Operation state monitoring system for double voltage transformers of traction substation

Abstract

The utility model discloses an operation state monitoring system for double voltage transformers of a traction substation, which relates to the technical field of traction power transformation and comprises a traction bus, two voltage transformers and two air switches. Each of the two voltage transformers comprises a primary winding and a secondary winding; the head ends of the two primary windings are connected to a traction bus, and the tail ends of the two primary windings are connected in series with a current transmitter and then are grounded; a current signal acquired by the current transmitter is accessed to an input loop of the PLC device; and the PLC device is used for analyzing the current signal and judging whether the voltage transformer has a fault or not. According to the utility model, abnormal current deviation or sudden current change of the voltage transformers due to faults can be observed or monitored, abnormal voltage or electric quantity protection maloperation or operation refusal caused by faults of the two voltage transformers can be avoided, the operation state of the double voltage transformers can be monitored, the fault rate of traction power transformation can be reduced, and the safety of traction power transformation can be improved. The traction substation power supply reliability is improved.

Description

Technical Field

[0001] This utility model relates to the field of railway traction substation instrument transformer technology, and in particular to an operation status monitoring system for dual voltage transformers in traction substations. Background Technology

[0002] The bus dual voltage transformer in the traction substation is a core device used to reliably collect the voltage of the traction substation bus. Its function is to proportionally transform the high voltage of the traction bus into a low voltage to supply power for protection, measurement and metering in the traction substation. Combined with the operation of protection devices, it ensures normal traction power supply.

[0003] In dual-voltage transformer operation mode, since the secondary windings of the two voltage transformers in the same phase are connected in parallel before being connected to the integrated automation system, the normal operation of either voltage transformer does not affect the voltage acquisition of the integrated automation system. For example, if one voltage transformer fails, the integrated automation system can still acquire voltage through the secondary winding of the other voltage transformer connected in parallel to the voltage bus. In the typical dual-voltage transformer operation mode described above, a fault in one voltage transformer can only be detected through routine inspections of the equipment's appearance or by performing voltage tests on the two terminals before and after the secondary circuit breaker of the voltage transformer. If a fault in one voltage transformer is not detected in time, and the other voltage transformer also fails, it will cause abnormal voltage acquisition by the corresponding protection device, leading to malfunctions or failures to trip the electrical protection device, potentially resulting in an interruption of traction power supply and severely disrupting transportation operations. Utility Model Content

[0004] The purpose of this invention is to address the problem in existing dual-voltage transformer systems where a fault in a single voltage transformer cannot be detected in a timely manner, leading to abnormal voltage acquisition by the integrated automation system and consequently causing maloperation or failure of the electrical protection device. This invention provides an operational status monitoring system for dual voltage transformers in a traction substation, comprising: a traction bus, two voltage transformers, and two circuit breakers; each voltage transformer includes a primary winding and a secondary winding; one end of each primary winding is electrically connected to the traction bus, and the other end of each primary winding is connected in series with a current transmitter before being grounded; the current signal acquired by the current transmitter is input to the input circuit of a PLC device; the PLC device is used to analyze the current signal and determine whether the voltage transformer is faulty; one end of the two secondary windings connected in parallel is connected to the voltage bus, and the other end of each secondary winding is grounded; the two circuit breakers are used to control the on / off state of the two secondary windings respectively.

[0005] The present invention involves setting one end of the primary winding of two voltage transformers electrically connected to the traction bus, and the other end of each transformer connected in series with a current transmitter before being grounded. When one voltage transformer fails, the current collected by the two current transmitters at the grounded ends of the two primary windings will show abnormal deviations or sudden changes. Since the current signals collected by the current transmitters are connected to the input circuit of a PLC device, the PLC device analyzes the current signals and determines whether the voltage transformer is faulty. This allows the abnormal current deviations or sudden changes caused by the voltage transformer failure to be observed or monitored, facilitating the repair of the faulty voltage transformer. This avoids the problem of both voltage transformers failing, leading to abnormal voltage readings or false or non-operational tripping of the power protection. The invention achieves monitoring of the operating status of dual voltage transformers, reduces the failure rate of traction substations, and improves the reliability of traction power supply.

