CN203606455U - Partial discharge signal trigger phase synchronization clock source - Google Patents

Abstract

The utility model belongs to the technical field of high-voltage electrical device partial discharge online detection, and provides a partial discharge signal trigger phase synchronization clock source comprising an input signal unit, a shaping module, an acquisition card, a microprocessor and a USB communication module. The input signal unit comprises two paths of input signals, wherein one path of the signal is connected with the shaping module via a voltage-reducing module, and the other path is directly connected with the shaping module. The shaping module, the acquisition card and the USB communication module are respectively connected with the microprocessor. The USB communication module is communicated with an upper computer via an upper computer USB port. A sinusoidal signal inputted to the shaping module is processed into a square wave with the same frequency and phase. Counting values in the microprocessor are transmitted to the upper computer to be processed via the USB communication module and the upper computer USB port in turn by acquisition and counting of the microprocessor and triggering of an external clock. According to the clock source, system reliability is enhanced, and the acquired time difference precision can be controlled within 1 microsecond.

Description

Local discharge signal phase-triggered synchronous clock source

Technical field

The utility model belongs to high voltage electric equipment shelf depreciation online measuring technique field, relates to one in substation field Partial Discharge Detection, effectively catches trigger pip, the clock source of accurate recording local discharge signal generation phase place.

Background technology

In recent years, the application of partial discharge monitoring system in electrical network is increasingly extensive, takes on a certain scale.And superfrequency method (the English UHF that is called for short) is widely used detection means, measurement bandwidth is generally between 300MHz～1500MHz, it is strong that it has antijamming capability, the features such as sensitivity height, and this contactless metering system is all safer for secondary device and testing staff, system architecture is simple, be particularly suitable for on-line monitoring, thereby compare to other detection method and there is obvious advantage, large number quipments inherent vice case has been found by superfrequency on-line monitoring and live testing in all parts of the country in recent years, become one of most important detection means of the online detection field of current power equipment.

In the research field of power equipment fault detection of local discharge and diagnostic techniques, the phase information of local discharge signal is to analyze the important information of partial discharges fault pattern.The phase place obtain manner of traditional local discharge signal is mainly the phase place by local discharge signal and power frequency component synchronized sampling being calculated to local discharge signal, this mode requires sampling length must be greater than a power frequency period 20ms, this is for the required high sampling rate requirement of Partial Discharge Detection, can cause the efficiency of the whole detection system of the excessive impact of data volume and data analysis, and the collection of power frequency component need take an acquisition channel, waste hardware resource.The local discharge characteristic information that this data acquisition scheme obtains is on the other hand due to reasons such as sampling rate and the restrictions of data acquisition equipment storage depth, can only obtain amplitude and the phase information of signal, can not effectively analyze for the frequency information of local discharge signal.Can only take in this case the means that shorten acquisition time raising sampling rate to obtain complete local discharge signal, thereby discharge signal is carried out to necessary Time-Frequency Analysis.Each only 100 microsecond left and right that gather.Under this mode of operation, system cannot obtain local discharge signal phase-locking information accurately.For guaranteeing the mistiming precision of record, consider that the pulse width that capture card provides is only 100ns simultaneously.

Utility model content

Technique effect of the present utility model can overcome above-mentioned defect, and a kind of local discharge signal phase-triggered synchronous clock source is provided, and it has improved the mistiming precision collecting greatly.

For achieving the above object, the utility model adopts following technical scheme: it comprises input signal unit, Shaping Module, capture card, microprocessor, usb communication module, input signal unit comprises two-way input signal, wherein a road signal connects Shaping Module by voltage reduction module, another road is directly connected with Shaping Module, Shaping Module, capture card, usb communication module connects respectively microprocessor, usb communication module is communicated by letter with host computer by host computer USB port, the sinusoidal signal of input shaper module is processed into the square wave with frequency homophase, trigger by microprocessor acquisition counter and external clock, the count value of microprocessor internal is passed through to usb communication module successively, host computer USB port is passed to host computer and is processed.

System input can be chosen as by usb communication the sine wave signal of 220V civil power (50Hz power frequency component) or 50mV-5V by PC control.One tunnel is the 220V power frequency component that can normally obtain high-tension apparatus place.Another road is in the situation that cannot obtaining power frequency component, uses outside mutual inductance equipment to go out with synchronous small-signal frequency homophase as input signal from power frequency line influence.Signal to input is nursed one's health, shaping: for the 220V power frequency component entering, make its step-down by the form of electric resistance partial pressure, then, filtering phase-locked to the small-signal entering after step-down or from another road, is 3.5V square wave by filtered signal shaping; Square wave output adopts light-coupled isolation.

Preferably, microprocessor adopts STM32F103C8T6 model, and MCU design module has adopted the 32-bit microprocessor of ST company, has possessed inner accurate timing, external clock triggering, usb communication function.

Shaping Module comprises phase locking unit, wave filter, zero-crossing comparator.

Preferably, phase locking unit adopts CD4046 model.

Preferably, wave filter adopts SMCJ6A model.

Preferably, operational amplifier in zero-crossing comparator adopts LM211D model, zero-crossing comparator module be input as sine wave signal, after the filtering of offset of sinusoidal ripple, carry out zero crossing comparison, be output as synchronous square-wave signal.

Preferably, usb communication module adopts GL850A model, and usb communication module realizes host computer and triggers clock source, capture card synchronous communication.This equipment can be realized at most 5 road usb communications.

Local discharge signal phase-triggered synchronous clock source in the utility model adopts the high technical grade SOC processor of cost performance, so not only improve the reliability of system, the mistiming precision collecting can be controlled in 1 microsecond, there is important engineering significance for phase acquisition, the pattern-recognition of local discharge signal simultaneously.

