Method and system for detecting open delta winding loop of voltage transformer

Abstract

The invention provides a detection method and system for an open delta winding loop of a voltage transformer, and the method comprises the steps: connecting a detection device in parallel between the open delta winding loop of the voltage transformer and a secondary load resistor, the detection device outputting an adjustable direct current, and the amplitude of the adjustable direct current being smaller than or equal to a preset low current threshold; gradually increasing the direct current value output by the detection device within the range of the low current threshold value, and continuously detecting voltages at two ends of the open delta winding of the voltage transformer under different direct current values through the detection device; respectively comparing the voltages at the two ends of the open delta winding under different direct current values with the corresponding detection values, and judging the state of the open delta winding loop of the voltage transformer according to the comparison result. According to the method, the detection device is arranged to output low direct current and carry out voltage detection, so that the state of the open delta winding loop of the voltage transformer in operation can be accurately and effectively detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage transformer state detection, and in particular to a detection method and system for an open delta winding loop of a voltage transformer. BACKGROUND

[0002] At present, voltage transformers have been widely used in various fields such as power systems. The function of the voltage transformer is to convert high voltage into low voltage for use by measuring, protecting and monitoring devices. The open delta winding loop (which can be referred to as an open delta voltage loop) formed by the residual secondary windings of a three-phase voltage transformer has the function of measuring the zero sequence voltage of the system.

[0003] Among them, since the open delta voltage loop of the three-phase voltage transformer is an open delta formed by the residual windings of the A, B and C phase voltage transformers according to a certain polarity, the voltage of the open delta voltage loop of the voltage transformer is zero under normal operation of the power system, and it is impossible to judge whether the open delta voltage loop is normal through voltage measurement on the basis of the original. And according to the relevant provisions of the power system, fuses cannot be installed in the open delta voltage loop, because if the fuse is blown during normal operation of the power system, it cannot be detected through the measurement table.

[0004] Since there is no voltage in the open delta voltage loop when the system is normal, when the open delta voltage loop appears short circuit or open circuit, it still shows that there is no voltage in the open delta voltage loop, causing detection difficulty. Therefore, there is a lack of effective detection scheme for the state of the open delta winding loop of the voltage transformer in the related art. SUMMARY

[0005] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0006] To this end, a first object of the present application is to provide a detection method for an open delta winding loop of a voltage transformer. The method can accurately and effectively detect the state of the open delta winding loop of the voltage transformer in operation by setting a detection device to output a low direct current and performing voltage detection.

[0007] A second object of the present application is to provide a detection system for an open delta winding loop of a voltage transformer.

[0008] A third object of the present application is to provide an electronic device.

[0009] A fourth object of the present application is to provide a computer readable storage medium.

[0010] To achieve the above objects, a first aspect of the present application provides a detection method for an open delta winding loop of a voltage transformer, comprising the following steps:

[0011] The detection device is connected in parallel between the open delta winding loop of the voltage transformer and the secondary load resistor, wherein the detection device outputs an adjustable DC current, and the adjustable DC current has an amplitude less than or equal to a preset low current threshold value;

[0012] The DC current value output by the detection device is gradually increased within the range of the low current threshold value, and the voltage across the open delta winding of the voltage transformer under different DC current values is continuously detected by the detection device.

[0013] The voltages across the open delta winding under different DC current values are compared with corresponding detection values respectively, and the state of the open delta winding loop of the voltage transformer is determined according to the comparison results, wherein the state includes a normal state, an open circuit state and a short circuit state.

[0014] Optionally, the determination of the state of the open delta winding loop of the voltage transformer according to the comparison results includes: in response to the DC current value output by the detection device being constant at the low current threshold value, calculating a first detection value in the normal state according to the DC resistance value of the open delta winding loop of the voltage transformer, the resistance value of the secondary load resistor and the low current threshold value; comparing the two-terminal voltage currently detected by the detection device with the first detection value, and determining that the open delta winding loop of the voltage transformer is in the normal state when the two-terminal voltage matches the first detection value.

[0015] Optionally, after the response to the DC current value output by the detection device being constant at the low current threshold value, the method further includes: calculating a second detection value in the short circuit state according to the resistance value of the load side in the short circuit state and the low current threshold value; comparing the two-terminal voltage currently detected by the detection device with the second detection value, and determining that the open delta winding loop of the voltage transformer is in the short circuit state when the two-terminal voltage matches the second detection value.

