CN110224491A - Monitoring device, monitoring method and the monitoring system of Distributed power net automatic switch - Google Patents

Abstract

The invention discloses a monitoring device for an automatic switch of a distributed distribution network. In addition to a circuit parameter acquisition circuit, a switching value input circuit, a communication interface, a control circuit, a relay output circuit, and a signal acquisition circuit connected to the circuit parameter acquisition circuit, the device In addition to the power supply and the controller respectively connected to the circuit parameter acquisition circuit, switch value input circuit, communication interface, control circuit, relay output circuit, signal acquisition circuit and device power supply, it also includes a power direction element and a first display device, wherein, The power direction element is set between the circuit parameter acquisition circuit and the controller, which can transmit the current direction information flowing through the local monitoring device to the controller, and the controller will display the current direction on the first display device, which is helpful for operation and maintenance Personnel locate fault points in a distributed distribution network. The invention also discloses a monitoring method and a monitoring system for an automatic switch of a distributed distribution network, which have the above beneficial effects.

Description

Monitoring device, monitoring method and monitoring system for automatic switch of distributed distribution network

technical field

The invention relates to the technical field of distribution network automation, in particular to a monitoring device, a monitoring method and a monitoring system for an automatic switch of a distributed distribution network.

Background technique

With the continuous development of distribution network automation technology and the improvement of users' requirements for power supply reliability, the construction and operation of distribution network automation is particularly important, laying the foundation for fault isolation and rapid restoration of power supply in non-faulty areas.

Feeder automation is an important part of distribution network automation. To realize feeder automation, a reasonable distribution network structure is required, and the conditions for ring network power supply are required; the operating mechanism of each ring network switch, load switch, and switch in the street distribution station must have remote operation functions; the ring network switch cabinet must have reliable The switch operation device power supply, the protection measurement and control unit (FTU), and the working device power supply for communication equipment; it has a reliable communication system that is not affected by the external environment. Under normal conditions, the feeder automation system monitors the status of the feeder section switch and tie switch as well as the feeder current and voltage in real time, and realizes remote or local closing and opening operations of the line switch. Obtain fault records at the time of failure, automatically identify and isolate the faulty section of the feeder, and quickly restore power to the non-faulty area. Among them, fault location, isolation and automatic recovery are of great significance to improve the reliability of power supply and shorten the power outage time in non-fault areas.

The existing fault removal logic is that the automatic switch itself detects a fault and starts logical judgment (the logic judgment time is recommended to be 2s). If there is a fault on its own and one side of the automatic switch on both sides has no fault signal, the fault point is located on the rear side, then Perform failover operations. The existing fault isolation logic is that the automatic switch itself has no faults, and when only one side of the automatic switches on both sides has a fault current, the fault is located on the front side, and the fault isolation operation is performed.

However, with the access of distributed power sources, the structure of the distribution network has been changed. The power points in the system are independent of each other, and the transition from a radial network to a network in which user loads are directly connected to distributed point power sources makes the fault location and processing process more complicated.

Fig. 1 is a schematic diagram of a "2-1" single ring network connection mode of a distributed distribution network; Fig. 2 is a schematic diagram of the action of an automatic switch of a distributed distribution network in the prior art. As shown in Figure 1, taking the "2-1" single-ring network wiring mode as an example, CB1 and CB2 are substation-side power supplies, FB1 is a distributed power supply, and K1 to K8, K21 to K26 are automatic switches. As shown in Figure 2, when the fault occurs between K4 and K5, since K1 to K5 all feel the fault current, according to the logic of slow-moving intelligent distribution, K5 should act to remove the fault, and K6 should act to isolate the fault. It is powered by K8 closing switch. However, due to the existence of the distributed power supply FB1, the current flow direction between K5 and K6 is different from the flow direction under the traditional distribution network, resulting in K4 and K5 getting the wrong fault point location or logic confusion, and the fault point location result cannot be obtained, resulting in The fault clearing and fault isolation operations for the application cannot be performed. And when the line fault trips, it is difficult for the operation and maintenance personnel to determine the location of the fault point.

How to enable operation and maintenance personnel to confirm the specific location of the fault point in the distributed power grid more conveniently, reduce the work pressure of the operation and maintenance personnel, and speed up the repair of distributed distribution network faults are technical problems that technicians in the field need to solve .

