Power distribution cabinet power-on automatic switching system

Abstract

The power distribution cabinet power-on automatic switching system comprises an automatic switching module, the automatic switching module comprises a shell, and a power supply module, a PLC controller and a three-phase power supply acquisition unit are arranged in the shell; the shell is provided with wiring terminals, and the wiring terminals comprise a power supply terminal, an output terminal and an automatic / manual signal terminal; the power supply terminal is connected with three-phase power, the three-phase power supply acquisition unit is connected with the power supply terminal, and the signal output end of the three-phase power supply acquisition unit is connected with the switching value input end of the PLC; the automatic / manual signal terminal is connected with an automatic / manual signal acquisition unit; the automatic / manual signal acquisition unit is connected with a switching value input end of the PLC; and the output end of the PLC is connected with an energy storage control loop and a closing control loop. The system can automatically execute the closing function according to the delay time set by the user, can solve the time efficiency problem of manual closing, and saves a lot of low-efficiency labor cost for the user.

Description

Technical Field

[0001] The utility model belongs to the technical field of power distribution cabinet incoming power closing, in particular to a power distribution cabinet incoming power automatic switching system. Background Art

[0002] When a power distribution switch cabinet encounters a power outage, its circuit breaker will trip due to undervoltage tripping, causing the coil to lose voltage. When the line is restored to power, the staff must go to the power distribution site to manually close the switch, which is a lot of work and takes a long time to restore power. In order to solve the above problems, the existing technology removes the undervoltage protection of the circuit breaker.

[0003] In summary, the current low-voltage circuit breakers include two operating structures: one with the undervoltage protection removed, and one without the undervoltage protection removed. The scheme of removing the undervoltage protection has the following hazards: after the power grid loses pressure, since the low-voltage circuit breaker cancels the undervoltage tripping function, the low-voltage circuit breaker will remain closed in the case of line fault tripping, power restriction, maintenance, etc. If the power grid resumes power supply, on the one hand, due to operational overvoltage and impact, the voltage quality will deteriorate instantly, causing serious threats or even damage to the equipment. On the other hand, since the low-voltage circuit breakers of all lines remain closed, all user equipment will start at the same time, and the starting current is very large, which is easy to cause instantaneous overload of the line, which is very unfavorable to the safe operation of the power grid.

[0004] There are some shortcomings in the use of low-voltage circuit breakers without the function of undervoltage protection release: first, the low-voltage circuit breaker trips due to instantaneous fluctuations, flickers, and power outages in the power grid, causing users to lose power suddenly. Second, when the operating unit restores power supply, it needs to manually close the circuit breaker, which is labor-intensive and slow.

[0005] The patent application with publication number: CN219144099U discloses an intelligent automatic closing control device, which solves the problem that after removing the undervoltage protection, the low-voltage circuit breakers of all lines remain closed, and all user equipment will start at the same time. The starting current is very large, which easily causes instantaneous overload of the line, which is not conducive to the safe operation of the power grid; on the other hand, it solves the problem that the operating unit needs to manually close the circuit breaker when restoring power supply without removing the undervoltage protection circuit breaker, which is labor-intensive and slow. When the power is turned on, the iron core is energized and the low-voltage circuit breaker is automatically closed.

[0006] However, the application still has the following problems: 1. When the power supply has a phase loss problem, it will also close, which will affect the safety of subsequent electrical equipment to a certain extent. 2. When the circuit breaker is manually disconnected, when there is power passing through the transmission line, the circuit breaker is very likely to malfunction, affecting the personal safety of relevant personnel. Utility Model Content

[0007] The utility model aims to provide a power distribution cabinet automatic power-on system with simple structure and good use effect.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions: a power distribution cabinet incoming call automatic switching system, the three-phase power is connected to the incoming circuit breaker, including an automatic switching module, the automatic switching module includes a shell, and the shell is equipped with a power module, a PLC controller, and a three-phase power acquisition unit; the shell is provided with wiring terminals, the wiring terminals include power terminals, output terminals and automatic / manual signal terminals; the power terminals are connected to the three-phase power, the three-phase power acquisition unit is connected to the power terminals, and the signal output end of the three-phase power acquisition unit is connected to the switch input end of the PLC controller; the automatic / manual signal terminal is connected to the automatic / manual signal acquisition unit, and the automatic / manual signal acquisition unit is connected to the switch input end of the PLC controller; the output end of the PLC controller is connected to the incoming circuit breaker. The energy storage control circuit and the closing control circuit send energy storage signals and closing signals to the output terminals, and the output terminals are connected to the incoming circuit breaker.

