Capacitive equipment severe case monitoring device and monitoring method

Abstract

The invention discloses a capacitive equipment severe case monitoring device and method, and the device comprises a measurement unit which comprises an acquisition module and a conversion module electrically connected with the acquisition module; the processing module is electrically connected with the measuring unit; and the output module is electrically connected with the processing module. According to the capacitive equipment severe case monitoring device, the insulation state of abnormal equipment can be mastered in time, and the power grid operation risk caused when the equipment runs with a fault is reduced; regular retest work of abnormal equipment is replaced, and manpower and material resources are greatly saved; the personal risk during retest of the abnormal equipment is reduced; the effect of online monitoring can be achieved, and the cost is saved; the device is movable and can be applied to a plurality of substations in turn.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid monitoring, and in particular to a critical monitoring device and a monitoring method for capacitive equipment. Background Art

[0002] Monitoring the insulation performance of capacitive equipment without power outages has become a necessary technical means for the development of power grids. It can improve the timeliness and reliability of the detection rate of defects in capacitive equipment. At present, this technology has been widely used. At present, there are two main monitoring methods in power grids. One is to conduct live monitoring pre-tests on a periodic basis, and the other is to install online monitoring devices. For live monitoring, the main disadvantages are that when the equipment data is abnormal, the accumulated amount of abnormal data is small, the abnormal equipment status cannot be monitored in real time, and personal safety is endangered during re-testing. For online monitoring, the main disadvantages are high cost and high failure rate. For example, for some single equipment such as current transformers and voltage transformers, the installation and maintenance cost of a set of online monitoring devices may exceed the value of the main equipment itself. Summary of the invention

[0003] In view of the above problems existing in the existing capacitive equipment critical care monitoring device, the present invention is proposed.

[0004] Therefore, the purpose of the present invention is to provide a capacitive device critical care monitoring device, the purpose of which is to solve the problems of high cost and high failure rate in the above-mentioned problems.

[0005] In a first aspect, the present invention provides the following technical solution: a capacitive device critical illness monitoring device, comprising:

[0006] A measuring unit, comprising a collection module and a transformation module electrically connected to the collection module;

[0007] a processing module electrically connected to the measuring unit; and

[0008] An output module electrically connected to the processing module.

[0009] As a preferred solution of the capacitive equipment critical illness monitoring device of the present invention, wherein: the conversion module includes a resistance module R and a lightning arrester F electrically connected to the resistance module R;

[0010] The output end of the lightning arrester F is electrically connected to the acquisition module.

[0011] As a preferred solution of the critical monitoring device for capacitive equipment of the present invention, wherein: the acquisition module includes a current transformer CT, and an analog-to-digital converter A / D electrically connected to the output end of the current transformer CT;

[0012] The input end of the current transformer CT is electrically connected to the input / output signal In and the input signal Ix respectively;

[0013] Wherein, the acquisition modules are provided in two groups.

[0014] As a preferred solution of the capacitive device critical illness monitoring device of the present invention, wherein: the input end of the processing module is electrically connected to the analog-to-digital converter A / D;

[0015] The processing module performs transformation processing through the FFT algorithm to obtain the fundamental wave phase Ph(ns) and the fundamental wave phase Ph(xs).

[0016] As a preferred solution of the capacitive device critical care monitoring device of the present invention, the output module is used to calculate the phase difference Ph, wherein the calculation formula of the phase difference Ph is:

[0017] Ph = Ph(xs) - Ph(ns);

[0018] Then calculate the dielectric loss Tanδ, the calculation formula is:

[0019]

[0020] As a preferred solution of the capacitive equipment critical care monitoring device of the present invention, the current transformer CT adopts a core-through structure, and the core-through hole diameter is Φ25mm.

[0021] In a second aspect, the present invention provides the following technical solution: a monitoring method of a capacitive device critical care monitoring device, comprising the following steps:

[0022] Install critical care monitoring equipment and obtain detection information;

[0023] Process the acquired detection information to obtain stable information;

[0024] The stability information is calculated to obtain the dielectric loss.

