CN104734352A - Loop closing operation control method for power distribution line - Google Patents

Abstract

The invention discloses a loop closing operation control method for a power distribution line. After a main station system judges that loop closing operation needs to be performed, a main station sends a loop closing instruction to an interconnection switch. After a feeder terminal corresponding to the interconnection switch receives the loop closing instruction sent by the main station, firstly, it is determined that the switch is the interconnection switch; then, an FTU of the interconnection switch and FTUs of adjacent switches are in peer-to-peer communication, voltage information of two adjacent switches is acquired, calculation is performed through information of two line voltages capable of being acquired, and another two line voltages of the interconnection switch are obtained; the voltage information on the two sides of the obtained interconnection switch is compared with a loop closing constant value, and whether a current system accords with a loop closing operation condition so that relevant operation can be performed is judged. According to the method, the loop closing condition is confirmed before the interconnection switch is turned on, loop closing correctness of loop closing operation of a power distribution network can be guaranteed, and the phenomenon that loop closing mistaken operation happens when the loop closing operation does not exist is prevented. A point-to-point peer-to-peer communication mode is adopted between terminals, communication time delay is short, and information transmission timeliness can be guaranteed.

Description

A kind of distribution line Loop Closing Operation control method

Technical field

The present invention relates to a kind of distribution line Loop Closing Operation control method.

Background technology

Along with the fast development of distribution network construction, China's power distribution network has basically formed the grid structure of " closed loop design, open loop operation ", and namely circuit can by multiple Power supply, and during normal operation, interconnection switch is in a point position, and interconnection switch both sides system separation runs.When needs fall load or line maintenance, first closed interconnection switch makes circuit cyclization, and then disconnects suitable block switch, has a power failure when partial line can be avoided short out, improves power supply reliability.The existing cyclization technology electrical network parameter that mainly main website uploads according to distribution terminal carries out computational analysis, judge whether system meets cyclization condition, if meet, send remote control close instruction to the line feed terminals (FTU) that interconnection switch is corresponding, line feed terminals controls interconnection switch and closes a floodgate after receiving instruction.But; communication delay is there is between main website and terminal; and the change of power distribution network operation conditions is very fast; when terminal receives the reclosing command of main website transmission; the operation conditions of system may there occurs change and not possess cyclization condition; if perform Loop Closing Operation according to instruction, then likely cause unmanageable network circulating power, cause the serious consequence such as protection act, device damage.Therefore be necessary, before control interconnection switch closes a floodgate, to detect current system operational factor by FTU, carry out judgement confirmation to Loop Closing Operation can be carried out.

When distribution line is built, feeder switch generally respectively configures a single-phase potential transformer (PT) in both sides, and detect AB voltage between phases and BC voltage between phases respectively, PT powers for FTU simultaneously, and its rated secondary voltage is 220V.So FTU can only collect each line voltage signal in switch both sides, and one be AB voltage between phases, another is BC voltage between phases, be difficult to judge whether to possess cyclization condition by these two voltages.In actual motion, any one feeder switch all may become interconnection switch, cannot be solved the problem of voltage signal deficiency by the method certain switch being increased to PT.

The FTU that interconnection switch is corresponding needs the information of voltage obtaining other switch places, could judge whether system possesses cyclization condition.Conventional electrical distribution automation mainly adopts point-to-multipoint communication mode, and namely main website communicates with all distribution terminals, and need between FTU through main website transfer ability exchange message, this mode speed is slow, time delay large, is difficult to the ageing of guarantee information.Novel Communication mode is point-to-point peer-to-peer communications, same Ethernet is accessed by line feed terminals, can direct exchange message between any two terminals, which does not need by main website transfer, avoids the problem that communications and data process time delay that main website centralized control brings is long.Peer-to-peer communications net can adopt fiber optic Ethernet network, and existing result of study shows, adopt connectionless transport layer User Datagram Protoco (UDP) (UDP) to transmit data, under suitable network traffics, the transmission delay of its reality can not more than 10ms.

