CN216350936U - Harmonic early warning monitoring circuit and harmonic early warning monitoring device - Google Patents

Abstract

This application belongs to electric energy quality monitoring technology field, provides a harmonic early warning monitoring circuit, harmonic early warning monitoring devices, and harmonic early warning monitoring circuit includes: the device comprises a voltage monitoring module, a current monitoring module and a signal conversion module, wherein the voltage monitoring module is used for carrying out voltage mutual inductance on the power quality of a monitoring point to generate a voltage mutual inductance signal; the current monitoring module is used for carrying out current mutual inductance on the power quality of the monitoring point to generate a current mutual inductance signal; the signal conversion module is connected with the voltage monitoring module and the current monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module and converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module; through mutual inductance of voltage and mutual inductance of current to the monitoring point, the problem that the existing harmonic early warning monitoring device cannot detect the quality of electric energy in real time, so that local operation and maintenance personnel of a transformer substation cannot timely and effectively master the resonance condition of the transformer substation is solved.

Description

Harmonic early warning monitoring circuit and harmonic early warning monitoring device

Technical Field

The application belongs to the technical field of power quality monitoring, and particularly relates to a harmonic early warning monitoring circuit and a harmonic early warning monitoring device.

Background

With the construction and the promotion of the power internet of things, the demand of a power system on the power quality monitoring device is gradually increased, and various types of power quality monitoring devices are developed and put into the operation of a power grid. The power quality monitoring devices are characterized in that the power quality monitoring devices are high in point sampling rate, high in resolution and large in monitoring amount, are suitable for different scenes and meet the requirements of the power internet of things on edge calculation and intelligent terminals. However, in the current power internet of things, many functions are still needed but not realized in the power quality monitoring device, and only can be completed by a cloud or a data center.

Harmonic resonance is a stubborn and intractable problem that exists for a long time in the transformer substation, and not only the electric wire netting center dispatcher, the local fortune dimension personnel of transformer substation also need pay attention to constantly, but in prior art, has the problem that the harmonic early warning monitoring devices in the transformer substation can't be to electric energy quality real-time supervision can't be to electric energy quality real-time detection for the local fortune dimension personnel of transformer substation can't in time master the transformer substation resonance condition effectively.

SUMMERY OF THE UTILITY MODEL

An object of the application is to provide a harmonic early warning monitoring circuit, harmonic early warning monitoring devices, aim at solving current harmonic early warning monitoring devices and can not be to power quality real-time detection for the local operation and maintenance personnel of transformer substation can't in time master the problem of the transformer substation resonance condition effectively.

A first aspect of an embodiment of the present application provides a harmonic early warning monitoring circuit, which includes:

the voltage monitoring module is used for carrying out voltage mutual inductance on the power quality of the monitoring point to generate a voltage mutual inductance signal;

the current monitoring module is used for carrying out current mutual inductance on the power quality of the monitoring point to generate a current mutual inductance signal;

and the signal conversion module is connected with the voltage monitoring module and the current monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module and converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module.

Optionally, the voltage monitoring module includes a plurality of voltage transformers.

Optionally, the current monitoring module includes a plurality of current transformers.

Optionally, the signal conversion module includes a first analog-to-digital converter and a second analog-to-digital converter;

the first analog-to-digital converter is connected with the voltage monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module;

the second analog-to-digital converter is connected with the current monitoring module and used for converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module.

Optionally, the harmonic early warning monitoring circuit further includes:

and the isolation and filtering module is respectively connected with the voltage monitoring module, the current monitoring module and the signal conversion module and is used for filtering and isolating the voltage mutual inductance signal and the current mutual inductance signal.

A second aspect of the embodiments of the present application provides a harmonic early warning monitoring apparatus, including: the harmonic early warning monitoring circuit as described in any one of the above; further comprising:

the harmonic processing module is connected with the harmonic early warning monitoring circuit and used for generating the total harmonic content according to the voltage data signal and the current data signal;

and the comparison module is connected with the harmonic processing module, compares the total harmonic content with a preset harmonic threshold value, and generates a harmonic early warning signal when the total harmonic content is greater than the preset harmonic threshold value.

Optionally, the harmonic early warning monitoring apparatus further includes:

and the power supply module is connected with the harmonic processing module and the harmonic calculation module and used for providing electric energy for the harmonic processing module and the harmonic calculation module, wherein the power supply module internally comprises an alternating current-to-direct current circuit and a direct current conversion circuit.

