Application of the hottest dual high embedded indu

2022-08-22
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The application of dual high embedded industrial computer platform in power system

ensuring high reliability, improving operation performance, flexible application and easy expansion are the key to the microcomputer monitoring design of power system. In the traditional design, two kinds of platforms are mainly used: special structure platform and general industrial control platform. The former mainly uses 8051, 80C196 and other single-chip computers as the main CPU, RS-485, can and LonWorks as the data communication network. Most of them use single board or customized small bus, which has strong pertinence, compact system structure, high overall performance and reliability, but there are shortcomings in versatility, scalability and system upgrading. The latter usually adopts STD bus, industrial PC, PC104 and other buses that are widely used at present. The structure has good versatility and scalability, and it is also easy to upgrade the system. However, due to the use of general structure, the system has more redundancy, and the "golden finger" of the bus, too many plug-ins and flat cables also reduce the reliability of the system

1 modular plug-in structure

from the idea of "open system structure and combination design method", the system design still adopts the modular plug-in structure, and the bus structure connection between templates is a better method, which is conducive to the expansion and upgrading of the system

1.1 plug-in structure

the connection between the signal line and the i/o template in the power system generally adopts the winding method, such as the European style 48 core winding connector; At the same time, the i/o interface is required to be led out from the back end of the template. The template of the front pulsation fatigue testing machine is mainly man-machine interface, such as LCD interface and keypad interface. It is difficult to meet this requirement for industrial computers using general STD or PC bus structure. Therefore, the design of the plug-in structure adopts the standard VME double height size, the chassis is 6U high, the upper part is the i/o bus, which directly gives the interface of the winding mode, and the lower part is the three buses of data, address and control (see Figure 1)

1.2 bus

the system with plug-in structure widely uses standard parallel backplane bus. It can support high-speed data transmission and processing with simple hardware, and make the whole system have high compatibility and flexible configuration

adopt 96 core European pinhole structure. Practice has proved that the pin mode is more reliable than the "golden finger" mode. Especially in the harsh environment with high reliability requirements, the pin is wrapped in the socket and isolated from the external environment, which can better resist the impact of the harsh environment

signals are defined by standard Isa. ISA is the most suitable bus for 80x86. For systems using 80x86, only adding bus driver chips can basically meet the current requirements of ISA, and at the same time, we can also maximize the use of the current 80x86 supporting chips. Obviously, the price of these chips is also relatively appropriate

1.3 functional independence

modules are interconnected by bus, and the three buses and the off board bus are isolated by the bus driver chip between the template and the bus, so as to reduce the interference between the templates

the whole system can be divided into transaction module and data acquisition and processing module. The transactional module is completed by 80x86 and LonWorks network master CPU: processing network operations, protocol conversion; Human machine interface (such as keypad and LCD); Use the large-scale nonvolatile storage unit on the template to save the data on the data acquisition and processing module; Use the calendar clock and serial port on the board to complete other transactional operations; It can also operate some switch inputs and outputs to make up for the lack of input and output of the data acquisition and processing module. The data acquisition and processing module is mainly an intelligent a/d with DSP as the core. It undertakes the acquisition and processing of analog quantities and some important export control functions. There can be multiple data acquisition and processing modules in a system. Therefore, transaction processing module, data acquisition and processing module and input/output controlled by transaction processing module can effectively realize decentralized control and centralized management in a system

the independence of the system function also marks the improvement of the overall reliability of the system. The function of the main CPU is independent, and the function of the intelligent a/d is independent. All data conversion is realized through dual port RAM. The non catastrophic failure of either (such as the short circuit between power supply and ground due to chip breakdown) will not cause the failure of other templates. Each module runs independently, so that the templates can supervise each other

the independence of functions can be flexibly configured according to the size of the system. Systems with less transactional processing can use V40 as the main control module, and systems with more transactional processing can use 386EX, or even ST company 486pc. Similarly, the data acquisition and processing module can choose 16, 32, 64, or even more analog inputs, and can adopt high-performance such as TMS320C32, low-performance such as TMS320F206, or even 80C196. In all modules of the same type, except for the different main CPUs, we should strive to maintain the consistency of other hardware function modules, so that the software can be compatible at the compilation level in the main control module and at the C language level in other modules, which is convenient for the transplantation of user systems

2 intelligent communication

according to the characteristics of power system operation, the centerless control mode is adopted to make the control node as close as possible to the controlled equipment. Both the substation layer and the unit layer can use a unified LonWorks network, using the same communication protocol when there are too many oxide scales

the substation level includes the monitoring host and system of the whole station () for the monitoring of this station and the engineer station for network maintenance, which are generally installed in the control room. The equipment of the unit layer is generally placed on the site. According to the principle of distributed system, there is no circuit connection between the units, and data can be exchanged through peertopeer. When the monitoring and protection equipment of a unit fails or is abnormal, only the unit equipment can be stopped for inspection and processing, without affecting other units

lonworks technology, in line with ISO's 7-layer open network protocol, effectively solves interoperability problems. As a field bus, it has been well applied in substation automation system

3 main control module with 80x86 as the core

since the 1980s, PC with 80x86 as the core has been introduced successively, which is widely used in industrial control, office automation, commerce, home and other fields, and has also been applied in power system accordingly

v40 (upd70208) is a high-performance CMOS, fully static embedded 8-bit microprocessor chip (equivalent to 80188). V40 integrates many peripheral devices and is completely compatible with 8088CPU in software. 386EX is a 32-bit high-performance embedded CPU suitable for industrial control introduced by Intel in 1994. Using CMOS technology and static device design, it fully meets the requirements of low power consumption, high reliability and being able to be used in harsh environments in industrial sites

in addition to the above CPU, the main control module also includes bus part, system reset, power management, etc. Bus matching, bus driving and bus isolation mainly complete the isolation of the bus from the main control module, and ensure that the number of three bus driving chips is only related to the number of various detection instrument system modules produced by Jinan new era Gold Testing Instrument Co., Ltd. throughout the year. The reset output or input of the system can be used according to the demand. When the output mode is adopted, the master CPU can reset other templates; If the input mode is adopted, the system has a total level monitoring and watchdog reset output to reset and control other modules of the system

large capacity read-only electronic disk for storing user programs; Large capacity readable and writable electronic disk adopts DOC2000 of M-System company, and the maximum space can reach 100MB, which is used as large-scale data storage; Highly reliable readable nonvolatile memory, using highly reliable E2PROM, is used to store fixed values

the main CPU module also includes calendar clock, LCD control and keypad control, which can easily realize man-machine interface

4 digital signal processor dsp

dsp is different from the current general CPU. It is a microprocessor with special structure in order to achieve fast mathematical operation. Fast instruction cycle, Harvard structure, pipelined operation, special multiplier, special DSP instructions, and integrated circuit optimization design can make the instruction cycle of DSP reach 200ns

dsp has quite strong processing power. Under the same main frequency, it is even 10-50 times faster than the current personal computer. DSP is no longer simply used as data acquisition, but also shoulder the main computing functions previously completed by the main CPU. Intelligent a/d with DSP as the core can completely complete an independent function module in the power system. For example, in the current development situation of domestic plastic machinery industry, there are low independent innovation ability and few advanced and personalized special varieties. It can directly send protection actions through DSP without uploading to the main CPU, which can greatly speed up the response time of the system. Therefore, intelligent a/d has the function of switching value input/output at the same time

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