Feed protection device and method

Abstract

The invention provides a feed protection device and method, and relates to the technical field of feed protection, the device comprises a data acquisition module, a controller and a switch control module, the controller is used for controlling the switch control module under the condition that each feed-out loop is in an overcurrent protection state; based on a digital signal corresponding to a phase voltage value of each phase of alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feed-out loop, which are acquired by a data acquisition module, whether overcurrent occurs in each feed-out loop is judged, and when it is determined that the overcurrent occurs in any feed-out loop, the current value of each phase of alternating current in each feed-out loop is detected. And the switch control module is controlled to cut off the connection between the UPS system and any feed-out loop. According to the feed protection device and method provided by the invention, the fault feed-out loop with the fault in the urban rail transit system can be removed more timely and more effectively by combining the current criterion and the voltage criterion, and the operation stability of the UPS system and the urban rail transit system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of feeder protection, and in particular to a feeder protection device and method. Background Art

[0002] With the development of economy and the continuous improvement of people's living standards, the urban rail transit system has brought many positive impacts and conveniences to people's lives with its punctuality, speed, safety and stability.

[0003] Normally, urban rail transit systems are powered by uninterruptible power supply (UPS) systems. The feeder protection device in the UPS system is designed to ensure that the UPS system can operate safely and reliably under various abnormal conditions, thereby protecting the power supply of the urban rail transit system from damage.

[0004] However, in the related art, when a circuit in the urban rail transit system fails, the traditional feeder protection device in the UPS system is difficult to promptly and effectively cut off the faulty circuit, causing the above-mentioned faulty circuit to affect other non-faulty circuits in the urban rail transit system, causing the scope of adverse effects of the faulty circuit to expand. Therefore, how to more promptly and effectively cut off the faulty circuit in the urban rail transit system is a technical problem that needs to be solved in this field. Summary of the invention

[0005] The present invention provides a feeding protection device and method, which are used to solve the defect that it is difficult to timely and effectively cut off the fault circuit in the urban rail transit system in the prior art, and to achieve more timely and effective cutting off of the fault circuit in the urban rail transit system.

[0006] The present invention provides a feeding protection device, comprising: a data acquisition module, a controller and a switch control module; the data acquisition module, the controller and the switch control module are electrically connected in sequence; The data acquisition module is used to obtain a digital signal corresponding to a phase voltage value of each phase of alternating current output by an uninterruptible power supply UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feeder circuit, and then send the digital signal corresponding to a phase voltage value of each phase of alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feeder circuit to the controller, and the UPS system supplies power to each load device in the urban rail transit system through each feeder circuit; The controller is used to determine whether an overcurrent occurs in each of the feeder circuits based on a digital signal corresponding to a phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of the alternating current in each feeder circuit when each of the feeder circuits is in an overcurrent protection state, and to control the switch control module to cut off the connection between the UPS system and any of the feeder circuits when it is determined that an overcurrent occurs in any of the feeder circuits; The switch control module is used to cut off the connection between the UPS system and any one of the feeder circuits in response to the control of the controller.

[0007] According to a feeder protection device provided by the present invention, the controller is specifically used to determine that the voltage transformer is not broken at the current moment based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system; if it is determined that the current value of any phase of the alternating current in any feeder circuit at any historical moment exceeds a predefined first current threshold and the line voltage value of any phase of the alternating current output by the UPS system at the current moment is lower than a predefined first voltage threshold based on the digital signal corresponding to the current value of any phase of the alternating current in any feeder circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the alternating current output by the UPS system, then it is determined that overcurrent occurs in any feeder circuit, and the duration of the interval between any historical moment and the current moment does not exceed the preset duration.

[0008] According to a feeder protection device provided by the present invention, the controller is also used to control the switch control module to respectively cut off the connection between the UPS system and each of the feeder circuits after delaying a first delayed power-off time corresponding to each of the feeder circuits, when it is determined that the UPS system is operating in a battery inverter mode based on status information of the UPS system, and the first delayed power-off time corresponding to each of the feeder circuits is predefined.

[0009] A feed protection device according to the present invention further includes: a communication module; the communication module includes a plurality of RS485 serial ports, a plurality of RJ45 Ethernet interfaces and a communication protocol conversion module, each of the RS485 serial ports is connected to each of the RJ45 Ethernet interfaces via the communication protocol conversion module; The RS485 serial port is used to connect the sub-devices in the UPS system; The RJ45 is used to connect to a monitoring system, and the monitoring system is used to monitor the operating status of the UPS system; The communication protocol conversion module is used to convert the communication protocol of the input data.

[0010] According to a feeder protection device provided by the present invention, the controller is used to control the switch control module to cut off the connection between the UPS system and any feeder circuit after delaying the second delayed power-off time corresponding to any feeder circuit when it is determined that an overcurrent occurs in any feeder circuit, and the second delayed power-off time corresponding to each feeder circuit is predefined.

[0011] According to a feeder protection device provided by the present invention, the data acquisition module includes a voltage transformer and an analog-to-digital converter; the voltage transformer is connected to the UPS system and the analog-to-digital converter respectively, and the analog-to-digital converter is connected to the controller; The voltage transformer is used to obtain a test voltage value of each phase of the AC power output by the UPS system based on a phase voltage value of each phase of the AC power output by the UPS system, and then send the test voltage value of each phase of the AC power output by the UPS system to the analog-to-digital converter; The analog-to-digital converter is used to generate a phase voltage value of each phase of the AC power output by the UPS system based on a test voltage value of each phase of the AC power output by the UPS system, and then send the phase voltage value of each phase of the AC power output by the UPS system to the controller.

[0012] According to a feeding protection device provided by the present invention, the controller is specifically used to determine, based on a digital signal corresponding to a phase voltage value of each phase of AC power output by the UPS system, that the voltage transformer is not broken at the current moment; if, based on a digital signal corresponding to a current value of any phase of AC power in any feeding circuit at any historical moment and a digital signal corresponding to a phase voltage value of any phase of AC power output by the UPS system at the current moment, it is determined that the current value of any phase of AC power in any feeding circuit at any historical moment exceeds a predefined second current threshold and the phase voltage value of any phase of AC power output by the UPS system at the current moment is lower than a predefined second voltage threshold, then it is determined that an overcurrent occurs in any feeding circuit, and the duration between any historical moment and the current moment does not exceed a preset duration.

[0013] According to a feeder protection device provided by the present invention, the controller is further used to, when each of the feeder circuits is in an overload protection state, determine whether each of the feeder circuits is overloaded based on a digital signal corresponding to a current value of each phase of the alternating current in each of the feeder circuits, and, when it is determined that any of the feeder circuits is overloaded, control the switch control module to cut off the connection between the UPS system and any of the feeder circuits; The controller is also used to control the switch control module to cut off the connection between the UPS system and any feeder circuit after delaying a third delayed power-off time corresponding to any feeder circuit when it is determined that any feeder circuit is overloaded, and the third delayed power-off time corresponding to each feeder circuit is predefined.

[0014] A feeding protection device according to the present invention further includes: a display device; the display device is electrically connected to the controller; The controller is further configured to, when determining that an overcurrent occurs at the current moment in any feeder circuit, control the display device to display an alarm message for prompting that an overcurrent occurs at the current moment in any feeder circuit, and the controller is further configured to control the display device to display target information, wherein the target information includes at least one of the voltage value of each phase, the current value of each phase, the first current threshold, and the first delayed power-off time length corresponding to each feeder circuit; The display device is used to display alarm information for prompting that overcurrent occurs in any of the feed-out circuits at the current moment in response to the control of the controller, and the display device is also used to display the target information in response to the control of the controller.

[0015] The present invention also provides a feeding protection method implemented based on any of the feeding protection devices as described above, comprising: Obtaining a digital signal corresponding to a phase voltage value of each phase of alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feed-out circuit; When each of the feeder circuits is in an overcurrent protection state, judging whether an overcurrent occurs in each of the feeder circuits based on a digital signal corresponding to a phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of the alternating current in each of the feeder circuits; When it is determined that an overcurrent occurs in any feeder circuit, the connection between the UPS system and any feeder circuit is cut off.