Optionally, the harmonic early warning monitoring apparatus further includes:

and the internal storage module is connected with the harmonic processing module and is used for storing the total harmonic content and the harmonic processing result.

Optionally, the harmonic early warning monitoring apparatus further includes:

the lithium battery module is connected with the harmonic processing module; the harmonic processing module is used for supplying electric energy to the harmonic processing module when the power supply module stops working; and the number of the first and second groups,

a lithium battery residual electricity detection module; and the harmonic processing module is connected with the power supply and is used for detecting the voltage and the temperature of the lithium battery and compensating the temperature of the residual electricity of the lithium battery.

Optionally, the harmonic early warning monitoring apparatus further includes:

and the display module is connected with the harmonic processing module and is used for displaying the generated harmonic early warning signal.

The embodiment of the application provides a harmonic early warning monitoring circuit, harmonic early warning monitoring devices, wherein, harmonic early warning monitoring circuit includes: the device comprises a voltage monitoring module, a current monitoring module and a signal conversion module, wherein the voltage monitoring module is used for carrying out voltage mutual inductance on the power quality of a monitoring point to generate a voltage mutual inductance signal; the current monitoring module is used for carrying out current mutual inductance on the power quality of the monitoring point to generate a current mutual inductance signal; the signal conversion module is connected with the voltage monitoring module and the current monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module and converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module; through mutual inductance of voltage and mutual inductance of current to the monitoring point, the problem that the existing harmonic early warning monitoring device cannot detect the quality of electric energy in real time, so that local operation and maintenance personnel of a transformer substation cannot timely and effectively master the resonance condition of the transformer substation is solved.

Drawings

Fig. 1 is a schematic diagram of a harmonic warning monitoring circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of another harmonic warning and monitoring circuit provided in the embodiment of the present application;

fig. 3 is a schematic diagram of another harmonic warning and monitoring circuit provided in the embodiment of the present application;

fig. 4 is a schematic structural diagram of a harmonic early warning monitoring apparatus provided in an embodiment of the present application;

fig. 5 is a schematic structural diagram of another harmonic early warning and monitoring device provided in the embodiment of the present application;

fig. 6 is a schematic structural diagram of another harmonic early warning and monitoring device provided in the embodiment of the present application;

fig. 7 is a specific schematic diagram of a harmonic early warning monitoring device provided in the embodiment of the present application.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Harmonic resonance is a persistent and troublesome problem in the electric power transportation system of the electric network, and the generation of harmonics is caused by the presence of nonlinear loads (harmonic sources) in the electric network, such as: power transformers and reactors, thyristors, arc furnaces, rotating electrical machines, household appliances, etc., and in addition, when resonance occurs in the system, harmonic waves are also generated, however, the resonance occurs due to the presence of energy storage elements such as inductances and capacitances in the power system, in some cases, for example: the voltage transformer is in ferromagnetic saturation, a non-full-phase switch is switched on, one phase of the transmission line is disconnected, one end of the transmission line is grounded, and the like, so that resonance is formed in a partial circuit.

Harmonics may also resonate in certain circumstances, and a resonant circuit of a certain harmonic may be formed by the harmonic source and the device or devices in the system. Due to the existence of harmonic resonance, the waveform of voltage and current is distorted, which may cause the loss increase of electrical equipment such as transformers and rotating electrical machines, the insulation aging of capacitors is accelerated, the service life is shortened, and the like, and cause the hazards of relay protection and automatic devices in the system such as malfunction or rejection, interference of communication signals, and the like.

In the prior art, most power systems adopt filter devices to eliminate the harmonic waves, and the resonance can cause overvoltage and overcurrent in a certain range of the system; the resonance overvoltage not only harms the insulation of equipment, but also generates large zero sequence voltage component, false grounding and incorrect grounding indication occur, and the asynchronous motor with small capacity is reversed; in the past, a power quality monitoring device in a transformer substation cannot perform early warning, analysis and evaluation on harmonic resonance, so that local operation and maintenance personnel in the transformer substation cannot timely and effectively master the resonance condition of the transformer substation.

In order to solve the above technical problem, an embodiment of the present application provides a harmonic early warning monitoring circuit, which is shown in fig. 1 and includes: a voltage monitoring module 10, a current monitoring module 20 and a signal conversion module 30.

