Circuit, device and system for timed release of accumulated charges

Abstract

The utility model relates to a circuit, a device and a system for timed release of accumulated charges. The circuit comprises a PLC controller, a relay and a wiring terminal strip. The wiring terminal strip is connected with a measuring loop common line, a signal line and a grounding copper bar of the DCS system terminal board; the PLC comprises a relay control switch and a signal line transmission switch; the signal line transmission switch is connected with a terminal of a corresponding signal line in the wiring terminal strip; the PLC presets a timing driving program, drives the signal line transmission switch to be closed in a timing manner, and sends a switching signal to the DCS terminal board through the signal line, so that the DCS locks temperature display according to the switching signal; and after the signal line transmission switch is closed for a preset time, the PLC drives the relay control switch to be closed, so that the common line of the measurement loop releases accumulated charges to the ground. When the temperature accumulation charge of the generator is released, the temperature value can be displayed. And manual discharging is not needed, so that the workload of personnel is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of thermal control, and in particular relates to a circuit, a device and a system for timing release of accumulated charges. Background Art

[0002] In the operation of thermal power units, generator temperature measurement plays a very important role in ensuring the safety and stable operation of the generator and optimizing operation management. Thermistor is a device used to measure temperature based on the principle that the resistivity of a material changes with temperature. When the temperature changes, the resistance value generated by the thermal resistor also changes. This change can be used to infer the change in temperature by measuring the resistance value. The working principle of thermistor is based on the principle of thermoelectric effect and temperature coefficient of resistivity. In thermistor, a resistor is formed by a thin wire resistance material. When the resistor is heated, the resistance value increases with the increase in temperature. This phenomenon is called positive temperature coefficient, which is a phenomenon that the resistivity is proportional to the temperature. In the measurement process of thermistor, the thermal resistor needs to be connected to a precise constant current source, which will generate a voltage signal through the thermal resistor. By measuring the voltage and current, the resistance value of the thermal resistor can be calculated. Since the resistance value is proportional to the temperature, the current temperature can be inferred from the calculated resistance value.

[0003] In the temperature measurement of thermal power plants, the primary element of the thermal resistor is introduced into the distributed control system (DCS) through the signal cable. The DCS sampling terminal board provides a 15V DC power supply. The sampling signal is converted into a 1V-5V DC sampling voltage through the bridge circuit and finally sent to the analog input card for real-time display in the DCS system.

[0004] However, due to the special installation position of the generator, the primary temperature element of the generator is prone to accumulate charges due to electromagnetic induction, insulation degradation or contamination by impurities. When the accumulated charges accumulate to a certain extent, it will cause abnormal temperature measurement. Generally, the displayed temperature will be 5-10 degrees Celsius higher than the actual temperature. This is a common phenomenon in generator temperature measurement. It is very difficult to deal with such problems. The temperature element is installed inside the generator and is usually impossible to repair. Generally, it will be disassembled and inspected once an overhaul cycle. Therefore, it is necessary to discharge the measurement circuit to the ground regularly. However, due to the large number of temperature measurement points and short discharge cycle of the generator, it brings a large workload to the thermal workers, and frequent manual discharge will also bring safety hazards. Utility Model Content

[0005] In order to make up for the defects of the prior art, the utility model provides a circuit, a device and a system for timely releasing the accumulated charge.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0007] In a first aspect, a circuit for timing release of accumulated charge is provided, comprising:

[0008] PLC controller, relay and terminal block, there are multiple relays;

[0009] The terminal block is connected to the measurement circuit common line, signal line and grounding copper bar of the DCS system terminal board. The measurement circuit common line is the common line of all measurement circuits for measuring the generator temperature.

[0010] One end of the relay is connected to the terminal corresponding to the common line of the measuring circuit in the wiring terminal block; the other end is connected to the terminal corresponding to the grounding copper busbar in the wiring terminal block;

[0011] The PLC controller includes a relay control switch and a signal line transmission switch, and the relay control switch and the signal line transmission switch are in a disconnected state when the PLC controller is not in action;

[0012] The signal line transmission switch is connected to the terminal corresponding to the signal line in the wiring terminal block;

[0013] The PLC controller presets a timing drive program, which timing drives the signal line transmission switch to close, and sends a switch signal to the DCS system terminal board through the signal line, so that the DCS system locks the temperature display according to the switch signal;

[0014] After the signal line transmission switch is closed for a preset time, the PLC controller drives the relay to control the switch to close, so that the common line of the measurement loop releases the accumulated charge to the ground.

[0015] Furthermore, the circuit also includes:

[0016] Safety resistor;

[0017] The safety resistor is set between the relay and the terminal block.

