CN117170218A - Stage mechanical switching control safety detection device and use method - Google Patents

Abstract

The invention belongs to the field of stage mechanical control, and discloses a stage mechanical switching control safety detection device and a use method thereof, wherein the device comprises a matrix switching circuit, a routing inspection judging circuit and a PLC (programmable logic controller) which participates in judgment and redundancy switching, and the matrix switching circuit is electrically connected with the routing inspection judging circuit; the inspection judging circuit comprises a plurality of frequency converters, a matrix switching gating and an inspection circuit, wherein the frequency converters are electrically connected and controlled by a PLC (programmable logic controller) through a communication network, the matrix switching gating and the inspection circuit are electrically connected, the PLC, the frequency converters and the matrix switching gating form a loop, and the switching failure of the matrix switching circuit and the failure diagnosis of the inspection judging circuit component are completed through the PLC; the PLC detects the state of the matrix switching circuit through the equipment signal power supply and the forced superposition signal which are electrically connected through the inspection scanning control, judges the fault state according to the state detection, adjusts the sequencing of the frequency converters, and carries out matrix switching and inspection judgment again. And safety detection and multiple redundancy automatic switching are realized.

Description

A stage machinery switching control safety detection device and its use method

Technical field

The invention belongs to the field of stage machinery control, and more specifically relates to a stage machinery switching control safety detection device and a method of use.

Background technique

In the field of stage machinery control systems, there are a large number of stage machinery switching control application requirements. Due to its low matrix switching control cost and high redundancy, it has a high application trend. Mainly used in some small theaters with low safety requirements and infrequent performances. At present, stage machinery matrix switching control adopts open-loop switching control, specifically 1. relay, contactor switching control, and PLC full matrix point output strobe (or decoding circuit) method. 2. Logic chip, relay and contactor switching control, PLC full output matrix point output strobe (or decoding circuit) mode. 3. Microcontroller (or FPGA) chip + relay + contactor mode, PLC full output matrix point output strobe (or decoding circuit) mode. The above method does not detect the switching result. Due to the large number of wiring and components in the stage machinery matrix switching control, there are potential safety hazards caused by wiring or component failures. The hidden dangers of mis-cutting and cross-cutting cannot be discovered in time, causing matrix switching circuit failures and lack of automatic redundant switching functions, affecting system reliability. Redundancy requires manual operation, low redundancy efficiency, and lack of effective detection, which affects its safety. Only the frequency converter is redundant, and the matrix switching loop is not redundant, which affects the reliability and wide-scale use of matrix switching.

Due to mis-cutting caused by loose components and wiring, there are no reliable guarantee measures for cross-cutting. The use of conventional detection methods will inevitably cause a large increase in costs. Possible causes of switching failures include: PLC switching output point failure, contactor relay contact adhesion, loose wiring, invalid strobe, strobe series connection, etc. These faults may cause equipment protection signal failure, equipment serial movement and other abnormal safety hazards. , it is extremely necessary to take technical measures to avoid the occurrence of these failures. Therefore, a low-cost detection device is needed to complete the high-coverage fault diagnosis function. When a switching fault occurs, various possible faults can be detected in time to improve the safety of the switching circuit.

Contents of the invention

The present invention aims to overcome the shortcomings of the prior art. In view of the above problems, the present invention provides a stage machinery switching control safety detection device and a method of use, which are suitable for small and medium-sized performance theaters. It solves the effective detection of switching circuits. Fault detection covers all foreseeable faults of matrix switching circuits. The switching circuit and inspection circuit are used as two components to complete the switching process together. Failure of any one of the two components can be determined. ; According to the judgment result, it is determined that operation is allowed, ensuring the safety requirements of the switching circuit. When a switching error is detected, the switching control selection is automatically adjusted as needed. If the fault cannot be eliminated, the equipment is prohibited from running, which improves the reliability of the system. It solves the problem of matrix switching safety detection and automatic redundancy switching to improve reliability. It has simple control and low cost, and realizes safety detection and multiple redundancy automatic switching.