In the embodiment of the present application, the voltage monitoring module 10 is configured to perform voltage mutual inductance on the power quality of a monitoring point, so as to generate a voltage mutual inductance signal; the current monitoring module 20 is used for carrying out current mutual inductance on the power quality of a monitoring point to generate a current mutual inductance signal; the signal conversion module 30 is connected to the voltage monitoring module 10 and the current monitoring module 20, and is configured to convert the voltage mutual inductance signal into a voltage data signal and send the voltage data signal to the harmonic calculation module 40, and convert the current mutual inductance signal into a current data signal and send the current data signal to the harmonic calculation module 40.

Specifically, in the embodiment of the present application, the voltage monitoring module 10 and the current monitoring module 20 may simultaneously monitor mutual inductance conditions of voltage and current of two monitoring points, wherein each monitoring point may be provided with 4 paths of voltage transformers and 4 paths of current transformers simultaneously, and acquire 16 paths of voltage mutual inductance signals and current mutual inductance signals simultaneously; then the mutual inductance signal of multichannel voltage and the mutual inductance signal of electric current that will gather convey signal conversion module 30, signal conversion module 30 will receive mutual inductance signal of voltage and mutual inductance signal of electric current through filtering, go out the noise etc. convert analog signal into corresponding digital signal and convey harmonic calculation module 40, 8 way voltage and 8 way electric currents sample simultaneously has been realized, through the configuration, a device can monitor two power quality monitoring points simultaneously, solved current harmonic early warning monitoring devices can not detect the power quality in real time, make local operation and maintenance personnel of transformer substation can in time master the transformer substation resonance condition effectively.

In one embodiment, referring to fig. 1 and 7, the harmonic calculation module 40 may be an industrial chip XC7S100 from XILINX corporation, which is a low power consumption, small-package FPGA chip having 102400 logic units and 400I/O pins, and is low in price, sufficient in performance, rich in I/O resources, and capable of effectively reducing the manufacturing cost of the device while improving the overall performance of the device.

In one embodiment, referring to fig. 7, the harmonic calculation module 40 includes two parts, one part uses a conventional Fast Fourier Transform (FFT) method to calculate various standard power quality index data, such as the content of each harmonic, voltage deviation, frequency deviation, and imbalance; in the resonance early warning, when the total harmonic content exceeds a set threshold, a resonance risk exists at a monitoring point, the level and the probability of the resonance risk are improved along with the improvement of the total harmonic content, but because the increase of the harmonic is not necessarily caused by resonance, an additional criterion is needed; for the resonance in the branch, viewed from the monitoring point, the branch is equivalent to a resistor, the reactive current of the monitoring point is greatly reduced, and the active current is greatly increased, and for the resonance generated by the branch and the system in series, viewed from the harmonic power supply side, the total current of the resonance loop is a resistive current, but because the branch is a capacitive or inductive branch, the voltage of the branch leads or lags the resistive current by 90 degrees, at the monitoring point, the voltage is taken as the reference, the monitored reactive current is greatly increased, and the active current is greatly reduced; for other types of harmonic increase, the difference between the harmonic content and the active and reactive currents is small, and the reactive current and the active current of the branch are increased synchronously due to the harmonic increase, so that when the ratio of the reactive current to the active current is greatly changed (usually, the branch resonates with the system, namely, the ratio of the reactive current to the active current is greatly increased), the resonance risk and probability of the branch are greatly increased. Compared with the FFT method, the method has the advantages of small calculation amount, high calculation speed and short required sampling period.

In one embodiment, as shown with reference to fig. 1 and 7, the voltage monitoring module 10 includes a multi-way voltage transformer.

In this embodiment, the voltage monitoring module 10 may be an AD7606 chip, and 8 voltage transformers may be simultaneously disposed on two monitoring points to monitor voltage mutual inductance signals of corresponding points, where the AD7606 is a 16-bit synchronous sampling analog-digital data acquisition system, and has 8 channels, and each channel includes an analog input clamp protection, a Programmable Gain Amplifier (PGA), a low pass filter, a 16-bit Successive Approximation Register (SAR), and an analog-to-digital converter (ADC). The AD7606 further includes a flexible digital filter, a low drift, 2.5V precision reference voltage source and a reference voltage buffer for driving the ADC and flexible parallel and serial interfaces, and after 8 paths of voltage mutual inductance signals at the monitoring point are processed by the signal conversion module 30, the processed voltage signals are transferred to the harmonic calculation module 40.