[0006] Preferably, in the operation status monitoring system for the dual voltage transformers in the traction substation described in this utility model, each of the primary windings is equipped with a handcart at one end connected to the traction busbar; the position signal of the handcart is connected to the input circuit of the PLC device.

[0007] As a preferred embodiment of this utility model, a handcart is installed at one end of the primary winding connected to the traction busbar. The handcart is used to disconnect the circuit for maintenance of the voltage transformer, thus protecting the safety of maintenance personnel. When the handcart is disconnected, the voltage transformer is in a non-operating state. Even if there is an abnormal deviation or sudden change in the current collected by the current transmitter, this abnormality is caused by the change in the position of the handcart due to personnel maintenance, and no fault reminder for the operating status is given. This can meet the needs of personnel maintenance, correct the accuracy of voltage transformer operating status monitoring, further eliminate error monitoring data, enhance the use function of the system, and improve monitoring accuracy.

[0008] Preferably, in the traction substation dual voltage transformer operation status monitoring system of this utility model, the PLC device is equipped with an alarm signal; the alarm signal can issue alarm information and sound alarm when the voltage transformer fails.

[0009] As a preferred embodiment of this utility model, by setting an alarm and alarm signal in the PLC device, when the PLC device analyzes and determines that the voltage transformer has a fault, it will issue an alarm message and sound alarm, so that the monitoring personnel can be informed of the fault signal in time, which is conducive to timely reporting and maintenance, avoiding losses caused by untimely maintenance, and improving fault handling efficiency and production benefits.

[0010] Preferably, in the traction substation dual voltage transformer operation status monitoring system of this utility model, the PLC device further includes an interactive main interface; the interactive main interface is used by the operator to control the PLC device.

[0011] As a preferred embodiment of this utility model, by setting the interactive main interface, the monitoring personnel of the traction substation can be provided with the ability to monitor equipment safety, and the operation and parameter setting of the monitoring personnel are facilitated. This is conducive to the more automated and intelligent use of the system, and improves the efficiency and user experience.

[0012] Preferably, in the traction substation dual voltage transformer operation status monitoring system of this utility model, the PLC device further includes an online display main interface; the online display main interface is used to display the current deviation value between the two voltage transformers and the simulated image of the operation status of the two voltage transformers.

[0013] As a preferred embodiment of this utility model, the PLC device analyzes the current signal obtained by the current transmitter to calculate the current deviation value between the two voltage transformers, and then displays the current deviation value on the online display main interface, which can provide monitoring personnel with more intuitive current data. It can not only monitor whether the operating status of the dual voltage transformers is faulty, but also facilitate fault analysis and maintenance, further improving the system's performance and user experience.

[0014] Preferably, in the traction substation dual voltage transformer operation status monitoring system of this utility model, the PLC device is communicatively connected to the integrated automation system, thereby enabling the transmission of the current signal and alarm signal to the integrated automation system; the integrated automation system is used to transmit the current signal and alarm signal as monitoring data to the dispatching terminal and the local backend.

[0015] As a preferred embodiment of this utility model, the current signal acquired and processed by the PLC device is transmitted as monitoring data to the dispatching terminal and the local backend, enabling the local backend to obtain the operating status of the voltage transformer. This facilitates maintenance personnel to obtain fault information or view monitoring data in real time. On the other hand, the current signal and alarm signal are transmitted as monitoring data to the dispatching terminal, which allows for remote real-time monitoring of the operating status of the dual voltage transformers. This facilitates timely maintenance and troubleshooting, further enhancing the applicability of the system and improving the power supply reliability of the traction substation.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0017] By installing a current transmitter at the grounding terminal of the primary winding of each voltage transformer, the current of the two voltage transformers can be monitored. This allows for the observation or monitoring of abnormal current deviations or sudden current changes caused by faults in the voltage transformers. This enables the next step of repairing and maintaining the faulty voltage transformer, preventing both voltage transformers from failing and causing abnormal voltage readings or false tripping or failure of electrical protection devices. This achieves the monitoring of the operating status of dual voltage transformers, reduces the failure rate of traction substations, and improves the power supply reliability of traction substations. Attached Figure Description

