Leakage protection monitoring method based on alternating current two-phase leakage protector
By obtaining and processing leakage status parameters in the two-phase leakage protector and adjusting the switching mode of the induction component, the problem of inaccurate leakage identification in the prior art is solved, the accuracy of leakage identification is improved, and safe operation is ensured.
Patent Information
- Application Number
- CN202411097518.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-12
- Publication Date
- 2024-12-27
AI Technical Summary
Existing two-phase leakage protectors are difficult to accurately identify AC leakage, resulting in an increased risk of leakage fires and personal electric shock accidents.
The leakage protection monitoring method based on the AC two-phase leakage protector is adopted. By obtaining the single-phase leakage state parameters of the transformer, the leakage phase separation adjustment process is performed, and the switch working mode of the transformer is adjusted to improve the accuracy of leakage recognition.
It effectively improves the accuracy of identifying two-phase AC leakage, ensures the safe operation of the line, and reduces the risk of personal and property losses.
Smart Images
Figure CN119209385A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the technical field of leakage protectors, and in particular to a leakage protection monitoring method based on an AC two-phase leakage protector. Background Art
[0002] Leakage protection is an important technology used in low-voltage distribution networks to prevent leakage fires and personal electric shock casualties. When the low-voltage distribution network is operating normally, there is a normal leakage current (also called residual current) within a certain range of values. This leakage current is mainly the three-phase unbalanced capacitance current of the line to the earth. This leakage current belongs to normal leakage current; in addition, when a single-phase grounding fault occurs (after a person or object touches a certain phase conductor), an additional abnormal (fault leakage current) leakage current will be generated. The purpose of leakage protection design is to ensure that the leakage protector does not operate when there is only normal leakage current in the line, so as to ensure the normal operation of the line; when there is fault leakage current, the sum of the normal leakage current and the fault leakage current will exceed the action setting current of the leakage protector, and the line power supply will be cut off to protect the human body from direct or indirect electric shock.
[0003] The leakage protection in the low-voltage distribution network is implemented by a leakage protector, usually a three-phase leakage protector and a two-phase leakage protector. Among them, the existing two-phase leakage protector judges whether there is leakage based on whether there is a difference in the current flowing through the two phases. If the leakage occurs in the middle of the phase difference between the two phases, the components of the two phases are the same, and the leakage cannot be identified, which can easily cause personal safety and property losses. Summary of the invention
[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a leakage protection monitoring method based on an AC two-phase leakage protector, which effectively improves the recognition accuracy of two-phase AC leakage.
[0005] The purpose of this disclosure is achieved through the following technical solutions:
[0006] A leakage protection monitoring method based on an AC two-phase leakage protector comprises: using an AC two-phase leakage protector to perform leakage protection detection on two-phase AC power transmission, the AC two-phase leakage protector comprises: an AC two-phase sensing component and a tripper; the AC two-phase sensing component comprises a mutual inductor, an electronic amplifier and a thyristor, the mutual inductor is used to sense the AC two-phase electric wire, the mutual inductor is also connected to the mutual inductance input end of the electronic amplifier, the leakage protection end of the electronic amplifier is connected to the control end of the thyristor; the tripper is used to be connected to the main switch of the AC two-phase electric wire, the tripper is also connected in series with the thyristor to control the closing and opening states of the main switch of the AC two-phase electric wire;
[0007] The leakage protection monitoring method comprises:
[0008] Obtain the single-phase leakage state parameters of the transformer;
[0009] Performing leakage phase leveling processing on the single-phase leakage state parameter and the preset leakage state parameter to obtain the leakage level difference;
[0010] A trip protection on / off signal is sent to the leakage protection device according to the leakage level difference, so as to adjust the switch working mode of the AC two-phase electric wire sensed by the mutual inductor.
[0011] In one of the embodiments, the obtaining of the single-phase leakage state parameter of the transformer includes: obtaining the single-phase leakage current of the transformer.
[0012] In one of the embodiments, the single-phase leakage state parameter is subjected to leakage phase leveling processing with a preset leakage state parameter to obtain a leakage current level difference, including: obtaining a leveling of the single-phase leakage current with a preset leakage current to obtain a leakage current leveling.
[0013] In one of the embodiments, sending a trip protection on / off signal to a leakage protection device according to the leakage level difference to adjust the switch working mode of the AC two-phase electric wire sensed by the mutual inductor includes: detecting whether the leakage current difference is greater than or equal to a preset current difference; when the leakage current difference is greater than or equal to the preset current difference, sending a leakage trip enable signal to the leakage protection device to start the tripper to disconnect the main switch of the AC two-phase electric wire.