[0018] Furthermore, the circuit also includes:

[0019] Air switch;

[0020] The air switch is connected to the power supply after the DCS system switches to supply power to the PLC controller.

[0021] Furthermore, the air switch has a live wire terminal and a neutral wire terminal;

[0022] The relay has a first relay coil terminal and a second relay coil terminal;

[0023] The first relay coil terminal is connected to the neutral terminal;

[0024] One end of the relay control switch is connected to the live wire end, and the other end is connected to the second relay coil terminal.

[0025] Furthermore, one relay corresponds to four measuring points for measuring the temperature of the generator, and the number of relays and the number of terminal blocks are determined according to the number of measuring points.

[0026] In a second aspect, a device for timely releasing accumulated charge is provided, comprising:

[0027] A control cabinet and a circuit for timed release of accumulated charge in the first aspect;

[0028] The PLC controller, relay, terminal block, safety resistor and air switch in the circuit for timed release of accumulated charge are all installed inside the control cabinet.

[0029] Furthermore, the dimensions of the control cabinet are 600 mm in length, 300 mm in width and 800 mm in height.

[0030] In a third aspect, a system for timely releasing accumulated charge is provided, comprising:

[0031] DCS system terminal cabinet and the device for timing release of accumulated charge of the second aspect;

[0032] The control cabinet of the device for timing release of accumulated charge is installed near the terminal cabinet of the DCS system;

[0033] The DCS system terminal board is installed inside the DCS system terminal cabinet.

[0034] Beneficial effects achieved by the utility model:

[0035] The PLC controller uses an internal preset timing driver to control the timing of the signal line transmission switch closure. When the signal line transmission switch is on, it will send a switch signal to the DCS system terminal board through the signal line. The DCS system will lock the currently displayed temperature value based on the switch signal; after the signal line transmission switch is closed for a preset time, the control relay controls the switch closure, so that the relay is turned on, and the common line of the measurement circuit releases the accumulated charge to the ground. When the accumulated charge of the generator temperature is released, the temperature value can be displayed. No manual discharge is required, which reduces the workload of personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The circuit structure diagram of the circuit for timely releasing the accumulated charge of the utility model is shown in FIG. DETAILED DESCRIPTION

[0037] The utility model is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the utility model, and cannot be used to limit the protection scope of the utility model.

[0038] like Figure 1 As shown, the embodiment of the utility model provides a circuit for timing release of accumulated charge, comprising:

[0039] PLC controller 101, relay 102 and terminal block 103, there are multiple relays;

[0040] The terminal block 103 is connected to the common line of the measurement circuit, the signal line and the grounding copper bar of the DCS system terminal board. The common line of the measurement circuit is the common line of all measurement circuits for measuring the temperature of the generator;

[0041] One end of the relay 102 is connected to a terminal corresponding to the common line of the measurement circuit in the wiring terminal block 103; the other end is connected to a terminal corresponding to the grounding copper bus in the wiring terminal block 103;

[0042] The PLC controller 101 includes a relay control switch Q1 and a signal line transmission switch Q2, and the relay control switch Q1 and the signal line transmission switch Q2 are in an off state when the PLC controller 101 is not in action;

[0043] The signal line transmission switch Q2 is connected to the terminal corresponding to the signal line in the wiring terminal block 103;

[0044] The PLC controller 101 presets a timing driving program, timing driving the signal line transmission switch Q2 to close, and sends a switch signal to the DCS system terminal board through the signal line, so that the DCS system locks the temperature display according to the switch signal;

[0045] After the signal line transmission switch Q2 is closed for a preset time, the PLC controller 101 drives the relay control switch Q1 to close, so that the common line of the measurement loop releases the accumulated charge to the ground.

[0046] Specifically, the relay control switch Q1 and the signal line transmission switch Q2 can be MOS tubes. The PLC controller 101 controls the signal line transmission switch Q2 to close in a timely manner through an internal preset timing driver. When Q2 is closed, a switch signal will be sent to the DCS system terminal board through the signal line. The DCS system will lock the currently displayed temperature value according to the switch signal; after Q2 is closed for a preset time (for example, 1 second), the relay control switch Q1 is driven to close, so that the relay is turned on, and the common line of the measurement circuit releases the accumulated charge to the ground. Therefore, when the accumulated charge of the generator temperature is released, the temperature value can be displayed. After the accumulated charge is released, the relay control switch Q1 and the signal line transmission switch Q2 are in the open state again.

[0047] The circuit also includes: a safety resistor 104;

[0048] The safety resistor 104 is disposed between the relay 102 and the terminal block 103 , and the resistance of the safety resistor 104 is 1K ohm.

