CN204103603U - A kind of distribution automation terminal - Google Patents

Abstract

A distribution network automation terminal, which includes a main controller, a digital signal processor, an AC analog acquisition unit, a switch input unit, a switch output unit, a communication unit, a memory unit, and a time synchronization unit; the AC analog acquisition unit is connected to The three-phase AC line of the power grid is used to collect the AC parameter value of the line; the AC analog quantity acquisition unit includes an A/D conversion module, and the A/D conversion module converts the analog quantity of the line AC parameter value collected by the AC analog quantity acquisition unit into a digital quantity, And output to the digital signal processor for processing; the main controller is connected to the digital signal processor to obtain the processed data; the main controller is connected to the control switch on the three-phase AC line through the digital input unit and the digital output unit to Collect switch status data and control switch status; the master controller communicates with the master station through the communication unit. The utility model has the advantages of high timing accuracy, reliable troubleshooting, strong self-adaptive ability, and can greatly reduce the misoperation ratio of the device.

Description

A distribution network automation terminal

technical field

The utility model relates to the technical field of distribution network automation, in particular to a distribution network automation terminal.

Background technique

Distribution network automation is the use of computer technology, automatic control technology, power technology, communication technology and new high-performance power distribution equipment and other technical means to conduct offline and online intelligent monitoring and management of the distribution network, so that the distribution network is always in a safe, Reliable, high-quality, cost-effective operation.

At present, the ratio of domestic distribution network automation technology is far lower than the international average level, and there is a lot of room for development. my country must first transform the topological structure of the distribution network to make it suitable for automation requirements, such as feeder segmentation, power distribution Network ring network, etc.; secondly, the section switch also needs to be replaced with a vacuum switch or permanent magnet switch capable of electric operation, and should have the necessary transformer; finally, the protection device in the switching station and distribution station should be able to provide A pair of signal contacts are used as an accident signal to distinguish between accident tripping and manual normal operation. However, there is still a big gap between my country's current distribution network and the above requirements. In order to realize distribution network automation, the transformation of traditional distribution network must be incorporated into the project. At present, domestic distribution network automation terminals generally have low sampling accuracy, adopt a single time synchronization method, and the time synchronization accuracy is low, which is not conducive to troubleshooting, poor self-adaptability, and does not support remote upgrade systems. Misoperation.

Contents of the invention

The purpose of the utility model is to provide a distribution network automation terminal, which has high timing accuracy, reliable troubleshooting, strong self-adaptive ability, and can support remote upgrade system, and can greatly reduce the misoperation rate of the device.

The technical solution adopted by the utility model is specifically: a distribution network automation terminal, including a main controller, a digital signal processor, an AC analog acquisition unit, a switching value input unit, a switching value output unit, a communication unit, and a main control unit respectively connected memory unit and timing unit of the device;

The AC analog quantity acquisition unit is connected to the three-phase AC line of the power grid to acquire the line AC parameter value; the AC analog quantity acquisition unit includes an A/D conversion module, and the A/D conversion module simulates the line AC parameter value collected by the AC analog quantity acquisition unit The quantity is converted into a digital quantity and output to the digital signal processor for processing; the main controller is connected to the digital signal processor to obtain the processed data;

The main controller is connected to the control switch on the three-phase AC line through the digital input unit and the digital output unit, so as to collect the switch status data of the control switch through the digital input unit, and to monitor the switch status of the control switch through the digital output unit. control;

The master controller communicates with the master station through the communication unit.

