CN104253418B - Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method - Google Patents

Abstract

The invention discloses Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method, it comprises the following steps: step 1: determine the existing dynamic segment definite value △ 1 of concrete DC engineering DC filter Unbalance Protection for High Voltage Capacitor, static section definite value △ 2 and time parameter TI; Step 2: obtain ∫ ITD/ITS is dropped to △ 1 time T3 by △ 2; Step 3: time T3 is multiplied by a safety factor K1 (K1 > 1) and obtains T4=T3*K1, this time T4 is the dynamic segment action delay meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship.The present invention determines according to the time parameter TI of existing dynamic segment definite value △ 1, static section definite value △ 2 and integration module INT the dynamic segment action delay T4 meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship, the dynamic segment misoperation caused because of unbalance protection dynamic segment, static section time delay mismate after avoiding ITD/ITS disturbance to disappear.

Description

Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method

Technical field

The present invention relates to direct current transportation Control protection technical field, specifically in a kind of DC filter Unbalance Protection for High Voltage Capacitor, particularly there is the time delay fitting method of dynamic segment and static section in disturbance situation in uneven angle value.

Background technology

Many employings three tuning DC filter or double tunning DC filter in DC engineering, as illustrated in fig. 1 and 2.Wherein, Fig. 1 shows three tuning DC filter, it the 3rd tuned cell comprising the first tuned cell be composed in series by high-voltage capacitor C1 and inductance L 1, the second tune unit composed in parallel by capacitor C2 and inductance L 2 and composed in parallel by capacitor C3 and inductance L 3, this first tuned cell, second tune unit, the 3rd tuned cell are connected successively, after series connection, the first tuned cell is connected to high voltage bus, and the 3rd tuned cell is connected to neutral bus.Fig. 2 shows double tunning DC filter, it comprises the first tuned cell be composed in series by high-voltage capacitor C1 and inductance L 1 and the second tune unit composed in parallel by capacitor C2 and inductance L 2, connect between this first tuned cell, second tune unit, after series connection, the first tuned cell is connected to high voltage bus, and second tune unit is connected to neutral bus.

DC filter Unbalance Protection for High Voltage Capacitor exits DC filter when high-voltage capacitor interior section capacity cell breaks down, and prevents fault from spreading, and capacitor avalanche breakdown occurs.As shown in Figure 3; Unbalance Protection for High Voltage Capacitor detects the total current ITS and unsymmetrical current (spill current) ITD that flow through capacitor two-arm; get 12 (600Hz) harmonic contents; C1 capacitor internal damaged condition is judged by calculating uneven angle value ITD/ITS; when detecting that uneven angle value exceedes definite value; judge that the inner imbalance fault of high-voltage capacitor occurs, unbalance protection action.

Existing DC filter Unbalance Protection for High Voltage Capacitor divides two sections: dynamic segment and static section.Concrete criterion as shown in appendix 1.

Subordinate list 1 DC filter Unbalance Protection for High Voltage Capacitor criterion

For DC filter Unbalance Protection for High Voltage Capacitor dynamic segment; as ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1; after delay time T1; still meet ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1; then DC filter Unbalance Protection for High Voltage Capacitor action; otherwise DC filter Unbalance Protection for High Voltage Capacitor is failure to actuate.Static section adopts similar processing mode.Wherein, DC filter Unbalance Protection for High Voltage Capacitor dynamic segment definite value △ 1, delay time T1, static section definite value △ 2, delay time T2 determine according to concrete DC engineering.In concrete DC engineering, they are set point.Usually, △ 1< △ 2, T1=T2.The integrated value ∫ ITD/ITS of uneven angle value and detailed principle are by the logic realization of Fig. 4.

Existing DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay coordinate unreasonable; when there is ITD/ITS and the ∫ ITD/ITS waveform shown in Fig. 5; unbalance protection dynamic segment is by misoperation, and the out of service or direct current of DC filter is stopped transport, and causes unnecessary loss.ITD/ITS and ∫ ITD/ITS wave characteristics shown in Fig. 5 is:

(1) when DC filter high-voltage capacitor non-faulting, ITD/ITS experiences the disturbance (left side in-800ms moment) of long period, and its size reaches 50%, direction have just have negative, being just many.The disturbance of ITD/ITS result in ∫ ITD/ITS and rises with certain speed, also reaches 50%.During ITD/ITS disturbance, unbalance protection dynamic segment, static section are failure to actuate.

(2) after ITD/ITS disturbance disappears (right side in-800ms moment); the value of ITD/ITS drops to close to 0; ∫ ITD/ITS starts to decline with certain speed; and in its decline process; ITD/ITS-∫ ITD/ITS<-△ 1 is met and continues the longer time; exceed existing unbalance protection dynamic segment delay time T1, thus cause the misoperation of unbalance protection dynamic segment.