[0016] Optionally, the determination of the state of the open delta winding loop of the voltage transformer according to the comparison results includes: comparing the two-terminal voltage under any DC current value with a preset open circuit fault detection value during the gradual increase of the DC current value output by the detection device; and determining that the open delta winding loop of the voltage transformer is in the open circuit state when the two-terminal voltage reaches the open circuit fault detection value.

[0017] Optionally, after judging the state of the open-delta winding circuit of the voltage transformer according to the comparison result, the method further comprises: in response to the state of the open-delta winding circuit of the voltage transformer being the open-circuit state or the short-circuit state, sending fault alarm information to a worker by the detection device.

[0018] Optionally, the open-circuit fault detection value is determined based on a resistance value of the secondary load resistor, and the low current threshold is 50 mA.

[0019] To achieve the above purpose, the second aspect of the present application further proposes a detection system of an open-delta winding circuit of a voltage transformer, comprising the following modules:

[0020] A setting module is configured to connect a detection device in parallel between the open-delta winding circuit of the voltage transformer and the secondary load resistor, wherein the detection device outputs an adjustable direct current, and an amplitude of the adjustable direct current is less than or equal to a preset low current threshold;

[0021] A detection module is configured to gradually increase a direct current value output by the detection device within a range of the low current threshold, and continuously detect voltages at both ends of the open-delta winding of the voltage transformer under different direct current values by the detection device.

[0022] A judgment module is configured to compare the voltages at both ends of the open-delta winding under different direct current values with corresponding detection values respectively, and judge a state of the open-delta winding circuit of the voltage transformer according to a comparison result, wherein the state comprises a normal state, an open-circuit state and a short-circuit state.

[0023] To achieve the above purpose, the third aspect of the present application further proposes an electronic device, comprising: at least one processor; and a memory communicatively connected with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the detection method of the open-delta winding circuit of the voltage transformer according to any one of the above first aspect.

[0024] To achieve the above purpose, the fourth aspect of the present application further proposes a non-transitory computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the detection method of the open-delta winding circuit of the voltage transformer according to any one of the above first aspect.

[0025] The technical scheme provided by the embodiment of the application brings at least the following beneficial effects: the application can accurately and effectively detect the open circuit and short circuit of the open delta winding circuit of the voltage transformer in operation by connecting the detection device in parallel between the open delta winding circuit of the voltage transformer and the secondary load resistor, outputting low direct current from the detection device and detecting voltage, and timely reminding relevant personnel to eliminate the abnormality when the open delta winding circuit is in an abnormal state, which can prevent the relay protection device from refusing to act or causing the voltage transformer to burn out when the system accident occurs. Moreover, the detection device is set as a constant current source and adopts the mode of outputting low direct current, which can effectively prevent the voltage transformer secondary side from being charged to the primary side, and avoid the adverse effects of the detection device on the voltage transformer. The detection data obtained by the application has high distinguishability for judging the state of the open delta winding circuit of the voltage transformer, and can timely and accurately judge the normal state, open circuit state or short circuit state of the open delta winding circuit. Therefore, the application is beneficial to ensuring the safe and stable operation of the voltage transformer and the power system.

[0026] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0027] The above and / or additional aspects and advantages of the application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0028] Figure 1 A flow chart of a detection method of an open delta winding circuit of a voltage transformer according to an embodiment of the application is shown in the figure;

[0029] Figure 2 A schematic diagram of an open delta winding circuit of a voltage transformer in a normal state according to an embodiment of the application is shown in the figure;

[0030] Figure 3 A schematic diagram of an open delta winding circuit of a voltage transformer in a short circuit state according to an embodiment of the application is shown in the figure;

[0031] Figure 4 A schematic diagram of an open delta winding circuit of a voltage transformer in an open circuit state according to an embodiment of the application is shown in the figure;

[0032] Figure 5 A structural schematic diagram of a detection system of an open delta winding circuit of a voltage transformer according to an embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations throughout the attached drawing figures. The embodiments described below are exemplary in nature, and are intended to be illustrative of the present application rather than to limit the same.

