Electric energy quality monitoring device based on DSP

Abstract

The invention discloses an electric energy quality monitoring device based on a DSP. The electric energy quality monitoring device comprises a data acquisition unit, a signal conditioning unit, a multi-channel data processing unit, a DSP control unit, a power supply loop control unit and a communication unit, the design of the signal conditioning unit fully considers the problems of complexity and noise interference of power grid signals, and through the comprehensive application of the double operational amplifier noise reduction circuit, the reference bias circuit and the low-pass filter circuit, the device can effectively reduce noise and improve the signal-to-noise ratio and purity of the signals. The multi-channel data processing unit is introduced, so that the device can efficiently process a large amount of power grid data, and the data processing speed and efficiency are greatly improved; the DSP control unit, as a core component of the device, not only has a strong data processing capability, but also has excellent coordination and control capabilities, and realizes real-time monitoring and fault early warning of electric energy quality.

Description

Technical Field

[0001] The invention relates to the technical field of power quality monitoring, and in particular to a power quality monitoring device based on DSP. Background Art

[0002] In the field of power systems, power quality is an important indicator to measure the stability and reliability of power supply. It covers multiple aspects such as voltage quality, current quality, power supply quality and power consumption quality, and is directly related to the safe operation of the power grid and the normal operation of various power equipment. However, with the continuous development and complexity of the power system, power quality issues have become increasingly prominent and have become one of the key factors restricting the improvement of power system efficiency.

[0003] However, in the process of power quality monitoring, on the one hand, the voltage and current signals in the power grid often contain a lot of noise and interference, and effective signal conditioning and filtering are required to improve the signal-to-noise ratio and processing accuracy. On the other hand, due to the complexity and dynamics of the power grid, it is necessary to design efficient data processing algorithms and parallel processing mechanisms to achieve real-time processing and analysis of large amounts of data. In addition, existing power quality monitoring devices often have problems with large computational complexity and slow processing speed in data processing and analysis, which makes it difficult to meet application scenarios with high requirements for real-time performance and accuracy. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the existing power quality monitoring devices often have the problems of large amount of calculation and slow processing speed in data processing and analysis, which makes it difficult to meet the application scenarios with high requirements for real-time and accuracy. The purpose is to provide a DSP-based power quality monitoring device. Through the setting of the data acquisition unit, the voltage and current signals of multiple key nodes in the power grid can be collected in real time and accurately. The design of the signal conditioning unit fully considers the complexity and noise interference of the power grid signal; through the comprehensive use of the dual op amp noise reduction circuit, the reference bias circuit and the low-pass filter circuit, the device can effectively reduce noise and improve the signal-to-noise ratio and purity of the signal. The introduction of the multi-channel data processing unit enables the device to efficiently process a large amount of power grid data, thereby greatly improving the speed and efficiency of data processing; the DSP control unit, as the core component of the device, not only has a powerful data processing capability, but also has excellent coordination and control capabilities, realizing real-time monitoring of power quality and fault warning.

[0005] The present invention is achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a DSP-based power quality monitoring device, comprising:

[0007] A data acquisition unit, including voltage sensors and current sensors arranged at multiple key nodes in the power grid, for real-time acquisition of voltage and current signals at different locations in the power grid;

[0008] A signal conditioning unit, used for enhancing and filtering the collected voltage and current signals;

[0009] a multi-channel data processing unit, comprising a plurality of parallel processing channels, each channel being capable of independently processing an output signal from the signal conditioning unit;

[0010] A DSP control unit is used to execute control logic on the multi-channel data processing unit, coordinate the work of multiple processing channels, ensure synchronous data reception, and analyze and process the received data;

[0011] A power supply circuit control unit, which realizes the on-off state of the load power supply by connecting a thyristor in series in the power supply circuit, wherein the gate of the thyristor is connected to the control output terminal of the DSP control unit;

[0012] The communication unit is connected to the DSP control unit and is used to transmit the data processed by the DSP control unit to the monitoring center.