[0016] The present invention also provides an electronic device, comprising a memory, a controller, and a computer program stored in the memory and executable on the controller, wherein the controller implements any of the above-mentioned feeding protection methods when executing the computer program.

[0017] The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a controller, the feeding protection method as described above is implemented.

[0018] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a controller, the feeder protection method described above is implemented.

[0019] The feeder protection device and method provided by the present invention can judge whether each feeder circuit has overcurrent based on the phase voltage value of each phase of AC power output by the UPS system and the current value of each phase of AC power in each feeder circuit for supplying power to load equipment in the urban rail transit system by the UPS system, and cut off the connection between the UPS system and the above feeder circuit when it is determined that any feeder circuit has overcurrent. By combining current judgment and voltage judgment, the defect that the thermal magnetic release type molded case circuit breaker and / or air switch arranged in the above faulty feeder circuit cannot be successfully triggered to trip due to the output current limitation of the UPS system in the case of a feeder circuit failure, thereby failing to timely and effectively cut off the faulty feeder circuit in the urban rail transit system, can be overcome, the faulty feeder circuit in the urban rail transit system can be cut off more timely and effectively, the influence of the faulty feeder circuit on other non-faulty feeder circuits can be reduced, the influence range of the faulty feeder circuit can be better controlled, and the operation stability of the UPS system and the urban rail transit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 This is one of the structural schematic diagrams of the feeding protection device provided by the present invention.

[0022] Figure 2 It is a logical schematic diagram of overcurrent protection performed by the feeder protection device provided by the present invention.

[0023] Figure 3 This is the second structural schematic diagram of the feeding protection device provided by the present invention.

[0024] Figure 4 It is a flow chart of the feeding protection method provided by the present invention.

[0025] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the description of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, in the description of the present application, "and / or" represents at least one of the connected objects, and the character " / " generally represents that the front and back associated objects are in an "or" relationship.

[0029] It should be noted that the core systems in the urban rail transit system, such as the rail transit communication system, signal system, integrated monitoring system, urban rail transit automatic ticket collection system (Automatic Fare Collection, AFC) and passenger information system (Passenger Information System, PIS), are the key loads among the primary loads. The stable and reliable operation of the above core systems is of great significance to ensuring the passenger service quality of the urban rail transit system.

[0030] With the continuous updating of urban rail transit equipment technology, more and more communication, signal and integrated monitoring systems are integrated in urban rail transit systems, and the UPS system centrally supplies power to rail transit communication systems, signal systems, integrated monitoring systems, AFC and PIS and other core systems. With the widespread application of UPS in the field of urban rail transit technology, the safe and stable operation of the UPS system has also become very important.

[0031] Among them, the UPS system is a system that can provide continuous and stable power supply, usually composed of rectifiers, inverters and batteries. When the mains power is normal, the UPS system can stabilize the mains power and supply it to the load, while charging the battery; when the mains power is interrupted or the voltage fluctuates greatly, the UPS system converts the DC power of the battery into AC power and continues to supply power to the load, thus ensuring the continuous operation of the load.

[0032] UPS system usually includes UPS host, feeder cabinet, bypass cabinet, feeder cabinet and other parts. UPS host is the core part of UPS system, which is responsible for converting the input AC power into DC power and storing it in the built-in battery. When the city power is interrupted or the voltage fluctuates, the UPS host will invert the DC power into stable AC power and continue to supply power to the load. The feeder cabinet is responsible for distributing the output power of the UPS host to each load device. The feeder cabinet usually includes an input end (connected to the output end of the UPS host), an output end (distributing power to each load through the feeder), a distribution switch (used to control the power on and off of each load), monitoring instruments (such as voltmeters, ammeters, etc., used to monitor the voltage, current and other parameters of the feeder cabinet in real time) and feeding protection devices.

[0033] To ensure the safe and reliable operation of the UPS system, the feeder protection devices configured in the UPS system must be complete and reliable.

[0034] In the related art, the traditional feeder protection device configured in the feeder cabinet of the UPS system usually only includes a thermal-magnetic tripping molded case circuit breaker and / or an air switch for each feedback line, and is configured with a C-type tripping curve, thereby relying on the above-mentioned thermal-magnetic tripping molded case circuit breaker and / or air switch to perform thermal and magnetic protection on each feedback line.

[0035] UPS systems have a variety of protection functions, one of which is short-circuit protection. In the actual operation of urban rail transit systems, if the UPS system detects a short-circuit fault on the feeder side (i.e., the cable from the UPS system to the urban rail transit system), the UPS host will respond quickly to prevent the fault from expanding by quickly shutting down the insulated-gate bipolar transistor (IGBT) or limiting the output current.

[0036] However, due to the rapid shutdown of IGBT or the limitation of output current, the thermal magnetic release molded case circuit breaker and / or air switch in the above-mentioned traditional feeder protection device may not receive enough fault current in time, and thus fail to trip in time and effectively to cut off the fault circuit. Since the thermal magnetic release molded case circuit breaker and / or air switch fail to trip in time, the fault circuit continues to exist and affects other non-fault circuits, which may cause damage to the equipment of other non-fault circuits or affect their normal operation.

[0037] Among them, the thermal-magnetic release molded case circuit breaker needs the fault current to exceed the set value by several times or even more than ten times and last for more than half to one cycle before it can quickly trip to cut off the fault circuit. When the inverter control program of the UPS host detects a large fault current, the above control program will quickly limit the output current of the UPS system to 120% or 150% of the rated current for several seconds to protect the inverter. This results in the fault current failing to reach the tripping current value set by the thermal-magnetic release molded case circuit breaker and / or the air switch, and thus the fault circuit cannot be cut off, causing the feed voltage to be lowered, which in turn affects the remaining non-fault circuits, resulting in an expansion of the fault impact range.

[0038] The power failure of core systems such as rail transit communication system, signal system, integrated monitoring system, AFC and PIS will have a certain impact on the normal operation of urban rail transit system. Therefore, how to more timely and effectively cut off the faulty circuit in the urban rail transit system is a technical problem to be solved in this field.

[0039] Moreover, in the case of a double loss of AC power supply to core systems such as rail transit communication systems, signal systems, integrated monitoring systems, AFC and PIS, different types of core systems have different operating requirements after the AC power outage. For example, the signal system may require a longer backup power supply to ensure the safe operation of the train, while the PIS may be shut down after completing the necessary broadcasting in a short time. However, the traditional UPS system in the related art is difficult to power off different types of load equipment in different time periods when the load equipment in the urban rail transit system loses both AC power supply.

[0040] In addition, the UPS host, voltage stabilizing cabinet, PLC, watt-hour meter, battery inspection meter and other equipment in the UPS system in the related technology need to communicate with the monitoring system so that the monitoring system can obtain the operating status and data of each device in the UPS system in real time. The communication between the UPS system and the monitoring system is usually implemented by a gateway interface device. The above-mentioned gateway interface device first connects to each serial communication device in the UPS system in a hand-in-hand manner through the Modbus-Rtu protocol and the RS485 interface. After access, the above-mentioned gateway device converts the data of these devices into the Modbus-Tcp protocol so as to upload the operating information of each device in the UPS system to the monitoring system.

[0041] However, affected by the performance of the above-mentioned gateway device, this communication method has certain defects in actual operation. Due to the inconsistency of the serial port levels (i.e., signal voltage and current levels) of each device in the UPS system, the communication quality between the UPS system and the monitoring system will be poor, resulting in frequent frame loss or bit errors. Poor communication quality between the UPS system and the monitoring system may cause the monitoring system to be unable to accurately obtain the status of the UPS system, causing adverse effects on the operation and maintenance of the UPS system, and increasing the difficulty and operation risk of the UPS system.

[0042] In this regard, the present invention provides a feeder protection device. The feeder protection device provided by the present invention can perform timing and effective feeder protection on the feeder circuit of the UPS system. When a feeder circuit fails, the faulty feeder circuit can be quickly cut off without affecting the operation of other normally operating feeder circuits. The safe and reliable operation of communication, signal, integrated monitoring and other equipment in the urban rail transit system is guaranteed.

