Frequency converter control structure for waste gas treatment

Abstract

The utility model discloses a frequency converter control structure for waste gas treatment, which comprises a plurality of frequency converters, output ends of the frequency converters are connected with a plurality of fans in a one-to-one correspondence manner, and the frequency converters are used for controlling operation of the corresponding fans; the plurality of start-stop control modules are in electric connection and / or communication connection with the remote programmable logic controller; the data sampling modules are arranged in one-to-one correspondence with the frequency converters; wherein the data sampling modules are connected in series through RS485 (Recommended Standard 485); the remote programmable logic controller is connected with the data sampling module at the most front end or the most tail end through an RS485 bus, so that acquisition of operation signals and fault signals of all the frequency converters is realized, and frequency control of all the frequency converters is realized; and all the frequency converters realize frequency feedback to the remote programmable logic controller through an RS485 bus and a data sampling module.

Description

Technical Field

[0001] The utility model relates to the technical field of waste gas treatment, and particularly relates to a frequency converter control structure for waste gas treatment. Background Technique

[0002] In the waste gas treatment system of the photovoltaic industry, a large number of fans are required, and the fans need to be frequency-controlled, so the frequency converter is essential. The frequency converter needs to be locally (local cabinet buttons) and remotely (PLC) controlled.

[0003] In some large photovoltaic factories, there are many sets of waste gas systems, and the number of fans can reach several hundred. Several hundred frequency converters need to be locally and remotely controlled. In this way, the PLC points occupied by the fans are very many, the PLC and cabinet costs will be very high, and the signal lines to be connected are extremely complicated, increasing the wiring workload of on-site workers. In addition, with the development of the industry, the owner's requirements for the data that needs to be remotely transmitted by the frequency converter are getting higher and higher, and the types of requirements are getting more and more. The traditional hard-wired control can no longer meet the requirements. Summary of the Utility Model

[0004] In view of this, the embodiment of the utility model provides a frequency converter control structure for waste gas treatment to solve the problems that the wiring method of the existing waste gas treatment system occupies too many PLC points, the wiring work is complicated, and the existing wiring method cannot meet the owner's requirements for the backhaul data.

[0005] The embodiment of the utility model provides a frequency converter control structure for waste gas treatment, including:

[0006] A number of frequency converters, the output ends of which are respectively connected to a number of fans in one-to-one correspondence, for controlling the operation of the corresponding fans;

[0007] A number of start-stop control modules, electrically connected and / or communicatively connected to a remote programmable logic controller;

[0008] A data sampling module, which is respectively arranged corresponding to each frequency converter; wherein, each data sampling module is serially connected through RS485;

[0009] A remote programmable logic controller, which is connected to the data sampling module at the front end or the end through an RS485 bus, so as to realize the acquisition of the operation signals and fault signals of all frequency converters, and realize the frequency control of all frequency converters; all frequency converters realize the frequency feedback to the remote programmable logic controller through the RS485 bus and the data sampling module.

[0010] Optionally, the start-stop control module includes:

[0011] The knob 1-S1 is used to switch on the local start loop or the remote start loop; the remote programmable logic controller is connected to the wiring terminal of the remote start loop corresponding to the knob 1-S1.

[0012] Among them, the local start loop includes:

[0013] The start button 1-SB1, the stop button 1-SB2 and the first relay K1; the first relay K1 is controlled by the start button 1-SB1 and the stop button 1-SB2 to switch between the powered-on and powered-off states, so as to realize the start and stop of the frequency converter.

[0014] The remote start loop includes:

[0015] The second relay K2, whose powered-on and powered-off states are controlled by the first output terminal KP1 and the second output terminal KP2 of the remote programmable logic controller, so as to realize the start and stop of the frequency converter.

[0016] Optionally, it further includes:

[0017] The running indicator light, whose first end is connected to the first relay output terminal of the frequency converter, the second end of the running indicator light is connected to the lamp connection terminal of the start button 1-SB1, and the third end of the running indicator light is connected to the output terminal of the start-stop control module;

[0018] The fault indicator light, one end of which is connected to the second relay output terminal of the frequency converter, and the other end is connected to the output terminal of the start-stop control module.

[0019] Optionally, the data sampling module includes:

[0020] The current detection module is used to send the running current information of the frequency converter to the remote programmable logic controller.