[0009] The incoming circuit breaker includes a normally open contact and a normally closed contact; the three-phase electricity L1, L2, and L3 are respectively connected to the A, B, and C phases of the incoming circuit breaker; the normally closed contact of the incoming circuit breaker is connected between the power supply module and the power supply terminal of the PLC controller.

[0010] The three-phase power supply acquisition unit includes three acquisition intermediate relays. The three-phase electricity is respectively connected to the first ends of the three acquisition intermediate relay coils, the second ends of the three acquisition intermediate relay coils are connected to the neutral line, the first ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the switch signal input end of the PLC controller, and the second ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the common end.

[0011] The automatic / manual signal acquisition unit includes a manual button and an automatic button; one end of the manual button / automatic button is connected to the power module, and the other end is connected to the neutral line through the coil of the first intermediate relay / second intermediate relay, one end of the normally open contact of the first intermediate relay / second intermediate relay is connected to the switch signal input end of the PLC controller, and the second end of the normally open contact of the first intermediate relay / second intermediate relay is connected to the common end respectively.

[0012] The normally closed contact of the second intermediate relay is connected between the coil of the first intermediate relay and the neutral line; the normally closed contact of the first intermediate relay is connected between the coil of the second intermediate relay and the neutral line.

[0013] The energy storage control circuit includes an energy storage relay, and the closing control circuit includes a closing relay. The output end of the PLC controller is connected to the coil of the energy storage relay and the coil of the closing relay.

[0014] It also includes a host computer, and there are multiple automatic modules. The PLC controller of each automatic module communicates with the host computer.

[0015] The PLC controller communicates with the host via Ethernet; a first wireless communication terminal is connected to the PLC controller, and a second wireless communication terminal is connected to the host. The PLC controller and the host communicate wirelessly via the first wireless communication terminal and the second wireless communication terminal.

[0016] Through the above technical scheme, the technical effects of the utility model are as follows: 1. If there is a temporary power outage in the power supply area due to external line maintenance or other non-fault reasons, when the external reasons are eliminated, the system can automatically execute the closing function after the delay time set by the user, which can solve the timeliness problem of manual closing and save a lot of inefficient labor costs for users. 2. The system can manage the power distribution cabinets in this area in an integrated manner, so as to perform a separate delay on each one, and avoid the damage to the power grid caused by the simultaneous power supply of multiple box-type substations. 3. The normally closed contacts of the incoming circuit breaker are connected in series between the incoming terminals of the power module and the PLC controller, which increases the service life of the switching module and avoids the heating problem caused by long-term power-on; at the same time, after the incoming circuit breaker is powered off, the normally closed contacts are immediately closed, so that the switching module starts to work, which is a clever design. 4. The three-phase power supply acquisition unit can collect the three-phase power supply, including voltage signal and phase loss signal, to ensure the accuracy of switching action; the automatic / manual signal acquisition unit can collect automatic / manual signals, avoiding the execution of automatic switching action under manual model, thus ensuring the safety of maintenance personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of Example 1;

[0018] Figure 2 This is the circuit schematic diagram of the switching module;

[0019] Figure 3 This is a schematic diagram of Example 2. DETAILED DESCRIPTION

[0020] Embodiment 1, the power distribution cabinet incoming power automatic switching system, this system is applicable to the box-type substation with AC 50HZ (or 60HZ) and voltage of 0.4kV. When the power supply line is restored after power failure, it sends a closing signal to make the incoming circuit breaker QF automatically close.

[0021] like Figure 1 and Figure 2 As shown, when working, the three-phase power is connected to the incoming circuit breaker QF, wherein the incoming circuit breaker QF includes a normally open contact and a normally closed contact; L1, L2, and L3 of the three-phase power are respectively connected to the A, B, and C phases of the incoming circuit breaker QF; the power module supplies power to the PLC controller U1, and the normally closed contact of the incoming circuit breaker QF is connected between the power module and the power supply terminal of the PLC controller U1. Therefore, after the incoming circuit breaker QF is powered on, the automatic transfer module is powered off and exits.

