Regional power grid load detection circuit and detection method thereof

Abstract

The invention discloses a regional power grid load detection circuit and a detection method thereof, and relates to the technical field of smart power grids. The signal acquisition module is used for acquiring a voltage signal and a current signal of a power grid line through a voltage acquisition circuit and a current acquisition circuit; the zero-cross detection module is used for acquiring a synchronous pulse signal when the power supply crosses a zero point; the MCU master control module is used for regulating and controlling the operation of the driving load module according to the synchronous pulse signal, the voltage signal and the current signal, and displaying data according to the input data and the operation regulation and control of the driving load module; and the driving load module is used for regulating and controlling the operation of a power grid load according to the operation instruction of the MCU main control module. Real-time acquisition of voltage and current signals of a power grid line is realized, accurate synchronization with a zero crossing point of a power supply can be realized, a load operation state can be judged according to phase difference analysis of the voltage / current signals, and a protection mechanism can be triggered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smart grid, in particular to a regional power grid load detection circuit and a detection method thereof. BACKGROUND

[0002] As a key link connecting the backbone power grid and end users, the stability, safety and economy of regional power grid are of great importance. Accurate and real-time grasp of the load state of regional power grid is the basis for fine management of power grid, guarantee of power supply reliability, optimization of dispatching strategy, prevention of overload accidents, improvement of power quality and scientific planning.

[0003] The Chinese utility model patent with publication number CN221174793U discloses a high-voltage direct-current solid-state switch with metering function, which comprises: a power supply module for voltage conversion to provide power for internal modules; an electric energy metering module for collecting current electric energy information and sending it to a processor control module, the electric energy information including voltage, current, power, current electric energy and cumulative electric energy; a communication module for transmitting the electric energy information reported by the processor to an upper computer system; a processor control module for sending the electric energy information received from the electric energy metering module to the upper computer system through the communication module; and a power circuit module for accepting instructions from the processor control module to realize line opening and closing. The high-voltage direct-current solid-state switch in the technical solution realizes electric energy information metering and storage, providing users with a more intelligent use experience and facilitating users to reasonably arrange electric energy equipment and electric energy period.

[0004] The above technical solution can monitor the load state of regional power grid through measurement of voltage and current, but it cannot accurately synchronize with the power zero-crossing point, limiting the ability to accurately judge the load operating state and timely trigger the protection mechanism. SUMMARY

[0005] The present application aims to provide a regional power grid load detection circuit and a detection method thereof to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a regional power grid load detection circuit, comprising: A signal acquisition module: through the set voltage acquisition circuit and current acquisition circuit, the voltage signal and current signal of the power grid line are obtained; A zero-crossing detection module: a synchronization pulse signal at the power zero-crossing point is obtained; An MCU master module electrically connected with the signal acquisition module and the zero-crossing detection module: according to the synchronization pulse signal, the voltage signal and the current signal, the operation of the driving load module is regulated, and according to the input data and the operation regulation of the driving load module, data display is performed; A driving load module electrically connected with the MCU master module: according to the operation instruction of the MCU master module, the operation of the power grid load is regulated.

[0007] Further, the MCU master module comprises an MCU master controller, a display circuit and a key circuit, the display circuit is electrically connected with the key circuit through the MCU master controller, and the signal acquisition module, the zero-crossing detection module and the driving load module are all electrically connected with the MCU master controller.

[0008] Further, the MCU master controller is electrically connected with the voltage acquisition circuit through a UAD port, is electrically connected with the current acquisition circuit through an AD port, is electrically connected with the zero-crossing detection module through a ZERO port, and is electrically connected with the driving load module through a REL2 port. — Further, the MCU master controller is electrically connected with the voltage acquisition circuit through a UAD port, is electrically connected with the current acquisition circuit through an AD port, is electrically connected with the zero-crossing detection module through a ZERO port, and is electrically connected with the driving load module through a REL2 port.

[0009] Further, the zero-crossing detection module is electrically connected with a power conversion module, the power conversion module is electrically connected with the current acquisition circuit through a CUR — AD port, and the power conversion module is used for providing a 5V direct current power supply.

