A multi-parameter monitoring and automatic control device for power plant

Abstract

The utility model discloses a kind of power plant multi-parameter monitoring automatic control device, including multiple sensors, signal conditioning circuit, main control module, alarm circuit, execution module, anti-interference power supply circuit and isolation transmission unit.The utility model is through pressure, temperature, harmonic, four kinds of special sensors of fuel component Comprehensive collection power plant core operating parameter, in combination with the filter amplification of signal conditioning circuit and the isolation transmission design of photoelectric coupler, substantially improve parameter measurement accuracy, effectively solve the problem of traditional device front-end conditioning deficiency, easily disturbed;Meanwhile, multi-link filtering and clamping protection of anti-interference power supply circuit, electromagnetic shielding and dust heat dissipation design of the matching stainless steel protective shell, ensure that device is stable under the complex working condition of high dust, high electromagnetic interference Run, in addition to cooperate the hierarchical warning function of alarm circuit, without manual intervention can quickly respond to abnormality, reduce operation and maintenance cost and risk.

Description

Technical Field

[0001] This utility model relates to the field of power plant control technology, and in particular to a multi-parameter monitoring and automatic control device for power plants. Background Technology

[0002] In the process of power plant production and operation, the accurate monitoring and automatic control of multiple parameters such as boiler pressure, turbine temperature, harmonic content, and fuel composition are the core links to ensure power generation efficiency, equipment safety and operational stability. Although existing power plant multi-parameter monitoring and automatic control devices have been widely used, they still have obvious shortcomings in actual operation and are difficult to adapt to the complex operating environment of power plants with high dust, high electromagnetic interference and frequent fluctuations in operating conditions.

[0003] Specifically, the shortcomings of existing devices are mainly reflected in the following aspects: 1. Insufficient front-end conditioning capability in the signal acquisition stage, and the traditional single-ended sampling method is easily affected by grounding noise; 2. Imperfect anti-interference design, power supply ripple, transient surge and signal transmission attenuation interference further aggravate measurement deviation; In view of the above, this application proposes a power plant multi-parameter monitoring automatic control device. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a multi-parameter monitoring and automatic control device for power plants.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A power plant multi-parameter monitoring automatic control device includes multiple sensors, a signal conditioning circuit, a main control module, an alarm circuit, an execution module, an anti-interference power supply circuit, and an isolation transmission unit;

[0007] The signal conditioning circuit is electrically connected to the main control module through an isolation transmission unit, the signal conditioning circuit is electrically connected to multiple sensors, the execution module is electrically connected to the main control module and the anti-interference power supply circuit, and the main control module is electrically connected to the alarm circuit.

[0008] Preferably, the signal conditioning circuit includes a comparator U1. Pin 1 of the comparator U1 is electrically connected to one end of a resistor R1. Pin 2 of the comparator U1 is electrically connected to one end of a resistor R2, one end of a resistor R4, and one end of a resistor R5. The other end of resistor R5 is grounded. The other end of resistor R4 and pin 4 of the comparator U1 are both electrically connected to a 5V voltage. The other end of resistor R2 is electrically connected to the other end of resistor R1. The other end of resistor R2 is also electrically connected to one end of resistor R3 and one end of capacitor C1. The other end of capacitor C1 is grounded. Pin 3 of the comparator U1 is electrically connected to one end of capacitor C2. The other end of capacitor C2 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to pin 1 of the comparator U1.

[0009] Preferably, the anti-interference power supply circuit includes an operational amplifier U2. Pin 1 of the operational amplifier U2 is electrically connected to one end of a capacitor C4. The other end of capacitor C4 is electrically connected to the cathode of diode D2, the anode of diode D1, one end of resistor R8, and one end of resistor R7. The other end of resistor R8, the cathode of diode D1, and the anode of diode D2 are all grounded. Pin 2 of the operational amplifier U2 is electrically connected to one end of resistor R12, the other end of which is grounded. Pin 5 of the operational amplifier U2 is electrically connected to one end of capacitor C3. The other end of capacitor C3 is connected to the operational amplifier... Pin 2 of operational amplifier U2 is electrically connected to the positive terminal of diode D3 and one end of capacitor C5. The negative terminal of diode D3 is electrically connected to one end of resistor R11. The other end of resistor R11 is electrically connected to pin 2 of operational amplifier U2. Pin 4 of operational amplifier U2 is electrically connected to one end of resistor R9. The other end of resistor R9 is electrically connected to the other end of capacitor C5. Pin 3 of operational amplifier U2 is electrically connected to one end of resistor R10. The other end of resistor R10 and pin 4 of operational amplifier U2 are both electrically connected to a 5V voltage.

