CN104280644A - Direct-current transmission project typical transient fault recognizing method - Google Patents

Abstract

The invention discloses a direct-current transmission project typical transient fault recognizing method. The method is characterized by comprising the following steps that (1) data signals of a fault recorder are extracted and a fault electrode is judged; (2) direct-current-side voltage and current signals of the fault electrode are extracted, characteristic quantity extraction is conducted on waveforms, and at least one primary fault type is obtained after characteristic quantity matching is conducted according to a fault characteristic quantity library established in advance; (3) according to the waveform data time interval stored in a fault waveform sample library established in advance, sampling is conducted on the recorded waveforms of the fault electrode from the fault starting moment, sampling values are matched with waveform data corresponding to the primary fault types and located in the fault waveform sample library to obtain waveform similarity coefficients, and the fault type with the highest similarity is used as the final recognizing result. The direct-current transmission project typical transient fault recognizing method improves the fault checking efficiency and guarantees safe and stable operation of a direct-current transmission system.

Description

The recognition methods of a kind of DC transmission engineering typical case transient fault

Technical field

The present invention relates to the recognition methods of a kind of DC transmission engineering typical case transient fault.

Background technology

D.C. high voltage transmission (HVDC), be utilize galvanic current to have without induction reactance, capacitive reactance is also inoperative, the high-power remote direct current transportation adopted without advantages such as stationary problems.The advantage of D.C. high voltage transmission in long-distance and large-capacity power transmission makes it be applied widely in China.Because HVDC Converters device category is various, major loop and Control protection system complex structure, easily bear superpotential threat because of apparatus insulated and cause DC system fault or stoppage in transit, the safe operation of serious threat regional power grid.

Cause the superpotential reason of current conversion station equipment can be divided into three kinds, i.e. current conversion station AC fault, valve district fault and current conversion station DC side fault, wherein, because AC fault signature is obvious, easily carried out the identification of fault type by the change of AC voltage.And for full voltage starting, ground connection polar curve open circuit, metallic return open circuit, inverter side locking and bypass to not unlocking, noble potential YY converter transformer valve side single-line to ground fault etc. is due to Control protection is malfunctioning or short circuit, open circuit cause valve district and current conversion station DC side fault; its fault characteristic is complicated, is difficult to directly differentiate it.

Current high voltage direct current transmission project generally adopts the polar curve of fault fluid parameter (both positive and negative polarity of direct current) electric current and voltage to carry out the identification of fault, and fault fluid parameter have recorded analog quantity and the digital quantity waveform of primary side and secondary side many places after fault, need when carrying out malfunction elimination to do a large amount of analytical works, operand is large, the investigation inefficiency of causing trouble.

Summary of the invention

For the problems referred to above, the invention provides the recognition methods of a kind of DC transmission engineering typical case transient fault, make full use of the data of fault fluid parameter record, in conjunction with the feature of typical transient fault, form Fault Identification algorithm, improve the investigation efficiency of fault, ensure the safe and stable operation of DC transmission system.

For realizing above-mentioned technical purpose, reach above-mentioned technique effect, the present invention is achieved through the following technical solutions:

The recognition methods of a kind of DC transmission engineering typical case transient fault, is characterized in that, comprise the steps:

(1) extract the data-signal of fault fluid parameter, carry out the differentiation of fault pole;

(2) extract DC voltage, the current signal of fault pole, Characteristic Extraction is carried out to waveform, carries out characteristic quantity coupling according to the fault characteristic value storehouse set up in advance, obtain at least one preliminary fault type;

(3) according to the Wave data time interval stored in the fault waveform Sample Storehouse set up in advance, the record waveform of fault pole is sampled from fault initial time, successively sample value is mated with Wave data corresponding with preliminary fault type in fault waveform Sample Storehouse, ask for waveform similarity coefficient, using fault type the highest for similarity as the final result identified.

