CN201327515Y - Distributed electrical energy quality online monitoring instrument based on dual-CPU - Google Patents

Abstract

The utility model provides a distributed power quality online monitor based on dual CPUs, including a signal conditioning circuit module, an AD sampling circuit module, a DSP data processing module, an ARM upper management machine module, a power line carrier communication module and a liquid crystal display module; AD The sampling circuit realizes the synchronous sampling of the 6-channel power signal; the high-speed data transmission between the DSP module and the ARM module is realized by using the dedicated HPI host port; the ARM module uses WinCE as the operating system and software development platform; the power line carrier communication module is used to realize the communication with Data communication of remote monitoring center. This device can realize real-time and accurate power quality measurement and analysis, and has a friendly and convenient management and interaction interface, which is suitable for single-point power quality monitoring or distributed power quality online monitoring system.

Description

Distributed Power Quality Online Monitor Based on Dual CPU

technical field

The utility model relates to a power quality monitoring technology, in particular to a design technology of a distributed power quality online monitor based on DSP and ARM double CPUs.

Background technique

In the field of design and development of power quality monitors, there are mainly two types of design schemes: one is the design scheme based on the embedded platform, including single-chip microcomputer, DSP and ARM; the other is the design scheme based on the industrial computer. The monitoring instrument based on the single-chip microcomputer has defects in many aspects such as fast data analysis and intelligent management software; although the monitoring instrument based on DSP has fast data processing capability, it is difficult to develop management software and the efficiency is low; the monitoring instrument based on ARM can Running an embedded operating system, it is good at the development and design of upper-level management software, but lacks data signal processing capabilities; monitors based on industrial computers use hard disks to store data, which has low reliability, is large in size and difficult to carry, and is expensive.

In order to overcome the above-mentioned shortcomings of the prior art, Chinese Patent No. 200720052102.3 discloses a portable power quality monitoring analyzer based on dual CPU mode, including a data collector ADS8364, a synchronous sampling phase-locked loop circuit, a digital signal processor DSP module, ARM module and TFT liquid crystal display touch screen;

The described data collector ADS8364 that provides 6 sampling channels to realize the collection of each electric energy index is electrically connected with the synchronous sampling phase-locked loop circuit, and the described data collector ADS8364 is electrically connected with the digital processor DSP module through a data line;

The digital processor DSP module is connected with the ARM module through the serial communication interface SCI-A;

Realize the analysis and display of DSP calculation results. The ARM module is electrically connected with the TFT liquid crystal display touch screen. The ARM module transmits the data received from the digital signal processor DSP to the TFT liquid crystal display touch screen for display. The TFT liquid crystal display touch screen is displayed through the mouse Or hand touch operation to realize the viewing of various electric energy indicators.

However, since most of its dual CPUs are connected by serial ports, it is impossible to realize high-speed transmission of large amounts of data between chips, and a large amount of real-time power quality data and calculation result data collected by DSP cannot be transmitted to ARM in real time;

Moreover, only the Ethernet communication interface is provided for remote communication. When it is used to build a distributed online power quality monitoring system, the cost of building a communication network is high due to the large number and wide distribution of monitors arranged;

Furthermore, ARM machines generally use μCOS/II or Lunix as the development platform of the operating system management software. The former is too simple to implement complex functions, and the latter is not easy to operate and prolongs the system development cycle.

Contents of the invention

The purpose of this utility model is to provide a kind of on-site or distributed online networking monitoring for monitoring points, which can provide voltage, current, frequency, power factor and active power in real time. , reactive power and other basic power parameters, can accurately measure, calculate, analyze, count and alarm power quality indicators such as harmonics, three-phase unbalance, voltage fluctuation and flicker of the power system, and have event records, faults With complex functions such as wave recording and remote communication, it can transmit DSP data to ARM in real time. It is a distributed power quality monitor based on DSP and ARM dual CPU mode with low communication network cost and friendly operating system.