[0043] Compared with the traditional thermal magnetic tripping molded case circuit breakers and / or air switches, the feeder protection function equipped in the feeder protection device provided by the present invention has centralized integration of the feeder protection function, with higher action value accuracy, which effectively improves the problem of large errors in thermal magnetic tripping molded case circuit breakers and / or air switches. The most prominent feature of the feeder protection device provided by the present invention is that the voltage criterion is introduced into the overcurrent protection, which effectively lowers the overcurrent protection setting threshold, and is more suitable for UPS systems, which use IGBT power devices for inverter output of AC circuit relay protection, and greatly improves the reliability and sensitivity of the feeder protection for the feeder circuit of the UPS system.

[0044] In addition, the feeder protection device provided by the present invention integrates the two major functions of time-sharing power-off and background communication required by the UPS system. The functional structure of the feeder protection device is clearer, the equipment configuration is optimized, the reliability and stability of the equipment are improved, and operation and maintenance are more convenient.

[0045] The feeder protection device provided by the present invention is a new type of feeder protection device, which improves and enhances the feeder protection function, makes the operation of UPS power supply and urban rail transit system more stable, provides more reliable working power supply for important equipment such as communication, signal, integrated monitoring, AFC, PIS in urban rail transit system, and provides reliable support for the safe operation of rail transit.

[0046] Combine the following Figure 1-Figure 3 The feeder protection device of the present invention is described.

[0047] Figure 1 This is one of the structural diagrams of the feeder protection device provided by the present invention. Figure 1As shown, the feed protection device 101 includes: a data acquisition module 102, a controller 103 and a switch control module 104; the data acquisition module 102, the controller 103 and the switch control module 104 are electrically connected in sequence.

[0048] The data acquisition module 102 is used to obtain the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the uninterruptible power supply UPS system and the digital signal corresponding to the current value of each phase of the alternating current in each feeder circuit, and then send the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and the digital signal corresponding to the current value of each phase of the alternating current in each feeder circuit to the controller 103. The UPS system supplies power to each load device in the urban rail transit system through each feeder circuit.

[0049] The controller 103 is used to determine whether an overcurrent occurs in each feeder circuit based on a digital signal corresponding to a phase voltage value of each phase of the AC power output by the UPS system and a digital signal corresponding to a current value of each phase of the AC power in each feeder circuit when each feeder circuit is in an overcurrent protection state, and to control the switch control module 104 to cut off the connection between the UPS system and any feeder circuit when it is determined that an overcurrent occurs in any feeder circuit.

[0050] The switch control module 104 is used to cut off the connection between the UPS system and any feed-out circuit in response to the control of the controller 103 .

[0051] It should be noted that the feeding protection device 101 in the embodiment of the present invention can perform feeding protection on the above-mentioned feeder circuits when the feeding protection of each feeder circuit between the UPS system and the urban rail transit system is triggered. The above-mentioned UPS system can supply power to the load equipment in the urban rail transit system through the above-mentioned feeder circuits. It can be understood that the feeder circuits of the UPS system correspond one-to-one to the load equipment in the urban rail transit system.

[0052] The operation and maintenance personnel of the urban rail transit system can trigger the feeding protection device 101 to perform feeding protection on the urban rail transit system by inputting control instructions.

[0053] It can be understood that, when the power feeding protection of each power feeding circuit between the UPS system and the urban rail transit system is triggered, the above-mentioned power feeding circuits are in the power feeding protection state.

[0054] It should be noted that the feeder protection in the embodiment of the present invention includes overcurrent protection and / or overload protection. Accordingly, when the overcurrent protection of each feeder circuit between the UPS system and the urban rail transit system is triggered, each of the feeder circuits is in an overcurrent protection state. When the overload protection of each feeder circuit between the UPS system and the urban rail transit system is triggered, each of the feeder circuits is in an overload protection state.

[0055] It should be noted that the AC power output by the UPS system in the embodiment of the present invention is three-phase AC power, and the three-phase AC power output by the UPS system includes A-phase AC power, B-phase AC power and C-phase AC power.

[0056] The data acquisition module 102 is configured with at least three AC voltage acquisition channels and a first number of AC current acquisition channels. The data acquisition module 102 can be used to collect the voltage value of the A-phase AC power, the voltage value of the B-phase AC power, and the voltage value of the C-phase AC power output by the UPS system in real time, as well as the current value of the A-phase AC power, the current value of the B-phase AC power, and the current value of the C-phase AC power in each feeder loop, and then the data acquisition module 102 can convert the real-time collected voltage value of the A-phase AC power, the voltage value of the B-phase AC power, and the voltage value of the C-phase AC power output by the UPS system, as well as the current value of the A-phase AC power, the current value of the B-phase AC power, and the current value of the C-phase AC power in each feeder loop into a digital signal that can be processed by the controller 103, and play a role in electrical isolation.

[0057] It should be noted that the first number in the embodiment of the present invention can be determined based on actual needs. For example, if the number of feeder circuits that need to be protected between the UPS system and the urban rail transit system is 10, then the first number is not less than 30. The specific value of the first number is not limited in the embodiment of the present invention.

[0058] As an optional embodiment, the data acquisition module 102 includes a voltage transformer and an analog-to-digital converter. The voltage transformer is connected to the UPS system and the analog-to-digital converter respectively, and the analog-to-digital converter is connected to the controller 103 .

[0059] The voltage transformer is used to obtain the test voltage value of each phase of the AC power output by the UPS system based on the phase voltage value of each phase of the AC power output by the UPS system, and then send the test voltage value of each phase of the AC power output by the UPS system to the analog-to-digital converter.

[0060] The analog-to-digital converter is used to generate a phase voltage value of each phase of the AC power output by the UPS system based on the test voltage value of each phase of the AC power output by the UPS system, and then send the phase voltage value of each phase of the AC power output by the UPS system to the controller 103.

[0061] Specifically, a potential transformer (PT) is a transformer with an iron core, similar to a transformer, and is mainly used to power measuring instruments and relay protection devices, and to measure the voltage, power and electric energy of the line. The voltage transformer is mainly composed of primary and secondary coils (windings), an iron core and an insulating part. The voltage transformer has two windings, one is called the primary winding (P) and the other is called the secondary winding (S). The working principle of the voltage transformer is based on the principle of electromagnetic induction. When the high-voltage side winding is connected to the power grid, the voltage in the power grid will cause current in the high-voltage winding, and through electromagnetic induction, current will also be generated in the low-voltage winding. The ratio of the current induced in the two windings is proportional to the turns ratio of the windings. By controlling the turns ratio of the windings, the voltage signal can be amplified or transformed, and the voltage signal in the high-voltage power grid can be converted into a low-voltage signal suitable for operation and measurement.

[0062] A voltage transformer disconnection refers to a disconnection fault on the primary or secondary side of a voltage transformer in a power system, which causes the voltage transformer to fail to work properly.

[0063] In the embodiment of the present invention, before the voltage transformer collects the phase voltage value of each phase of the alternating current output by the UPS system, the controller 103 can detect whether the voltage transformer is disconnected based on the status information of the voltage transformer.

[0064] The controller 103 can obtain the phase voltage value of each phase of the AC power currently collected by the voltage transformer through control instructions. If the controller 103 determines that the phase voltage value of any phase of the AC power currently collected by the voltage transformer is 0 or the voltages of the three-phase AC power are inconsistent, it can be determined that the voltage transformer is broken.

[0065] The controller 103 can also obtain the active power of each phase of AC power currently collected by the voltage transformer through control instructions. If the controller 103 determines that the active power of any phase of AC power currently collected by the voltage transformer is 0, it can be determined that the voltage transformer is disconnected.

[0066] The controller 103 can also monitor the alarm information output by the voltage transformer through the control instruction. If the controller 103 monitors that the voltage transformer outputs the alarm information indicating that the voltage transformer is disconnected, it can be determined that the voltage transformer is disconnected.

[0067] When the controller 103 determines that the voltage transformer is not disconnected and the feeding protection device 101 has been triggered to protect the urban rail transit system, the controller 103 triggers the voltage transformer through a control instruction. The triggered voltage transformer can convert the phase voltage value of each phase of the AC power output by the UPS system from a high voltage to a test voltage value of each phase of the AC power output by the UPS system at a low voltage.