In the power system, general protection devices need to record the faults that occur. The recorded content includes the voltage and current values when the fault occurs, the status of the digital input, and the time when the fault occurred. The time of the protection device comes from the internal clock of the main controller or an external dedicated clock chip. This kind of hardware clock usually only counts to the second level, and the accuracy is low, which is not conducive to analyzing the cause of the fault. The timing function of the clock is realized by means of software. Although millisecond-level timing can be realized, the software clock cannot self-hold the time, that is, the software clock cannot continue to time when the protection device is powered off, and the time of the software clock cannot be reflected after the power is turned on again. For real time, a time synchronization operation must be performed every time the power is turned off, which is very inconvenient to use. In the distribution network automation terminal of the utility model, an independent hardware time synchronization unit is used to realize time synchronization. Regardless of whether the protection device is powered off, the time of the software clock is the current time, and the user does not need to reset the protection device after each power failure. On time. It can not only meet the precision requirement of millisecond level, but also has a high level of automatic time synchronization. The time synchronization unit adopts the existing time synchronization circuit or time synchronization module products, the time synchronization method can adopt the existing NTP, IRIG-B, RS232 serial port message and RS485 serial port message, etc., the controller can choose the best time signal , With accurate time, it is convenient to check the specific time when the fault occurred, which is conducive to accurate and efficient troubleshooting.

When the utility model is applied, the AC analog acquisition unit collects conventional analog quantities such as voltage, current, and power on the three-phase AC line. The acquisition circuit is an existing technology, and the A/D conversion module can use the existing A/D D converter or switching circuit. After the analog signals such as voltage and current are sampled and A/D converted, the digital signal processor performs filtering processing on these digital signals, and analyzes and calculates the effective signals obtained after filtering according to the conventional technology of the distribution network to obtain the required The effective value and phase of the voltage and current, active power, reactive power and other data are output to the main controller. The switch value input unit inputs the state signals required by the distribution network automation terminal, including the state of the switch and the energy storage state of the switch, into the main controller. The switching value input unit is an existing circuit, which is composed of circuit modules such as debounce filtering, signal shaping, photoelectric isolation, and decoding gating. The switching value output electric unit outputs the switch control signal output by the main controller, including data such as switch trip command and closing command.

The communication unit includes optical fiber Ethernet communication module, 3G communication module, power carrier communication module, GPRS communication module and EPON communication module. The integration of multiple communication modes makes the utility model more adaptable to the environment and more reliable in communication performance.

The memory unit includes SDRAM memory module and FLASH memory module. The main controller reads the startup code in the Flash memory module and stores it in SDRAM to run, which can realize the sharing of memory resources between FPGA and DSP, reduce the waste of memory resources, and improve the efficiency of data processing.

The switch value output unit includes a photoelectric isolation circuit and a relay contact circuit, and the main controller connects the relay contact circuit through the photoelectric isolation circuit to control the switching state of the control switch by controlling the closing or opening of the relay contact in the relay contact circuit . Both the photoelectric isolation circuit and the relay contact circuit are existing technologies. After the utility model combines the two, in the process of pulling and closing the power supply, when the power supply is at a certain critical voltage value, it can avoid possible damage caused by the disorder of the logic circuit. output malfunction.

The main controller of the utility model adopts the Xilinx FPGA chip whose model is EP1C3T100C8, which has a powerful logic calculation function, and is extended with an Ethernet debugging interface and various communication mode interfaces.

The digital signal processor of the utility model adopts floating-point digital signal processing model TMS320C6747, and its main frequency reaches 300MHz, which can realize functions such as data filtering and processing, sampling data integration and measurement and control algorithms.

The A/D conversion module of the utility model adopts a 14-bit ADC analog-to-digital converter whose model is AD7607 to realize multi-channel sampling. AD7607 has a built-in low-dropout voltage regulator, reference buffer, track and hold circuit, signal conditioning circuit, conversion clock, has oversampling function, and is equipped with high-speed parallel and serial interfaces. The sampling rate of each channel can reach 200ksps, and the input signal can be sampled synchronously. The conversion process and data acquisition are controlled by the CONVST signal and the internal oscillator, while retaining the relevant phase information of the signal on the input channel. The analog quantity acquisition function of the utility model is guaranteed.

