Contact network electric split-phase protection device

Abstract

The utility model discloses an electric split-phase protection device for a contact network, and relates to the field of electrified railway traction power supply systems. The system is composed of a signal acquisition unit, an interphase fault identification unit, a fault removal unit, a power supply unit, a man-machine interface unit and an information interaction unit. An analog quantity acquisition circuit of the signal acquisition unit is connected with the interphase fault identification unit through a high-speed PCIE bus. The switching value acquisition circuit, the electric split-phase fault identification unit, the fault removal unit, the information interaction unit and the man-machine interface unit of the signal acquisition unit are connected together through the CAN bus, and the power supply unit supplies power to each unit through a device backboard power supply loop. The device is used for identifying and removing the phase-to-phase fault of the overhead line system, can improve the identification rate of the phase-to-phase fault, shortens the fault removal time, and achieves the quick removal of the fault, thereby avoiding the large-area power failure of a traction power supply system, and guaranteeing the normal operation of an electric locomotive.

Description

Technical Field

[0001] This utility model relates to the field of traction power supply systems for electrified railways, and in particular to a protective device for identifying and clearing phase-to-phase faults in the overhead contact system of electrified railways. Background Technology

[0002] The electric locomotive load on electrified railways is a single-phase load, while the power system is a three-phase power system. In order to reduce the negative sequence impact of the electric locomotive load on the power system, traction substations on electrified railways generally adopt a phase-switching connection power supply method to alternately connect to different phases of the power system.

[0003] The commutation connection power supply method results in different voltage phases on the left and right power supply arms of the substation. Therefore, a phase separator must be installed between the left and right power supply arms to isolate the different phase voltages. When the incoming power supplies of different traction substations come from different power systems or when the load on the power supply arms between two traction substations is unbalanced, a phase difference may also occur in the power supply arm between the two substations. Therefore, a phase separator must be installed between the power supply arms between the two substations to isolate the different phase voltages.

[0004] When an electric locomotive passes through a phase-splitter while energized, it can cause a phase-to-phase short circuit in the overhead contact line. If this fault cannot be identified quickly, it can lead to cascading tripping, causing a large-scale power outage in the traction power supply system, preventing the electric locomotive from operating normally, severely impacting transportation, and in severe cases, potentially burning out the entire short-circuited section of the overhead contact line.

[0005] Currently, the solution for identifying and clearing phase-to-phase faults in the overhead contact system involves configuring multiple feeder protection devices in substations and sectioning stations, using current increment protection, impedance protection, and phase-to-phase undervoltage overcurrent protection components to identify phase-to-phase faults. However, due to the characteristics of phase-to-phase faults in the overhead contact system—high transition resistance and uncertain fault angle—existing feeder protection devices face difficulties in fault identification. Clearing phase-to-phase faults requires the cooperation of multiple feeder protection devices. Since there is no information exchange between these devices, fault clearing is achieved through protection time-delay coordination, resulting in long fault clearing times (>400ms), which can lead to cascading tripping. Utility Model Content

[0006] The purpose of this invention is to design a protective device for identifying and clearing phase-to-phase faults in overhead contact lines, which can improve the identification rate of phase-to-phase faults and shorten the fault clearing time after a phase-to-phase fault occurs.