[0034] It should be noted that when the power system has an asymmetric fault, if a single-phase grounding short circuit occurs, a zero sequence voltage will appear in the open delta winding circuit of the three-phase voltage transformer, and the zero sequence protection or ground fault detection will be performed by the related protection device or measurement device. Therefore, the open delta winding circuit of the three-phase voltage transformer needs to ensure the reliability of operation. According to the working principle of the voltage transformer, the secondary side is strictly prohibited from short circuiting. If a short circuit occurs at the secondary side of the voltage transformer, for the open delta winding circuit, when the system is normally operated, no impact will be caused to the voltage transformer due to the zero voltage. However, if a single-phase grounding fault occurs in the system, the short circuit of the zero sequence voltage of the open delta winding circuit will generate a great short circuit current, which is extremely easy to cause the secondary winding of the voltage transformer to burn out, thereby causing a serious impact on the safe operation of the power system. However, the related embodiments cannot effectively detect the state of the open delta winding circuit of the voltage transformer.

[0035] Therefore, the present application provides a detection method and system for the open delta winding circuit of a voltage transformer, which can accurately and effectively detect the state of the open delta winding circuit of the voltage transformer in operation.

[0036] Hereinafter, a detection method and system for the open delta winding circuit of a voltage transformer according to an embodiment of the present application are described with reference to the accompanying drawings.

[0037] Figure 1 A flowchart of the detection method for the open delta winding circuit of a voltage transformer according to an embodiment of the present application is shown in FIG. 1, which includes the following steps: Figure 1

[0038] In step S101, a detection device is connected in parallel between the open delta winding circuit of the voltage transformer and the secondary load resistor, wherein the detection device outputs an adjustable direct current, and the amplitude of the adjustable direct current is less than or equal to a preset low current threshold.

[0039] Specifically, since the voltage transformer is applied to an alternating current electrical system, the transformation thereof is an alternating current electrical quantity. By utilizing this characteristic of the voltage transformer, the detection device for the open delta winding circuit of the voltage transformer according to the present application adopts a direct current signal source to solve the problem of back charging of the voltage transformer (i.e., the low voltage at the secondary side is transformed to a high voltage at the primary side), thereby avoiding the adverse impact of the detection device on the normal operation of the voltage transformer.

[0040] ​In order to ensure the safety of the open-delta winding loop state detection, the detection device is connected in parallel between the open-delta winding loop of the voltage transformer and the secondary load resistor. The detection device can output a direct current with an adjustable current value, and has a constant current characteristic, that is, after adjusting the detection device to output a certain current value, the detection device can constantly output the direct current value until the next adjustment. In addition, the amplitude of the direct current output by the detection device is controlled within a preset low current threshold range, that is, less than or equal to the low current threshold. For example, the low current threshold can be 50 mA. Therefore, the detection device of the application uses a constant current source and outputs a lower direct current, which can effectively avoid the back charging of the primary side from the secondary side of the voltage transformer.

[0041] In step S102, the direct current value output by the detection device is gradually increased within the range of the low current threshold, and the voltage across the open-delta winding of the voltage transformer under different direct current values is continuously detected by the detection device.

[0042] Specifically, the detection device provided by the application is equipped with a current output port that can output a direct current for detection. According to the control instruction, the detection device can output direct currents with various current values within the range defined by the low current threshold. For example, after starting the detection, the detection device can start from 0 mA and continuously increase the output direct current value until it reaches 50 mA.

[0043] Further, under the condition that the detection device outputs a direct current, the approximate voltage value across the open-delta winding under various states of the open-delta winding loop of the voltage transformer can be calculated as a detection value based on the circuit structure of the open-delta winding of the voltage transformer, the resistance values of the components, and the current value of the currently output direct current, according to Ohm's law.

[0044] In addition, the detection device also has a voltage detection function, which can detect the actual voltage value across the open-delta winding of the voltage transformer under different direct current values, so as to determine the detection result subsequently.

[0045] In step S103, the voltage across the open-delta winding under different direct current values is compared with the corresponding detection value, and the state of the open-delta winding loop of the voltage transformer is determined according to the comparison result, wherein the state includes a normal state, an open-circuit state and a short-circuit state.