[0013] Furthermore, the signal conditioning unit includes:

[0014] A dual operational amplifier noise reduction circuit, used for performing noise reduction processing on the signal output by the data acquisition unit, and suppressing common mode noise through the differential amplification characteristics of the dual operational amplifier;

[0015] A reference bias circuit, used to provide a reference voltage for the dual operational amplifier noise reduction circuit;

[0016] The low-pass filter circuit is used to perform low-pass filtering on the amplified signal to obtain the low-frequency signal component after filtering out high-frequency noise and interference.

[0017] Furthermore, the dual op amp noise reduction circuit includes an op amp AR1 and an op amp AR2, the in-phase input terminal of the op amp AR1 is connected to a resistor R1 and one end of a capacitor C1, and is connected to the in-phase input terminal of the op amp AR2 and the output terminal of the reference bias circuit through a resistor R3, the other end of the resistor R1 is connected to the sensor signal output terminal of the data acquisition unit, and the other end of the capacitor C1 is grounded through a resistor R2; the output terminal of the op amp AR1 is connected to the in-phase input terminal of the op amp AR2 through a resistor R4; the inverting input terminal of the op amp AR2 is connected to the output terminal of the op amp AR2 and one end of a resistor R6 through a parallel resistor R5 and a capacitor C2, and the other end of the resistor R6 is connected to the inverting input terminal of the op amp AR1 through a capacitor C3.

[0018] Furthermore, the reference bias circuit includes a +5V power supply, which is connected to one end of an adjustable resistor RP1 through a resistor R7, and the other end of the adjustable resistor RP1 is grounded. The adjustment end of the adjustable resistor RP1 is connected to the cathode of a voltage-stabilizing diode DZ1, and is connected to the non-inverting input end of an op amp AR3 through a resistor R8, and the anode of the voltage-stabilizing diode DZ1 is grounded. The inverting input end and the output end of the op amp AR3 are connected to the non-inverting input end of the op amp AR2 and one end of a resistor R10 through a resistor R9, and the other end of the resistor R10 is grounded.

[0019] Furthermore, the low-pass filter circuit includes a resistor R11, a resistor R12 and a capacitor C4, one end of the resistor R12 and the capacitor C4 are connected to the output end of the operational amplifier AR2 and the input end of the multi-channel data processing unit, the other end of the capacitor C4 is connected to one end of the resistor R11, and the other end of the resistor R11 and the resistor R12 are grounded.

[0020] Furthermore, the multi-channel data processing unit includes:

[0021] An A / D converter is used to perform analog-to-digital conversion on the analog signal output by the signal conditioning unit, convert the analog signal into a digital signal, and send the digital signal to the DSP control unit for digital signal processing;

[0022] The data buffer is used to temporarily store the digital signal output by the A / D converter to ensure the continuity and integrity of the data and to buffer the processing pressure of the DSP control unit.

[0023] Furthermore, a protection component is provided between the thyristor and the DSP control unit.

[0024] Furthermore, the protection component includes a resistor R13, a voltage-stabilizing diode DZ2 and a capacitor C5, wherein one end of the resistor R13 is connected to the PWM control output end of the DSP control unit, the other end of the resistor R13 is connected to the cathode of the voltage-stabilizing diode DZ2, one end of the capacitor C5 and the gate of the thyristor, and the anode of the voltage-stabilizing diode DZ2 and the other end of the capacitor C5 are grounded.

[0025] Furthermore, the power supply circuit control unit also includes a thyristor Q1, a diode LED1, a resistor R14, a capacitor C6 and a connector J1; the base of the thyristor Q1 is connected to the resistor R13, the voltage-stabilizing diode DZ2 and the capacitor C5, the collector of the thyristor Q1 is connected to the positive electrode of LED1, the negative electrode of LED1 is grounded, and the emitter of the thyristor Q1 is connected to the resistor R14, the capacitor C6 and the connector J1 in sequence.

