CN200976559Y

CN200976559Y - PLC controlled silicon still excitation control mechanism

Info

Publication number: CN200976559Y
Application number: CN 200620035306
Authority: CN
Inventors: 冯安; 彭加荣; 邓继建
Original assignee: Sichuan Dongfeng Electric Machinery Works Co Ltd
Current assignee: DEC Dongfeng Electric Machinery Co., Ltd.
Priority date: 2006-08-18
Filing date: 2006-08-18
Publication date: 2007-11-14
Anticipated expiration: 2016-08-18

Abstract

The utility model discloses a PLC Silicon-controlled rectifier static excitation control device, which comprises an excitation transformer, an excitation adjusting device, a power rectifier, a generators de-excitation and over voltage protection device and a re-excitation device; wherein, the excitation adjusting device is a programming controller; the excitation regulator steps comprise system initialization, control regulation, monitoring and protection. The utility model not only has the main advantages of microcomputer excitation system, but also has the advantages of high reliability, simple structure, low-cost, intelligent regulation and control. The utility model can be applicable to large and medium-sized hydro-generating groups self shunt excitation, self compound excitation or separated excitation silicon-controlled excitation control.

Description

PLC silicon-controlled static excitation controlling device

Technical field

The utility model relates to a kind of generator excitation unit, particularly relates to a kind of PLC silicon-controlled static excitation controlling device.

Background technology

In current electric power system, improve and keep the stability of synchronous generator operation, be one of primary condition that guarantees power system security, stable, economical operation.Excitation system is the important component part of synchronous generator unit, and synchronous generator needs a D.C. magnetic field in order to realize the conversion of energy, and the direct current that produces this magnetic field is called the exciting current of generator.According to the supply mode of exciting current, everyly obtain the generator of exciting current from other power supply, be called separately excited dynamo, from generator acquisition field power supply itself, then be called self-exciter.Excitation system directly influences the operation characteristic of generator, and good excitation system not only can guarantee the stable and reliability service of generator, and can improve the economic and technical norms of generator and electric power system effectively.Excitation system generally is made up of two parts, a part is used for providing direct current to the magnetic field of generator winding, to set up D.C. magnetic field, so-called exciting power output (or claiming the exciting power unit), another part is used for regulating exciting current when normally moving or breaking down, to satisfy the needs of safe operation, so-called excitation control section (or claiming excitation control unit or excitation regulation device), but the excitation regulation device of existing static excitation system adopts microcomputer as the control core mostly, and cost height, real-time are relatively poor.

Summary of the invention

The purpose of this utility model is to overcome the deficiencies in the prior art, and the silicon-controlled static excitation controlling device based on PLC that a kind of cost is low, reliability is high, real-time is provided.This silicon-controlled static excitation controlling device is at PLC (Programmable LogicController, programmable logic controller (PLC)) and under the control of internal applications, excitation transformer, rectifying device, rotor and magnetism elimination circuit to excitation system are comprehensively monitored and are regulated, guarantee generating set safety, stable, operation economically, be applicable to that big-and-middle-sized hydraulic generator unit is from shunt excitation, from compound excitation or the control of separate excitation thyristor excitation.

Goal of the invention of the present utility model is achieved through the following technical solutions: PLC silicon-controlled static excitation controlling device; comprise excitation transformer, excitation regulation device, power rectification device, eliminating magnetism of generator and overvoltage protection, excitation unit; described excitation regulation device is a Programmable Logic Controller; it comprises system initialization unit, regulating and controlling unit, monitoring and protected location; the system initialization unit is connected with the regulating and controlling unit respectively with monitoring and protected location, and the regulating and controlling unit is connected with motor demagnetization and overvoltage protection.Wherein, described system initialization unit comprises system parameters initialization, peripheral hardware initialization, manually or automatically regulates initialization, excitation initialization; Described regulating and controlling unit comprises that electric current and voltage sampling, default definite value comparison, PID regulate, control output; Described monitoring and protected location comprise excitation transformer monitoring and protection, rectifying device monitoring and protection, fan condition monitoring and protection, rotor and magnetism elimination circuit monitoring and protection.

The excitation transformer of generating set generally adopts the poured with epoxy resin dry-type transformer.The safe operation of dry-type transformer and useful life, depend on the safe and reliable of Transformer Winding insulation to a great extent.Winding temperature surpasses the insulation tolerable temperature makes insulation breakdown, is the one of the main reasons that causes the transformer cisco unity malfunction, and therefore monitoring and the controlling alarm thereof to the operating temperature of transformer is crucial.Measure temperature change value by the Pt100 thermistor that is embedded in the low pressure winding, carry out overtemperature alarm, tripping operation.

Rectifying device is monitored the throwing that comprises power cabinet and is moved back, melts soon the monitoring in fusing, rectifier bridge brachium pontis electric current, controllable silicon open angle, controllable silicon shell temperature, resistance-capacitance protection loop etc. etc.

Fan monitor comprises that the throwing of the monitoring of blower fan wind-warm syndrome monitoring, blast and blower fan is moved back and fault etc.

The monitoring of rotor and magnetism elimination circuit comprises rotor insulation monitoring, temperature of rotor monitoring demagnetization record ripple, the monitoring of field suppression switch action frequency, the monitoring of controllable silicon jumper action frequency, fast molten fusing monitoring etc.