Summary of the invention

For the problems referred to above; the object of the present invention is to provide a kind of Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method; it is by determining the delay time of the dynamic segment meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship, the dynamic segment misoperation caused because of unbalance protection dynamic segment, static section time delay mismate after avoiding ITD/ITS disturbance to disappear.

For realizing above object, this invention takes following technical scheme:

Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method, described high-voltage capacitor is DC filter high-voltage capacitor, and it comprises the following steps:

Step 1: the time parameter TI determining the existing dynamic segment definite value △ 1 of concrete DC engineering DC filter Unbalance Protection for High Voltage Capacitor, static section definite value △ 2 and integration module INT;

Step 2: the following relation according to ∫ ITD/ITS and ITD/ITS:

${(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_n={(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_{n-1}+\frac{\mathrm{TA}}{\mathrm{TI}}[{(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_n-{(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_{n-1}]$

Wherein, ITD/ITS is the uneven angle value of DC filter Unbalance Protection for High Voltage Capacitor actual measurement, (ITD/ITS) _nbe the uneven angle value of the n-th sampled point, TA is the Sampling interrupt time of integration module INT;

Before being located at certain moment, the value of ∫ ITD/ITS and ITD/ITS is △ 2,0 is changed to by △ 2 at this moment ITD/ITS, then according to the relational expression of ITD/ITS and ∫ ITD/ITS, ∫ ITD/ITS declines according to certain speed, obtains ∫ ITD/ITS is dropped to △ 1 time T3 by △ 2;

Step 3: time T3 is multiplied by a safety factor K1 and obtains T4=T3*K1, K1>1; For DC filter Unbalance Protection for High Voltage Capacitor dynamic segment, as ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1, after delay time T4, still meet ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1, then DC filter Unbalance Protection for High Voltage Capacitor dynamic segment action, otherwise DC filter Unbalance Protection for High Voltage Capacitor dynamic segment is failure to actuate;

This time T4 is the dynamic segment action delay meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship.

Unbalance Protection for High Voltage Capacitor static section delay time continues to use existing static section delay time T2.

Compared with prior art; beneficial effect of the present invention is: the time parameter TI according to the existing dynamic segment definite value △ 1 of concrete DC engineering DC filter Unbalance Protection for High Voltage Capacitor dynamic segment, static section definite value △ 2 and integration module INT determines the dynamic segment action delay T4 meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship, the dynamic segment misoperation caused because of unbalance protection dynamic segment, static section time delay mismate after avoiding ITD/ITS disturbance to disappear.

Accompanying drawing explanation

Fig. 1 is the circuit structure diagram of existing three tuning DC filter;

Fig. 2 is the circuit structure diagram of existing double tunning DC filter;

Fig. 3 is the circuit theory diagrams of existing DC filter Unbalance Protection for High Voltage Capacitor;

Fig. 4 is the detail logic diagram of existing DC filter Unbalance Protection for High Voltage Capacitor;

Fig. 5 is the record ripple figure (this DC engineering △ 1=42.8%, △ 2=67.9%, T1=T2=800ms, TI=15000ms, TA=1ms) of certain DC engineering DC filter Unbalance Protection for High Voltage Capacitor ITD/ITS, ∫ ITD/ITS amount;

Fig. 6 is for the DC engineering DC filter Unbalance Protection for High Voltage Capacitor shown in Fig. 5 is after ITD/ITS disturbance disappears, and ∫ ITD/ITS is with certain speed decline design sketch;

Fig. 7 disappears for disturbance when the DC engineering ∫ ITD/ITS shown in Fig. 5 reaches △ 2, and ITD/ITS becomes 0, ∫ ITD/ITS and drops to △ 1 required time from △ 2;

Fig. 8 is the flow chart of DC filter Unbalance Protection for High Voltage Capacitor dynamic segment of the present invention and static section time delay fitting method.

Embodiment

Below in conjunction with the drawings and specific embodiments, content of the present invention is described in further details.

Embodiment

Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method, be mainly used in the dynamic segment misoperation that DC filter Unbalance Protection for High Voltage Capacitor is avoided because unbalance protection dynamic segment, static section time delay mismate cause after uneven angle value disturbance disappears.Please refer to shown in Fig. 8, it specifically comprises the following steps:

Step S01: the time parameter TI determining the existing dynamic segment definite value △ 1 of concrete DC engineering DC filter Unbalance Protection for High Voltage Capacitor, static section definite value △ 2 and integration module INT.Integration module INT mainly carries out integral operation to uneven angle value, and in DC control defence program, the function of integration module INT is shown below:

$Y_n=Y_{n-1}+\frac{\mathrm{TA}}{\mathrm{TI}}{X}_n$

In DC filter Unbalance Protection for High Voltage Capacitor, the embody rule of INT module is shown below:

${(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_n={(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_{n-1}+\frac{\mathrm{TA}}{\mathrm{TI}}[{(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_n-{(\&Integral;\mathrm{ITD}/\mathrm{ITS})}_{n-1}]$

Wherein, (ITD/ITS) _nbe the uneven angle value of the n-th sampled point, TA is the Sampling interrupt time of integration module INT.

