CN1328586C - Electric energy quality monitoring, recording and analyzing system - Google Patents

Abstract

The invention relates to a power quality monitoring and recording analysis system, which belongs to a system for monitoring, recording and analyzing power quality. The invention mainly solves the technical difficulties of high price, single function and poor monitoring and analysis quality existing in the existing power quality monitoring device. For realizing above-mentioned task, the technical solution that the present invention adopts is: power quality monitoring record analysis system, it is made up of data acquisition module, data processing and analysis module, data display output module and man-machine interface module, the output end of data acquisition module and The input end of the data processing and analysis module is connected, the input end of the data display output module is connected with the output end of the data processing and analysis module, the output end of the man-machine interface module is connected with the control interface of the data processing and analysis module and the data display output module input connection. The invention has the advantages of powerful database management, analysis and statistics function of measurement data, multi-network function and the like.

Description

Power quality monitoring record analysis system

technical field

The invention relates to a power quality monitoring and recording analysis system, which belongs to a system for monitoring, recording and analyzing power quality.

Background technique

In modern industrial enterprises and transportation sectors, non-linear electrical loads are increasing substantially. With the development of power electronics technology, thyristor rectification and commutation technology has been widely used. For example, thyristor rectifier power supplies are widely used in metallurgy, chemical industry and mining departments, frequency conversion speed control devices are widely used in industry, and AC single-phase rectification is used in electrified railways. Powered locomotives, converter stations in high-voltage and large-capacity DC transmission, frequency conversion of household appliances, etc., have caused a sharp increase in the load on the power grid. In particular, the continuous growth of impact and non-linear load capacity causes power quality problems such as waveform distortion and voltage fluctuations in the power grid. The power sector must not only meet the increasing demand of users for the quantity of electric energy, but also provide electric energy of qualified quality. In order to solve the above problems, people have developed some related instruments and meters with relatively single functions, such as harmonic analyzers, voltage fluctuation and flicker monitoring devices, etc., because these devices are very expensive and cannot be widely used. In addition, they also have defects such as single function and poor quality of monitoring and analysis.

Contents of the invention

The purpose of the present invention is to solve the technical difficulties of high price, single function and poor monitoring and analysis quality existing in existing power quality monitoring devices, and to provide a power quality monitoring record analysis system with low price, complete functions and high monitoring and analysis quality.

In order to achieve the above tasks, the technical solution adopted by the present invention is: a power quality monitoring record analysis system, which is composed of a data acquisition module, a data processing and analysis module, a data display output module and a man-machine interface module, wherein:

1) The data acquisition module consists of four voltage sensors, at least sixteen current sensors, several analog switches, several holding circuits, several signal correction circuits and multiple data acquisition cards, four voltage sensors and at least sixteen The current sensor is connected to the input end of the analog switch, the output end of the analog switch is connected to the input end of the holding circuit, the output end of the holding circuit is connected to the input end of the signal correction circuit, and the output end of the signal correction circuit is connected to the input end of the data acquisition card Connection, the output end of the data acquisition card is connected with the input end of the data processing and analysis module;

The holding circuit is composed of chip LF398 U9, resistors R1, R2, R3, variable resistor RW1, and capacitors C1, C2, C3, C4, and C5. One end of resistor R1 is connected to 3 ends of chip U9, and the other end of resistor R1 Connect to the output terminal of the analog switch, one end of the resistor R2 is grounded, the other end of the resistor R2 is connected to a fixed end of the variable resistor RW1, the other fixed end of the variable resistor RW1 is connected to one end of the capacitor C1 and then connected to the chip U9 The 1 terminal of the variable resistor RW1 is connected to the +12V power supply, the movable terminal of the variable resistor RW1 is connected to the 2 terminals of the chip U9, the other terminal of the capacitor C1 is grounded, one terminal of the capacitor C2 is connected to the 4 terminal of the chip U9 and connected to the -12V power supply, and the capacitor The other end of C2 is grounded, one end of capacitors C4 and C5 is connected in series with one end of capacitor C3 and connected with terminal 6 of chip U9, the other end of capacitors C4 and C5 is connected in series with the other end of capacitor C3 and then grounded, chip U9 Terminal 7 of the resistor R3 is grounded, one terminal of the resistor R3 is connected to terminal 8 of the chip U9, the other terminal of the resistor R3 is connected to the +5V power supply, and terminal 5 of the chip U9 is the output terminal;

