, used for: (1) If the sum of the effective value of the bus current of the third-level power distribution network and the calculated current value of all fire loads exceeds the rated current value of a single distribution transformer in the substation of the second-level power distribution network, then the third-level load of the faulty substation of the third-level power distribution network shall be disconnected. And (2) execute the bus tie automatic transfer procedure of the third-level distribution network; The starting unit is used to start the substation in the third-level power distribution network to resume closing after the fault in the third-level power distribution network is cleared.

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