PLC-based high-voltage side backup power source automatic switching device and automatic switching method thereof

Abstract

The application discloses a high-voltage side spare power automatic switching device based on PLC and an automatic switching method thereof, and the automatic switching device comprises a PLC, a first bus, a second bus, a third bus, a first plant internal power supply incoming line, a second plant internal power supply incoming line, a third plant internal power supply incoming line, a fourth plant internal power supply incoming line, a fifth external power supply incoming line, a first incoming line switch, a second incoming line switch, a third incoming line switch, a fourth incoming line switch, a fifth incoming line switch, a first bus coupler switch and a second bus coupler switch, wherein the first plant internal power supply incoming line and the second plant internal power supply incoming line are connected with the first bus respectively, the third plant internal power supply incoming line and the fourth plant internal power supply incoming line are connected with the third bus respectively, the fifth external power supply incoming line is connected with the second bus, each incoming line switch is arranged on each power supply incoming line, and the bus coupler switch is arranged between the buses. The automatic switching device and the automatic switching method thereof have high stability, can reliably switch between operation modes, and have simple automatic switching lines and high automatic switching efficiency.

Description

Technical Field

[0001] This invention belongs to the field of automatic backup power supply technology, specifically, it relates to a PLC-based high-voltage side automatic backup power supply device and its automatic switching method. Background Technology

[0002] As production and daily life become increasingly modernized, people's demand for and reliance on electricity are also increasing, and their requirements for power quality are becoming more stringent. Power supply and distribution in various fields are constantly moving towards automation, unmanned operation, remote control, and uninterrupted power supply. Some power users, in particular, have a more prominent requirement for uninterrupted power supply, especially during peak electricity consumption periods when power shortages are severe. As a result, many large enterprises have built their own power plants or equipped themselves with generators. Therefore, the switching between various power sources and ensuring uninterrupted and highly reliable power supply have become important parts of the protection and control circuits in modern power distribution engineering.

[0003] The configuration of backup power supplies on the high-voltage side of power plants and the setting of automatic transfer switches for backup power supplies are particularly important. However, the backup power automatic transfer switches used in some power plants currently employ the traditional direct mechanical relay control mode, which results in low stability during power switching, posing certain safety hazards to the stable operation of the power system. At the same time, with the increase of various electrical equipment, the power supply also needs to adapt to various operating modes. However, the current backup power automatic transfer switches cannot adapt well to various operating modes, resulting in complex automatic transfer circuits and low automatic transfer efficiency during the setting of operating modes. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings in the prior art, the present invention provides a PLC-based high-voltage side backup power automatic transfer device and its automatic transfer method, which has high stability, reliable switching between multiple operating modes, simple automatic transfer circuit, and high automatic transfer efficiency.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A PLC-based high-voltage side backup power automatic transfer device includes a PLC as the core of the automatic transfer control, and a first busbar, a second busbar, a third busbar, a first internal power supply line, a second internal power supply line, a third internal power supply line, a fourth internal power supply line, a fifth external power supply line, a first incoming line switch, a second incoming line switch, a third incoming line switch, a fourth incoming line switch, a fifth incoming line switch, a first bus tie switch, and a second bus tie switch, all connected to the PLC. The first internal power supply line and the second internal power supply line are respectively connected to the first busbar, and the third internal power supply line and the fourth internal power supply line are respectively connected to the third busbar. The fifth external power supply line is connected to the second busbar. The first, second, third, fourth, and fifth power supply switches are respectively installed on the first, second, third, fourth, and fifth internal power supply lines. The first and second busbars are connected through the first bus tie switch, and the second and third busbars are connected through the second bus tie switch. The first, second, third, fourth, and fifth power supply switches, the first bus tie switch, and the second bus tie switch are all closing interlocking switches.

[0007] Furthermore, the PLC includes a PLC processor, and a switch status acquisition unit, voltage transmitter, current transmitter, output relay, color touch screen, alarm buzzer, power supply unit, and power surge protector, all connected to the PLC processor. The first, second, third, fourth, and fifth incoming line switches, the first bus tie switch, and the second bus tie switch are all connected to the switch status acquisition unit. The first bus, second bus, third bus, first internal power supply line, and second... The factory power supply line, the third factory power supply line, the fourth factory power supply line, and the fifth external power supply line are all connected to the voltage transmitter. The first busbar, the second busbar, the third busbar, the first factory power supply line, the second factory power supply line, the third factory power supply line, the fourth factory power supply line, and the fifth external power supply line are all connected to the current transmitter. The first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch are all connected to the output relay.