[0021] Optionally, the data sampling module further includes:

[0022] The temperature detection module is arranged inside the frequency converter; the temperature detection module is used to send the internal temperature of the frequency converter to the remote programmable logic controller.

[0023] Optionally, the data sampling module further includes:

[0024] The tachometer is used to send the speed of the frequency converter to the remote programmable logic controller; when the frequency converter is in the torque control mode, the remote programmable logic controller calculates and obtains the torque information of the frequency converter according to the speed of the frequency converter, the power of the frequency converter and the number of motor pole pairs.

[0025] Optionally, the third end of the running indicator light, the other end of the fault indicator light, and the output terminal of the start-stop control module are connected to the zero line.

[0026] The beneficial effects of the utility model:

[0027] The frequency converter control structure for waste gas treatment provided by this embodiment not only reduces the consumption of electrical materials, but also increases the reading of more parameters. The operation signal, fault signal, frequency control and frequency feedback of the frequency converter all enter the PLC through the 485 communication method. Through the wiring method provided by the present utility model, 2 relays (K3, K4) can be saved for each frequency converter. For the PLC, 1 AO, 1 AI and 2 DI channels can be saved, thus saving the cost of the PLC. In terms of wiring, the conventional control scheme needs to consume 4 signals to connect the above signals, while this embodiment only needs 1 wire to connect in series. Through the 485 communication of each frequency converter, the operating current, transmission temperature, torque and other parameters of the frequency converter can be additionally read, meeting more requirements for the fan control in the waste gas industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The features and advantages of the present utility model will be more clearly understood by referring to the accompanying drawings. The drawings are schematic and should not be construed as any limitation to the present utility model. In the drawings:

[0029] Figure 1 Shows the electrical wiring diagram of the frequency converter in the conventional control scheme;

[0030] Figure 2 Shows the signal connection relationship between the frequency converter and the PLC in the conventional control scheme;

[0031] Figure 3 Shows a block diagram of the electrical wiring structure of a frequency converter in an embodiment of the present utility model;

[0032] Figure 4 Shows the electrical wiring diagram of a frequency converter in an embodiment of the present utility model;

[0033] Figure 5 Shows the signal connection relationship between a frequency converter and the PLC in an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0035] It should be understood that the modules and control methods adopted in this patent are all prior arts, and their conventional functions are applied. This patent is directed to the improvement of the circuit and wiring method.

[0036] Figure 1 and Figure 2 is the conventional control wiring scheme of the frequency converter. To better understand the working process, its working principle is described as follows:

[0037] Start-stop control of the frequency converter:

[0038] It is divided into local button control and remote PLC control. When the knob 1-S1 is turned to the local position, the start button 1-SB1 and the stop button 1-SB2 are used to control the energization and de-energization of the K1 relay, thereby controlling the start and stop of the frequency converter. When the knob 1-S1 is turned to the remote position, the relay output points KP1 and KP2 of the PLC are used to control the energization and de-energization of the K2 relay, thereby controlling the start and stop of the frequency converter.

[0039] Digital quantity signal reading of the frequency converter:

[0040] The running and fault signals are output through the relay output terminals on the frequency converter. Since the number of relay terminals on the frequency converter is limited, when both the running and fault signals are required for the cabinet door indicator lights and to enter the PLC, it is necessary to add an intermediate relay to increase the contact output to achieve this.

[0041] Frequency control and feedback of the frequency converter:

[0042] The frequency control and feedback are respectively achieved through the wiring terminals on the frequency converter.

[0043] The embodiment of the present invention provides a frequency converter control structure for waste gas treatment, as Figures 3 to 5 shown, including: a plurality of frequency converters, whose output terminals are respectively connected to a plurality of fans in one-to-one correspondence for controlling the operation of the corresponding fans; a plurality of start-stop control modules, electrically connected and / or communicatively connected to a remote programmable logic controller; a data sampling module, provided in one-to-one correspondence with each frequency converter; wherein, each data sampling module is serially connected through RS485; the remote programmable logic controller is connected to the data sampling module at the frontmost or rearmost end through the RS485 bus, so as to realize the acquisition of the running signals and fault signals of all frequency converters, and realize the frequency control of all frequency converters; all frequency converters realize the frequency feedback to the remote programmable logic controller through the RS485 bus and the data sampling module.