[0026] Furthermore, the communication unit is an RF wireless radio frequency module.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] Through the setting of the data acquisition unit, the voltage and current signals of multiple key nodes in the power grid can be collected in real time and accurately. The design of the signal conditioning unit fully considers the complexity of the power grid signal and the noise interference problem; through the comprehensive use of the dual op amp noise reduction circuit, the reference bias circuit and the low-pass filter circuit, this device can effectively reduce noise and improve the signal-to-noise ratio and purity of the signal. The introduction of the multi-channel data processing unit enables this device to efficiently process a large amount of power grid data, thereby greatly improving the speed and efficiency of data processing; the DSP control unit, as the core component of this device, not only has powerful data processing capabilities, but also has excellent coordination and control capabilities, realizing real-time monitoring of power quality and fault warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0030] Figure 1 A block diagram of the system module structure provided by an embodiment of the present invention;

[0031] Figure 2 A structural block diagram of a signal conditioning unit provided in an embodiment of the present invention;

[0032] Figure 3 A circuit schematic diagram of a signal conditioning unit provided by an embodiment of the present invention;

[0033] Figure 4 A circuit schematic diagram of a power supply circuit control unit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0035] As a possible implementation method, this embodiment provides a DSP-based power quality monitoring device. The above and other technical contents, features and functions of this embodiment are described in detail below with reference to Figures 1 to 4 The detailed description of the embodiments will clearly show that the structural contents mentioned in the following embodiments are all based on the drawings in the specification.

[0036] like Figure 1 As shown, the DSP-based power quality monitoring device includes:

[0037] A data acquisition unit, including voltage sensors and current sensors arranged at multiple key nodes in the power grid, for real-time acquisition of voltage and current signals at different locations in the power grid;

[0038] A signal conditioning unit, used for enhancing and filtering the collected voltage and current signals;

[0039] A multi-channel data processing unit, including a plurality of parallel processing channels, each channel being capable of independently processing an output signal from the signal conditioning unit;

[0040] DSP control unit, used to execute control logic on the multi-channel data processing unit, coordinate the work of each processing channel, ensure synchronous data reception, and analyze and process the received data;

[0041] The power supply circuit control unit realizes the on-off state of the load power supply by connecting a thyristor in series in the power supply circuit, and the gate of the thyristor is connected to the control output terminal of the DSP control unit;

[0042] The communication unit is connected to the DSP control unit and is used to transmit the data processed by the DSP control unit to the monitoring center.

[0043] In the above, the data acquisition unit monitors the key nodes of the power grid in real time, and obtains the original signals of voltage and current through voltage sensors and current sensors to ensure that various changes in the operation of the power grid can be fully captured.

[0044] In order to ensure the accuracy of power data monitoring, the signal conditioning unit performs necessary preprocessing on the collected raw signals. In order to adapt to complex signals in different power grid environments, such as Figure 2 As shown, the design of the signal conditioning unit includes:

[0045] The dual operational amplifier noise reduction circuit is used to perform noise reduction processing on the signal output by the data acquisition unit, suppress the common mode noise through the differential amplification characteristics of the dual operational amplifier, and improve the signal-to-noise ratio of the signal;

[0046] The reference bias circuit is used to provide a stable reference voltage for the dual op amp noise reduction circuit to ensure the accuracy and stability of signal processing;

[0047] The low-pass filter circuit is used to perform low-pass filtering on the amplified signal, filter out high-frequency noise and interference, and retain useful low-frequency signal components.

