Intelligent monitoring and switching device and method for traction substation voltage

Abstract

The application discloses a traction substation voltage intelligent monitoring switching device and method, relates to the technical field of railway traction power supply, and is characterized in that a main voltage transformer and a standby voltage transformer are arranged on each bus of a traction substation, a voltage transformer fault monitoring module is arranged for each voltage transformer, each voltage transformer fault monitoring module comprises a voltage discrimination circuit, a voltage once normal discrimination circuit, a no-voltage discrimination circuit, a voltage value low discrimination circuit, a voltage difference high discrimination circuit, a voltage transformer abnormality discrimination circuit and a voltage transformer normal discrimination circuit, and a voltage automatic switching device judges whether to switch the currently operated voltage transformer according to the voltage transformer abnormality signal or the voltage transformer normal signal output by each voltage transformer fault monitoring module. Whether the voltage transformer is abnormal is comprehensively judged according to the voltage transformer once normal sign, so that the voltage transformer fault used is determined, and the standby voltage transformer is automatically put into.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of railway traction power supply technology, in particular to a traction substation voltage intelligent monitoring switching device and method. BACKGROUND

[0002] In the railway traction power supply system, the traction network feeder protection and fault distance measuring device all need to collect bus voltage data, and the bus voltage is the basis for protection action and distance calculation during fault. In actual operation, most 27.5kV voltage transformers are equipped with high-voltage side fuses, and the fuses are mostly porcelain tube quartz sand plus fuse structure. After the fuse is blown, the breakage is very small, and there is still a high induced voltage. At this time, the voltage switching device can still collect the induced voltage, and the voltage switching device cannot automatically switch to the standby voltage transformer, affecting the safe operation of the entire traction power supply system. In the case of fuse failure, the voltage data collection is abnormal after the protection trips, the distance measurement error increases, and the judgment and emergency disposal during fault are affected. SUMMARY

[0003] The purpose of the present application is to provide a traction substation voltage intelligent monitoring switching device and method, which comprehensively judges whether the voltage transformer is abnormal according to the voltage transformer once normal sign, so as to determine whether the used voltage transformer is faulty or the high or low voltage fuse is blown, and automatically put into standby voltage transformer.

[0004] To achieve the above-mentioned purpose, the present application provides the following scheme:

[0005] On the one hand, the present application provides a traction substation voltage intelligent monitoring switching device, which comprises a voltage automatic switching device, and a main voltage transformer and a standby voltage transformer are arranged for each bus of the traction substation. A voltage transformer fault monitoring module is arranged for each voltage transformer, and each voltage transformer fault monitoring module comprises a voltage discrimination circuit, a voltage once normal discrimination circuit, a no voltage discrimination circuit, a voltage value low discrimination circuit, a voltage difference high discrimination circuit, a voltage transformer abnormality discrimination circuit and a voltage transformer normality discrimination circuit, wherein:

[0006] The voltage discrimination circuit triggers a voltage action signal;

[0007] The voltage once normal discrimination circuit triggers a voltage transformer once normal signal according to the voltage action signal;

[0008] The no voltage discrimination circuit triggers a no voltage action signal according to the voltage transformer once normal signal;

[0009] The voltage value low discrimination circuit triggers a voltage low signal according to the voltage transformer once normal signal;

[0010] The voltage difference high discrimination circuit triggers a voltage difference high signal according to the voltage transformer once normal signal;

[0011] The voltage transformer abnormality discrimination circuit triggers a voltage transformer abnormality signal according to the no-voltage action signal, the voltage low signal, and the voltage difference high signal;

[0012] The voltage transformer normality discrimination circuit triggers a voltage transformer normality signal according to the voltage action signal, the no-voltage action signal, the voltage low signal, and the voltage difference high signal;

[0013] The voltage automatic switching device judges whether to switch the currently running voltage transformer according to the voltage transformer abnormality signal or the voltage transformer normality signal output by the voltage transformer fault monitoring module.

[0014] In some embodiments, the voltage discrimination circuit includes a voltage comparator one comparing the input bus voltage fundamental component with the voltage setting value, an AND logic device one processing the output result of the voltage comparator one and the voltage soft panel input signal with AND logic, and an output voltage action signal after a set time limit of the output result of the AND logic device one.

[0015] In some embodiments, when the input bus voltage fundamental component is greater than or equal to the voltage setting value, the voltage action signal is output, and the voltage transformer normality flag is set and the voltage transformer normality signal is output when the voltage transformer normality discrimination circuit receives the voltage action signal.

[0016] When the input bus voltage fundamental component is lower than the voltage setting value, the voltage transformer normality flag is reset instantaneously by the voltage transformer normality discrimination circuit.