Chinese patent ZL201210257852.X discloses a kind of closed-loop operational control method for power distribution network, can the voltage signal that line feed terminals gathers switch calculates judgement cyclization, and judged result is uploaded to distribution main website, main website uploads result when needs cyclization according to terminal and determines whether perform closing operation.Carried out the link of cyclization condition confirmation by line feed terminals before the not mentioned combined floodgate of the method, and its prerequisite realized is all voltage signals that terminal can collect needed for calculating, feeder switch both sides can not be adapted to and respectively only configure a voltage transformer, the actual conditions of voltage signal deficiency can be gathered.

Chinese patent 201310156849.3 discloses a kind of closed loop network and changes method for electrically, device and distribution terminal, cyclization condition judgment is carried out by station institute's terminal (DTU) before cyclization, the method controls for the bus Loop Closing Operation in switching station (switchyard), can not be used for the distribution line that terminal can gather voltage signal deficiency.

Summary of the invention

The present invention, in order to solve the problem, proposes a kind of distribution line Loop Closing Operation control method, by line feed terminals, the method confirms that before Loop Closing Operation interconnection switch two side system is in the state same period, avoids cyclization misoperation occurs.

To achieve these goals, the present invention adopts following technical scheme:

On feeder line, each terminal (comprising terminal RTU in station) realizes point-to-point communication by fiber optic Ethernet, peer switch information; Main website accesses peer-to-peer network by communication processor, with each terminal communication.

A kind of distribution line Loop Closing Operation control method, comprises the following steps:

(1) main website sends cyclization instruction to interconnection switch;

(2) first the FTU that interconnection switch is corresponding judges whether switch is interconnection switch after receiving the cyclization instruction of main website transmission; If interconnection switch, then continue to perform step (3), otherwise locking cyclization report main website;

(3) FTU of interconnection switch and the FTU peer-to-peer communications of adjacent two block switches, obtain the line information of voltage at adjacent two switch places, calculates, obtain two other line voltage at interconnection switch place in conjunction with self collectable two line information of voltage;

(4) comparing gathering with the interconnection switch both sides information of voltage calculated and cyclization definite value, judging whether current system meets Loop Closing Operation condition;

(5) if meet cyclization condition, perform described cyclization instruction and control interconnection switch combined floodgate, and report main website executed to close a floodgate; Otherwise locking Loop Closing Operation, and result is reported main website.

In described step (3), interconnection switch is designated as n, front and back two adjacent switch is designated as n-1 and n+1 respectively, and switch n-1 is positioned at interconnection switch M side, and switch n+1 is positioned at interconnection switch N side, assuming that switch M side PT accesses AB phase, N side PT accesses CB phase.

In described step (2), confirm that the condition of interconnection switch is that this switch is in a point position, and the voltage that switch both sides collect all is greater than and has compression set value, namely meets:

$\left\{\begin{array}{c}{U}_{M\·\mathrm{AB}}>U_T\\ U_{N\·\mathrm{CB}}>U_T\end{array}\right.$

Wherein U _mAB, U _nCBbe respectively interconnection switch M side AB phase top-stitching voltage magnitude and N side CB phase top-stitching voltage magnitude, U _tfor there being compression set value.

In described step (3), utilize adjacent switch line information of voltage to calculate two other line voltage of interconnection switch place, computing formula is:

$U_{M\·\mathrm{CB}}=U_{n-1\·\mathrm{CB}}\frac{U_{M\·\mathrm{AB}}}{U_{n-1\·\mathrm{AB}}}$

$U_{N\·\mathrm{AB}}=U_{n+1\·\mathrm{AB}}\frac{U_{N\·\mathrm{CB}}}{U_{n+1\·\mathrm{CB}}},$

Wherein U _mCB, U _nABbe respectively the alternate line voltage magnitude alternate with N side AB of interconnection switch M side CB, U _n-1ABand U _n-1CBthe line voltage at switch n-1 place, U _n+1ABand U _n+1CBthe line voltage at switch n+1 place.