In order to solve the above technical problems, the present invention provides the following technical solutions:

On the one hand, the present invention provides a stage machinery switching control safety detection device, which includes a matrix switching circuit, a patrol inspection and judgment circuit and a PLC controller participating in judgment and redundant switching. The matrix switching circuit and the patrol inspection and judgment circuit are electrically connected; The inspection and judgment circuit includes a multi-channel inverter electrically connected by a PLC controller through the inverter communication network, a matrix switching strobe and an inspection circuit electrically connected by the PLC controller, and the PLC controller, the frequency converter and the matrix switching strobe form a loop. The matrix switching circuit switching fault and inspection judgment circuit fault diagnosis are completed through the PLC controller. The matrix switching circuit connects the equipment motor and motor-related signals to the corresponding frequency converter; the PLC controller controls the circuit through inspection scanning. The connected device signal power supply and the external forced superposition signal are used to detect the matrix switching circuit status, and the device signal power supply and the external forced superposition signal are electrically connected to the matrix switching strobe.

A second aspect of the present invention provides a method for using a stage machinery switching control safety detection device, which includes the inspection circuit signal of the inspection judgment circuit and the matrix switching of the matrix switching circuit to complete fault diagnosis, and the inspection circuit signal of the power supply of the inspected equipment Judgment (including the power on and off status of the equipment under inspection). When a fault is detected during inspection, the matrix switching method is replaced and the inspection and judgment circuit is re-inspected;

When the switching of each strobe device is completed, the signal status of all selected devices is inspected. The PLC controller determines whether there is crosstalk to other switching devices; when the signal voltage status remains unchanged, the matrix switching strobe or inspection circuit is faulty. ;

The replacement matrix switching method includes: performing patrol inspection and control on the power supply of the two patrolled equipment through the patrol circuit, and inspecting the signal voltage changes of the patrolled equipment;

Use the PLC controller to detect changes in the protection signal status of the gating equipment and complete the detection of abnormal matrix switching faults of the patrolled equipment;

For the no-voltage status signal of the patrolled equipment, the PLC controller sends a forced superposition power supply instruction to the patrol circuit, and performs signal voltage detection on the protection signal status of the motor of the gating equipment.

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

The switching safety detection circuit of the present invention is used in stage machinery switching control, and is suitable for stage machinery matrix switching circuits composed of relay + contactor switching circuits and electronic circuits + contactors. It is composed of inspection circuit hardware and a PLC controller to complete the matrix. Switching fault inspection and multiple redundant automatic switching control. Under the premise that the cost of switching control has increased very little at present, the fault diagnosis of predictable matrix switching circuits is fully covered, the fault diagnosis is completed before the equipment is running, and the switching control method is adjusted based on the fault diagnosis results, effectively improving the matrix switching control The safety and reliability of the system, the application of stage machinery switching control are expanded, and the performance is stable. It solves the problem of fully covering the fault diagnosis of the matrix switching circuit and automatically re-routing the matrix switching gating. During the switching process, switching faults are automatically discovered; after a switching fault is discovered, the system automatically re-adjusts the switching plan and prohibits equipment operation if the fault cannot be eliminated. When the inspection circuit detects a switching failure, the matrix gating switch is replaced and the gating path is changed to achieve redundant switching control. During the switching and selection process of each device, a fully covered fault diagnosis is completed, and the diagnosis time is <1000ms. Complete safety inspections by cutting off equipment signal power to detect changes in signal status, and automatically replace redundant switching-related hardware based on detected matrix switching faults.

Description of drawings

Figure 1 is a schematic diagram of the basic unit of the inspection circuit of the stage machinery switching control safety detection device of the present invention.

Figure 2 is a protection signal inspection flow chart of the stage machinery switching control safety detection device of the present invention.

Figure 3 is a schematic diagram of the forced superposition switching signal circuit of the stage machinery switching control safety detection device of the present invention.

Figure 4 is an inspection program block diagram of the stage machinery switching control safety detection device of the present invention.

Figure 5 is a matrix switching block diagram of the stage machinery switching control safety detection device of the present invention.

Figure 6 is a block diagram of the cancellation matrix switching of the stage machinery switching control safety detection device of the present invention.

Figure 7 is a diagram of the matrix switching circuit safety detection system of the stage machinery switching control safety detection device of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

The stage machinery matrix switching control of the present invention uses a decoding circuit driver and a PLC controller to complete the switching inspection function. By adjusting the power supply of the switching equipment and detecting the signal status of the switching equipment, the switching fault detection is completed, including the safety inspection circuit and PLC controller related control. The principle of matrix switching is to program the addresses of the switched equipment (such as frequency converters) as 1~n, and the addresses of the patrolled equipment (motor and detection signals) as 1~m. The patrolled equipment is connected to the corresponding strobe according to the address number from small to large. The devices whose addresses are switched from small to large. The redundancy process is when a switching failure occurs: the number of all switched devices is n, the inverter address numbers are 1~n, the inverter address number is -1, and readjustment is performed, and the address of the inverter at address No. 1 is adjusted to 0, and the re-adjustment is completed. Arrange, and re-select the patrolled equipment according to the newly arranged inverter address.