[0010] A detection method of a regional power grid load detection circuit, the detection method comprises the following steps: S1: signal acquisition: after the regional power grid load detection circuit is powered on and initialized, a voltage signal, a current signal and a synchronization pulse signal are acquired; S2: intelligent regulation: according to the voltage signal, the current signal and the synchronization pulse signal, a load access state and an operation state are determined; S3: monitoring and protection: a signal threshold is set through a key circuit, the current signal and the voltage signal are monitored according to the signal threshold, and early warning protection is performed according to the monitoring result.

[0011] Further, the voltage signal, the current signal and the synchronization pulse signal are acquired, which comprises the following steps: S1.1: voltage signal acquisition: a high-voltage signal is stepped down through a voltage division network composed of resistors R4, R6 and R7, and is transmitted to an MCU master controller after being filtered through a capacitor C2; S1.2: Current signal acquisition: The acquisition signal of resistor R30 is amplified by operational amplifier U3A, and the amplified signal is transmitted to the MCU main controller; S1.3: Synchronization pulse signal acquisition: The sine wave signal is converted into a square wave signal by transistor Q1, and the square wave signal is transmitted to the MCU main controller through the ZERO port.

[0012] Further, the load access state and the running state are determined, including: S2.1: Load state determination: When the FEED signal changes and the diode D4 is turned on, the load is accessed, and at the next zero crossing point, the transistor Q3 is driven through the REL1 port, the transistor Q2 is enabled through the REL2 port, and the state of the accessed load is determined according to the phase difference between the voltage signal and the current signal; S2.2: Control protection: When the accessed load is abnormal, the output of the REL1 port or the REL2 port is closed within the best breaking time, and the diode D6 discharges the reverse electromotive force of the relay REL1.

[0013] Further, the phase difference between the voltage signal and the current signal is compared with the preset phase threshold, and the state of the accessed load is determined according to the comparison result, specifically: When the phase difference is less than the preset phase threshold, the accessed load is in normal operation; otherwise, the accessed load is abnormal, and the control protection is performed through the driving load module.

[0014] Further, the early warning protection is performed, including: S3.1: Threshold setting: The signal threshold is adjusted according to the pressing time of the key in the key circuit and the step coefficient, specifically:

[0015] Wherein: is a new signal threshold after adjustment, is a current signal threshold, is a step coefficient, is a key continuous pressing time, is a time reference unit; S3.2: Early warning protection: The signal threshold is compared with the current signal and the voltage signal, when the current signal is greater than the signal threshold, the overcurrent protection is performed, and when the voltage signal is greater than the signal threshold, the early warning signal is triggered.

[0016] Compared with the prior art, the beneficial effects of the present application are: One: the application realizes real-time collection of power grid line voltage and current signals through the cooperative work of the signal collection module and the zero-crossing detection module, and can be accurately synchronized with the power zero-crossing point, and the load running state can be judged according to the phase difference analysis of the voltage / current signal, and the protection mechanism is triggered; Secondly, the application can effectively reduce high-voltage signal interference through three-stage voltage division network and capacitor filtering for voltage collection, improve the sensitivity of current detection through the operation amplifier for current signal collection, and ensure the phase synchronization accuracy through the conversion of the sine wave into a square wave signal by the triode. Thirdly, the application can adapt to different scene requirements by flexibly setting the overcurrent / overvoltage threshold through the key circuit, and can avoid device damage through the cooperative control of the triodes Q2 and Q3 of the driving load module and the use of the diode D6 to discharge the reverse electromotive force. Fourthly, the application displays real-time data through the nixie tube and is equipped with a self-checking function, so as to facilitate fault troubleshooting, and the modules are electrically connected through standardized ports, so that the faulty unit can be directly replaced during maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The system block diagram of the regional power grid load detection circuit in the application is shown in the figure; Figure 2 The circuit diagram of the power conversion module in the application is shown in the figure; Figure 3 The circuit diagram of the current collection circuit in the application is shown in the figure; Figure 4 The circuit diagram of the zero-crossing detection module in the application is shown in the figure; Figure 5 The circuit diagram of the MCU main controller in the application is shown in the figure; Figure 6 The circuit diagram of the display circuit in the application is shown in the figure; Figure 7 The circuit diagram of the key circuit in the application is shown in the figure; Figure 8 The circuit diagram of the voltage collection circuit in the application is shown in the figure; Figure 9 The circuit diagram of the driving load module in the application is shown in the figure. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0019] Embodiment 1

[0020] With reference to Figures 1-9 The embodiment provides a regional power grid load detection circuit, which comprises a power conversion module, an MCU main control module, a driving load module, a signal acquisition module and a zero-crossing detection module. The MCU main control module comprises an MCU main controller, a display circuit and a key circuit, and the signal acquisition module comprises a voltage acquisition circuit and a current acquisition circuit. Specifically, the MCU main controller is electrically connected with the display circuit, the key circuit, the voltage acquisition circuit, the current acquisition circuit, the zero-crossing detection module and the driving load module, the power conversion module is electrically connected with the current acquisition circuit and the zero-crossing detection module, and the driving load module is electrically connected with the voltage acquisition circuit.