In described step (4), interconnection switch two side line information of voltage and cyclization definite value compare, and judge whether to possess cyclization condition, particular content comprises:

A) interconnection switch two side line voltage magnitude all meets set point, namely meets:

U _min＜U _L＜U _max

Wherein U _lrepresent each line voltage at interconnection switch place, U _minfor lower magnitude limits definite value, U _maxfor limit value in amplitude;

B) the line voltage amplitude value difference that switch both sides are corresponding is all less than set point, namely meets:

$\left\{\begin{array}{c}|U_{M\&CenterDot;\mathrm{AB}}-U_{N\&CenterDot;\mathrm{AB}}|<U_{\mathrm{th}}\\ |U_{M\&CenterDot;\mathrm{CB}}-U_{N\&CenterDot;\mathrm{CB}}|<U_{\mathrm{th}}\end{array}\right.$

Wherein U _thfor difference in magnitude set point, generally 10V can be set as;

C) difference of two line voltage-phases of interconnection switch collection meets set point, namely meets:

Wherein, represent the phase angle of two line voltages, when two side systems run the complete same period, CB phase top-stitching voltage is 60 degree with the difference of AB phase top-stitching voltage-phase; for limit value under phase angle difference; for limit value on phase angle difference.

In described step (4), when three conditions of cyclization condition all meet, think that two side systems are in the state same period, allow interconnection switch to close a floodgate, perform Loop Closing Operation; Otherwise, forbid that interconnection switch closes a floodgate, cancel Loop Closing Operation.

In described step (4), circuit carry out overhauling or transfer load time, need grid switching operation, adopt the interconnection switch that first closes to make closing the ring, then disconnect the method for block switch.

Beneficial effect of the present invention is:

(1) adopt the interconnection switch that first closes to make closing the ring, then disconnect the method for block switch, certain customers' power cut problem in short-term that switch back brake can be avoided to cause, thus improve power supply reliability;

(2) the Loop Closing Operation control method that proposes of the present invention, judges two side systems whether same periods, to determine that the same period carries out Loop Closing Operation again, can effectively avoid cyclization misoperation occurs before cyclization;

(3) line feed terminals access ad hoc communications network, realize point-to-point communication by peer-to-peer communications net between each terminal, do not need by main website transfer, communication delay is little, ensure that the ageing of information transmission.

Accompanying drawing explanation

Fig. 1 is the flow chart of closed loop network control method of the present invention;

Fig. 2 is typical " handing in hand " skirt ceases to be busy line structure schematic diagram;

Fig. 3 is line feed terminals measurement voltage signal schematic diagram.

Wherein, PT is single-phase potential transformer, FTU is the terminal that feeder switch is corresponding, CB1, CB2 are outlet switch, S1-S7 is feeder switch, wherein S4 is interconnection switch, FTU1-FTU7 is respectively line feed terminals corresponding to each feeder switch, and RTU1, RTU2 are terminal in station that outlet switch is corresponding, and each FTU, RTU access ad hoc communications network.

Embodiment:

Below in conjunction with accompanying drawing and embodiment, the invention will be further described.

As shown in Figure 2, line feed terminals is distributed setting, and each line feed terminals is respectively used to the Measurement & Control of respective switch, and each line feed terminals (comprising terminal RTU in station) accesses ad hoc communications network, point-to-point exchange real time information; Main website accesses peer-to-peer network by communication processor, can communicate with any terminal.Power distribution network framework is " closed loop design, open loop operation ", " handing in hand " looped network of powering for Double-End Source, different according to ruuning situation, and arbitrary feeder switch all can be used as interconnection switch and uses.The S4 switch that FTU4 is corresponding is in fig. 2 interconnection switch, and during normal operation, S4 is in a point position, and system open loop runs.