Embodiment 1: As shown in Figure 7, a stage machinery switching control safety detection device is used for matrix switching safety inspection circuits, including a matrix switching circuit, an inspection judgment circuit and a PLC controller participating in judgment and redundant switching. The matrix switching circuit and the patrol inspection and judgment circuit are electrically connected; the patrol inspection and judgment circuit includes a multi-channel frequency converter electrically connected by a PLC controller through a frequency converter communication network, and a matrix switching strobe and patrol inspection circuit that are electrically connected by the PLC controller and controlled by the PLC controller. The PLC controller, frequency converter and matrix switching strobe form a loop, and the matrix switching circuit switching fault and inspection judgment circuit fault diagnosis are completed through the PLC controller. The matrix switching circuit connects the equipment motor and the signal strobe associated with the motor to the corresponding On the frequency converter; the PLC controller controls the electrically connected equipment signal power supply and external forced superposition signal through inspection and scanning, detects the matrix switching circuit status, and electrically connects the equipment signal power supply and external forced superposition signal to the matrix switching strobe. Matrix switching is the action process of a matrix switching circuit. PLC full matrix point output strobe (or decoding circuit) mode. Determine the fault status based on status detection. When a matrix switching circuit failure is found, the inverter sequence is adjusted, and matrix switching and inspection judgment are re-carried out to achieve safety detection and multiple redundant automatic switching.

Optionally, the matrix switching circuit operates a full matrix to complete the main circuit and protection signal gating switching of the equipment motor, including switching circuits and contactors; including encoder signals, gating equipment protection signals (loosening rope signals, brake status Action signal), contactor operating equipment motor main circuit, brake control, limit maintenance, upper limit, lower limit, load signal strobe switching. The switching circuit completes the device motor signal switching, including electronic circuits or relays.

Optionally, the DI point of the frequency converter collects the gating device protection signal after switching and transmits it to the PLC controller through the frequency converter communication network, or the gating device protection signal after switching collects the detection signal through the DI point of the PLC controller; matrix The switching device realizes device motor gating switching through the output strobe through the DO output point of the PLC controller. The PLC controller DO output point is a 6-bit PLC-DO output point, which realizes a maximum of 63 device strobe switching. Hardware decoding reduces the number of PLC output points and program decoding time.

The switching signals of each equipment motor are: 1. Motor main circuit line, 2. Motor brake control signal, 3. Equipment upper limit, 4. Lower limit, 5. Limit limit, 6. Motor wire rope rope signal, 7. Motor Encoder signal, 8. Motor temperature signal. The DI point of PLC is the switching input, DO is the switching output, and DI refers to the digital (switching) input signal, which is the on/off of the electrical secondary circuit and some status feedback. Signal voltage 24VDC or 220VAC. DO refers to digital (switching) output signal. Control signal or status signal sent from the controller Signal voltage 24VDC or 220VAC.

Optionally, as shown in Figure 2, the inspection circuit includes: the equipment motor power supply is electrically connected to the strobe switching circuit through the inspection circuit, and the strobe switching circuit is electrically connected to the PLC controller; the frequency converter is connected to the inspected circuit through the strobe switching circuit. The equipment motor is electrically connected; the frequency converter and the encoder of the strobe switching circuit are electrically connected; as shown in Figure 1, it also includes multiple basic units of inspection equipment connected to overloaders and decoders. The basic units of inspection equipment are controlled by PLC The DO output point of the device detects the signal status (24V, 24VED), and performs fault inspection on all gated matrix switching equipment through the decoding circuit; the inspection circuit supplies two power sources to each equipment motor, and inspects the gated equipment. When, cut off the power supply signal of the equipment's motor to perform gating equipment inspection. The inspection circuit can implement inspection of up to 63 devices.

Optionally, the gate switching circuit includes a matrix gate switching connecting the frequency converter and the PLC controller, an electronic switching and a contactor switching connecting the equipment motor power supply and the forced voltage superposition switching signal.