[0014] In one of the embodiments, the detecting whether the leakage current difference is greater than or equal to the preset current difference further includes: when the leakage current difference is less than the preset current difference, sending a leakage tripping disability signal to the leakage protection device to maintain the trip device to close the main switch of the AC two-phase power line.
[0015] In one of the embodiments, the obtaining of the single-phase leakage state parameter of the transformer includes: obtaining the single-phase leakage voltage of the transformer.
[0016] In one embodiment, the single-phase leakage state parameter is subjected to leakage phase leveling processing with a preset leakage state parameter to obtain a leakage voltage difference, including: obtaining a leveling of the single-phase leakage voltage with a preset leakage voltage to obtain a leakage voltage leveling.
[0017] In one of the embodiments, sending a trip protection on / off signal to a leakage protection device according to the leakage voltage difference to adjust the switch working mode of the AC two-phase electric wire sensed by the mutual inductor includes: detecting whether the leakage voltage difference is greater than or equal to a preset voltage difference; when the leakage voltage difference is greater than or equal to the preset voltage difference, sending a leakage trip enable signal to the leakage protection device to start the tripper to disconnect the main switch of the AC two-phase electric wire.
[0018] In one of the embodiments, the detecting whether the leakage current difference is greater than or equal to the preset current difference further includes: when the leakage voltage difference is less than the preset voltage difference, sending a leakage tripping disability signal to the leakage protection device to maintain the trip device to close the main switch of the AC two-phase power line.
[0019] In one of the embodiments, the AC two-phase sensing component further includes a varistor, the varistor is connected to the voltage collection end of the transformer, and the varistor is used to be connected in parallel with the AC two-phase electric wire.
[0020] Compared with the prior art, the present invention has at least the following advantages:
[0021] After collecting the single-phase leakage state parameters, the single-phase leakage situation in the current mutual inductance AC two-phase wire of the transformer is determined, and then the single-phase leakage state parameters are compared with the standard leakage state parameters to facilitate determining the difference between the current single-phase leakage state of the transformer and the standard single-phase leakage state. Finally, according to the above difference value, the leakage protection of the leakage protection device is controlled to adjust the switching state of the AC two-phase wire sensed by the transformer, so that the corresponding AC two-phase wire sensed by the transformer is in the leakage protection state, which effectively improves the recognition accuracy of two-phase AC leakage. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 Flow chart of a leakage protection monitoring method based on an AC two-phase leakage protector in one embodiment;
[0024] Figure 2 Schematic diagram of an AC two-phase leakage protector in one embodiment. DETAILED DESCRIPTION
[0025] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present disclosure are given in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thoroughly and comprehensively understood.
[0026] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.
[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present disclosure. The terms used herein in the specification of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. The term "and / or" used herein includes any and all combinations of one or more related listed items.
[0028] The present disclosure relates to a leakage protection monitoring method based on an AC two-phase leakage protector. In one embodiment, the leakage protection monitoring method based on the AC two-phase leakage protector includes obtaining a single-phase leakage state parameter of a mutual inductor; performing leakage phase leveling processing on the single-phase leakage state parameter and a preset leakage state parameter to obtain a leakage level difference; and sending a trip protection on / off signal to a leakage protection device according to the leakage level difference to adjust a switch operation mode of the AC two-phase electric wire corresponding to the induction of the mutual inductor. After collecting the single-phase leakage state parameters, the single-phase leakage situation in the current mutual inductance AC two-phase wire of the transformer is determined, and then the single-phase leakage state parameters are compared with the standard leakage state parameters to facilitate determining the difference between the current single-phase leakage state of the transformer and the standard single-phase leakage state. Finally, according to the above difference value, the leakage protection of the leakage protection device is controlled to adjust the switching state of the AC two-phase wire sensed by the transformer, so that the corresponding AC two-phase wire sensed by the transformer is in the leakage protection state, which effectively improves the recognition accuracy of two-phase AC leakage.