Accompanying drawing explanation

Fig. 1 is modular structure schematic diagram of the present utility model;

Fig. 2 is microprocessor module schematic diagram of the present utility model;

Fig. 3 is zero-crossing comparator schematic diagram of the present utility model;

Fig. 4 is usb communication module principle figure of the present utility model.

Embodiment

As shown in Figure 1, local discharge signal phase-triggered synchronous clock source of the present utility model, comprise input signal unit, Shaping Module, capture card, microprocessor, usb communication module, input signal unit comprises two-way input signal, wherein a road signal connects Shaping Module by voltage reduction module, another road is directly connected with Shaping Module, Shaping Module, capture card, usb communication module connects respectively microprocessor, usb communication module is communicated by letter with host computer by host computer USB port, the sinusoidal signal of input shaper module is processed into the square wave with frequency homophase, trigger by microprocessor acquisition counter and external clock, the count value of microprocessor internal is passed through to usb communication module successively, host computer USB port is passed to host computer and is processed.

Microprocessor adopts STM32F103C8T6 model.Shaping Module comprises phase locking unit, wave filter, zero-crossing comparator.Phase locking unit adopts CD4046 model.Wave filter adopts SMCJ6A model.Operational amplifier in zero-crossing comparator adopts LM211D model.Usb communication module adopts GL850A model.

Precision interval clock unit timestamp record: the square wave upset after shaping is given to record as initial phase timestamp in the moment, count under MCU timer, again count while once overturning, and keep last count value upper, this value is counted for square-wave cycle.The moment that sends over trigger event at capture card is recorded the count value of current timer, and this numerical value is phase differential counting, and by usb communication, MCU receives by host computer and sends and ask for after instruction, and periodic quantity and phasometer numerical value are sent to host computer.

Usb communication module: to main frame uplink time stamp, complete basic communication function by host computer USB port; Management usb bus sequential.In the time that main frame master routine is started working, upload initial phase timestamp; Host computer control capture card carries out data acquisition with passage triggering mode, and in the time that shelf depreciation event occurs, the PFI1 port of data collecting card sends trigger pulse to trigger board and makes trigger board generation interruption, and in interruption processing procedure, trigger board records this Event Timestamp; Card to be collected completes and once gathers and uploaded after data to main frame by usb bus, and main frame sends the instruction of obtaining phase place and square-wave cycle to trigger board, and trigger board transmits the timestamp of trigger event to main frame by usb bus with interrupt mode.Phase differential=phasometer numerical value/square-wave cycle count value * 360.

In the Partial Discharge Detection of the power equipment of actual field, often run into such situation, outside exactly mutual inductance equipment go out from power frequency line influence synchronous small-signal burr phenomena serious, do not have good waveform characteristic.Therefore, need checking to trigger the square wave of clock source under disturbed condition and generate effect.

Measure phase difference precision analysis: because shelf depreciation can not guarantee there is generation in each power frequency period, and phase place while at every turn occurring is also not quite similar, so cannot verify with actual local discharge signal the phase differential precision in trigger pulse source.Here being its precision of checking, inputting a square-wave signal as the operating frequency phase information of nursing one's health after shaping, is the trigger pip of shelf depreciation event through the square wave of another road input after it is anti-phase, and it is carried out to phase difference calculating.The phase differential more at every turn calculating, the error of calculation.

Adopt single-chip microcomputer 4MHz timer to produce 2 road square waves, its phase differential remains on 180 degree, and side is 50Hz wave period:

External trigger square-wave signal (i.e. signal after reversion) constantly triggers system, and table 1 is the phase data that part gathers.

Table 1 single-chip microcomputer image data shows

Four, left side byte (as 01 36 B8) is square-wave cycle counting (N1), and four, the right byte is phase differential counting (N2), successively circulation.Phase differential D can be calculated by formula (1).

$D=\frac{N1}{N2}\×360$ Formula (1)

Optional 10 groups of data, as shown in table 2, calculate the phase differential of two square waves, thereby draw the precision of clock trigger board.Analytical calculation is known, and the measuring error of clock trigger board is very little, and average error is only 0.055 degree.

The precision analysis of table 2 clock trigger board

Claims (7)

1. a local discharge signal phase-triggered synchronous clock source, it is characterized in that, comprise input signal unit, Shaping Module, capture card, microprocessor, usb communication module, input signal unit comprises two-way input signal, wherein a road signal connects Shaping Module by voltage reduction module, another road is directly connected with Shaping Module, Shaping Module, capture card, usb communication module connects respectively microprocessor, usb communication module is communicated by letter with host computer by host computer USB port, the sinusoidal signal of input shaper module is processed into the square wave with frequency homophase, trigger by microprocessor acquisition counter and external clock, the count value of microprocessor internal is passed through to usb communication module successively, host computer USB port is passed to host computer and is processed.

2. local discharge signal phase-triggered synchronous clock source according to claim 1, is characterized in that, microprocessor adopts STM32F103C8T6 model.

3. local discharge signal phase-triggered synchronous clock source according to claim 1 and 2, is characterized in that, Shaping Module comprises phase locking unit, wave filter, zero-crossing comparator.

4. local discharge signal phase-triggered synchronous clock source according to claim 3, is characterized in that, phase locking unit adopts CD4046 model.

5. local discharge signal phase-triggered synchronous clock source according to claim 3, is characterized in that, wave filter adopts SMCJ6A model.

6. local discharge signal phase-triggered synchronous clock source according to claim 3, is characterized in that, the operational amplifier in zero-crossing comparator adopts LM211D model.

7. local discharge signal phase-triggered synchronous clock source according to claim 1 and 2, is characterized in that, usb communication module adopts GL850A model.

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