In one embodiment, and as shown with reference to fig. 1 and 7, the current monitoring module 20 includes a multi-way current transformer.

Specifically, in this embodiment, the current monitoring module 20 may be an AD7606 chip, and may set 8 current transformers on two monitoring points simultaneously, monitor the mutual current inductance signal of the corresponding point, sample through built-in current transformer and monitoring point monitoring signal, amplify through the conditioning circuit, isolate and transmit to AD7606 after filtering, realize sampling at most 8 voltage simultaneously, through the configuration, a device may monitor the mutual current inductance signal of two power quality monitoring points simultaneously.

In one embodiment, referring to fig. 2, the signal conversion module 30 includes a first analog-to-digital converter 31 and a second analog-to-digital converter 32.

In the embodiment of the present application, the first analog-to-digital converter 31 is connected to the voltage monitoring module 10, and is configured to convert the voltage mutual inductance signal into a voltage data signal and send the voltage data signal to the harmonic calculation module 40; the second analog-to-digital converter 32 is connected to the current monitoring module 20, and is configured to convert the current mutual inductance signal into a current data signal, and send the current data signal to the harmonic calculation module 40.

Specifically, the 8-path voltage transformer transmits the monitored voltage mutual inductance signal to a first analog-to-digital converter 31 in the signal conversion module 30, the first analog-to-digital converter 31 converts the received analog voltage mutual inductance signal into a digital voltage mutual inductance signal and transmits the digital voltage mutual inductance signal to the harmonic calculation module 40, and the analog-to-digital conversion is generally processed through four processes of sampling, holding, quantizing and encoding and converted into a corresponding binary number to be output; sampling is to change continuously changing analog quantity into discrete digital quantity by using an analog switch, because the width of the digital quantity formed after sampling is narrow, narrow pulses can be widened by a holding circuit to form trapezoidal waves, and quantization is to convert each voltage value in a stepped analog signal into integral multiple of a certain minimum unit, so that the digital quantity can be conveniently used for representing; the coding is to express the quantized result (namely, the integral multiple value) by using binary number, so that the analog-to-digital conversion is realized in the process, and the problem that the existing harmonic early warning monitoring device cannot detect the quality of electric energy in real time is solved, so that local operation and maintenance personnel of the transformer substation can timely and effectively master the resonance condition of the transformer substation.

In one embodiment, referring to fig. 3, the harmonic pre-warning monitoring circuit further includes: and the isolation and filtering module 50 is respectively connected with the voltage monitoring module 10, the current monitoring module 20 and the signal conversion module 30, and is used for filtering and isolating the voltage mutual inductance signal and the current mutual inductance signal.

Specifically, in the process of signal transmission, it is often necessary to effectively filter a frequency point of a specific frequency in a circuit or frequencies other than the frequency point to obtain a power signal of the specific frequency, or to eliminate the power signal of the specific frequency, and filtering is generally performed by setting a capacitor, a resistor and an inductor, and the filtering is a circuit or an arithmetic processing system having a frequency selection function and has functions of filtering noise and separating various different signals; the circuit isolation mainly aims to cut off a path of noise interference through an isolation component, so that the effect of suppressing the noise interference is achieved. After the circuit isolation measure is adopted, most circuits can obtain a good noise suppression effect, so that the equipment meets the requirement of electromagnetic compatibility, and the problem that the existing harmonic early warning monitoring device cannot detect the quality of electric energy in real time, so that local operation and maintenance personnel of a transformer substation cannot timely and effectively master the resonance condition of the transformer substation is solved.

The embodiment of the present application further provides a harmonic early warning monitoring device, as shown in fig. 4, including: the harmonic wave early warning monitoring circuit comprises a harmonic wave early warning monitoring circuit; further comprising: a harmonic processing module 60 and a comparison module 70.

Specifically, the harmonic processing module 60 is connected to the harmonic warning and monitoring circuit, and is configured to generate a total harmonic content according to the voltage data signal and the current data signal; the comparing module 70 is connected to the harmonic processing module 60, compares the total harmonic content with a preset harmonic threshold, and generates a harmonic warning signal when the total harmonic content is greater than the preset harmonic threshold.