The signal correction circuit is composed of chips LM1558 U10A, LM1558 U10B, resistors R4, R5, R6, R7, R8, R9, variable resistor RW2, capacitors C6, C7, C8, C9, diodes D1, D2, regulator Z1 and The transient voltage suppressor T1 is composed of one end of the resistor R4 connected to the 5-terminal of the holding circuit chip U9, the other end of the resistor R4 is connected to the cathode of the diode D1, the anode of the diode D2, one end of the resistors R5, R6 and one end of the capacitor C7 Then connect to terminal 3 of chip U10A, connect the anode of diode D1 to the negative pole of diode D2 and then connect to terminal 2 of chip U10A, connect one terminal of capacitor C6 to one terminal of resistor R7 and then connect terminal 2 of chip U10A, and connect the other terminal of capacitor C6 to terminal 2 of chip U10A The other end of the resistor R7 is connected to ground, one fixed end of the variable resistor RW2 is connected to the other end of the resistor R5, the other fixed end of the variable resistor RW2 is connected to the movable end of the variable resistor RW2, and then connected to end 1 of the chip U10A , the other end of the capacitor C7 is connected to the other fixed end of the variable resistor RW2, the other end of the resistor R6 is connected to the movable end of the variable resistor RW2, the + terminal of the chip U10A is connected to the +12V power supply, the - terminal of the chip U10A is connected to - 12V power supply, one end of resistor R8 is connected to terminal 1 of chip U10A, the other end of resistor R8 is connected to one end of capacitor C8 and then connected to terminal 6 of chip U10B, the other end of capacitor C8 is grounded, and terminal 5 of chip U10B is connected to terminal 6 of chip U10B One end of resistor R9 is connected to end 7 of chip U10B, the other end of resistor R9 is connected to the negative pole of voltage regulator tube Z1, the negative pole of transient voltage suppressor T1 and one end of capacitor C9, and then multi-channel data acquisition The input terminal of the card, the positive pole of the voltage regulator tube Z1, the positive pole of the transient voltage suppressor T1 and the other end of the capacitor C9 share the ground;

2) The data processing and analysis module is composed of industrial control computer and data analysis software. The voltage and current values collected by the data acquisition module are processed by the data processing and analysis module using wavelet analysis method to perform harmonic calculation analysis, power calculation, voltage and current After calculation and power factor calculation, output to the data display output module;

3) The data display output module is composed of a liquid crystal display and a display output software module. The input end of the liquid crystal display is connected to the output end of the data processing and analysis module, so that the data output by the data processing and analysis module and the commands of the man-machine interface module display;

4) The man-machine interface module is composed of industrial control software and industrial control peripheral equipment. The output end of the man-machine interface module is connected with the control interface of the data processing and analysis module and the input end of the data display output module, so as to transmit user commands to Data processing and analysis module and data display output module.

The four-way voltage sensors V1, V2, V3, and V4 are WB3V411S voltage isolation sensors. The VGA, VGB, and VGC terminals of the sensor are connected to the S1～S4, S11～S14 terminals of the analog switch MAX309 U7 and the S11～S11～ of the analog switch MAX309 U8. S14 terminal connection.

The current sensors I1-I16 of at least sixteen circuits are WB3I411S current isolation sensors, and the VGA, VGB, and VGC terminals of the sensors are connected to the NO1-NO8 terminals of the analog switches MAX308 U1-U6.

The multi-channel data acquisition card has a gain 12-bit A/D conversion function, the sampling rate is 100KS/s, the gain of each input channel can be programmed, and the card integrates a 4k sampling FIFO buffer. The acquisition card will correct the circuit After the corrected signals are converted by the A/D, they are input into the data processing and analysis module for recording and analysis.

The industrial control computer is an industrial computer.

The industrial control peripherals include optical drive, floppy drive, keyboard and mouse.

Because the present invention has adopted above-mentioned technical scheme, compared with background technology, has following advantage:

1. It can monitor as many as 4 three-phase voltages of different voltage levels and at least 16 three-phase currents. It can quickly and comprehensively understand the various conditions of the power quality of the power grid, and capture and record various transient waveforms of the power grid. , to realize real-time monitoring of various power quality parameters of the power grid and real-time automatic online monitoring on site.

2. It has powerful database management and measurement data analysis and statistics functions. Through the management and analysis of the collected data, the power grid frequency, voltage (current) effective value, each harmonic voltage and current effective value, and phase can be obtained. Fundamental wave power, fundamental wave and harmonic impedance, three-phase voltage and current unbalance, equivalent positive sequence, negative sequence, zero sequence voltage and current, three-phase voltage fluctuation and other grid parameters, provide detection for power supply and users And judge the basis of power quality.