Distributed online power quality monitor based on dual CPU, including data acquisition module, DSP digital signal processing module, ARM module, TFT liquid crystal display touch screen;

The data acquisition module has 6 sampling channels, the data acquisition module is electrically connected to the digital processing module through the data line, the signal collected by the data acquisition module is transmitted to the digital processing module through the data line, and the The control command issued by the digital processing module is transmitted to the data acquisition module through the control line;

The ARM module that realizes the analysis and display of the digital processing calculation results is electrically connected with the TFT liquid crystal display touch screen. The ARM module transmits the data received from the digital processing module to the TFT liquid crystal display touch screen for display. Or hand touch operation to realize the viewing of various electric energy indicators;

It is characterized in that: the digital processing module is connected with the ARM module through a dedicated host parallel interface (HPI) to form a master-slave system, and the ARM module can access the digital processing module through the HPI interface All the storage space and the peripherals mapped by the address space, and then control the digital processing module to realize data exchange.

Further, the input signal of the data acquisition module is an output signal of a signal conditioning module, and the signal conditioning module includes a voltage and current sensor for secondary conversion of the voltage and current signals output by the power transformer, which can realize 6 A filter unit for low-pass filtering of the channel signal, and a voltage conversion unit that can convert the electrical signal into a level signal that matches the input of the data acquisition module, and the voltage conversion unit can convert the bipolar voltage signal into an amplitude A unipolar signal ranging from 0 to 5V; the three-phase voltage and current signals on the power line pass through voltage and current sensors, a filter unit, and a voltage conversion unit in sequence, and the output signal of the voltage conversion unit is the output signal of the signal conditioning module .

Further, the ARM module is connected to the power line carrier communication module through an asynchronous serial interface RS-232, and the power line carrier communication module can use the existing power line as a communication channel to realize the data transmission between the monitor and the remote monitoring center. Communication IT800D power line carrier communication dedicated chip.

Further, described ARM module adopts WinCE as operating system and software development platform, and described ARM module has the SD card that can preserve a large amount of sampling data and analysis processing result, and the NandFlash that is used to deposit main program.

Described HPI (Host-Post Interface) interface is a parallel communication port that DSP is connected with main frame, is to build master-slave type system, realizes the important interface of main frame and slave machine communication. Through the HPI, the host can access all the storage space in the DSP and the peripherals mapped by the address space, and then control the DSP to realize data exchange.

The S3C2410X ARM microprocessor is an ARM920T-based microprocessor with low power consumption, high integration and high cost performance, and is widely used in the field of embedded control. Using WinCE as the operating system and software development platform, the interface is beautiful and operable.

Compared with the prior art, the utility model has the following advantages:

(1) The dual-CPU embedded system is used as the hardware platform, and the TMS320C6713 floating-point processor is adopted. This is a high-speed floating-point processor launched by TI. Its maximum main frequency can reach 225MHz, which can cope with a large amount of data of various power quality indicators And complex algorithms, which ensure the real-time and accuracy of data processing, are suitable for the high-performance requirements of distributed online power quality monitoring systems.

(2) The digital processing module uses a dedicated HPI host parallel interface to realize the connection with the ARM module. The hardware interface connection of the HPI host parallel interface is very simple and easy to implement. Real-time transmission of large amounts of data is required, and it works in the master/slave mode. When reading and writing data, DSP is only equivalent to the external memory of ARM without affecting its data processing.

(3) The power line carrier communication module is used to realize data communication with the remote monitoring center, and the existing power line can be directly used as the communication carrier without additional laying of communication lines, which saves a lot of costs.

(4) S3C2410X ARM uses WinCE as the operating system and software development platform, the monitor interface is beautiful, and the operability is strong; the voltage and current waveform data, power quality parameters, and various indicators are stored in the large-capacity SD card of the ARM module by using an embedded database The memory card is convenient for future investigation and review; the TFT liquid crystal display touch screen enhances human-computer interaction, making it convenient for users to view various power quality parameters.

(5) Small in size, easy to carry, and low in price, it can be used not only for single-node power quality monitoring, but also for distributed power quality online monitoring systems.

Description of drawings

Fig. 1 is the structural diagram of the distributed electric energy quality on-line monitor based on double CPU of the present utility model;

Fig. 2 is the structural diagram of the signal conditioning circuit module of the power quality on-line monitor of the present invention;

Fig. 3 is the HPI interface connection diagram between TMS320C6713DSP and S3C2410XARM in the power quality on-line monitor of the present utility model;

Fig. 4 is the HPI interface reading timing diagram between TMS320C6713DSP and S3C2410XARM in the distributed power quality monitor of the present utility model;

Fig. 5 is the structural diagram of the power line carrier communication module of the power quality on-line monitor of the present invention;

Fig. 6 is the DSP main program flowchart of the electric energy quality on-line monitor of the present utility model;

Fig. 7 is the ARM main program flow chart of the electric energy quality on-line monitor of the present invention.