[0029] See also Figure 1 , which is a flow chart of a leakage protection monitoring method based on an AC two-phase leakage protector according to an embodiment of the present disclosure. Figure 2The AC two-phase leakage protector includes an AC two-phase induction component and a tripper; the AC two-phase induction component includes a mutual inductor, an electronic amplifier and a thyristor, the mutual inductor is used to sense the AC two-phase wire, the mutual inductor is also connected to the mutual inductance input end of the electronic amplifier, the leakage protection end of the electronic amplifier is connected to the control end of the thyristor; the tripper is used to connect to the main switch of the AC two-phase wire, the tripper is also connected in series with the thyristor to control the closing and opening states of the main switch of the AC two-phase wire. The leakage protection monitoring method includes some or all of the following steps.
[0030] S100: Obtain single-phase leakage state parameters of the transformer.
[0031] In this embodiment, the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter is the leakage condition of the single-phase wire after the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase wire.
[0032] S200: performing leakage phase leveling processing on the single-phase leakage state parameter and the preset leakage state parameter to obtain a leakage level difference.
[0033] In this embodiment, the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter is the leakage condition on the single-phase wire after the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage condition of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the degree of difference in leakage components appearing in each phase after the mutual inductance of the mutual inductor to the AC two-phase wire.
[0034] S300: Sending a trip protection on / off signal to a leakage protection device according to the leakage level difference, so as to adjust a switch operation mode of the AC two-phase electric wire sensed by the mutual inductor.
[0035] In this embodiment, the leakage level difference is obtained based on the single-phase leakage state parameter and the preset leakage state parameter, and the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter is the leakage condition on the single-phase wire after the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductance detecting the AC two-phase wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage condition of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the difference degree of leakage components appearing in each phase after the mutual inductance of the mutual inductor to the AC two-phase electric wire. After obtaining the leakage level difference, by sending a trip protection on-off signal to the leakage protection device, it is convenient to adjust the switch state of the AC two-phase electric wire through the leakage protection device, so as to facilitate the leakage protection of the AC two-phase electric wire. Specifically, by controlling the trip in the leakage protection device, the closing and opening states of the main switch of the AC two-phase electric wire are switched to realize the on-off control of the AC two-phase electric wire, thereby realizing two-phase leakage protection.
[0036] In the above embodiment, after the single-phase leakage state parameters are collected, the single-phase leakage situation in the current mutual inductance AC two-phase wire of the transformer is determined, and then the single-phase leakage state parameters are compared with the standard leakage state parameters to facilitate determining the difference between the current single-phase leakage state of the transformer and the standard single-phase leakage state. Finally, according to the above difference value, the leakage protection of the leakage protection device is controlled to adjust the switching state of the AC two-phase wire sensed by the transformer, so that the AC two-phase wire sensed by the transformer is in a leakage protection state, which effectively improves the recognition accuracy of the two-phase AC leakage.
[0037] In one of the embodiments, the acquisition of the single-phase leakage state parameter of the mutual inductor includes: acquiring the single-phase leakage current of the mutual inductor. In this embodiment, the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter is the leakage condition of the single-phase electric wire after the mutual inductance of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase electric wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase electric wire. The single-phase leakage state parameter includes the single-phase leakage current of the mutual inductor, and the single-phase leakage current is the leakage current of a single phase in the AC two-phase electric wire sensed by the mutual inductor. By collecting the single-phase leakage current, it is convenient to determine the leakage condition of each phase in the AC two-phase electric wire.
[0038] Furthermore, the single-phase leakage state parameter is subjected to leakage phase leveling processing with a preset leakage state parameter to obtain a leakage level difference, including: obtaining the leveling of the single-phase leakage current with the preset leakage current to obtain a leakage current leveling. In the present embodiment, the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter is the leakage condition on the single-phase electric wire after the mutual inductance of the mutual inductance to the AC two-phase electric wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase electric wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase electric wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage state of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the difference degree of leakage components appearing in each phase after the mutual inductance of the mutual inductance to the AC two-phase wire. The single-phase leakage state parameter includes the single-phase leakage current of the mutual inductance, and the single-phase leakage current is the leakage current of a single phase in the AC two-phase wire sensed by the mutual inductance. By collecting the single-phase leakage current, it is convenient to determine the leakage condition of each phase in the AC two-phase wire. By obtaining the leveling of the single-phase leakage current and the preset leakage current, the difference degree of leakage corresponding to each phase in the AC two-phase wire sensed by the mutual inductance is obtained.