PLC silicon-controlled static excitation controlling device described in the utility model removes the major advantage with microcomputer excitation system if can realize new modern control technology, as optimal control, adaptive control etc., to improve outside the control performance etc., also has following advantage:

(1) reliability height.The microcontroller excitation system, because of the microprocessor poor anti jamming capability, the problem that has microprocessor " deadlock " in case be interfered, so the microcomputer excitation system all uses multichannel multi-microcomputer technology to improve the reliability of system at present, so system is with regard to more complicated, cost increases, and PLC is because the characteristics of its working method, operation principle have very high antijamming capability, so adopt the excitation system of PLC technology to have very high reliability.

(2) simple in structure.Because the reliability height of PLC, there is not the problem of " deadlocks " in antijamming capability, thus do not need many " PLC " technology of multichannel and multichannel to improve the reliability of system, so system's formation is simply.PLC finishes the phased unsteady flow of high-speed real-time control electric power, and phase shifting accuracy reaches 0.02 °, has saved conventional same phase-shift circuit, and excitation system has a lot of relay operation simultaneously, and the PLC excitation system is finished relay operation by PLC, and it is more simple that operating system is constituted.

(3) intelligent adjusting and control are flexibly.Current PLC arithmetic speed is very high, control command is abundant, have functions such as floating-point operation, pointer computing, interrupt response, for intelligent real-time regulated provides physical basis, simultaneously because the distinctive relay logic function of PLC, intelligent real-time regulated and relay logical operation can be combined, make that system's control is flexible and changeable.

(4) powerful network function.The network function of PLC is very strong, not only can also can networking with upper machine communication but also PLC self, have very strong autgmentability, opening.

Description of drawings

Fig. 1 structured flowchart of the present utility model

The structured flowchart of Fig. 2 PLC excitation regulation device

Fig. 3 system master flow chart

Fig. 4 system initialization flow chart

Fig. 5 regulating and controlling flow chart

Fig. 6 PID regulates flow chart

Fig. 7 monitoring and protection flow chart

Fig. 8 accident and restriction monitoring flow chart

Embodiment

Further describe the technical solution of the utility model below in conjunction with accompanying drawing.As Fig. 1, PLC silicon-controlled static excitation controlling device comprises excitation transformer, excitation regulation device, power rectification device, eliminating magnetism of generator and overvoltage protection, excitation unit.

As Fig. 2, described excitation regulation device is a Programmable Logic Controller, and it comprises central processor CPU, read-only memory block, read-write memory block, four tunnel analog quantity input modules, one road analog output module, ten four-way switch amount input modules, 11 way switch amount output modules and RS-232 interface module.

As Fig. 3, the regulating and controlling step of excitation regulation device comprises system initialization, regulating and controlling, monitoring and protection.

As Fig. 4, described system initialization step comprises system parameters initialization, peripheral hardware initialization, manually or automatically regulates initialization, excitation initialization.

As Fig. 5, described regulating and controlling step comprises that electric current and voltage sampling, default definite value comparison, PID regulate, control output.

The flow chart that Fig. 6 regulates for PID.Wherein, system adopts the increment type PID regulative mode, and its control method is the analog signal quantification with feedback, compare with set-point, in deviate substitution PID arithmetic expression, calculate this deviation output variable, with the output signal addition of last time, promptly get this output variable then.

Fig. 7 is monitoring and protection flow chart, and it comprises excitation transformer monitoring, rectifying device monitoring, fan condition monitoring, PT disconnection monitoring and steps such as rotor and magnetism elimination circuit monitoring.

Fig. 8 is accident and restriction monitoring flow chart.Wherein, after data acquisition finishes, the value that presets respectively compares, in order to improve the reliability of detection, after detecting the scope of data above setting, postpone to judge again behind the certain hour, delay time the back if data still exceed the scope of setting, think that then this accident detects effectively, and corresponding accident sign is changed to effectively, if wherein once data are got back in the setting range, then corresponding sign is reduced.This is " going shake " design, adopts this detection method, can increase the reliability and stability of system greatly, reduces the misoperation that external disturbance is brought.

Claims

1, PLC silicon-controlled static excitation controlling device; comprise excitation transformer, excitation regulation device, power rectification device, eliminating magnetism of generator and overvoltage protection, excitation unit; it is characterized in that: described excitation regulation device is a Programmable Logic Controller; it comprises system initialization unit, regulating and controlling unit, monitoring and protected location; the system initialization unit is connected with the regulating and controlling unit respectively with monitoring and protected location, and the regulating and controlling unit is connected with motor demagnetization and overvoltage protection.

2, PLC silicon-controlled static excitation controlling device according to claim 1 is characterized in that: described system initialization unit comprises system parameters initialization module, peripheral hardware initialization module, manually or automatically regulates initialization module, excitation initialization module.

3, PLC silicon-controlled static excitation controlling device according to claim 1 is characterized in that: described regulating and controlling unit comprises electric current and voltage sampling module, default definite value comparison module, PID adjustment module, control output module.

4, PLC silicon-controlled static excitation controlling device according to claim 1 is characterized in that: described monitoring and protected location comprise excitation transformer monitoring and protection module, rectifier bridge monitoring and protection module, fan condition monitoring and protection module, magnetism elimination circuit monitoring and protection module.