[0008] Furthermore, the PLC processor (601) uses a controller of model M580.

[0009] Furthermore, the PLC is equipped with a moisture-proof heater.

[0010] Based on the above system structure, the present invention also provides a method for automatic transfer of a high-voltage side backup power supply automatic transfer device based on a PLC, comprising the following steps:

[0011] S1: According to the automatic transfer logic of the incoming power lines between the first, second, third, fourth, and fifth external power lines, as well as the segmented automatic transfer logic between the first, second, and third busbars, the automatic transfer logic is divided into nine operating modes and preset in the PLC. The closing interlocking conditions are set according to the automatic transfer logic and preset in the PLC.

[0012] S2: The PLC collects the voltage and current information of the first busbar, second busbar, third busbar, first internal power supply line, second internal power supply line, third internal power supply line, fourth internal power supply line, and fifth external power supply line. The PLC also collects the switch status of the first incoming switch, second incoming switch, third incoming switch, fourth incoming switch, fifth incoming switch, first bus tie switch, and second bus tie switch to determine the current operating status and use the current operating status as the start condition for automatic transfer.

[0013] S3: Based on the determined operating status and start-up conditions, under the control of the PLC, the first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch perform corresponding tripping or closing automatic transfer actions.

[0014] S4: According to the closing interlocking conditions, the first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch are respectively closed and interlocked.

[0015] Furthermore, in step S1, the nine operating modes are as follows:

[0016] Method 1: The first and third incoming line switches are closed, the second, fourth, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0017] Method 2: The first and fourth incoming line switches are closed, the second, third, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0018] Method 3: The second and third incoming line switches are closed, the first, fourth, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0019] Method 4: The second and fourth incoming line switches are closed, the first, third, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0020] Method 5: The first incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the second incoming line switch, the third incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0021] Method 6: The second incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the third incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0022] Method 7: The third incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the second incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0023] Method 8: The fourth incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fifth incoming line switch are open.

[0024] Method 9: The fifth incoming line switch, the first bus tie switch, and the second bus tie switch are closed, while the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fourth incoming line switch are open.

[0025] Furthermore, in step S2, the voltage and current information of the corresponding first incoming power switch, second incoming power switch, third incoming power switch, fourth incoming power switch, and fifth incoming power switch are determined by using the voltage and current information of the first internal power supply line, second internal power supply line, third internal power supply line, fourth internal power supply line, and fifth external power supply line.

[0026] Furthermore, in step S3, the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fourth incoming line switch confirm that the switch trips because the switch is in the open position and the corresponding incoming line has no voltage and no current.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) Based on a PLC and the first bus, second bus, third bus, first internal power supply line, second internal power supply line, third internal power supply line, fourth internal power supply line, fifth external power supply line, first incoming line switch, second incoming line switch, third incoming line switch, fourth incoming line switch, fifth incoming line switch, first bus tie switch, and second bus tie switch, all connected to the PLC, a high-voltage side backup power automatic transfer device is constructed. The entire device not only realizes reliable switching of nine operating modes on the power consumption side, but also has high stability. Due to centralized detection and control by the PLC, the automatic transfer device has a simple connection line and high automatic transfer efficiency.

[0029] (2) The PLC of this invention includes a PLC processor, and a switch status acquisition unit, a voltage transmitter, a current transmitter, an output relay, a color touch screen, an alarm buzzer, a power supply unit, and a power surge protector, all of which are connected to the PLC processor. The entire PLC structure is simple. The switch status acquisition unit, voltage transmitter, and current transmitter realize the detection function. The output relay realizes the automatic transfer execution function. The color touch screen realizes a visual human-machine interface, which is convenient for displaying the real-time operating status and setting the device parameters. The power supply unit provides a stable power supply to the PLC. In addition, by setting an alarm buzzer on the PLC, the user can be effectively reminded during the automatic transfer operation. By setting a power surge protector on the PLC, the stable operation of the PLC is ensured. The entire automatic transfer device not only realizes the automatic transfer function, but also has a very simple connection circuit.

[0030] (3) The PLC processor of this invention adopts Schneider M580 controller product, and a moisture-proof heater is provided on the PLC to ensure the stable operation of the PLC and further enhance the stability of the entire automatic switching device.