3. The wavelet analysis method is used to make the power quality evaluation more accurate and perfect; when the detected signal fails or is in a special situation, the signal will undergo a sudden change, and the signal fault and the operating state of the power quality can be analyzed by detecting these sudden changes Analyze, judge and control. After using the wavelet analysis method, these mutation signals can be detected and analyzed, which makes the power quality in the power quality monitoring and analysis system more accurate.

4. It has multi-network functions. Through the system's built-in MODEM, Ethernet, network card, serial port and other data transmission methods (such as telephone line, RS232, 485, RTU, etc.), with the corresponding application software, it can be easily interconnected with the power information network or INTERNET . Online maintenance can be realized through the Internet, and multi-network management of power quality can be realized.

5. With multi-channel control output function and low price.

Description of drawings

Fig. 1 is a structural block diagram of the present invention;

Figure 2 is a circuit diagram of the data acquisition module.

Detailed ways

As shown in Figure 1, the power quality monitoring record analysis system in this embodiment is composed of a data acquisition module, a data processing and analysis module, a data display output module and a man-machine interface module, wherein:

1) The data acquisition module consists of four voltage sensors, at least sixteen current sensors, six analog switches, nine holding circuits, nine signal correction circuits and multiple data acquisition cards, four voltage sensors and at least sixteen The current sensor is connected to the input end of the analog switch, the output end of the analog switch is connected to the input end of the holding circuit, the output end of the holding circuit is connected to the input end of the signal correction circuit, and the output end of the signal correction circuit is connected to the input end of the data acquisition card Connection, the output end of the data acquisition card is connected with the input end of the data processing and analysis module;

2) The data processing and analysis module is composed of an integrated industrial computer (AWS8248VT) and data analysis software. The voltage and current values collected by the data acquisition module are processed by the data processing and analysis module using the wavelet analysis method to perform harmonic calculation analysis and power calculation respectively. , Voltage and current calculation, power factor calculation and output to the data display output module;

3) The data display output module is composed of a 15-inch large-screen liquid crystal display and a software module for displaying output. The input end of the liquid crystal display is connected to the output end of the data processing and analysis module, so that the data output by the data processing and analysis module and the man-machine The commands of the interface module are displayed;

4) The man-machine interface module is composed of industrial control software and industrial control peripherals including optical drive, floppy drive, keyboard and mouse. The output end of the man-machine interface module is connected to the control interface of the data processing and analysis module and the input end of the data display output module , so as to transmit user commands to the data processing and analysis module and the data display and output module.

As shown in Figure 2, the above-mentioned four-way voltage sensors V1, V2, V3, and V4 are WB3V411S voltage isolation sensors, and the VGA, VGB, and VGC terminals of the sensor are connected to the S1~S4, S11~S14 terminals of the analog switch U7 (MAX309) and The S11-S14 ends of the analog switch U8 (MAX309) are connected.

As shown in Figure 2, the at least sixteen current sensors I1-I16 are WB3I411S current isolation sensors, and the VGA, VGB, and VGC terminals of the sensor are connected to the NO1-NO8 terminals of the analog switches U1-U6 (MAX308).

As shown in Figure 2, the above-mentioned nine-way holding circuit is composed of six-way current and three-way voltage holding circuits, each holding circuit consists of chip U9 (LF398), resistors R1, R2, R3, variable resistor RW1 and capacitor C1, Composed of C2, C3, C4, and C5, one end of the resistor R1 is connected to the 3-terminal of the chip U9, the other end of the resistor R1 is connected to the output end of the analog switch, one end of the resistor R2 is grounded, and the other end of the resistor R2 is connected to the variable resistor RW1 One fixed end of the variable resistor RW1 is connected to one end of the capacitor C1 and then connected to the 1st end of the chip U9 and connected to the +12V power supply. The movable end of the variable resistor RW1 is connected to the 2nd end of the chip U9 Connect, the other end of capacitor C1 is grounded, one end of capacitor C2 is connected to terminal 4 of chip U9 and connected to -12V power supply, the other end of capacitor C2 is grounded, and one end of capacitor C4 and C5 is connected in series with one end of capacitor C3 and connected to chip U9 The 6 terminals of the capacitor C4 and C5 are connected in series, the other terminal of the capacitor C4 is connected to the other terminal of the capacitor C3 and grounded, the 7 terminal of the chip U9 is grounded, one terminal of the resistor R3 is connected to the 8 terminal of the chip U9, and the other terminal of the resistor R3 is connected to the + The 5V power supply is connected, and the 5 terminal of the chip U9 is the output terminal.