[0010] Preferably, the alarm circuit includes an alarm K1. Pin 2 of the alarm K1 is electrically connected to pin 1 of transistor Q1 and the negative terminal of diode D4. The positive terminal of diode D4 is electrically connected to one end of resistor R13, and the other end of resistor R13 is electrically connected to pin 1 of the alarm K1. Pin 1 of the alarm K1 is electrically connected to the positive terminal of diode D5 and pin 1 of transistor Q2. The negative terminal of diode D5 is electrically connected to the positive terminal of diode D6. Pin 3 of transistor Q2 is electrically connected to one end of resistor R15, and the other end of resistor R15 is electrically connected to the negative terminal of diode D6. Pin 3 of transistor Q1 is electrically connected to one end of resistor R14 and pin 2 of transistor Q2, and pin 2 of transistor Q1 is electrically connected to the other end of resistor R14.

[0011] Preferably, the multi-sensor includes a pressure sensor, a temperature sensor, a harmonic sensor, and a fuel composition sensor. The pressure sensor is used to collect boiler pressure parameters, the temperature sensor is used to collect turbine temperature parameters, the harmonic sensor is used to collect grid harmonic content parameters, and the fuel composition sensor is used to collect fuel composition percentage parameters. The signal output terminals of each sensor are electrically connected to the other end of resistor R3 in the signal conditioning circuit.

[0012] Preferably, the isolation transmission unit adopts an optocoupler isolation transmission method. The input terminal of the optocoupler is electrically connected to pin 3 of comparator U1 in the signal conditioning circuit, the output terminal of the optocoupler is electrically connected to the signal input terminal of the main control module, and the power supply terminal of the optocoupler is electrically connected to the power supply terminal of the anti-interference power supply circuit.

[0013] Preferably, the main control module includes a microcontroller chip, a storage module, and a communication module. The storage module is electrically connected to the storage interface of the microcontroller chip and is used to store the acquisition thresholds and historical data of multiple parameters. The communication module is electrically connected to the communication interface of the microcontroller chip and adopts RS485 communication to realize data interaction with the power plant's central monitoring system. The execution module includes a relay drive circuit and a frequency converter drive circuit. The relay drive circuit is used to control the on / off state of the power plant's switching equipment, and the frequency converter drive circuit is used to adjust the operating frequency of the power plant's motor equipment. The control terminals of both the relay drive circuit and the frequency converter drive circuit are electrically connected to the control output terminal of the main control module.

[0014] Preferably, the automatic control device also includes a protective housing made of stainless steel. The inner wall of the protective housing is provided with an electromagnetic shielding layer. Multiple sensors, signal conditioning circuits, main control modules, alarm circuits, execution modules, anti-interference power supply circuits, and isolation transmission units are all installed inside the protective housing. The surface of the protective housing is provided with heat dissipation holes, and dustproof nets are installed at the heat dissipation holes.

[0015] Compared with existing technologies, the beneficial effects of this utility model are:

[0016] 1. The device is equipped with four types of dedicated sensors: pressure, temperature, harmonics, and fuel composition. These sensors collect key operating parameters of the power plant, such as boiler pressure, turbine temperature, grid harmonic content, and fuel composition ratio. Compared with the single or limited parameter collection capabilities of traditional devices, this device can comprehensively cover the core indicators affecting efficiency and safety in the power generation process, providing complete data support for subsequent monitoring and control and avoiding operational risks caused by incomplete parameter monitoring.

