A blower inverter fault protection circuit, method and distributed control system

Abstract

The present invention relates to the technical field of coke oven gas treatment, and in particular to a blower inverter fault protection circuit and a distributed control system thereof, wherein the protection circuit comprises a first drive circuit, a second drive circuit, a first protection circuit and a second protection circuit, wherein the first drive circuit comprises a power supply, a first inverter, a first switch module and a first blower connected in series in sequence; the second drive circuit comprises the power supply, the second inverter, the second switch module and the second blower connected in series in sequence; the first protection circuit comprises a third switch module and a protection power supply connected in series with the first blower in sequence; the second protection circuit comprises a fourth switch module and the protection power supply connected in series with the second blower in sequence; when the inverter fails, the first or second protection branch is turned on to continue to provide the blower with corresponding power supply and standard operating frequency, so as to prevent safety accidents caused by the inverter failure.

Description

Technical Field

[0001] The invention relates to the technical field of coke oven gas treatment, and in particular to a blower inverter fault protection circuit, method and distributed control system thereof. Background Art

[0002] Coke oven gas is a combustible gas obtained during the coking process when coke and tar products are produced. It is an important by-product of the coking process. One of the important equipment for coke oven gas treatment is the blower. The blast cooling system consists of two blast cooling fans and independent frequency conversion systems. Under normal production conditions, the amount of raw gas produced by the coke oven is 60,000 NM 3 / h, and the raw gas produced is sucked out by the blower.

[0003] Every year, the inverter stops due to inverter failure or temporary voltage drop in the power supply system, causing low voltage, about 5 times. When the blower stops running due to power outage or inverter failure, the pressure of the gas collecting pipe at the top of the coke oven increases instantly, causing coke oven gas leakage.

[0004] The patent with the publication number CN2735411Y provides a frequency converter bypass device for a boiler fan, which specifically discloses that the bypass device includes a frequency converter, an inlet switch, a bypass switch, a high-voltage motor, a fan damper and a damper actuator; an outlet switch is provided between the frequency converter and the fan motor, the inlet end of the outlet switch is connected to the frequency converter, and the outlet end is connected to the high-voltage motor; the frequency converter fault signal is output to the input terminal of the program control device, and the control signal terminal of the program control device is respectively connected to the signal terminals of the inlet switch, the outlet switch, the bypass switch and the fan damper actuator; the fan damper actuator drives the fan damper through a mechanical connection. Its advantage is that when the frequency converter fails, the fan damper can be quickly actuated to reduce the fluctuation of the suction / supply air volume, thereby reducing the impact on the boiler combustion and preventing the boiler from extinguishing.

[0005] In practice, the inventors found that the above-mentioned prior art has the following defects:

[0006] The technical problem that the above patent can solve is that when the frequency converter fails, it can quickly control the movement of the baffle to reduce the fluctuation of the suction volume, thereby reducing the impact on boiler combustion. However, the reduction in the suction volume will cause the pressure of the gas collecting pipe at the top of the coke oven to increase instantly, causing coke oven gas leakage. Summary of the invention

[0007] In order to solve the above technical problems, the purpose of the present invention is to provide a blower inverter fault protection circuit, method and distributed control system. The technical solution adopted by the protection circuit is as follows:

[0008] A blower inverter fault protection circuit, the protection circuit comprising:

[0009] The first drive circuit comprises a power supply, a first frequency converter, a first switch module and a first blower connected in series in sequence, and is used to drive the first blower to operate through the first frequency converter;

[0010] A second driving circuit comprises the power supply, a second frequency converter, a second switch module and a second blower connected in series in sequence, and is used to drive the second blower to operate through the second frequency converter;

[0011] a first protection circuit, comprising a third switch module and a protection power supply connected in series with the first blower in sequence, for conducting the first protection circuit through the third switch module and driving the corresponding blower to operate normally through the protection power supply when the first inverter fails; and

[0012] A second protection circuit includes a fourth switch module and the protection power supply which are sequentially connected in series with the second blower, and is used to conduct the second protection circuit through the fourth switch module and drive the corresponding blower to operate normally through the protection power supply when the second frequency converter fails;

[0013] Among them, the first switch module and the second switch module constitute a first interlocking switch, which is used to turn on the first drive branch or the second drive branch; the third switch module and the fourth switch module constitute a second interlocking switch, which is used to turn on the corresponding first protection branch or the second protection branch when the first drive branch or the second drive branch fails.

