CN205720433U - A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network - Google Patents

Abstract

An online distribution network harmonic monitoring device based on a wireless sensor network, comprising a current transformer and a voltage transformer, the current transformer and the voltage transformer are respectively connected to a signal conditioning module, and the signal conditioning module is connected to a harmonic analysis module, The harmonic analysis module is connected to the wireless transmitting module, the wireless transmitting module and the wireless receiving module are connected through a wireless network, the wireless receiving module is connected to the control module, and the control module is connected to the display module and the GPS timing module. The utility model is an on-line monitoring device for harmonics of a distribution network based on a wireless sensor network, which has the advantages of accurate data detection, convenient use, real-time detection, simple structure and low cost; and can be combined with a GPS timing module to monitor the harmonics on-line.

Description

An on-line monitoring device for distribution network harmonics based on wireless sensor network

technical field

The utility model relates to the field of power systems, in particular to an on-line harmonic monitoring device for a distribution network based on a wireless sensor network.

Background technique

With the continuous expansion of the scale of the power grid, the load structure of the power grid has undergone great changes, and a variety of non-linear, asymmetrical, impactful and unbalanced electrical equipment has been used in large quantities, causing a large number of harmonic interference in the power grid. The power quality in the grid will cause serious pollution, the power factor will deteriorate, and it will disturb other equipment and devices, which will seriously threaten the power quality of the power grid and the safe operation of power equipment. When the impact power load is put into the distribution network, the voltage of the distribution network will fluctuate, which seriously interferes with the normal operation of fluctuation-sensitive loads in the power grid, such as lighting, computers, and precision electronic instruments. Once a power quality problem occurs, it will cause equipment failure in the slightest, and damage to the entire system in the worst case. The resulting losses are immeasurable. Therefore, real-time and effective monitoring of distribution network harmonics is of great significance to ensure the safe and stable operation of the power system. Due to the extensive distribution of distribution lines and the universality of harmonic sources, most of the existing distribution network harmonic monitoring systems use offline methods to monitor data, and offline methods can only obtain partial harmonic data during the test period, although there are certain references , guiding significance, but it is impossible to obtain real and detailed real-time harmonic data of distribution lines for a long time.

Contents of the invention

For the current distribution network harmonic monitoring devices, most of them use offline methods to monitor data, which can only obtain one-sided harmonic data during the test period, and cannot obtain real and detailed real-time harmonic data of distribution lines for a long time, and cannot accurately locate harmonics And other issues. The utility model provides an on-line monitoring device for harmonics of a distribution network based on a wireless sensor network, which has the advantages of accurate data detection, convenient use, real-time detection, simple structure and low cost; and can be combined with a GPS timing module for online monitoring of harmonics.

The technical scheme adopted in the utility model is:

An online distribution network harmonic monitoring device based on a wireless sensor network, comprising a current transformer and a voltage transformer, the current transformer and the voltage transformer are respectively connected to a signal conditioning module, and the signal conditioning module is connected to a harmonic analysis module, The harmonic analysis module is connected to the wireless transmitting module, the wireless transmitting module and the wireless receiving module are connected through a wireless network, the wireless receiving module is connected to the control module, and the control module is connected to the display module and the GPS timing module.

The current transformer and voltage transformer are used to collect the current and voltage information of the power line, and output to the harmonic analysis module through the signal conditioning module.

The harmonic analysis module includes a DSP digital signal processor and an A/D conversion module, and the DSP digital signal processor is used to read the A/D conversion result, and perform analysis, calculation and processing of relevant harmonic parameters; the processing result is transmitted through the wireless The transmitting module and the wireless receiving module are sent to the control module, and the control module is used for data processing and storage; the display module is used to realize real-time online monitoring of the harmonic parameters of the distribution network;

The GPS timing module is used for the A/D conversion result read by the DSP digital signal processor to realize synchronous acquisition by the GPS timing, and the GPS timing module displays the collected data on the control module through the timing channel of the remote communication module . Realize precise synchronization of clock signal and data acquisition, improve accuracy and clock synchronization accuracy of the entire monitoring system.

The DSP digital signal processor is a TMS320F2812 type DSP chip. The processor is a high-performance, low-power, highly-integrated microprocessor launched by Samsung Semiconductor Corporation, which greatly simplifies the design of peripheral circuits. The highest operating frequency can reach 150MHz, which provides sufficient conditions for real-time control, reading conversion data and completing complex algorithms in a short period of time.

The wireless transmitting module and the wireless receiving module adopt nRF2401 wireless transceiver module.

The control module is composed of an external memory, an ARM chip processor, and peripheral circuits, wherein the ARM chip processor adopts a S3C2440B microprocessor.

The utility model provides a distribution network harmonic online monitoring device based on a wireless sensor network. Compared with the existing known technology, the utility model has the following beneficial effects:

1) Compared with the traditional offline method monitoring data, offline monitoring can only obtain one-sided harmonic data during the test period, and cannot obtain real and detailed real-time harmonic data of distribution lines for a long time, and cannot accurately locate harmonics And other issues. The use of nRF2401 wireless transceiver module can realize wireless data transmission between DSP and ARM chip, and can achieve online monitoring. The system is compact in structure, easy to implement, reliable in performance, and capable of real-time on-line monitoring of power distribution harmonics, which has high application and promotion value.

2) Install the GPS timing module to realize the synchronous collection of control signals for the entire harmonic monitoring system and improve the accuracy of time synchronization of the system's online monitoring.

Description of drawings

Fig. 1 is the connection diagram of the utility model.

detailed description

As shown in Figure 1, a distribution network harmonic online monitoring device based on a wireless sensor network includes a current transformer and a voltage transformer. The harmonic analysis module is connected, the harmonic analysis module is connected to the wireless transmitting module, the wireless transmitting module and the wireless receiving module are connected through a wireless network, the wireless receiving module is connected to the control module, and the control module is connected to the display module and the GPS timing module.

