CN108565832A - A kind of transformer excitation flow restraining device - Google Patents

Abstract

The present invention discloses a kind of transformer excitation flow restraining device; to realize that 110kV Above Transmission Lines are when realizing current comparison pilot protection in relay protection of power system; current value will not generate mutation by excitation surge current caused by no-load transformer is put on circuit measured by current transformer, it is ensured that protective relaying device action correctness.The magnetizing inrush current suppression device is made of power module, CPU module, data memory module, data disaply moudle and encrypting module.The present invention relates to the technical fields such as relay protection, power system transient stability, power electronic technique.The present invention is directed to traditional current comparison pilot protection and generates malfunction when no-load transformer is put into; protective relaying device loses the problems such as correctness; pass through the control to transformer remanent magnetism and air-drop angle; to inhibit three phase excitation to shove, transformer steadily enters steady-state operation when realizing transformation cataclysm in electric system.

Description

A kind of transformer excitation flow restraining device

Technical field

The present invention relates to global design and the software algorithms of a kind of transformer excitation flow restraining device, including system Design.Belong to the technical fields such as electric system, relay protection, power electronics.

Background technology

Transformer is electrical equipment important in electric system, and when system jam, fault current can be to transformer Operation produces serious influence, or even burns transformer.Relay protection device is to ensure setting for power system security stable operation It is standby, by the use of longitudinal differential protection, the transformer influenced by failure can be quickly and effectively cut off in failure.Due to transformation The self construction of device will produce a prodigious excitation surge current, the meeting of excitation surge current when no-load transformer input coefficient The judgement that mistake is generated when protective relaying device being made to carry out breakdown judge, influences the reliability of relay protection device.

Relay protection device generally escapes excitation surge current by the way of secondary harmonic brake at present, that is, detects two in circuit Order harmonic components are latched breaker if a large amount of second harmonics can be detected in the line, prevent it from malfunction occurs.But it encourages Magnetic, which shoves, to be still existed in power grid, and power grid is polluted, and deteriorates power quality, and network voltage is caused to rise sharply or rapid drawdown；It induces and answers It shoves, interferes neighbouring transformer station high-voltage side bus；Switching overvoltage is induced, electrical equipment is damaged, or even makes each side load cut-out of transformer, Cause power outage.

Protection misoperation caused by avoid excitation surge current exits protection or excitation occurs and gushes when using air-drop transformer Guard delay action all can make equipment cause certain harm when stream.And is differentiated when excitation surge current occurs, analysed whether For the method for fault current, the accuracy and accuracy requirement to algorithm are high.So far there is no a kind of algorithms being widely recognized as.

In actual conditions, even if excitation surge current can be accurately identified by having, it is ensured that the device of protection not malfunction can not also be eliminated The influence that excitation surge current generates other aspects.

The size of the excitation surge current generated when can significantly reduce no-load transformer input by the exciting surge suppressor.

Invention content

According to above-mentioned design, the present invention uses following technical proposals：

The CPU module uses chip C8051F020；The memory module uses FM24C512；The input module The secondary side of collection capacity voltage transformer and current transformer in circuit；The display module uses Liquid Crystal Module 19264ALCM graphic dot matrix liquid crystal displays；The encrypting module, which uses, has DES asymmetrical encryption algorithm CrytoMemory Chip；The MOSFET module boards use CSD88584Q5DC.

Transformer excitation flow restraining device controls transformer and puts into the specific steps of power grid such as in most suitable switching angle α Under：

(1) device is instructed by being sent to the separating brake of transformer outside samplers sample and is sent to CPU module；

(2) phase angle of each phase voltage is analyzed and is recorded when CPU module is to the separating brake of samplers sample；

(3) when device again by close a floodgate order when, CPU according to the separating brake phase angle of each phase voltage of last registration and Originally the closing time of input constraint device is compared calculating；

(4) CPU can effectively inhibit the switching angle of excitation surge current and transmit signal extremely according to result of calculation analysis is compared MOSFET modules；

(5) when system voltage reaches the combined floodgate angle of CPU calculating, breaker actuation is controlled by MOSFET modules.