In one embodiment, the harmonic Processing module 60 may be an industrial-grade chip OMAP-L138, which is a low-power floating-point Digital Signal Processor (DSP) + ARM9 processor, and has rich peripheral interfaces, so as to fully meet the requirements of power applications for high-integration peripherals and low power consumption; the harmonic warning monitoring device has the advantages that the functions of resonance evaluation, analysis and early warning are realized through the OMAP-L138, the method for monitoring the change of the ratio of reactive power to active power is adopted, the advantages of fast calculation and short required sampling period of an instantaneous reactive power method are combined, the harmonic accident can be warned more quickly and accurately, the resonance branch can be automatically cut through the cooperation of a DI/DO interface and a protection device, the full automation of resonance early warning and elimination is realized, the problem that the existing harmonic warning monitoring device cannot detect the electric energy quality in real time, and the transformer substation local operation and maintenance personnel cannot timely and effectively master the resonance condition of the transformer substation is solved.

In one embodiment, as shown with reference to fig. 5, the harmonic warning monitoring apparatus further includes a power module 80.

Specifically, the power module 80 is connected with the harmonic processing module 60 and is used for providing electric energy for the harmonic processing module 60, wherein the power module 80 internally comprises an alternating current-to-direct current circuit and a direct current conversion circuit, an alternating current power supply is additionally arranged outside the power module 80, the input amplitude is 95-250V, the allowable deviation is +/-10%, and the frequency is 47-440 Hz; the power module 80 adopts two modularized power conversion circuits of alternating current to direct current (AC/DC) and direct current to direct current (DC/DC), the DC direct current output by the AC/DC power conversion circuit is three-level levels of ± 12V and 0V, and is used for driving a ± 12V type chip and circuit in the monitoring device and providing 24V input power for the DC/DC power conversion circuit, and the DC/DC power conversion circuit provides 5V, 3.3V and 1.8V DC power for the rest parts of the monitoring device; and a forward conducting diode is additionally arranged at the outlet of the DC/DC power conversion circuit, and a power failure detection signal is led to the harmonic processing module 60, and when external alternating current is lost, the harmonic processing module 60 detects the power failure detection signal and starts a power failure emergency processing flow.

In one embodiment, referring to fig. 6 and 7, the harmonic warning monitoring device further includes an internal storage module 90.

Specifically, the internal storage module 90 is connected to the harmonic processing module 60, and is configured to store the total harmonic content and the harmonic processing result. The internal storage module 90 includes a nonvolatile Ferroelectric Memory (FRAM), a nonvolatile flash Memory technology of an SPI Interface, a nonvolatile flash Memory technology mounted on an External storage Interface (EMIFA), and a SATA mechanical hard disk with a built-in capacity of 500 GB; the device realizes the classified storage of different data through abundant internal storage device combinations; the FRAM has the fastest speed and the most expensive price and is used for storing configuration parameters and power failure information of the device; NORFLASH mounted on EMIFA has large capacity and high speed, and is used for an embedded real-time system and application software of a storage device; the NORFLASH speed of the SPI interface is lower, and the NORFLASH speed is used for storing factory configuration parameters and demonstration data of the device; the SATA interface has the largest mechanical hard disk capacity and is used for locally storing real-time monitoring data of the power quality and evaluation reports and alarm information of resonance early warning; a large 500GB mechanical hard disk is arranged in the transformer substation, massive power quality monitoring data and resonance early warning data can be stored, and tracking and investigation of historical data by transformer substation operation and maintenance personnel are guaranteed.

In one embodiment, referring to fig. 6, the harmonic pre-warning monitoring device further includes a lithium battery module 100 and a lithium battery remaining power detection module 101.

Specifically, the lithium battery module is connected to the harmonic processing module 60; for supplying power to the harmonic processing module when the power module 80 stops operating; the lithium battery residual electricity detection module 101 is connected to the harmonic processing module 60, and is configured to detect the voltage and temperature of the battery, and perform temperature compensation on the residual electricity of the lithium battery.