[0025] As a preferred embodiment of the monitoring method of the capacitive device critical care monitoring apparatus described in the present invention, when acquiring detection information, a monitoring time boundary value is set. When the monitoring time is less than the boundary value, it is judged as short-term monitoring; when the monitoring time is not less than the boundary value, it is judged as long-term monitoring.

[0026] As a preferred solution of the monitoring method of the capacitive device critical care monitoring device of the present invention, wherein: when the acquired detection information is processed, the following steps are included:

[0027] Select stand-alone measurement mode or online measurement mode;

[0028] The steps of the stand-alone measurement mode include: using a single critical care monitoring device for testing, and entering the stand-alone test in the setting interface, and selecting a capacitive device or a lightning arrester according to the type of the device under test;

[0029] The steps of the online measurement mode include: connecting a single critical care monitoring device and an operating device, entering a selection interface and setting it to a synchronous mode.

[0030] As a preferred solution of the monitoring method of the capacitive device critical care monitoring device of the present invention, wherein: when the critical care monitoring device is installed, the side of the cable with the shielded grounding end is connected to the current input terminal in the critical care monitoring box, and the shielded grounding end is connected to the grounding bolt of the critical care monitoring box;

[0031] Remove the plug of the reserved wire inlet hole at the bottom of the live test terminal box and install the waterproof connector;

[0032] The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal post;

[0033] Tighten the waterproof connectors of the live test terminal box and the cable inlet of the critical care monitoring box;

[0034] After the cable connection is completed, open the short-circuit and knife switch of the live test terminal box in sequence.

[0035] Wiring steps for reference unit voltage input:

[0036] After the critical care monitoring box is firmly fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal in the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the monitoring box;

[0037] The other end of the signal cable is connected to the PT secondary terminal of the same bus as the device under test;

[0038] Tighten the waterproof connector of the cable inlet of the intensive care monitoring box.

[0039] The beneficial effects of the present invention are as follows: the insulation status of abnormal equipment can be grasped in time, and the risk of power grid operation caused by the equipment running with defects can be reduced; the regular retesting of abnormal equipment can be replaced, saving a lot of manpower and material resources; the personal risk during the retesting of abnormal equipment can be reduced; the effect of online monitoring can be achieved, saving costs; it is mobile and can be used in multiple substations in turn. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0041] Figure 1 It is a schematic diagram of the overall structure of the capacitive equipment critical care monitoring device of the present invention.

[0042] Figure 2 It is a flow chart of the monitoring method of the capacitive equipment critical care monitoring device of the present invention.

[0043] Figure 3 It is a schematic diagram of the operating interface of the test unit of the monitoring method of the capacitive equipment critical monitoring device of the present invention.

[0044] Figure 4 It is a schematic diagram of the remote transmission setting interface of the monitoring method of the capacitive equipment critical monitoring device of the present invention.

[0045] Figure 5 The present invention is a schematic diagram of the test software interface of the monitoring method of the capacitive equipment critical care monitoring device.

[0046] Figure 6 It is a schematic diagram of the system configuration interface of the monitoring method of the capacitive equipment critical care monitoring device of the present invention. DETAILED DESCRIPTION

[0047] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0048] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0049] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0050] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0051] Example 1

[0052] Reference Figure 1 , which is the first embodiment of the present invention, provides a capacitive device critical illness monitoring device,

[0053] This device includes,

[0054] A measuring unit, comprising a collection module and a transformation module electrically connected to the collection module;

[0055] a processing module electrically connected to the measuring unit; and

[0056] An output module electrically connected to the processing module.

[0057] Further, the conversion module includes a resistance module R and a lightning arrester F electrically connected to the resistance module R;

[0058] The output end of the lightning arrester F is electrically connected to the acquisition module;

[0059] The setting of the conversion module can convert the secondary voltage signal Un of the bus PT and output it as a current signal In.

[0060] Furthermore, the acquisition module includes a current transformer CT, and an analog-to-digital converter A / D electrically connected to the output end of the current transformer CT;

[0061] The input end of the current transformer CT is electrically connected to the input / output signal In and the input signal Ix respectively;

[0062] Wherein, the acquisition module is provided with two groups;

[0063] Through the setting of the acquisition module, the current signal In is collected, and because two groups are set, the end-screen current signal Ix is also synchronously collected.