[0048] In a specific embodiment, if Figure 3As shown, the dual op amp noise reduction circuit includes an op amp AR1 and an op amp AR2, the in-phase input terminal of the op amp AR1 is connected to a resistor R1 and one end of a capacitor C1, and is connected to the in-phase input terminal of the op amp AR2 and the output terminal of the reference bias circuit through a resistor R3, the other end of the resistor R1 is connected to the sensor signal output terminal of the data acquisition unit, and the other end of the capacitor C1 is grounded through a resistor R2; the output terminal of the op amp AR1 is connected to the in-phase input terminal of the op amp AR2 through a resistor R4; the inverting input terminal of the op amp AR2 is connected to the output terminal of the op amp AR2 and one end of a resistor R6 through a parallel resistor R5 and a capacitor C2, and the other end of the resistor R6 is connected to the inverting input terminal of the op amp AR1 through a capacitor C3.

[0049] During the operation of the dual op amp noise reduction circuit, the sensor signal of the data acquisition unit is first filtered by RC to eliminate high-frequency noise, ensuring that only low-frequency signal components can pass smoothly. The output of the op amp AR1 is connected to the non-inverting input of the op amp AR2 through resistor R4 to form a differential amplifier circuit. This design utilizes the differential amplification characteristics of the op amp, which can effectively suppress common-mode noise, thereby improving the signal-to-noise ratio of the signal. At the same time, the inverting input of the op amp AR2 is connected to the capacitor C2 through a parallel resistor R5 to form a feedback network, which not only helps to stabilize the circuit, but also further suppresses noise. Resistor R6 and capacitor C3 form a closed-loop feedback compensation between the inverting input of the op amp AR1 and the output of the op amp AR2 to ensure that the final output signal is smoother and reduce signal distortion caused by high-frequency noise.

[0050] Furthermore, the in-phase input terminals of the operational amplifier AR1 and the operational amplifier AR2 are both connected to the output of the reference bias circuit, providing a stable reference voltage for the entire dual operational amplifier circuit, ensuring the accuracy and stability of signal processing. The reference bias circuit includes a +5V power supply, the +5V power supply is connected to one end of the adjustable resistor RP1 through a resistor R7, the other end of the adjustable resistor RP1 is grounded, the adjustment end of the adjustable resistor RP1 is connected to the cathode of the voltage zener diode DZ1, and is connected to the in-phase input terminal of the operational amplifier AR3 through a resistor R8, the anode of the voltage zener diode DZ1 is grounded, the inverting input terminal and the output terminal of the operational amplifier AR3 are connected to the in-phase input terminal of the operational amplifier AR2 and one end of the resistor R10 through a resistor R9, and the other end of the resistor R10 is grounded.

[0051] In addition, in order to improve the anti-interference ability of the device, the low-pass filter circuit is also designed in the signal conditioning unit circuit to further optimize the signal processing process. Through the filtering function of the resistor and capacitor elements, high-frequency noise is effectively filtered out to ensure the quality of the signal received by the data processing unit. Specifically, the low-pass filter circuit includes a resistor R11, a resistor R12 and a capacitor C4, one end of the resistor R12 and the capacitor C4 is connected to the output end of the operational amplifier AR2 and the input end of the multi-channel data processing unit, the other end of the capacitor C4 is connected to one end of the resistor R11, and the other ends of the resistor R11 and the resistor R12 are grounded.

[0052] The working process of the above signal conditioning unit circuit is a delicate signal processing process. Through differential amplification and filtering technology, the noise is effectively reduced and the purity of the signal is improved. The coordinated work of operational amplifiers AR1 and AR2 ensures that the signal can be sent to the back-end data processing system with higher quality after processing. The entire circuit design fully considers the integrity and stability of the signal, ensuring the reliable operation of the power quality monitoring device in various complex environments.

[0053] Due to the large scale and complexity of the power grid, it is necessary to monitor and process the data of multiple nodes in real time to ensure the stable operation of the power grid. The multi-channel data processing unit provides multiple parallel processing channels, each of which can independently receive and process the output signal from the signal conditioning unit, thereby greatly improving the speed and efficiency of data processing. Specifically, the multi-channel data processing unit includes:

[0054] A / D converter, used to perform analog-to-digital conversion on the analog signal output by the signal conditioning unit, convert the analog signal into a digital signal, and send it to the DSP control unit for digital signal processing;

[0055] The data buffer is used to temporarily store the digital signal output by the A / D converter to ensure the continuity and integrity of the data, while buffering the processing pressure of the DSP control unit.