[0021] In the embodiment, the power conversion module is used for converting alternating current into 5V direct current to provide 5V direct current power supply for the whole regional power grid load detection circuit. Figure 2 The power conversion module comprises an alternating current input port ACN1, ACL1 and ACL2, wherein the alternating current input port ACN1 is electrically connected with a capacitor EC3, a capacitor C4, a resistor R11 and a current acquisition circuit through a fuse F2 and a resistor R13, the alternating current input ports ACL1 and ACL2 are both electrically connected with a resistor VDR1, a resistor R5, a resistor R9 and a capacitor CX1 through a fuse F1, the resistor R9 is electrically connected with a resistor R12, and the resistor VDR1, the resistor R12 and the capacitor CX1 are all electrically connected with the fuse F2 and the resistor R13. It is worth noting that the series circuit composed of the resistor VDR1, the capacitor CX1 and the resistors R9 and R12 are parallel with each other.

[0022] Further, the resistor R5 is electrically connected with the zero-crossing detection module and a diode D2, the diode D2 is electrically connected with an inductor L1, a resistor R8 and a capacitor EC1 through a diode D3, the inductor L1 and the resistor R8 are parallel with each other and are electrically connected with a capacitor EC2 and a 4th port of a chip U1, the capacitor EC2 is electrically connected with a 5th port and a 6th port of the chip U1 through an inductor L2, the 6th port of the chip U1 is electrically connected with an 8th port of the chip U1 through a capacitor C3, a 2nd port of the chip U1 is electrically connected with the capacitor EC3, the capacitor C4 and the resistor R11, and the capacitors EC1, EC2, EC3, C4, the resistor R11 and the inductor L2 are all electrically connected with a 1st port of the chip U1.

[0023] Specifically, the alternating current enters the internal of the power conversion module through the overcurrent protection of the fuse F1, is absorbed by the resistance VDR1 after the surge voltage, and is filtered by the capacitor CX1. Then, the alternating current is processed by full-wave rectification through the diode D2 and the diode D3, is filtered by the inductor L1 and the capacitor EC2 to form a π-type filter, and outputs a high-voltage direct current of 300 V. Then, the high-voltage direct current of 300 V is processed by the chip U1 to output a direct current of 5 V, and the current acquisition circuit monitors the current in real time through the resistance R13 and cooperates with the chip U1 to perform overcurrent protection. Further, the output direct current of 5 V is filtered by the inductor L2 and the capacitor C4, and then the stable direct current of 5 V is output through the capacitor EC3 and the resistance R11.

[0024] In the embodiment, the current acquisition circuit is used to acquire the current signal of the power grid line. Referring to Figure 3 , the current acquisition circuit comprises an operational amplifier U3A, the inverting input end of the operational amplifier U3A is electrically connected with the resistances R30 and R32 and the capacitor C10, and the non-inverting input end of the operational amplifier U3A is electrically connected with the resistance R28 and the capacitor C8. The resistance R30 is electrically connected with the alternating current input port ACN1 of the power conversion module, the resistance R32 is connected in parallel with the capacitor C11, and the parallel circuit formed by the resistance R32 and the capacitor C11 is electrically connected with the resistance R29 and the output end of the operational amplifier U3A, the capacitor C10 is electrically connected with the capacitor C9, and the capacitors C9 and C10 are grounded. The resistance R28 is electrically connected with the resistance R29, the capacitor C9 and the I — AD port of the MCU main controller through the diode D7, and the capacitor C8 is electrically connected with the ground end of the operational amplifier U3A. The power supply end of the operational amplifier U3A is electrically connected with the diode D7 and the capacitor C12, and the capacitor C12 is grounded.