[0018] Figure 1 This is a wiring diagram of this utility model;

[0019] Figure 2 This is a schematic diagram of the main interactive interface of this utility model;

[0020] Figure 3 This is a schematic diagram of the online display main interface of this utility model;

[0021] Icons: 1. Traction busbar; 2. Voltage transformer; 21. Primary winding; 22. Secondary winding; 3. Circuit breaker; 4. Current transmitter; 5. Voltage busbar; 6. Handcart; 7. Voltage interlock fuse. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0024] Example 1:

[0025] like Figure 1 As shown, this utility model discloses a monitoring system for the operation status of dual voltage transformers in a traction substation, comprising: a traction bus 1, two voltage transformers 2, and two circuit breakers 3; each of the two voltage transformers 2 includes a primary winding 21 and a secondary winding 22; one end of each of the two primary windings 21 is electrically connected to the traction bus 1, and the other end of each of the two primary windings 21 is connected in series with a current transmitter 4 and then grounded; the current signal collected by the current transmitter 4 is input to the input circuit of a PLC device; the PLC device is used to analyze the current signal and determine whether the voltage transformer 2 has a fault; one end of the two secondary windings 22 connected in parallel is connected to the voltage bus 55, and the other end of each of the two secondary windings is grounded; the two circuit breakers 3 are used to control the on / off state of the two secondary windings 22 respectively.

[0026] It should be noted that the dual voltage transformer is understood as a traction substation bus voltage acquisition mode with two voltage transformers 2, wherein the traction bus 1 is understood as the bus that provides power, such as the 27.5KV bus commonly used in traction substations.

[0027] The protection device described in this utility model refers to the integrated automation protection device of the traction substation. A fault in the voltage transformer 2 will cause an abnormality in the voltage collected by the protection device connected to the voltage bus 5, causing the related electrical protection of the protection device to malfunction or fail to operate.

[0028] The current transmitter 4 is understood as a component that can measure the current of the primary winding 21 circuit through circuit connection and convert the current value into a current signal to be transmitted to the PLC device. For example, a through-type current transmitter 4 is connected to the grounding line at the end of the primary winding 21. The current transmitters 4 set on the two primary windings 21 can respectively collect the current I1 and current I2 of the two voltage transformers 2 and input the current signal into the analog input circuit of the PLC device. The PLC device is understood as a device that can be programmed and cooperate with a microcomputer to realize automatic control and calculation.

[0029] Specifically, in this invention, a handcart 6 can be provided at one end of each primary winding 21 connected to the traction busbar 1; the position signal of the handcart 6 is connected to the input circuit of the PLC device; it should be noted that the handcart 6 is understood as the voltage transformer handcart 6, which, as an important electrical component of the power system, can take the voltage transformer out of operation for easy maintenance or replacement, ensuring the flexibility and reliability of the system. When the voltage transformer handcart 6 is out of operation, the voltage transformer 2 is in a non-operating state; in this embodiment, the acquisition of the position signal of the voltage transformer handcart 6 to determine the voltage transformer is in operation is a prerequisite for monitoring the operating status of the voltage transformer 2. The current change caused by the exit of the voltage transformer handcart 6, which provides a fault warning for the voltage transformer 2, is meaningless.

[0030] In this embodiment, specifically, each primary winding 21 is equipped with a voltage transformer fuse 7 at one end connected to the traction busbar 1. It should be noted that the voltage transformer fuse 7 is understood as a safety circuit for the voltage transformer 2. If an overvoltage or short circuit occurs, the safety circuit can disconnect, preventing damage to the circuit and equipment.

[0031] In this embodiment, specifically, the PLC device is equipped with an alarm signal; the alarm signal can issue alarm information and sound alarm when the voltage transformer fails; in conjunction with this, refer to Figure 2As shown, the PLC device also includes an interactive main interface; the interactive main interface is used by operators to control the PLC device; the interactive main interface of the PLC device is associated with the program set inside the PLC, and the data collected by the PLC device is displayed on the main interface in real time. When the PLC device is powered on, the system described in this utility model is in a monitoring state.