When line maintenance or transfer load need grid switching operation, adopt the interconnection switch that first closes to disconnect the method for block switch again, the certain customers that switch back brake can be avoided to cause have a power failure in short-term.Such as the transformer of transformer station M transships, and plans switch S 2 downstream load to turn confession by transformer station N.The interconnection switch S4 if first cut-off switch S2 closes again, then can cause the user between S2 and S4 to have a power failure in short-term; The interconnection switch S4 that should first close makes circuit cyclization, then disconnect S2 realize turn confession, user can not be had in the process to have a power failure, improve power supply reliability.

The change of power distribution network operation conditions is very fast, owing to there is communication delay between main website and terminal, when terminal receives reclosing command, the operation conditions of system may there occurs change and not possess cyclization condition, even side circuit because of fault trip, if perform Loop Closing Operation, likely may lead to grave consequences.The present invention proposes before execution Loop Closing Operation, and judged both sides system running state by interconnection switch counterpart terminal, whether confirmation system possesses cyclization condition.

As shown in Figure 3, scene generally respectively configures a single-phase potential transformer (PT) in switch both sides, detects AB voltage between phases and BC voltage between phases respectively.So terminal FTU4 can only obtain the alternate line voltage U of transformer station M side AB in Fig. 2 _mABthe line voltage U alternate with transformer station N side BC _nBC, be difficult to judge whether to possess cyclization condition by these two information of voltage.The present invention proposes, and the terminal that interconnection switch is corresponding passes through ad hoc communications network, communicates with the line feed terminals of front and back two adjacent switch, obtains the information of voltage at adjacent switch place, both sides, judges in conjunction with its voltage information.As shown in Figure 2, FTU4 is communicated with FTU3, FTU5 by peer-to-peer network, and obtain the information of voltage at switch S 3, S5 place, wherein S3 place information of voltage is transformer station M side line voltage U _mABand U _mBC, S5 place information of voltage is transformer station N side line voltage U _nABand U _nBC.

As shown in Figure 1, be the key step that closed loop network control method that the present invention proposes comprises, composition graphs 2 pairs of key steps are described as follows:

After dispatcher or main station system judge to need to carry out Loop Closing Operation, send cyclization instruction by main website to the line feed terminals FTU4 that interconnection switch S4 is corresponding, this cyclization instruction is that instruction is closed in the remote control containing cyclization mark;

After FTU4 receives cyclization instruction, first confirm whether to inductive switch be interconnection switch; If interconnection switch then continues to perform step (3), otherwise locking cyclization report main website; Confirm that the condition of interconnection switch is that switch is in a point position, and the voltage that switch both sides collect all is greater than and has compression set value, namely meets

$\left\{\begin{array}{c}{U}_{M\&CenterDot;\mathrm{AB}}>U_T\\ U_{N\&CenterDot;\mathrm{CB}}>U_T\end{array}\right.$

Wherein U _mAB, U _nCBbe respectively interconnection switch M side AB phase top-stitching voltage magnitude and N side CB phase top-stitching voltage magnitude, U _tfor there being compression set value, 0.7 times of rated voltage generally can be set to;

FTU4 directly and FTU3 and FTU5 point-to-point communication, obtains the information of voltage at adjacent two switch S 3, S5 place, calculates, obtain two other line voltage of interconnection switch S4 place in conjunction with self collectable two line information of voltage; Computing formula is:

$U_{M\&CenterDot;\mathrm{CB}}=U_{S3\&CenterDot;\mathrm{CB}}\frac{U_{M\&CenterDot;\mathrm{AB}}}{U_{S3\&CenterDot;\mathrm{AB}}}$

$U_{N\&CenterDot;\mathrm{AB}}=U_{S5\&CenterDot;\mathrm{AB}}\frac{U_{N\&CenterDot;\mathrm{CB}}}{U_{S5\&CenterDot;\mathrm{CB}}}$

Wherein U _mCB, U _nABbe respectively the alternate line voltage magnitude alternate with N side AB of interconnection switch M side CB, U _s3ABand U _s3CBthe line voltage at switch S 3 place, U _s5ABand U _s5CBthe line voltage at switch S 5 place.