[0046] Specifically, since the voltage transformer is equivalent to a voltage source with a very small internal resistance, the secondary circuit of the voltage transformer is strictly prohibited from being short-circuited, and therefore the load connected to the open-delta winding circuit of the voltage transformer is usually high resistance. According to the above steps, the detection value corresponding to each state of the open-delta winding circuit of the voltage transformer can be calculated based on the circuit structure of the open-delta winding circuit of the voltage transformer after the parallel detection device, the resistance values of the components including the load, and the current value of the output DC current. Then, the actual voltage across the open-delta winding detected at the current output DC current value is compared with the corresponding detection value, and the state of the open-delta winding circuit of the voltage transformer is determined according to the comparison result.

[0047] The specific detection and determination process will be described in detail below with several specific examples.

[0048] In an embodiment of the present application, the state of the open-delta winding circuit of the voltage transformer is determined according to the comparison result, including: in response to the DC current value output by the detection device being constant at a low current threshold, calculating a first detection value in the normal state according to the DC resistance value of the open-delta winding circuit of the voltage transformer, the resistance value of the secondary load resistance, and the low current threshold; comparing the voltage across the open-delta winding currently detected by the detection device with the first detection value, and determining that the open-delta winding circuit of the voltage transformer is in the normal state when the voltage across the open-delta winding matches the first detection value.

[0049] Specifically, as shown in FIG. 1, the open-delta winding circuit of the voltage transformer after the parallel detection device is in the normal state in this embodiment, and it is assumed that the DC resistance of the open-delta winding circuit of the voltage transformer is 10Ω, the secondary load resistance is 2000Ω, and the detection device is connected in parallel between the open-delta winding circuit of the voltage transformer and the load. When the detection device outputs a DC current of 0 to 50mA, the voltage across the open-delta winding is approximately U=50mA×10Ω=0.5V based on the circuit structure shown in FIG. 1. In this state, if the actual voltage value detected by the detection device matches 0.5V, for example, they are equal or the error is within the allowable range, then it is determined that the open-delta winding circuit of the voltage transformer is in the normal state. Figure 2 Figure 2 Therefore, in this embodiment, when the detection device outputs a constant DC current controlled at 50mA, if the voltage measured by the detection device is about 0.5V, it is determined that the open-delta winding circuit is in the normal state, and the voltage measured by the detection device will not affect the normal operation of the open-delta winding circuit of the voltage transformer.

[0050] Therefore, in this embodiment, when the detection device outputs a constant DC current controlled at 50mA, if the voltage measured by the detection device is about 0.5V, it is determined that the open-delta winding circuit is in the normal state, and the voltage measured by the detection device will not affect the normal operation of the open-delta winding circuit of the voltage transformer.

[0051] ​In one embodiment of the present application, in the above embodiment, after the direct current value output by the detection device is detected to be constant at the low current threshold, the method further comprises: calculating a second detection value in the short circuit state according to the resistance value of the load side in the short circuit state and the low current threshold; comparing the voltage across the detection device currently detected with the second detection value, and in the case that the voltage matches the second detection value, determining that the open delta winding circuit of the voltage transformer is in the short circuit state.

[0052] Specifically, in the short circuit state, the open delta winding circuit of the voltage transformer after the parallel detection device is as shown in Figure 3 Since the open delta winding circuit is composed of three single-phase voltage transformer residual windings connected in sequence, when the short circuit occurs at the load side and the resistance value of the load side is 2Ω (i.e. the conductor resistance), and the detection device outputs a direct current of 50mA, based on the circuit structure shown in Figure 3 , the voltage across the open delta winding is approximately U=50mA×2Ω=0.1V. In this state, if the actual voltage value detected by the detection device matches 0.1V, for example, they are equal or the error is within the allowable range, it is determined that the open delta winding circuit of the voltage transformer is in the short circuit state.

[0053] Therefore, in the present embodiment, when the detection device outputs a constant direct current controlled at 50mA, due to the short circuit of the open delta winding circuit at the load side, the current is shunted, and the voltage measured by the detection device is approximately 0.1V, it can be determined that the open delta winding circuit is in the short circuit state.