Preferably, each step is specific as follows:

Step (1) specifically comprises the steps:

Step 101: extract the electrode line of fault fluid parameter output and the data-signal of negative line;

Step 102: differentiate the very fault pole that there occurs phase shift locking or restart action.

Step (2) specifically comprises the steps:

Step 201: judge the slope variation of fault pole DC voltage and DC current, obtains fault moment;

Step 202: the voltage data adopting FFT conversion process polar curve;

Step 203: the variation tendency of analysis of failure moment each DC voltage and DC current;

Step 204: the overall variation trend of DC voltage and DC current after analysis of failure;

Step 205: according to step 202 to the result of step 204, carry out characteristic quantity with fault characteristic value storehouse and mate, obtain at least one preliminary fault type.

In step (3), ask for waveform similarity coefficient ρ _xyformula as follows:

${\mathrm{\ρ}}_{\mathrm{xy}}=\frac{\mathrm{\ΣX}\left(n\right)Y\left(n\right)}{\sqrt{\mathrm{\Σ}{X}^2\left(n\right)\mathrm{\Σ}{Y}^2\left(n\right)}}$

In formula, X (n) is sample waveform data, and Y (n) is wave-recording sampling data;

Be averaging the related coefficient of each waveform, the maximum fault type of average correlation coefficient is the final result identified.

This method makes full use of the data of fault fluid parameter record, and utilize the feature of typical transient fault and identify fault fast with the Waveform Matching of the sample waveform of fault waveform Sample Storehouse, greatly improve the malfunction elimination efficiency of DC transmission engineering, algorithm realization is simple.

The invention has the beneficial effects as follows: the data making full use of fault fluid parameter record, in conjunction with the feature of typical transient fault, form Fault Identification algorithm, improve the investigation efficiency of fault, ensure the safe and stable operation of DC transmission system.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of a kind of DC transmission engineering typical case of the present invention transient fault recognition methods.

Embodiment

Below in conjunction with accompanying drawing and specific embodiment, technical solution of the present invention is described in further detail, can better understand the present invention to make those skilled in the art and can be implemented, but illustrated embodiment is not as a limitation of the invention.

The fault recorder data of the fault fluid parameter of the ABB AB commonly used for Domestic Direct Current Transmission engineering below, introduce DC transmission engineering Typical over-voltage transient fault in detail (specifically to comprise: full voltage starting, rectification side ground connection polar curve open circuit under the monopolar ground return method of operation, inversion side joint ground polar curve open circuit under the monopolar ground return method of operation, metallic return is opened a way, rectification side high-end YY converter transformer valve side single-phase grounding fault, inverter side high-end YY converter transformer valve side single-phase grounding fault, inverter side locking and bypass are to not unlocking, line-to-ground short circuit) recognition methods, specifically comprise the steps, as shown in Figure 1:

(1) extract the data-signal of fault fluid parameter, carry out the differentiation of fault pole:

The output packet of fault fluid parameter contains the data-signal of positive pole and negative pole, extracts polar curve DC voltage and the DC current signal of fault fluid parameter.

For causing the superpotential typical transient fault of current conversion station, after D.C. high voltage transmission breaks down, protection act is in phase shift locking or restart fault pole, is differentiated the very fault pole that there occurs above action by DC voltage and DC current.

(2) typical transient fault tentatively identifies:

Extract the polar curve DC voltage (UDL) of fault pole, polar curve DC current (IDL), neutral bus voltage (UDN), neutral bus electric current (IDNC), earth current (IDNE) signal, slope variation analysis is carried out to polar curve DC voltage waveform, fft analysis, analyze the above variation tendency of each parameter after instant of failure and fault, form the characteristic quantity list of recorder data, characteristic quantity coupling is carried out according to the fault characteristic value storehouse set up in advance, obtain at least one preliminary fault type, realize the screening to fault type, this time recognition result may not be unique.