In one embodiment, a spare lithium battery is arranged in the circuit and used for storing harmonic processing data, harmonic early warning data and the like during power failure, and the lithium battery residual electricity monitoring module can be an STC3100 chip and used as a main chip of the lithium battery residual electricity detection module and can be used for simultaneously detecting the voltage and the temperature of the lithium battery and performing temperature compensation on the residual electricity of the lithium battery; after the lithium battery is electrified for the first time, the residual electricity of the lithium battery can be corrected through a complete battery charging and discharging process; the current of 2.5A can be supported and detected to the maximum extent, and the sampling resistor is a precision resistor; when external alternating current is lost, the lithium battery is put into use, and after the device starts an emergency power-down process, the device can sequentially turn off the display module 110, the signal input/output module 140, the frequency measurement module 150, part of the communication interface module 120 and the like according to the residual power of the battery in order to ensure the processing and the storage of the power-down information by the device.

In one embodiment, referring to fig. 6 and 7, the harmonic warning monitoring apparatus further includes a display module 110.

Specifically, the display module 110 is connected to the harmonic processing module 60 and configured to display the generated harmonic warning signal, where the display module 110 includes an LCD display panel, an indicator light, and a function key.

In one embodiment, the display module 110 includes an LCD liquid crystal display, 13-way buttons, and 3 indicator lights; the LCD can display the power quality monitoring result of the device in real time in a form of a table, a curve or a histogram (pie chart), and can also display the result of the resonance evaluation in real time, indicate the resonance risk and the trend of each monitoring branch in a form of a table or a curve, and give out resonance alarm information; 6 of the 13-channel keys are matched with an LCD (liquid crystal display) screen to realize the rapid switching and changing of the functions and the configuration of the device, and the other 7 channels are respectively an upper channel, a lower channel, a left channel, a right channel, a confirmation channel, a retreat channel and a reset channel, wherein the reset key is pressed for a long time to start or shut down; the operation is instructed respectively to 3 way pilot lamps, communication and resonance are reported an emergency and asked for help or increased vigilance, operation pilot lamp and WATCHDOG cooperation scintillation when harmonic early warning monitoring devices is in normal operating, the operation pilot lamp does not dodge then means the device crashes, operation pilot lamp system starts and lights promptly, the communication pilot lamp lights and shows that the communication link is established, the scintillation then shows being in the communication, the resonance is reported an emergency and is lighted the existence that the device forecasts high resonance risk branch road, the scintillation shows that the resonance incident is taking place, need handle immediately, when the resonance is reported an emergency and is glimmed, LCD liquid crystal display will automatically switch to resonance branch road show corresponding electric energy quality monitoring result and resonance analysis report. Through button and LCD liquid crystal display's cooperation, can make the quick switching to required data interface of fortune dimension personnel, audio-visual electric energy quality monitoring result and the resonance risk aassessment of knowing the monitoring point, analysis results, through signal indicator lamp and LCD liquid crystal display's linkage, make fortune dimension personnel obtain resonance early warning and analysis results in the very first time, it can not be to electric energy quality real-time detection to have solved current harmonic early warning monitoring devices, make the local fortune dimension personnel of transformer substation can't in time master the problem of the transformer substation resonance condition effectively.

In one embodiment, referring to fig. 7, the harmonic warning monitoring apparatus further includes a communication interface module 120.

In this embodiment, the communication interface module 120 includes an RS485 interface, a USB interface, and an Ethernet interface, and can meet the requirements of various field communication tasks through an expanded external storage device CF card, and has rich communication interfaces, and can perform data exchange in different ways.

Specifically, the RS485 interface is connected to a UART interface of the harmonic processing module 60, the USB is connected to a USB interface of the harmonic processing module 60, and the Ethernet interface is connected to an MII interface of the harmonic processing module 60.

In one embodiment, referring to fig. 7, the harmonic warning monitoring apparatus further includes a time synchronization module 130.

The specific time tick module 130 adopts a mode of cooperative work of 1EEE 1588 protocol time tick and GPS second pulse time tick, the OMAP-L138 realizes the initial synchronization with an external clock through an Ethernet interface and an IEEE 1588 protocol, transmits the clock to the Xilinx XC7S100, simultaneously provides GPS second pulse signals to the OMAP-L138 and the Xilinx XC7S100, and corrects the clock through the GPS second pulse to improve the time precision; if the device cannot acquire the GPS pulse per second signal, the device can only adopt the IEEE 1588 protocol for time synchronization, and the time precision of the device is reduced at the moment; the GPS second pulse signal is provided from the outside; the clocks of the harmonic processing module 60 and the harmonic calculation module 40 are calibrated by the GPS second pulse, so that the clock accuracy is improved, and compared with a mode in which only the harmonic processing module 60 is calibrated and the harmonic calculation module 40 obtains the clock from the harmonic processing module 60, the clock accuracy of the harmonic calculation module 40 is greatly improved.