[0025] Specifically, the CUR — AD signal of the current acquisition circuit is amplified by the operational amplifier U3A, and the amplification multiple is determined according to the resistance values of the resistances R29 and R30, so that the amplified I — AD signal is obtained, and the I — AD signal is sent to the MCU main controller for measurement.

[0026] In the embodiment, the zero-crossing detection module is used to acquire the synchronization pulse signal at the zero-crossing point of the power supply. Referring to Figure 4 , the zero-crossing detection module comprises a triode Q1, the base of the triode Q1 is electrically connected with the resistance R5 and the diode D2 of the power conversion module through the resistances R2 and R3, the collector of the triode Q1 is electrically connected with the resistance R1, the capacitor C1 and the ZERO port of the MCU main controller, the emitter of the triode Q1 is electrically connected with the resistance R3 through the diode D5, and the emitter of the triode Q1, the anode of the diode D5 and the capacitor C1 are grounded.

[0027] Specifically, 5V DC current is transmitted to the MCU main controller through the ZERO port after current limiting by the resistor R1. Meanwhile, when the transistor Q1 is turned on, the voltage at the ZERO port will be pulled down to near ground level, and when the transistor Q1 is turned off, the voltage at the ZERO port can be pulled up to the high level +5V through the resistor R1.

[0028] In the embodiment, the MCU main control module includes a MCU main controller, a display circuit and a key circuit. Referring to Figure 5 , the UAD port of the MCU main controller is electrically connected with the voltage acquisition circuit, and the REL1 and REL2 ports are electrically connected with the driving load module, SEGE, SEGH and Key — Com1 port is electrically connected with the key circuit, SEGA, SEGB, SEGC, SEGD, SEGE, SEGF, SGG and SEGH ports, and the SEGA, SEGB, SEGC, SEGD, SEGE, SEGF, SGG and SEGH ports are electrically connected with the display circuit.

[0029] Further, referring to Figure 6 , the display circuit includes a number tube, wherein the 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 ports of the number tube are electrically connected with the SEGA, SEGB, SEGC, SEGD, SEGE, SEGF, SGG and SEGH ports of the MCU main controller through the resistors R14, R15, R16, R17, R18, R20, R22 and R23 respectively. Referring to Figure 7 , the key circuit includes the keys K201 and K202, wherein the key K201 is electrically connected with the SEGE port of the MCU main controller through the resistor R26, the key K202 is electrically connected with the SEGH port of the MCU main controller through the resistor R27, and the keys K201 and K202 are both grounded through the capacitor C7, and the keys K201 and K202 are both electrically connected with the Key — Com1 port of the MCU main controller.

[0030] Specifically, when the keys K201 and K202 are pressed, the SEGE, SEGH and Key — Com1 ports of the MCU main controller will be turned on, at this time, the MCU main controller detects the input triggered by the low level, wherein the resistors R26 and R27 are current limiting resistors to prevent GPIO overcurrent, and the capacitor C7 is used to filter the key jitter noise. Meanwhile, the number tube in the embodiment is a double connection design and contains COM1 and COM2 common ports. That is to say, the MCU main controller can control the turn-on of the COM1 and COM2 common ports by time sharing, and realize dynamic scanning display of the number tube by combining the signals of the SEGA, SEGB, SEGC, SEGD, SEGE, SEGF, SGG and SEGH ports.

[0031] Further, referring to Figure 8 , the voltage acquisition circuit includes diodes D1 and D4, wherein the UAD port of the MCU main controller is electrically connected with the diode D1, resistors R4 and R10, and capacitor C2, wherein the resistor R10 and the capacitor C2 are connected in parallel with each other and grounded, and the resistor R4 is electrically connected with the driving load module through resistors R7, R6 and diode D4 in sequence. Specifically, the FEED signal of the driving load module can be transmitted in one direction through the diode D4, and after the input FEED signal is reduced through series voltage division of the resistors R4, R6 and R7, the FEED signal can be transmitted to the MCU main controller through the UAD port.

[0032] Further, referring to Figure 9 , the driving load module includes a relay REL1, wherein the 1 port of the relay REL1 is electrically connected with the +5V power port, the 3 port is electrically connected with the diode D4 of the voltage acquisition circuit, the 5 port is electrically connected with the collector of the triode Q2, and the 4 port of the relay REL1 is electrically connected with the 5 port of the relay REL1 through the diode D6. Meanwhile, the base of the triode Q2 is electrically connected with the resistor R19 through the resistor R21, the emitter of the triode Q2 and the collector of the triode Q3, and the resistor R19 is electrically connected with the REL1 port of the MCU main controller. The base of the triode Q3 is electrically connected with the emitter of the triode Q3 and the resistor R24 through the resistor R25, the emitter of the triode Q3 and the resistor R25 are grounded, and the resistor R24 is electrically connected with the REL2 port of the MCU main controller.