[0064] The input end of the processing module is electrically connected to the analog-to-digital converter A / D;

[0065] The processing module performs transformation processing through the FFT algorithm to obtain the fundamental wave phase Ph(ns) and the fundamental wave phase Ph(xs);

[0066] When the fundamental wave phase Ph(ns) and the fundamental wave phase Ph(xs) are calculated, the output of monitoring data can be completed, which is convenient for the staff to query the equipment under test.

[0067] Furthermore, the output module is used to calculate the phase difference Ph, wherein the calculation formula of the phase difference Ph is:

[0068] Ph = Ph(xs) - Ph(ns);

[0069] Then calculate the dielectric loss Tanδ, the calculation formula is:

[0070]

[0071] The accuracy of the calculated results is ensured by setting the calculation formulas for the phase difference Ph and the dielectric loss Tanδ.

[0072] Furthermore, the current transformer CT adopts a through-core structure, and the through-core hole diameter is Φ25mm;

[0073] When detecting the industrial frequency current signal of 100μA~1000mA, the phase conversion error is no more than ±0.01° and is not affected by the ambient temperature and electromagnetic interference, which fundamentally solves the problem of accurate sampling of the end-screen current signal of the capacitive device.

[0074] During use, the dielectric loss measurement of capacitive equipment usually requires the bus voltage to be used as the reference for phase measurement. The traditional processing method is to directly provide the secondary voltage signal of the bus PT to the detection system. Its main disadvantages are complex on-site wiring, and the reference voltage signal is susceptible to electromagnetic interference during long-distance transmission, which may cause distortion of dielectric loss measurement results, and the safety of sampling is difficult to guarantee. With the help of advanced fieldbus control technology and high-precision phase measurement technology, the SIM3 monitoring system first proposed and adopted a novel phase comparison measurement method, namely Figure 1 As shown, the sampling problem of the reference voltage signal is well solved, and the phase difference of the fundamental components of the two measured current signals can be accurately obtained;

[0075] The secondary voltage signal Un of the busbar PT is converted into a current signal In through a resistor R, and is detected by a reference unit installed under the PT, while the end-screen current signal Ix of the capacitive device is detected by a measuring unit. Under the control of the central processor, the signal acquisition systems of the two measuring units are started simultaneously, and the analog voltage signals output by the sensors are synchronously sampled and processed by FFT transformation to obtain the fundamental phase Ph (ns) and fundamental phase Ph (xs) of the input signals Un and Ux relative to the 220Vac working power supply Us;

[0076] The central processing unit reads the corresponding phase measurement results to calculate the phase difference Ph of the end screen current signal Ix of the capacitive device relative to the bus voltage Un, thereby obtaining its insulation parameters such as dielectric loss Tanδ and capacitance Cx.

[0077] Example 2

[0078] Reference Figure 1 , which is the second embodiment of the present invention, and the difference between this embodiment and the first embodiment is: a monitoring method of a capacitive equipment critical monitoring device, comprising the following steps,

[0079] S1. Install the critical care monitoring device and obtain detection information.

[0080] S2. Process the acquired detection information to obtain stable information.

[0081] When acquiring detection information, set the monitoring time cutoff value. When the monitoring time is less than the cutoff value, it is judged as short-term monitoring; when the monitoring time is not less than the cutoff value, it is judged as long-term monitoring.

[0082] For example, in short-term monitoring, you only need to fix the two units of the monitoring system near the equipment to be monitored and connect the signal. The system will then measure the equipment under test at regular intervals and transmit the monitoring data to the background system via wireless remote transmission. This not only improves work efficiency but also greatly reduces production costs. Through classification and judgment, it can achieve the effect of cost saving.