[0017] In some embodiments, the no-voltage discrimination circuit includes a voltage comparator two comparing the input voltage transformer voltage fundamental component with the no-voltage setting value, an AND logic device two processing the output result of the voltage comparator two, the voltage transformer normality signal, and the no-voltage action signal with AND logic, and an output no-voltage action signal after a set time limit of the no-voltage start signal.

[0018] In some embodiments, the voltage value low discrimination circuit includes a current comparator one comparing the absolute value of the difference between the T-line bus current and the F-line bus current of the main voltage transformer with the bus load current maximum value, a current comparator two comparing the absolute value of the difference between the T-line bus current and the F-line bus current of the standby voltage transformer with the bus load current maximum value, and an OR logic device one processing the output result of the current comparator one and the output result of the current comparator two with OR logic.

[0019] The voltage transformer voltage difference high soft pressure panel is triggered by the voltage transformer voltage difference high soft pressure panel input signal, and the voltage comparator four output result and the voltage comparator five output result are subjected to AND logic processing by the AND logic device four.

[0020] The voltage transformer voltage difference high soft pressure panel is triggered by the voltage transformer voltage difference high soft pressure panel input signal, and the voltage transformer voltage difference high soft pressure panel is triggered by the voltage transformer voltage difference high soft pressure panel input signal, and the voltage comparator four output result and the voltage comparator five output result are subjected to AND logic processing by the AND logic device four.

[0021] In some specific embodiments, the voltage difference high discrimination circuit includes a voltage transformer voltage difference high soft pressure panel triggered by a voltage transformer voltage difference high soft pressure panel input signal,

[0022] The voltage difference absolute value obtained by subtracting the T-line bus voltage of the standby voltage transformer from the T-line bus voltage of the main voltage transformer is compared with the set inherent error value by the voltage comparator four.

[0023] The ratio obtained by dividing the T-line bus voltage of the standby voltage transformer by the T-line bus voltage of the main voltage transformer is compared with the set voltage comparison coefficient by the voltage comparator five.

[0024] The voltage transformer voltage difference high soft pressure panel is triggered by the voltage transformer voltage difference high soft pressure panel input signal, and the voltage transformer voltage difference high soft pressure panel is triggered by the voltage transformer voltage difference high soft pressure panel input signal, and the voltage comparator four output result and the voltage comparator five output result are subjected to AND logic processing by the AND logic device four.

[0025] In some specific embodiments, the voltage transformer abnormality discrimination circuit includes an OR logic device two subjected to OR logic operation of the no-voltage action signal, the voltage low signal, and the voltage difference high signal, and the OR logic device two outputs a voltage transformer abnormality signal.

[0026] In some specific embodiments, the voltage transformer normality discrimination circuit includes a NOT logic device one subjected to NOT logic processing of the voltage low signal,

[0027] A NOT logic device two is subjected to NOT logic processing of the no-voltage action signal, a NOT logic device three is subjected to NOT logic processing of the voltage difference high signal, and an AND logic device five is subjected to AND logic processing of the NOT logic device one output, the NOT logic device two output, the NOT logic device three output, and the voltage action signal, and the AND logic device five outputs a voltage transformer normality signal.

[0028] In some specific embodiments, the voltage automatic switching device includes a T-line voltage transformer automatic switching hard pressure panel triggered by a T-line voltage transformer automatic switching hard pressure panel input signal, and a T-line bus voltage automatic switching soft pressure panel triggered by a T-line bus voltage automatic switching soft pressure panel input signal.

[0029] If the current running is the main voltage transformer, when receiving the T-line voltage mutual automatic switching hard pressure plate input signal, the T-line bus voltage automatic switching soft pressure plate input signal, the TF-line bus isolation is not in the split signal, the main voltage transformer abnormal signal and the standby voltage transformer normal signal, the voltage switching signal is output, and the standby voltage transformer is automatically switched.

[0030] In a second aspect, the application provides a traction substation voltage intelligent monitoring switching method, which specifically comprises the following steps:

[0031] S1, the bus voltage fundamental component of the current running voltage transformer and the standby voltage transformer is obtained respectively, and the running state of the two voltage transformers is monitored respectively, and the monitoring method is:

[0032] S11, when the bus voltage fundamental component is greater than the voltage value, the voltage normal flag of the voltage transformer is output, and when the bus voltage fundamental component is lower than the voltage value, the voltage normal flag of the current running voltage transformer is instantaneously reset;

[0033] S12, whether the voltage transformer is voltage action, the voltage value is low, and the voltage difference is high is judged according to the voltage normal flag of the voltage transformer;

[0034] S13, when the voltage transformer simultaneously satisfies voltage action, voltage value is low, and voltage difference is high, the voltage transformer is output, and when the voltage transformer simultaneously satisfies voltage action, voltage value is not low, voltage difference is not high and voltage is high, the voltage transformer is output;

[0035] S2, if the running state of the current running voltage transformer is voltage transformer abnormal and the running state of the standby voltage transformer is voltage transformer normal, the voltage automatic switching device switches the current running voltage transformer to the standby voltage transformer.