[0031] (4) According to the incoming line automatic transfer logic and the bus automatic transfer logic, the automatic transfer logic is divided into nine operating modes, and the closing interlocking conditions are set according to the automatic transfer logic. The PLC collects information, judges the current operating status, and uses the current operating status as the starting condition for automatic transfer. According to the judged operating status and starting condition, the automatic transfer device makes the corresponding tripping or closing automatic transfer action. According to the closing interlocking conditions, each incoming line switch and bus tie switch is closed interlocked to avoid the occurrence of switch malfunction. The entire automatic transfer method not only realizes automatic transfer of multiple operating modes, but also has high stability under the centralized control of PLC.

[0032] (5) This invention uses the voltage and current information in the power supply line to determine the voltage and current information in the corresponding switch. By setting the confirmation switch trip logic to the switch being in the open position and the corresponding power supply line having no voltage and no current, the stability of the automatic transfer is ensured. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the self-dispensing device of the present invention.

[0034] Figure 2 This is a schematic diagram of the power supply side wiring of the automatic transfer device of the present invention.

[0035] Figure 3 This is a flowchart of the self-feeding method of the present invention.

[0036] Figure 4 This is a schematic diagram of the closing and locking conditions of the first incoming switch of the present invention.

[0037] Figure 5 This is a schematic diagram of the closing and locking conditions of the second incoming line switch of the present invention.

[0038] Figure 6 This is a schematic diagram of the closing and locking conditions of the third incoming switch of the present invention.

[0039] Figure 7 This is a schematic diagram of the closing and locking conditions of the fourth incoming line switch of the present invention.

[0040] Figure 8 This is a schematic diagram of the closing and locking conditions for the fifth incoming line switch of the present invention.

[0041] Figure 9 This is a schematic diagram of the closing interlocking conditions for the first bus tie switch of the present invention.

[0042] Figure 10 This is a schematic diagram of the closing interlocking conditions for the second bus tie switch of the present invention.

[0043] In the above figures, the component names corresponding to the reference numerals are as follows:

[0044] 1-First internal power supply line, 2-Second internal power supply line, 3-Third internal power supply line, 4-Fourth internal power supply line, 5-Fifth external power supply line, 6-PLC, 601-PLC processor, 602-Switch status acquisition unit, 603-Voltage transmitter, 604-Current transmitter, 605-Output relay, 606-Moisture-proof heater, 607-Color touch screen, 608-Alarm buzzer, 609-Power supply unit, 610-Power surge protector, 7-First busbar, 8-Second busbar, 9-Third busbar, 101-First incoming switch, 102-Second incoming switch, 103-Third incoming switch, 104-Fourth incoming switch, 105-Fifth incoming switch, 107-First bus tie switch, 108-Second bus tie switch. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0046] Example

[0047] like Figures 1 to 2 As shown, this embodiment provides a PLC-based high-voltage side backup power automatic transfer device, including a PLC 6, a first busbar 7, a second busbar 8, a third busbar 9, a first internal power supply line 1, a second internal power supply line 2, a third internal power supply line 3, a fourth internal power supply line 4, a fifth external power supply line 5, a first incoming line switch 101, a second incoming line switch 102, a third incoming line switch 103, a fourth incoming line switch 104, a fifth incoming line switch 105, a first bus tie switch 107, and a second bus tie switch 108. The PLC is a programmable logic controller, a digital computing controller with a microprocessor used for automated control. It can load control instructions into memory for storage and execution at any time. PLC is an abbreviation for Programmable Logic Controller. PLCs are widely used in various working environments and have a very wide range of applications. This embodiment uses the PLC as the core of the automatic transfer control, providing stable control of the automatic transfer device and realizing automatic transfer functions in multiple operating modes.

[0048] In this embodiment, the first, second, third, fourth, and fifth external power supply lines are connected via a first, second, third, fourth, and fifth incoming power switch, respectively, to form an automatic transfer switch. The first, second, and third busbars are connected via a first and second bus tie switch, respectively, to form an automatic busbar transfer switch. The automatic transfer switches in various operating modes are centrally detected and controlled by a PLC. In this embodiment, by setting up three busbars, more electrical equipment can be flexibly installed, and various operating modes can be formed accordingly. Of the three busbars, two are powered by the plant's internal power supply, and one is powered by the external power supply.