[0014] Further, the second interlock switch includes a third interlock branch and a fourth interlock branch;

[0015] The third interlocking branch is composed of a normally closed contact of a fifth AC contactor, a coil of a sixth AC contactor and a controller in series, and the normally open contact of the fifth AC contactor is connected to the first protection circuit;

[0016] The fourth interlocking branch is composed of the normally closed contact of the sixth AC contactor, the coil of the fifth AC contactor and the controller connected in series, and the normally open contact of the sixth AC contactor is connected to the second protection circuit.

[0017] Further, the first switch module in the first interlock switch includes a first drive branch and a first protection detection branch, and the second switch module includes a second drive branch and a second protection detection branch;

[0018] The first driving branch is composed of a coil of a first AC contactor, a normally closed contact of a second AC contactor and a controller in series;

[0019] The first protection detection branch is composed of a coil of the second AC contactor, a normally closed contact of the first AC contactor, a normally closed contact of the fourth AC contactor and a controller connected in series;

[0020] The second drive branch is composed of a coil of a third AC contactor, a normally closed contact of a fourth AC contactor and a controller in series;

[0021] The second protection detection branch is composed of a coil of a fourth AC contactor, a normally closed contact of a third AC contactor, a normally closed contact of a second AC contactor and a controller connected in series;

[0022] Among them, the normally open contact of the first AC contactor is connected to the first drive circuit; the normally open contact of the third AC contactor is connected to the second drive circuit.

[0023] Further, the second interlock switch further includes a third protection indication branch and a fourth protection indication branch;

[0024] The third protection indication branch is composed of a coil of the first relay, a normally closed contact of the second relay of the second relay and a controller connected in series; the normally open contact of the first relay is connected to the third interlocking branch, the normally closed contact is connected to the fourth interlocking branch, and the third interlock indication branch is connected in parallel with the third interlocking branch;

[0025] The fourth protection indication branch is composed of the coil of the second relay, the normally closed contact of the first relay and the controller connected in series; the normally open contact of the second relay is connected to the fourth interlocking branch, the normally closed contact is connected to the third interlocking branch, and the fourth interlock indication branch is connected in parallel with the fourth interlocking branch;

[0026] Wherein, when the third interlock indication branch or the fourth interlock indication branch is turned on, the controller controls the corresponding indicator light to light up.

[0027] Further, the first switch module includes a first drive indication branch composed of a third relay and a fourth relay; the second switch module includes a second drive indication branch composed of a fifth relay and a sixth relay;

[0028] The first drive indication branch is composed of a coil of a third relay connected in parallel with a coil of a first AC contactor, a normally closed contact of the third relay connected to the first protection detection branch, a coil of a fourth relay connected in parallel with a coil of a second AC contactor, and a normally closed contact of the fourth relay connected to the first drive branch;

[0029] The second drive indication branch is composed of a coil of a fifth relay connected in parallel with a coil of a third AC contactor, a normally closed contact of the fifth relay connected to the second protection detection branch, a coil of a sixth relay connected in parallel with a coil of a fourth AC contactor, and a normally closed contact of the sixth relay connected to the second drive branch;

[0030] Wherein, when the first drive indication branch or the second drive indication branch is turned on, the controller controls the corresponding indicator light to light up.