Optionally, the basic unit of the inspection equipment controls the power supply of 16 stage mechanical equipment (dual power supply 24V, 24VED). The PLC controller selects the inspection equipment through circuit terminal XDC2 decoding. When no equipment is selected for inspection, the equipment power supply All are connected normally. After the device is selected, cut off the power supply of the device 24V and 24VED and force all switching signal states to be no voltage; judge the status changes of the signals of the patrolled equipment to determine whether the matrix switching is correct and whether the switching circuit components are faulty. 1 means there is voltage, 0 means there is no voltage.

As shown in Figure 2, a method of using a stage machinery switching control safety detection device includes the inspection circuit signal of the inspection judgment circuit and the matrix switching of the matrix switching circuit to complete fault diagnosis, and the inspection circuit signal of the power supply of the inspected equipment Judgment (including the power on and off status of the equipment under inspection). When a fault is detected during inspection, the matrix switching method is replaced and the inspection and judgment circuit is re-inspected;

When the switching of each strobe device is completed, the signal status of all selected devices is inspected. The PLC controller determines whether there is crosstalk to other switching devices; when the signal voltage status remains unchanged, the matrix switching strobe or inspection circuit is faulty. ;

The replacement matrix switching method includes: performing patrol inspection and control on the power supply of the two patrolled equipment through the patrol circuit, and inspecting the signal voltage changes of the patrolled equipment;

Use the PLC controller to detect changes in the protection signal status of the gating equipment and complete the detection of abnormal matrix switching faults of the patrolled equipment;

For the no-voltage status signal of the patrolled equipment, the PLC controller sends a forced superposition power supply instruction to the patrol circuit, and performs signal voltage detection on the protection signal status of the motor of the gating equipment. Figure 4 shows the re-matrix switching method when a fault is detected during inspection.

As shown in Figure 3, the signal inspection process, because the level is uncertain, when the inspection reaches the switching device, the encoder signal status passes through the forced voltage, and the inspection switching interface is judged. The contactor main circuit and the contactor auxiliary contact pass For mechanical linkage connection, the main contact state is consistent with the contactor auxiliary signal contact state. If the main contact is stuck, it can be determined and confirmed by detecting the signal state before switching. The forced "1" signal superposition switching circuit forms an "OR" logical relationship with the detection signal. At the same time, the mutual influence between different equipment signals is effectively isolated through the optocoupler. The equipment motor is marked as M.

Optionally, the inspection circuit signal judgment of the power supply of the inspected equipment includes: when there is no output during the inspection, the equipment signal power supply is turned on, and whether the protection signal of each strobe equipment is in full voltage state; for other encoder signals, PLC control When the detector detects that the equipment signal status is not satisfactory and is not all voltage, it will give a forced output superimposed voltage signal, and then detect again to determine whether the protection signal of each strobe device is in full voltage status. When the signal status is in full voltage, it will enter the inspection equipment output detection In the next step, a switching failure occurs in the contactor contact, and the inspection device address is output with a delay; if the voltage is not full, a device switching error message is given; the matrix switching signal state is detected to see whether there is no voltage at all. When the device signal state is detected When there is voltage, the switching point is faulty;

After inspecting the address strobe output of the strobe device, it enters the inspection of power disconnection. The PLC detects the matrix switching signal status to determine whether the feedback signal of each device satisfies the signal status of no voltage. When the detection signal has no voltage at all, the matrix switching is normal; If no voltage is satisfied, an equipment switching error message will be given; the PLC controller replaces the matrix switching method, re-controls the matrix gating switching of the gated equipment, completes the redundant matrix switching, and re-inspects the judgment; if the redundant switching is exceeded When the allowed times are reached, the matrix switching gating fails and the device with gating switching failure is not allowed to operate. The inverter of the switching device with successful switching is powered on and the switching device runs.

In the event of a switching failure, the newly switched circuit gate is selected through redundant switching. The number of redundant matrix switching times is the number of matrix switching inverters. Each time there is an abnormal matrix switching failure, the inverter sequence is automatically adjusted, matrix switching is performed again, and failsafe is performed again. Inspect and avoid faulty circuits. Abnormal faults of switching circuit components and inspection circuit components include: switching circuit component faults, inspection circuit component faults, and protection signal abnormal faults.

The circuit delay of each inspection device is within 50~100ms; to complete the inspection of one device, in order not to affect the gating of the next device, the inspection of 10 devices should not exceed 1000ms.