[0049] In this embodiment, the PLC includes a PLC processor 601, and a switch status acquisition unit 602, a voltage transmitter 603, a current transmitter 604, an output relay 605, a color touch screen 607, an alarm buzzer 608, a power supply unit 609, and a power surge protector 610, all connected to the PLC processor. The entire PLC structure is simple. The switch status acquisition unit, voltage transmitter, and current transmitter realize the detection function. The output relay realizes the automatic transfer execution function. The color touch screen realizes a visual human-machine interface, which is convenient for displaying real-time operating status and setting device parameters. The power supply unit provides a stable power supply to the PLC. In addition, by setting an alarm buzzer on the PLC, the user can be effectively reminded during the automatic transfer action. By setting a power surge protector on the PLC, the stable operation of the PLC is ensured. The entire automatic transfer device not only realizes the automatic transfer function, but also has a very simple connection circuit. Meanwhile, in this embodiment, the PLC processor adopts the Schneider M580 controller product, and a moisture-proof heater 606 is provided on the PLC to ensure the stable operation of the PLC and further enhance the stability of the entire automatic transfer device. In this embodiment, the moisture-proof heater, power surge protector, and alarm buzzer are all connected to the PLC processor.

[0050] like Figures 3 to 10 As shown, this embodiment also provides an automatic transfer method for a PLC-based high-voltage side backup power supply automatic transfer device, including the following steps:

[0051] S1: According to the automatic transfer logic of the incoming power lines between the first, second, third, fourth, and fifth external power lines, as well as the segmented automatic transfer logic between the first, second, and third busbars, the automatic transfer logic is divided into nine operating modes and preset in the PLC. The closing interlocking conditions are set according to the automatic transfer logic and preset in the PLC.

[0052] S2: The PLC collects the voltage and current information of the first busbar, second busbar, third busbar, first internal power supply line, second internal power supply line, third internal power supply line, fourth internal power supply line, and fifth external power supply line. The PLC also collects the switch status of the first incoming switch, second incoming switch, third incoming switch, fourth incoming switch, fifth incoming switch, first bus tie switch, and second bus tie switch to determine the current operating status and use the current operating status as the start condition for automatic transfer.

[0053] S3: Based on the determined operating status and start-up conditions, under the control of the PLC, the first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch perform corresponding tripping or closing automatic transfer actions.

[0054] S4: According to the closing interlocking conditions, the first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch are respectively closed and interlocked.

[0055] In this embodiment, the automatic transfer logic is divided into nine operating modes according to the incoming line automatic transfer logic and the bus automatic transfer logic. Closing interlocking conditions are set according to the automatic transfer logic. The PLC collects information, judges the current operating status, and uses the current operating status as the start condition for automatic transfer. According to the judged operating status and start condition, the automatic transfer device performs the corresponding tripping or closing automatic transfer action. According to the closing interlocking condition, each incoming line switch and bus tie switch is closed and interlocked respectively. The entire automatic transfer method not only realizes automatic transfer in multiple operating modes, but also has high stability under the centralized control of PLC.

[0056] In this embodiment, the nine operating modes in step S1 are as follows:

[0057] Method 1: The first and third incoming line switches are closed, the second, fourth, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0058] Method 2: The first and fourth incoming line switches are closed, the second, third, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0059] Method 3: The second and third incoming line switches are closed, the first, fourth, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0060] Method 4: The second and fourth incoming line switches are closed, the first, third, and fifth incoming line switches are open, and only one of the first and second bus tie switches is open;

[0061] Method 5: The first incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the second incoming line switch, the third incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0062] Method 6: The second incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the third incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0063] Method 7: The third incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the second incoming line switch, the fourth incoming line switch, and the fifth incoming line switch are open.

[0064] Method 8: The fourth incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fifth incoming line switch are open.

[0065] Method 9: The fifth incoming line switch, the first bus tie switch, and the second bus tie switch are closed, while the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fourth incoming line switch are open.

[0066] In this embodiment, the start conditions and automatic switching actions for each operating mode are as follows in steps S2 and S3:

[0067] Method 1:

[0068] The conditions for starting Method 1 include:

[0069] Start-up condition 1: The first busbar is de-energized, the first incoming switch is de-energized and de-energized, and the third busbar is energized;

[0070] Start-up condition two: The third busbar is de-energized, the third incoming switch has no current and no voltage, and the first busbar is energized;

[0071] Start-up condition three: The first busbar and the third busbar are both de-energized, the first incoming switch and the third incoming switch are both de-energized and de-energized, and the fifth incoming switch is energized.

[0072] If the first activation condition is met, the high-voltage side backup power automatic transfer device will trip the first incoming line switch. After confirming that the first incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0073] If the second start-up condition is met, the high-voltage side backup power automatic transfer device will trip the third incoming line switch. After confirming that the third incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an action signal will be sent.