The information of voltage of interconnection switch S4 both sides and cyclization definite value are compared, judges whether current system possesses Loop Closing Operation condition; Criterion comprises: the difference that S4 two side line voltage magnitude all meets two line voltage-phases that the corresponding line voltage amplitude value difference in set point, S4 both sides is all less than set point, S4 gathers meets set point; When above-mentioned three conditions all meet, think that system is in the state same period, meet cyclization condition;

Three condition particular contents comprise:

1) interconnection switch two side line voltage magnitude all meets set point, namely meets:

U _min＜U _L＜U _max

Wherein U _lrepresent each line voltage at interconnection switch place, U _minfor lower magnitude limits definite value, generally can be set to 0.9 times of rated voltage, U _maxfor limit value in amplitude, generally can be set to 1.1 times of rated voltage;

2) the line voltage amplitude value difference that switch both sides are corresponding is all less than set point, namely meets:

$\left\{\begin{array}{c}|U_{M\&CenterDot;\mathrm{AB}}-U_{N\&CenterDot;\mathrm{AB}}|<U_{\mathrm{th}}\\ |U_{M\&CenterDot;\mathrm{CB}}-U_{N\&CenterDot;\mathrm{CB}}|<U_{\mathrm{th}}\end{array}\right.$

Wherein U _thfor difference in magnitude set point, generally 10V can be set as;

3) difference of two line voltage-phases of interconnection switch collection meets set point, namely meets:

Wherein, represent the phase angle of two line voltages, when two side systems run the complete same period, CB phase top-stitching voltage is 60 degree with the difference of AB phase top-stitching voltage-phase; for limit value under phase angle difference, generally 50 degree can be set to; for limit value on phase angle difference, generally 70 degree can be set to.

If meet cyclization condition, perform described cyclization instruction and control interconnection switch combined floodgate, and report main website executed to close a floodgate; Otherwise locking Loop Closing Operation, and result is reported main website.

When other feeder switches run as interconnection switch, be that the situation of interconnection switch is similar with S4, this is no longer going to repeat them.Same reason, the method that the present invention proposes also is applicable to other looped network forms, includes but not limited to the multi-joint network diagram of many segmentations, monocycle cable system, dicyclo cable system, many for a grid structure such as standby.

By reference to the accompanying drawings the specific embodiment of the present invention is described although above-mentioned; but not limiting the scope of the invention; one of ordinary skill in the art should be understood that; on the basis of technical scheme of the present invention, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection scope of the present invention.

Claims (7)

1. a distribution line Loop Closing Operation control method, is characterized in that: comprise the following steps:

(1) main website sends cyclization instruction to interconnection switch;

(2) first the FTU that interconnection switch is corresponding judges whether switch is interconnection switch after receiving the cyclization instruction of main website transmission; If interconnection switch, then continue to perform step (3), otherwise locking cyclization report main website;

(3) FTU of interconnection switch and the FTU peer-to-peer communications of adjacent two switches, obtain the line information of voltage at adjacent two switch places, calculates, obtain two other line voltage at interconnection switch place in conjunction with self collectable two line information of voltage;

(4) comparing gathering with the interconnection switch both sides information of voltage calculated and cyclization definite value, judging whether current system meets Loop Closing Operation condition;

(5) if meet cyclization condition, perform described cyclization instruction and control interconnection switch combined floodgate, and report main website executed to close a floodgate; Otherwise locking Loop Closing Operation, and result is reported main website.