[0031] Another object of the present invention is to provide a distributed control method, the technical solution adopted by the method is as follows:

[0032] A distributed control method, the method comprising the following steps:

[0033] The switch module controls the first frequency converter to drive the first blower to operate, or the switch module controls the second frequency converter to drive the second blower to operate;

[0034] When the first frequency converter fails, the first protection circuit is turned on through the third switch module to protect the power supply to drive the first blower to operate normally, and the second protection circuit is turned off under the action of the second interlock switch;

[0035] When the second frequency converter fails, the second protection circuit is turned on through the fourth switch module, and the protection power supply drives the second blower to operate normally. Under the action of the second interlock switch, the first protection circuit is disconnected.

[0036] Furthermore, the method further comprises the following steps:

[0037] The switch module drives the connection between the first inverter and the first blower through the first interlock switch, and disconnects the connection between the protection power supply and the first blower; or

[0038] The protection power supply is turned on to drive the first blower to operate, and the connection between the first inverter and the first blower is disconnected.

[0039] Furthermore, the method further comprises the following steps:

[0040] The switch module drives the connection between the second frequency converter and the second blower through the first interlock switch, and disconnects the connection between the protection power supply and the second blower; or

[0041] The conduction protection power source drives the second blower to operate, and disconnects the connection between the second frequency converter and the second blower.

[0042] Another object of the present invention is to provide a distributed control system, the technical solution adopted by the system is as follows:

[0043] A distributed control system adopts the blower inverter fault protection circuit.

[0044] The present invention has the following beneficial effects:

[0045] In the embodiment of the present invention, two independent blowers are arranged and controlled by two independent drive branches. A first interlocking switch is used to achieve the purpose of preventing gas from being released, with one blower in backup and the other in use. Protection circuits are respectively arranged on the drive branches of the blowers. When a frequency converter in a corresponding drive branch fails, a corresponding protection circuit is turned on through a switch module to continue to provide the blower with a corresponding power supply and a standard operating frequency, thereby preventing safety accidents caused by a frequency converter failure. The two protection circuits are ensured by a second interlocking switch to ensure that after switching to the protection circuit, the first protection circuit or the second protection circuit is turned on to ensure that there is no gas release.

[0046] Before using this protection circuit, the cooling fan tripped about 5 times a year due to frequency conversion, and the gas release was about 30,000 NM each time 3 After using this protection circuit, the annual reduction of gas emission is about 150000NM 3 / year, making great contribution to social environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A structural block diagram of a blower inverter fault protection circuit provided by an embodiment of the present invention;

[0048] Figure 2 is a structural schematic diagram of a third interlocking branch and a fourth interlocking branch in a second interlocking switch;

[0049] Figure 3 is a structural schematic diagram of a driving branch and a protection detection branch in a first interlocking switch;

[0050] Figure 4 is a structural schematic diagram of a protection indication branch in a second interlock switch;

[0051] Figure 5 is a structural schematic diagram of a drive indication branch in a first interlock switch;

[0052] Figure 6 A structural schematic diagram of a blower inverter fault protection circuit provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0053] The present invention is described in detail below through specific embodiments in combination with the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict, and the protection scope of the present invention is not limited thereto.

[0054] It should be noted that the terms "first" and "second" involved in the embodiments of the present invention are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Terms such as "connected" and "connect" should be understood in a broad sense. For example, it can be an electrical connection, a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] The controller used in this embodiment uses a microprocessor of a PLC or a DCS system as a controller for control.

[0056] In normal operation, in order to achieve continuous production, reliable stability, and safe production, and to prevent the blower itself from malfunctioning, two independent blowers are set up for variable frequency operation, one of which is used as a backup blower to prevent safety accidents. However, in order to eliminate the occurrence of safety accidents caused by inverter failure, the safety protection circuit needs to be further improved.

[0057] See also Figure 1 , which shows a structural block diagram of a blower inverter fault protection circuit provided by an embodiment of the present invention, the protection circuit includes a first drive branch, a second drive branch, a first protection circuit and a second protection circuit.