[0007] The technical solution proposed in this utility model is implemented as follows: A contact network phase separation protection device, characterized in that it consists of a signal acquisition unit, a phase-to-phase fault identification unit, a fault clearing unit, a power supply unit, a human-machine interface unit, and an information interaction unit. The signal acquisition unit includes an analog quantity acquisition circuit and a digital quantity acquisition circuit. The analog quantity acquisition circuit is connected to the phase-to-phase fault identification unit through a high-speed PCIe bus. The digital quantity acquisition circuit is connected to the phase separation fault identification unit, the fault clearing unit, the information interaction unit, and the human-machine interface unit through a high-speed PCIe bus. The power supply unit supplies power to each unit through the power supply circuit on the back panel of the device. The analog signal acquisition circuit of the signal acquisition unit includes an analog converter T1, an analog-to-digital converter chip AD, and protection and filtering circuits connected between them. The analog signal input terminal of the analog-to-digital converter chip AD is connected to the output terminal of the filtering circuit, and the digital signal output terminal is connected to the input terminal of the phase-to-phase fault identification unit via a high-speed PCIe bus. The digital signal acquisition circuit of the signal acquisition unit includes multiple optocouplers OP, an EEPROM memory chip, an input processing main control chip MCU, and a CAN transceiver. Multiple signal input ports of the input processing main control chip MCU are connected to the signal output ports of multiple optocouplers, and the signal output port of the input processing main control chip MCU is connected to the CAN transceiver. The I / O interface of the input processing main control chip MCU is connected to the EEPROM memory chip, which stores action thresholds and release thresholds. The phase-to-phase fault identification unit includes a CPU chip, an FPGA chip, a memory chip, a storage chip, and a 100Mbps PHY transceiver. The CPU chip is connected to the memory chip via an SDC interface, to the storage chip via an SPIO controller, and to the 100Mbps PHY transceiver via an EMAC controller. The CPU chip is also connected to the FPGA chip via a GMAC controller. The FPGA chip is connected to the CAN bus via a CAN transceiver. The FPGA chip also includes a PCIE controller for receiving analog information from the analog acquisition loop and an RS485 chip for receiving B-code time synchronization signals. The information interaction unit includes an FPGA chip, a 100Mbps optical module, and a 100Mbps PHY transceiver Ethernet interface. The FPGA chip includes a GOOSE protocol controller, an EMAC controller 3, an EMAC controller 4, a 100Mbps optical module A, and a 100Mbps optical module B, used to realize fast information interaction between electrical phase-separation protection devices. The FPGA chip is connected to the CAN bus via a CAN transceiver and is connected to the 100Mbps optical modules A and B via EMAC controllers 3 and 4, which are capable of GOOSE protocol communication. The 100Mbps optical modules A and B include optical Ethernet interfaces 1 and 2, which use the GOOSE protocol to control and realize protection communication. The FPGA chip is also connected to the 100Mbps PHY transceivers A and B via EMAC controllers 1 and 2, which are capable of MMS protocol communication. The PHY transceivers A and B include electrical Ethernet interfaces 1 and 2, which use the MMS protocol to control and realize monitoring communication.

[0008] The contact wire phase-splitting protection device provided by this utility model addresses the problems of difficult phase-to-phase fault identification and slow fault clearing in the contact wire. By collecting the switching and electrical quantities of the stations on both sides of the contact wire phase split, analyzing the voltage vector change characteristics and switching quantity combination mode during phase-to-phase faults, it accurately identifies phase-to-phase faults. Then, through the phase-to-phase information transmission channel, it uses the GOOSE fast information transmission protocol to send the fault trip signal to all phase-to-phase protection devices in the phase-to-phase protection system, thereby achieving rapid fault clearing. Attached Figure Description

[0009] Figure 1 Schematic diagram of hardware composition and connection of contact network phase separation protection device

[0010] Figure 2 : Analog signal acquisition unit

[0011] Figure 3 Signal acquisition unit switch quantity acquisition circuit

[0012] Figure 4 Phase-to-phase fault identification unit

[0013] Figure 5 Overhead Contact Line Phase-to-Phase Fault Identification Logic

[0014] Figure 6 Information Interaction Unit

[0015] Figure 7 Schematic diagram of the overhead contact line phase separation protection device network Detailed Implementation

[0016] The technical solution and advantages of this utility model will be further described below with reference to the accompanying drawings and embodiments. For example... Figure 1 As shown, the signal acquisition unit mainly completes the acquisition of analog and digital quantities related to the phase separation of the contact network. The phase-to-phase fault identification unit completes the phase-to-phase fault identification of the contact network based on the analog and digital information from the acquisition unit, and sends the fault clearing signal to the fault clearing unit. The fault clearing unit completes the tripping of the circuit breaker at the installation location of the phase separation protection device of the contact network. The information interaction unit transmits the phase separation fault information and fault clearing information of the contact network to other phase separation protection devices of the contact network. After receiving the phase-to-phase fault and fault clearing information, the other phase separation protection devices of the contact network complete the tripping of the circuit breaker near the other phase separation protection devices, thereby realizing the phase separation fault clearing.