[0056] In the specific working process, the data acquisition unit collects voltage and current signals at different locations in the power grid in real time through the voltage sensors and current sensors set in the power grid. These signals are enhanced and filtered by the signal conditioning unit to improve the quality and reliability of the signals. Then, the processed analog signals are sent to the A / D converter in the multi-channel data processing unit. The A / D converter converts these analog signals into digital signals for subsequent digital signal processing.

[0057] After the conversion, the digital signal is sent to the data buffer for temporary storage. The function of the data buffer is to ensure the continuity and integrity of the data, while buffering the processing pressure of the DSP control unit. In this way, the DSP control unit can further process and analyze the digital signal stored in the data buffer without time constraints.

[0058] In a specific embodiment, the DSP control unit starts and initializes, and loads necessary programs and configuration parameters. These programs and parameters are usually stored in a non-volatile memory to ensure that they are retained after the system is powered off. After the initialization is completed, the DSP control unit enters a standby state, waiting to receive instructions or data from the multi-channel data processing unit.

[0059] When the multi-channel data processing unit starts working, it will send the digital signal converted by the A / D converter into the data buffer for temporary storage. At the same time, the DSP control unit communicates with the multi-channel data processing unit through the internal bus or interface to obtain information about the status of the processing channel and data transmission. After ensuring that all processing channels are ready to receive data, the DSP control unit will issue a synchronous reception instruction. This instruction will trigger all processing channels in the multi-channel data processing unit to start receiving data at the same time. Since the DSP control unit has a strong coordination ability, it can ensure that each processing channel remains synchronized when receiving data, thereby avoiding data loss or misalignment.

[0060] During the data reception process, the DSP control unit will also perform real-time analysis and processing of the data, including pre-processing operations such as data filtering, noise reduction, and enhancement, as well as subsequent advanced processing tasks such as feature extraction and pattern recognition. In addition, the DSP control unit is also responsible for generating real-time monitoring reports and historical data analysis. Through the built-in timer, it can regularly generate statistical reports on power quality to help users understand long-term power quality trends.

[0061] In the system design, the DSP control unit also communicates with other systems by configuring the communication unit to achieve data sharing and remote monitoring. Specifically, the communication unit is an RF wireless radio frequency module. Through the RF wireless radio frequency module, the DSP control unit can transmit the data collected by the power quality monitoring device to the remote server or control center in real time. This wireless communication method not only improves the flexibility of data transmission, but also enhances the scalability of the system. Users can access this data from any location through the network for real-time monitoring and analysis.

[0062] In the specific control process of this application, the DSP control unit first analyzes the current, voltage and other parameters of the current power supply circuit according to the received power data, and determines whether they are within the normal range. If there are abnormal parameters, such as overcurrent, overvoltage, etc., the DSP control unit will immediately adjust the trigger angle of the thyristor Q1 to limit the increase of current and voltage, thereby protecting the safety of the power supply circuit and load equipment.

