CN108535575A - Power quality analysis device based on short-distance wireless communication technology - Google Patents

Abstract

The invention belongs to the technical field of power quality detection, in particular to a power quality analysis device based on short-distance wireless communication technology. The invention includes an analog signal conditioning circuit, an analog-to-digital converter, a waveform buffer, a digital signal processor, a main controller, a screen display module, a key module, a WIFI module, and a storage module; the input terminal of the analog-to-digital converter and the analog The output end of the signal conditioning circuit is connected, the output end of the analog-to-digital converter is connected with the input end of the waveform buffer; the input end of the digital signal processor is connected with the output end of the waveform buffer, and the output end of the digital signal processor is connected with the main The input terminal of the controller is connected; the main controller is bidirectionally connected with the WIFI module and the storage module respectively, and the screen display module and the button module are respectively electrically connected with the main controller. The invention facilitates the harmonic analysis by the digital signal processor, reduces the harmonic analysis error caused by spectrum leakage, improves the accuracy of the harmonic analysis, and meets the requirement of informatization.

Description

Power quality analysis device based on short-distance wireless communication technology

technical field

The invention belongs to the technical field of power quality detection, in particular to a power quality analysis device based on short-distance wireless communication technology.

Background technique

With the promotion and development of smart grids and distributed energy systems, power quality issues are becoming more and more prominent and important. The country has successively promulgated GB/T12325-2008 "Power Supply Voltage Allowable Deviation", GB/T15945-2008 "Power System Frequency Deviation", GB/15543-2008 "Power Quality_Three-phase Voltage Unbalance", GB/ T12326-2008 "Power Quality Voltage Fluctuation and Flicker" and other national standards. It can be seen that it is an important decision to respond to the country to accurately and reliably detect the power quality of each link. At present, most power quality monitoring devices are limited by the installation location after being installed on site, so it is inconvenient to view the data. Users cannot find wiring errors in time, cannot conveniently view and modify power quality thresholds, and cannot monitor power quality parameters in real time. The device of the present invention communicates with the smart phone, tablet computer PAD and host computer with on-site analysis software through the WIFI module, the data transmission speed is fast, and no wired connection is required, which not only saves costs, improves safety, but also improves work efficiency. The use of WIFI wireless communication has a high level of intelligence, flexible use, complete functions, reliable quality, good maintainability, and also meets the needs of personal and social informatization.

At present, most power quality monitoring devices use equal time intervals to sample the measured waveform instead of equal period sampling. The equal time interval sampling method has the problem of spectrum leakage when calculating harmonics, resulting in low accuracy of harmonic analysis.

Contents of the invention

The present invention aims to solve the relevant problems in the above-mentioned prior art, and proposes a power quality analysis device based on short-distance wireless communication technology. Power quality, fast transmission speed, and high safety, which not only saves costs for users, but also improves work efficiency. At the same time, the waveform resampling circuit is used to sample 4096 points per unit cycle of each sampling channel signal, and the output conforms to IEC6100 The -4-7 standard signal facilitates harmonic analysis by digital signal processors, reduces harmonic analysis errors caused by spectrum leakage, and improves the accuracy of harmonic analysis.

In order to realize the foregoing invention object, the present invention is achieved through the following technical solutions:

A power quality analysis device based on short-distance wireless communication technology, including an analog signal conditioning circuit, an analog-to-digital converter, a waveform buffer, a digital signal processor, a main controller, a screen display module, a key module, a WIFI module, and a storage module; The input end of the analog-digital converter is connected with the output end of the analog signal conditioning circuit, and the output end of the analog-digital converter is connected with the input end of the waveform buffer; the input end of the digital signal processor is connected with the waveform buffer The output terminal of the digital signal processor is connected with the input terminal of the main controller; the main controller is connected with the WIFI module and the storage module in both directions, and the screen display module and the button module are electrically connected with the main controller respectively .

The analog signal conditioning circuit inputs the voltage and current signals of the line under test, and after being processed by the analog signal conditioning circuit, the output signal is within the range required by the input of the analog-to-digital converter; the analog signal conditioning circuit is composed of voltage signal conditioning and current signal conditioning , The voltage signal conditioning is completed by a resistor divider sensor, and the current signal conditioning is completed by an electromagnetic current sensor with a feedback winding.