[0032] In this embodiment, specifically, the PLC device's communication interface is connected to the integrated automation system, enabling it to transmit the current signal and alarm information to the integrated automation system. The integrated automation system then transmits the current signal and alarm information as monitoring data to the local back-end dispatch terminal. In case of a fault, the PLC device's main interface will directly issue alarm information and sound, simultaneously uploading the alarm information to the integrated automation management unit, and then sending it to the dispatch terminal. For example, the PLC device communicates with the integrated automation system's management unit via an RS-485 communication interface, uploading the current signal and operating status data of the voltage transformer 2 to the local back-end and dispatch terminal, enabling the dispatch terminal to monitor the operating status of the dual voltage transformers 2 in real time.

[0033] The working principle of this utility model is as follows: When two voltage transformers 2 of the same phase have the same model and capacity, the current values ​​of the two voltage transformers 2 during operation are basically the same, and the current deviation is almost zero. When one of the voltage transformers 2 malfunctions, the current of that voltage transformer 2 will change suddenly. The current of the faulty voltage transformer 2 is less than the current of the normally operating voltage transformer 2, and the current difference between the two voltage transformers 2 is no longer zero, indicating that one of the voltage transformers 2 has malfunctioned. Specifically, the operating status of the dual voltage transformers is determined by the current change and the magnitude of the current difference. The set value of the voltage deviation is the threshold. If it is greater than the set value, the fault determination condition is met. The set value is set to the minimum current difference when one of the voltage transformers 2 malfunctions under no-load conditions. When the line is under load, the current difference between the two voltage transformers 2 is greater than the set value.

[0034] For details, please refer to Figure 3 As shown, the PLC device also includes an online display main interface; the online display main interface is used to display the current deviation value between the two voltage transformers 2 and the simulated image of the two voltage transformers 2.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A system for monitoring the operating status of dual voltage transformers in a traction substation, characterized in that, include: The system includes a traction bus (1), two voltage transformers (2), and two circuit breakers (3); each of the two voltage transformers (2) includes a primary winding (21) and a secondary winding (22); the first ends of the two primary windings (21) are electrically connected to the traction bus (1), and the tail ends of the two primary windings (21) are connected in series with a current transmitter (4) and then grounded; the current signal collected by the current transmitter (4) is connected to the input circuit of the PLC device; the PLC device is used to analyze the current signal and determine whether the voltage transformer (2) has a fault; one end of the two secondary windings (22) connected in parallel is connected to the voltage bus (5), and the other end of the two secondary windings (22) is grounded; the two circuit breakers (3) are used to control the on / off state of the two secondary windings (22).

2. The operating status monitoring system for dual voltage transformers in traction substations according to claim 1, characterized in that, Each of the primary windings (21) is connected to a handcart (6) at one end of the traction busbar (1); the position signal of the handcart (6) is connected to the input circuit of the PLC device.

3. The operating status monitoring system for dual voltage transformers in a traction substation according to claim 1, characterized in that, Each of the primary windings (21) is provided with a voltage interlocking fuse (7) at one end connected to the traction busbar (1).

4. The operating status monitoring system for dual voltage transformers in a traction substation according to claim 1, characterized in that, The PLC device is equipped with an alarm signal; the alarm signal can issue alarm information and sound alarm when the voltage transformer (2) fails.

5. The operating status monitoring system for dual voltage transformers in a traction substation according to claim 1, characterized in that, The PLC device also includes an interactive main interface; the interactive main interface is used by operators to control the PLC device.

6. The operating status monitoring system for dual voltage transformers in a traction substation according to claim 1, characterized in that, The PLC device also includes an online display main interface; the online display main interface is used to display the current deviation value between the two voltage transformers (2) and the simulated image of the two voltage transformers (2).

7. The operating status monitoring system for dual voltage transformers in a traction substation according to claim 1, characterized in that, The PLC device's communication interface is connected to the integrated automation system, thereby enabling the transmission of the current signal and alarm information to the integrated automation system; the integrated automation system is used to transmit the current signal and alarm information as monitoring data to the local back-end dispatch terminal.

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