[0058] The first drive circuit is composed of a power supply 100, a first frequency converter 200, a first switch module 30 and a first blower 400 connected in series in sequence. In normal operation, the first drive branch, when the first switch module 30 is turned on, drives the first blower 400 to operate normally through the first frequency converter 200.

[0059] The second drive circuit is composed of the power supply 100, the second frequency converter 500, the second switch module 31 and the second blower 600 connected in series in sequence. Similar to the first drive circuit, in normal operation, the second drive circuit drives the second blower 600 to operate through the second frequency converter 500 when the second switch module 31 is turned on.

[0060] The first protection circuit includes a third switch module 80 and a protection power supply 700 which are sequentially connected in series with the first blower 400. When the first frequency converter in the first drive circuit fails, the first protection circuit provides power to the first blower, and the frequency provided by the power supply is a normal working frequency, so as to prevent the first blower from failing to work due to the failure of the first frequency converter, thereby preventing a safety accident from occurring. When the first frequency converter 200 fails, the first protection circuit is turned on by turning on the switch module 80, and the corresponding blower is driven to operate normally by the protection power supply 700.

[0061] The second protection circuit includes a fourth switch module 81 and the protection power supply 700 which are sequentially connected in series with the second blower 600. The second protection circuit has the same circuit structure as the first protection circuit and shares the same protection power supply, and the frequency provided by the protection power supply is a normal working frequency. When the second frequency converter 500 fails, the second protection circuit is turned on by turning on the switch module 81, and the corresponding blower is driven to operate normally by the protection power supply 700.

[0062] In order to prevent gas from escaping and to make the blower a backup, the first blower and the second blower do not work at the same time, so the first protection circuit and the second protection circuit do not work at the same time. The first switch module 30 and the second switch module 31 constitute a first interlocking switch 300. When the first switch module 30 is turned on, the second switch module 31 is turned off, ensuring that when the first drive circuit is turned on, the second drive circuit is in a disconnected state; when the second switch module 31 is turned on, the first switch module 30 is turned off, ensuring that when the second drive circuit is turned on, the first drive circuit is in a disconnected state. Similarly, the third switch module 80 and the fourth switch module 81 constitute a second interlocking switch 800, which is used to turn on the corresponding first protection branch or second protection branch when the first drive circuit or the second drive circuit fails. When the first drive circuit fails, when the third switch module 80 is turned on, the fourth switch module 81 is turned off, ensuring that when the first protection branch is turned on, the second protection branch is in a disconnected state. When the second drive circuit fails, the fourth switch module 81 is turned on and the third switch module 80 is turned off, ensuring that when the second protection branch is turned on, the first protection branch is in a disconnected state.

[0063] To sum up, the embodiment of the present invention sets up two independent blowers, which are controlled by two independent drive branches, and achieves the purpose of one backup and one use through the first interlocking switch. Protection circuits are respectively set on the drive branches of the blowers. When the frequency converter in the corresponding drive branch fails, the corresponding protection circuit is turned on by the switch module, and the corresponding power supply and standard operating frequency are continued to be provided to the blower, which can prevent safety accidents caused by the frequency converter failure. The two protection circuits are ensured by the second interlocking switch. After switching to the protection circuit, the first protection circuit or the second protection circuit is turned on, so as to achieve the purpose of one backup and one use of the blower and ensure that there is no gas release.