The analog signal output by the analog signal conditioning circuit is input to the analog-to-digital converter through the analog input channel, and the analog-to-digital converter adopts AD7616, and the analog signal is converted into a digital signal and delivered to the waveform buffer through SPI serial mode; AD7616 is 16 1-bit DAS, supports dual synchronous sampling for 16 channels, each channel has a sampling rate of 1 MSPS, each channel is independently configured as ±10 V, ±5 V, or ±2.5 V, chip-level analog input 8 kV ESD protection, With burst mode sampling, the sequence of sampling channels is free to pre-program, and the signal-to-noise ratio reaches 90.5 dB; the analog-to-digital converter has a built-in analog input clamp protection circuit, which can withstand the voltage of ±21 V. No matter what sampling frequency is used, the AD7616 The analog input impedance is 1 MΩ, and the analog-to-digital converter also has a built-in first-order anti-aliasing analog filter and digital filter.

The digital signal output by the analog-to-digital converter is connected to the input end of the waveform buffer through the SPI interface, and the waveform buffer first calculates the respective Ua, Ub, Uc, Un, Ia, Ib, Ic, and In signals output by the analog-to-digital converter. Then re-sample the waveform and output a signal conforming to the IEC6100-4-7 standard to ensure that each sampling channel collects exactly 4096 points in each cycle, and the collected data is transmitted to the digital signal processor through the SPI interface.

Described waveform buffer selects SPARTAN6 FPGA, and SPARTAN6 FPGA refers to Spartan6 series compilable integrated circuit FPGA, and this FPGA has double register 6 input look-up table LUT logic and built-in system level module; Utilize the phase-locked loop PLL of SPARTAN6FPGA to lock the measured waveform in real time frequency signal, resample the waveform of each sampling channel signal, calculate the period of each sampling channel signal, resample at 4096 points per period, and output a signal that conforms to the IEC6100-4-7 standard for digital signal processors Perform harmonic analysis.

The digital signal processor sends the collected and calculated power quality data to the main controller through the SPI interface; the digital signal processor locks the discrete signal output by the waveform buffer in real time, analyzes and calculates voltage, current, frequency, and harmonic voltage , harmonic current, harmonic power, flicker, three-phase unbalance; the digital signal processor chooses TMS320F28335, which is a 32-bit floating-point processor with a high-speed processing capability of 150MHz and a 32-bit floating-point processing unit. 6 DMA channels support ADC, McBSP and EMIF, with up to 18 channels of PWM output, of which 6 channels are TI's unique higher-precision PWM output HRPWM, 12-bit 16-channel ADC, with I ² C, SPI, eCAN , Epwm, LVDS and other bus interfaces; TMS320F28335 calculates the collected data, runs the power quality analysis algorithm conforming to the IEEE standard, obtains the power quality index data, and completes the power quality data collection and calculation; the indexes include: voltage, current, frequency , Harmonic voltage, harmonic current, harmonic power, flicker, three-phase unbalance.

The main controller is connected with the screen display module through the LVDS interface; the main controller is connected with the button module through the I ² C interface; the main controller is connected with the WIFI module through the SPI interface.

The main controller receives the power quality data calculated and processed by the digital signal processor and stores it in the storage module of the main controller. The main controller receives the instruction of the button module and sends the corresponding stored information to the screen display module for display. Communicate with the smart phone or tablet PAD with the on-site analysis software, and also communicate with the host computer.

The smart phone or tablet computer PAD is connected to the power quality analysis device through the WIFI network, checks the wiring mode of the power quality analysis device, and timely checks for wrong wiring; modifies and sets parameters such as the operation mode and power quality threshold of the power quality analysis device; Measure line power quality parameters; record historical data such as power quality events and working status changes; after returning to the studio, users can communicate with the host computer through the WIFI module to store stored power quality parameters, power quality events and working status Changes and other information are uploaded to the host computer for further analysis of power quality.

