Low-voltage dual-power-supply loop closing monitoring device

Abstract

The invention relates to a low-voltage dual-power loop closing monitoring device which comprises a test box body capable of being opened and closed, a monitoring main body is arranged in the box body, and the monitoring main body is provided with a monitoring circuit board, a touch display screen connected with the monitoring circuit board and a group of external ports connected with the monitoring circuit board. The monitoring main body is also provided with a group of indicating lamps and control buttons which are connected with the monitoring circuit board. A closed loop current value calculation unit is arranged in the monitoring circuit board; and the loop closing circulation value calculation unit is used for calculating a loop closing circulation value during loop closing. According to the invention, closed-loop transfer of low-voltage dual power supplies can be realized conveniently and reliably, the power supply reliability of the low-voltage power distribution network is optimized, the economical efficiency is improved, and the investment cost of construction of the low-voltage power distribution network is reduced.

Description

Technical Field

[0001] The invention relates to the field of low-voltage dual-power closed-loop, and in particular to a low-voltage dual-power closed-loop monitoring device. Background Art

[0002] With the rapid development of cities, the density of buildings and various public facilities continues to expand, and the load transfer capacity of the low-voltage distribution network can no longer meet the high reliability requirements of urban electricity consumption. Due to the limitations of existing power transfer equipment technology, there are currently the following pain points:

[0003] The first is the problem of short-term power outages during the low-voltage area interconnection and ring-closing power supply. Due to operational safety considerations, different power sources cannot be directly connected. The current low-voltage area ring-closing operation process and specifications determine that during the ring-closing operation, it is necessary to first shut down the power supply area, connect the transfer cable, and then shut down the power receiving area, connect the transfer cable, and then close the low-voltage interconnection switch. This causes the problem of uncontrollable / too long short-term power outages, which brings inconvenience to corporate production and residents' lives.

[0004] Second, there are safety risks in the closing process, and it is impossible to monitor and warn the closing status in real time. The circulating current and impact current during the low-voltage station connection closing process will cause impact on the station equipment. At present, there is a lack of monitoring methods for station equipment and cables during the operation. In addition, the closing operation generally takes a long time, and the increase in the load of the power supply station will also have a certain impact on the equipment.

[0005] According to the development plan of State Grid Corporation, the construction of high-reliability demonstration areas and high-quality power supply leading areas has higher requirements for the continuity of power supply. Through the connection between low-voltage distribution transformers, reverse power supply is used to improve the reliability of power supply for residents. Therefore, the power supply form of low-voltage distribution network is optimized, and the risks and safety protection specifications of each process of non-stop power transfer are explored. Among them, ring-closing power transfer has become an important research topic to improve the reliability of power supply in low-voltage distribution network. Summary of the invention

[0006] The purpose of the present invention is to provide a low-voltage dual-power supply closed-loop monitoring device, which can conveniently and reliably realize the closed-loop transfer of low-voltage dual power supplies, optimize the power supply reliability of the low-voltage distribution network, and at the same time improve the economy and reduce the investment cost of low-voltage distribution network construction.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a low-voltage dual-power closed-loop monitoring device, comprising an openable and closable test box, a monitoring body arranged in the box, the monitoring body being provided with a monitoring circuit board, a touch screen connected to the monitoring circuit board, a group of external ports connected to the monitoring circuit board, and a group of indicator lights and control buttons connected to the monitoring circuit board; a closed-loop circulating current value calculation unit is arranged in the monitoring circuit board; the closed-loop circulating current value calculation unit is used to calculate the closed-loop circulating current value when the loop is closed;

[0008] The external ports include a first voltage remote control sampling interface, a second power supply remote control sampling interface, a power supply interface, and a current sampling interface;

[0009] A first voltage remote control sampling interface, used to collect the voltage on the first power supply side of the tie switch through an aviation plug;

[0010] A second voltage remote control sampling interface, used to collect the voltage on the second power supply side of the tie switch through an aviation plug;

[0011] Current sampling interface, used to collect the current at the tie switch position after the tie switch is closed;

[0012] The display interface of the touch screen is provided with a set of status display graphics which read the data transmitted by the monitoring circuit board and display the data accordingly, including:

[0013] A first power supply status display graphic, used to display the working status of the first power supply;

[0014] A second power supply status display graphic for the working status of the second power supply;