Wherein, this method needs to set up in advance a large Mishap Database; the fault waveform Sample Storehouse of the fault characteristic value storehouse specifically comprising the feature comprising each typical fault and the waveform comprising each typical fault; fault characteristic value storehouse is set up by mechanism research and simulation research; fault waveform Sample Storehouse then can pass through RTDS (Real Time Digital Simulator, real-time digital simulator) emulation, the electromagnetic transient simulation considering working control protection feature or physical fault recorder data and set up.

Preferably, step (2) specifically comprises the steps:

Step 201: judge the slope variation of fault pole DC voltage and DC current, obtains fault moment;

Step 202: the voltage data adopting FFT conversion process polar curve, i.e. UDL data;

Step 203: the variation tendency of analysis of failure moment each DC voltage and DC current, the i.e. variation tendency of analysis of failure moment UDL, IDL, UDN, IDNC, IDNE;

Step 204: the overall variation trend of DC voltage and DC current after analysis of failure, namely analyzes the overall variation trend of UDL, IDL, UDN, IDNC, IDNE in the whole record ripple time period;

Step 205: according to step 202 to the result of step 204, carry out characteristic quantity with fault characteristic value storehouse and mate, obtain at least one preliminary fault type.

Judge that the algorithm of preliminary fault type is as follows:

1) if the neutral bus electric current in recorder data is less than 0.1p.u. within the whole analysis period, i.e. IDNC<0.1p.u. is then full voltage starting fault;

2) if containing 50HZ component in polar curve DC voltage, namely the frequency spectrum of UDL has 50HZ component, and instant of failure inverter side line voltage rises, polar curve electric current and neutral bus electric current all decline, then for inverter side locking and bypass are to not unlocking fault;

3) if instant of failure inverter side line voltage, polar curve electric current and neutral bus electric current all decline, namely inverter side UDL, IDL, IDNC decline, be then rectification side ground connection polar curve open fault, rectification side high-end YY converter transformer valve side single-phase grounding fault or metallic return open fault under the monopolar ground return method of operation;

4) if inverter side earthing pole line current drops to 0 within 1ms, i.e. IDNE=0 is then the inverter side ground connection polar curve open fault under the monopolar ground return method of operation;

5) if neutral bus electric current drops to 0 within 1ms, i.e. IDNC=0 is then inverter side noble potential YY converter transformer valve side single-phase grounding fault;

6) if direct-current polar voltage, electric current drop to be less than 0.1p.u., namely UDL and IDL drops to and is less than 0.1p.u., and rises again after a period of time or restart, be then line-to-ground short trouble.

(3) final identification types is obtained by Waveform Matching:

According to the Wave data time interval stored in the fault waveform Sample Storehouse set up in advance, the record waveform of fault pole is sampled from fault initial time, T.T. length and the time duration of sample waveform of storage be consistent, successively sample value is mated with Wave data corresponding with preliminary fault type in fault waveform Sample Storehouse, waveform similarity coefficient ρ can be carried out according to formula below _xyask for,

${\mathrm{\&rho;}}_{\mathrm{xy}}=\frac{\mathrm{\&Sigma;X}\left(n\right)Y\left(n\right)}{\sqrt{\mathrm{\&Sigma;}{X}^2\left(n\right)\mathrm{\&Sigma;}{Y}^2\left(n\right)}}$

In formula, X (n) is sample waveform data, and Y (n) is wave-recording sampling data.

Be averaging the related coefficient of each waveform, the maximum fault type of average correlation coefficient is the final result identified, by the highest fault type of similarity as the final fault type identified.

Compared to voltage, the electric current of direct-current polar of only sampling in the past, carry out fault recognition method by the time frequency analysis of complexity, this recognition methods takes full advantage of the feature of fault itself, carries out Primary Location by the fault signature of faults topology information to fault.Make full use of the existing data of fault fluid parameter, Waveform Matching is carried out to fault waveform, algorithm realization is simple, improve Fault Identification accuracy, and when having carried out fault type preliminary screening by fault signature, recognition effect is remarkable, improves the investigation efficiency of fault, ensures the safe and stable operation of DC transmission system.