Contents of the invention

The purpose of the present invention is to provide a monitoring device, a monitoring method and a monitoring system for the automatic switch of a distributed distribution network, which are used to enable the operation and maintenance personnel to more conveniently confirm the specific location of the fault point in the distributed power grid, and reduce the burden of operation and maintenance. Reduce the work pressure of personnel and speed up the repair of faults in the distributed distribution network.

In order to solve the above technical problems, the present invention provides a monitoring device for an automatic switch of a distributed distribution network, including a circuit parameter acquisition circuit, a switch value input circuit, a communication interface, a control circuit, a relay output circuit, and the circuit parameter acquisition circuit The connected signal acquisition circuit, the device power supply, and the circuit parameter acquisition circuit, the switch value input circuit, the communication interface, the control circuit, the relay output circuit, the signal acquisition circuit and the A controller connected to the power supply of the device, the controller is used to control the control loop and the relay output circuit to perform protection actions according to the circuit parameters collected by the circuit parameter acquisition circuit and the switch signal input by the switch input circuit, Also includes:

The first input end is connected to the first relay connected to the protection current acquisition module in the circuit parameter acquisition circuit for collecting quick-break current, and the second input end is connected to the zero-sequence current acquisition in the circuit parameter acquisition circuit. The module is connected to the second relay for collecting zero-sequence current and overload value, the output terminal is connected to the power direction element of the controller, and the first display device is connected to the controller;

Wherein, the controller judges the direction of the current flowing through the local monitoring device according to the output value of the power direction element, and controls the first display device to display the direction of the current.

Optionally, the power directional element is specifically a rectifying power directional relay.

Optionally, the first display device is specifically a touch screen.

Optionally, it also includes a first indicator light circuit and a second indicator light circuit connected to the controller;

The controller controls the indicator light in the first indicator light circuit to light up when the current flowing through the monitoring device is a preset forward current and the forward current is greater than a first preset value;

The controller controls the indicator light in the second indicator light circuit to light up when the current flowing through the monitoring device is a preset reverse current and the reverse current is greater than a second preset value.

Optionally, it also includes a second display device connected to the controller for displaying status information of the automatic switch protected by the local monitoring device.

Optionally, a wireless communicator connected with the controller is also included.

Optionally, the wireless communicator is specifically a Wi-Fi communicator.

In order to solve the above technical problems, the present invention also provides a monitoring method for an automatic switch of a distributed distribution network, based on any one of the above-mentioned monitoring devices for an automatic switch of a distributed distribution network, including:

When the controller detects a fault in the main line of the distribution network, it analyzes the direction of the fault current of the local monitoring device, and exchanges detection information with the monitoring devices of the adjacent automatic switches on both sides;

When the controller analyzes and obtains that the fault current of the local monitoring device is a preset forward current, and there is a fault current on the automatic switch on only one side of the local monitoring device, the fault location is located at the rear side of said local monitoring device and controls the execution of fault clearing operations;

When the controller analyzes and obtains that the fault current of the local monitoring device is a preset reverse current, and there is a fault current on the automatic switch on only one side of the local monitoring device, locate the fault Click on the front side of the local monitoring device and perform fault isolation operations.

Optionally, also include:

The controller sends the direction of the fault current of the local monitoring device, the detection information of the adjacent automatic switch, the location result of the fault point and the result of executing the protection action to the remote dispatcher.

In order to solve the above technical problems, the present invention also provides a monitoring system for automatic switch of distributed distribution network, including the monitoring device for automatic switch of distributed distribution network described in any one of the above, and also includes:

The remote dispatching console communicated with the controller of the monitoring device is used to obtain and display the monitoring information of the monitoring device at the controller.