[0017] 2. By setting up the signal conditioning circuit, DC offset and low-frequency noise in the original sensor signal can be effectively filtered out, weak signals can be amplified, and the problem of "insufficient front-end conditioning capability" of traditional devices can be solved. In addition, the optocoupler used in conjunction with the isolation transmission unit cuts off the electrical connection of the signal transmission circuit through "electric-optical-electric" conversion, completely isolating grounding noise and common-mode interference in the strong electromagnetic environment of the power plant, avoiding signal transmission attenuation and distortion, significantly reducing measurement deviation, and ensuring the accuracy of parameter acquisition.

[0018] 3. By setting up an anti-interference power supply circuit, power ripple and transient surges are effectively suppressed, providing stable and interference-free voltage for each module and avoiding power supply noise from affecting the operation of the device. In addition, the stainless steel protective shell combined with the inner wall electromagnetic shielding layer can weaken external electromagnetic interference and block the intrusion of high dust. The heat dissipation holes of the shell and the dustproof mesh work together to take into account both heat dissipation and dust protection, solving the defect of traditional devices that are "difficult to adapt to high dust and high electromagnetic interference environments" and improving the long-term operational stability of the device.

[0019] 4. Through the alarm circuit settings, it is possible to achieve graded responses of "severe abnormal high decibel alarm" and "minor early warning intermittent alarm", so that personnel can be informed in a timely manner and take action.

[0020] This invention comprehensively collects core operating parameters of power plants using four types of dedicated sensors: pressure, temperature, harmonics, and fuel composition. Combined with the filtering and amplification of the signal conditioning circuit and the isolation transmission design of the optocoupler, it significantly improves the accuracy of parameter measurement and effectively solves the problems of insufficient front-end conditioning and susceptibility to interference in traditional devices. At the same time, the multi-stage filtering and clamping protection of the anti-interference power supply circuit, along with the electromagnetic shielding and dustproof heat dissipation design of the stainless steel protective shell, ensures stable operation of the device under complex conditions of high dust and high electromagnetic interference. In addition, the alarm circuit's graded warning function allows for rapid response to anomalies without manual intervention, reducing operation and maintenance costs and risks. Attached Figure Description

[0021] Figure 1 This is a block diagram of a multi-parameter monitoring and automatic control device for power plants proposed in this utility model;

[0022] Figure 2 This is a circuit diagram of a signal conditioning circuit in a power plant multi-parameter monitoring automatic control device proposed in this utility model;

[0023] Figure 3 This is a circuit diagram of an anti-interference power supply circuit in a power plant multi-parameter monitoring automatic control device proposed in this utility model.

[0024] Figure 4 This invention relates to a circuit diagram of an alarm circuit in a power plant multi-parameter monitoring automatic control device. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0026] Reference Figure 1-4 A power plant multi-parameter monitoring automatic control device includes multiple sensors, signal conditioning circuit, main control module, alarm circuit, execution module, anti-interference power supply circuit and isolation transmission unit;

[0027] The automatic control device also includes a protective housing made of stainless steel. The inner wall of the protective housing is provided with an electromagnetic shielding layer. Multiple sensors, signal conditioning circuits, main control modules, alarm circuits, execution modules, anti-interference power supply circuits, and isolation transmission units are all installed inside the protective housing. The surface of the protective housing has heat dissipation holes, and dustproof nets are installed at the heat dissipation holes.

[0028] The signal conditioning circuit is electrically connected to the main control module through the isolation transmission unit, the signal conditioning circuit is electrically connected to the multi-sensor, the execution module is electrically connected to the main control module and the anti-interference power supply circuit, and the main control module is electrically connected to the alarm circuit.

[0029] The signal conditioning circuit includes a comparator U1. Pin 1 of the comparator U1 is electrically connected to one end of a resistor R1. Pin 2 of the comparator U1 is electrically connected to one end of a resistor R2, one end of a resistor R4, and one end of a resistor R5. The other end of a resistor R5 is grounded. The other end of a resistor R4 and pin 4 of the comparator U1 are both electrically connected to a 5V voltage. The other end of a resistor R2 is electrically connected to the other end of a resistor R1. The other end of a resistor R2 is also electrically connected to one end of a resistor R3 and one end of a capacitor C1. The other end of a capacitor C1 is grounded. Pin 3 of the comparator U1 is electrically connected to one end of a capacitor C2. The other end of a capacitor C2 is electrically connected to one end of a resistor R6. The other end of a resistor R6 is electrically connected to pin 1 of the comparator U1.