As shown in Figure 2, the above-mentioned nine-way signal correction circuit is composed of six-way current and three-way voltage signal correction circuits, each signal correction circuit consists of chips U10A (LM1558), U10B (LM1558), resistors R4, R5, R6, Composed of R7, R8, R9, variable resistor RW2, capacitors C6, C7, C8, C9, diodes D1, D2, voltage regulator tube Z1 and transient voltage suppressor T1, one end of resistor R4 is connected to 5 ends of holding circuit chip U9 Connection, the other end of the resistor R4 is connected to the negative pole of the diode D1, the positive pole of the diode D2, one end of the resistors R5 and R6, and one end of the capacitor C7, and then connected to the 3 terminals of the chip U10A, and the positive pole of the diode D1 is connected to the negative pole of the diode D2. The 2 ends of the chip U10A, one end of the capacitor C6 is connected to one end of the resistor R7 and then connected to the 2 ends of the chip U10A, the other end of the capacitor C6 is connected to the other end of the resistor R7 and grounded, and a fixed end of the variable resistor RW2 is connected to the resistor R5 The other end of the variable resistor RW2 is connected to the movable end of the variable resistor RW2 and then connected to end 1 of the chip U10A, the other end of the capacitor C7 is connected to the other fixed end of the variable resistor RW2, and the resistor R6 The other end of the variable resistor RW2 is connected to the active end of the variable resistor RW2, the + terminal of the chip U10A is connected to the +12V power supply, the - terminal of the chip U10A is connected to the -12V power supply, one end of the resistor R8 is connected to the 1 end of the chip U10A, and the other end of the resistor R8 Connect one end of capacitor C8 to terminal 6 of chip U10B, the other end of capacitor C8 is grounded, terminal 5 of chip U10B is connected to terminal 7 of chip U10B, one end of resistor R9 is connected to terminal 7 of chip U10B, and the other end of resistor R9 The other end is connected to the negative pole of the Zener tube Z1, the negative pole of the transient voltage suppressor T1 and one end of the capacitor C9, and then connected to the input terminal of the multi-channel data acquisition card, the positive pole of the Zener tube Z1, and the positive pole of the transient voltage suppressor T1 Common ground with the other end of capacitor C9.

As shown in Figure 2, the above-mentioned data acquisition card is a multi-channel data acquisition card (PCI-1710L), which has a 12-bit A/D conversion function with a sampling rate of 100KS/s, and the gain of each input channel can be programmed. A 4k sampling FIFO buffer is integrated on the board, and the acquisition card inputs the signals of each channel corrected by the correction circuit into the data processing and analysis module for recording and analysis after the A/D conversion.

Claims (6)

1, a kind of electric energy quality monitoring, recording and analyzing system, it is made up of data acquisition module, data processing and analysis module, data presentation output module and human-machine interface module, it is characterized in that:

1) data acquisition module is by four road voltage sensors, at least ten No. six current sensors, several analog switches, the several holding circuit, several peaking circuit and multi-channel data acquisition card constitute, four road voltage sensors are connected with the input end of analog switch with at least ten No. six current sensors, the output terminal of analog switch is connected with the input end of holding circuit, the output terminal of holding circuit is connected with the input end of peaking circuit, the output terminal of peaking circuit is connected with the input end of data collecting card, and the output terminal of data collecting card is connected with the input end of data processing and analysis module;

Described holding circuit is by chip LF398 U9, resistance R 1, R2, R3, variable resistor RW1 and capacitor C 1, C2, C3, C4, C5 forms, one end of resistance R 1 is connected with 3 ends of chip U9, the other end of resistance R 1 is connected with the output terminal of analog switch, one end ground connection of resistance R 2, the other end of resistance R 2 is connected with the stiff end of variable resistor RW1, another stiff end of variable resistor RW1 be connected with 1 end of chip U9 again after an end of capacitor C 1 is connected and be connected with+12V power supply, the movable end of variable resistor RW1 is connected with 2 ends of chip U9, capacitor C 1 other end ground connection, one end of capacitor C 2 is connected with 4 ends of chip U9 and connects-the 12V power supply, the other end ground connection of capacitor C 2, capacitor C 4 is connected with an end of capacitor C 3 and is connected with 6 ends of chip U9 with C5 series connection back one end, capacitor C 4 is connected back ground connection with its other end of C5 series connection back with the other end of capacitor C 3, the 7 end ground connection of chip U9, one end of resistance R 3 is connected with 8 ends of chip U9, the other end of resistance R 3 is connected with+5V power supply, and 5 ends of chip U9 are output terminal;