[0074] If the third starting condition is met, the high-voltage side backup power automatic transfer device will trip the first and third incoming line switches. After confirming that the first and third incoming line switches have tripped, the first bus tie switch and the second bus tie switch will be closed first. Then the device will determine whether the fifth incoming line switch has voltage. If the fifth incoming line switch has voltage, the fifth incoming line switch will be closed after a delay, and an alarm will be triggered and an action signal will be sent.

[0075] Method 2:

[0076] The conditions for starting Method 2 include:

[0077] Start-up condition 1: The first busbar is de-energized, the first incoming switch is de-energized and de-energized, and the third busbar is energized;

[0078] Start-up condition two: The third busbar is de-energized, the fourth incoming switch has no current and no voltage, and the first busbar is energized.

[0079] Start-up condition three: The first busbar and the third busbar are both de-energized, the first incoming switch and the fourth incoming switch are both de-energized and de-energized, and the fifth incoming switch is energized.

[0080] If the first activation condition is met, the high-voltage side backup power automatic transfer device will trip the first incoming line switch. After confirming that the first incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0081] If the second activation condition is met, the high-voltage side backup power automatic transfer device will trip the fourth incoming line switch. After confirming that the fourth incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0082] If the third starting condition is met, the high-voltage side backup power automatic transfer device will trip the first and fourth incoming line switches. After confirming that the first and fourth incoming line switches have tripped, the first bus tie switch and the second bus tie switch will be closed first. Then the device will determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the fifth incoming line switch will be closed after a delay, and an alarm will be triggered and an action signal will be sent.

[0083] Method 3:

[0084] The conditions for starting Method 3 include:

[0085] Start-up condition 1: The first busbar is de-energized, the second incoming switch is de-energized and has no current, and the third busbar is energized;

[0086] Start-up condition two: The third busbar is de-energized, the third incoming switch has no current and no voltage, and the first busbar is energized.

[0087] Start-up condition three: The first and third busbars are both de-energized, the second and third incoming line switches are both de-energized and de-energized, and the fifth incoming line switch is energized.

[0088] If the first activation condition is met, the high-voltage side backup power automatic transfer device will trip the second incoming line switch. After confirming that the second incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0089] If the second start-up condition is met, the high-voltage side backup power automatic transfer device will trip the third incoming line switch. After confirming that the third incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an action signal will be sent.

[0090] If the third starting condition is met, the high-voltage side backup power automatic transfer device will trip the second and third incoming line switches. After confirming that the second and third incoming line switches have tripped, the first and second bus tie switches will be closed first. Then the device will determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the fifth incoming line switch will be closed after a delay, and an alarm will be triggered and an action signal will be sent.

[0091] Method 4:

[0092] The conditions for starting Method 4 include:

[0093] Start-up condition 1: The first busbar is de-energized, the second incoming switch is de-energized and has no current, and the third busbar is energized;

[0094] Start-up condition two: The third busbar is de-energized, the fourth incoming switch has no current and no voltage, and the first busbar is energized.

[0095] Start-up condition three: The first and third busbars are both de-energized, the second and fourth incoming switches are both de-energized and de-energized, and the fifth incoming switch is energized.

[0096] If the first activation condition is met, the high-voltage side backup power automatic transfer device will trip the second incoming line switch. After confirming that the second incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0097] If the second activation condition is met, the high-voltage side backup power automatic transfer device will trip the fourth incoming line switch. After confirming that the fourth incoming line switch has tripped, the first bus tie switch and the second bus tie switch will be closed, and an alarm will be triggered and an activation signal will be sent.

[0098] If the third starting condition is met, the high-voltage side backup power automatic transfer device will trip the second and fourth incoming line switches. After confirming that the second and fourth incoming line switches have tripped, the first and second bus tie switches will be closed first. Then the device will determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the fifth incoming line switch will be closed after a delay, and an alarm will be triggered and an action signal will be sent.

[0099] Method 5:

[0100] The starting conditions for Mode 5 are: both the first and third busbars are de-energized, the first incoming switch has no current and no voltage, and the fifth incoming switch has voltage.

[0101] If the start-up conditions are met, the high-voltage side backup power automatic transfer device will trip the first incoming line switch. After confirming that the first incoming line switch has tripped, the device will then determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the device will close the fifth incoming line switch, and at the same time, an alarm will be triggered and an action signal will be sent.