The beneficial effect of the utility model is that: the setting of the independent time synchronization unit improves the time synchronization accuracy, making the power grid line troubleshooting more reliable. The integration of multiple communication modes enhances the adaptability of the utility model to various environments and can support remote system upgrades. The shared memory between the digital signal processor and the main control improves the efficiency of data processing, combined with the design of the switch output unit structure can greatly reduce the malfunction rate of the device.

Description of drawings

Shown in Fig. 1 is the structural representation of the utility model.

Detailed ways

Further description will be given below in conjunction with the accompanying drawings and specific embodiments.

1, the distribution network automation terminal of the utility model includes a main controller, a digital signal processor, an AC analog acquisition unit, a switching value input unit, a switching value output unit, a communication unit and a memory unit connected to the main controller respectively and timing unit;

The AC analog acquisition unit is connected to the three-phase AC line of the distribution network terminal grid to acquire the AC parameter value of the line; the AC analog acquisition unit includes an A/D conversion module, and the A/D conversion module converts the line AC acquired by the AC analog acquisition unit The parameter value is converted from analog to digital and output to the digital signal processor for processing; the main controller is connected to the digital signal processor to obtain the processed data;

The main controller is connected to the control switch on the three-phase AC line through the digital input unit and the digital output unit, so as to collect the switch status data of the control switch through the digital input unit, and to monitor the switch status of the control switch through the digital output unit. control;

The master controller communicates with the master station through the communication unit.

Example

In the embodiment shown in Fig. 1, the communication unit includes an optical fiber Ethernet communication module, a 3G communication module, a power carrier communication module, a GPRS communication module and an EPON communication module. The integration of multiple communication modes makes the utility model more adaptable to the environment and more reliable in communication performance.

The memory unit includes SDRAM memory module and FLASH memory module. The main controller reads the startup code in the Flash memory module and stores it in SDRAM to run, which can realize the sharing of memory resources between FPGA and DSP, reduce the waste of memory resources, and improve the efficiency of data processing.

The switch value output unit includes a photoelectric isolation circuit and a relay contact circuit, and the main controller connects the relay contact circuit through the photoelectric isolation circuit to control the switching state of the control switch by controlling the closing or opening of the relay contact in the relay contact circuit . Both the photoelectric isolation circuit and the relay contact circuit are existing technologies. After the utility model combines the two, in the process of pulling and closing the power supply, when the power supply is at a certain critical voltage value, it can avoid possible damage caused by the disorder of the logic circuit. output malfunction.

The main controller adopts the Xilinx FPGA chip model EP1C3T100C8, which has powerful logic calculation functions, and is extended with Ethernet debugging interface and various communication mode interfaces.

The digital signal processor adopts the floating-point digital signal processing model TMS320C6747, and its main frequency reaches 300MHz, which can realize functions such as data filtering and processing, sampling data integration and measurement and control algorithms.

The A/D conversion module adopts a 14-bit ADC analog-to-digital converter model AD7607 to realize multi-channel sampling. AD7607 has a built-in low-dropout voltage regulator, reference buffer, track and hold circuit, signal conditioning circuit, conversion clock, has oversampling function, and is equipped with high-speed parallel and serial interfaces. The sampling rate of each channel can reach 200ksps, and the input signal can be sampled synchronously. The conversion process and data acquisition are controlled by the CONVST signal and the internal oscillator, while retaining the relevant phase information of the signal on the input channel. The analog quantity acquisition function of the utility model is guaranteed.