[0036] The application has the beneficial effects:

[0037] By analyzing the voltage curve and related fault waveform data of the 27.5kV bus voltage during the fuse failure of the traction substation, substation, AT substation and the like, combining the voltage switching rule, extracting the voltage change characteristics during the fuse failure, comparing the voltages, combining the voltage characteristics under the fuse failure state, designing the method of comparing the voltage waveform or difference change trend of the main and standby PTs, and then positioning the voltage transformer where the fuse failure occurs. The application does not need high-voltage power failure, does not need direct detection on the high-voltage side, the intelligent monitoring device cannot cause any influence on the original equipment and circuit when running, after determining that the voltage transformer used fails or the high-low voltage fuse is fused, the standby voltage transformer is automatically put into operation. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The schematic diagram of the logic circuit of the traction substation voltage intelligent monitoring switching device is provided for the embodiment of the present application.

[0039] Figure 2 The schematic diagram of the voltage transformer abnormality discrimination principle is provided for the embodiment of the present application.

[0040] Figure 3 The voltage discrimination principle diagram is provided for the embodiment of the present application.

[0041] Figure 4 The voltage discrimination principle diagram is provided for the embodiment of the present application.

[0042] Figure 5 The voltage value low discrimination principle diagram is provided for the embodiment of the present application.

[0043] Figure 6 The voltage difference high discrimination principle diagram is provided for the embodiment of the present application.

[0044] Figure 7 The voltage transformer abnormality discrimination principle is provided for the embodiment of the present application.

[0045] Figure 8 The voltage transformer normal discrimination principle is provided for the embodiment of the present application.

[0046] Figure 9 The voltage switching secondary principle diagram is provided for the embodiment of the present application.

[0047] Figure 10 The voltage automatic switching action logic is provided for the embodiment of the present application.

[0048] Figure 11 The voltage angle difference high discrimination is provided for the embodiment of the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present application will be described clearly and completely below with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0050] Unless specifically stated otherwise, the relative arrangement of components and steps, numerical expressions, and numerical values set forth in the embodiments are not intended to limit the scope of the present application.

[0051] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0052] Furthermore, for clarity and brevity, descriptions of well-known structures, functions, and configurations may have been omitted. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of this disclosure.

[0053] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0054] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0055] Example 1

[0056] like Figure 1 As shown, this embodiment provides a voltage intelligent monitoring and switching device for traction substations, including an automatic voltage switching device. Each bus section of the traction substation is equipped with a main voltage transformer and a backup voltage transformer. Each voltage transformer is equipped with a voltage transformer fault monitoring module. Each voltage transformer fault monitoring module includes a voltage presence detection circuit, a voltage normality detection circuit, a voltage absence detection circuit, a low voltage value detection circuit, a high voltage difference detection circuit, a voltage transformer abnormality detection circuit, and a voltage transformer normality detection circuit, wherein:

[0057] The voltage detection circuit triggers a voltage-activated signal;

[0058] Specifically, the voltage discrimination circuit includes a voltage comparator 1 that compares the fundamental component of the input bus voltage with the voltage setting value, an AND logic device 1 that performs AND logic processing on the output of the voltage comparator 1 and the voltage soft plate input signal, and an output voltage action signal after a set time limit on the output of the AND logic device 1.

[0059] The voltage normality detection circuit triggers the voltage transformer normality signal based on the voltage operation signal.

[0060] Specifically, when the fundamental component of the input bus voltage is greater than or equal to the voltage setting value, a voltage operation signal is output. When the voltage normality discrimination circuit receives the voltage operation signal, the voltage transformer normality flag is set and a voltage transformer normality signal is output.

[0061] When the fundamental component of the input bus voltage is lower than the no-voltage setting value, the voltage normality judgment circuit instantaneously resets the voltage transformer normality mark.

[0062] The no-voltage detection circuit triggers a no-voltage action signal based on the normal signal from the voltage transformer.

[0063] Specifically, the no-voltage detection circuit includes a voltage comparator two that compares the fundamental component of the input voltage transformer voltage with the no-voltage setting value; an AND logic device two that performs AND logic processing on the output of voltage comparator two, the voltage transformer previously normal signal, and the no-voltage non-operation signal; the AND logic device two outputs a no-voltage start signal; and after a set time limit, it outputs a no-voltage operation signal. The low voltage detection circuit triggers a low voltage signal based on the voltage transformer previously normal signal.

[0064] Specifically, the low voltage detection circuit includes a current comparator 1 that compares the absolute value of the difference between the T-line bus current and the F-line bus current of the input main voltage transformer with the maximum value of the bus load current; a current comparator 2 that compares the absolute value of the difference between the T-line bus current and the F-line bus current of the input standby voltage transformer with the maximum value of the bus load current; an OR logic device 1 that performs OR logic processing on the output results of current comparator 1 and current comparator 2; and a low voltage soft plate that triggers the low voltage soft plate input signal, and a voltage comparator 3 that compares the input bus voltage value with the minimum bus voltage value.