In one embodiment, as shown with reference to fig. 7, the harmonic pre-warning monitoring apparatus further includes a signal input/output module 140.

In this embodiment, the signal input/output module (DI/DO)140 provides input and output of the switching value signal, and can implement a plurality of different functions by customizing the switching value, the output signal of the default configuration of the device is a resonance alarm signal, for example, a high level indicates a high resonance risk, a low level indicates a low resonance risk, the input signal of the default configuration of the harmonic warning monitoring device is a protection action signal, a high level indicates a protection action, and a low level indicates a protection non-action.

In one embodiment, referring to fig. 7, the harmonic pre-warning monitoring device further includes a frequency measurement module 150.

Specifically, the frequency measurement module 150 implements fast measurement of the frequency of the monitoring signal through zero-crossing detection, and the method does not require FFT calculation, has a small amount of calculation and a fast speed, and is used in cooperation with the harmonic calculation module 40 (instantaneous reactive power method) to fast obtain the frequency and the total harmonic content of the monitoring signal.

In an embodiment, referring to fig. 7, the harmonic early warning monitoring apparatus further includes a time synchronization module 130, which corrects the IEEE 1588 clock received by the harmonic processing module 60 by using the GPS synchronous pulse-per-second signal, so as to improve the clock accuracy of the harmonic calculation module 40.

In one embodiment, the power module 80 is connected to an external input power source through two ac power lines, and provides ± 12V and its common ground 0V (SGND), 5V, 3.3V, 1.8V and its common ground 0V (DGND) to the inside of the device, where SGND and DGND are isolated from each other.

In one embodiment, referring to FIG. 7, harmonic processing module 60 passes through I²I of C interface and lithium battery residual electricity detection module 101²Exchanging data by the interface C, and acquiring the residual electric quantity information of the built-in lithium battery of the device; the interface is also connected with an I2C interface of the FRAM chip through multiplexing to acquire configuration information and power-down information of the device or power-down information of the storage device; harmonic processing module 60 also passes through I²Multiplexing of C interface and I of RTC chip DS3231²The interface C is connected to realize the functions of a calendar and a clock; the built-in power failure protection function automatically records power failure information to the FRAM when a power failure accident happens, so that the subsequent power failure accident analysis is facilitated.

In one embodiment, as shown in fig. 6 and 7, the harmonic processing module 60 is connected to a mechanical hard disk built in the apparatus through an SATA interface to store mass power quality monitoring data and resonance evaluation data, and is connected to an SPI FLASH through an SPI interface to store demonstration data and factory configuration parameters, and the NOR FLASH through the SPI interface stores the demonstration data; an RS485 signal is output through a UART interface, so that an RS485 communication interface is realized; the USB communication interface is realized by connecting the USB interface with the USB A-type female port; the Ethernet communication interface is realized by connecting an MII interface with a PHY chip LXT971 and connecting the LXT971 with an RJ45 interface.

In one embodiment, as shown in fig. 6 and 7, the harmonic processing module 60 is connected to the 13-way key, the 3-way LED indicator, the DI/DO interface terminal socket and the GPS interface terminal socket respectively through multiplexing of the GPIO ports, so as to implement functions of the key, the indicator, the DI/DO interface and input of GPS second pulse time-tick signals; the WATCHDOG function is realized by connecting the multiplexing GPIO port with the WATCHDOG chip SP706SEN, and the device is ensured to be automatically restarted in time after the halt; the output of multiplexing GPIO port and zero-crossing detection circuit links to each other, realizes the quick frequency measurement of monitoring point, and zero-crossing detection circuit adopts opto-coupler chip EL817S1 to carry out the alternating current-direct current and keeps apart to introduce the direct current loop with alternating current loop' S interference, harmonic processing module 60 links to each other with LCD liquid crystal display through the LCDC interface, realizes the large-size screen display, shows electric energy quality monitoring result and resonance risk assessment result locally.

In one embodiment, as shown in fig. 6 and 7, the harmonic processing module 60 is connected to a DDR2 SDRAM chip MT47H128M16 through a DDR2 interface, provides up to 256M of memory for a built-in system of the device, is connected to a CF card socket (50pin, card reader connector) through an EMIFA interface, and reads and writes an external CF card by using chip select CS 2; a1 GB NOR FLASH is also hung on the EMIFA interface and used for storing an embedded system and an application program, the chip selection CS5 is used for selection, the harmonic processing module 60 is connected with the harmonic calculation module 40(Xilinx XC7S100) through the EMIFA interface, and the chip selection CS0 is used for selection.