[0054] In one embodiment of the present application, according to the comparison result to determine the state of the open delta winding circuit of the voltage transformer, the method further comprises: in the process of gradually increasing the direct current value output by the detection device, comparing the voltage across the detection device at any direct current value with a preset open circuit fault detection value; and in the case that the voltage reaches the open circuit fault detection value, determining that the open delta winding circuit of the voltage transformer is in the open circuit state.

[0055] In the present embodiment, the open circuit fault detection value is determined based on the resistance value of the secondary load.

[0056] Specifically, in the open circuit state, the open delta winding circuit of the voltage transformer after the parallel detection device is as shown in Figure 4 During the process of the detection device outputting a direct current of 0 to 50mA, all the current flows through the circuit formed by the load. When the current rises to 10mA, based on Figure 4The open-delta winding circuit structure is shown, and the approximate numerical value of the voltage at the two ends of the open-delta winding is U=10 mA*2000 Ω=20 V. The voltage value is greater than the preset open-circuit fault detection value (different open-circuit fault detection values can be set for different load resistance values), and it can be judged that the open-delta winding circuit of the voltage transformer is in an open-circuit state, and there is no need to continue to increase the output direct current to cause the voltage to rise. In this embodiment, the judgment result can be obtained in time when the voltage at the two ends just reaches the open-circuit fault detection value, and the direct current voltage does not have an adverse effect on the open-delta winding circuit of the voltage transformer in this state.

[0057] In an embodiment of the present application, after judging the state of the open-delta winding circuit of the voltage transformer according to the comparison result, the method further comprises: in response to the state of the open-delta winding circuit of the voltage transformer being in an open-circuit state or a short-circuit state, sending fault alarm information to the staff through the detection device.

[0058] Specifically, based on the above embodiment, in the case where it is determined that the current state of the open-delta winding circuit of the voltage transformer is in an open-circuit state or a short-circuit state, the wireless communication module in the detection device can be used to send fault alarm information to the staff, such as sending alarm information in the form of text, voice, etc. to the monitoring equipment of the remote centralized control center or the mobile terminal of the staff, to remind the staff of the current abnormal state, so as to facilitate timely elimination of the abnormality.

[0059] In summary, the detection method for the open-delta winding circuit of the voltage transformer in the embodiments of the present application can accurately and effectively detect the open-circuit and short-circuit of the open-delta winding circuit of the voltage transformer in operation by outputting a low direct current from the detection device and performing voltage detection. When the open-delta winding circuit is in an abnormal state, the related personnel can be reminded in time to eliminate the abnormality, which can prevent the relay protection device from refusing to act or causing the voltage transformer to burn out in the event of a system accident. Moreover, the detection device is set as a constant current source and adopts a low direct current output mode, which can effectively prevent the voltage transformer secondary side from being charged to the primary side, and avoid the adverse effects of the detection device on the voltage transformer. The detection data obtained by the method has a high degree of distinction for judging the state of the open-delta winding circuit of the voltage transformer, and can timely and accurately judge the normal state, open-circuit state or short-circuit state of the open-delta winding circuit. Therefore, the method is conducive to ensuring the safe and stable operation of the voltage transformer and the power system.

[0060] In order to realize the above-mentioned embodiments, the present application further provides a detection system for an open-delta winding circuit of a voltage transformer, Figure 5A structure diagram of a detection system of an open delta winding loop of a voltage transformer is shown in the embodiment of the present application, as shown in the figure, the system comprises: Figure 5

[0061] The setting module 100 is configured to connect the detection device in parallel between the open delta winding loop of the voltage transformer and the secondary load resistor, wherein the detection device outputs an adjustable DC current, and the amplitude of the adjustable DC current is less than or equal to a preset low current threshold.

[0062] The detection module 200 is configured to gradually increase the DC current value output by the detection device within the range of the low current threshold, and continuously detect the voltage across the open delta winding of the voltage transformer under different DC current values through the detection device.

[0063] The judgment module 300 is configured to compare the voltage across the open delta winding under different DC current values with corresponding detection values respectively, and judge the state of the open delta winding loop of the voltage transformer according to the comparison result, wherein the state includes a normal state, an open circuit state and a short circuit state.