[0017] The analog signal acquisition circuit of the signal acquisition unit consists of an analog-to-digital converter T1, a TVS diode, an inductor L1, resistors R1 to R6, capacitors C1 to C2, and an AD converter chip. Figure 2As shown, the input analog signal is converted into a low-voltage signal by a converter, L1 filters out high-frequency AC analog signals, a TVS transient suppression diode prevents externally input transient high voltage from damaging subsequent circuit components, R1 and R2 perform voltage division, and R3-R6 and C1-C2 together form a low-pass filter circuit. The processed analog signal is input to the AD chip for analog-to-digital conversion and then input to the phase-to-phase fault identification unit via a high-speed PCIe bus.

[0018] The signal acquisition unit's digital input acquisition circuit consists of optocouplers OP1-21, an EEPROM memory chip, an input processing main control chip MCU, and a CAN transceiver. Figure 3 As shown, switch quantities 1-21 are connected to the input processing main control chip MCU via high-linearity optocouplers OP1-OP21. The main control chip confirms the validity of the switch quantity based on the input voltage value of the optocoupler and transmits the data via the CAN bus on the device backplane through a CAN transceiver. The innovation of the switch quantity acquisition circuit is the use of high-linearity optocouplers. Based on the characteristic of high-linearity optocouplers converting different input voltage levels into analog signals of different magnitudes, adaptive input detection at 110V / 220VDC voltage levels is achieved. The specific implementation scheme is as follows: the main control chip reads the input voltage level of 220V / 110V, as well as the action threshold and release threshold configured in the storage chip. Typically, the action threshold is set to 60% of the rated input voltage, and the release threshold is set to 40% of the rated input voltage. The main control chip periodically collects the input status and compares the collected input voltage value with the action threshold and release threshold. When the input voltage value is greater than the action threshold, the input is determined to be valid. When the input voltage value is less than the release threshold, the input is determined to be invalid. When the input voltage value is greater than the release threshold but less than the action threshold, the current state is maintained.

[0019] The phase-to-phase fault identification unit consists of a CPU chip, an FPGA chip, a memory chip, a storage chip, and a 100Mbps PHY transceiver, such as... Figure 4 As shown. The CPU chip connects to the memory chip via the SDC interface, to the storage chip via the SPIO controller, and to the 100Mbps PHY transceiver via the EMAC controller. The CPU chip also connects to the FPGA chip via the GMAC controller. The FPGA chip connects to the CAN bus via the CAN transceiver, receives analog information from the analog acquisition circuit via the PCIE controller, and receives B-code time synchronization signals via the RS485 chip. The phase-to-phase fault identification unit receives analog information from the data sampling unit and the fault identification program built into the storage chip. Using the fault identification processing unit of the CPU chip, it completes phase-to-phase fault identification and sends a fault clearing command to the fault clearing unit via the CAN bus. The specific phase-to-phase fault identification logic is as follows: Figure 5As shown, the logic for identifying interphase faults by using the characteristics of voltage and angle on both sides of the phase is not affected by the fault transition resistance, and the fault identification is reliable and accurate.

[0020] The information interaction unit consists of an FPGA chip, a 100Mbps optical module, a 100Mbps PHY transceiver Ethernet interface, and so on. Figure 6 As shown, the FPGA chip is connected to the CAN bus via a CAN transceiver, and to 100Mbps optical modules A and B via EMAC controllers 3 and 4. The GOOSE protocol is used to control and implement the GOOSE protocol communication function of the protection communication interface optical Ethernet ports 1 and 2. EMAC controllers 1 and 2 are connected to 100Mbps PHY transceivers A and B, and the MMS protocol is used to control and implement the MMS protocol communication function of the monitoring communication interface electrical Ethernet ports 1 and 2.

[0021] The innovation of the information interaction unit is that it realizes rapid information interaction between electrical phase-separation protection devices through the GOOSE protocol controller, EMAC controller 3, EMAC controller 4, 100M optical module A, and 100M optical module B. When an electrical phase-separation protection device of the contact network identifies an electrical phase-separation fault, it sends a linkage trip signal to the adjacent electrical phase-separation protection device through the GOOSE protocol while tripping the circuit breaker through its own fault clearing unit. After receiving the linkage trip command, the adjacent electrical phase-separation protection device trips the circuit breaker through its own fault clearing unit. Compared with the original fault clearing method of time-limited coordination, the fault clearing time can be shortened from the original 400ms to 100ms.