The display interface controlled by the button module includes: VAH mode, waveform diagram mode, power quality overview mode, swell and dip mode, harmonic mode, inter-harmonic mode, flicker mode, transient mode, unbalanced mode, power And power mode, inrush current mode, trigger parameter viewing mode; the display content of each mode is as follows: VAH mode can display various detailed measurements of the measured frequency and the measured voltage and current of each phase in the form of real-time measured values and trend graphs information; the power quality overview mode can obtain the overall situation of the power quality of the measured system; the swell and dip mode is used to capture sudden changes in the measured voltage such as dips, interruptions, and swells; the harmonic mode uses histograms and real-time measurement Value, and trend graph to provide detailed measurement information of measured voltage, current, and power harmonics; inter-harmonic mode provides bar graph, real-time measured value, and trend graph to provide inter-harmonics of measured voltage and current Wave detailed measurement information; flicker mode provides flicker measurement values in the form of real-time measurement values and trend graphs; transient mode helps users capture shock pulses and oscillations caused by sudden changes in voltage waveforms that last in microseconds; The unbalanced mode reflects the phase relationship of each phase voltage and current in the form of phasor diagrams, real-time measured values and trend diagrams; the power and electric energy mode provides detailed information on the power and electric energy of the power facility under test in the form of real-time measured values and trend diagrams. Measurement information; the inrush current mode provides users with a means to capture rapid and large current changes, that is, inrush current; the trigger parameter viewing mode displays various trigger parameters in the form of real-time measured values and trend graphs.

Compared with the prior art, the present invention has the beneficial effects of:

(1) A waveform buffer is used between the analog-to-digital converter and the digital signal processor to perform periodic calculations on the digital signal output by the analog-to-digital converter to ensure that each sampling channel provides exactly 4096 points per cycle, and the output conforms to IEC6100-4-7 standard signals are convenient for digital signal processors to perform harmonic analysis, reducing harmonic analysis errors caused by spectrum leakage and improving the accuracy of harmonic analysis.

(2) Communication through the WIFI module, with fast transmission speed, high security and high work efficiency. The waveform resampling circuit is used to facilitate harmonic analysis, reduce harmonic analysis errors caused by spectrum leakage, and improve the accuracy of harmonic analysis. The WIFI module can be connected to the smart phone or the tablet computer PAD, and the user only needs to use the smart phone or the tablet computer PAD to check the wiring line on site, set parameters and check the power quality parameters in real time, and communicate with the host computer through the WIFI module in the laboratory , to further analyze the power quality parameters, the data transmission speed is faster than other wireless communication methods, and no wired connection is required. Compared with traditional wired transmission methods, WIFI access is relatively safe and healthy, which not only saves costs, but also improves work efficiency. Using WIFI The wireless communication method has a high level of intelligence, flexible use, complete functions, reliable quality, and good maintainability, which also meets the needs of personal and social informatization.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Detailed ways

The following clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

As shown in Figure 1, the present invention is a power quality analysis device based on short-distance wireless communication technology, including an analog signal conditioning circuit, an analog-to-digital converter, a waveform buffer, a digital signal processor, a main controller, and a screen display module, key module, WIFI module, storage module; the input end of the analog-to-digital converter is connected with the output end of the analog signal conditioning circuit, and the output end of the analog-to-digital converter is connected with the input end of the waveform buffer; The input end of the digital signal processor is connected with the output end of the waveform buffer, and the output end of the digital signal processor is connected with the input end of the main controller; The module and the button module are respectively electrically connected to the main controller.

During specific implementation, the voltage and current signals of the line under test are input to the analog signal conditioning circuit, and after being processed by the analog signal conditioning circuit, the output signal is within the range required by the input of the analog-to-digital converter. The analog signal conditioning circuit is composed of voltage signal conditioning and current signal conditioning. The voltage signal conditioning is completed by a resistor divider sensor, and the current signal conditioning is completed by an electromagnetic current sensor with a feedback winding.

The analog signal output by the analog signal conditioning circuit is input to the analog-to-digital converter through the analog input channel. The analog-to-digital converter uses AD7616 to convert the analog signal into a digital signal and send it to the waveform buffer through SPI serial mode. AD7616 is a 16-bit DAS that supports dual simultaneous sampling of 16 channels, each channel sampling rate is up to 1 MSPS, each channel can be independently configured as ±10 V, ±5 V, or ±2.5 V, chip-level analog Input 8 kV ESD protection, with burst mode sampling, the order of sampling channels can be freely pre-programmed, the signal-to-noise ratio is as high as 90.5 dB, and the on-chip oversampling mode can be used to achieve higher SNR performance. The analog-to-digital converter has a built-in analog input clamp protection circuit, which can withstand voltages up to ±21 V. Regardless of the sampling frequency, the analog input impedance of the AD7616 is 1 MΩ. The analog-to-digital converter also has a built-in first-order anti-aliasing Stacked analog filter and digital filter to ensure the transmission rate and quality of the signal.