[0063] like Figure 4 As shown, a protection component is also arranged between the thyristor Q1 and the DSP control unit, and the protection component includes a resistor R13, a voltage-stabilizing diode DZ2 and a capacitor C5. One end of the resistor R13 is connected to the PWM control output end of the DSP control unit, and the other end of the resistor R13 is connected to the cathode of the voltage-stabilizing diode DZ2, one end of the capacitor C5 and the gate of the thyristor Q1. The anode of the voltage-stabilizing diode DZ2 and the other end of the capacitor C5 are grounded. Wherein, the power supply circuit control unit also includes the thyristor Q1, the diode LED1, the resistor R14, the capacitor C6 and the connector J1; the base of the thyristor Q1 is connected to the resistor R13, the voltage-stabilizing diode DZ2 and the capacitor C5, the collector of the thyristor Q1 is connected to the positive electrode of LED1, the negative electrode of LED1 is grounded, and the emitter of the thyristor Q1 is connected to the resistor R14, the capacitor C6 and the connector J1 in sequence. When the AC power supply is turned on, the current passes through R13, DZ2 and C5 to provide the base current for Q1, so that Q1 is turned on. After Q1 is turned on, the current passes through R14 and C6, and then through LED1, making LED1 light up, indicating that the circuit has power. The role of R14 and C6 may be to ensure that Q1 works stably at an appropriate voltage and reduce noise in the circuit. The voltage regulator diode DZ2 and capacitor C5 form a stable voltage reference point. During the operation of the system, if there is a voltage fluctuation or spike, DZ2 can respond quickly and stabilize the voltage within a safe range, thereby protecting the thyristor Q1 from damage. Capacitor C5 plays a filtering role in the circuit. It can smooth out the high-frequency noise in the PWM signal, ensure that the signal transmitted to the gate of the thyristor Q1 is clean and stable, and ensure the effectiveness of system control.

[0064] In summary, the present application can collect voltage and current signals of multiple key nodes in the power grid in real time and accurately through the setting of the data acquisition unit, and the design of the signal conditioning unit fully considers the complexity of the power grid signal and the noise interference problem. Through the comprehensive use of dual op amp noise reduction circuit, reference bias circuit and low-pass filter circuit, the present device can effectively reduce noise and improve the signal-to-noise ratio and purity of the signal. The introduction of the multi-channel data processing unit enables the present device to efficiently process a large amount of power grid data, thereby greatly improving the speed and efficiency of data processing. As the core component of the present device, the DSP control unit not only has powerful data processing capabilities, but also has excellent coordination and control capabilities, realizing real-time monitoring of power quality and fault warning.

[0065] In the description of the present application, it should be noted that the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0066] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0067] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0068] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0069] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0070] The above is a further detailed description of the present invention in combination with a specific implementation method, and it cannot be determined that the specific implementation of the present invention is limited to this; for technical personnel in the technical field to which the present invention belongs and related technical fields, based on the technical solution of the present invention, the expansion and replacement of operating methods and data should all fall within the protection scope of the present invention.

Claims

1. A DSP-based power quality monitoring device, characterized in that: include: A data acquisition unit, including voltage sensors and current sensors arranged at multiple key nodes in the power grid, for real-time acquisition of voltage and current signals at different locations in the power grid; A signal conditioning unit, used for enhancing and filtering the collected voltage and current signals; a multi-channel data processing unit, comprising a plurality of parallel processing channels, each channel being capable of independently processing an output signal from the signal conditioning unit; A DSP control unit is used to execute control logic on the multi-channel data processing unit, coordinate the work of multiple processing channels, ensure synchronous data reception, and analyze and process the received data; A power supply circuit control unit, which realizes the on-off state of the load power supply by connecting a thyristor in series in the power supply circuit, wherein the gate of the thyristor is connected to the control output terminal of the DSP control unit; The communication unit is connected to the DSP control unit and is used to transmit the data processed by the DSP control unit to the monitoring center.

2. The DSP-based power quality monitoring device according to claim 1 is characterized in that: The signal conditioning unit comprises: A dual operational amplifier noise reduction circuit, used for performing noise reduction processing on the signal output by the data acquisition unit, and suppressing common mode noise through the differential amplification characteristics of the dual operational amplifier; A reference bias circuit, used to provide a reference voltage for the dual operational amplifier noise reduction circuit; The low-pass filter circuit is used to perform low-pass filtering on the amplified signal to obtain the low-frequency signal component after filtering out high-frequency noise and interference.