[0030] The signal conditioning circuit operates as follows: the original signal is transmitted to the other end of resistor R2 via resistor R3. Here, resistors R2 and R3, along with the grounded capacitor C1, form an RC-coupled filter circuit, which filters out the DC offset component and low-frequency noise mixed in the original signal, initially optimizing the signal quality and avoiding interference from basic noise to subsequent signal processing. Resistor R4 and the grounded resistor R5 form a voltage divider circuit. Since the other end of resistor R4 is connected to a 5V voltage, the voltage divider provides a stable reference voltage to pin 2 of comparator U1. At the same time, the sensor signal after RC filtering is also transmitted to pin 2 of comparator U1 via resistor R2, so that the sensor signal and the reference voltage are compared at the comparator input, preparing for signal amplification; simultaneously, pin 4 of comparator U1 is connected to... A 5V voltage is input as the operating power supply to ensure the normal operation of the comparator. It amplifies the difference between the sensor signal input at pin 2 and the reference voltage. At the same time, pin 1 of comparator U1 forms a positive feedback loop with pin 3 through resistor R6, capacitor C2, and pin 3. This loop can enhance the signal driving capability of the comparator and avoid signal attenuation after amplification. Finally, pin 1 of comparator U1 outputs a conditioned standard analog signal. The standard analog signal output from pin 1 of comparator U1 is transmitted to the subsequent isolation transmission unit through resistor R1 to prepare for signal isolation transmission. On the other hand, the positive feedback loop continuously optimizes the stability of the output signal, ensuring that the signal finally delivered to the isolation transmission unit is accurate and distortion-free, meeting the signal acquisition requirements of the main control module.

[0031] The multi-sensor system includes a pressure sensor, a temperature sensor, a harmonic sensor, and a fuel composition sensor. The pressure sensor is used to collect boiler pressure parameters, the temperature sensor is used to collect turbine temperature parameters, the harmonic sensor is used to collect grid harmonic content parameters, and the fuel composition sensor is used to collect fuel composition percentage parameters. The signal output terminals of each sensor are electrically connected to the other end of resistor R3 in the signal conditioning circuit.

[0032] The isolated transmission unit adopts an optocoupler isolation transmission method. The input terminal of the optocoupler is electrically connected to pin 3 of comparator U1 in the signal conditioning circuit, the output terminal of the optocoupler is electrically connected to the signal input terminal of the main control module, and the power supply terminal of the optocoupler is electrically connected to the power supply terminal of the anti-interference power supply circuit.

[0033] The anti-interference power supply circuit includes operational amplifier U2. Pin 1 of operational amplifier U2 is electrically connected to one end of capacitor C4. The other end of capacitor C4 is electrically connected to the cathode of diode D2, the anode of diode D1, one end of resistor R8, and one end of resistor R7. The other end of resistor R8, the cathode of diode D1, and the anode of diode D2 are all grounded. Pin 2 of operational amplifier U2 is electrically connected to one end of resistor R12, and the other end of resistor R12 is grounded. Pin 5 of operational amplifier U2 is electrically connected to one end of capacitor C3. The other end of capacitor C3 is connected to the operational amplifier U2. Pin 2 of operational amplifier U2 is electrically connected to the positive terminal of diode D3 and one end of capacitor C5. The negative terminal of diode D3 is electrically connected to one end of resistor R11. The other end of resistor R11 is electrically connected to pin 2 of operational amplifier U2. Pin 4 of operational amplifier U2 is electrically connected to one end of resistor R9. The other end of resistor R9 is electrically connected to the other end of capacitor C5. Pin 3 of operational amplifier U2 is electrically connected to one end of resistor R10. The other end of resistor R10 and pin 4 of operational amplifier U2 are both electrically connected to a 5V voltage.