The digital signal output by the analog-to-digital converter is connected to the input terminal of the waveform buffer through the SPI interface. The waveform buffer first calculates the respective periods of the Ua, Ub, Uc, Un, Ia, Ib, Ic, and In signals output by the analog-to-digital converter , and then resample the waveform to output a signal conforming to the IEC6100-4-7 standard, ensuring that each cycle of each sampling channel collects exactly 4096 points, and the collected data is transmitted to the digital signal processor through the SPI interface. The waveform buffer facilitates harmonic analysis by the digital signal processor, reduces harmonic analysis errors caused by spectrum leakage, and improves the accuracy of harmonic measurement.

The waveform buffer chooses SPARTAN6 FPGA from XILINX. SPARTAN6 FPGA refers to the Spartan6 series compilable integrated circuit FPGA, which provides a new and more efficient dual-register 6-input look-up table LUT logic and a series of rich built-in system-level modules. Its phase-locked loop PLL can eliminate clock skew and duty cycle distortion, and can realize low-jitter clock control, and its frequency synthesizer can realize frequency multiplication, frequency division and phase modulation. The phase-locked loop PLL of SPARTAN6 FPGA can lock the frequency signal of the measured waveform in real time, resample the waveform of each sampling channel signal, calculate the period of each sampling channel signal, and resample at 4096 points in each period, and the output conforms to The signal of IEC6100-4-7 standard is convenient for digital signal processor to carry out harmonic analysis.

The digital signal processor sends the collected and calculated power quality data to the main controller through the SPI interface. The digital signal processor locks the discrete signal output by the waveform buffer in real time, analyzes and calculates voltage, current, frequency, harmonic voltage, harmonic current, harmonic power, flicker, and three-phase unbalance. The digital signal processor chooses TMS320F28335 of TI Company, which is a 32-bit floating-point processor with a high-speed processing capability of 150MHz, a 32-bit floating-point processing unit, and 6 DMA channels supporting ADC, McBSP and EMIF. There are 6 channels of PWM output, 6 of which are TI's unique higher-precision PWM output HRPWM, 12-bit 16-channel ADC, and bus interfaces such as I ² C, SPI, eCAN, Epwm, and LVDS. The digital signal processor has high precision, low cost, low power consumption, high performance, high peripheral integration, large data and program storage capacity, and more accurate and fast A/D conversion. TMS320F28335 calculates the collected data, runs the power quality analysis algorithm conforming to the IEEE standard, obtains the index data of power quality, and completes the collection and operation of the power quality data. Indicators include: voltage, current, frequency, harmonic voltage, harmonic current, harmonic power, flicker, three-phase unbalance.

The main controller is connected to the screen display module through the LVDS interface; the main controller is connected to the button module through the I ² C interface; the main controller is connected to the WIFI module through the SPI interface.

The working principle of the main controller is as follows: the main controller receives the power quality data calculated and processed by the digital signal processor, and stores it in the storage module of the main controller; The display module shows that the WIFI module communicates with the smart phone or tablet PAD with analysis software on site, and also communicates with the host computer.

The user connects the power quality analysis device with the smart phone or tablet computer PAD on site through the WIFI network, checks the wiring mode of the power quality analysis device, and timely checks for wrong wiring; modifies and sets the parameters such as the operation mode and power quality threshold of the power quality analysis device; real-time view Power quality parameters of the tested line; record historical data such as power quality events and work status changes; after returning to the studio, the user can communicate with the host computer through the WIFI module, and store the stored power quality parameters, power quality events and work Information such as state changes is uploaded to the host computer for further analysis of power quality. The power quality analysis device forms an integrated system with a smart phone, a tablet computer PAD or a host computer. Using this wireless communication method to replace manual on-site readings or wired connections not only saves costs but also improves work efficiency.