[0064] Optionally, in the embodiment of the present application, the judgment module 300 is specifically configured to: in response to the DC current value output by the detection device being constant at the low current threshold, calculate a first detection value in the normal state according to the DC resistance value of the open delta winding loop of the voltage transformer, the resistance value of the secondary load resistor and the low current threshold; compare the voltage across the two ends currently detected by the detection device with the first detection value, and in the case that the voltage across the two ends matches the first detection value, judge that the open delta winding loop of the voltage transformer is in the normal state.

[0065] It should be noted that the foregoing explanation and description of the embodiment of the detection method of the open delta winding loop of the voltage transformer also applies to the system of the embodiment, which will not be described here again.

[0066] ​In summary, the voltage transformer open delta winding loop detection system of the embodiment of the present application can accurately and effectively detect the open circuit and short circuit of the voltage transformer open delta winding loop in operation by connecting the detection device in parallel between the voltage transformer open delta winding loop and the secondary load resistor, outputting low direct current from the detection device and detecting voltage. When the open delta winding loop is in an abnormal state, the system can timely remind relevant personnel to eliminate the abnormality, which can prevent the relay protection device from refusing to act or causing the voltage transformer to burn out in the event of a system accident. Moreover, the system sets the detection device as a constant current source and adopts a low direct current output mode, which can effectively prevent the voltage transformer secondary side from being charged to the primary side, and avoid the adverse effects of the detection device on the voltage transformer. The detection data obtained by the system has high discrimination for judging the state of the voltage transformer open delta winding loop, and can timely and accurately judge the normal state, open circuit state or short circuit state of the open delta voltage loop. Therefore, the system is conducive to ensuring the safe and stable operation of the voltage transformer and the power system

[0067] To achieve the above-mentioned embodiments, the present application further provides an electronic device, comprising: at least one processor; and a memory communicatively connected with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the voltage transformer open delta winding loop detection method according to any one of the above-mentioned first aspect.

[0068] To achieve the above-mentioned embodiments, the present application further provides a computer readable storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement the voltage transformer open delta winding loop detection method according to any one of the above-mentioned first aspect embodiments.

[0069] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0070] Moreover, the terms "first", "second", "third", etc. are used herein only to describe different steps or categories of steps in a claim for patent purposes, and are not to be construed as indicating or implying relative importance of one step to another or a quantity of steps. Thus, features defined with "first", "second" or "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0071] Any process or method descriptions or blocks in flow charts herein, and elsewhere, can be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are possible. In some embodiments, the processes or methods described herein can be accomplished by one or more hardware devices or modules or in changing wired or wireless connections between hardware devices. For example, one or more processors can be configured with one or more software applications or referred to as "programs" to carry out the processes or methods as described herein.

[0072] Logic and / or steps represented in flow charts herein, and elsewhere, can be embodied in computer-readable media, for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or a combination thereof. For purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can specifically include a hardware apparatus, such as a wired or wireless connection made of one or more conductors, or a portable computer diskette made of magnetic material, or a semiconductor-based memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection made of one or more wires (electrical apparatus), a portable computer diskette (magnetic apparatus), a Random Access Memory (RAM), a Read Only Memory (ROM), an Erasable Programmable Read Only Memory (EPROM or Flash memory), an optical fiber (optical apparatus), and a portable Compact Disc Read Only Memory (CDROM). Additionally, the computer-readable medium can be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for instance by optically scanning the paper or other suitable medium, then electronically converted into a form that is comprehensible by a computer, and then stored or otherwise processed and executed by a computer. Furthermore, the computer-readable medium can be a combination of one or more of the foregoing examples, such as a combination of magnetic and semiconductor memory devices.

[0073] It should be understood that parts of the present application can be realized in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be realized as software or firmware stored in a memory and executed by a suitable instruction execution system. As such, if realized in hardware, and in another embodiment, any one or a combination of the following technologies known in the art can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0074] Those skilled in the art can understand that all or part of the steps carried out by the above-mentioned embodiment methods can be completed by programs instructing relevant hardware, and the programs can be stored in a computer readable storage medium, and when the programs are executed, one or a combination of the steps of the method embodiments is included.

