CN201269907Y

CN201269907Y - Harmonic detector used between electrical power systems

Info

Publication number: CN201269907Y
Application number: CNU2008201001196U
Authority: CN
Inventors: 周念成; 赵渊; 谭桂华
Original assignee: Chongqing University
Current assignee: Chongqing University
Priority date: 2008-09-25
Filing date: 2008-09-25
Publication date: 2009-07-08
Anticipated expiration: 2018-09-25

Abstract

The utility model relates to a power system inter-harmonic detector which comprises a data analysis module, a switch power supply and a liquid crystal display (LCD). The input terminal of the data analysis module is connected with a signal acquisition circuit and the output terminal thereof is connected with a liquid crystal display circuit and a communication circuit; and the data analysis module is also connected with a clock holding circuit. The signal acquisition circuit consists of a PT or CT and an operational amplifier circuit connected with the PT or CT; the data analysis module consists of a digital signal processor (DSP), a 6M crystal oscillator connected with the XTAL1 terminal of the DSP and an oscillating capacitor; and a clock holding module consists of a clock chip, a 3.6V button cell connected with the clock chip, an oscillating capacitor and a 32.768K crystal oscillator. The power system inter-harmonic detector is used for the inter-harmonic detection of equipment such as a transformer substation and the like, can online collect the power system voltage and current signal, displays the component of the signal inter-harmonic on the LCD by data analysis and carries out data transmission by the intercommunication of the communication circuit and the computer, thereby realizing the function of detecting power system inter-harmonic in real time.

Description

Harmonic detector between a kind of electric system

Technical field

The utility model relates to the electric power quality pick-up unit, relates in particular to be used for the device that transformer station etc. is detected harmonic wave between the electric energy system.

Background technology

Usually people are defined as a harmonic wave to the voltage or the electric current that contain the non-integral multiple frequency of electric power system design and operation frequency (China is 50HZ); The basic reason that harmonic wave produces in the electric system is because due to the nonlinear load.A harmonic wave and a harmonic wave extensively exist in electric system, and the safe and stable operation of electrical network, user's normal electricity consumption and industrial and agricultural production caused seriously influence.Therefore, a Harmonious Waves in Power Systems and a harmonic problem have caused people's great attention.At present, Measurement of Harmonics in Power System can be implemented in line detected, many harmonic wave pick-up units have also been arranged.But to harmonic wave between electric system, since between harmonic wave to the relatively sensitive characteristic of spectrum leakage and be subjected to significantly characteristic of noise, cause a harmonic wave detection means less, and owing to the complicated reason of computing method, generally can only image data analyze, certain difficulty is arranged and implement online detection.At present, still lack harmonic detector between measuring accuracy height, the online fast electric system of detection.

Chinese patent (CN2932397) discloses an a kind of electric harmonic and a harmonic monitoring device, this device comprises the instrument voltage transformer group, the instrument current transformer group, A/D converter, a digital signal processor (DSP), a microcontroller (MCU), 2 program storage (program storages 1, program storage 2), the I/O controller, data-carrier store, communication control unit, display and keyboard, touch-screen and mouse, instrument voltage transformer group and instrument current transformer group constitute the three-phase voltage current sampling circuit, A/D converter is connected between sample circuit and the DSP, communicating by letter between DSP and the MCU adopted the HPI data bus, two program storages by bus respectively with DSP, MCU connects, data-carrier store is connected with MCU by bus, display and keyboard, touch-screen and mouse all are connected in the corresponding port of the I/O controller of MCU.Though this device has been realized the monitoring of a harmonic wave and a harmonic wave, but have the following disadvantages: first: employing be windowing FFT computing, there is the spectrum leakage problem in this algorithm, and a harmonic component has very high sensitivity to spectrum leakage, harmonic wave between the spectrum leakage of harmonic component might flood really, humorous corrugated is difficult to differentiate the accurate detection of harmonic wave between having had a strong impact between perhaps generation falseness; Second: communicating by letter between DSP and the MCU adopted HPI data bus, complex circuit; The 3rd: the monitoring device volume is too big, is not easy to carry.

The utility model content

At the deficiency that existing detection technique exists, the purpose of this utility model provides a kind of measuring accuracy height, detects fast, harmonic detector between the reliable electric system of testing result.

The purpose of this utility model is achieved in that harmonic detector between a kind of electric system, comprise data analysis module, Switching Power Supply and LCD, it is characterized in that: the input end of data analysis module connects signal acquisition circuit, and output terminal connects liquid crystal display circuit and telecommunication circuit; Data analysis module also connects the clock holding circuit;

Signal acquisition circuit is made up of PT or CT and coupled operation amplifier circuit; Data analysis module is made up of digital signal processor DSP, the 6M crystal oscillator and the oscillating capacitance that are connected in the XTAL1 end on this DSP;

The clock holding circuit mainly is made up of clock chip, the 3.6V button cell, oscillating capacitance and the 32.768K crystal oscillator that are connected on the clock chip.