[0068] After acquiring the test voltage value of each phase of the alternating current output by the UPS system, the voltage transformer may send the test voltage value of each phase of the alternating current output by the UPS system to the analog-to-digital converter.

[0069] The analog-to-digital converter can perform analog-to-digital conversion on the test voltage value of each phase of AC power output by the UPS system, and after converting the test voltage value of each phase of AC power output by the UPS system into a digital signal, it serves as a digital signal corresponding to the phase voltage value of each phase of AC power output by the UPS system.

[0070] It should be noted that the data acquisition module 102 in the embodiment of the present invention may also include a current sensor.

[0071] When the controller 103 determines that the feeding protection device 101 has triggered the feeding protection of the urban rail transit system, it triggers the current sensor through a control instruction. The triggered current sensor can collect the current value of each phase of the alternating current in each feeding loop.

[0072] After collecting the current value of each phase of the alternating current in each feeding loop, the current sensor may send the current value of each phase of the alternating current in each feeding loop to the analog-to-digital converter.

[0073] The analog-to-digital converter can perform analog-to-digital conversion on the current value of each phase of the alternating current in each feeding circuit, and after converting the current value of each phase of the alternating current in each feeding circuit into a digital signal, serve as a digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit.

[0074] After receiving the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system and the digital signal corresponding to the current value of each phase of the AC power in each feeding circuit sent by the data acquisition module 102, the controller 103 can restore the phase voltage value of each phase of the AC power output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system and the voltage reduction coefficient of the voltage transformer, and can also restore the current value of each phase of the AC power in each feeding circuit based on the digital signal corresponding to the current value of each phase of the AC power in each feeding circuit.

[0075] After obtaining the phase voltage value of each phase of the AC power output by the UPS system and the current value of each phase of the AC power in each feeding circuit, the controller 103 can determine whether overcurrent occurs in each feeding circuit through numerical calculation, mathematical statistics, and conditional judgment based on the phase voltage value of each phase of the AC power output by the UPS system and the current value of each phase of the AC power in each feeding circuit.

[0076] The controller 103 determines the first i When an overcurrent occurs in a feed-out circuit, the switch control module 104 can be controlled by a control instruction to cut off the UPS system from the first feed-out circuit. i The connection between the feed loops. , Indicates the total number of outgoing feeder circuits between the UPS system and the urban rail transit system.

[0077] As an optional embodiment, the controller 103 is used to control the switch control module 104 to cut off the connection between the UPS system and any feeder circuit after delaying the second delayed power-off time corresponding to any feeder circuit when it is determined that any feeder circuit has an overcurrent. The second delayed power-off time corresponding to each feeder circuit is predefined.

[0078] Specifically, the controller 103 determines the i When an overcurrent occurs in a feed-out circuit, the i From the moment when the first feed-out circuit has an overcurrent, the delay i After the second delay power-off time corresponding to the first feed-out circuit, the switch control module 104 is controlled by a control instruction to cut off the UPS system and the first feed-out circuit. i A connection for the feed-out loop.

[0079] It should be noted that the second delayed power-off duration corresponding to each feeder loop in the embodiment of the present invention may be predefined based on prior knowledge and / or actual conditions. The second delayed power-off duration corresponding to each feeder loop in the embodiment of the present invention is not specifically limited.

[0080] It should be noted that the feeder circuit in the embodiment of the present invention is provided with a thermal magnetic release molded case circuit breaker and / or an air switch. The connection state between the feeder circuit and the UPS system can be controlled by the thermal magnetic release molded case circuit breaker and / or the air switch.

[0081] The switch control module 104 in the embodiment of the present invention is configured with at least a second number of switch inputs and at least a third number of switch outputs. The switch control module 104 can introduce the switch position of the thermal magnetic tripping molded case circuit breaker and / or air switch arranged in each feeder circuit into the feeder protection device 101, and lead the trip output node of the feeder protection device 101 to the shunt coil of the switch.

[0082] It should be noted that the second number and the third number in the embodiment of the present invention can be determined based on actual needs. For example, if the number of thermal magnetic release type molded case circuit breakers and air switches in the feeder circuit to be protected between the UPS system and the urban rail transit system is 18, then the second number is not less than 36, and the third number is not less than 18. The specific values ​​of the second number and the third number are not limited in the embodiment of the present invention.

[0083] Accordingly, the switch control module 104 may collect status information of the thermal-magnetic release molded case circuit breaker and / or air switch provided in each feeder circuit.

[0084] The switch control module 104 receives the signal from the controller 103 for instructing to disconnect the UPS system from the i In the case of a control instruction for connecting the first and second feeding loops, the switch control module 104 can control the switch set at the first i The thermal magnetic release molded case circuit breaker and / or air switch in the first feeder circuit is disconnected, thereby cutting off the UPS system from the first feeder circuit. i The connection between the feed loops.

[0085] The feeder protection device in the embodiment of the present invention can judge whether an overcurrent occurs in each feeder circuit based on the phase voltage value of each phase of AC power output by the UPS system and the current value of each phase of AC power in each feeder circuit for supplying power to load equipment in the urban rail transit system by the UPS system, and cut off the connection between the UPS system and the above feeder circuit when it is determined that an overcurrent occurs in any feeder circuit. By combining the current judgment criterion and the voltage judgment criterion, the defect that the thermal magnetic tripping molded case circuit breaker and / or the air switch arranged in the above faulty feeder circuit cannot be successfully triggered to trip due to the output current limitation of the UPS system in the case of a feeder circuit failure can be overcome, thereby resulting in the failure to timely and effectively cut off the faulty feeder circuit in the urban rail transit system. The faulty feeder circuit in the urban rail transit system can be cut off more timely and effectively, the influence of the faulty feeder circuit on other non-faulty feeder circuits can be reduced, the influence range of the faulty feeder circuit can be better controlled, and the operation stability of the UPS system and the urban rail transit can be improved.

[0086] As an optional embodiment, the controller 103 is specifically used to determine, based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, that the voltage transformer is not broken at the current moment; if, based on the digital signal corresponding to the current value of any phase of the AC power in any feeding circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the AC power output by the UPS system, it is determined that the current value of any phase of the AC power in any feeding circuit at any historical moment exceeds a predefined first current threshold and the line voltage value of any phase of the AC power output by the UPS system at the current moment is lower than a predefined first voltage threshold, then it is determined that overcurrent has occurred in any feeding circuit, and the duration of the interval between any historical moment and the current moment does not exceed the preset duration.

[0087] Figure 2 FIG. 1 is a logic diagram of the overcurrent protection performed by the feeder protection device provided by the present invention. Figure 2 As shown, the controller 103 can obtain the phase voltage value of each phase of the AC power output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, and further can determine whether the voltage transformer is broken at the current moment based on the phase voltage value of each phase of the AC power output by the UPS system.

[0088] It should be noted that, when the controller 103 determines that the phase voltage value of any phase of the AC power currently output by the UPS system is 0 based on the phase voltage value of each phase of the AC power currently output by the UPS system, the controller 103 can determine that the voltage transformer is broken; when the controller 103 determines that the phase voltage values ​​of any two phases of the AC power currently output by the UPS system are unequal based on the phase voltage value of each phase of the AC power currently output by the UPS system, the controller 103 can determine that the voltage transformer is broken.

[0089] For the first connection between UPS system and urban rail transit system i The controller 103 can determine that the voltage transformer is not disconnected based on the first feed-out loop. j Historical Moments i The digital signal corresponding to the current value of the A-phase AC in the first feeding circuit is obtained. j Historical Moments i The current value of the A-phase AC in the first feeding circuit. j The duration between the historical moment and the current moment does not exceed the preset duration. j Can represent any positive integer.

[0090] The controller 103 obtains the j Historical Moments i After the current value of phase A AC in the first feed-out circuit is determined, the j Historical Momentsi Whether the current value of the A-phase AC power in the first feeding loop exceeds a predefined first current threshold.