[0049] The circuit further includes: an air switch 105;

[0050] The air switch 105 is connected to the power source after the DCS system switches, and supplies power to the PLC controller 101 .

[0051] The air switch 105 has a live wire L terminal and a neutral wire N terminal;

[0052] The relay 102 has a first relay coil terminal A1 and a second relay coil terminal A2;

[0053] The first relay coil terminal A1 is connected to the neutral line N terminal;

[0054] One end of the relay control switch Q1 is connected to the live wire L, and the other end is connected to the second relay coil terminal A2.

[0055] It should be noted that one relay corresponds to four measuring points for measuring the temperature of the generator, and the number of relays and the number of terminal blocks are determined according to the number of measuring points.

[0056] Combined with the above Figure 1 The embodiment shown in the figure, the embodiment of the utility model provides a device for timely releasing accumulated charge, comprising:

[0057] Control cabinet and Figure 1 A circuit for timely releasing the accumulated charge in the embodiment;

[0058] The PLC controller, relay, terminal block, safety resistor and air switch in the circuit for the timed release of accumulated charge are all installed inside the control cabinet;

[0059] The dimensions of the control cabinet are 600mm in length, 300mm in width and 800mm in height.

[0060] Combined with the above Figure 1 The embodiment shown in the figure, the embodiment of the utility model provides a system for timely releasing accumulated charge, comprising:

[0061] DCS system terminal cabinet and device for timing release of accumulated charge;

[0062] The control cabinet of the device for timing release of accumulated charge is installed near the terminal cabinet of the DCS system, so as to facilitate wiring;

[0063] The DCS system terminal board is installed inside the DCS system terminal cabinet.

[0064] Those skilled in the art will appreciate that the embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may be in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0065] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0066] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0067] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0068] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A circuit for releasing accumulated charge at a fixed time, characterized in that: include: PLC controller, relay and terminal block, wherein there are multiple relays; The terminal block is connected to the measurement circuit common line, signal line and grounding copper bar of the DCS system terminal board, and the measurement circuit common line is the common line of all measurement circuits for measuring the temperature of the generator; One end of the relay is connected to a terminal in the wiring terminal block corresponding to the common line of the measurement circuit; the other end is connected to a terminal in the wiring terminal block corresponding to the grounding copper busbar; The PLC controller includes a relay control switch and a signal line transmission switch, and the relay control switch and the signal line transmission switch are in an off state when the PLC controller is not in action; The signal line transmission switch is connected to the terminal corresponding to the signal line in the wiring terminal row; The PLC controller presets a timing driving program, timingly drives the signal line transmission switch to close, and sends a switch signal to the DCS system terminal board through the signal line, so that the DCS system locks the temperature display according to the switch signal; After the signal line transmission switch is closed for a preset time, the PLC controller drives the relay control switch to close, so that the common line of the measurement loop releases the accumulated charge to the ground.

2. The circuit for timely releasing accumulated charge according to claim 1, characterized in that: The circuit further comprises: Safety resistor; The safety resistor is arranged between the relay and the wiring terminal block.

3. The circuit for timely releasing the accumulated charge according to claim 2, characterized in that: The circuit further comprises: Air switch; The air switch is connected to the power supply after the DCS system switches to supply power to the PLC controller.

4. The circuit for timely releasing the accumulated charge according to claim 3, characterized in that: The air switch has a live wire terminal and a neutral wire terminal; The relay has a first relay coil terminal and a second relay coil terminal; The first relay coil terminal is connected to the neutral line terminal; One end of the relay control switch is connected to the live wire end, and the other end is connected to the second relay coil terminal.

5. The circuit for timely releasing the accumulated charge according to any one of claims 1 to 4, characterized in that: One relay corresponds to four measuring points for measuring the temperature of the generator, and the number of the relays and the number of the terminal blocks are determined according to the number of the measuring points.

6. A device for timely releasing accumulated charge, characterized in that: include: A control cabinet and a circuit for timely releasing the accumulated charge as described in any one of claims 1 to 5; The PLC controller, relay, terminal block, safety resistor and air switch in the circuit for timing release of accumulated charge are all installed inside the control cabinet.

7. The device for timed release of accumulated charge according to claim 6, characterized in that: The dimensions of the control cabinet are 600 mm in length, 300 mm in width and 800 mm in height.

8. A system for timely releasing accumulated charge, characterized in that: include: DCS system terminal cabinet and the device for timely releasing the accumulated charge as claimed in claim 6 or 7; The control cabinet of the device for timing release of accumulated charge is installed near the terminal cabinet of the DCS system; A DCS system terminal board is installed inside the DCS system terminal cabinet.

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