Detailed ways

With reference to accompanying drawing, further illustrate the utility model:

Distributed online power quality monitor based on dual CPU, including data acquisition module, digital signal processing module, ARM module and TFT liquid crystal display touch screen;

The data acquisition module has 6 sampling channels, the data acquisition module is electrically connected to the digital processing module through the data line, the signal collected by the data acquisition module is transmitted to the digital processing module through the data line, and the The control command issued by the digital processing module is transmitted to the data acquisition module through the control line;

The ARM module that realizes the analysis and display of the digital processing calculation results is electrically connected with the TFT liquid crystal display touch screen. The ARM module transmits the data received from the digital processing module to the TFT liquid crystal display touch screen for display. Or hand touch operation to realize the viewing of various electric energy indicators;

The digital processing module is connected with the ARM module through a dedicated host parallel interface (HPI) to form a master-slave system, and the ARM module can access all storage of the digital processing module through the HPI interface. The peripherals mapped to the space and address space, and then control the digital processing module to realize data exchange.

The input signal of the data acquisition module is an output signal of a signal conditioning module, and the signal conditioning module includes a Hall-type voltage and current sensor that performs secondary transformation on the voltage and current signals output by the power transformer, which can realize The filter integrated chip MAX274 for low-pass filtering of the 6-channel signal, and the voltage conversion unit that can convert the electrical signal into a level signal that matches the input of the data acquisition module.

The ARM module is connected to the power line carrier communication module through an asynchronous serial interface RS-232, and the power line carrier communication module adopts the existing power line as a communication channel to realize the data communication between the monitor and the remote monitoring center IT800D low-voltage power line carrier communication dedicated chip.

Described ARM module adopts WinCE as operating system and software development platform, and described ARM module has the SD card that can save a large amount of sampling data and analysis processing result, and the NandFlash that is used to deposit main program.

The implementation of each module in the data acquisition subsystem is as follows:

As shown in Figure 2, the signal conditioning module includes a Hall-type voltage and current sensor, a filter unit, and a voltage conversion unit. Among them, the Hall-type voltage and current sensors have the advantages of high precision, good linearity, fast response, and small size; the filter unit adopts the integrated chip MAX274, which has the advantages of simple design and good performance; the voltage conversion is to make the original bipolar The signal is converted into a unipolar signal with an amplitude range of 0-5V to meet the input signal requirements of the AD converter; the conditioned 6-way signals are sent to the data acquisition module at the same time.

The data acquisition module uses the ADS8364AD converter, which is a high-speed, low-power consumption, six-channel completely independent 16-bit successive approximation analog-to-digital converter, which solves the problem of synchronous sampling of three-phase voltage and three-phase current signals; due to the ADS8364 chip It is a +5V device, while TMS320C6713DSP is a +3.3V device. When designing hardware connection, a level conversion chip is used to isolate the signal line and data line; the specific logic control relationship between DSP and ADS8364 is completed by the FPGA chip XC3S400 to ensure correct control AD performs synchronous sampling on six channels and meets the highest sampling rate of ADS8364.

The digital processing module uses TMS320C6713DSP to realize data sampling, temporary storage, calculation and analysis. Use software to realize frequency tracking, and determine the sampling rate of the next cycle based on the system frequency calculated by the current sampling, so as to realize real-time adjustment of the sampling period and improve the accuracy of sampling; the calculation content of power quality indicators carried out by DSP includes three-phase voltage and current RMS value, system frequency, power factor, various power, voltage deviation, total harmonic distortion rate and each harmonic content, voltage fluctuation and flicker, three-phase unbalance rate, etc.