[0034] When the anti-interference power supply circuit is running, a 5V voltage is first connected to pin 4 of operational amplifier U2 and resistor R10 as the initial power supply. The 5V voltage connected to pin 4 is also transmitted to capacitor C5 via resistor R9, forming a preliminary power supply circuit with pin 3 to ensure the operational amplifier starts up. After operational amplifier U2 starts up, part of the voltage signal output from pin 3 is fed back to pin 2 via diode D3 and resistor R11. This forms an RC filter and feedback regulation circuit with grounded resistor R12 and capacitor C3 between pins 5 and 2, filtering out low-frequency ripple in the voltage and stabilizing the operational amplifier output. The voltage is used for one part of the circuit, and the other part drives the subsequent output of the circuit. The operational amplifier U2 outputs a processed and stable voltage at pin 1. This voltage is first sent to capacitor C4. Capacitor C4, together with resistor R7 and grounded resistor R8, further filters out high-frequency interference. At the same time, diode D1 and diode D2 form a bidirectional clamping circuit to clamp the abnormal overvoltage across capacitor C4 within a safe range. Finally, a stable and interference-free voltage is output through capacitor C4 and resistor R7, which provides reliable power supply for various modules such as signal conditioning circuit, main control module, and alarm circuit, and avoids power ripple and transient surges affecting the operation of each module.

[0035] The alarm circuit includes an alarm K1. Pin 2 of the alarm K1 is electrically connected to pin 1 of transistor Q1 and the negative terminal of diode D4. The positive terminal of diode D4 is electrically connected to one end of resistor R13. The other end of resistor R13 is electrically connected to pin 1 of the alarm K1. Pin 1 of the alarm K1 is electrically connected to the positive terminal of diode D5 and pin 1 of transistor Q2. The negative terminal of diode D5 is electrically connected to the positive terminal of diode D6. Pin 3 of transistor Q2 is electrically connected to one end of resistor R15. The other end of resistor R15 is electrically connected to the negative terminal of diode D6. Pin 3 of transistor Q1 is electrically connected to one end of resistor R14 and pin 2 of transistor Q2. Pin 2 of transistor Q1 is electrically connected to the other end of resistor R14.

[0036] When the alarm circuit is running, an external operating voltage is first applied. When the main control module determines that the parameters are abnormal and outputs a corresponding trigger signal: If it is a serious abnormality, the trigger signal energizes pin 2 of transistor Q1, turning on transistor Q1. Current is transmitted through pin 1 of transistor Q1 to pin 2 of alarm K1. At the same time, pin 1 of alarm K1 forms a circuit through resistor R13 and diode D4, energizing alarm K1 and emitting a high-decibel alarm sound. Diode D4 prevents reverse current flow from damaging transistor Q1. If it is a minor warning, the trigger signal energizes pin 2 of transistor Q2 (pin 2 of transistor Q2...). 2. Connected to pin 3 of transistor Q1 and resistor R14 to form a linkage control logic), transistor Q2 is turned on, and the current is transmitted through pin 1 of transistor Q2 to pin 1 of alarm K1. At the same time, pin 1 of alarm K1 forms a circuit with diode D5, diode D6 and resistor R15. Alarm K1 issues intermittent alarm or low-intensity warning according to the preset mode. Diode D5 and diode D6 play a reverse voltage protection role. Resistors R13, R14 and R15 limit the current of each branch respectively to prevent the components from burning out due to overcurrent, and finally realize accurate alarm response to different levels of abnormality.

[0037] The main control module includes a microcontroller chip, a storage module, and a communication module. The storage module is electrically connected to the storage interface of the microcontroller chip and is used to store the acquisition thresholds and historical data of multiple parameters. The communication module is electrically connected to the communication interface of the microcontroller chip and uses RS485 communication to realize data interaction with the power plant's central monitoring system. The execution module includes a relay drive circuit and a frequency converter drive circuit. The relay drive circuit is used to control the on / off of the power plant's switching equipment, and the frequency converter drive circuit is used to adjust the operating frequency of the power plant's motor equipment. The control terminals of both the relay drive circuit and the frequency converter drive circuit are electrically connected to the control output terminal of the main control module.