The specific processing step that CPU is compared the voltage signal acquired twice in the step (3) is as follows：

(1) transformer is in normal operating conditions, due to exciting current difference, may be operated in magnetic hysteresis of different sizes and return On line, the maximum and minimum of hysteresis loop when estimating normal operation are calculated magnetic hysteresis and returned by transformer excitation flow restrainable algorithms Line expression formula；

(2) when transformer is due to failure or maintenance disconnection, IEA records phase when a certain phase voltage disconnects, due to magnetic In 90 ° of voltage after logical, it can be deduced that transformer remanent magnetism is estimated at the phase angle of magnetic flux when transformer disconnects；

(3) it when transformer is put into again, calculates and inhibits inrush current push-pull angle α, when delay waits for voltage-phase to meet condition Signalizing activity is sent out, transformer is quickly put into.

The foundation of transformer excitation flow restrainable algorithms is as follows in the step (2)：

(1) by algorithm abstraction at four operating statuses, i.e. transformer station high-voltage side bus (TYX), transformer disconnects (TDK), waits for 1 (DD1) and wait for 2 (DD2)；

(2) when transformer normal operation, discrete Tokken is located at library TYX, and DD1 is transferred to if C_OP orders occur；

(3) judge WI conditions by detecting sampled current signals in TYX and DD1 states；

(4) meet condition and enter TDK states, use JS0 function corner cuts immediately；

(5) entered DD states by C_CL orders, control and close a floodgate when voltage-phase reaches switching angle, restore transformer fortune Row state TYX.

The present invention is compared with prior art compared with having the advantages that：

(1) transformer, capacitor and the air-drop of transmission line of electricity three-phase no-flashy-flow can be achieved；

(2) it goes respectively to press with transformation and measures line Cooperation with Relay, realizes when short trouble excision occurs in inhibition because of busbar The excitation surge current that voltage abruptly increase generates avoids false protection that whole outlets is caused to have a power failure；

(3) piece magnetic polarity when being dropped by detection to remanent magnetism in Three-Phase Transformer magnetic circuit and control realizes suppression completely Three phase excitation processed is shoved；

(4) residual voltage when being powered off by sensing capacitor, and the polarity of charging voltage is realized when control air-drop combined floodgate No impact puts into operation；

(5) three-phase shoves real-time recording ' '

(6) mating with protective relaying device and measure and control device, realize transformer, capacitor, the control of circuit no-flashy-flow switching；

(7) have and be set and controlled with complex automatic system communication function, a realization distant place；

(8) it supports spare transformation to go to run by cold standby mode, saves a large amount of no-load loss；

(9) power grid harmonic wave interference is purified, the power grid rapid drawdown because of initiation of shoving is eliminated, improves all kinds of protections and automation equipment Job stability.

Description of the drawings

Fig. 1 is exciting surge suppressor schematic diagram.

Fig. 2 is exciting surge suppressor hardware effort schematic diagram.

Specific implementation mode

The specific implementation of the present invention is described with reference to the drawings as follows：

As shown in Figure 1, power module provides power input for exciting surge suppressor.Voltage transformer and current transformer When being worked normally in detection circuit and electric current when non-normal working and voltage and the signal of acquisition is passed into CPU stores And analysis.CPU calculates the best switching angle of transformer switching by algorithm, by the way that signal is passed to MOSFET modules, and The switching of transformer is realized by MOSFET module actions and breaker.

Embodiment one：

Referring to Fig. 2, transformer excitation flow restraining device CPU module (1), input module (3), is shown memory module (2) Show module (4), encrypting module (5) and MOSFET module boards (6) composition, which is characterized in that the CPU module (1) completes logarithm The signal processing analysis that word signal processor DSP unit is sent；The memory module (2) is walked using 2 thread industrial standards and is connect Mouth FRAM；The input module (3) include in reception system the electrical quantity sensor such as voltage transformer TV and current transformer with And the input equipments such as keyboard；The display module (4) uses Dot-Matric LCD Display, is shown to collection capacity and controlled quentity controlled variable；Institute Encrypting module (5) is stated using encrypted memory and suppressor is protected using Encryption Algorithm；The MOSFET module boards (6) It is formed using driving circuit and MOSFET element；The input module (3) is connected in CPU module (1), and to input quantity into Row Algorithm Analysis judges；Liquid crystal display in the display module (4) is connected to CPU module (1) by serial ports；It is described MOSFET module boards (6) receive the switching on and off instruction that CPU module (1) is sent out, and realize the control to breaker.