In one embodiment, as shown in fig. 6 and fig. 7, the harmonic processing module 60 opens a dual-port RAM area inside through a hardware programming language, and is connected with the harmonic processing module 60 through the dual-port RAM area for data exchange.

In one embodiment, as shown in fig. 6 and 7, the harmonic processing module 60 internally implements a GPS correction-based time synchronization module 130 through a hardware programming language, and corrects the IEEE 1588 clock received by the harmonic processing module 60 by using a GPS synchronous pulse per second signal, so as to improve the clock accuracy of the harmonic calculation module 40.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules, so as to perform all or part of the functions described above. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, a module or a unit may be divided into only one logical function, and may be implemented in other ways, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be realized by a computer program, which can be stored in a computer-readable storage medium and can realize the steps of the embodiments of the methods described above when the computer program is executed by a processor. . Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution medium, and the like. It should be noted that the computer readable medium may contain content that is subject to appropriate increase or decrease as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media does not include electrical carrier signals and telecommunications signals as is required by legislation and patent practice.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A harmonic early warning monitoring circuit, comprising:

the voltage monitoring module is used for carrying out voltage mutual inductance on the power quality of the monitoring point to generate a voltage mutual inductance signal;

the current monitoring module is used for carrying out current mutual inductance on the power quality of the monitoring point to generate a current mutual inductance signal;

and the signal conversion module is connected with the voltage monitoring module and the current monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module and converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module.

2. The harmonic pre-warning monitoring circuit of claim 1 wherein the voltage monitoring module comprises a multi-way voltage transformer.

3. The harmonic pre-warning monitoring circuit of claim 1 wherein the current monitoring module comprises a multi-way current transformer.

4. The harmonic pre-warning monitoring circuit of claim 1 wherein the signal conversion module comprises a first analog-to-digital converter and a second analog-to-digital converter;

the first analog-to-digital converter is connected with the voltage monitoring module and used for converting the voltage mutual inductance signal into a voltage data signal and sending the voltage data signal to the harmonic calculation module;

the second analog-to-digital converter is connected with the current monitoring module and used for converting the current mutual inductance signal into a current data signal and sending the current data signal to the harmonic calculation module.

5. The harmonic pre-warning monitoring circuit of claim 1, further comprising:

and the isolation and filtering module is respectively connected with the voltage monitoring module, the current monitoring module and the signal conversion module and is used for filtering and isolating the voltage mutual inductance signal and the current mutual inductance signal.

6. A harmonic early warning monitoring device, comprising: the harmonic pre-warning monitoring circuit of any one of claims 1 to 5; further comprising:

the harmonic processing module is connected with the harmonic early warning monitoring circuit and used for generating the total harmonic content according to the voltage data signal and the current data signal;

and the comparison module is connected with the harmonic processing module, compares the total harmonic content with a preset harmonic threshold value, and generates a harmonic early warning signal when the total harmonic content is greater than the preset harmonic threshold value.

7. The harmonic pre-warning monitoring device of claim 6, further comprising:

and the power supply module is connected with the harmonic processing module and the harmonic calculation module and used for providing electric energy for the harmonic processing module and the harmonic calculation module, wherein the power supply module internally comprises an alternating current-to-direct current circuit and a direct current conversion circuit.

8. The harmonic pre-warning monitoring device of claim 6, further comprising:

and the internal storage module is connected with the harmonic processing module and is used for storing the total harmonic content and the harmonic processing result.

9. The harmonic pre-warning monitoring device of claim 6, further comprising:

the lithium battery module is connected with the harmonic processing module; the harmonic processing module is used for supplying electric energy to the harmonic processing module when the power supply module stops working; and the number of the first and second groups,

a lithium battery residual electricity detection module; and the harmonic processing module is connected with the power supply and is used for detecting the voltage and the temperature of the lithium battery and compensating the temperature of the residual electricity of the lithium battery.

10. The harmonic pre-warning monitoring device of claim 6, further comprising:

and the display module is connected with the harmonic processing module and is used for displaying the generated harmonic early warning signal.

Images