[0015] The state display graphic of the first power supply side switch of the tie switch is used to display the opening and closing state of the first power supply side switch of the tie switch; and remote wireless communication can be realized through touch to control the change of the opening and closing state;

[0016] The status display graphic of the second power supply side switch of the tie switch is used to display the opening and closing status of the second power supply side switch of the tie switch; and remote wireless communication can be realized through touch to control the change of the opening and closing status;

[0017] The contact switch status display graphic is used to display the open and close status of the contact switch; and can realize remote wireless communication through touch to control the change of the open and close status;

[0018] Operation fault display area, used to display parameter input values ​​in real time and issue an alarm indication when input is missing;

[0019] A phase angle difference display graph is used to display the phase angle difference between the first power supply and the second power supply, and the value is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface;

[0020] A frequency difference display graph is used to display the frequency difference between the first power supply and the second power supply, which value is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface;

[0021] The closed-loop current display graph is used to display the current value at the tie switch position when the loop is closed. This value is measured by the monitoring circuit board through the current sampling interface;

[0022] The parameter input window is used to manually input parameters, including an impedance voltage ratio input unit, a first power capacity input unit, a second power capacity input unit, a first power voltage input unit, and a second power voltage input unit; parameters are input through the touch screen;

[0023] A three-phase voltage value display graph of the first power supply and the second power supply, used to display the three-phase voltage values ​​of the first power supply and the second power supply;

[0024] The closing loop indication graphic is used to indicate whether the closing loop operation can be performed. It includes red light indication, green light indication, and yellow light indication. The red light indication indicates that the closing loop cannot be performed, the green light indication indicates that the closing loop can be performed, and the yellow light indication indicates that the closing loop current value calculated by the closing loop current value calculation unit is equal to the set threshold value, and it can be manually determined whether to close the loop.

[0025] The method for calculating the closed-loop circulation value by the closed-loop circulation value calculation unit is as follows:

[0026] Calculate the per-unit value of the first power supply:

[0027] Among them U K1 is the short-circuit impedance of the first power transformer, S N1 is the capacity of the first power transformer, U N1 is the measured power of the first power source, S B is the system capacity constant;

[0028] Calculate the per-unit value of the second power supply:

[0029] U K2 is the short-circuit impedance of the second power transformer, S N2 is the capacity of the second power transformer, U N2 is the measured power of the second power supply, S B Defined as the system capacity constant;

[0030] Calculate the reference current value under the per unit value:

[0031]

[0032] The voltage difference between the first power supply and the second power supply is:

[0033] UB=U B ∠0°-U N ∠-30°; U N Rated voltage for this voltage level;

[0034] Voltage per unit value of 0.4kV voltage level:

[0035] After the 0.4kV voltage level is closed, the circulating current size when closing is:

[0036]

[0037] Beneficial effects of the present invention: The device collects electrical quantities such as voltage and current of the power supplies on both sides of the contact switch, calculates the voltage difference, phase difference, steady-state current, and transient current of the power supplies on both sides of the closed loop, and thus determines whether the closed loop conditions specified in the regulations are met. During the closed loop process, abnormal conditions should be detected in time, the protection program should be started, and the closed loop switch should be pulled open to avoid voltage fluctuations and overcurrent from damaging the equipment. At the same time, after the maintenance or troubleshooting of a transformer on the receiving side is completed, the closed loop self-recovery function of the power supply on this side is performed, and the voltage on both sides of the incoming line switch of the power supply on this side can be collected and judged, and the voltage difference, phase difference, closed loop current, etc. on both sides of the closed loop point can be calculated, so as to determine whether the closed loop conditions are met and perform the self-recovery function after maintenance.

[0038] In the uninterrupted power supply work of the low-voltage distribution network in traditional ancient villages, not only the power supply reliability of the low-voltage distribution network is optimized, but also the economy is improved, the investment cost of the low-voltage distribution network construction is reduced, and it plays an important demonstration role in the economic, safe and reliable operation of the traditional distribution network.

[0039] The present invention will be described in more detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic diagram of a display interface of a touch display screen.

[0041] Figure 2 A schematic diagram of the parameter setting interface of the touch display screen.

[0042] Figure 3 Another schematic diagram of the parameter setting interface of the touch display screen.