In the power system, general protection devices need to record the faults that occur. The recorded content includes the voltage and current values when the fault occurs, the status of the digital input, and the time when the fault occurred. The time of the protection device comes from the internal clock of the main controller or an external dedicated clock chip. This kind of hardware clock usually only counts to the second level, and the accuracy is low, which is not conducive to analyzing the cause of the fault. The timing function of the clock is realized by means of software. Although millisecond-level timing can be realized, the software clock cannot self-hold the time, that is, the software clock cannot continue to time when the protection device is powered off, and the time of the software clock cannot be reflected after the power is turned on again. For real time, a time synchronization operation must be performed every time the power is turned off, which is very inconvenient to use. In the distribution network automation terminal of the utility model, an independent hardware time synchronization unit is used to realize time synchronization. Regardless of whether the protection device is powered off, the time of the software clock is the current time, and the user does not need to reset the protection device after each power failure. On time. It can not only meet the precision requirement of millisecond level, but also has a high level of automatic time synchronization. The time synchronization unit adopts the existing time synchronization circuit or time synchronization module products, the time synchronization method can adopt the existing NTP, IRIG-B, RS232 serial port message and RS485 serial port message, etc., and the controller can choose the best time signal , With accurate time, it is convenient to check the specific time when the fault occurred, which is conducive to accurate and efficient troubleshooting.

When the utility model is applied, the AC analog acquisition unit collects conventional analog quantities such as voltage, current, and power on the three-phase AC line. The acquisition circuit is an existing technology, and the A/D conversion module can use the existing A/D D converter or switching circuit. After the analog signals such as voltage and current are sampled and A/D converted, the digital signal processor performs filtering processing on these digital signals, and analyzes and calculates the effective signals obtained after filtering according to the conventional technology of the distribution network to obtain the required The effective value and phase of the voltage and current, active power, reactive power and other data are output to the main controller. The switch value input unit inputs the state signals required by the distribution network automation terminal, including the state of the switch and the energy storage state of the switch, into the main controller. The switching value input unit is an existing circuit, which is composed of circuit modules such as debounce filtering, signal shaping, photoelectric isolation, and decoding gating. The switching value output electric unit outputs the switch control signal output by the main controller, including data such as switch trip command and closing command.

In the utility model, the setting of the independent time-setting unit improves the time-setting precision, and makes the troubleshooting of the grid line more reliable. The integration of multiple communication modes enhances the adaptability of the utility model to various environments and can support remote system upgrades. The shared memory between the digital signal processor and the main control improves the efficiency of data processing, combined with the design of the switch output unit structure can greatly reduce the malfunction rate of the device.

Claims (7)

1. a distribution automation terminal, it is characterized in that, comprise master controller, digital signal processor, ac analog collecting unit, On-off signal unit, switch amount output unit, communication unit and connect respectively master controller memory cell and pair time unit;

Ac analog collecting unit connects electrical network three-phase AC line, to gather circuit alternating-current parameter value; Ac analog collecting unit comprises A/D modular converter, and the circuit alternating-current parameter value analog quantity that ac analog collecting unit collects by A/D modular converter is converted to digital quantity, and exports digital signal processor to and process; Master controller linking number word signal processor is to obtain data after treatment;

Master controller is connected the control switch on three-phase AC line with switch amount output unit by On-off signal unit, to be gathered the on off state data of control switch by On-off signal unit, and controlled by the on off state of switch amount output unit to control switch;

Master controller to be connected with main website by communication unit and to communicate.

2. distribution automation terminal according to claim 1, is characterized in that, communication unit comprises fiber optic Ethernet communication module, 3G communication module, power line carrier, PLC module, GPRS communication module and EPON communication module.

3. distribution automation terminal according to claim 1, is characterized in that, memory cell comprises sdram memory module and FLASH memory unit module.

4. distribution automation terminal according to claim 1, it is characterized in that, switch amount output unit comprises photoelectric isolating circuit and relay contact circuit, master controller connects relay contact circuit by photoelectric isolating circuit, is controlled the on off state of control switch by the closed of control relay contact circuit repeat circuit contact or disconnection.

5. the distribution automation terminal according to any one of Claims 1-4, is characterized in that, master controller employing model is the match SEL fpga chip of EP1C3T100C8.

6. the distribution automation terminal according to any one of Claims 1-4, is characterized in that, digital signal processor adopts model to be the floating-point signal processor of TMS320C6747.

7. the distribution automation terminal according to any one of Claims 1-4, is characterized in that, A/D modular converter employing model is 14 ADC analog to digital converters of AD7607.