[0083] When the acquired detection information is processed, the following steps are included:

[0084] Select stand-alone measurement mode or online measurement mode;

[0085] The steps of the stand-alone measurement mode include: using a single critical care monitoring device for testing, and entering the stand-alone test in the setting interface, and selecting a capacitive device or a lightning arrester according to the type of the device under test;

[0086] The steps of the online measurement mode include: connecting a single critical care monitoring device to an operating device (laptop computer, etc.), entering a selection interface and setting it to a synchronization mode;

[0087] In this embodiment, if Figure 3As shown, after the test unit is powered on and self-tested, the test mode selection interface will pop up. If the user does not operate within 5 seconds, the default mode will be used. When controlling a single instrument through a laptop to perform a single-machine test, the laptop and the test unit should be connected with a network cable. The test unit must be set to "single-machine test" mode. After entering the main interface displayed by the test unit, the current sampling mode will be displayed: "Channel-Rate". Press the "↑" or "↓" key to enter the setting interface, select "Synchronous Mode" to set the rate, and enter the channel selection after confirming. During online testing, the synchronization mode (rate, channel) of the main control unit must be consistent with that of the controlled unit. It is recommended to give priority to the high-speed communication mode. If the signal is unstable, select the medium-speed or low-speed mode in turn;

[0088] In the stand-alone measurement mode, press the "↑" or "↓" key on the instrument main interface to enter the setting interface, select "Stand-alone Test", select "Capacitive Device" or lightning arrester according to the type of device under test, and press the "OK" key to start or stop the measurement. In the stand-alone measurement, the CH1 channel of the main control unit (or controlled unit) should be connected to the reference signal, and the CH2 channel should be connected to the measured signal.

[0089] When installing the critical care monitoring device, connect the side of the cable with the shielded grounding end to the current input terminal in the critical care monitoring box, note that the phase difference and the core color should correspond, and connect the shielded grounding end to the grounding bolt of the critical care monitoring box;

[0090] Remove the plug of the reserved wire inlet hole at the bottom of the live test terminal box and install the waterproof connector;

[0091] The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal post. Note that the phases and core colors should correspond.

[0092] Tighten the waterproof connectors of the live test terminal box and the cable inlet of the critical care monitoring box;

[0093] After the cable connection is completed, open the short-circuit and knife switch of the live test terminal box in sequence.

[0094] Wiring steps for reference unit voltage input:

[0095] After the critical care monitoring box is firmly fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal in the critical care monitoring box. Note that the phase difference and the core color should correspond, and the shielded grounding end should be connected to the grounding bolt of the monitoring box.

[0096] The other end of the signal cable is connected to the PT secondary terminal of the same bus as the device under test, and note that the phase difference and the core color should correspond;

[0097] Tighten the waterproof connector of the cable inlet of the intensive care monitoring box.

[0098] In this embodiment, remote transmission settings are also required to enable router NAT port mapping: log in to the LAN router through the computer receiving data. The router IP is usually 192.168.1.1. Enter Transmission Control-Forwarding Rules-Virtual Server, enable NAT DMZ service, set the host address to the local LAN address, the server name is self-made, the external / internal port is 5002, the service protocol is TCP / UDP, the server IP is the local LAN address, enable the rule and save the modification. Figure 4 shown.

[0099] like Figure 5 As shown, when operating the test software, turn on the power of the two test units after the test cables are connected, and use the network cable to connect the measurement unit to the computer. When the measurement unit is successfully connected to the laptop, you can run the "RCD3 Capacitive Device Critical Monitoring System Software" for testing;

[0100] like Figure 6 As shown, the system needs to be configured for the first test. Select "Remote Parameter Setting" in the menu bar, click "Timing Parameter Setting" to open the timing parameter setting interface, first obtain the system time of the reference unit and the measurement unit. If the two are inconsistent with the computer system time, click the "Sync with Computer" button to synchronize them with the computer.

[0101] If the server address of the receiving data changes during remote data transmission, the new server address needs to be set and maintained in the server address bar. Other parameters do not need to be changed. Set the password to "rcd3".

[0102] The "internal parameter settings" and "external parameter settings" of the instrument have been calibrated before leaving the factory. Do not change them at will, otherwise it will affect the measurement accuracy.

[0103] After the configuration is completed, select "Remote Parameter Setting" from the menu bar, click "Start Timed Monitoring", and the online monitoring parameter setting interface will pop up, as shown in the figure below. Click the "Communication Test" button in the lower left corner to test the communication quality between the current measurement unit and the reference unit; click the "Get Initial Measurement Data" button to perform a measurement to check whether the wiring and settings are correct. If the initial measurement data is normal, click the "Start Timed Monitoring" button to enter the timed monitoring mode.