[0064] See also Figure 2, which shows a schematic diagram of the structure of the third interlocking branch and the fourth interlocking branch in the second interlocking switch provided by an embodiment of the present invention, wherein the second interlocking switch includes a third interlocking branch 201 and a fourth interlocking branch 202, the third interlocking branch 201 is composed of the normally closed contact of the fifth AC contactor 4KM1, the coil of the sixth AC contactor 4KM2 and the controller in series, and the normally open contact of the fifth AC contactor 4KM1 is connected to the first protection circuit; the fourth interlocking branch 202 is composed of the normally closed contact of the sixth AC contactor 4KM2, the coil of the fifth AC contactor 4KM1 and the controller in series, and the normally open contact of the sixth AC contactor is connected to the second protection circuit. When the third interlocking branch 201 is turned on, the coil of the sixth AC contactor 4KM2 is turned on, the normally closed contact of the sixth AC contactor 4KM2 is disconnected, and the fourth interlocking branch 202 is disconnected, so as to achieve the purpose of interlocking. Similarly, when the fourth interlocking branch 202 is turned on, the coil of the fifth AC contactor 4KM1 is turned on, the normally closed contact of the fifth AC contactor 4KM1 is disconnected, and the third interlocking branch 201 is disconnected, so as to achieve the purpose of interlocking. Therefore, the third interlocking branch and the fourth interlocking branch can achieve the purpose of interlocking.

[0065] It should be noted that the L11 and N11 terminals in the figure are connected to the corresponding ports of the controller. The connection method of the terminals in the following figures is the same as the connection method of the terminals here, and they are all connected to the corresponding ports of the controller, which will not be repeated below.

[0066] See also Figure 3 , which shows a schematic diagram of the structure of the driving branch and the protection detection branch in the first interlock switch provided by an embodiment of the present invention, wherein the first interlock switch includes a first switch module and a second switch module. The first switch module includes a first driving branch 301 and a first protection detection branch 302, and the second switch module includes a second driving branch 303 and a second protection detection branch 304.

[0067] The first drive branch 301 is composed of the coil of the first AC contactor 1KM1, the normally closed contact of the second AC contactor 1KM2 and the controller in series. The first protection detection branch 302 is composed of the coil of the second AC contactor 1KM2, the normally closed contact of the first AC contactor 1KM1, the normally closed contact of the fourth AC contactor 2KM2 and the controller in series. The second drive branch 303 is composed of the coil of the third AC contactor 2KM1, the normally closed contact of the fourth AC contactor 2KM2 and the controller in series. The second protection detection branch 304 is composed of the coil of the fourth AC contactor 2KM2, the normally closed contact of the third AC contactor 2KM1, the normally closed contact of the second AC contactor 1KM2 and the controller in series. Among them, the normally open contact of the first AC contactor 1KM1 of the first switch module is connected to the first drive circuit; the normally open contact of the third AC contactor 2KM1 of the second switch module is connected to the second drive circuit.

[0068] When the first drive branch 301 is turned on, the coil of the first AC contactor 1KM1 is turned on, and the normally closed contact of the first AC contactor 1KM1 is disconnected, so the first protection detection branch 302 is disconnected, the normally open contact of the first AC contactor 1KM1 is turned on, the first drive circuit is turned on, and the first blower operates normally. When the frequency converter fails, the first protection detection branch 302 is turned on, the coil of the second AC contactor 1KM2 is turned on, and the normally closed contact of the second AC contactor 1KM2 is disconnected, so the first drive branch 301 is disconnected, the second protection detection branch 304 is disconnected, and the first protection detection branch 302 supplies power to the first blower to ensure the normal operation of the first blower.

[0069] When the second drive branch 303 is turned on, the coil of the third AC contactor 2KM1 is turned on, and the normally closed contact of the third AC contactor 2KM1 is disconnected, so the second protection detection branch 304 is disconnected, the normally open contact of the third AC contactor 2KM1 is turned on, the second drive circuit is turned on, and the second blower operates normally. When the frequency converter fails, the second protection detection branch 304 is turned on, the coil of the fourth AC contactor 2KM2 is turned on, and the normally closed contact of the fourth AC contactor 2KM2 is disconnected, so the second drive branch 303 and the first protection detection branch 302 are disconnected, and the second protection detection branch 304 supplies power to the second blower to ensure the normal operation of the second blower.

[0070] See also Figure 4 , which shows a structural schematic diagram of a protection indication branch in a second interlocking switch provided by an embodiment of the present invention. The second interlocking switch also includes a third protection indication branch 401 and a fourth protection indication branch 402.