[0102] Method Six:

[0103] The starting conditions for Mode 6 are: no voltage on the first busbar and the third busbar, no current and no voltage on the second incoming switch, and voltage on the fifth incoming switch;

[0104] If the start-up conditions are met, the high-voltage side backup power automatic transfer device will trip the second incoming line switch. After confirming that the second incoming line switch has tripped, the device will then determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the device will close the fifth incoming line switch, and at the same time, an alarm will be triggered and an action signal will be sent.

[0105] Method Seven:

[0106] The conditions for starting mode seven are: no voltage on the first busbar and the third busbar, no current and no voltage on the third incoming switch, and voltage on the fifth incoming switch;

[0107] If the start-up conditions are met, the high-voltage side backup power automatic transfer device will trip the third incoming line switch. After confirming that the third incoming line switch has tripped, the device will then determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the device will close the fifth incoming line switch, and at the same time, an alarm will be triggered and an action signal will be sent.

[0108] Method 8:

[0109] The conditions for starting mode 8 are: no voltage on the first busbar and the third busbar, no current and no voltage on the fourth incoming switch, and voltage on the fifth incoming switch;

[0110] If the start-up conditions are met, the high-voltage side backup power automatic transfer device will trip the fourth incoming line switch. After confirming that the fourth incoming line switch has tripped, the device will then determine whether the fifth incoming line switch is under pressure. If the fifth incoming line switch is under pressure, the device will close the fifth incoming line switch, and at the same time, an alarm will be triggered and an action signal will be sent.

[0111] Method Nine:

[0112] The fifth incoming line switch, the first bus tie switch, and the second bus tie switch are closed; the first incoming line switch, the second incoming line switch, the third incoming line switch, and the fourth incoming line switch are open; the first bus and the third bus are energized; and the fifth incoming line switch is energized. The operating logic is currently only for monitoring.

[0113] In this embodiment, the closing interlocking conditions for the first incoming line switch, the second incoming line switch, the third incoming line switch, the fourth incoming line switch, the fifth incoming line switch, the first bus tie switch, and the second bus tie switch are as follows:

[0114] Conditions for closing the first incoming line switch

[0115] Permitted closing method one: the second, third, fourth, and fifth incoming switches are all opened;

[0116] Permissible closing method two: the second incoming line switch, the fifth incoming line switch, and the second bus tie switch are all opened;

[0117] Permissible closing method three: Both the second incoming line switch and the first bus tie switch are open;

[0118] Conditions for closing the second incoming line switch

[0119] Permitted closing method one: the first incoming switch, the third incoming switch, the fourth incoming switch, and the fifth incoming switch are all opened;

[0120] Permissible closing method two: the first incoming line switch, the fifth incoming line switch, and the second bus tie switch are all opened;

[0121] Permissible closing method three: both the first incoming line switch and the first bus tie switch are open;

[0122] Third incoming line switch closing conditions

[0123] Permitted closing method one: the first incoming switch, the second incoming switch, the fourth incoming switch, and the fifth incoming switch are all opened;

[0124] Permissible closing method two: the fourth incoming switch, the fifth incoming switch, and the first bus tie switch are all opened;

[0125] Permissible closing method three: both the fourth incoming line switch and the second bus tie switch are open;

[0126] Closing conditions for the fourth incoming line switch

[0127] Permitted closing method one: the first incoming switch, the second incoming switch, the third incoming switch, and the fifth incoming switch are all opened;

[0128] Permissible closing method two: the third incoming line switch, the fifth incoming line switch, and the first bus tie switch are all opened;

[0129] Permissible closing method three: both the third incoming line switch and the second bus tie switch are open;

[0130] Closing conditions of the fifth incoming line switch

[0131] Permitted closing method 1: The first incoming switch, the second incoming switch, the third incoming switch, and the fourth incoming switch are all opened;

[0132] Permissible closing method two: the first incoming switch, the second incoming switch, and the second bus tie switch are all opened;

[0133] Permissible closing method three: the third incoming switch, the fourth incoming switch, and the first bus tie switch are all opened;

[0134] Permissible closing method four: Both the first bus tie switch and the second bus tie switch are open;

[0135] Conditions for closing the first bus tie switch

[0136] Permitted closing method 1: The first incoming switch, the second incoming switch, the third incoming switch, and the fourth incoming switch are all opened;

[0137] Permitted closing method two: the first incoming switch, the second incoming switch, and the fifth incoming switch are all opened;