[0033] Specifically, when the triodes Q2 and Q3 are turned on, the +5V power supply is grounded through the relay REL1, the triode Q2 and the triode Q3, at this time the relay REL1 attracts the contact point, that is, the relay contact point controls the power supply on-off of the motor. And because the diode D6 is connected in parallel across the relay REL1, the reverse electromotive force when the coil of the relay REL1 is powered off can be discharged, thereby preventing the triodes Q2 and Q3 from being broken down.

[0034] Embodiment 2

[0035] The embodiment provides a detection method of a regional power grid load detection circuit, and the detection method comprises the following steps: Step S1: signal acquisition. That is, after the power conversion module is powered on, the relay REL1 in the driving load module is kept in an open state. Specifically, at the moment when the power conversion module is powered on, the REL1 port of the MCU main controller outputs 0V low level, at which time the voltage between the base-emitter of the transistor Q2 in the driving load module is 0V, thereby ensuring that the current at the base of the transistor Q2 is zero, and thus the coil voltage of the relay REL1 is 0V. At the same time, after the MCU main controller initializes the voltage acquisition circuit, the current acquisition circuit and the zero-crossing detection module, the display circuit performs self-checking through the digital display of the nixie tube. Specifically, during self-checking, the SEGA, SEGB, SEGC, SEGD, SEGE, SEGF, SEGG and SEGH ports of the MCU main controller output low level at the same time, and the COM1 and COM2 common ports of the nixie tube are alternately turned on, i.e. self-checking is judged according to the brightness display of each segment of the nixie tube. That is, if each segment of the nixie tube can normally operate, i.e. emit light, the self-checking is completed. At the same time, through the voltage acquisition circuit, the current acquisition circuit and the zero-crossing detection module, the voltage signal, the current signal and the synchronization pulse signal are respectively acquired. The specific process is as follows: Step S1.1: voltage signal acquisition. That is, the high voltage signal is reduced to the range of 0-5V through the voltage division network composed of resistors R4, R6 and R7 in the voltage acquisition circuit, and is transmitted to the MCU main controller after being filtered by capacitor C2, so as to acquire the high voltage signal. In this embodiment, the resistance values of resistors R4, R6 and R7 are all 330kΩ, and the corresponding voltage division ratio is: (330+330) / (330+330+330)=2 / 3. Specifically, after the high voltage signal is unidirectionally conducted through diode D4, it is attenuated by 2 / 3 through the voltage division network composed of resistors R4, R6 and R7, and is low-pass filtered through the low-pass filter composed of capacitor C2 and resistor R10, so as to be transmitted to the MCU main controller for high voltage signal acquisition.

[0036] Specifically, according to the acquired high voltage signal, it is compared with the preset voltage threshold range (set according to the IEC 61000-4-30 Class A standard and the contact voltage of the relay REL1, which is set to 85-0V-300V in this embodiment) and the preset waveform distortion threshold (set according to the IEC 61000-3-2 standard, which is set to 8% in this embodiment), and according to the comparison result, the corresponding signal abnormal type is determined, which is specifically: When the high-voltage signal is less than the lower threshold value 85V of the preset voltage threshold range, the corresponding abnormal type is voltage drop. When the high-voltage signal is greater than the upper threshold value 300V of the preset voltage threshold range, the corresponding abnormal type is voltage overshoot. When the waveform distortion of the high-voltage signal is greater than the preset waveform distortion threshold value 8%, the corresponding abnormal type is waveform distortion. Otherwise, the collected high-voltage signal is normal.