[0065] And the AND logic device three performs AND logic processing on the input signal of the low voltage value soft pressure plate of the voltage transformer, the normal signal of the voltage transformer, or the output result of logic device one and the output result of voltage comparator three, and outputs a low voltage signal after the output result of the AND logic device three has been processed for a set time limit.

[0066] The voltage difference high detection circuit triggers a voltage difference high signal based on the normal signal from the voltage transformer.

[0067] Specifically, the high voltage difference detection circuit includes a high voltage difference soft plate that triggers the input signal of the high voltage difference soft plate.

[0068] Voltage comparator four compares the absolute value of the voltage difference obtained by calculating the difference between the input T-line bus voltage of the main voltage transformer and the T-line bus voltage of the standby voltage transformer with the set inherent error value.

[0069] Voltage comparator five compares the ratio obtained by dividing the input standby voltage transformer's T-line bus voltage by the main voltage transformer's T-line bus voltage with the set voltage comparison coefficient.

[0070] and the voltage difference high signal is outputted after the time limit of the output result of the AND logic device four.

[0071] The voltage transformer abnormality discrimination circuit triggers the voltage transformer abnormality signal according to the no-voltage action signal, the voltage low signal and the voltage difference high signal.

[0072] Specifically, the voltage transformer abnormality discrimination circuit comprises an OR logic device two for performing OR logic operation on the no-voltage action signal, the voltage low signal and the voltage difference high signal, and the OR logic device two outputs the voltage transformer abnormality signal.

[0073] The voltage transformer normality discrimination circuit triggers the voltage transformer normality signal according to the voltage action signal, the no-voltage action signal, the voltage low signal and the voltage difference high signal.

[0074] Specifically, the voltage transformer normality discrimination circuit comprises a NOT logic device one for performing NOT logic operation on the voltage low signal, a NOT logic device two for performing NOT logic operation on the no-voltage action signal, a NOT logic device three for performing NOT logic operation on the voltage difference high signal, and an AND logic device five for performing AND logic operation on the output of the NOT logic device one, the output of the NOT logic device two, the output of the NOT logic device three and the voltage action signal, and the AND logic device five outputs the voltage transformer normality signal.

[0075] The voltage automatic switching device determines whether to switch the current running voltage transformer according to the voltage transformer abnormality signal or the voltage transformer normality signal outputted by each voltage transformer fault monitoring module.

[0076] The voltage automatic switching device comprises a T-line voltage transformer automatic switching hard pressure panel for triggering a T-line voltage transformer automatic switching hard pressure panel input signal and a T-line bus voltage automatic switching soft pressure panel for triggering a T-line bus voltage automatic switching soft pressure panel input signal.

[0077] If the current running voltage transformer is the main voltage transformer, when the T-line voltage transformer automatic switching hard pressure panel input signal, the T-line bus voltage automatic switching soft pressure panel input signal, the TF-line bus isolation not in the split signal, the main voltage transformer abnormality signal and the standby voltage transformer normality signal are received, the voltage switching signal is outputted, and the standby voltage transformer is automatically switched.

[0078] It can be understood that the railway traction substation (kiosk) 27.5kV each section of the bus is generally provided with 2 sets of 27.5kV voltage transformer, forming a main and standby redundant mode, the purpose is that when one voltage transformer fails, the device bus voltage can be switched to another voltage transformer for operation. The voltage analog quantity of the 27.5k bus voltage transformer is an important data indispensable for realizing the measurement and control of the traction substation. Once the data is interrupted or abnormal, it will cause the malfunction of the traction substation feeder system impedance protection, the main transformer system high voltage side and low voltage side low voltage starting overcurrent protection, fault distance measuring device, etc., interrupt the power supply of the catenary equipment, and cause serious deviation of the measurement data.

[0079] Currently, when the main and standby voltage transformers of the railway traction substation bus are switched, an abnormality occurs, causing the main low voltage starting overcurrent protection to malfunction, which seriously endangers the safe operation of traction power supply.

[0080] For example, in actual operation, most 27.5kV voltage transformers are equipped with high-voltage fuses, and the fuses are mostly porcelain tube quartz sand plus fuse structure. After the fuse is blown, the break is very small, and there is still a high induced voltage. The voltage switching device cannot automatically switch to the standby voltage transformer. Therefore, in the case of fuse failure, it will cause the protection to trip, the voltage data acquisition to be abnormal, the distance measurement error to increase, and the judgment and emergency disposal in the event of a fault to be affected.