[0091] If the controller 103 determines j Historical Moments i If the current value of the A-phase AC power in the first feeding loop exceeds the predefined first current threshold, the j The historical moment is recorded as the failure moment and will be j The preset time period from the historical moment is determined as the failure period.

[0092] During the above-mentioned fault period, the controller 103 can obtain the phase voltage value of each phase of AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase of AC power currently output by the UPS system, and then can calculate the line voltage value Uab and line voltage value Uca of the A-phase AC power currently output by the UPS system based on the phase voltage value of each phase of AC power currently output by the UPS system. Among them, the line voltage value Uab of the A-phase AC power currently output by the UPS system is the absolute value of the difference between the voltage value of the A-phase AC power currently output by the UPS system and the voltage value of the B-phase AC power; the line voltage value Uca of the A-phase AC power currently output by the UPS system is the absolute value of the difference between the voltage value of the A-phase AC power currently output by the UPS system and the voltage value of the C-phase AC power.

[0093] During the above fault period, after the controller 103 obtains the line voltage value Uab and the line voltage value Uca of the A-phase AC power currently output by the UPS system, it can be determined whether the line voltage value Uab and the line voltage value Uca of the A-phase AC power currently output by the UPS system obtained by the controller 103 are lower than the predefined first voltage threshold value Uzd. If the controller 103 determines that the line voltage value Uab or the line voltage value Uca of the A-phase AC power currently output by the UPS system is lower than the first voltage threshold value Uzd, the controller 103 can determine the first voltage threshold value Uzd. i An overcurrent occurs in a feed-out circuit.

[0094] Similarly, when the controller 103 determines that the voltage transformer is not disconnected based on the digital signal corresponding to the phase voltage value of each phase of the AC power currently output by the UPS system, the controller 103 can j Historical Moments i The digital signal corresponding to the current value of the B-phase AC in the first feeding circuit is used to determine the j Historical Moments i Whether the current value of the B-phase AC power in the first feed-out loop exceeds a predefined first current threshold, the controller 103 determines whether the first j Historical Moments iWhen the current value of the B-phase AC power in the first feeding loop exceeds the predefined first current threshold, the controller 103 can j The controller 103 can obtain the line voltage value Uab and the line voltage value Ubc of the B-phase AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase AC power currently output by the UPS system within the fault period of the preset time length from the historical moment, and then determine the first voltage threshold Uzd when determining that the line voltage value Uab or the line voltage value Ubc of the B-phase AC power currently output by the UPS system is lower than the first voltage threshold Uzd. i An overcurrent occurs in the feeder circuit. Among them, the line voltage value Uab of the B-phase AC output by the UPS system at the current moment is the absolute value of the difference between the voltage value of the A-phase AC output by the UPS system at the current moment and the voltage value of the B-phase AC output by the UPS system at the current moment; the line voltage value Ubc of the B-phase AC output by the UPS system at the current moment is the absolute value of the difference between the voltage value of the B-phase AC output by the UPS system at the current moment and the voltage value of the C-phase AC output by the UPS system.

[0095] Similarly, when the controller 103 determines that the voltage transformer is not disconnected based on the digital signal corresponding to the phase voltage value of each phase of the AC power currently output by the UPS system, the controller 103 can j Historical Moments i The digital signal corresponding to the current value of the C-phase AC in the first feeding circuit is used to determine the j Historical Moments i Whether the current value of the C-phase AC power in the first feed-out loop exceeds a predefined first current threshold, the controller 103 determines whether the first j Historical Moments i When the current value of the C-phase AC power in the first feeding loop exceeds the predefined first current threshold, the controller 103 can j The controller 103 can obtain the line voltage value Ubc and the line voltage value Uca of the C-phase AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase AC power currently output by the UPS system within the fault period of the preset time length from the historical moment, and then determine the first voltage threshold Uzd when determining that the line voltage value Ubc and the line voltage value Uca of the C-phase AC power currently output by the UPS system are lower than the first voltage threshold Uzd. i An overcurrent occurs in a feeder circuit. Among them, the line voltage value Ubc of the C-phase AC power currently output by the UPS system is the absolute value of the difference between the voltage value of the B-phase AC power currently output by the UPS system and the voltage value of the C-phase AC power; the line voltage value Uca of the C-phase AC power currently output by the UPS system is the absolute value of the difference between the voltage value of the C-phase AC power currently output by the UPS system and the voltage value of the A-phase AC power.

[0096] It is understandable that the controller 103 in the embodiment of the present invention is configured with a timing function.

[0097] It should be noted that the first current threshold and the first voltage threshold in the embodiment of the present invention may be determined based on actual conditions and / or prior knowledge. The specific values ​​of the first current threshold and the first voltage threshold in the embodiment of the present invention are not limited.

[0098] It should be noted that the first delayed power-off duration corresponding to each feeder loop in the embodiment of the present invention may be predefined based on prior knowledge and / or actual conditions. The first delayed power-off duration corresponding to each feeder loop in the embodiment of the present invention is not specifically limited.

[0099] The controller in the feeder protection device in the embodiment of the present invention can determine, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system, that the voltage transformer is not disconnected at the current moment. If, based on the digital signal corresponding to the current value of any phase of the alternating current in any feeder circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the alternating current output by the UPS system, it is determined that the current value of any phase of the alternating current in any feeder circuit at any historical moment exceeds a predefined first current threshold and the line voltage value of any phase of the alternating current output by the UPS system at the current moment is lower than the predefined first voltage threshold, then it is determined that any feeder circuit has an overcurrent. This can better overcome the defect that, in the event of a feeder circuit failure, the thermal-magnetic release molded case circuit breaker and / or air switch arranged in the above-mentioned faulty feeder circuit cannot be successfully triggered to trip due to the UPS system limiting the output current, thereby further improving the timeliness and effectiveness of cutting off the faulty feeder circuit in the urban rail transit system, and further reducing the impact of the faulty feeder circuit on the remaining non-faulty feeder circuits.

[0100] As an optional embodiment, the controller 103 is specifically used to determine, based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, that the voltage transformer is not broken at the current moment; if, based on the digital signal corresponding to the current value of any phase of the AC power in any feeding circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the AC power output by the UPS system at the current moment, it is determined that the current value of any phase of the AC power in any feeding circuit at any historical moment exceeds a predefined second current threshold and the phase voltage value of any phase of the AC power output by the UPS system at the current moment is lower than a predefined second voltage threshold, then it is determined that overcurrent occurs in any feeding circuit, and the duration between any historical moment and the current moment does not exceed the preset duration.

[0101] Specifically, the controller 103 can obtain the phase voltage value of each phase of AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of each phase of AC power currently output by the UPS system, and then determine whether the voltage transformer is broken based on the phase voltage value of each phase of AC power currently output by the UPS system.

[0102] For the first connection between UPS system and urban rail transit system i The controller 103 can determine that the voltage transformer is not disconnected based on the first feed-out loop. j Historical Moments i The digital signal corresponding to the current value of the A-phase AC in the first feeding circuit is obtained. j Historical Moments i The current value of phase A AC in the feed-out circuit.

[0103] The controller 103 obtains the j Historical Moments i After the current value of phase A AC in the first feed-out circuit is determined, the j Historical Moments i Whether the current value of the A-phase alternating current in the first feeding loop exceeds a predefined second current threshold.

[0104] If the controller 103 determines j Historical Moments i If the current value of the A-phase AC power in the first feeding circuit exceeds the second current threshold, the j The historical moment is recorded as the failure moment and will be j The preset time period from the historical moment is determined as the failure period.

[0105] During the above fault period, the controller 103 can obtain the phase voltage value of the A-phase AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of the A-phase AC power currently output by the UPS system, and then determine whether the phase voltage value of the A-phase AC power currently output by the UPS system is less than the predefined second voltage threshold. If the controller 103 determines that the phase voltage value of the A-phase AC power currently output by the UPS system is less than the second voltage threshold, the controller 103 can determine the second voltage threshold. i An overcurrent occurs in a feed-out circuit.

