CN201255830Y

CN201255830Y - PLC automatic pre-synchronization module

Info

Publication number: CN201255830Y
Application number: CNU2008200422554U
Authority: CN
Inventors: 刘国敏; 王亦宁; 周霞
Original assignee: Nanjing NARI Group Corp; State Grid Electric Power Research Institute
Current assignee: Nari Technology Co Ltd; Nanjing NARI Group Corp; State Grid Electric Power Research Institute
Priority date: 2008-07-29
Filing date: 2008-07-29
Publication date: 2009-06-10
Anticipated expiration: 2018-07-29

Abstract

The utility model discloses a PLC automatic quasi-synchronizing module, which comprises a microprocessor CPU for real-timely collecting synchronized voltages and frequencies at two sides, to calculate voltage difference, frequency difference and phase angle difference and capture synchronous points; a voltage collection circuit for converting two alternative current input voltage signals into analogue signals adaptive to the internal A/D of the microprocessor CPU, and sending the signals to be collected by the internal A/D of the CPU, to be converted by the A/D into digital quantities to be read by the CPU; and a frequency and phase angle measurement circuit for filtering, rectifying and converting the two alternative current input voltage signals into square wave signals for frequency measurement. The PLC automatic quasi-synchronizing module has simple hardware circuit, can improve the reliability of local control unit of computer monitor system, and has simple wiring and simple debugging.

Description

A kind of PLC automatic presynchronization module

Technical field

The utility model relates to a kind of electric system and controls the module same period automatically, especially relates to a kind of PLC automatic presynchronization module.

Background technology

In China hydraulic power plant, realize that by computer supervisory control system making generator input coefficient paired running is the frequent regular job in generating plant to the generator quasi-synchronization paralleling.Present domestic hydraulic power plant computer supervisory control system local control unit great majority all adopt Programmable Logic Controller PLC to add the mode of microcomputer automatic sub-synchronous device, all control the startup of microcomputer automatic sub-synchronous device, realize synchronization paralleling operation two isolating switchs that independently are connected between the power-supply system such as unit and system, system and systems by Programmable Logic Controller PLC.Though adopt microcomputer automatic sub-synchronous device can improve greatly and net spee and combined floodgate accuracy, but because microcomputer automatic sub-synchronous device is a complete independent device, it is made up of hardware such as power-supply system, cpu system, Chinese LCD, voltage acquisition circuit, frequency and phase angle difference measurement loop, switching value input circuit, relay output loops, and therefore the reliability to microcomputer automatic sub-synchronous device has proposed very high requirement.

Domestic at present, external Programmable Logic Controller does not all have the automatic presynchronization module, and the PLC system itself that is made up of Programmable Logic Controller does not have automatic quasi-synchronization function, and the utility model has been filled up this blank, belongs to initiative.

Summary of the invention

1, goal of the invention

The purpose of this utility model is to provide a kind of PLC automatic presynchronization module.This automatic presynchronization module is a sub-module in the Programmable Logic Controller PLC system, a special function module.

2, technical scheme

The technical scheme that the utility model adopted is, the automatic presynchronization module adopts high performance microprocessor CPU to system with treat and side voltage and frequency are carried out real-time follow-up, accurately calculate weekly ripple system, treat and voltage difference, difference on the frequency, the phase angle difference of voltage, frequency and both sides, and carry out the adjusting of voltage, frequency automatically according to pressure reduction, frequency difference, so that pressure reduction, frequency difference are met the demands, capture the some same period rapidly, the isolating switch that closes reaches quick and stable and is incorporated into the power networks.

Realize that the technical scheme that the utility model purpose is adopted is, comprise microprocessor CPU, voltage acquisition circuit, frequency and phase angle difference measurement loop, relay output loop, LED light and serial communication loop.Wherein,

(1) microprocessor CPU is the core processing unit of automatic presynchronization module, mainly finishes the real-time collection to same period both sides voltage and frequency, calculates voltage difference, difference on the frequency, phase angle difference simultaneously; Catch the some same period; Finish and correspondingly leave signal and output indicator is provided.

(2) voltage acquisition circuit is that two voltage signals that exchange input are converted to the built-in A/D acceptable of microprocessor CPU analog signals, and delivers to the built-in A/D of CPU and gather, and is converted to digital quantity by A/D and reads to CPU.

(3) frequency and phase angle difference measurement loop is that two voltage signals that exchange input are converted to the timer conter that the square-wave signal that is used for frequency measurement enters CPU after filtering, shaping, and CPU catches rising edge by timer and calculates frequency and phase angle difference constantly.

(4) a plurality of same period Object Selection

Module can be supported a plurality of same period of object, and the same period parameters of each object can be set respectively, mutually between without any contact.

(5) relay output loop

The relay output loop is the outlet circuit to the output of being controlled by the object of the same period, output signal such as it comprises speedup, slows down, boosts, step-down, combined floodgate.

Frequency modulation and pressure regulation are left and are adopted traditional PID regulative mode output, regulate pulsewidth and are directly proportional with frequency difference and magnitude of pressure differential.

(6) serial communication loop

Module carries a serial ports, can link to each other with computing machine by debug serial port for module debugging usefulness, on computers, moves the module debugging software, can to the same period module synchronous loop demarcate, the same period parameters of each object is set respectively and start the same period.

(7) LED light

Be provided with a LED light panel on the module, its concrete implication is as follows: running indicator, CAN send lamp, CAN receiving light, trouble light, same period object pilot lamp, combined floodgate lamp, the lamp of failing, quicken lamp, the lamp that slows down, the lamp that boosts, step-down lamp, both sides input voltage signal phase angle difference pilot lamp.

3, beneficial effect

The utility model hardware circuit is simple, can improve computer supervisory control system local control unit reliability of operation greatly, and wiring simultaneously is simple, and debugging is convenient.

Description of drawings

Fig. 1 is a theory diagram of the present utility model.

Embodiment

(1) receive the object same period that the master control module issues by the CAN fieldbus, do not have the same period of pressure and the same period enabling signal;

(2) read the same period parameters of corresponding object according to the object same period that issues;

(3) gather selected same period of object both sides voltage and frequency in real time, calculate voltage difference, difference on the frequency, phase angle difference simultaneously;

(4) do not satisfy the same period during condition when frequency,, adopt traditional PID regulative mode to calculate the frequency modulation on pulse width, export governing system to, make frequency satisfy the condition that is incorporated into the power networks fast, reposefully according to the frequency difference size;

(5) do not satisfy the same period during condition when voltage, regulate, adopts traditional PID regulative mode to calculate the pressure regulation pulse width, export excitation system to according to magnitude of pressure differential, make voltage fast, the satisfied condition that is incorporated into the power networks reposefully.

(6) satisfy the same period during condition when voltage and frequency, capture the some same period fast, and predict best closing moment, and send closing pulse according to phase angle difference and the leading time gathered.

Claims

1, a kind of PLC automatic presynchronization module comprises frequency and phase angle difference measurement loop, relay output loop, LED light and serial communication loop, it is characterized in that, also comprise,

Microprocessor CPU is used for the real-time collection to same period both sides voltage and frequency, calculates voltage difference, difference on the frequency, phase angle difference, catches the some same period;

Voltage acquisition circuit is used for two voltage signals that exchange input are converted to the built-in A/D acceptable of microprocessor CPU analog signals, and delivers to the built-in A/D of CPU and gather, and is converted to digital quantity by A/D and reads to CPU;

Frequency and phase angle difference are measured the loop, are used for being converted to the square-wave signal that is used for frequency measurement after two voltage signal filtering that exchange input, the shaping.