[0022] The system includes an automatic transfer module, which includes a shell 1. The shell 1 is provided with a power supply module, a PLC controller U1, and a three-phase power supply acquisition unit; the shell 1 is provided with wiring terminals, which include power supply terminals 1, 3, 5, output terminals 15, 17, and automatic / manual signal terminals 9, 10; the power supply terminals 1, 3, 5 are respectively connected to the three-phase electricity L1, L2, L3, the three-phase power supply acquisition unit is connected to the power supply terminals 1, 3, 5, and the signal output end of the three-phase power supply acquisition unit is connected to the switch input terminals X1, X2, X3 of the PLC controller U1; the automatic / manual signal terminals 9, 10 are connected to the automatic / manual signal acquisition unit, and the automatic / manual signal acquisition unit is connected to the switch input end of the PLC controller U1; the output end of the PLC controller U1 is connected to the energy storage control circuit and the closing control circuit, the energy storage control circuit and the closing control circuit send energy storage signals and closing signals to the output terminals, and the output terminals 15, 17 are connected to the incoming circuit breaker QF.

[0023] The three-phase power supply acquisition unit is used to collect whether there is an electrical signal in the three-phase power supply, and at the same time, collect whether there is a phase loss signal in the three-phase power supply. The input end of the three-phase power supply acquisition unit is connected to the power supply terminals 1, 3, and 5, so as to collect the power supply signal through the power supply terminals 1, 3, and 5. The signal output end of the three-phase power supply acquisition unit is connected to the switch input terminals X1, X2, and X3 of the PLC controller U1.

[0024] The three-phase power supply acquisition unit includes three acquisition intermediate relays. The power terminals 1, 3, and 5 are respectively connected to the first ends of the three acquisition intermediate relay coils. The three acquisition intermediate relays are respectively the first acquisition intermediate relay KA1, the second acquisition intermediate relay KA2, and the third acquisition intermediate relay KA3. The second ends of the three acquisition intermediate relay coils are connected to the neutral line, the first ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the switch signal input terminals X1, X2, and X3 of the PLC controller U1, and the second ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the common terminals.

[0025] When the three-phase power supply is energized, the coils of the three acquisition intermediate relays are energized, and the normally open contacts of the three acquisition intermediate relays are closed, thereby transmitting the power-on signal to the PLC controller U1. When the normally open contact of any acquisition intermediate relay is not closed, it means that there is a phase loss signal. In this case, no closing signal can be given.

[0026] The automatic / manual signal acquisition unit is connected to the automatic / manual signal terminals 9 and 10 to acquire automatic signals and manual signals, thereby giving the signals to the PLC controller U1. The automatic / manual signal acquisition unit is connected to the switch input terminals X4 and X5 of the PLC controller U1.

[0027] The automatic / manual signal acquisition unit includes a manual button SB1 and an automatic button SB2; one end of the manual button SB1 / automatic button SB2 is connected to the power module, and the other end is connected to the neutral line N through the coil of the first intermediate relay KA4 / second intermediate relay KA5. One end of the normally open contact of the first intermediate relay KA4 / second intermediate relay KA5 is connected to the automatic / manual signal terminal 9, 10, and the automatic / manual signal terminal 9, 10 transmits the signal to the switch signal input end of the PLC controller U1. The second end of the normally open contact of the first intermediate relay KA4 / second intermediate relay KA5 is connected to the common end respectively. After the manual button SB1 is pressed, the coil of the first intermediate relay KA4 is energized, and the normally open contact of the first intermediate relay KA4 is actuated, thereby transmitting the manual signal to the PLC controller U1; the same applies to the automatic control signal.

[0028] In order to avoid the simultaneous appearance of automatic signals and manual signals, which would cause misoperation, the normally closed contact of the second intermediate relay KA5 is connected between the coil of the first intermediate relay KA4 and the neutral line N; the normally closed contact of the first intermediate relay KA4 is connected between the coil of the second intermediate relay KA5 and the neutral line N; thereby, the first intermediate relay KA4 and the second intermediate relay KA5 are interlocked, ensuring that the two cannot operate at the same time.

[0029] The output end of the PLC controller U1 is connected to an energy storage control circuit and a closing control circuit; an energy storage signal and a closing signal are output to the output terminal through the energy storage control circuit and the closing control circuit.