[0106] Similarly, when the controller 103 determines that the voltage transformer is not disconnected based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, the controller 103 can j Historical Moments i The digital signal corresponding to the current value of the B-phase AC in the first feeding circuit is used to determine the jHistorical Moments i If the current value of the B-phase AC power in the first feed-out loop exceeds the predefined second current threshold, the controller 103 determines that j Historical Moments i If the current value of the B-phase AC power in the first feeding loop exceeds the second current threshold, the controller 103 can j The controller 103 can obtain the phase voltage value of the B-phase AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of the B-phase AC power currently output by the UPS system within the fault period of the preset time length from the historical moment, and then determine the first fault condition when determining that the phase voltage value of the B-phase AC power currently output by the UPS system is lower than the second voltage threshold. i An overcurrent occurs in a feed-out circuit.

[0107] Similarly, when the controller 103 determines that the voltage transformer is not disconnected based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, the controller 103 can j Historical Moments i The digital signal corresponding to the current value of the C-phase AC in the first feeding circuit is used to determine the j Historical Moments i If the current value of the C-phase AC power in the first feed-out loop exceeds the predefined second current threshold, the controller 103 determines that j Historical Moments i If the current value of the C-phase AC power in the first feeding loop exceeds the second current threshold, the controller 103 can j The controller 103 can obtain the phase voltage value of the C-phase AC power currently output by the UPS system based on the digital signal corresponding to the phase voltage value of the C-phase AC power currently output by the UPS system within the fault period of the preset time length from the historical moment, and then determine the first fault condition when determining that the phase voltage value of the C-phase AC power currently output by the UPS system is lower than the second voltage threshold. i An overcurrent occurs in a feed-out circuit.

[0108] It should be noted that the second current threshold and the second voltage threshold in the embodiment of the present invention may be determined based on actual conditions and / or prior knowledge. The specific values ​​of the second current threshold and the second voltage threshold in the embodiment of the present invention are not limited.

[0109] The controller in the feeder protection device in the embodiment of the present invention can determine, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system, that the voltage transformer is not disconnected at the current moment. If, based on the digital signal corresponding to the current value of any phase of the alternating current in any feeder circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the alternating current output by the UPS system at the current moment, it is determined that the current value of any phase of the alternating current in any feeder circuit at any historical moment exceeds the predefined second current threshold and the phase voltage value of any phase of the alternating current output by the UPS system at the current moment is lower than the predefined second voltage threshold, then it is determined that any feeder circuit has an overcurrent. This can better overcome the defect that, in the case of a feeder circuit failure, the thermal magnetic release molded case circuit breaker and / or air switch arranged in the above-mentioned faulty feeder circuit cannot be successfully triggered to trip due to the UPS system limiting the output current, thereby further improving the timeliness and effectiveness of cutting off the faulty feeder circuit in the urban rail transit system, and further reducing the impact of the faulty feeder circuit on the remaining non-faulty feeder circuits.

[0110] As an optional embodiment, the controller 103 is also used to determine whether the voltage transformer has a line break based on a digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, or, when it is determined that the voltage transformer has triggered a line break lockout protection, control the switch control module 104 to cut off the connection between the UPS system and each feeding circuit.

[0111] When the controller 103 determines that the voltage transformer is disconnected based on the digital signal corresponding to the phase voltage value of each phase of the AC power output by the UPS system, it can control the switch control module 104 to cut off the connection between the UPS system and each feeding circuit through control instructions.

[0112] When the controller 103 determines that the voltage transformer triggers the line break lockout protection based on the status information of the voltage transformer, it can control the switch control module 104 to cut off the connection between the UPS system and each feeder circuit through a control instruction.

[0113] As an optional embodiment, the controller 103 is also used to determine whether each feeder circuit is overloaded based on the digital signal corresponding to the current value of each phase of AC power in each feeder circuit when each feeder circuit is in an overload protection state, and control the switch control module 104 to cut off the connection between the UPS system and any feeder circuit when it is determined that any feeder circuit is overloaded.

[0114] Specifically, the controller 103 is also used to determine that any feeding circuit is overloaded when the current value of any phase of the AC power in any feeding circuit at the current moment exceeds a predefined third current threshold based on the digital signal corresponding to the current value of any phase of the AC power in any feeding circuit.

[0115] For the first connection between UPS system and urban rail transit system i The controller 103 is based on the current moment i The digital signal corresponding to the current value of the A-phase AC in the first feeding circuit determines the current value of the i When the current value of the A-phase AC power in the first feeding circuit exceeds the predefined third current threshold, the i An outgoing circuit is overloaded.

[0116] Similarly, the controller 103 is based on the current moment i The digital signal corresponding to the current value of the B-phase AC in the first feeding loop determines the current value of the i When the current value of the B-phase AC power in the first feeding circuit exceeds the predefined third current threshold, the i An outgoing circuit is overloaded.

[0117] Similarly, the controller 103 is based on the current moment i The digital signal corresponding to the current value of the C-phase AC in the first feeding loop determines the current value of the i When the current value of the C-phase AC power in the first feeding loop exceeds the predefined third current threshold, the i An outgoing circuit is overloaded.

[0118] The controller 103 is used to control the switch control module 104 to cut off the connection between the UPS system and any feeder circuit after delaying the third delayed power-off time corresponding to any feeder circuit when it is determined that any feeder circuit is overloaded. The third delayed power-off time corresponding to each feeder circuit is predefined.

[0119] The controller in the feeder protection device in the embodiment of the present invention can, when each feeder circuit is in an overload protection state, determine whether each feeder circuit is overloaded based on the digital signal corresponding to the current value of each phase of the alternating current in each feeder circuit, and when it is determined that any feeder circuit is overloaded, control the switch control module 104 to cut off the connection between the UPS system and any feeder circuit, thereby improving the operating stability of urban rail transit.

[0120] As an optional embodiment, the controller 103 is also used to control the switch control module 104 to respectively cut off the connection between the UPS system and each feeder circuit after delaying the first delayed power-off time corresponding to each feeder circuit, when it is determined that the UPS system is operating in the battery inverter mode based on the status information of the UPS system. The first delayed power-off time corresponding to each feeder circuit is predefined.

[0121] It should be noted that when there is a problem with the mains power supply or the mains power does not meet the input requirements of the UPS system, the UPS system can switch to the battery inverter mode. When the UPS system is running in the battery inverter mode, the DC power in the battery in the UPS system can be converted into AC power through the inverter to maintain continuous power supply to the load equipment.

[0122] The controller 103 can obtain the status information of the UPS system through control instructions, and when it is determined that the UPS system is operating in the battery inverter mode based on the status information of the UPS system, it can control the switching control module to cut off the connection between the UPS system and each feeder circuit after delaying the first delayed power-off time corresponding to each feeder circuit since the moment when the UPS system is determined to be operating in the battery inverter mode.

[0123] It should be noted that, when there are multiple UPS systems, each UPS system supplies power to the load equipment in the urban rail transit system in parallel. When the controller 103 determines that each UPS system is operating in the battery inverter mode based on the status system of each UPS system, from the moment when the UPS system is determined to be operating in the battery inverter mode, after delaying the first delayed power-off time corresponding to each feed-out circuit, the controller 103 controls the switching control module through a control instruction to cut off the connection between the UPS system and each feed-out circuit.

[0124] It should be noted that the setting ranges of the phase voltage value of each phase of AC power output by the UPS system in the embodiment of the present invention, the test voltage of each phase of AC power output by the UPS system, and the current value of each phase of AC power in each feed-out circuit are shown in Table 1. The setting ranges of the first voltage threshold, the first delayed power-off time, the second delayed power-off time, and the third delayed power-off time corresponding to the feed-out circuit are shown in Table 1.

[0125] The setting range in the UPS system in the embodiment of the present invention is shown in Table 1.

[0126] Table 1 Protection setting table

[0127] It should be noted that the control word in Table 1 is used to indicate whether the relevant functions are triggered. For example, when the control word corresponding to triggering the voltage transformer line break lockout protection is "1", it means that the voltage transformer line break lockout protection has been triggered. When the control word corresponding to triggering the voltage transformer line break lockout protection is "0", it means that the voltage transformer line break lockout protection has not been triggered.