[0075] In addition, each functional unit in each embodiment of the present application can be integrated in one processing module, or each unit can be physically present separately, or two or more units can be integrated in one module. The above-mentioned integrated module can be realized in the form of hardware or in the form of a software functional module. The integrated module, if realized in the form of a software functional module and sold or used as an independent product, can also be stored in a computer readable storage medium.

[0076] The above-mentioned storage medium can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A method of detecting an open delta winding loop of a voltage transformer, characterized by, The method comprises the following steps: parallelly connecting a detection device between the open delta winding loop of the voltage transformer and the secondary load resistor, wherein the detection device outputs adjustable direct current, and the adjustable direct current has an amplitude less than or equal to a preset low current threshold value; gradually increasing the direct current value output by the detection device within the range of the low current threshold value, and continuously detecting the voltage across the open delta winding of the voltage transformer under different direct current values by the detection device; comparing the voltage across the open delta winding under different direct current values with corresponding detection values respectively, and judging the state of the open delta winding loop of the voltage transformer according to the comparison result, wherein the state comprises a normal state, an open circuit state and a short circuit state.

2. The method of claim 1, wherein, The judging the state of the open delta winding loop of the voltage transformer according to the comparison result comprises: calculating a first detection value in the normal state according to the direct current resistance value of the open delta winding loop of the voltage transformer, the resistance value of the secondary load resistor and the low current threshold value, in response to the direct current value output by the detection device being constant at the low current threshold value; comparing the voltage across the open delta winding currently detected by the detection device with the first detection value, and judging the open delta winding loop of the voltage transformer as the normal state in the case that the voltage matches the first detection value.

3. The method of claim 2, wherein, After the response to the direct current value output by the detection device being constant at the low current threshold value, the method further comprises: calculating a second detection value in the short circuit state according to the resistance value of the load side in the short circuit state and the low current threshold value; comparing the voltage across the open delta winding currently detected by the detection device with the second detection value, and judging the open delta winding loop of the voltage transformer as the short circuit state in the case that the voltage matches the second detection value.

4. The method of claim 1, wherein, The judging the state of the open delta winding loop of the voltage transformer according to the comparison result comprises: comparing the voltage across the open delta winding under any direct current value with a preset open circuit fault detection value during the gradual increase of the direct current value output by the detection device; judging the open delta winding loop of the voltage transformer as the open circuit state in the case that the voltage reaches the open circuit fault detection value.

5. The method of claim 1, wherein, After the judging the state of the open delta winding loop of the voltage transformer according to the comparison result, the method further comprises: sending fault alarm information to the staff by the detection device in response to the state of the open delta winding loop of the voltage transformer being the open circuit state or the short circuit state.

6. The method of claim 4, wherein, The open circuit fault detection value is determined based on the resistance value of the secondary load resistor, and the low current threshold value is 50 mA.

7. A detection system for an open delta winding circuit of a voltage transformer, characterized in that The method comprises the following modules: a setting module, configured to parallelly connect a detection device between the open delta winding loop of the voltage transformer and the secondary load resistor, wherein the detection device outputs adjustable direct current, and the adjustable direct current has an amplitude less than or equal to a preset low current threshold value; The detection module is configured to gradually increase the DC current value output by the detection device within the range of the low current threshold, and continuously detect the voltage across the open-delta winding of the voltage transformer at different DC current values by the detection device. The judgment module is configured to compare the voltage across the open-delta winding at different DC current values with corresponding detection values respectively, and determine the state of the open-delta winding circuit of the voltage transformer according to the comparison results, wherein the state includes a normal state, an open-circuit state and a short-circuit state.

8. The system of claim 7, wherein, The judgment module is specifically configured to: in response to the DC current value output by the detection device being constant at the low current threshold, calculate a first detection value in the normal state according to the DC resistance value of the open-delta winding circuit of the voltage transformer, the resistance value of the secondary load resistor and the low current threshold; compare the voltage across the open-delta winding currently detected by the detection device with the first detection value, and determine that the open-delta winding circuit of the voltage transformer is in the normal state when the voltage across the open-delta winding matches the first detection value.

9. An electronic device comprising: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the detection method of the open-delta winding circuit of the voltage transformer as claimed in any one of claims 1-6.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the detection method of the open-delta winding circuit of the voltage transformer as claimed in any one of claims 1-6.

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