2. a kind of distribution line Loop Closing Operation control method as claimed in claim 1, it is characterized in that: in described step (3), interconnection switch is designated as n, front and back two adjacent switches are designated as n-1 and n+1 respectively, and switch n-1 is positioned at interconnection switch M side, switch n+1 is positioned at interconnection switch N side, assuming that switch M side PT accesses AB phase, N side PT accesses CB phase.

3. a kind of distribution line Loop Closing Operation control method as claimed in claim 1, it is characterized in that: in described step (2), confirm that the condition of interconnection switch is that this switch is in a point position, and the voltage that switch both sides collect all is greater than and has compression set value, namely meets:

$\left\{\begin{array}{c}{U}_{M\&CenterDot;\mathrm{AB}}>U_T\\ U_{N\&CenterDot;\mathrm{CB}}>U_T\end{array}\right.$

Wherein U _mAB, U _nCBbe respectively interconnection switch M side AB phase top-stitching voltage magnitude and N side CB phase top-stitching voltage magnitude, U _tfor there being compression set value.

4. a kind of distribution line Loop Closing Operation control method as claimed in claim 1, is characterized in that: in described step (3), and utilize adjacent switch line information of voltage to calculate two other line voltage of interconnection switch place, computing formula is:

$U_{M\&CenterDot;\mathrm{CB}}=U_{n-1\&CenterDot;\mathrm{CB}}\frac{U_{M\&CenterDot;\mathrm{AB}}}{U_{n-1\&CenterDot;\mathrm{AB}}}$

$U_{N\&CenterDot;\mathrm{AB}}=U_{n+1\&CenterDot;\mathrm{AB}}\frac{U_{N\&CenterDot;\mathrm{CB}}}{U_{n+1\&CenterDot;\mathrm{CB}}}$

Wherein U _mCB, U _nABbe respectively the alternate line voltage magnitude alternate with N side AB of interconnection switch M side CB, U _n-1ABand U _n-1CBthe line voltage at switch n-1 place, U _n+1ABand U _n+1CBthe line voltage at switch n+1 place.

5. a kind of distribution line Loop Closing Operation control method as claimed in claim 1, is characterized in that: in described step (4), interconnection switch two side line information of voltage and cyclization definite value compare, and judge whether to possess cyclization condition, particular content comprises:

A) interconnection switch two side line voltage magnitude all meets set point, namely meets:

U _min＜U _L＜U _max

Wherein U _lrepresent each line voltage at interconnection switch place, U _minfor lower magnitude limits definite value, U _maxfor limit value in amplitude;

B) the line voltage amplitude value difference that switch both sides are corresponding is all less than set point, namely meets:

$\left\{\begin{array}{c}|U_{M\&CenterDot;\mathrm{AB}}-U_{N\&CenterDot;\mathrm{AB}}|<U_{\mathrm{th}}\\ |U_{M\&CenterDot;\mathrm{CB}}-U_{N\&CenterDot;\mathrm{CB}}|<U_{\mathrm{th}}\end{array}\right.$

Wherein U _thfor difference in magnitude set point, generally 10V can be set as;

C) difference of two line voltage-phases of interconnection switch collection meets set point, namely meets:

Wherein, represent the phase angle of two line voltages, when two side systems run the complete same period, CB phase top-stitching voltage is 60 degree with the difference of AB phase top-stitching voltage-phase; for limit value under phase angle difference; for limit value on phase angle difference.

6. a kind of distribution line Loop Closing Operation control method as claimed in claim 5, it is characterized in that: in described step (4), when three conditions of cyclization condition all meet, think that two side systems are in the state same period, permission interconnection switch closes a floodgate, and performs Loop Closing Operation; Otherwise, forbid that interconnection switch closes a floodgate, cancel Loop Closing Operation.

7. a kind of distribution line Loop Closing Operation control method as claimed in claim 6, it is characterized in that: in described step (4), circuit carry out overhauling or transfer load time, need grid switching operation, adopt the interconnection switch that first closes to make closing the ring, then disconnect the method for block switch.