[0037] Step S1.2: Current signal acquisition. That is, the CUR — AD signal is sampled through the resistance R30 in the current acquisition circuit, and the I — AD signal is amplified through the operational amplifier U3A, and the amplified I

[0038] In this embodiment, the instantaneous overcurrent protection threshold value is set according to the resistance value of the resistance R30 and the maximum voltage size collected, the continuous overload protection threshold value is set according to the contact temperature rise size of the relay REL1, and the load loss detection threshold value is set according to the noise voltage of the operational amplifier U3A and the resistance value of the resistance R30. Since the specific formulas of each threshold value are existing conventional formulas, they are not specifically described in this embodiment. Further, the collected current signal is compared with the set instantaneous overcurrent protection threshold value, continuous overload protection threshold value and load loss detection threshold value, and the corresponding signal abnormal type is determined according to the comparison result, which is specifically: When the collected current signal is greater than the instantaneous overcurrent protection threshold value, the corresponding signal abnormal type is instantaneous overcurrent. When the collected current signal is greater than the continuous overload protection threshold value within 3 seconds, the corresponding signal abnormal type is continuous overload. When the collected current signal is less than the load loss detection threshold value within 10 minutes, the corresponding signal abnormal type is load loss. Otherwise, the collected current signal is normal.

[0039] Step S1.3: Synchronous pulse signal acquisition. That is, after the sine wave signal is converted into a square wave signal by the triode Q1 in the zero-crossing detection module, it is transmitted to the MCU main controller through the ZERO port to trigger the MCU main controller to interrupt. Specifically, when the sine wave signal crosses zero and is in the positive half cycle, the triode Q1 is turned on, and the voltage at the ZERO port is 0V. When the sine wave signal crosses zero and is in the negative half cycle, the triode Q1 is cut off, and the voltage at the ZERO port is 5V.

[0040] Step S2: Intelligent regulation. That is, according to the collected voltage signal, current signal and synchronous pulse signal, the connected load is judged, and according to the judgment result, the running state of the load is determined, and according to the running state of the load, the corresponding execution action is determined.

[0041] Step S2.1: Load state determination. That is, according to the collected voltage signal, current signal and synchronization pulse signal, the connected load is judged, and according to the judgment result, the running state of the triode Q2 and Q3 in the driving load module is controlled. Specifically, when no load is connected, the current signal collected by the current collection circuit will be less than 5mA, at this time the output voltage of the operational amplifier U3A is 5V. When the load is connected, the FEED signal collected by the voltage collection circuit will change suddenly, and the diode D4 is turned on. That is, when the FEED signal changes suddenly and the diode D4 is turned on, the load is connected.

[0042] Further, when the load is connected, at the next zero-crossing point, the MCU main controller drives the triode Q3 through the REL1 port and enables the triode Q2 through the REL2 port for conduction control. In this embodiment, according to the phase size of the voltage signal and the phase size of the current signal, the phase difference between the voltage signal and the current signal is obtained, and the obtained phase difference is compared with the preset phase threshold (5° in this embodiment), and according to the comparison result, the state of the connected load is determined, specifically: When the obtained phase difference is less than the preset phase threshold 5°, the connected load is normal. Otherwise, when the obtained phase difference is not less than the preset phase threshold 5°, the connected load is abnormal, at this time the driving load module is controlled for protection.

[0043] Step S2.2: Control and protection. That is, when the connected load is abnormal, the best breaking time is determined by the breaking phase scanning test method. That is, within the best breaking time before or after the zero-crossing point, the MCU main controller closes the output of the REL1 port or the REL2 port. At the same time, the diode D6 is discharged to make the reverse electromotive force of the relay REL1 discharged through the diode D6.

[0044] Step S3: Monitoring protection. That is, the protection threshold of the signal is set through the keys K201 and K202 in the key circuit, and the current signal and the voltage signal are monitored according to the dynamic display of the nixie tube in the display circuit, and when the signal is abnormal, the warning signal is triggered and the overcurrent protection is performed. Specifically as follows: Step S3.1: Threshold setting. That is, according to the pressing time of the keys K201 and K202 and the corresponding step coefficient, the preset signal threshold is adjusted to obtain the adjusted signal threshold, specifically:

[0045] Wherein: is the adjusted new signal threshold, is the current signal threshold, for step coefficient, for key press time, for time reference unit.

[0046] Step S3.2: Early warning protection. That is, according to the current threshold and voltage threshold set in step S3.1, the collected current signal and voltage signal are identified, that is, when the collected current signal is greater than the current threshold, overcurrent protection is performed. When the collected voltage signal is greater than the voltage threshold, an early warning signal is triggered.