[0044] The running indicator light, its first end is connected to the first relay output terminal of the frequency converter, the second end of the running indicator light is connected to the lamp connection terminal of the start button 1-SB1, and the third end of the running indicator light is connected to the output terminal of the start-stop control module. The fault indicator light, one end of it is connected to the second relay output terminal of the frequency converter, and the other end of it is connected to the output terminal of the start-stop control module.

[0045] Connect the running and fault indicator lights directly to the relay output terminals on the frequency converter, and the signals input to the PLC are realized by 485 communication. As Figure 4 shown, terminals 29 and 30 of the frequency converter are used as the AB connection terminals of RS485 to achieve communication connection with the remote PLC.

[0046] The frequency converter control structure for waste gas treatment provided by this embodiment not only reduces the consumption of electrical materials, but also increases the reading of more parameters. The running signal, fault signal, frequency control and frequency feedback of the frequency converter all enter the PLC through 485 communication. Comparing Figure 1 and Figure 4 it can be seen that in the wiring method of the present utility model, 2 relays (K3, K4) can be saved for each frequency converter. For the PLC, 1AO, 1AI, and 2 DI channels can be saved, thus saving the cost of the PLC. In terms of wiring, the conventional control scheme needs to consume 4 signals to connect the above signals, while only 1 wire is needed for series connection in this embodiment. Through 485 communication for each frequency converter, parameters such as the running current, drive temperature, and torque of the frequency converter can be additionally read, meeting more requirements for the fan control in the waste gas industry.

[0047] Although the embodiments of the present utility model have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A frequency converter control structure for exhaust gas treatment, characterized in that: include: A plurality of frequency converters, whose output ends are connected to a plurality of fans in a one-to-one correspondence, for controlling the operation of the corresponding fans; A plurality of start-stop control modules are electrically and / or communicatively connected to the remote editable logic controller; A data sampling module is provided corresponding to each of the frequency converters; wherein each of the data sampling modules is connected to each other via RS485 serial connection; The remote programmable logic controller is connected to the data sampling module at the front end or the end through the RS485 bus, so as to collect the operation signals and fault signals of all the frequency converters and realize the frequency control of all the frequency converters; all the frequency converters realize frequency feedback to the remote programmable logic controller through the RS485 bus and the data sampling module.

2. The inverter control structure for exhaust gas treatment according to claim 1, characterized in that: The start-stop control module comprises: Knob 1-S1 is used to switch on the local start circuit or the remote start circuit; the remote editable logic controller is connected to the wiring terminal of the remote start circuit corresponding to the knob 1-S1; Wherein, the local start loop includes: A start button 1-SB1, a stop button 1-SB2 and a first relay K1; the first relay K1 is controlled by the start button 1-SB1 and the stop button 1-SB2 to switch between power on and power off states, thereby realizing the start and stop of the frequency converter; The remote start circuit comprises: The second relay K2 is controlled by the first output terminal KP1 and the second output terminal KP2 of the remote programmable logic controller to switch its power on / off state, thereby realizing the start and stop of the frequency converter.

3. The inverter control structure for exhaust gas treatment according to claim 2, characterized in that: Also includes: An operation indicator light, a first end of which is connected to the first relay output terminal of the inverter, a second end of which is connected to the light receiving terminal of the start button 1-SB1, and a third end of which is connected to the output end of the start-stop control module; A fault indicator light, one end of which is connected to the second relay output terminal of the inverter, and the other end of which is connected to the output end of the start-stop control module.

4. The inverter control structure for exhaust gas treatment according to claim 1, characterized in that: The data sampling module comprises: The current detection module is used to send the operating current information of the inverter to the remote programmable logic controller.

5. The inverter control structure for exhaust gas treatment according to claim 1, characterized in that: The data sampling module also includes: A temperature detection module is arranged inside the frequency converter; the temperature detection module is used to send the internal temperature of the frequency converter to the remote programmable logic controller.

6. The inverter control structure for exhaust gas treatment according to claim 1, characterized in that: The data sampling module also includes: A tachometer is used to send the speed of the inverter to the remote programmable logic controller; when the inverter is in a torque control mode, the remote programmable logic controller calculates and obtains the torque information of the inverter based on the speed of the inverter, the power of the inverter and the number of motor pole pairs.

7. The inverter control structure for exhaust gas treatment according to claim 3, characterized in that: The third end of the operation indicator light, the other end of the fault indicator light, and the output end of the start-stop control module are connected to the neutral line.

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