Both the current transformer and the voltage transformer are connected to the distribution network, and the output terminals of the voltage transformer and the current transformer are connected to the signal conditioning module. The voltage transformer and the current transformer connect the measured high voltage and large The current signal is converted into the small signal required by the A/D conversion module, the voltage on the secondary side of the voltage transformer becomes 100V, and the secondary side of the current transformer becomes 5A, and then the high-frequency interference in the signal is filtered out by a low-pass filter After that, it is sent to the A/D conversion module for analog-to-digital conversion. The A/D conversion module selects the high-performance analog-to-digital converter ADS8364, uses the 6 channels of ADS8364 to sample the three-phase AC voltage and current synchronously, and the 16-bit digital quantity ensures the sampling accuracy.

In the DSP digital signal processor, the DSP reads the A/D conversion result and performs analysis, calculation and processing of relevant harmonic parameters. The DSP digital signal processor adopts the TMS320F2812 chip, and the maximum operating frequency can reach 150MHz, which provides sufficient conditions for real-time control and completing complex algorithms in a short period of time. The DSP responds to the instructions of the ARM control module and controls the ADS8364 to complete the A/D conversion. , read the converted data, perform fast Fourier transform (FFT) and calculation of related parameters, process the digital signal obtained after the front-end A/D conversion, and use the fast Fourier algorithm (FFT) to measure the three-phase voltage UA, UB , UC sub-harmonic voltage, sub-voltage harmonic content and total voltage harmonic content; can also measure three-phase current IA, IB, IC sub-harmonic current, sub-current harmonic content and total Current harmonic content.

The wireless sensor network adopts nRF2401 wireless transmission module, and selects nRF2401, a new single-chip radio frequency transceiver device, which works in the 2.4GHz-2.5 GHz ISM frequency band, and the output power and communication channel can be configured through programming. At the same time, nRF2401 has low power consumption. When transmitting at -6dBm power, the operating current is only 9mA, and when receiving signals, the operating current is only 12.3mA, which is especially suitable for single-chip applications. Control the nRF2401 to work in the receiving mode, and start collecting and sending data until the command to start collecting is received. After receiving the data packet sent by the DSP signal processor, control the nRF2401 to work in the transmission mode, read it out and send instructions downward, the nRF2401 wireless transmission module transmits the collected power signal for the harmonic analysis module DSP, once connected After receiving the instruction, control the nRF2401 to work in the receiving mode, receive the data packet, realize the connection with the control module, and finally transmit the data to the control module.

The control module is composed of an external memory, an ARM chip processor and peripheral circuits. The ARM chip uses the S3C2440B microprocessor, which is a high-performance, low-power, and highly integrated microprocessor launched by Samsung Semiconductor Corporation. It has rich hardware resources and greatly simplifies the design of peripheral circuits. At the same time, a 4.3-inch TFT LCD screen is used as a display, and a 2GSD card is used to store harmonic parameters.

The GPS timing module includes a GPS module and a remote communication module. The GPS timing module accepts the data reflected by the DSP and ARM chip to collect GPS data and send the current status, etc. The data acquisition module obtains the current GPS information through the GPS module connected to the serial port. The model of GPS module is BR-355, and the remote communication module adopts UT4432 wireless module. The data communication of the GPS module uses the serial port for communication, and the GPS module sends out a PPS second pulse and a series of positioning, clock and other information every second. The GPS module receives satellite signals, realizes the time synchronization monitoring of the entire system through the timing channel (RS232), and reads the A/D conversion results through the DSP digital signal processor of harmonic analysis to realize synchronous acquisition by GPS timing, and the GPS timing system will collect The data of the remote communication module is displayed on the control module equipped with the ARM chip through the timing channel of the remote communication module, so as to realize the precise synchronization of the system clock signal and data acquisition.

Claims (7)

1. a Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, including current transformer, voltage transformer, It is characterized in that: described current transformer, voltage transformer connect Signal-regulated kinase respectively, Signal-regulated kinase connects harmonic wave Analyzing module, frequency analysis module connects wireless transmitter module, and wireless transmitter module and wireless receiving module pass through wireless network Connecting, wireless receiving module link control module, control module connects display module, GPS time service module.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: described current transformer, voltage transformer are for gathering the electric current of power circuit, information of voltage, and pass through signal condition mould Block exports to frequency analysis module；Described frequency analysis module includes DSP, A/D modular converter, DSP number Word signal processor is used for reading A/D transformation result, and carries out the analysis of associated harmonic parameter, computing and process；Result Delivering to control module by wireless transmitter module, wireless receiving module, control module is used for carrying out data and processes and storage；Display Module is for realizing the real time on-line monitoring of Distribution Network Harmonics parameter；Described GPS time service module, for by DSP digital signal The A/D transformation result that reason device reads, is realized synchronous acquisition by GPS time service, and the data that GPS time service module will gather, by remotely The time service passage of communication module shows in control module.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: described DSP is TMS320F2812 type dsp chip.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: described wireless transmitter module, wireless receiving module use nRF2401 type wireless receiving and dispatching pattern block.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: described control module is made up of external memory storage, ARM chip processor and peripheral circuit, wherein ARM chip processor Use S3C2440B microprocessor.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: described GPS time service module includes GPS module, remote communication module, and GPS time service module accepts by anti-on DSP Yu ARM chip The data answered, to gather gps data, send current state；Obtain current GPS by the GPS module being connected with serial ports to believe Breath.

A kind of Distribution Network Harmonics on-Line Monitor Device based on radio sensing network, its feature exists In: GPS module model is BR-355, and remote communication module uses UT4432 wireless module.