[0022] Communication and networking methods for contact network phase separation protection devices, such as Figure 7 As shown, the protection communication interface optical Ethernet ports 1 and 2 of the phase-separation protection device are connected to information transmission channels A and B respectively, realizing information interaction between phase-separation protection devices 1 to 4 based on the GOOSE protocol. The monitoring communication interface electrical Ethernet port of the phase-separation protection device is connected to the station control layer network, realizing information interaction between the phase-separation protection device and the monitoring host based on the MMS protocol.

[0023] The implementation schemes for the human-machine interface unit and the fault isolation unit are similar to those in the prior art and will not be described further.

[0024] The beneficial effects of this utility model are as follows:

[0025] This utility model's switch quantity acquisition circuit uses a high linearity optocoupler. Based on the characteristics of the high linearity optocoupler in converting different input voltage levels into analog signals of different magnitudes, it achieves adaptive input detection at 110V / 220VDC voltage levels.

[0026] The fault identification unit of this utility model adopts a scheme that combines the phase-to-phase voltage fault vector characteristics at both ends of the contact network with switch quantity information to identify phase-to-phase faults. This scheme is not affected by the fault transition resistance and the fault identification is reliable and accurate.

[0027] This invention combines multiple contact network phase-to-phase protection and control devices and information transmission channels to form a contact network phase-to-phase fault protection system. The device uses the GOOSE protocol to transmit information, reducing the fault clearing time from the original 400ms to 100ms.

Claims

1. A catenary electric neutral section protection device, characterized in that: The device is composed of a signal acquisition unit, an inter-phase fault identification unit, a fault removal unit, a power supply unit, a man-machine interface unit, and an information interaction unit.

2. The catenary electric neutral section protection device according to claim 1, characterized in that: The analog quantity acquisition circuit of the signal acquisition unit comprises an analog quantity transformer T1, an analog-digital conversion chip AD, and a protection circuit and a filter circuit connected between the two, the analog signal input end of the analog-digital conversion chip AD is connected with the output end of the filter circuit, and the digital signal output end is connected to the input end of the inter-phase fault identification unit through a high-speed PCIE bus; the switching quantity acquisition circuit of the signal acquisition unit comprises a plurality of optical couplings OP, a storage chip EEPROM, an incoming processing main control chip MCU, and a CAN transceiver, the signal input ports of the incoming processing main control chip MCU are connected with the signal output ports of the plurality of optical couplings respectively, the signal output port of the incoming processing main control chip MCU is connected with the CAN transceiver, and the I / O interface of the incoming processing main control chip MCU is connected with the storage chip EEPROM in which the action threshold and the release threshold are stored.

3. The catenary electric neutral section protection device according to claim 1, characterized in that: The inter-phase fault identification unit comprises a CPU chip, a FPGA chip, a memory chip, a storage chip, and a hundred-megabit PHY transceiver, the CPU chip is connected with the memory chip through an SDC interface, connected with the storage chip through an SPIO controller, and connected with the hundred-megabit PHY transceiver through an EMAC controller, the CPU chip is connected with the FPGA chip through a GMAC controller, the FPGA chip is connected with a CAN bus through a CAN transceiver, and the FPGA chip further comprises a PCIE controller for receiving analog quantity information input by the analog quantity acquisition circuit and an RS485 chip for receiving a B code time signal.

4. The catenary electric neutral section protection device according to claim 1, characterized in that: The information interaction unit comprises a FPGA chip, a hundred-megabit optical module, and a hundred-megabit PHY transceiver Ethernet interface, the FPGA chip comprises a GOOSE protocol controller for realizing fast information interaction between electric split-phase protection devices, EMAC controllers 3 and 4, and the hundred-megabit optical modules A and B, the FPGA chip is connected with the CAN bus through a CAN transceiver, connected with the hundred-megabit optical modules A and B through the EMAC controllers 3 and 4 capable of realizing GOOSE protocol communication function, the hundred-megabit optical modules A and B comprise optical Ethernet interfaces 1 and 2 controlled by the GOOSE protocol for realizing protection communication, the FPGA chip is further connected with the hundred-megabit PHY transceivers A and B through the EMAC controllers 1 and 2 capable of realizing MMS protocol communication function, and the PHY transceivers A and B comprise electrical Ethernet interfaces 1 and 2 controlled by the MMS protocol for realizing monitoring communication.

Images