[0039] Furthermore, the sending of a trip protection on / off signal to the leakage protection device according to the leakage level difference to adjust the switch operation mode of the AC two-phase wire sensed by the mutual inductor includes: detecting whether the leakage current balance is greater than or equal to the preset current balance; when the leakage current balance is greater than or equal to the preset current balance, sending a leakage trip enable signal to the leakage protection device to start the tripper to disconnect the main switch of the AC two-phase wire. In this embodiment, the leakage level difference is obtained based on the single-phase leakage state parameter and the preset leakage state parameter, and the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter is the leakage condition of the single-phase wire after the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor to the AC two-phase wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor on the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductor on the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage state of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the difference degree of leakage components appearing in each phase after the mutual inductance of the mutual inductor on the AC two-phase wire. After obtaining the leakage level difference, by sending a trip protection on-off signal to the leakage protection device, it is convenient to adjust the switch state of the AC two-phase wire through the leakage protection device, so as to facilitate the leakage protection of the AC two-phase wire. Specifically, by controlling the trip in the leakage protection device, the closing and opening states of the main switch of the AC two-phase wire are switched to realize the on-off control of the AC two-phase wire, thereby realizing two-phase leakage protection. The single-phase leakage state parameter includes the single-phase leakage current of the mutual inductor, which is the leakage current of a single phase in the two-phase AC wire sensed by the mutual inductor. By collecting the single-phase leakage current, it is convenient to determine the leakage conditions of each phase in the two-phase AC wire. By taking the difference between the single-phase leakage current and the preset leakage current, the difference in leakage between the corresponding phases in the two-phase AC wire sensed by the mutual inductor can be obtained. The leakage current difference is greater than or equal to the preset current difference, indicating that the leakage current of one of the single-phases in the two-phase AC wire sensed by the mutual inductor is too large. At this time, a leakage trip enable signal is sent to the leakage protection device to start the tripper to disconnect the main switch of the two-phase AC wire, so that the two-phase AC wire is changed from the on state to the off state, thereby realizing two-phase leakage protection of the two-phase AC wire.
[0040] In another embodiment, the detection of whether the leakage current balance is greater than or equal to the preset current balance further includes: when the leakage current balance is less than the preset current balance, sending a leakage tripping disabling signal to the leakage protection device to maintain the trip device closing the main switch of the AC two-phase wire. In this embodiment, the leakage current balance is less than the preset current balance, indicating that the mutual inductor senses that the leakage current of each single phase of the AC two-phase wire is within a safe range. At this time, a leakage tripping disabling signal is sent to the leakage protection device to maintain the trip device closing the main switch of the AC two-phase wire, so that the AC two-phase wire continues to maintain a conducting state.
[0041] In one of the embodiments, the acquisition of the single-phase leakage state parameter of the mutual inductor includes: acquiring the single-phase leakage voltage of the mutual inductor. In this embodiment, the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter is the leakage condition of the single-phase electric wire after the mutual inductance of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase electric wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase electric wire. The single-phase leakage state parameter includes the single-phase leakage voltage of the mutual inductor, and the single-phase leakage voltage is the leakage voltage of a single phase in the AC two-phase electric wire sensed by the mutual inductor. By collecting the single-phase leakage voltage, it is convenient to determine the leakage condition of each phase in the AC two-phase electric wire.
[0042] Furthermore, the single-phase leakage state parameter is subjected to leakage phase leveling processing with a preset leakage state parameter to obtain a leakage level difference, including: obtaining the leveling of the single-phase leakage voltage with the preset leakage voltage to obtain a leakage voltage leveling. The single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor to the AC two-phase electric wire, that is, the single-phase leakage state parameter is the leakage condition on the single-phase electric wire after the mutual inductance of the mutual inductance to the AC two-phase electric wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase electric wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor detecting the AC two-phase electric wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductance to the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage state of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the difference degree of leakage components appearing in each phase after the mutual inductance of the mutual inductance to the AC two-phase wire. The single-phase leakage state parameter includes the single-phase leakage voltage of the mutual inductance, and the single-phase leakage voltage is the leakage voltage of a single phase in the AC two-phase wire sensed by the mutual inductance. By collecting the single-phase leakage voltage, it is convenient to determine the leakage condition of each phase in the AC two-phase wire. By obtaining the leveling of the single-phase leakage voltage and the preset leakage voltage, the difference degree of leakage corresponding to each phase in the AC two-phase wire sensed by the mutual inductance is obtained.