[0071] The third protection indication branch 401 is composed of the coil of the first relay 4KA1, the normally closed contact of the second relay of the second relay 4KA2 and the controller connected in series, the normally open contact of the first relay 4KA1 is connected to the third interlocking branch 202, the two normally closed contacts of the first relay 4KA1 are respectively connected to the fourth protection indication branch 402 and the fourth interlocking branch 201, and the third protection indication branch 401 is connected in parallel with the third interlocking branch 202. When the first inverter fails, the coil of the first relay 4KA1 is first turned on, at which time the normally open contact of the first relay 4KA1 is turned on, and the corresponding normally closed contact is disconnected, ensuring that when the third interlocking branch 202 is turned on, the fourth interlocking branch 201 and the fourth protection indication branch 402 are disconnected, and the controller controls the corresponding indicator light.

[0072] The fourth protection indication branch 402 is composed of the coil of the second relay 4KA2, the normally closed contact of the first relay 4KA1 and the controller connected in series, the normally open contact of the second relay 4KA2 is connected to the fourth interlocking branch 201, the two normally closed contacts of the second relay are respectively connected to the third protection indication branch 401 and the third interlocking branch 201, and the fourth protection indication branch 402 is connected in parallel with the fourth interlocking branch 201. When the second inverter fails, the coil of the relay 4KA2 is turned on first, at which time the normally open contact of the second relay 4KA2 is turned on, and the corresponding normally closed contact is disconnected, ensuring that when the fourth interlocking branch 201 is turned on, the third protection indication branch 401 and the third interlocking branch 201 are disconnected, and the controller controls the corresponding indicator light.

[0073] See also Figure 5 , which shows a structural schematic diagram of the drive indication branch in the first interlock switch provided by an embodiment of the present invention, wherein the first switch module includes a first drive indication branch composed of a third relay 1KA1 and a fourth relay 1KA2; the second switch module includes a second drive indication branch composed of a fifth relay 2KA1 and a sixth relay 2KA2. The coil of the third relay 1KA1 is connected in parallel with the coil of the first AC contactor 1KM1, and the normally closed contact of the third relay 1KA1 is connected to the first protection detection branch 302. The coil of the fourth relay 1KA2 is connected in parallel with the coil of the second AC contactor 1KM2, and the normally closed contact of the fourth relay 1KA2 is connected to the first drive branch 301. When the first protection detection branch 302 or the first drive branch 301 is turned on, ensure that the other branch is disconnected, and the controller controls the corresponding indicator light.

[0074] The coil of the fifth relay 2KA1 is connected in parallel with the coil of the third AC contactor 2KM1, and the normally closed contact of the fifth relay 2KA1 is connected to the second protection detection branch 304. The coil of the sixth relay 2KA2 is connected in parallel with the coil of the fourth AC contactor 2KM2, and the normally closed contact of the sixth relay 2KA2 is connected to the second drive branch 303. When the second protection detection branch 304 or the second drive branch 303 is turned on, ensure that the other branch is disconnected, and the controller controls the corresponding indicator light.

[0075] See also Figure 6 , which shows a structural schematic diagram of a blower inverter fault protection circuit provided by another embodiment of the present invention, the protection circuit includes a first drive circuit, a second drive circuit, a first protection circuit and a second protection circuit, the first drive circuit and the second drive power supply share a power supply VCC, the power supply VCC is connected to the motor M1 of the first blower through the first inverter UF1 and the normally open contact of the first AC contactor 1KM1 to form a first drive circuit, and the power supply VCC is connected to the motor M2 of the second blower through the normally open contact of the second inverter UF2 and the third AC contactor 2KM1 to form a second drive circuit. The first protection circuit and the second protection circuit share a backup power supply VCC1, and the backup power supply VCC1 is connected to the motor M1 of the first blower through the normally open contact of the fifth AC contactor 4KM1 to form a first protection circuit. The backup power supply VCC1 is connected to the motor M2 of the second blower through the normally open contact of the sixth AC contactor 4KM2 to form a second protection circuit.