[0081] Generally, the substation is an AT power supply mode, and 27.5kV bus is installed with a total of 4 voltage transformers, of which 1YH and 2YH are a group, serving as standby for each other, 3YH and 5YH are a group, serving as standby for each other, and 4YH and 6YH are a group, serving as standby for each other. Each voltage transformer contains T-line voltage transformer and F-line voltage transformer, a total of eight voltage transformers. When a voltage transformer fails, the device bus voltage can be switched to another normal voltage transformer for operation, improving the reliability of power supply. The 3YH, 4YH, 5YH, and 6YH voltage transformers have abnormality monitoring function and voltage transformer active fault detection function.

[0082] The following takes the main voltage transformer UT1-1 as an example to illustrate the abnormality monitoring of the voltage transformer by the device, as shown in Figure 2 , which is a schematic diagram of the overall discrimination principle. The monitoring method of other voltage transformers is the same. The following describes each module:

[0083] 1.1, voltage discrimination

[0084] The voltage discrimination principle is shown in Figure 3 . UT1-1 is the bus voltage fundamental component, Uset is the voltage setting value, and Tset is the time limit setting value. When the bus voltage fundamental component is greater than or equal to the voltage setting value, UT1-1 is output with voltage. The device is configured with 8 voltage discrimination elements respectively, and shares a group of voltage setting values.

[0085] 1.2, Voltage once normal flag

[0086] Take UT1-1 as an example, when it is judged that UT1-1 has voltage action, the voltage once normal flag of UT1-1 is set, and when the voltage value of UT1-1 is lower than the no-voltage setting value, the voltage once normal flag of UT1-1 is reset momentarily.

[0087] 1.3, No-voltage discrimination

[0088] The no-voltage discrimination principle is shown in Figure 4 . UT1-1 is the voltage fundamental component of the voltage transformer, Uset is the no-voltage setting value, and Tset is the no-voltage time limit setting value. When the voltage fundamental component of the voltage transformer has voltage and no-voltage is not in action and the voltage fundamental component of the voltage transformer is less than or equal to the no-voltage setting value, the no-voltage start is output, and the no-voltage action is output after the no-voltage time limit. The device is configured with 8 voltage paths, each of which is separately configured with a no-voltage discrimination element, and shares a set of no-voltage setting values.

[0089] 1.4, Voltage value is low

[0090] The voltage value low discrimination principle is shown in Figure 5 . Um.min is the minimum bus voltage value, and Im.min is the maximum bus load current value. When the voltage once normal of UT1-1, UT1-1 < the minimum bus voltage value, and the difference between the bus current of the main voltage transformer and the bus current of the standby voltage transformer is less than the maximum bus load current value, the voltage value of UT1-1 is output.

[0091] 1.5, Voltage difference is high

[0092] Take UT1-1 as an example for description, and the other voltage transformers are similar. The voltage difference high discrimination principle is shown in Figure 6 . K is the voltage comparison coefficient, which can be set, and the default value is 1.01. When the voltage once normal of UT1-1, the bus voltage difference between the main voltage transformer and the standby voltage transformer is greater than the inherent error value of the measured value of the two voltage transformers, and the bus voltage ratio of the main voltage transformer and the standby voltage transformer is greater than the voltage comparison coefficient, the voltage difference of UT1-1 is output. To better compare the voltages of UT1-1 and UT1-2, when UT1-2 is normally operated near the rated voltage, and the voltage of U1-1 is within the range of 95% to 105% of UT1-2, the voltage of UT1-2 can be used as a reference to calibrate the fine tuning coefficient of UT1-1 to offset the system error and keep the measured voltages of the two voltage transformers consistent when they are normally operated.

[0093] 1.6, Voltage transformer abnormality judgment logic

[0094] Take UT1-1 as an example to illustrate the abnormal judgment logic of voltage transformer, and the abnormal judgment logic of other seven voltage transformers is similar. The abnormal judgment principle of voltage transformer is shown in Figure 7 , when UT1-1 has no voltage action or UT1-1 voltage is low or UT1-1 voltage difference is high, it is judged that the main voltage transformer is abnormal. If the voltage transformer is determined to be abnormal, a fault report is generated, and the sampling data of the previous two cycles and the next eight cycles before the abnormality is uploaded as the fault waveform.

[0095] 1.7, voltage transformer normal judgment logic

[0096] Take UT1-1 as an example to illustrate the normal judgment logic of voltage transformer, and the abnormal judgment logic of other seven voltage transformers is similar. The normal judgment principle of voltage transformer is shown in Figure 8 , when UT1-1 has no voltage action and UT1-1 voltage is low and or UT1-1 voltage difference is high, it is judged that the main voltage transformer is normal.