Embodiment two：

The present embodiment and embodiment one are essentially identical, and special feature is：The CPU module (1) uses chip C8051F020；The memory module (2) uses FM24C512；It is mutual that input module (3) collection capacity comes from voltage in circuit The secondary side of sensor and current transformer；The display module (4) uses Liquid Crystal Module 19264ALCM graphic dot matrix liquid crystal displays Device；The encrypting module (5) is using with DES asymmetrical encryption algorithm CrytoMemory chips；The MOSFET module boards (6) CSD88584Q5DC is used.

Claims (5)

1. a kind of transformer excitation flow restraining device CPU module (1), memory module (2), input module (3), display module (4), encrypting module (5) and MOSFET module boards (6) composition, which is characterized in that the CPU module (1) is completed to digital signal The signal processing analysis that processor DSP unit is sent；The memory module (2) walks interface FRAM using 2 thread industrial standards； The input module (3) includes the electrical quantity sensor and keyboard etc. such as voltage transformer TV and current transformer in reception system Input equipment；The display module (4) uses Dot-Matric LCD Display, is shown to collection capacity and controlled quentity controlled variable；The encryption mould Block (5) is protected suppressor using encrypted memory and using Encryption Algorithm；The MOSFET module boards (6) are using driving Circuit and MOSFET element composition；The input module (3) is connected in CPU module (1), and carries out Algorithm Analysis to input quantity Judge；Liquid crystal display in the display module (4) is connected to CPU module (1) by serial ports；The MOSFET module boards (6) the switching on and off instruction that CPU module (1) is sent out is received, realizes the control to breaker.

2. transformer excitation flow restraining device according to claim 1, which is characterized in that the CPU module (1) uses Chip C8051F020；The memory module (2) uses FM24C512；Input module (3) collection capacity comes from electricity in circuit Press the secondary side of mutual inductor and current transformer；The display module (4) uses Liquid Crystal Module 19264ALCM graphic dot matrix liquid crystal Display；The encrypting module (5) is using with DES asymmetrical encryption algorithm CrytoMemory chips；The MOSFET modules Plate (6) uses CSD88584Q5DC.

To it when 3. transformer excitation flow restraining device puts into no-load transformer using technical method described in claim 1 The control of remanent magnetism and air-drop angle, transformer is steadily as follows into stable state when realizing voltage cataclysm：

(1) device is instructed by being sent to the separating brake of transformer outside samplers sample and is sent to CPU module；

(2) phase angle of each phase voltage is analyzed and is recorded when CPU module is to the separating brake of samplers sample；

(3) when device again by close a floodgate order when, CPU is according to the separating brake phase angle of each phase voltage of last registration and original The closing time of input constraint device is compared calculating；

(4) CPU can effectively inhibit the switching angle of excitation surge current and transmit signal to MOSFET according to result of calculation analysis is compared Module；

(5) when system voltage reaches the combined floodgate angle of CPU calculating, breaker actuation is controlled by MOSFET modules.

4. transformer excitation flow restraining device according to claim 3, it is characterised in that CPU is to twice in step (3) The specific processing step that the voltage signal of acquisition is compared is as follows：

(1) transformer is in normal operating conditions, due to exciting current difference, may be operated in hysteresis loop of different sizes On, the maximum and minimum of hysteresis loop when estimating normal operation are calculated hysteresis loop by transformer excitation flow restrainable algorithms Expression formula；

(2) when transformer is disconnected due to failure or maintenance, IEA records phase when a certain phase voltage disconnects, due to magnetic flux it Afterwards in 90 ° of voltage, it can be deduced that transformer remanent magnetism is estimated at the phase angle of magnetic flux when transformer disconnects；

(3) it when transformer is put into again, calculates and inhibits inrush current push-pull angle α, delay is sent out when voltage-phase being waited for meet condition Signalizing activity quickly puts into transformer.

5. according to the transformer excitation flow restraining device described in claim 4, it is characterised in that (1) static exciter is gushed in The foundation of restrainable algorithms is flowed, concrete mode is：

(1) by algorithm abstraction at four operating statuses, i.e. transformer station high-voltage side bus (TYX), transformer disconnects (TDK), waits for 1 (DD1) With 2 (DD2) of waiting；

(2) when transformer normal operation, discrete Tokken is located at library TYX, and DD1 is transferred to if C_OP orders occur；

(3) judge WI conditions by detecting sampled current signals in TYX and DD1 states；

(4) meet condition and enter TDK states, use JS0 function corner cuts immediately；

(5) entered DD states by C_CL orders, control and close a floodgate when voltage-phase reaches switching angle, restore transformer station high-voltage side bus shape State TYX.