Described peaking circuit is by chip LM1558 U10A, LM1558 U10B, resistance R 4, R5, R6, R7, R8, R9, variable resistor RW2, capacitor C 6, C7, C8, C9, diode D1, D2, stabilivolt Z1 and Transient Voltage Suppressor T1 form, one end of resistance R 4 is connected with 5 ends of holding circuit chip U9, the negative pole of the other end of resistance R 4 and diode D1, the positive pole of diode D2, resistance R 5, the end of R6 and 3 ends that meet chip U10A after an end of capacitor C 7 is connected, the positive pole of diode D1 and 2 ends that meet chip U10A after the negative pole of diode D2 is connected, one end of capacitor C 6 and 2 ends that meet chip U10A after an end of resistance R 7 is connected, the other end of capacitor C 6 is connected back ground connection with the other end of resistance R 7, the stiff end of variable resistor RW2 is connected with the other end of resistance R 5, another stiff end of variable resistor RW2 and 1 end that meets chip U10A after the movable end of variable resistor RW2 is connected, the other end of capacitor C 7 is connected with another stiff end of variable resistor RW2, the other end of resistance R 6 is connected with the movable end of variable resistor RW2, chip U10A+termination+12V power supply, chip U10A-termination-12V power supply, one end of resistance R 8 is connected with 1 end of chip U10A, the other end of resistance R 8 is connected the back and is connected with 6 ends of chip U10B with an end of capacitor C 8, the other end ground connection of capacitor C 8,5 ends of chip U10B are connected with 7 ends of chip U10B, one end of resistance R 9 is connected with 7 ends of chip U10B, the negative pole of the other end of resistance R 9 and stabilivolt Z1, after being connected, one end of the negative pole of Transient Voltage Suppressor T1 and capacitor C 9 connects the input end of multi-channel data acquisition card, the positive pole of stabilivolt Z1, the other end of the positive pole of Transient Voltage Suppressor T1 and capacitor C 9 altogether;

2) data processing and analysis module are made of industrial control computer and data analysis software, are carried out respectively exporting to the data presentation output module after Harmonics Calculation analysis, power calculation, voltage and current calculating, the power factor calculating through data processing and analysis module employing wavelet analysis method by the voltage and current value of data collecting module collected;

3) the data presentation output module is made of the software module of LCD and demonstration output, the input end of LCD is connected with the output terminal of data processing and analysis module, so that the data of data processing and analysis module output and the order of human-machine interface module are shown;

4) human-machine interface module is made of industrial control software and industry control peripheral apparatus, the output terminal of human-machine interface module is connected with the control interface of data processing and analysis module and the input end of data presentation output module so that with user's command transfer to data processing and analysis module and data presentation output module.

2, electric energy quality monitoring, recording and analyzing system according to claim 1, it is characterized in that: described four road voltage sensor V1, V2, V3, V4 are WB3V411S voltage isolation sensor, and the VGA of this sensor, VGB, VGC end are connected with S1～S4, S11～S14 end of analog switch MAX309 U7 and S11～S14 end of analog switch MAX309 U8.

3, electric energy quality monitoring, recording and analyzing system according to claim 1, it is characterized in that: current sensor I1～I16 of described at least ten six tunnel is a WB3I411S electric current isolation sensor, and the VGA of this sensor, VGB, VGC end are connected with NO1～NO8 end of analog switch MAX308 U1～U6.

4, electric energy quality monitoring, recording and analyzing system according to claim 1, it is characterized in that: described multi-channel data acquisition card, it has 12 A/D translation functions of gain, sampling rate is 100KS/s, the gain of each input channel can be programmed, integrated 4k sampling fifo buffer on the card, each the road signal after this capture card is proofreaied and correct correcting circuit are imported in data processing and the analysis module after this A/D conversion and are carried out record analysis.

5, electric energy quality monitoring, recording and analyzing system according to claim 1 is characterized in that: described industrial control computer is the one industrial computer.

6, electric energy quality monitoring, recording and analyzing system according to claim 1 is characterized in that: described industry control peripheral apparatus comprises CD-ROM drive, floppy drive, keyboard and mouse.

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