As shown in Figure 3, the DSP is connected to the ARM module through a dedicated HPI host parallel interface. The hardware connection of the HPI interface is simple. Through it, the ARM can directly access the internal and external storage space of the DSP, and can also access the memory-mapped peripherals. When the DSP is ready for data, it sends an interrupt to ARM through HINT, which responds to the interrupt and reads data from the DSP memory. When accessing, ARM first initializes the HPI control (HPIC) register, then initializes the address (HPIA) register, and then writes the data to or from the HPI data (HPID) register. The HPI read sequence is shown in Figure 4. case1 means that the prefetch value of the previous auto-increment address mode access has not been completed, then HRDY becomes high after the falling edge of HCS, and case2 means that there is no valid data in the HPID register, then HRDY is in HCSTROBE becomes high level after the falling edge, because the data channel of the embedded CPU is 32 bits, and the data line of HPI is only 16 bits, so a word needs to be transmitted twice, HHWIL is 0 means the first half word is transmitted, It is 1 to indicate the transmission of the second half word, HCNTL[1~0] indicates which internal HPI register is being accessed, and the state of these two pins selects to access the HPI address register, HPI data register or HPI control register.

The ARM module uses Samsung's S3C2410X ARM, uses WinCE as the operating system and software development platform, and is responsible for saving, counting, analyzing and processing the data transmitted by the DSP; it is connected to the TFT liquid crystal display touch screen module for display, and connected to the SD card to realize big data It is connected to the power line carrier communication module through the RS-232 interface to realize system monitoring and management, graphic display, event recording, historical data storage and other functions.

As shown in Figure 5, the IT800D used in the power line carrier communication module is a dedicated carrier communication Modem chip developed for the low-voltage power line carrier communication market; all operations between IT800D and ARM, including parameter setting, sending data, receiving data, etc. Realized through RS-232 serial port, no need to use external interrupt, no need to use bit operation, which greatly simplifies the user program design process and saves user CPU resources. This module can directly use the power line to build a distributed power quality online monitoring system without arranging additional communication channels, and realize the remote communication function of the monitor; therefore, the remote monitoring center can analyze and count changes in the power quality in the system, and provide The historical trend of power quality changes is used to evaluate the power quality level of the system, discover equipment problems, and evaluate the performance of installed power adjustment equipment.

The working principle of the distributed power quality online monitor based on dual CPUs is as follows:

(1) The 6-channel signal of the three-phase voltage and current signal on the power line is converted into a unipolar signal with an amplitude of 0-5V by the signal conditioning circuit and sent to the digital acquisition module. Under the logic control of the FPGA, the 6-channel signal is realized. Synchronous sampling; use software to realize frequency tracking, and determine the sampling rate of the next cycle based on the system frequency calculated by the current sampling, so as to realize real-time adjustment of the sampling cycle; the digital signal after A/D conversion is sent to the digital processing module and saved;

(2) described digital processing module reads AD sampling data in real time and carries out the calculation of each electric energy index, and calculation result is temporarily stored in SDRAM, sends interrupt notification ARM module after waiting time arrives, and ARM module responds to interrupt and reads by HPI mainframe parallel interface Pick;

(3) The ARM module counts, analyzes and processes the data received from the DSP through the HPI interface, and stores the power quality parameters, various indicators and waveform data to the external SD card through the WinCE database; various data are as required Send it to the TFT liquid crystal display touch screen for display, and realize the viewing of various electric energy indicators and related data tables and graphics through mouse or hand touch operations;

(4) The power line carrier communication module realizes the connection with the ARM module through the RS-232 interface, and transmits the data to be sent from the ARM to the peripheral interface circuit of IT800D, performs framing, adds CRC check, and sends it to the physical layer, After processing, the on-chip DA converter converts it into an analog signal, sends it to the output filter and line driver, and sends it to the power line through the coupling coil. The remote communication module performs corresponding decoupling and receives the data, so as to realize the data exchange between the monitor and the remote monitoring center. communication.