[0038] This invention comprehensively collects core operating parameters of power plants using four types of dedicated sensors: pressure, temperature, harmonics, and fuel composition. Combined with the filtering and amplification of the signal conditioning circuit and the isolation transmission design of the optocoupler, it significantly improves the accuracy of parameter measurement and effectively solves the problems of insufficient front-end conditioning and susceptibility to interference in traditional devices. At the same time, the multi-stage filtering and clamping protection of the anti-interference power supply circuit, along with the electromagnetic shielding and dustproof heat dissipation design of the stainless steel protective shell, ensures stable operation of the device under complex conditions of high dust and high electromagnetic interference. In addition, the alarm circuit's graded warning function allows for rapid response to anomalies without manual intervention, reducing operation and maintenance costs and risks.

[0039] It should be noted that the preferred optocoupler model is Avago ACPL-P480-500E. Its working principle is based on the "electric-optical-electric" isolation conversion logic. When the standard analog signal output from the signal conditioning circuit enters the input terminal of the optocoupler, it drives the internal light-emitting diode to emit light. The light intensity changes with the input electrical signal. The input terminal and the output terminal are coupled through an optical medium and have no electrical connection. After the phototransistor at the output terminal receives the light signal, it will convert the light intensity signal in reverse into an electrical signal with the same change law as the input signal. At the same time, the isolation voltage of up to 5000Vrms is used to block the grounding noise and common-mode interference in the strong electromagnetic environment of the power plant from entering the main control module through the signal loop. Finally, the interference-free signal is transmitted to the signal input terminal of the main control module, realizing the dual functions of signal isolation transmission and anti-interference.

[0040] The preferred microcontroller chip is the APM32F402 from Jihai. Its working principle relies on the Arm Cortex-M4F core as the computing and control core. First, it converts the analog signal transmitted by the optocoupler into a digital signal through a built-in 12-bit high-precision ADC. Then, it compares and analyzes the preset parameter safety thresholds stored in the memory module. If the parameters are normal, real-time data is uploaded to the power plant's central monitoring system via the U(S)ART interface (with peripheral circuitry to achieve RS485 communication), and historical data is stored synchronously. If the parameters are abnormal, corresponding control commands are immediately generated and sent to the execution module via GPIO ports or the PWM module to drive relays or frequency converters. Simultaneously, an alarm trigger signal is output to the alarm circuit. During this process, the built-in ESD protection and anti-interference design ensure stable data processing, command generation, and peripheral interaction in the high electromagnetic environment of the power plant, achieving a closed-loop intelligent control of the device. Its specific operating principle is existing technology in this field and will not be elaborated upon separately below.

[0041] Working principle: During use, after the power plant's industrial power is connected, the current enters the circuit containing operational amplifier U2. Operational amplifier U2, together with resistors R7, R8, and R9, and capacitors C4 and C5, forms an active filter circuit to suppress transient surges and high-frequency interference in the power supply. Diodes D1 and D2 form a bidirectional clamping circuit to clamp abnormal overvoltages within a safe range, preventing component damage. Capacitor C3, along with resistors R11 and R12, forms an RC filter network to perform secondary filtering on the output voltage of operational amplifier U2, ultimately outputting a stable voltage. This voltage is then sent to the main control module, signal conditioning circuit, alarm circuit, execution module, and isolation transmission unit, completely avoiding the impact of power supply ripple on the accuracy of parameter acquisition and control signals.