[0128] The controller in the feeder protection device in the embodiment of the present invention can, when determining that the UPS system is operating in the battery inverter mode, control the switch control module to respectively cut off the connection between the UPS system and each feeder circuit after delaying the first delayed power-off time corresponding to each feeder circuit. In the event of a mains power abnormality, the controller can control different types of load equipment in the urban rail transit system to power off in different times. It can shut down unnecessary load equipment in the urban rail transit system by powering off in different times to save electricity, thereby extending the operating time of the core system in the urban rail transit system. In the event of a mains power abnormality, it can provide a longer emergency processing time for the emergency processing of the urban rail transit system.

[0129] Figure 3 This is the second structural diagram of the feeder protection device provided by the present invention. Figure 3 As shown, as an optional embodiment, the feeder protection device 101 also includes: a communication module 301; the communication module 301 includes multiple RS485 serial ports, several RJ45 Ethernet interfaces and a communication protocol conversion module, and each RS485 serial port is connected to each RJ45 Ethernet interface through the communication protocol conversion module.

[0130] The RS485 serial port is used to connect sub-devices in the UPS system.

[0131] RJ45 is used to connect the monitoring system, which is used to monitor the operating status of the UPS system.

[0132] The communication protocol conversion module is used to convert the communication protocol of the input data.

[0133] It should be noted that the sub-devices in the UPS system in the embodiment of the present invention may include but are not limited to a UPS host, an incoming feeder cabinet, a bypass cabinet, a feeder cabinet, a voltage stabilizing cabinet, a PLC, an electric meter, and a battery inspection instrument.

[0134] The sub-devices in the UPS system need to communicate with the monitoring system so that the monitoring system can obtain the operating status and data of each device in the UPS system in real time.

[0135] Optionally, in the embodiment of the present invention, the number of RS485 serial ports can be determined based on the number of sub-devices that need to be monitored in the UPS system. For example, the number of RS485 serial ports can be 4 to 8, for example, the number of RS485 serial ports can be 4, 6 or 8.

[0136] Optionally, the number of the RJ45 Ethernet interface in the embodiment of the present invention may be 1.

[0137] Each sub-device in the UPS system can be connected to each RS485 serial port using the MODBUS RTU protocol. Each sub-device in the UPS system uses an independent RS485 serial port for communication, which realizes the physical isolation of the serial port, effectively eliminates the communication interference of the multi-serial port hand-in-hand mode, and improves the communication quality.

[0138] Each RS485 serial port sends the received data to the communication protocol conversion module.

[0139] The communication protocol conversion module can convert the data sent by the RS485 serial port from the MODBUS RTU protocol to the MODBUS TCP protocol, and then send it to the monitoring system through the RJ45 Ethernet interface, so that the monitoring system can monitor the operating status of the UPS system based on the received data.

[0140] The communication module of the feeder protection device in the embodiment of the present invention includes multiple independent RS485 serial ports and RJ45 Ethernet ports, which can realize physical isolation of the serial ports, effectively eliminate the communication interference of the multi-serial port hand-in-hand mode, improve the communication quality between the UPS system and the monitoring system, improve the monitoring effect of the monitoring system on the UPS system, and improve the operation stability of the urban rail transit system.

[0141] As an optional embodiment, the feeding protection device 101 further includes: a display device 302 ; the display device 302 is electrically connected to the controller 103 .

[0142] The controller 103 is also used to control the display device 302 to display an alarm message for prompting that any feeding circuit has an overcurrent when it is determined that any feeding circuit has an overcurrent at the current moment. The controller 103 is also used to control the display device 302 to display target information, and the target information includes at least one of the phase voltage value of each phase of the AC power output by the UPS system, the current value of each phase of the AC power in each feeding circuit, the first current threshold value, and the first delayed power-off time corresponding to each feeding circuit.

[0143] The display device 302 is used to display warning information in response to the control of the controller 103 . The display device 302 is also used to display target information in response to the control of the controller 103 .

[0144] Specifically, the controller 103 determines thei When an overcurrent occurs in a feed-out circuit, the display device 302 can also be controlled by a control instruction to display a display for indicating the first i The overcurrent alarm information of the feed-in circuit is displayed for the operation and maintenance personnel to check.

[0145] Similarly, the controller 103 determines the i When an overload occurs in a feed-out circuit, the display device 302 can also be controlled by a control instruction to display a display for indicating the first i The overload alarm information of each feeder circuit is displayed for the operation and maintenance personnel to check.

[0146] The controller 103 can also control the display device 302 to display at least one of the phase voltage value of each phase of AC power output by the UPS system, the current value of each phase of AC power in each feeding circuit, the first current threshold, and the first delayed power-off time corresponding to each feeding circuit through control instructions for viewing by operation and maintenance personnel.

[0147] The controller 103 can also control the display device 302 to display any one or more of the second delayed power-off time, the first current threshold, the second current threshold, the third current threshold, the first voltage threshold, the second voltage threshold and the third voltage threshold corresponding to each feed-out loop through control instructions for viewing by operation and maintenance personnel.

[0148] As an optional embodiment, the feed protection device 101 further includes: a power supply module 303 ; the power supply module 303 is used to supply power to the data acquisition module 102 , the controller 103 and the switch control module 104 .

[0149] It should be noted that if Figure 3 As shown, the data acquisition module 102 , the controller 103 , the switch control module 104 , the communication module 301 , the display device 302 and the power module 303 can realize data transmission and power supply through the motherboard 304 .

[0150] The feeder protection device provided by the present invention, when performing overcurrent protection on the feeder circuit between the UPS system and the urban rail transit system, adds a low voltage criterion of the alternating current output by the UPS system and a voltage transformer disconnection criterion on the basis of the traditional overcurrent protection function, and triggers the overcurrent protection only when the low voltage condition is met. After the voltage criterion is introduced, the setting value for triggering the overcurrent protection can be as small as possible, so that in the event of a fault in the feeder circuit, although the output current of the UPS system is limited to 120% or 150% of the rated current, it can still trigger the thermal magnetic release type molded case circuit breaker and / or air switch arranged in the feeder circuit to trip, thereby cutting off the connection between the faulty feeder circuit and the UPS system. The introduction of the low voltage criterion effectively solves the problem of the thermal magnetic release type molded case circuit breaker and / or air switch arranged in the feeder circuit refusing to operate due to the small current caused by the output current limiting of the UPS system.

[0151] Figure 4 FIG. 1 is a flow chart of the feeder protection method provided by the present invention. Figure 4 As shown, a feeding protection method implemented based on the above feeding protection device 101 includes: step 401, obtaining a digital signal corresponding to a phase voltage value of each phase of AC power output by a UPS system and a digital signal corresponding to a current value of each phase of AC power in each feeding circuit; Step 402: when each feeder circuit is in an overcurrent protection state, based on a digital signal corresponding to a phase voltage value of each phase of the AC power output by the UPS system and a digital signal corresponding to a current value of each phase of the AC power in each feeder circuit, determine whether an overcurrent occurs in each feeder circuit; Step 403: When it is determined that any feeder circuit has an overcurrent, the connection between the UPS system and any feeder circuit is cut off.

[0152] It should be noted that the feeder protection method provided by the present invention is implemented based on the feeder protection device 101 in the above embodiments. The specific execution steps of the feeder protection method provided by the present invention can refer to the contents of the above embodiments, which will not be repeated in the embodiments of the present invention.

[0153] The embodiment of the present invention determines whether an overcurrent occurs in each feeder circuit based on the phase voltage value of each phase of AC power output by the UPS system and the current value of each phase of AC power in each feeder circuit for supplying power to load equipment in the urban rail transit system by the UPS system, and cuts off the connection between the UPS system and the above feeder circuit when it is determined that an overcurrent occurs in any feeder circuit. By combining the current judgment criterion and the voltage judgment criterion, the defect that the thermal magnetic tripping molded case circuit breaker and / or the air switch arranged in the above faulty feeder circuit cannot be successfully triggered to trip due to the output current limitation of the UPS system in the case of a feeder circuit failure, thereby resulting in the failure to timely and effectively cut off the faulty feeder circuit in the urban rail transit system, the faulty feeder circuit in the urban rail transit system can be cut off more timely and effectively, the influence of the faulty feeder circuit on other non-faulty feeder circuits can be reduced, the influence range of the faulty feeder circuit can be better controlled, and the operation stability of the UPS system and the urban rail transit can be improved.