The utility model is compared with conventional electric power system harmonics pick-up unit, has the following advantages:

(1) this harmonic detector reliability height, measuring accuracy height can detect by real-time online;

(2) this harmonic detector adopts advanced data analysing method, the non-integer harmonics in can test macro; And there is not the spectrum leakage problem;

(3) this harmonic detector video data and waveform in real time has the data hold function, handled easily and management;

(4) this harmonic detector has advantages such as measurement range is wide, cost performance is high, real-time is good, has solved the difficult problem that harmonic wave between present electric system detects, can be accurately, harmonic components and feature between reporting system timely, guarantee power supply safety;

(5) this harmonic detector has only used a DSP just can finish the work, and no longer adopts MCU, and is succinct, more reliable with respect to an electric harmonic and a harmonic monitoring device; It is little also to have volume, the easy to carry and characteristics being convenient to install.

Description of drawings

Fig. 1 is a functional-block diagram of the present utility model;

Fig. 2 is a signal acquisition circuit of the present utility model;

Fig. 3 is the utility model data analysis module and telecommunication circuit;

Fig. 4 is a clock holding circuit of the present utility model;

Fig. 5 is a software flow pattern of the present utility model.

Embodiment

The utility model is described in further detail below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, the utility model relates to harmonic detector between a kind of electric system, mainly comprises signal acquisition circuit 1, data analysis module 2, Switching Power Supply 3, clock holding circuit 4, display screen 5 and telecommunication circuit 6; It is based on harmonic detector between the electric system of dsp processor.Omit external structures such as housing and keyswitch among the figure.

Referring to Fig. 2, signal acquisition circuit (1) is made up of PT or CT and coupled operation amplifier circuit; The signal of collection PT of signal acquisition circuit elder generation or CT transmission is handled by the operational amplification circuit of forming with high precision operating amplifier MCP604 and peripheral element thereof, and the AD that sends into DSP changes mouth.

Referring to Fig. 3, be data analysis module and the telecommunication circuit of a kind of embodiment, data analysis module (2) is made up of DSP, the 6M crystal oscillator and the oscillating capacitance that are connected in the XTAL1 end of this DSP; Data analysis module (2) is a core with the DSP based on TMS320LF2407, and outer program storage of CY7C1021 matrix and peripheral circuit composition.DSP of the present utility model adopts the TMS320LF2407 of TI series, and it has, and arithmetic capability is strong, capacity big, advantage of high precision.Calculation process by DSP draws actual every phase voltage and current value, enter a harmonic wave simultaneously and detect processing, adopt Digital Signal Processing, with the data that record by methods such as interpolation FFT calculating obtain existing in the signal between the harmonic component parameter, and simultaneously sampled data and analysis result are deposited in the EEPROM of DSP.Its telecommunication circuit is made up of MAX202 communication chip, MAX485 communication chip and the peripheral circuit thereof of DSP, the RX that is connected in this DSP and TX end.

DSP among the design and operation amplifier circuit power supply employing+3.3V reach ± power supply of 12V power switch.

Referring to Fig. 4, clock holding circuit (4) is made up of clock chip PCF8583 and the 3.6V button cell, oscillating capacitance and the 32.768K crystal oscillator that are connected on the clock chip, to guarantee still have clock to keep function when power supply is interrupted.

Referring to Fig. 5, use the utility model, after obtaining analyzing data, can select by button, on LCD screen, show waveform and the parameter that records signal in real time, the waveform and the parameter of harmonic component by synchronous clock, can select to preserve at regular intervals the data and the analysis result that record between also can selecting only to show.If communication interface is inserted computer, the data and the analysis result that record in real time can be passed to computer immediately by communication chip MAX202, MAX485 processing, and make report form by the processing of daemon software and on INTERNET, issue.

This device be used for equipment such as transformer station between harmonic wave detect, but online acquisition power system voltage and current signal and by data analysis, the composition of harmonic wave in the middle of the shows signal on LCD screen, and carry out data transmission by telecommunication circuit and computing machine mutual communication, reach the function of harmonic wave between real-time detection electric system.This device has advantages such as measurement range is wide, reliability is high, cost performance is high, real-time is good, has solved the difficult problem that harmonic wave between present electric system detects, can be accurately, harmonic components and feature between reporting system timely, guarantee power supply safety.And this harmonic wave pick-up unit adopts power Spectral Estimation, and application PRONY method detects the amplitude and the phase place of a harmonic wave, and there is not the spectrum leakage problem in this detection method.

Claims

1, harmonic detector between a kind of electric system, comprise data analysis module (2), Switching Power Supply (3) and LCD, it is characterized in that: the input end of data analysis module (2) connects signal acquisition circuit (1), and output terminal connects liquid crystal display circuit (5) and telecommunication circuit (6); Data analysis module (2) also connects clock holding circuit (4);

Signal acquisition circuit (1) is made up of PT or CT and coupled operation amplifier circuit; Data analysis module (2) is made up of digital signal processor DSP, the 6M crystal oscillator and the oscillating capacitance that are connected in the XTAL1 end on this DSP;

Clock keeps module (4) to be made up of clock chip, the 3.6V button cell, oscillating capacitance and the 32.768K crystal oscillator that are connected on the clock chip.

2, harmonic detector between electric system according to claim 1 is characterized in that described digital signal processor DSP adopts the TMS320LF2407 chip.