The main controller is Freescale Cortex-A9, quad-core i.MX6Q processor with a main frequency of 1GHz, 2GDDR3 memory, and 16GB EMMC storage.

The display interface controllable through the key module includes: VAH mode, waveform mode, power quality overview mode, swell and dip mode, harmonic mode, inter-harmonic mode, flicker mode, transient mode, unbalanced mode, power And energy mode, inrush current mode, trigger parameter viewing mode. The display content of various modes is as follows: VAH mode can display various detailed measurement information of the measured frequency and the measured voltage and current of each phase in the form of real-time measured values and trend graphs; the power quality overview mode can obtain the power quality of the measured system The overall situation; the sudden rise and fall mode is used to capture sudden changes in the measured voltage such as dips, interruptions and swells; the harmonic mode provides the measured voltage, current, The detailed measurement information of the harmonics of the voltage and current; the inter-harmonic mode provides the detailed measurement information of the measured voltage and current inter-harmonics in the form of histograms, real-time measured values, and trend graphs; the flicker mode provides real-time measured values and The flicker measurement value is provided in the form of a trend graph; the transient mode helps users capture the sudden change of the voltage waveform with a duration of microseconds caused by shock pulses and oscillations; the unbalance mode uses phasor diagrams, real-time measured values, and trend graphs The phase relationship of each phase voltage and current can be reflected in a unique way; the power and energy mode provides detailed measurement information of the power and energy of the power facility under test in the form of real-time measured values and trend graphs; the inrush current mode provides users with the ability to capture fast and large Current change, that is, the means of surge current; the trigger parameter viewing mode displays various trigger parameters in the form of real-time measured values and trend graphs.

Only the preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and can also be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. Various changes should be included within the protection scope of the present invention.

Claims (10)