[0097] 2, voltage switching device

[0098] Three kinds of redundant voltage switching operations are set in the system, including voltage automatic switching, voltage remote control switching and voltage manual switching, and each group of main and backup voltage transformers has three switching modes to choose from, including manual switching, automatic switching and remote control switching. Remote switching includes dispatching end active switching, background machine operator switching and response switching. Response switching is a man-machine dialogue function, when the operation voltage transformer monitoring is abnormal, the comprehensive automation background machine pops up an alarm information, and the operator determines whether to switch the voltage according to the situation. The voltage automatic switching function of the voltage transformer monitoring switching device can switch from the main voltage transformer to the backup voltage transformer, or from the backup voltage transformer to the main voltage transformer. The device must confirm that the voltage of the other (group) voltage transformer is normal before switching.

[0099] The secondary principle diagram of voltage switching is shown in Figure 9 , T1, T2, F1, F2 bus voltage automatic switching is independent of each other. Take T1 bus as an example, terminals (D1, D2) and (D3, D4) are two pairs of contacts of the same relay, (D1, D2) is normally closed contact, (D3, D4) is normally open contact. In principle, the main voltage transformer voltage is connected to terminal (D1, D2), and the backup voltage transformer voltage is connected to terminal (D3, D4). Other bus voltages are connected according to the same principle. Assuming that the initial state is UT1-1 main and UT1-2 backup, that is, (D1, D2) is closed and (D3, D4) is opened, the following describes the three modes in turn:

[0100] 2.1 voltage automatic switching

[0101] Assuming the initial state is UT1-1 master, UT1-2 backup, that is, (D1, D2) is closed, (D3, D4) is open, and the voltage automatic switching action logic is as shown in the figure. In the figure, "T1 voltage mutual automatic switching hard panel" is the device hardware input. "T1 bus voltage automatic switching soft panel" is the user-defined soft panel. The voltage switching signal outlet drives the signal plug-in relay, the terminal (D1, D2) node is open, and the terminal (D3, D4) node is closed. Figure 10

[0102] The device automatically identifies the switching action result, reports "voltage automatic switching success" event after successful switching, and reports "voltage automatic switching loop abnormality" if the switching fails, and reports the self-check report "voltage switching relay is bad" at the same time, and the alarm light is on. Lock the bus voltage automatic switching action, and the device can restore the function after troubleshooting and returning to normal.

[0103] After the first automatic switching success action, it must pass through 20s automatic return time to start the next action, or use the panel return key to return within 20s.

[0104] 2.2, voltage remote switching

[0105] Taking T1 bus as an example, the voltage remote switching function opening condition is that "T1 voltage mutual automatic switching hard panel" is put in and "T1 bus voltage automatic switching soft panel" is withdrawn. The remote control should be configured as a unit direct control mode.

[0106] 2.3, voltage manual switching

[0107] When the remote control cannot be completed due to communication failure, the device supports manual switching. Taking T1 bus as an example, the manual switching function opening condition is that "T1 voltage mutual automatic switching hard panel" is withdrawn. Trigger power input B017, terminal (D1, D2) node is closed, and terminal (D3, D4) node is open; trigger power input B017, terminal (D1, D2) node is open, and terminal (D3, D4) node is closed.

[0108] The device also provides a high-angle difference alarm for bus voltage transformer. When it is monitored that the voltage angle difference between two voltage transformers on the same bus is greater than the threshold Φ, an alarm signal is sent. The event report is generated and saved. Taking UT1-1 bus as an example for description, the voltage angle difference criterion of other bus voltage transformers is similar. For example, Figure 11 ​As shown, the voltage angle difference high discrimination logic is: when the voltage angle difference of two voltage transformers on the same bus is greater than the threshold value Φ and both are greater than the setting value USY, it is judged that the voltage angle difference of the voltage transformer is high. In order to better compare the voltage angles of UT1-1 and UT1-2, when UT1-1 and UT1-2 are normally operated near the rated voltage, the voltage angle of UT1-2 can be used as a reference to fine-tune the angle of UT1-1 to offset the system error and keep the voltage angle difference of the two voltage transformers close to zero when they are normally operated.

[0109] The device also provides an active fault detection function of the transformer, which can detect the fault of the eight voltage transformer branches through the detection circuit. The fault detection process of each circuit is similar. Taking the circuit of UT1-1 as an example, the process of fault detection is described below. After receiving the remote control detection command of the voltage transformer in the circuit of UT1-1, the device records the voltage amplitude of UT1-1, sends the voltage transformer detection on-off command in the circuit of UT1-1, delays for t (which can be set, the default value is 30 ms), then records the voltage amplitude of UT1-1 at this time, and then withdraws the voltage transformer detection on-off command. Calculate the voltage difference before and after the circuit is turned on. If the difference is greater than the set value, it is judged that the voltage transformer is faulty, a fault report is generated, and the sampling data of the previous two cycles before remote control and the next eight cycles after remote control are uploaded as fault waveforms.