These are only the preferred embodiments of the present invention; not thereby the scope of the claims of the present invention is limited; every utilize instructions of the present invention and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in the technical field that other are relevant, be all in like manner included in scope of patent protection of the present invention.

Claims (6)

1. a DC transmission engineering typical case transient fault recognition methods, is characterized in that, comprise the steps:

(1) extract the data-signal of fault fluid parameter, carry out the differentiation of fault pole;

(2) extract DC voltage, the current signal of fault pole, Characteristic Extraction is carried out to waveform, carries out characteristic quantity coupling according to the fault characteristic value storehouse set up in advance, obtain at least one preliminary fault type;

(3) according to the Wave data time interval stored in the fault waveform Sample Storehouse set up in advance, the record waveform of fault pole is sampled from fault initial time, successively sample value is mated with Wave data corresponding with preliminary fault type in fault waveform Sample Storehouse, ask for waveform similarity coefficient, using fault type the highest for similarity as the final result identified.

2. a kind of DC transmission engineering typical case transient fault according to claim 1 recognition methods, it is characterized in that, step (2) specifically comprises the steps:

Step 201: judge the slope variation of fault pole DC voltage and DC current, obtains fault moment;

Step 202: the voltage data adopting FFT conversion process polar curve;

Step 203: the variation tendency of analysis of failure moment each DC voltage and DC current;

Step 204: the overall variation trend of DC voltage and DC current after analysis of failure;

Step 205: according to step 202 to the result of step 204, carry out characteristic quantity with fault characteristic value storehouse and mate, obtain at least one preliminary fault type.

3. a kind of DC transmission engineering typical case transient fault according to claim 2 recognition methods, is characterized in that, judge that the algorithm of preliminary fault type is as follows:

1) if the neutral bus electric current in recorder data is less than 0.1p.u. within the whole analysis period, be then full voltage starting fault;

2) if containing 50HZ component in polar curve DC voltage, and instant of failure inverter side line voltage rises, polar curve electric current and neutral bus electric current all decline, then for inverter side locking and bypass are to not unlocking fault;

3) if the electric current of the voltage of inverter side polar curve and the neutral line, electric current and ground connection polar curve all declines, be then rectification side ground connection polar curve open fault, rectification side high-end YY converter transformer valve side single-phase grounding fault or metallic return open fault under the monopolar ground return method of operation;

4) if inverter side earthing pole line current drops to 0 in 1ms after a failure, be then inversion side joint ground polar curve open fault under the monopolar ground return method of operation;

5) if neutral bus electric current drops to 0 within 1ms after a failure, be then inverter side noble potential YY converter transformer valve side single-phase grounding fault;

6) if direct-current polar electric current and voltage drops to be less than 0.1p.u., and rising again after a period of time or restart, is then line-to-ground short trouble.

4. a kind of DC transmission engineering typical case transient fault according to claim 1 recognition methods, is characterized in that, in step (3), ask for waveform similarity coefficient ρ _xyformula as follows:

In formula, X (n) is sample waveform data, and Y (n) is wave-recording sampling data;

Be averaging the related coefficient of each waveform, the maximum fault type of average correlation coefficient is the final result identified.

5. a kind of DC transmission engineering typical case transient fault according to claim 1 recognition methods, it is characterized in that, step (1) specifically comprises the steps:

Step 101: extract the electrode line of fault fluid parameter output and the data-signal of negative line;

Step 102: differentiate the very fault pole that there occurs phase shift locking or restart action.

6. according to claim 1 ?a kind of DC transmission engineering typical case transient fault recognition methods described in 5 any one; it is characterized in that, by RTDS emulation, consider that the electromagnetic transient simulation of working control protection feature or physical fault recorder data set up fault waveform Sample Storehouse.