[0042] Pressure sensors are installed at boiler pressure monitoring points to convert the physical boiler pressure signal into an analog electrical signal. Temperature sensors are attached to key temperature measurement points on the turbine, outputting an analog electrical signal corresponding to the turbine temperature through temperature-to-electrical signal conversion. Harmonic sensors are connected in series or parallel to the power plant's power grid lines to detect harmonic current / voltage components and convert them into analog electrical signals indicating harmonic content. Fuel composition sensors are installed in fuel delivery pipelines or silos, obtaining the proportions of carbon, hydrogen, sulfur, and other components in the fuel through composition detection technology and outputting corresponding analog electrical signals. The signal output terminals of all sensors are electrically connected to the other end of resistor R3 in the signal conditioning circuit, transmitting the original analog signal to the signal conditioning circuit. Resistors R2 and R3, along with capacitor C1, form an RC coupling circuit to filter out harmful components from the original signal. DC offset and low-frequency noise; resistors R4 and R5 form a voltage divider circuit to provide a stable reference voltage for comparator U1, ensuring that comparator U1 accurately amplifies weak signals; capacitor C2 and resistor R6 form a positive feedback loop to enhance signal driving capability, and finally output a conditioned standard analog signal. The conditioned signal is sent to the input terminal of the optocoupler of the isolation transmission unit. The electrical signal at the input terminal of the optocoupler triggers the light-emitting diode to emit light, and the phototransistor at the output terminal receives the light signal and converts it into an electrical signal, completely cutting off the electrical connection between the input and output circuits, avoiding grounding noise and common-mode interference from the strong electromagnetic environment of the power plant from entering the main control module. At the same time, the power supply terminal of the optocoupler is powered by an anti-interference power supply circuit to further ensure transmission stability, and finally the signal is sent to the signal input terminal of the main control module.

[0043] The microcontroller chip in the main control module receives signals from the isolated transmission unit, converts them into digital signals, and transmits them to the storage module. The storage module records real-time data, historical change curves, and preset safety thresholds for each parameter. Simultaneously, the real-time data is uploaded to the power plant's central monitoring system via an RS485 communication module for remote viewing by staff. The microcontroller chip compares the real-time parameter digital signals with the safety thresholds in the storage module. If the parameters are within the safe range, the equipment is considered to be operating normally, maintaining the current state and continuously uploading data. If the parameters exceed the safety threshold (e.g., excessive boiler pressure), a corresponding control command is generated and sent to the execution module. At the control end, an alarm signal is triggered simultaneously. After receiving the instruction from the main control module, the execution module controls the start and stop of power plant switching equipment (such as fuel supply valves) through its own relays according to the on / off instructions (such as cutting off fuel supply when the pressure is too high). At the same time, after receiving the alarm signal from the main control module, the alarm circuit realizes graded warning through the conduction logic of transistors Q1 and Q2: when the parameter is seriously abnormal, transistor Q1 conducts, and alarm K1 is powered on to emit a high-decibel alarm sound; when the parameter is close to the safety threshold (slight warning), transistor Q2 conducts, and together with diodes D5 and D6 and resistor R15, a circuit is formed, and alarm K1 can emit intermittent alarms according to the preset mode.

[0044] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A multi-parameter monitoring and automatic control device for power plants, characterized in that, It includes multiple sensors, signal conditioning circuit, main control module, alarm circuit, execution module, anti-interference power supply circuit and isolation transmission unit; The signal conditioning circuit is electrically connected to the main control module through an isolation transmission unit, the signal conditioning circuit is electrically connected to multiple sensors, the execution module is electrically connected to the main control module and the anti-interference power supply circuit, and the main control module is electrically connected to the alarm circuit.

2. The automatic control device for multi-parameter monitoring in a power plant according to claim 1, characterized in that, The signal conditioning circuit includes a comparator U1. Pin 1 of the comparator U1 is electrically connected to one end of a resistor R1. Pin 2 of the comparator U1 is electrically connected to one end of a resistor R2, one end of a resistor R4, and one end of a resistor R5. The other end of resistor R5 is grounded. The other end of resistor R4 and pin 4 of the comparator U1 are both electrically connected to a 5V voltage. The other end of resistor R2 is electrically connected to the other end of resistor R1. The other end of resistor R2 is also electrically connected to one end of resistor R3 and one end of capacitor C1. The other end of capacitor C1 is grounded. Pin 3 of the comparator U1 is electrically connected to one end of capacitor C2. The other end of capacitor C2 is electrically connected to one end of resistor R6. The other end of resistor R6 is electrically connected to pin 1 of the comparator U1.