[0043] Furthermore, the sending of a trip protection on / off signal to the leakage protection device according to the leakage level difference to adjust the switch operation mode of the AC two-phase wire corresponding to the induction of the mutual inductor includes: detecting whether the leakage voltage difference is greater than or equal to the preset voltage difference; when the leakage voltage difference is greater than or equal to the preset voltage difference, sending a leakage trip enable signal to the leakage protection device to start the tripper to disconnect the main switch of the AC two-phase wire. In this embodiment, the leakage level difference is obtained based on the single-phase leakage state parameter and the preset leakage state parameter, and the single-phase leakage state parameter is the mutual inductance single-phase leakage data of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter is the leakage condition of the single-phase wire after the mutual inductance of the mutual inductor to the AC two-phase wire, that is, the single-phase leakage state parameter corresponds to the leakage condition of one phase on the AC two-phase wire. By collecting the single-phase leakage state parameter, it is convenient to determine the single-phase leakage condition of the mutual inductor to the AC two-phase wire. The preset leakage state parameter is the standard mutual inductance single-phase leakage data of the mutual inductance of the mutual inductor on the AC two-phase wire, that is, the preset leakage state parameter is the leakage condition on the reference single-phase wire after the mutual inductance of the mutual inductor on the AC two-phase wire, that is, the preset leakage state parameter corresponds to the specified leakage state of one phase on the AC two-phase wire. After the leakage phase leveling processing of the single-phase leakage state parameter and the preset leakage state parameter, it is convenient to determine the difference degree of leakage components appearing in each phase after the mutual inductance of the mutual inductor on the AC two-phase wire. After obtaining the leakage level difference, by sending a trip protection on-off signal to the leakage protection device, it is convenient to adjust the switch state of the AC two-phase wire through the leakage protection device, so as to facilitate the leakage protection of the AC two-phase wire. Specifically, by controlling the trip in the leakage protection device, the closing and opening states of the main switch of the AC two-phase wire are switched to realize the on-off control of the AC two-phase wire, thereby realizing two-phase leakage protection. The single-phase leakage state parameter includes the single-phase leakage voltage of the mutual inductor, which is the leakage voltage of a single phase in the two-phase AC wire sensed by the mutual inductor. By collecting the single-phase leakage voltage, it is convenient to determine the leakage conditions of each phase in the two-phase AC wire. By obtaining the difference between the single-phase leakage voltage and the preset leakage voltage, the difference in leakage between the corresponding phases in the two-phase AC wire sensed by the mutual inductor can be obtained. The leakage voltage difference is greater than or equal to the preset voltage difference, indicating that the leakage voltage of one of the single-phases in the two-phase AC wire sensed by the mutual inductor is too large. At this time, a leakage trip enable signal is sent to the leakage protection device to start the tripper to disconnect the main switch of the two-phase AC wire, so that the two-phase AC wire is changed from the on state to the off state, thereby realizing two-phase leakage protection of the two-phase AC wire.
[0044] In another embodiment, the detection of whether the leakage voltage difference is greater than or equal to the preset voltage difference further includes: when the leakage voltage difference is less than the preset voltage difference, sending a leakage tripping disabling signal to the leakage protection device to maintain the trip device closing the main switch of the AC two-phase wire. In this embodiment, the leakage voltage difference is less than the preset voltage difference, indicating that the mutual inductor senses that the leakage voltage of each single phase of the AC two-phase wire is within a safe range. At this time, a leakage tripping disabling signal is sent to the leakage protection device to maintain the trip device closing the main switch of the AC two-phase wire, so that the AC two-phase wire continues to maintain a conducting state.
[0045] In the actual leakage detection process of the two-phase AC electric wire, the detected single-phase leakage state parameters are affected by the phase change of the AC and need to be compared according to the different phases, that is, there are four phase quadrants for comparison, which not only increases the amount of leakage detection data processing, but also increases the difficulty of leakage detection, resulting in low leakage detection efficiency.
[0046] In order to improve the leakage detection efficiency, the acquisition of the single-phase leakage state parameter of the transformer specifically includes the following steps:
[0047] Obtaining a two-phase leakage current phase difference of the mutual inductor and a corresponding single-phase leakage current detection effective value;
[0048] Detecting whether the two-phase leakage phase difference matches a preset phase difference;
[0049] When the two-phase leakage phase difference does not match the preset phase difference, a leakage fractal operation is performed on the two-phase leakage phase difference and the single-phase leakage detection effective value to obtain the single-phase leakage state parameter.