[0138] Permissible closing method three: the first incoming switch, the second incoming switch, and the second bus tie switch are all opened;

[0139] Permitted closing method four: the third incoming switch, the fourth incoming switch, and the fifth incoming switch are all opened;

[0140] Permissible closing method five: Both the fifth incoming line switch and the second bus tie switch are open;

[0141] Conditions for closing the second bus tie switch

[0142] Permitted closing method 1: The first incoming switch, the second incoming switch, the third incoming switch, and the fourth incoming switch are all opened;

[0143] Permitted closing method two: the third incoming switch, the fourth incoming switch, and the fifth incoming switch are all opened;

[0144] Permissible closing method three: the third incoming switch, the fourth incoming switch, and the first bus tie switch are all opened;

[0145] Permissible closing method four: the first incoming switch, the second incoming switch, and the fifth incoming switch are all opened;

[0146] Permissible closing method five: Both the fifth incoming line switch and the first bus tie switch are open;

[0147] In this embodiment, the voltage and current information in the power input line are used to determine the voltage and current information in the corresponding switch. By setting the switch tripping logic to the open position and the corresponding input line having no voltage and no current, the stability of the automatic transfer is ensured.

[0148] In use, this invention constructs a high-voltage side backup power automatic transfer device based on a PLC and connected to the PLC via a first busbar, second busbar, third busbar, first internal power supply line, second internal power supply line, third internal power supply line, fourth internal power supply line, fifth external power supply line, first incoming line switch, second incoming line switch, third incoming line switch, fourth incoming line switch, fifth incoming line switch, first bus tie switch, and second bus tie switch. The entire device not only reliably switches between nine operating modes on the power consumption side but also exhibits high stability. Due to centralized detection and control via the PLC, the automatic transfer device has a simple connection circuit and high automatic transfer efficiency. In this embodiment, the connection between the PLC processor and the switch status acquisition unit, voltage transmitter, current transmitter, output relay, color touchscreen, power supply unit, moisture-proof heater, power surge protector, and alarm buzzer is existing technology and can be implemented through conventional hardware design; its specific circuit structure will not be described in detail in this embodiment.

[0149] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any changes made based on the design principles of the present invention, or any non-creative modifications made thereon, shall fall within the scope of protection of the present invention.