[0030] Among them, the energy storage control circuit includes an energy storage relay KA6, and the closing control circuit includes a closing relay KA7. The output end of the PLC controller U1 is connected to the coil of the energy storage relay KA6 and the coil of the closing relay KA7. The normally open contacts of the energy storage relay KA6 and the normally open contacts of the closing relay KA7 are used to be connected to the incoming circuit breaker QF, so that the energy storage switch signal and the closing switch signal can be transmitted to the incoming circuit breaker QF. After the energy storage switch signal is given to the incoming circuit breaker QF, the spring of the incoming circuit breaker QF stores energy, and the incoming circuit breaker QF is closed after the closing switch signal is given to the incoming circuit breaker QF. In this embodiment, after the coil of the closing relay KA7 is energized, the normally open contact of the closing relay KA7 is closed, and a closing signal can be sent to the incoming circuit breaker QF. As for how the incoming circuit breaker QF acts after receiving the closing signal, it is not within the scope of improvement of this application, and the action of the incoming circuit breaker QF after receiving the closing signal is a mature prior art, which is recorded in many existing schemes.

[0031] After the coil of the energy storage relay KA6 is energized, the normally open contacts of the energy storage relay KA6 are closed, and an energy storage signal can be sent to the incoming circuit breaker QF. As for how the incoming circuit breaker QF acts after receiving the energy storage signal, it is not within the scope of improvement of this application.

[0032] The working process is as follows: the three-phase power acquisition unit collects three-phase power information, and transmits the collected three-phase power voltage and phase loss signal to the PLC controller U1; when the power is off, the voltage signal collected by the three-phase power acquisition unit is zero, and the PLC controller U1 does not send a closing signal. When the power supply is restored, it detects whether there is a phase loss and whether it is an automatic operation. If normal, after a delay of 3S, it outputs an energy storage signal and maintains the time T1 (adjustable according to on-site conditions); if there is a phase loss, the execution process is stopped.

[0033] After the holding time delay is expired, the energy storage signal stops outputting, and the staggered closing delay T2 (adjustable according to on-site conditions) is performed; D) After the staggered closing delay is expired, the closing signal is outputted and the holding time T3 (adjustable according to on-site conditions) is performed; E) After the incoming circuit breaker QF is successfully closed, the power supply of the switching module is disconnected through the linkage closing point, the switching module loses power, and the execution is completed.

[0034] The delay time of this switching module can be freely set, with a time range of 0~9999 seconds; the power module life can reach 16,000 hours, and the power consumption is extremely small; the degree of integration is high, and the size can be very small, 88mmX107mmX59mm, suitable for various switch cabinet types, convenient and fast, and highly versatile.

[0035] As an alternative to this embodiment, in order to set the delay time, a touch screen is connected to the PLC controller U1, and the delay time is set through the touch screen, and the set time is displayed on the touch screen. The connection between the PLC controller U1 and the touch screen is a mature existing technology, so it will not be described in detail.

[0036] Among them, the energy storage signal holding time T1 is set as follows:

[0037] ①Press the "Set" button on the touch screen and hold it for 0.1S to enter the time setting interface, and SET1 is displayed;

[0038] ② At this time, press the "+" key and hold it for 0.1S, and the selected digit value will increase by 1;

[0039] ③Press the "Save" button and hold it for 0.1S to save the set T1 value and return to the time setting interface;

[0040] ④Press the “Save” button again and hold it for 0.1S to save all values ​​and return to the operation interface.

[0041] Setting of staggered closing delay time T2:

[0042] ①Press the "Set" key and hold it for 0.1S to enter the time setting interface, and SET1 is displayed;

[0043] ② At this time, press the "+" key and hold it for 0.1S, and the selected digit value will increase by 1;

[0044] ③Press the "Save" button and hold it for 0.1S to save the set T1 value and return to the time setting interface;

[0045] ④Press the “Save” button again and hold it for 0.1S to save all values ​​and return to the operation interface.

[0046] Embodiment 2, this embodiment is different from embodiment 1 in that, Figure 3 As shown, the power distribution cabinet incoming power automatic switching system also includes a host U2, and the number of automatic switching modules is multiple. The PLC controller U1 (model FX5u-32MR) of each automatic switching module communicates with the host. One automatic switching module is set in each power distribution cabinet in an area, and the delay time of different automatic switching modules is set through the host. At the same time, the host can also collect action commands of different automatic switching modules.

[0047] The communication method between the PLC controller U1 and the host is that the PLC controller U1 communicates with the host through Ethernet; the PLC controller U1 is connected to a first wireless communication terminal U4 (model DTD419M), and the host is connected to a second wireless communication terminal U3 (model DTD419M). The PLC controller U1 and the host communicate wirelessly through the first wireless communication terminal U4 and the second wireless communication terminal U3. The RJ45 interface of the first wireless communication terminal U4 and the RJ45 interface of the PLC controller U1 can be connected through a communication line. In this embodiment, the host can be the master PLC controller U1. By setting the master and slave machines, one host can receive signals from multiple PLC controllers U1, and can also send signals to multiple PLC controllers U1.