Step S02: judge whether DC filter Unbalance Protection for High Voltage Capacitor ITD/ITS experiences disturbance; if ITD/ITS experiences disturbance; then after ITD/ITS disturbance disappears (referring to ITD/ITS vanishing); ∫ ITD/ITS starts to decline, and determines that ∫ ITD/ITS drops to the time T3 of △ 1 by △ 2.

When Fig. 6 is shown as the time parameter TI=15000ms of integration module INT, after ITD/ITS becomes 0 (disturbance disappearance) from 1, the effect that ∫ ITD/ITS declines with certain speed.

Fig. 7 shows certain DC engineering (this DC engineering △ 1=42.8%, △ 2=67.9%, TI=15000ms, TA=1ms) ∫ ITD/ITS when reaching △ 2 ITD/ITS disturbance disappear, ITD/ITS becomes 0, ∫ ITD/ITS and drops to △ 1 required time 8000ms from △ 2.

Step S03: time T3 is multiplied by a safety factor K1 (K1>1), is met the dynamic segment action delay T4=T3*K1 of DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship.

Step S04: for DC filter Unbalance Protection for High Voltage Capacitor dynamic segment, judges ITD/ITS-∫ ITD/ITS> △ 1, time delay T4, or ITD/ITS-∫ ITD/ITS<-△ 1, and whether time delay T4 meets.

Step S05: as ITD/ITS-∫ ITD/ITS> △ 1; time delay T4; or ITD/ITS-∫ ITD/ITS<-△ 1; time delay T4; if when after time delay, ITD/ITS-∫ ITD/ITS is still greater than △ 1 or is less than-△ 1, the action of DC filter Unbalance Protection for High Voltage Capacitor dynamic segment.

Step S06: on the contrary after time delay T4 during △ 1-≤ITD/ITS-∫ ITD/ITS< △ 1, DC filter Unbalance Protection for High Voltage Capacitor dynamic segment is failure to actuate.

The above embodiment only have expressed one embodiment of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.

Claims (1)

1. Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay fitting method, described high-voltage capacitor is DC filter high-voltage capacitor, it is characterized in that, it comprises the following steps:

Step 1: the time parameter TI determining the existing dynamic segment definite value △ 1 of concrete DC engineering DC filter Unbalance Protection for High Voltage Capacitor, static section definite value △ 2 and integration module INT;

Step 2: the following relation according to ∫ ITD/ITS and ITD/ITS:

${(\&Integral;ITD/ITS)}_n={(\&Integral;ITD/ITS)}_{n-1}+\frac{TA}{TI}\&lsqb;{(ITD/ITS)}_n-{(\&Integral;ITD/ITS)}_{n-1}\&rsqb;$

Wherein, ITD/ITS is the uneven angle value of DC filter Unbalance Protection for High Voltage Capacitor actual measurement, (ITD/ITS) _nbe the uneven angle value of the n-th sampled point, TA is the Sampling interrupt time of integration module INT;

Before being located at certain moment, the integrated value ∫ ITD/ITS of uneven angle value and the value of uneven angle value ITD/ITS are static section definite value △ 2,0 is changed to by static section definite value △ 2 at this moment uneven angle value ITD/ITS, then according to the relational expression of the integrated value ∫ ITD/ITS of uneven angle value ITD/ITS and uneven angle value, the integrated value ∫ ITD/ITS of uneven angle value declines according to certain speed, and the integrated value ∫ ITD/ITS obtaining uneven angle value is dropped to the time T3 of dynamic segment definite value △ 1 by static section definite value △ 2;

Step 3: time T3 is multiplied by a safety factor K1 and obtains T4=T3*K1, K1>1; For DC filter Unbalance Protection for High Voltage Capacitor dynamic segment, as ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1, after delay time T4, still meet ITD/ITS-∫ ITD/ITS> △ 1 or ITD/ITS-∫ ITD/ITS<-△ 1, then DC filter Unbalance Protection for High Voltage Capacitor dynamic segment action, otherwise DC filter Unbalance Protection for High Voltage Capacitor dynamic segment is failure to actuate;

This time T4 is the dynamic segment action delay meeting DC filter Unbalance Protection for High Voltage Capacitor dynamic segment and static section time delay matching relationship.