[0043] Among them, 1. The first power supply status display graph, 2. The second power supply status display graph, 3. The status display graph of the first power supply side switch of the interconnecting switch, 4. The status display graph of the second power supply side switch of the interconnecting switch, 5. The interconnecting switch status display graph, 6. The operation fault display area, 7. The phase angle difference display graph, 8. The frequency difference display graph, 9. The closed-loop current display graph, 10. The parameter entry window, 11. The three-phase voltage value display graph of the first power supply and the second power supply, 12. The closed-loop indication graph. DETAILED DESCRIPTION

[0044] Examples, such as Figures 1 to 3 A low-voltage dual-power closed-loop monitoring device shown in the figure comprises an openable and closable test box, a monitoring body is arranged in the box, the monitoring body is provided with a monitoring circuit board, a touch screen connected to the monitoring circuit board, a group of external ports connected to the monitoring circuit board, and a group of indicator lights and control buttons connected to the monitoring circuit board are also arranged on the monitoring body; a closed-loop circulating current value calculation unit is arranged in the monitoring circuit board; the closed-loop circulating current value calculation unit is used to calculate the closed-loop circulating current value when the loop is closed;

[0045] The external ports include a first voltage remote control sampling interface, a second power remote control sampling interface, a power interface, and a current sampling interface;

[0046] A first voltage remote control sampling interface, used to collect the voltage on the first power supply side of the tie switch through an aviation plug;

[0047] A second voltage remote control sampling interface, used to collect the voltage on the second power supply side of the tie switch through an aviation plug;

[0048] Current sampling interface, used to collect the current at the tie switch position after the tie switch is closed;

[0049] The display interface of the touch screen is provided with a set of status display graphics which read the data transmitted by the monitoring circuit board and display the data accordingly, including:

[0050] First power status display Figure 1 , used to display the working status of the first power supply;

[0051] The second power supply status display graphic 2 is used for the working status of the second power supply;

[0052] The state display graphic 3 of the first power supply side switch of the tie switch is used to display the opening and closing states of the first power supply side switch of the tie switch; and remote wireless communication can be realized through touch control to control the change of the opening and closing states;

[0053] The state display graphic 4 of the second power supply side switch of the tie switch is used to display the opening and closing states of the second power supply side switch of the tie switch; and can realize remote wireless communication through touch control to control the change of the opening and closing states;

[0054] The tie switch status display graphic 5 is used to display the opening and closing status of the tie switch; and can realize remote wireless communication through touch control to control the change of the opening and closing status;

[0055] Operation fault display area 6 is used to display parameter input values ​​in real time and issue an alarm indication when input is missing;

[0056] Phase angle difference display graph 7, used to display the phase angle difference between the first power supply and the second power supply, which is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface;

[0057] A frequency difference display graph 8 is used to display the frequency difference between the first power supply and the second power supply, which is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface;

[0058] The closed-loop current display graph 9 is used to display the current value at the tie switch position when the loop is closed, which is measured by the monitoring circuit board through the current sampling interface;

[0059] The parameter input window 10 is used for manually inputting parameters, and includes an impedance voltage ratio input unit, a first power capacity input unit, a second power capacity input unit, a first power voltage input unit, and a second power voltage input unit; the parameters are inputted through the touch screen;

[0060] A three-phase voltage value display graph 11 of the first power supply and the second power supply, used to display the three-phase voltage values ​​of the first power supply and the second power supply;

[0061] The closing loop indication graphic 12 is used to indicate whether the closing loop operation can be performed, and includes a red light indication, a green light indication, and a yellow light indication. The red light indication indicates that the closing loop cannot be performed, the green light indication indicates that the closing loop can be performed, and the yellow light indication indicates that the closing loop current value calculated by the closing loop current value calculation unit is equal to the set threshold value, and it can be manually determined whether to close the loop.

[0062] The method for calculating the closed-loop circulation value by the closed-loop circulation value calculation unit is as follows:

[0063] Calculate the per-unit value of the first power supply:

[0064] Among them U K1 is the short-circuit impedance of the first power transformer, S N1 is the capacity of the first power transformer, U N1 is the measured power of the first power source, S B is the system capacity constant;

[0065] Calculate the per-unit value of the second power supply:

[0066] U K2 is the short-circuit impedance of the second power transformer, S N2 is the capacity of the second power transformer, U N2 is the measured power of the second power supply, S B Defined as the system capacity constant;

[0067] Calculate the reference current value under the per unit value:

[0068]

[0069] The voltage difference between the first power supply and the second power supply is:

[0070] UB=U B ∠0°-U N ∠-30°; U N Rated voltage for this voltage level;

[0071] Voltage per unit value of 0.4kV voltage level:

[0072] After the 0.4kV voltage level is closed, the circulating current size when closing is:

[0073]

[0074] In the description of the present invention, it should be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In addition, the term "including" and any variation thereof are intended to cover non-exclusive inclusions.