3. The DSP-based power quality monitoring device according to claim 2 is characterized in that: The dual operational amplifier noise reduction circuit comprises an operational amplifier AR1 and an operational amplifier AR2; the in-phase input terminal of the operational amplifier AR1 is connected to a resistor R1 and one end of a capacitor C1, and is connected to the in-phase input terminal of the operational amplifier AR2 and the output terminal of the reference bias circuit through a resistor R3, the other end of the resistor R1 is connected to the sensor signal output terminal of the data acquisition unit, and the other end of the capacitor C1 is grounded through a resistor R2; the output terminal of the operational amplifier AR1 is connected to the in-phase input terminal of the operational amplifier AR2 through a resistor R4; the inverting input terminal of the operational amplifier AR2 is connected to the output terminal of the operational amplifier AR2 and one end of a resistor R6 through a parallel resistor R5 and a capacitor C2, and the other end of the resistor R6 is connected to the inverting input terminal of the operational amplifier AR1 through a capacitor C3.

4. The DSP-based power quality monitoring device according to claim 3 is characterized in that: The reference bias circuit includes a +5V power supply, which is connected to one end of an adjustable resistor RP1 through a resistor R7, and the other end of the adjustable resistor RP1 is grounded. The adjustment end of the adjustable resistor RP1 is connected to the cathode of a voltage-stabilizing diode DZ1, and is connected to the non-inverting input end of an op amp AR3 through a resistor R8, and the anode of the voltage-stabilizing diode DZ1 is grounded. The inverting input end and the output end of the op amp AR3 are connected to the non-inverting input end of the op amp AR2 and one end of a resistor R10 through a resistor R9, and the other end of the resistor R10 is grounded.

5. The DSP-based power quality monitoring device according to claim 4 is characterized in that: The low-pass filter circuit includes a resistor R11, a resistor R12 and a capacitor C4, one end of the resistor R12 and the capacitor C4 are connected to the output end of the operational amplifier AR2 and the input end of the multi-channel data processing unit, the other end of the capacitor C4 is connected to one end of the resistor R11, and the other ends of the resistor R11 and the resistor R12 are grounded.

6. The DSP-based power quality monitoring device according to claim 1, characterized in that: The multi-channel data processing unit comprises: An A / D converter is used to perform analog-to-digital conversion on the analog signal output by the signal conditioning unit, convert the analog signal into a digital signal, and send the digital signal to the DSP control unit for digital signal processing; The data buffer is used to temporarily store the digital signal output by the A / D converter to ensure the continuity and integrity of the data and to buffer the processing pressure of the DSP control unit.

7. The DSP-based power quality monitoring device according to claim 1, characterized in that: A protection component is also arranged between the thyristor and the DSP control unit.

8. The DSP-based power quality monitoring device according to claim 7, characterized in that: The protection component includes a resistor R13, a voltage-stabilizing diode DZ2 and a capacitor C5, wherein one end of the resistor R13 is connected to the PWM control output end of the DSP control unit, the other end of the resistor R13 is connected to the cathode of the voltage-stabilizing diode DZ2, one end of the capacitor C5 and the gate of the thyristor, and the anode of the voltage-stabilizing diode DZ2 and the other end of the capacitor C5 are grounded.

9. The DSP-based power quality monitoring device according to claim 8, characterized in that: The power supply circuit control unit also includes a thyristor Q1, a diode LED1, a resistor R14, a capacitor C6 and a connector J1; the base of the thyristor Q1 is connected to the resistor R13, the voltage-stabilizing diode DZ2 and the capacitor C5, the collector of the thyristor Q1 is connected to the positive electrode of the LED1, the negative electrode of the LED1 is grounded, and the emitter of the thyristor Q1 is connected to the resistor R14, the capacitor C6 and the connector J1 in sequence.

10. The DSP-based power quality monitoring device according to claim 1, characterized in that: The communication unit is an RF wireless radio frequency module.

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