[0154] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530 and a communication bus 540, wherein the processor 510, the communication interface 520 and the memory 530 communicate with each other through the communication bus 540. The processor 510 may call the logic instructions in the memory 530 to execute the feeding protection method, which includes: obtaining a digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit; when each feeding circuit is in an overcurrent protection state, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and the digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit, determining whether each feeding circuit has an overcurrent; when it is determined that any feeding circuit has an overcurrent, cutting off the connection between the UPS system and any feeding circuit.

[0155] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0156] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by the processor 510, the computer can execute the feeding protection method provided by the above methods, which includes: obtaining a digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit; when each feeding circuit is in an overcurrent protection state, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and the digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit, determining whether an overcurrent occurs in each feeding circuit; when it is determined that an overcurrent occurs in any feeding circuit, cutting off the connection between the UPS system and any feeding circuit.

[0157] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by the processor 510, is implemented to execute the feeding protection method provided by the above-mentioned methods, the method comprising: obtaining a digital signal corresponding to a phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of the alternating current in each feeding circuit; when each feeding circuit is in an overcurrent protection state, judging whether an overcurrent occurs in each feeding circuit based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system and the digital signal corresponding to the current value of each phase of the alternating current in each feeding circuit; and when it is determined that an overcurrent occurs in any feeding circuit, cutting off the connection between the UPS system and any feeding circuit.

[0158] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0159] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A feeding protection device, characterized in that: include: Data acquisition module, controller and switch control module; The data acquisition module, the controller and the switch control module are electrically connected in sequence; The data acquisition module is used to obtain a digital signal corresponding to a phase voltage value of each phase of alternating current output by an uninterruptible power supply UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feeder circuit, and then send the digital signal corresponding to a phase voltage value of each phase of alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feeder circuit to the controller, and the UPS system supplies power to each load device in the urban rail transit system through each feeder circuit; The controller is used to determine whether an overcurrent occurs in each of the feeder circuits based on a digital signal corresponding to a phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of the alternating current in each feeder circuit when each of the feeder circuits is in an overcurrent protection state, and to control the switch control module to cut off the connection between the UPS system and any of the feeder circuits when it is determined that an overcurrent occurs in any of the feeder circuits; The switch control module is used to cut off the connection between the UPS system and any one of the feeder circuits in response to the control of the controller.

2. The feed protection device according to claim 1, characterized in that: The controller is specifically used to determine, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system, that the voltage transformer is not broken at the current moment; if, based on the digital signal corresponding to the current value of any phase of the alternating current in any feeding circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the alternating current output by the UPS system, it is determined that the current value of any phase of the alternating current in any feeding circuit at any historical moment exceeds a predefined first current threshold and the line voltage value of any phase of the alternating current output by the UPS system at the current moment is lower than a predefined first voltage threshold, then it is determined that an overcurrent occurs in any feeding circuit, and the duration of the interval between any historical moment and the current moment does not exceed a preset duration.

3. The feed protection device according to claim 2, characterized in that: The controller is also used to control the switch control module to respectively cut off the connection between the UPS system and each of the feeder circuits after delaying a first delayed power-off time corresponding to each of the feeder circuits, when it is determined that the UPS system is operating in a battery inverter mode based on status information of the UPS system, and the first delayed power-off time corresponding to each of the feeder circuits is predefined.

4. The feeder protection device according to claim 1, characterized in that: Also includes: Communication module; the communication module includes a plurality of RS485 serial ports, a plurality of RJ45 Ethernet interfaces and a communication protocol conversion module, each of the RS485 serial ports is connected to each of the RJ45 Ethernet interfaces via the communication protocol conversion module; The RS485 serial port is used to connect the sub-devices in the UPS system; The RJ45 is used to connect to a monitoring system, and the monitoring system is used to monitor the operating status of the UPS system; The communication protocol conversion module is used to convert the communication protocol of the input data.

5. The feeder protection device according to claim 1, characterized in that: The controller is used to control the switch control module to cut off the connection between the UPS system and any feeder circuit after delaying the second delayed power-off time corresponding to any feeder circuit when it is determined that any feeder circuit has an overcurrent, and the second delayed power-off time corresponding to each feeder circuit is predefined.

6. The feeder protection device according to claim 1, characterized in that: The data acquisition module includes a voltage transformer and an analog-to-digital converter; the voltage transformer is connected to the UPS system and the analog-to-digital converter respectively, and the analog-to-digital converter is connected to the controller; The voltage transformer is used to obtain a test voltage value of each phase of the AC power output by the UPS system based on a phase voltage value of each phase of the AC power output by the UPS system, and then send the test voltage value of each phase of the AC power output by the UPS system to the analog-to-digital converter; The analog-to-digital converter is used to generate a phase voltage value of each phase of the AC power output by the UPS system based on a test voltage value of each phase of the AC power output by the UPS system, and then send the phase voltage value of each phase of the AC power output by the UPS system to the controller.

7. The feeder protection device according to claim 1, characterized in that: The controller is specifically used to determine, based on the digital signal corresponding to the phase voltage value of each phase of the alternating current output by the UPS system, that the voltage transformer is not broken at the current moment; if, based on the digital signal corresponding to the current value of any phase of the alternating current in any feeding circuit at any historical moment and the digital signal corresponding to the phase voltage value of any phase of the alternating current output by the UPS system at the current moment, it is determined that the current value of any phase of the alternating current in any feeding circuit at any historical moment exceeds a predefined second current threshold and the phase voltage value of any phase of the alternating current output by the UPS system at the current moment is lower than a predefined second voltage threshold, then it is determined that overcurrent occurs in any feeding circuit, and the duration between any historical moment and the current moment does not exceed a preset duration.

8. The feeder protection device according to claim 1, characterized in that: The controller is also used to determine whether each of the feeder circuits is overloaded based on the digital signal corresponding to the current value of each phase of the AC power in each of the feeder circuits when each of the feeder circuits is in an overload protection state, and to control the switch control module to cut off the connection between the UPS system and any of the feeder circuits when it is determined that any of the feeder circuits is overloaded; The controller is also used to control the switch control module to cut off the connection between the UPS system and any feeder circuit after delaying a third delayed power-off time corresponding to any feeder circuit when it is determined that any feeder circuit is overloaded, and the third delayed power-off time corresponding to each feeder circuit is predefined.

9. The feed protection device according to claim 3, characterized in that: Also includes: Display device; the display device is electrically connected to the controller; The controller is further configured to, when determining that an overcurrent occurs at the current moment in any feeder circuit, control the display device to display an alarm message for prompting that an overcurrent occurs at the current moment in any feeder circuit, and the controller is further configured to control the display device to display target information, wherein the target information includes at least one of the voltage value of each phase, the current value of each phase, the first current threshold, and the first delayed power-off time length corresponding to each feeder circuit; The display device is used to display alarm information for prompting that overcurrent occurs in any of the feed-out circuits at the current moment in response to the control of the controller, and the display device is also used to display the target information in response to the control of the controller.

10. A feeding protection method implemented based on the feeding protection device according to any one of claims 1 to 9, characterized in that: include: Obtaining a digital signal corresponding to a phase voltage value of each phase of alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of alternating current in each feed-out circuit; When each of the feeder circuits is in an overcurrent protection state, judging whether an overcurrent occurs in each of the feeder circuits based on a digital signal corresponding to a phase voltage value of each phase of the alternating current output by the UPS system and a digital signal corresponding to a current value of each phase of the alternating current in each of the feeder circuits; When it is determined that an overcurrent occurs in any feeder circuit, the connection between the UPS system and any feeder circuit is cut off.

11. An electronic device comprising a memory, a controller, and a computer program stored in the memory and executable on the controller, wherein: When the controller executes the computer program, the feeder protection method as claimed in claim 10 is implemented.

12. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the controller, the feeder protection method as claimed in claim 10 is implemented.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by the controller, the feeder protection method as claimed in claim 10 is implemented.

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