The specific process of protection signal inspection is as follows: As shown in Figure 4, the switching line is judged to set the initial value, the boom number switched by the frequency converter is judged, the number of matrix switching methods is not changed, and the external signal status of the equipment switched to the frequency converter is detected. 1 Force the output to superimpose 1 signal to the switching line input end and wait. It detects that the external signal status of the equipment switched to the inverter is all 1. Cut off the signal power supply and wait. It detects that the external signal status of the equipment switched to the inverter is all 0; detect the next Frequency converter switching, frequency converter switching inspection and detection is completed; set the switching completion flag, replace the number of matrix switching methods, RET.

If it is detected that the external signal status of the device switched to the inverter is not all 1 or 0, change the matrix switching method, clear the strobe output of the inverter device, change the strobe output of the inverter device according to the cycle again, and return to the initial switching line judgment setting. value;

Replace the number of matrix switching methods. After switching the failure flag, RET;

The frequency converter switching inspection and inspection has not been completed. Determine the boom equipment number of the frequency converter switching and detect the next frequency converter switching.

Matrix switching process: As shown in Figure 5, the boom equipment number is strobe switched, the boom switching enable signal is used, the boom equipment has a strobe switching completed flag, the forward and reverse switching flag DIR is judged to be 0, and the inverter number is 1. If the frequency converter has no disabled flag, it is judged that the frequency converter is not idle, and the forward and reverse switching flags are judged. If the DIR of the forward and reverse switching flag is judged to be 0, the frequency converter increases by 1, and the frequency converter scan is completed; if the frequency converter is idle, the matrix is corner-cut, and the full matrix time jumps. After this step, set the boom equipment number to the inverter address (occupancy flag), add 1 to the switching boom equipment number, and after the switching boom detection is completed, it is greater than the total number of devices, RET.

The boom switching is not detected yet, and the boom switching enable signal is used;

The forward and reverse switching flag DIR is not 0, the total number of frequency converters is i,

The frequency converter has a disabled flag, the frequency converter strobe boom is cleared, the forward and reverse switching flag DIR is not 0, the frequency converter decreases 1, and the frequency converter scans, the switching boom device increases by 1. The switching status is always saved after matrix switching. Figure 6 shows that after canceling matrix switching, all gated devices are cancelled.

To complete the switching of each device, an inspection of all selected devices is required to prevent crosstalk between all possible devices. In order not to affect the gating of the next device, the inspection of each patrolled device is completed within the circuit delay of 50~100ms, and the inspection of 10 devices shall not exceed 1000ms.

The above description is only for illustrating the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention can be made. All should be included in the protection scope of the present invention.

Claims (10)

1. The utility model provides a stage machinery switches control safety inspection device, includes matrix switching circuit, inspection judgement circuit and participates in judging and redundant PLC controller who switches, its characterized in that: the matrix switching circuit is electrically connected with the inspection judging circuit; the inspection judging circuit comprises a plurality of frequency converters electrically connected with the PLC through a frequency converter communication network, and a matrix switching gating and inspection circuit electrically connected with the PLC under control of the PLC, wherein the PLC, the frequency converters and the matrix switching gating form a loop, the switching failure of the matrix switching circuit and the fault diagnosis of the inspection judging circuit are completed through the PLC, and the matrix switching circuit connects the equipment motor and the signal gating associated with the motor to the corresponding frequency converter; the PLC controls the electrically connected equipment signal power supply and external forced superposition signals through inspection scanning, detects the state of the matrix switching circuit, and the electrically connected equipment signal power supply and external forced superposition signals are electrically connected with matrix switching gating.

2. The stage mechanical switching control safety detection device according to claim 1, wherein the matrix switching circuit operates a main circuit of a full matrix equipment motor and signal gating switching, and comprises a switching circuit and a contactor; the switching circuit includes: encoder signals, gating equipment protection signals, contactor operation equipment motor main loop, brake control, limit maintenance, upper limit, lower limit and load signal gating switch, wherein the switch circuit comprises an electronic circuit or a relay.

3. The stage mechanical switching control safety detection device according to claim 2, wherein the equipment protection signal after switching is collected by a DI point of the frequency converter, and is transmitted to the PLC controller through a communication network of the frequency converter, or the equipment protection signal after switching is collected by a DI point of the PLC controller; the matrix switching device realizes the gating switching of the motor of the device through the output gating by the DO output point of the PLC.