[0075] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0077] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A low voltage dual power supply closed loop monitoring device, characterized in that: It includes an openable and closable test box, in which a monitoring body is arranged, the monitoring body is provided with a monitoring circuit board, a touch screen connected to the monitoring circuit board, a group of external ports connected to the monitoring circuit board, and a group of indicator lights and control buttons connected to the monitoring circuit board are also arranged on the monitoring body; a closed-loop circulation value calculation unit is arranged in the monitoring circuit board; the closed-loop circulation value calculation unit is used to calculate the closed-loop circulation value when the loop is closed; The external ports include a first voltage remote control sampling interface, a second power remote control sampling interface, a power interface, and a current sampling interface; A first voltage remote control sampling interface, used to collect the voltage on the first power supply side of the tie switch through an aviation plug; A second voltage remote control sampling interface, used to collect the voltage on the second power supply side of the tie switch through an aviation plug; Current sampling interface, used to collect the current at the tie switch position after the tie switch is closed; The display interface of the touch screen is provided with a set of status display graphics which read the data transmitted by the monitoring circuit board and display the data accordingly, including: A first power supply status display graphic, used to display the working status of the first power supply; A second power supply status display graphic for the working status of the second power supply; The state display graphic of the first power supply side switch of the tie switch is used to display the opening and closing state of the first power supply side switch of the tie switch; and remote wireless communication can be realized through touch to control the change of the opening and closing state; The status display graphic of the second power supply side switch of the tie switch is used to display the opening and closing status of the second power supply side switch of the tie switch; and remote wireless communication can be realized through touch to control the change of the opening and closing status; The tie switch status display graphic is used to display the open and close status of the tie switch; and can realize remote wireless communication through touch to control the change of the open and close status; Operation fault display area, used to display parameter input values ​​in real time and issue an alarm indication when input is missing; A phase angle difference display graph is used to display the phase angle difference between the first power supply and the second power supply, and the value is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface; A frequency difference display graph is used to display the frequency difference between the first power supply and the second power supply, which value is calculated by the data collected by the monitoring circuit board through the first voltage remote control sampling interface and the second voltage remote control sampling interface; The closed-loop current display graph is used to display the current value at the tie switch position when the loop is closed. This value is measured by the monitoring circuit board through the current sampling interface; The parameter input window is used to manually input parameters, including an impedance voltage ratio input unit, a first power capacity input unit, a second power capacity input unit, a first power voltage input unit, and a second power voltage input unit; parameters are input through the touch screen; A three-phase voltage value display graph of the first power supply and the second power supply, used to display the three-phase voltage values ​​of the first power supply and the second power supply; The closing loop indication graphic is used to indicate whether the closing loop operation can be performed. It includes red light indication, green light indication, and yellow light indication. The red light indication indicates that the closing loop cannot be performed, the green light indication indicates that the closing loop can be performed, and the yellow light indication indicates that the closing loop current value calculated by the closing loop current value calculation unit is equal to the set threshold value, and it can be manually determined whether to close the loop.

2. A low-voltage dual-power closed-loop monitoring device according to claim 1, characterized in that: The display interface of the touch screen can also be used to set various circuit parameters of the first power supply and the second power supply.

3. A low-voltage dual-power closed-loop monitoring device according to claim 1 or 2, characterized in that: The method for calculating the closed-loop circulation value by the closed-loop circulation value calculation unit is as follows: Calculate the per-unit value of the first power supply: Among them U< sub>K1 is the short-circuit impedance of the first power transformer, S N1 is the capacity of the first power transformer, U N1 is the measured power of the first power source, S B is the system capacity constant; Calculate the per-unit value of the second power supply: U K2 is the short-circuit impedance of the second power transformer, S N2 is the capacity of the second power transformer, U N2 is the measured power of the second power supply, S B Defined as the system capacity constant; Calculate the reference current value under the per unit value: The voltage difference between the first power supply and the second power supply is: UB=U B ∠0°-U N ∠-30°; U N Rated voltage for this voltage level; Voltage per unit value of 0.4kV voltage level: After the 0.4kV voltage level is closed, the circulating current size when closing is:

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