[0048] When there are multiple distribution cabinets in the same community, in order to avoid damage to the power grid caused by the simultaneous power supply of multiple distribution cabinets, a switching module is set in each distribution cabinet. The host sends a signal to the PLC controller U1 of each switching module, and sets a delay time for the output closing time of each PLC controller U1 to achieve staggered power supply.

[0049] For example: Distribution station No. 1 delays 6S to send out a closing signal; distribution station No. 2 delays 9S to send out a closing signal; distribution station No. 3 delays 12S to send out a closing signal, and so on... The specific time interval can be adjusted according to the specific situation on site.

[0050] The automatic switching system of the power distribution cabinet can collect the signals of three-phase electricity and whether there is a phase loss signal. It will automatically execute the closing function after the delay time set by the incoming call signal is reached. It can solve the time efficiency problem of manual closing and save users a lot of inefficient labor costs. At the same time, after the closing is completed, the system automatically cuts off the power, which improves energy consumption.

Claims

1. The power distribution cabinet has an incoming power automatic switching system, and the three-phase power is connected to an incoming circuit breaker, which is characterized by: It includes an automatic transfer module, which includes a shell, in which a power module, a PLC controller, and a three-phase power acquisition unit are arranged; The housing is provided with wiring terminals, which include power terminals, output terminals and automatic / manual signal terminals; The power terminal is connected to three-phase electricity, the three-phase power acquisition unit is connected to the power terminal, and the signal output end of the three-phase power acquisition unit is connected to the switch input end of the PLC controller; The automatic / manual signal terminal is connected with an automatic / manual signal acquisition unit, and the automatic / manual signal acquisition unit is connected to the switch input terminal of the PLC controller; The output end of the PLC controller is connected to an energy storage control circuit and a closing control circuit. The energy storage control circuit and the closing control circuit send energy storage signals and closing signals to the output terminals, and the output terminals are connected to the incoming circuit breaker.

2. The power distribution cabinet automatic power supply system according to claim 1, characterized in that: The incoming circuit breaker includes a normally open contact and a normally closed contact; the three-phase electricity L1, L2, and L3 are respectively connected to the A, B, and C phases of the incoming circuit breaker; the normally closed contact of the incoming circuit breaker is connected between the power supply module and the power supply terminal of the PLC controller.

3. The power distribution cabinet automatic power supply system according to claim 2, characterized in that: The three-phase power supply acquisition unit includes three acquisition intermediate relays. The three-phase electricity is respectively connected to the first ends of the three acquisition intermediate relay coils, the second ends of the three acquisition intermediate relay coils are connected to the neutral line, the first ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the switch signal input end of the PLC controller, and the second ends of the normally open contacts of the three acquisition intermediate relays are respectively connected to the common end.

4. The power distribution cabinet automatic power supply system according to claim 3, characterized in that: The automatic / manual signal acquisition unit includes a manual button and an automatic button; one end of the manual button / automatic button is connected to the power module, and the other end is connected to the neutral line through the coil of the first intermediate relay / second intermediate relay, one end of the normally open contact of the first intermediate relay / second intermediate relay is connected to the switch signal input end of the PLC controller, and the second end of the normally open contact of the first intermediate relay / second intermediate relay is connected to the common end respectively.

5. The power distribution cabinet automatic power supply system according to claim 4, characterized in that: The normally closed contact of the second intermediate relay is connected between the coil of the first intermediate relay and the neutral line; the normally closed contact of the first intermediate relay is connected between the coil of the second intermediate relay and the neutral line.

6. The power distribution cabinet automatic power supply system according to claim 5, characterized in that: The energy storage control circuit includes an energy storage relay, and the closing control circuit includes a closing relay. The output end of the PLC controller is connected to the coil of the energy storage relay and the coil of the closing relay.

7. The power distribution cabinet automatic power supply system according to claim 6, characterized in that: It also includes a host computer, and there are multiple automatic modules. The PLC controller of each automatic module communicates with the host computer.

8. The power distribution cabinet automatic power supply system according to claim 7, characterized in that: The PLC controller communicates with the host via Ethernet; a first wireless communication terminal is connected to the PLC controller, and a second wireless communication terminal is connected to the host. The PLC controller and the host communicate wirelessly via the first wireless communication terminal and the second wireless communication terminal.

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