[0076] Preferably, the power supply VCC is connected to the first frequency converter UF1 and the second frequency converter UF2 through circuit breakers QF01 and QF02, respectively. The backup power supply VCC1 is connected to the normally open contacts of the fifth AC contactor 4KM1 and the sixth AC contactor 4KM2 through circuit breaker QF03.

[0077] When the first frequency converter UF1 fails, the controller controls the first protection circuit to be turned on, and the first protection circuit outputs the corresponding working frequency to provide working power for the blower to ensure the normal operation of the blower. Similarly, when the second frequency converter UF2 fails, the controller controls the second protection circuit to be turned on, and the second protection circuit outputs the corresponding working frequency to provide working power for the blower to ensure the normal operation of the blower and prevent safety accidents caused by blower failures.

[0078] Another object of the present invention is to provide a distributed control method, the technical solution adopted by the method is as follows:

[0079] A distributed control method, the method comprising the following steps:

[0080] The first frequency converter is controlled by the switch module to drive the first blower to operate, or the switch module controls the second frequency converter to drive the second blower to operate; when the first frequency converter fails, the first protection circuit is turned on by the third switch module, and the protection power supply drives the first blower to operate normally, and the second protection circuit is disconnected under the action of the second interlock switch; when the second frequency converter fails, the second protection circuit is turned on by the fourth switch module, and the protection power supply drives the second blower to operate normally, and the first protection circuit is disconnected under the action of the second interlock switch.

[0081] Preferably, the switch module turns on the connection between the first inverter and the first blower through the first interlock switch, and disconnects the connection between the protection power supply and the first blower; or turns on the protection power supply to drive the first blower to operate, and disconnects the connection between the first inverter and the first blower.

[0082] Preferably, the switch module turns on the connection between the second inverter and the second blower through the first interlock switch, and disconnects the connection between the protection power supply and the second blower; or turns on the protection power supply to drive the second blower to operate, and disconnects the connection between the second inverter and the second blower.

[0083] An embodiment of the present invention further provides a distributed control system, which adopts the blower inverter fault protection circuit provided by any of the above embodiments.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A blower inverter fault protection circuit, characterized in that: The protection circuit includes: The first drive circuit comprises a power supply, a first frequency converter, a first switch module and a first blower connected in series in sequence, and is used to drive the first blower to operate through the first frequency converter; A second driving circuit comprises the power supply, a second frequency converter, a second switch module and a second blower connected in series in sequence, and is used to drive the second blower to operate through the second frequency converter; a first protection circuit, comprising a third switch module and a protection power supply connected in series with the first blower in sequence, for conducting the first protection circuit through the third switch module and driving the corresponding blower to operate normally through the protection power supply when the first inverter fails; and A second protection circuit includes a fourth switch module and the protection power supply which are sequentially connected in series with the second blower, and is used to conduct the second protection circuit through the fourth switch module and drive the corresponding blower to operate normally through the protection power supply when the second frequency converter fails; Wherein, the first switch module and the second switch module constitute a first interlocking switch, which is used to conduct the first drive branch or the second drive branch; the third switch module and the fourth switch module constitute a second interlocking switch, which is used to conduct the corresponding first protection branch or the second protection branch when the first drive branch or the second drive branch fails; The second interlock switch includes a third interlock branch and a fourth interlock branch; the third interlock branch is composed of a normally closed contact of a fifth AC contactor, a coil of a sixth AC contactor and a controller connected in series, and the normally open contact of the fifth AC contactor is connected to the first protection circuit; the fourth interlock branch is composed of a normally closed contact of a sixth AC contactor, a coil of a fifth AC contactor and a controller connected in series, and the normally open contact of the sixth AC contactor is connected to the second protection circuit; The second interlock switch also includes a third protection indication branch and a fourth protection indication branch; the third protection indication branch is composed of a coil of the first relay, a second relay normally closed contact of the second relay and a controller connected in series; the normally open contact of the first relay is connected to the third interlock branch, the normally closed contact is connected to the fourth interlock branch, and the third protection indication branch is connected in parallel with the third interlock branch; the fourth protection indication branch is composed of a coil of the second relay, a normally closed contact of the first relay and a controller connected in series; the normally open contact of the second relay is connected to the fourth interlock branch, the normally closed contact is connected to the third interlock branch, and the fourth protection indication branch is connected in parallel with the fourth interlock branch; wherein, when the third protection indication branch or the fourth protection indication branch is turned on, the controller controls the corresponding indicator light to light up; The first switch module in the first interlock switch includes a first drive branch and a first protection detection branch, and the second switch module includes a second drive branch and a second protection detection branch; the first drive branch is composed of a coil of the first AC contactor, a normally closed contact of the second AC contactor and a controller connected in series; the first protection detection branch is composed of a coil of the second AC contactor, a normally closed contact of the first AC contactor, a normally closed contact of the fourth AC contactor and a controller connected in series; the second drive branch is composed of a coil of the third AC contactor, a normally closed contact of the fourth AC contactor and a controller connected in series; the second protection detection branch is composed of a coil of the fourth AC contactor, a normally closed contact of the third AC contactor, a normally closed contact of the second AC contactor and a controller connected in series; wherein the normally open contact of the first AC contactor is connected to the first drive circuit; and the normally open contact of the third AC contactor is connected to the second drive circuit.