[0047] Although embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An area grid load detection circuit, characterized by, The utility model relates to a kind of regional power grid load detection circuit, including: Signal acquisition module: through the voltage acquisition circuit and current acquisition circuit of setting, the voltage signal and current signal of power grid line are obtained; Zero-crossing detection module: the synchronous pulse signal when power supply zero-crossing point is obtained; The MCU main control module electrically connected with the signal acquisition module and zero-crossing detection module: according to the synchronous pulse signal, voltage signal and current signal, the operation of driving load module is regulated, and according to input data and the operation regulation of driving load module, data display is carried out; The driving load module electrically connected with the MCU main control module: according to the operation instruction of the MCU main control module, the operation of power grid load is regulated.

2. The regional grid load detection circuit of claim 1, wherein, The MCU main control module includes MCU main controller, display circuit and key circuit, the display circuit is electrically connected key circuit by MCU main controller, and the signal acquisition module, zero-crossing detection module and driving load module are all electrically connected MCU main controller.

3. A regional grid load detection circuit according to claim 2, wherein, The MCU main controller is electrically connected with the voltage collection circuit through a UAD port, is electrically connected with the current collection circuit through an AD port, is electrically connected with the zero-crossing detection module through a ZERO port, and is electrically connected with the driving load module through a REL2 port. — The MCU main controller is electrically connected with the voltage collection circuit through a UAD port, is electrically connected with the current collection circuit through an AD port, is electrically connected with the zero-crossing detection module through a ZERO port, and is electrically connected with the driving load module through a REL2 port.

4. The regional power grid load detection circuit according to claim 1 or 2 or 3, characterized in that, The zero-crossing detection module is electrically connected with a power conversion module. — The AD port is electrically connected with a current collection circuit, and the power conversion module is used for providing 5V direct current power.

5. A detection method of a regional power grid load detection circuit, characterized by, The power grid load is detected by the regional power grid load detection circuit of any one of claims 1-4, and the detection method includes: S1: signal acquisition: after regional power grid load detection circuit power initialization, voltage signal, current signal and synchronous pulse signal are acquired; S2: intelligent regulation and control: according to the voltage signal, current signal and synchronous pulse signal, the load access state and operating state are determined; S3: monitoring and protection: the signal threshold is set through the key circuit, and the current signal and voltage signal are monitored according to the signal threshold, and the warning protection is carried out according to the monitoring result.

6. The method of claim 5, wherein the method further comprises: Voltage signal, current signal and synchronous pulse signal are acquired, including: S1.1: voltage signal acquisition: the high-voltage signal is stepped down through the voltage division network composed of resistors R4, R6 and R7, and is transmitted to MCU main controller after filtering through capacitor C2; S1.2: current signal acquisition: the acquisition signal of resistor R30 is amplified through operational amplifier U3A, and the amplified signal is transmitted to MCU main controller; S1.3: synchronous pulse signal acquisition: the sine wave signal is converted into square wave signal through triode Q1, and the square wave signal is transmitted to MCU main controller through ZERO port.

7. The method of claim 5, wherein the method further comprises: The load access state and operating state are determined, including: S2.1: load state determination: when FEED signal mutates and diode D4 is turned on, load is accessed, and at the next zero-crossing point, triode Q3 is driven through REL1 port, triode Q2 is enabled through REL2 port after the load is accessed, and the state of the accessed load is determined according to the phase difference between voltage signal and current signal; S2.2: regulation and protection: when the accessed load is abnormal, the output of REL1 port or REL2 port is closed within the best breaking time, and diode D6 discharges the reverse electromotive force of relay REL1.

8. The method of claim 7, wherein, The phase difference between voltage signal and current signal is compared with preset phase threshold, and the state of the accessed load is determined according to the comparison result, specifically: When the phase difference is less than a preset phase threshold, the access load is in normal operation; otherwise, the access load is abnormal, and the driving load module is used for regulation and protection.

9. The method of claim 5, wherein, The early warning protection includes: S3.1: Threshold setting: adjusting the signal threshold according to the pressing time of the key in the key circuit and a step coefficient, specifically: ； wherein: is an adjusted new signal threshold value, is a current set signal threshold value, is a step coefficient, is a key hold time, is a time reference unit; S3.2: Early warning protection: comparing the signal threshold with the current signal and the voltage signal, when the current signal is greater than the signal threshold, overcurrent protection is performed, and when the voltage signal is greater than the signal threshold, an early warning signal is triggered.

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