The main program flow of the digital processing module is shown in Figure 6. The implementation process of its frequency tracking is: first, TMS320C6713DSP power-on reset enters the initialization process, the initialization process includes EMIF initialization, PLL initialization, interrupt control register initialization and initial value for timer 1, then open the global interrupt and start timer 1 timing, Timer 1 generates an int15 interrupt after timing to the specified value. At this time, the DSP enters the interrupt service program. In the interrupt service program, the DSP generates a control signal to make the AD circuit perform a sampling conversion, and then the DSP reads the converted data of the AD circuit and records the sampling. frequency. The DSP works according to this law, and takes 128 points for each cycle. When the DSP judges that the number of samples is 128, it analyzes and processes the 128 sets of sampled data. First, it calculates the frequency of the power system and uses this as a basis to reset the timer count. Period, so as to realize the frequency tracking of the signal, and finally calculate other power quality indicators, including three-phase voltage and current effective value, power factor, various power, voltage deviation, total harmonic distortion rate and each harmonic content, Voltage fluctuation, flicker, and three-phase unbalance rate, so the DSP power quality index calculation program must be efficient, so that the analysis and calculation of the previous cycle sampling data can be completed within the next cycle, that is, 128 sampling intervals.

ARM main program flow chart shown in Figure 7. First, system initialization is performed on the ARM module, and then waits for the DSP to send an interrupt. After receiving the interrupt signal, the data is read from the digital processing module through the parallel interface of the HPI host, and then the ARM S3C2410X displays the voltage and current waveforms on the TFT LCD screen, and at the same time It also performs statistical analysis on some data read from the DSP, and compares the statistical analysis results with the theoretical values. If it exceeds the normal range, ARM will issue a warning, and the statistical analysis results will be stored in the WinCE database and displayed on the TFT LCD touch screen. . The user only needs to click on the power quality index item that needs to be viewed, and ARM will completely display the power quality index.

Through the above method, the design of a distributed power quality online monitor based on dual CPUs can be realized, which has both the high performance of DSP in data processing and the superiority of ARM in the development and design of upper management software, and can be directly The original power line is used as the channel to realize the construction of the distributed on-line monitoring system.

The content described in the embodiments of this specification is only an enumeration of the realization forms of the utility model concept, and the protection scope of the utility model should not be regarded as being limited to the specific forms stated in the embodiments, and the protection scope of the utility model also extends to Equivalent technical means that those skilled in the art can think of according to the concept of the utility model.

Claims (4)

1,, comprises data acquisition module, digital signal processing module, ARM module and TFT liquid crystal display touch-screen based on the distributed online electric energy quality monitor of two CPU;

Described data acquisition module has 6 road sampling channels, described data acquisition module is connected with digital signal processing module by data line, described data collecting module collected to signal be sent to digital signal processing module by data line, the control command that described digital signal processing module sends is sent in the data acquisition module by data line;

Realization is electrically connected with TFT liquid crystal display touch-screen the ARM module of digital processing calculated result analysis and demonstration, the ARM module sends the data that receive to TFT liquid crystal display touch-screen and is shown from digital signal processing module, described TFT liquid crystal display touch-screen is realized checking each power index by mouse or hand touch operation;

It is characterized in that: described digital signal processing module is connected to form master-slave system by private host parallel interface (HPI) and described ARM module, described ARM module can be visited whole peripheral hardware that storage space and address space shone upon of described digital signal processing module by described HPI interface, and then the control figure processing module, realize exchanges data.

2, monitor as claimed in claim 1, it is characterized in that: further, the input signal of described data acquisition module is the output signal of a signal condition module, described signal condition module comprises that the voltage and current signal to electric power mutual-inductor output carries out the voltage of quadratic transformation, current sensor, can realize the filter unit of the low-pass filtering of 6 road signals, and the voltage transformation module that electric signal can be converted into the level signal that is complementary with the data acquisition module input, described voltage transformation module can be transformed to ambipolar voltage signal the one pole type signal that amplitude range is 0～5V; Three-phase voltage on the line of electric force, current signal be successively through superpotential, current sensor, filter unit, and voltage transformation module, the output signal of described voltage transformation module is the output signal of signal condition module.

3, monitor as claimed in claim 2, it is characterized in that: described ARM module is connected with Power Line Carrier Communication Module by an Asynchronous Serial Interface RS-232, described Power Line Carrier Communication Module adopts and can realize the IT800D low voltage power line carrier communication special chip of the data communication at monitor and remote monitoring center with the existing power line as communication port.

4, monitor as claimed in claim 3, it is characterized in that: described ARM module adopts WinCE as operating system and Software Development Platform, described ARM module has the SD card that can preserve a large amount of sampled datas and analysis processing result, and the NandFlash that is used for depositing master routine.

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