[0110] Embodiment 2

[0111] The embodiment provides a traction substation voltage intelligent monitoring switching method, which is applied to the device in embodiment 1, and comprises the following steps:

[0112] S1, the bus voltage fundamental component of the currently operating voltage transformer and the standby voltage transformer is obtained respectively, and the operating state of the two voltage transformers is monitored respectively, and the monitoring method is:

[0113] S11, when the bus voltage fundamental component is greater than the voltage value, the voltage value is output and the voltage value is normal, and when the bus voltage fundamental component is less than the voltage value, the voltage value is normal, the voltage value is normal, and the voltage value is normal.

[0114] S12, whether the voltage transformer is voltage action, the voltage value is low, and the voltage difference is high is judged according to the voltage value of the voltage transformer;

[0115] S13, when the voltage transformer simultaneously satisfies the voltage action, the voltage value is low, and the voltage difference is high, the voltage transformer is abnormal, and when the voltage transformer simultaneously satisfies the voltage action, the voltage value is not low, the voltage difference is not high, and the voltage value is normal, the voltage transformer is normal.

[0116] S2, if the running state of the currently running voltage transformer is voltage transformer abnormal and the running state of the standby voltage transformer is voltage transformer normal, the voltage automatic switching device switches the currently running voltage transformer to the standby voltage transformer.

[0117] It can be understood that, in order to ensure the safe and stable operation of the traction power supply system, the 27.5kV voltage intelligent monitoring device proposed in the application does not need to be powered off on the high-voltage side and does not need to be directly detected on the high-voltage side. When the intelligent monitoring device is running, it will not cause any impact on the original equipment and circuit. When it is judged that the high-voltage fuse has been blown, the result can be directly displayed and judged. When the high-voltage fuse is not blown, the real-time measured voltage data can be directly displayed, and an alarm sound is issued to prompt that the voltage at this time is the normal operating voltage. After it is determined that the voltage transformer used is faulty or the high-low voltage fuse is blown, the standby voltage transformer is automatically put into operation, the 27.5kV voltage intelligent monitoring device is integrated into the comprehensive automation system, and the switching information of the voltage transformer is transmitted to the dispatching terminal through the remote system, meeting the requirement of unattended traction substation. The 27.5kV voltage intelligent monitoring switching device for railway traction substation proposed in the application can be based on the PAC (programmable automatic controller) software and hardware platform, the software development adopts the "VLD" visual logic development tool, the device has an offline logic simulation function, and the "transparency" of accident analysis is realized.

[0118] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. According to the technical essence of the present application, any simple modification, equivalent replacement and improvement of the above embodiment within the spirit and principles of the present application are still within the protection scope of the technical scheme of the present application.

Claims

1. A voltage intelligent monitoring and switching device for traction substations, characterized in that, This includes automatic voltage switching devices. Each bus section of the traction substation is equipped with a main voltage transformer and a backup voltage transformer. Each voltage transformer has a separate voltage transformer fault monitoring module. Each voltage transformer fault monitoring module includes a voltage presence detection circuit, a voltage normality detection circuit, a voltage absence detection circuit, a low voltage value detection circuit, a high voltage difference detection circuit, a voltage transformer abnormality detection circuit, and a voltage transformer normality detection circuit. Among these: The voltage detection circuit triggers a voltage-activated signal; The voltage normality detection circuit triggers the voltage transformer normality signal based on the voltage operation signal. The no-voltage detection circuit triggers a no-voltage action signal based on the normal signal from the voltage transformer. The low voltage detection circuit triggers a low voltage signal based on the normal voltage transformer signal. The voltage difference high detection circuit triggers a voltage difference high signal based on the normal signal from the voltage transformer. The voltage transformer fault detection circuit triggers voltage transformer fault signals based on no-voltage action signals, low voltage signals, and high voltage difference signals. The voltage transformer normal operation detection circuit triggers the voltage transformer normal operation signal based on the voltage on operation signal, voltage off operation signal, low voltage signal, and high voltage difference signal. The automatic voltage switching device determines whether to switch the currently operating voltage transformer based on the abnormal or normal voltage transformer signals output by the fault monitoring module of each voltage transformer.

2. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The voltage discrimination circuit includes a voltage comparator 1 that compares the fundamental component of the input bus voltage with the voltage setting value, an AND logic device 1 that performs AND logic processing on the output of the voltage comparator 1 and the voltage soft plate input signal, and an output voltage action signal after a set time limit on the output of the AND logic device 1.

3. The intelligent voltage monitoring and switching device for traction substations according to claim 2, characterized in that, When the fundamental component of the input bus voltage is greater than or equal to the voltage setting value, a voltage operation signal is output. When the voltage normality discrimination circuit receives the voltage operation signal, the voltage transformer normality flag is set and a voltage transformer normality signal is output. When the fundamental component of the input bus voltage is lower than the no-voltage setting value, the voltage normality judgment circuit instantaneously resets the voltage transformer normality mark.

4. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The no-voltage discrimination circuit includes a voltage comparator two that compares the fundamental component of the input voltage transformer voltage with the no-voltage setting value, an AND logic device two that performs AND logic processing on the output of the voltage comparator two, the voltage transformer normal signal, and the no-voltage non-operation signal, the AND logic device two outputs a no-voltage start signal, and after the no-voltage start signal passes through a set time limit, outputs a no-voltage operation signal.

5. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The low voltage detection circuit includes a current comparator 1 that compares the absolute value of the difference between the T-line bus current and the F-line bus current of the input main voltage transformer with the maximum value of the bus load current, and a current comparator 2 that compares the absolute value of the difference between the T-line bus current and the F-line bus current of the input standby voltage transformer with the maximum value of the bus load current, and an OR logic device 1 that performs OR logic processing on the output results of current comparator 1 and current comparator 2. It also includes a low voltage soft switch that triggers the low voltage soft switch signal, and a voltage comparator three that compares the input bus voltage value with the minimum bus voltage value. And the AND logic device three performs AND logic processing on the input signal of the low voltage value soft pressure plate of the voltage transformer, the normal signal of the voltage transformer, or the output result of logic device one and the output result of voltage comparator three, and outputs a low voltage signal after the output result of the AND logic device three has been processed for a set time limit.

6. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The high voltage difference detection circuit includes a high voltage difference soft plate that triggers the input signal of the high voltage difference soft plate; Voltage comparator four compares the absolute value of the voltage difference obtained by calculating the difference between the input T-line bus voltage of the main voltage transformer and the T-line bus voltage of the standby voltage transformer with the set inherent error value. Voltage comparator five compares the ratio obtained by dividing the input standby voltage transformer's T-line bus voltage by the main voltage transformer's T-line bus voltage with the set voltage comparison coefficient. And AND logic device four, which performs AND logic processing on the input signal of the soft pressure plate with high voltage difference between the voltage transformers, the normal signal of the voltage transformer, the output result of voltage comparator four, and the output result of voltage comparator five, outputs a high voltage difference signal after the output result of AND logic device four has been processed for a set time limit.

7. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The voltage transformer fault detection circuit includes an OR logic device two that performs an OR logic operation on the no-voltage action signal, the low voltage signal, and the high voltage difference signal, and outputs a voltage transformer fault signal from the OR logic device two.

8. The intelligent voltage monitoring and switching device for traction substations according to claim 1, characterized in that, The voltage transformer normal operation detection circuit includes a non-logic device that performs non-logic processing on the low voltage signal. Non-logic device two performs non-logic processing on the no-pressure action signal, non-logic device three performs non-logic processing on the high voltage difference signal, AND logic device five performs AND logic processing on the outputs of non-logic device one, non-logic device two, non-logic device three, and the pressure action signal, and AND logic device five outputs the normal signal of the voltage transformer.

9. A traction substation voltage intelligent monitoring and switching device according to claim 4, characterized in that, The automatic voltage switching device includes a T-line voltage switching hard plate that triggers the signal to activate the T-line voltage switching hard plate, and a T-line bus voltage switching soft plate that triggers the signal to activate the T-line bus voltage switching soft plate. If the primary voltage transformer is currently in operation, when it receives the following signals: automatic switching hard plate activation signal for T-line voltage transformer, automatic switching soft plate activation signal for T-line bus voltage transformer, signal indicating that the TF-line bus is not in the isolation position, or an abnormal signal from the primary voltage transformer and a normal signal from the standby voltage transformer, it will output a voltage switching signal and automatically switch to the standby voltage transformer.

10. A method for intelligent monitoring and switching of voltage in a traction substation, characterized in that, Specifically, the following steps are included: S1. Obtain the fundamental bus voltage components of the currently operating voltage transformer and the standby voltage transformer respectively, and monitor the operating status of the two voltage transformers respectively. The monitoring method is as follows: S11. When the fundamental component of the bus voltage is greater than the voltage setting value, output a voltage-activated signal and set the voltage normality flag of the voltage transformer. When the fundamental component of the bus voltage is lower than the voltage-free setting value, instantaneously reset the voltage normality flag of the currently operating voltage transformer. S12. Based on the voltage normal marking of the voltage transformer, determine whether the voltage transformer is operating without voltage, whether the voltage value is too low, and whether the voltage difference is too high. S13. When the voltage transformer simultaneously meets the conditions of no-voltage operation, low voltage value, and high voltage difference, the output voltage transformer is abnormal. When the voltage transformer simultaneously meets the conditions of no-voltage operation, no low voltage value, no high voltage difference, and voltage operation, the output voltage transformer is normal. S2. If the operating status of the currently operating voltage transformer is abnormal and the operating status of the standby voltage transformer is normal, the automatic voltage switching device will switch the currently operating voltage transformer to the standby voltage transformer.

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