1. A power quality analysis device based on short-distance wireless communication technology, characterized in that it includes an analog signal conditioning circuit, an analog-to-digital converter, a waveform buffer, a digital signal processor, a main controller, a screen display module, a key module, WIFI module, storage module; the input end of the analog-to-digital converter is connected with the output end of the analog signal conditioning circuit, and the output end of the analog-to-digital converter is connected with the input end of the waveform buffer; the digital signal processor The input end of the digital signal processor is connected with the output end of the waveform buffer, and the output end of the digital signal processor is connected with the input end of the main controller; Electrically connected with the main controller. 2. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the analog signal conditioning circuit inputs the voltage and current signal of the line under test, and the output signal is processed by the analog signal conditioning circuit It is the range required by the input of the analog-to-digital converter; the analog signal conditioning circuit is composed of voltage signal conditioning and current signal conditioning, the voltage signal conditioning is completed by a resistor divider sensor, and the current signal conditioning is completed by an electromagnetic current sensor with a feedback winding. 3. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the analog signal output by the analog signal conditioning circuit is input to the analog-to-digital converter through the analog input channel, and the analog-to-digital conversion The AD7616 is used as the converter to convert the analog signal into a digital signal and send it to the waveform buffer through SPI serial mode; AD7616 is a 16-bit DAS, which supports dual-channel synchronous sampling of 16 channels, and the sampling rate of each channel is 1 MSPS. Independently configured as ±10 V, ±5 V, or ±2.5 V, chip-level analog input 8 kV ESD protection, with burst mode sampling, free pre-programmed sampling channel sequence, signal-to-noise ratio up to 90.5 dB; built-in analog-to-digital converter The analog input clamp protection circuit can withstand the voltage of ±21 V. Regardless of the sampling frequency, the analog input impedance of the AD7616 is 1 MΩ. The analog-to-digital converter also has a built-in first-order anti-aliasing analog filter and digital filter device. 4. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the digital signal output by the analog-to-digital converter is connected to the input end of the waveform buffer through the SPI interface, and the waveform buffer first Calculate the respective periods of the Ua, Ub, Uc, Un, Ia, Ib, Ic, and In signals output by the analog-to-digital converter, then resample the waveform, and output signals that comply with the IEC6100-4-7 standard to ensure that each sampling channel Each cycle of the system collects exactly 4096 points, and the collected data is transmitted to the digital signal processor through the SPI interface. 5. the power quality analysis device based on short-distance wireless communication technology according to claim 1, is characterized in that: described waveform buffer selects SPARTAN6 FPGA, and SPARTAN6 FPGA refers to Spartan6 series compilable integrated circuit FPGA, and this FPGA has dual Register 6 inputs the look-up table LUT logic and built-in system-level modules; use the phase-locked loop PLL of SPARTAN6 FPGA to lock the frequency signal of the measured waveform in real time, resample the waveform of each sampling channel signal, and calculate the period of each sampling channel signal , resampling at 4096 points per cycle, and output signals conforming to the IEC6100-4-7 standard, so that the digital signal processor can perform harmonic analysis. 6. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the digital signal processor sends the collected and calculated power quality data to the main controller through the SPI interface; The digital signal processor locks the discrete signal output by the waveform buffer in real time, analyzes and calculates voltage, current, frequency, harmonic voltage, harmonic current, harmonic power, flicker, and three-phase unbalance; the digital signal processor chooses TMS320F28335, It is a 32-bit floating-point processor with 150MHz high-speed processing capability, 32-bit floating-point processing unit, 6 DMA channels supporting ADC, McBSP and EMIF, and up to 18 PWM outputs, of which 6 are TI's unique higher-precision PWM output HRPWM, 12-bit 16-channel ADC, with I ² C, SPI, eCAN, Epwm, LVDS and other bus interfaces; TMS320F28335 calculates the collected data and runs power quality analysis algorithms that meet IEEE standards. Obtain the index data of power quality, and complete the collection and calculation of power quality data; the indexes include: voltage, current, frequency, harmonic voltage, harmonic current, harmonic power, flicker, and three-phase unbalance. 7. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the main controller is connected to the screen display module through the LVDS interface; the main controller is connected to the key module through the ^I2C interface Connection; the main controller is connected to the WIFI module through the SPI interface. 8. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the main controller receives the power quality data calculated and processed by the digital signal processor, and stores it in the memory of the main controller module, the main controller receives the command of the button module, and sends the corresponding stored information to the screen display module for display. The WIFI module communicates with the smart phone or tablet PAD with analysis software on site, and also communicates with the host computer. 9. The power quality analysis device based on short-distance wireless communication technology according to claim 8, characterized in that: the smart phone or tablet computer PAD is connected to the power quality analysis device through a WIFI network, and the wiring mode of the power quality analysis device is checked, Timely check wrong wiring; modify and set parameters such as power quality analysis device operation mode and power quality threshold; view the power quality parameters of the tested line in real time; record historical data such as power quality events and working status changes; , the user can communicate with the host computer through the WIFI module, and upload the stored power quality parameters, power quality events, and work status changes to the host computer for further analysis of power quality. 10. The power quality analysis device based on short-distance wireless communication technology according to claim 1, characterized in that: the display interface controlled by the button module includes: VAH mode, waveform diagram mode, power quality overview mode, sudden rise Down mode, harmonic mode, inter-harmonic mode, flicker mode, transient mode, unbalanced mode, power and energy mode, inrush current mode, trigger parameter view mode; various modes are displayed as follows: VAH mode can be used The measured frequency and various detailed measurement information of the measured voltage and current of each phase are displayed in the form of real-time measured values and trend graphs; the power quality overview mode can obtain the overall situation of the power quality of the measured system; the swell and dip mode is used to Capture sudden changes in the measured voltage such as sags, interruptions, and swells; the harmonic mode provides detailed measurement information of the harmonics of the measured voltage, current, and power in the form of histograms, real-time measured values, and trend graphs; The harmonic mode provides detailed measurement information of the interharmonics of the measured voltage and current in the form of bar graphs, real-time measured values, and trend graphs; the flicker mode provides flicker measured values in the form of real-time measured values and trend graphs; The transient mode helps the user capture the sudden change of the voltage waveform with a duration of microseconds caused by shock pulses and oscillations; the unbalanced mode reflects the phase relationship of each phase voltage and current in the form of phasor diagrams, real-time measured values and trend diagrams ;The power and energy mode provides detailed measurement information of the power and energy of the power facility under test in the form of real-time measured values and trend graphs; the inrush current mode provides users with a means to capture rapid and large current changes, that is, inrush current; trigger The parameter viewing mode displays various trigger parameters in the form of real-time measured values and trend graphs.