[0050] In this embodiment, the two-phase leakage phase difference is the phase difference between the two-phase alternating current on the two-phase alternating current wires corresponding to the induction of the mutual inductor. Specifically, XOR gate measurement, digital counting, linear approximation, function, and Fourier transform are used. In order to measure the phase difference with high precision, the Fourier transform method is adopted to sample the two phases respectively, and the DFT operation is performed on the sampled sequence x(n), and the initial phase of each of the two phases is directly calculated, so as to calculate the phase difference of the two phases. N represents the number of sampling points, and m is the harmonic order. Here, the fundamental wave is selected, that is, m=1, n is the nth sampling point, the real part of X(m) is Re[X(m)], and the imaginary part is Im[X(m)]. X(m) is obtained by sampling calculation, and then the initial phase Ψ1 is obtained. Similarly, Ψ2 is obtained, and the phase difference |θ|=|Ψ1-Ψ2|. The preset phase difference is the standard phase difference between the two-phase AC on the AC two-phase wire sensed by the mutual inductor, for example, the preset phase difference is within the range of 0≤θ≤π / 2. The two-phase leakage phase difference does not match the preset phase difference, indicating that the phase difference between the two-phase AC on the AC two-phase wire sensed by the mutual inductor exceeds the standard phase difference, that is, indicating that at least one of the leakage components of the two-phase AC on the AC two-phase wire sensed by the mutual inductor is negative, that is, indicating that the phase difference of the two-phase AC on the AC two-phase wire sensed by the mutual inductor appears in the non-first quadrant area. At this time, the single-phase leakage detection effective value of the mutual inductor is sampled to determine the effectiveness of the leakage electrical signal corresponding to each single-phase wire on the AC two-phase wire. Effective value, and, at the same time, a leakage fractal operation is performed on the two-phase leakage phase difference and the single-phase leakage detection effective value. Specifically, the single-phase leakage state parameter is obtained by multiplying the absolute value of the two-phase leakage phase difference by the single-phase leakage detection effective value, so that the leakage detection data of the single-phase leakage state parameter does not need to be adjusted due to different phase difference regions, and there is no need to consider the quadrant region where the phase difference between the two-phase AC wires is located, which effectively reduces the data processing amount of the single-phase leakage state parameter, thereby reducing the difficulty of data processing of the single-phase leakage state parameter.
[0051] Furthermore, the detecting whether the two-phase leakage phase difference matches the preset phase difference further includes:
[0052] When the two-phase leakage phase difference matches the preset phase difference, detecting whether the single-phase leakage detection effective value is less than or equal to the preset single-phase effective value;
[0053] When the single-phase leakage detection effective value is less than or equal to the preset single-phase effective value, a leakage matching operation is performed on the two-phase leakage phase difference and the single-phase leakage detection effective value to obtain the single-phase leakage state parameter.
[0054] In this embodiment, the two-phase leakage phase difference matches the preset phase difference, indicating that the phase difference between the two-phase alternating current on the two-phase alternating current wire corresponding to the induction of the mutual inductor is within the standard phase difference range, that is, the leakage components of the two-phase alternating current on the two-phase alternating current wire corresponding to the induction of the mutual inductor are all positive values, that is, the phase difference of the two-phase alternating current on the two-phase alternating current wire corresponding to the induction of the mutual inductor appears in the first quadrant area. The preset single-phase effective value is the standard equivalent leakage value of each corresponding electrical signal on the AC two-phase electric wire sensed by the mutual inductor. The single-phase leakage detection effective value is less than or equal to the preset single-phase effective value, indicating that the leakage value of each corresponding electrical signal on the AC two-phase electric wire sensed by the mutual inductor is too low, which is not conducive to leakage detection. At this time, the two-phase leakage phase difference and the single-phase leakage detection effective value are subjected to leakage matching operation. Specifically, the leakage detection effective value of one phase of the AC two-phase electric wire is multiplied by the cosine value of the two-phase leakage phase difference, while the leakage detection effective value of the other phase of the AC wire is multiplied by the sine value of the two-phase leakage phase difference. The above two product values are summed to obtain the single-phase leakage state parameter, so as to amplify the leakage detection amount of the AC two-phase electric wire, thereby facilitating accurate detection of the leakage situation on the AC two-phase electric wire.
[0055] In another embodiment, when the single-phase leakage detection effective value is greater than the preset single-phase effective value, the single-phase leakage detection effective value on any phase is selected as the single-phase leakage state parameter.