[0104] S3. Calculate the stability information to obtain the dielectric loss.

[0105] Combined with Figures 1 to 6As shown, the insulation status of abnormal equipment can be grasped in time, reducing the risk of grid operation caused by equipment running with defects; replacing the regular retesting of abnormal equipment, saving a lot of manpower and material resources; reducing the personal risk during retesting of abnormal equipment; achieving the effect of online monitoring and saving costs; being mobile, it can be used in multiple substations in turn.

[0106] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0107] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0108] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A capacitive equipment critical illness monitoring device, characterized in that: include, A measuring unit, comprising a collection module and a transformation module electrically connected to the collection module; a processing module electrically connected to the measuring unit; as well as, An output module electrically connected to the processing module.

2. The capacitive device critical illness monitoring device according to claim 1, characterized in that: The conversion module includes a resistance module R and a lightning arrester F electrically connected to the resistance module R; The output end of the lightning arrester F is electrically connected to the acquisition module.

3. The capacitive device critical illness monitoring device according to claim 2, characterized in that: The acquisition module includes a current transformer CT, and an analog-to-digital converter A / D electrically connected to the output end of the current transformer CT; The input end of the current transformer CT is electrically connected to the input / output signal In and the input signal Ix respectively; Wherein, the acquisition modules are provided in two groups.

4. The capacitive device critical illness monitoring device according to claim 3, characterized in that: The input end of the processing module is electrically connected to the analog-to-digital converter A / D; The processing module performs transformation processing through the FFT algorithm to obtain the fundamental wave phase Ph(ns) and the fundamental wave phase Ph(xs).

5. The capacitive device critical illness monitoring device according to claim 4, characterized in that: The output module is used to calculate the phase difference Ph, wherein the calculation formula of the phase difference Ph is: Ph = Ph(xs) - Ph(ns); Then calculate the dielectric loss Tanδ, the calculation formula is:

6. The capacitive device critical illness monitoring device according to claim 5, characterized in that: The current transformer CT adopts a through-core structure, and the through-core hole diameter is Φ25mm.

7. A monitoring method for a capacitive equipment critical care monitoring device, characterized in that: The capacitive device critical illness monitoring device according to claim 6 further comprises the following steps: Install critical care monitoring equipment and obtain detection information; Process the acquired detection information to obtain stable information; The stability information is calculated to obtain the dielectric loss.

8. The capacitive device critical illness monitoring device according to claim 7, characterized in that: When acquiring detection information, set a monitoring time threshold value. When the monitoring time is less than the threshold value, it is judged as short-term monitoring; when the monitoring time is not less than the threshold value, it is judged as long-term monitoring.

9. The monitoring method of the capacitive equipment critical illness monitoring device according to claim 8, characterized in that: When the acquired detection information is processed, the following steps are included: Select stand-alone measurement mode or online measurement mode; The steps of the stand-alone measurement mode include: using a single critical care monitoring device for testing, and entering the stand-alone test in the setting interface, and selecting a capacitive device or a lightning arrester according to the type of the device under test; The steps of the online measurement mode include: connecting a single critical care monitoring device and an operating device, entering a selection interface and setting it to a synchronous mode.

10. The monitoring method of the capacitive equipment critical illness monitoring device according to claim 9, characterized in that: When installing the critical care monitoring device, connect the side of the cable with the shielded grounding end to the current input terminal in the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the critical care monitoring box; Remove the plug of the reserved wire inlet hole at the bottom of the live test terminal box and install the waterproof connector; The other end of the signal cable passes through the waterproof connector of the live test terminal box and is connected to the terminal post; Tighten the waterproof connectors of the live test terminal box and the cable inlet of the critical care monitoring box; After the cable connection is completed, open the short-circuit and knife switch of the live test terminal box in sequence. Wiring steps for reference unit voltage input: After the critical care monitoring box is firmly fixed, first connect the side of the cable with the shielded grounding end to the voltage input terminal in the critical care monitoring box, and connect the shielded grounding end to the grounding bolt of the monitoring box; The other end of the signal cable is connected to the PT secondary terminal of the same bus as the device under test; Tighten the waterproof connector of the cable inlet of the intensive care monitoring box.

Images