Claims

1. A PLC-based high-voltage side backup power automatic transfer device, characterized in that: The system includes a PLC (6) as the core of the automatic switching control, and a first busbar (7), a second busbar (8), a third busbar (9), a first internal power supply line (1), a second internal power supply line (2), a third internal power supply line (3), a fourth internal power supply line (4), a fifth external power supply line (5), a first incoming line switch (101), a second incoming line switch (102), a third incoming line switch (103), a fourth incoming line switch (104), a fifth incoming line switch (105), a first bus tie switch (107), and a second bus tie switch (108), wherein the first internal power supply line (1) and the second internal power supply line (2) are respectively connected to the first busbar (7), the third internal power supply line (3) and the fourth internal power supply line (4) are respectively connected to the third busbar (9), and the fifth external power supply line (5) is connected to the second busbar (9). The line (8) is connected, and the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), and the fifth incoming line switch (105) are respectively set on the first internal power supply line (1), the second internal power supply line (2), the third internal power supply line (3), the fourth internal power supply line (4), and the fifth external power supply line (5). The first bus (7) and the second bus (8) are connected through the first bus tie switch (107), and the second bus (8) and the third bus (9) are connected through the second bus tie switch (108). The first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), the fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) are all closing interlocking switches. The automatic transfer method of the PLC-based high-voltage side backup power supply automatic transfer device includes the following steps: S1: According to the automatic transfer logic of the incoming power lines between the first internal power line (1), the second internal power line (2), the third internal power line (3), the fourth internal power line (4), and the fifth external power line (5), and the segmented automatic transfer logic between the first bus (7), the second bus (8), and the third bus (9), the automatic transfer logic is divided into nine operating modes and preset in the PLC (6). The closing interlocking conditions are set according to the automatic transfer logic and preset in the PLC (6). S2: The voltage and current information of the first bus (7), the second bus (8), the third bus (9), the first power supply line (1), the second power supply line (2), the third power supply line (3), the fourth power supply line (4), and the fifth external power supply line (5) are collected by the PLC (6), and the switch status of the first incoming switch (101), the second incoming switch (102), the third incoming switch (103), the fourth incoming switch (104), the fifth incoming switch (105), the first bus tie switch (107), and the second bus tie switch (108) are collected by the PLC (6), the current operating status is determined, and the current operating status is used as the start condition for automatic transfer. S3: Based on the determined operating status and start-up conditions, under the control of PLC (6), the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), the fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) perform corresponding tripping or closing automatic transfer actions; S4: According to the closing interlocking conditions, the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), the fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) shall be closed interlocked respectively; In step S1, the nine operating modes are as follows: Method 1: The first incoming line switch (101) and the third incoming line switch (103) are closed, the second incoming line switch (102), the fourth incoming line switch (104), and the fifth incoming line switch (105) are open, and only one of the first bus tie switch (107) and the second bus tie switch (108) is open; Method 2: The first incoming line switch (101) and the fourth incoming line switch (104) are closed, the second incoming line switch (102), the third incoming line switch (103), and the fifth incoming line switch (105) are open, and only one of the first bus tie switch (107) and the second bus tie switch (108) is open; Method 3: The second incoming line switch (102) and the third incoming line switch (103) are closed, the first incoming line switch (101), the fourth incoming line switch (104), and the fifth incoming line switch (105) are open, and only one of the first bus tie switch (107) and the second bus tie switch (108) is open; Method 4: The second incoming line switch (102) and the fourth incoming line switch (104) are closed, the first incoming line switch (101), the third incoming line switch (103), and the fifth incoming line switch (105) are open, and only one of the first bus tie switch (107) and the second bus tie switch (108) is open; Method 5: The first incoming line switch (101), the first bus tie switch (107), and the second bus tie switch (108) are closed, while the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), and the fifth incoming line switch (105) are open; Method 6: The second incoming line switch (102), the first bus tie switch (107), and the second bus tie switch (108) are closed, while the first incoming line switch (101), the third incoming line switch (103), the fourth incoming line switch (104), and the fifth incoming line switch (105) are open; Method 7: The third incoming line switch (103), the first bus tie switch (107), and the second bus tie switch (108) are closed, while the first incoming line switch (101), the second incoming line switch (102), the fourth incoming line switch (104), and the fifth incoming line switch (105) are open; Method 8: The fourth incoming line switch (104), the first bus tie switch (107), and the second bus tie switch (108) are closed, while the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), and the fifth incoming line switch (105) are open; Method 9: The fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) are closed, while the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), and the fourth incoming line switch (104) are open.

2. The PLC-based high-voltage side backup power automatic transfer device according to claim 1, characterized in that: The PLC (6) includes a PLC processor (601), and a switch status acquisition unit (602), a voltage transmitter (603), a current transmitter (604), an output relay (605), a color touch screen (607), an alarm buzzer (608), a power supply unit (609), and a power surge protector (610), all connected to the PLC processor (601). The first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), the fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) are all connected to the switch status acquisition unit (602). The first bus (7), the second bus (8), the third bus (9), the first internal power supply line (1), the second internal power supply line (2), the third internal power supply line (3), the fourth internal power supply line (4), and the fifth external power supply line (5) are all connected to the voltage transmitter (603). The first busbar (7), the second busbar (8), the third busbar (9), the first internal power supply line (1), the second internal power supply line (2), the third internal power supply line (3), the fourth internal power supply line (4), and the fifth external power supply line (5) are all connected to the current transmitter (604). The first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), the fifth incoming line switch (105), the first bus tie switch (107), and the second bus tie switch (108) are all connected to the output relay (605).

3. The PLC-based high-voltage side backup power automatic transfer device according to claim 2, characterized in that: The PLC processor (601) uses a controller of model M580.

4. A PLC-based high-voltage side backup power automatic transfer device according to claim 2, characterized in that: The PLC (6) is equipped with a moisture-proof heater (606).

5. A PLC-based high-voltage side backup power automatic transfer device according to claim 1, characterized in that: In step S2, the voltage and current information of the first power supply line (1), the second power supply line (2), the third power supply line (3), the fourth power supply line (4), and the fifth external power supply line (5) are used to determine the voltage and current information of the corresponding first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), the fourth incoming line switch (104), and the fifth incoming line switch (105).

6. A PLC-based high-voltage side backup power automatic transfer device according to claim 1, characterized in that: In step S3, the first incoming line switch (101), the second incoming line switch (102), the third incoming line switch (103), and the fourth incoming line switch (104) confirm the switch trip logic as follows: the switch is in the open position and the corresponding incoming line has no voltage and no current.

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