4. The stage mechanical switching control safety detection device according to claim 1, wherein the inspection judgment circuit includes: the equipment motor power supply is electrically connected with the gating switching circuit through the inspection circuit, and the gating switching circuit is electrically connected with the PLC; the frequency converter is electrically connected with the equipment motor to be patrolled through the gating switching circuit; the frequency converter is electrically connected with the encoder of the gating switching circuit; the system also comprises an overload device and a plurality of inspection equipment basic units connected with a decoder, wherein the inspection equipment basic units output a point detection signal state through a PLC (programmable logic controller) DO, and fault inspection is carried out on all the gated matrix switching equipment through a decoding circuit; and the inspection circuit supplies two paths of power to each equipment motor, and cuts off the power signal of the equipment motor to carry out inspection of gating equipment when the gating equipment is inspected.

5. The stage mechanical switching control safety inspection device according to claim 4, wherein the gating switching circuit includes a matrix gating switching connecting the frequency converter and the PLC controller, an electronic switching connecting the equipment motor power supply and the forced voltage superposition switching signal, and a contactor switching.

6. The safety detection device for switching control of stage machinery according to claim 4, wherein the inspection equipment basic unit controls a plurality of stage machinery power supplies, the PLC controller selects inspection equipment through the circuit connection terminal XDC2 decoding, when the unselected equipment is inspected, all equipment power supplies are normally turned on, and after the equipment is selected, all switching signal states of the equipment power supplies are cut off to force no voltage; and judging the state change of the signal of the equipment to be patrolled, and determining whether the matrix switching is correct or not and whether the matrix switching circuit element fails or not.

7. The use method of the stage mechanical switching control safety detection device comprises the steps of finishing fault diagnosis by switching the inspection circuit signals of the inspection judgment circuit and the matrix of the matrix switching circuit, and is characterized in that the inspection circuit signals of the power supply of the inspected equipment are judged, when the inspection is finished, the matrix switching method is replaced, and the inspection judgment circuit is re-inspected;

when the switching of each gating device is finished, carrying out inspection on the signal states of all selected devices, and judging whether crosstalk exists on other switching devices by a PLC (programmable logic controller); when the signal voltage state is unchanged, the matrix switching gating or inspection circuit fails;

the replacement matrix switching method comprises the following steps: the inspection circuit is used for performing inspection control on two paths of inspected equipment power supplies, and inspecting the signal voltage change of the inspected equipment;

detecting the state change of the protection signal of the gating equipment by using a PLC controller to finish detecting the abnormal switching faults of the matrix of the equipment to be patrolled;

and (3) sending a forced superposition power supply instruction to the inspection circuit through the PLC for the no-voltage state signal of the inspected equipment, and detecting the signal voltage of the protection signal state of the motor of the gating equipment.

8. The method for using a stage mechanical switching control safety inspection device according to claim 7, wherein the step of determining the inspection circuit signal of the power source of the inspected equipment comprises: when the inspection is not output, the power supply of the equipment signal is switched on, and each gating equipment protects whether the signal is in a full-voltage state or not; for other encoder signals, when the PLC detects that the signal state of the equipment is not satisfied and is not the voltage, the PLC gives out a compulsory output superposition voltage signal, detects and judges whether the protection signal of each gating equipment is in a full voltage state again, and when the signal state is detected to be in a full voltage state, the PLC enters the inspection equipment to output the next detection step, then the contact of the contactor is subjected to switching failure, and the address of the inspection equipment is output and then delayed; giving a device switching error prompt if the voltage is not the full voltage; detecting whether the state of the matrix switching signal is completely voltage-free, and if the state of the equipment signal is detected to be voltage-free, then the switching point is in fault; after the address of the inspection gating device is output in a gating way, the inspection gating device enters into the inspection of power off, the PLC detects the state of a matrix switching signal to judge whether the feedback signal of each device meets the state of no voltage, and when the detection signal has no voltage, the matrix switching is normal; if the total no-voltage is not satisfied, giving a device switching error prompt; the PLC controller replaces a matrix switching method, performs matrix gating switching control on the gated equipment again, completes redundant matrix switching, and re-inspection judgment; when the redundancy switching permission times are exceeded, the matrix switching gating fails, equipment with gating switching failure is not allowed to operate, a switching equipment frequency converter which is successfully switched is electrified, and the switching equipment operates.

9. The method according to claim 7, wherein a switching failure occurs, a newly switched loop gate is selected by redundancy switching, the number of redundancy matrix switching is the number of matrix switching frequency converters, each time the matrix switching fails abnormally, the frequency converters are automatically adjusted to order, the matrix switching is resumed, and the fail-safe inspection is performed again.

10. The method of claim 7, wherein the circuit delay of the equipment is within 50-100 ms.