3. The automatic control device for multi-parameter monitoring in a power plant according to claim 1, characterized in that, The anti-interference power supply circuit includes an operational amplifier U2. Pin 1 of the operational amplifier U2 is electrically connected to one end of a capacitor C4. The other end of capacitor C4 is electrically connected to the cathode of diode D2, the anode of diode D1, one end of resistor R8, and one end of resistor R7. The other end of resistor R8, the cathode of diode D1, and the anode of diode D2 are all grounded. Pin 2 of the operational amplifier U2 is electrically connected to one end of resistor R12, and the other end of resistor R12 is grounded. Pin 5 of the operational amplifier U2 is electrically connected to one end of capacitor C3. The other end of capacitor C3 is connected to the operational amplifier... Pin 2 of U2 is electrically connected to the positive terminal of diode D3 and one end of capacitor C5. The negative terminal of diode D3 is electrically connected to one end of resistor R11. The other end of resistor R11 is electrically connected to pin 2 of operational amplifier U2. Pin 4 of operational amplifier U2 is electrically connected to one end of resistor R9. The other end of resistor R9 is electrically connected to the other end of capacitor C5. Pin 3 of operational amplifier U2 is electrically connected to one end of resistor R10. The other end of resistor R10 and pin 4 of operational amplifier U2 are both electrically connected to a 5V voltage.

4. The power plant multi-parameter monitoring and automatic control device according to claim 1, characterized in that, The alarm circuit includes an alarm K1. Pin 2 of the alarm K1 is electrically connected to pin 1 of transistor Q1 and the negative terminal of diode D4. The positive terminal of diode D4 is electrically connected to one end of resistor R13. The other end of resistor R13 is electrically connected to pin 1 of the alarm K1. Pin 1 of the alarm K1 is electrically connected to the positive terminal of diode D5 and pin 1 of transistor Q2. The negative terminal of diode D5 is electrically connected to the positive terminal of diode D6. Pin 3 of transistor Q2 is electrically connected to one end of resistor R15. The other end of resistor R15 is electrically connected to the negative terminal of diode D6. Pin 3 of transistor Q1 is electrically connected to one end of resistor R14 and pin 2 of transistor Q2. Pin 2 of transistor Q1 is electrically connected to the other end of resistor R14.

5. The automatic control device for multi-parameter monitoring of a power plant according to claim 2, characterized in that, The multi-sensor system includes a pressure sensor, a temperature sensor, a harmonic sensor, and a fuel composition sensor. The pressure sensor is used to collect boiler pressure parameters, the temperature sensor is used to collect turbine temperature parameters, the harmonic sensor is used to collect grid harmonic content parameters, and the fuel composition sensor is used to collect fuel composition percentage parameters. The signal output terminals of each sensor are electrically connected to the other end of resistor R3 in the signal conditioning circuit.

6. The automatic control device for multi-parameter monitoring in a power plant according to claim 2, characterized in that, The isolated transmission unit adopts an optocoupler isolation transmission method. The input end of the optocoupler is electrically connected to pin 3 of comparator U1 in the signal conditioning circuit, the output end of the optocoupler is electrically connected to the signal input end of the main control module, and the power supply end of the optocoupler is electrically connected to the power supply end of the anti-interference power supply circuit.

7. The automatic control device for multi-parameter monitoring in a power plant according to claim 1, characterized in that, The main control module includes a microcontroller chip, a storage module, and a communication module. The storage module is electrically connected to the storage interface of the microcontroller chip and is used to store the acquisition thresholds and historical data of multiple parameters. The communication module is electrically connected to the communication interface of the microcontroller chip and adopts RS485 communication to realize data interaction with the power plant's central monitoring system. The execution module includes a relay drive circuit and a frequency converter drive circuit. The relay drive circuit is used to control the on / off of the power plant's switching equipment, and the frequency converter drive circuit is used to adjust the operating frequency of the power plant's motor equipment. The control terminals of both the relay drive circuit and the frequency converter drive circuit are electrically connected to the control output terminal of the main control module.

8. The automatic control device for multi-parameter monitoring in a power plant according to claim 1, characterized in that, The automatic control device also includes a protective housing made of stainless steel. The inner wall of the protective housing is provided with an electromagnetic shielding layer. Multiple sensors, signal conditioning circuits, main control modules, alarm circuits, execution modules, anti-interference power supply circuits, and isolation transmission units are all installed inside the protective housing. The surface of the protective housing has heat dissipation holes, and dustproof nets are installed at the heat dissipation holes.

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