2. A blower inverter fault protection circuit according to claim 1, characterized in that: The first switch module includes a first drive indication branch composed of a third relay and a fourth relay; the second switch module includes a second drive indication branch composed of a fifth relay and a sixth relay; The first drive indication branch is composed of a coil of a third relay connected in parallel with a coil of a first AC contactor, a normally closed contact of the third relay connected to the first protection detection branch, a coil of a fourth relay connected in parallel with a coil of a second AC contactor, and a normally closed contact of the fourth relay connected to the first drive branch; The second drive indication branch is composed of a coil of a fifth relay connected in parallel with a coil of a third AC contactor, a normally closed contact of the fifth relay connected to the second protection detection branch, a coil of a sixth relay connected in parallel with a coil of a fourth AC contactor, and a normally closed contact of the sixth relay connected to the second drive branch; Wherein, when the first drive indication branch or the second drive indication branch is turned on, the controller controls the corresponding indicator light to light up.

3. A distributed control method, the method adopting the blower inverter fault protection circuit according to claim 1 or 2, comprising the following steps: Controlling the first frequency converter to drive the first blower to operate by the switch module or controlling the second frequency converter to drive the second blower to operate by the switch module; When the first frequency converter fails, the first protection circuit is turned on through the third switch module to protect the power supply to drive the first blower to operate normally, and the second protection circuit is turned off under the action of the second interlock switch; When the second frequency converter fails, the second protection circuit is turned on through the fourth switch module, and the protection power supply drives the second blower to operate normally. Under the action of the second interlock switch, the first protection circuit is disconnected.

4. A distributed control method according to claim 3, further comprising the following steps: The switch module drives the connection between the first frequency converter and the first blower through the first interlock switch, and disconnects the connection between the protection power supply and the first blower; or The protection power supply is turned on to drive the first blower to operate, and the connection between the first inverter and the first blower is disconnected.

5. A distributed control method according to claim 3, further comprising the following steps: The switch module drives the connection between the second frequency converter and the second blower through the first interlock switch, and disconnects the connection between the protection power supply and the second blower; or The protection power supply is turned on to drive the second blower to operate, and the connection between the second frequency converter and the second blower is disconnected.

6. A distributed control system, characterized in that: The control system includes a blower inverter fault protection circuit as described in claim 1 or 2.

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