[0056] In another embodiment, the single-phase leakage detection effective value includes at least one of an effective value of a single-phase leakage current and an effective value of a single-phase leakage voltage.
[0057] In another embodiment, the AC two-phase induction component further includes a varistor, which is connected to the voltage collection terminal of the transformer and is used to be connected in parallel with the AC two-phase wire. The mutual inductance voltage on the AC two-phase wire is collected by the varistor, so as to facilitate the collection of single-phase leakage current and single-phase leakage voltage in the AC power.
[0058] The above-mentioned embodiments only express several implementation methods of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present disclosure, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure shall be subject to the attached claims.
Claims
1. A leakage protection monitoring method based on an AC two-phase leakage protector, characterized in that: include: An AC two-phase leakage protector is used to perform leakage protection detection on two-phase AC power transmission, and the AC two-phase leakage protector includes: An AC two-phase induction component, the AC two-phase induction component includes a mutual inductor, an electronic amplifier and a thyristor, the mutual inductor is used to sense the AC two-phase electric wire, the mutual inductor is also connected to the mutual inductance input terminal of the electronic amplifier, and the leakage protection terminal of the electronic amplifier is connected to the control terminal of the thyristor; A trip device, the trip device is used to be connected to the main switch of the two-phase AC wire, and the trip device is also connected in series with the thyristor to control the closing and opening states of the main switch of the two-phase AC wire; The leakage protection monitoring method comprises: Obtain the single-phase leakage state parameters of the transformer; Performing leakage phase leveling processing on the single-phase leakage state parameter and the preset leakage state parameter to obtain the leakage level difference; A trip protection on / off signal is sent to the leakage protection device according to the leakage level difference, so as to adjust the switch working mode of the AC two-phase electric wire sensed by the mutual inductor.
2. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 1 is characterized in that: The obtaining of the single-phase leakage state parameter of the transformer includes: A single-phase leakage current of the transformer is obtained.
3. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 2 is characterized in that: The step of performing leakage phase leveling processing on the single-phase leakage state parameter and the preset leakage state parameter to obtain the leakage level difference comprises: The difference between the single-phase leakage current and the preset leakage current is obtained to obtain the leakage current difference.
4. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 3 is characterized in that: The method of sending a trip protection on / off signal to a leakage protection device according to the leakage level difference to adjust a switch operation mode of the AC two-phase wire sensed by the mutual inductor comprises: Detecting whether the leakage current balance is greater than or equal to a preset current balance; When the leakage current balance is greater than or equal to the preset current balance, a leakage tripping enable signal is sent to the leakage protection device to start the tripper to disconnect the main switch of the two-phase AC power line.
5. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 4 is characterized in that: The step of detecting whether the leakage current balance is greater than or equal to a preset current balance further includes: When the leakage current balance is less than the preset current balance, a leakage tripping disabling signal is sent to the leakage protection device to maintain the trip device to close the main switch of the AC two-phase electric wire.
6. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 1 is characterized in that: The obtaining of the single-phase leakage state parameter of the transformer includes: A single-phase leakage voltage of the transformer is obtained.
7. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 6 is characterized in that: The step of performing leakage phase leveling processing on the single-phase leakage state parameter and the preset leakage state parameter to obtain the leakage level difference comprises: The difference between the single-phase leakage voltage and the preset leakage voltage is calculated to obtain the leakage voltage difference.
8. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 7 is characterized in that: The method of sending a trip protection on / off signal to a leakage protection device according to the leakage level difference to adjust a switch operation mode of the AC two-phase wire sensed by the mutual inductor comprises: Detecting whether the leakage voltage balance is greater than or equal to a preset voltage balance; When the leakage voltage difference is greater than or equal to the preset voltage difference, a leakage tripping enable signal is sent to the leakage protection device to start the tripper to disconnect the main switch of the two-phase AC power line.
9. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 8 is characterized in that: The step of detecting whether the leakage current balance is greater than or equal to a preset current balance further includes: When the leakage voltage difference is less than the preset voltage difference, a leakage tripping disabling signal is sent to the leakage protection device to maintain the trip device closing the main switch of the AC two-phase electric wire.
10. The leakage protection monitoring method based on the AC two-phase leakage protector according to claim 1 is characterized in that: The AC two-phase induction component also includes a varistor, which is connected to the voltage collection end of the transformer and is used to be connected in parallel with the AC two-phase electric wire.