The monitoring device for the automatic switch of the distributed distribution network provided by the present invention, in addition to the circuit parameter acquisition circuit, the switching value input circuit, the communication interface, the control circuit, the relay output circuit, the signal acquisition circuit connected with the circuit parameter acquisition circuit, and the device power supply , and a controller connected to the circuit parameter acquisition circuit, switch value input circuit, communication interface, control circuit, relay output circuit, signal acquisition circuit and device power supply respectively, it also includes a power direction element and a first display device, wherein the power The first input end of the direction element is connected to the first relay used to collect the quick-break current of the protection current acquisition module in the circuit parameter acquisition circuit, and the second input end is connected to the zero-sequence current acquisition module in the circuit parameter acquisition circuit. The second relay used to collect zero-sequence current and overload value is connected, the output terminal is connected to the controller, the first display device is connected to the controller, and the controller judges the current flow through the local monitoring device according to the output value of the power direction element. direction, and control the first display device to display the direction of the current. By connecting the power direction element between the circuit parameter acquisition circuit and the controller, the direction of the current flowing through the local monitoring device is provided to the controller, and the controller controls and displays the direction of the current on the first display device, which is helpful for operation and maintenance The personnel can quickly and accurately locate the fault point in the distributed distribution network according to the direction of the current. Therefore, compared with the existing technology, the monitoring device can enable the operation and maintenance personnel to determine the specific location of the feeder fault point more conveniently. The work pressure of operation and maintenance personnel is reduced, and the repair of faults in the distributed distribution network is accelerated. The present invention also provides a monitoring method and monitoring system for an automatic switch of a distributed distribution network, which have the above-mentioned beneficial effects and will not be repeated here.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of a "2-1" single-ring network connection mode of a distributed distribution network;

Fig. 2 is a schematic diagram of the action of the automatic switch of the distributed distribution network in the prior art;

3 is a schematic structural diagram of a monitoring device for a distributed distribution network automatic switch provided by an embodiment of the present invention;

Figure 4(a) is a circuit diagram of a power directional element provided by an embodiment of the present invention;

Fig. 4 (b) is the circuit diagram of the actuator loop in the power direction element shown in Fig. 4 (a);

Fig. 4(c) is a schematic diagram of a 90° wiring method of a power directional element provided by an embodiment of the present invention;

5 is a schematic panel diagram of a monitoring device for a distributed distribution network automatic switch provided by an embodiment of the present invention;

FIG. 6 is a schematic panel diagram of another monitoring device for an automatic switch of a distributed distribution network provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of displaying the fault scenario shown in FIG. 2 according to the solution of the embodiment of the present invention.

Detailed ways

The core of the present invention is to provide a monitoring device, a monitoring method and a monitoring system for the automatic switch of a distributed distribution network, which are used to enable the operation and maintenance personnel to more conveniently confirm the specific location of the fault point in the distributed power grid, and reduce the burden of operation and maintenance. Reduce the work pressure of personnel and speed up the repair of faults in the distributed distribution network.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Fig. 3 is a schematic structural diagram of a monitoring device for a distributed distribution network automatic switch provided by an embodiment of the present invention; Fig. 4 (a) is a circuit diagram of a power direction element provided by an embodiment of the present invention; Fig. 4 (b) It is the circuit diagram of the actuator circuit in the power directional element shown in Fig. 4 (a); Fig. 4 (c) is the schematic diagram of the 90° wiring method of a kind of power directional element provided by the embodiment of the present invention; Fig. 5 is the schematic diagram of the present invention A schematic panel diagram of a monitoring device for a distributed distribution network automatic switch provided in the embodiment; FIG. 6 is a panel schematic diagram of another monitoring device for a distributed distribution network automatic switch provided in an embodiment of the present invention.

As shown in Figure 3, the monitoring device of the automatic switch of the distributed distribution network provided by the embodiment of the present invention includes a circuit parameter acquisition circuit, a switch value input circuit, a communication interface, a control circuit, a relay output circuit, and the circuit parameter acquisition circuit The connected signal acquisition circuit, the device power supply, and the controller connected to the circuit parameter acquisition circuit, switch value input circuit, communication interface, control circuit, relay output circuit, signal acquisition circuit and device power supply respectively, the controller is used to collect data according to the circuit parameters The circuit parameters collected by the circuit and the digital signal input by the digital input circuit control the control circuit and the relay output circuit to perform protection actions, including:

The first input end is connected to the first relay SJ connected to the protection current acquisition module in the circuit parameter acquisition circuit for collecting quick-break current, and the second input end is connected to the zero-sequence current acquisition module in the circuit parameter acquisition circuit. The second relay YJ for collecting zero-sequence current and overload value is connected, the output terminal is connected with the power direction element of the controller, and the first display device is connected with the controller;

Wherein, the controller judges the direction of the current flowing through the local monitoring device according to the output value of the power direction element, and controls the first display device to display the direction of the current.

In a specific implementation, the circuit parameter acquisition circuit includes a bus voltage acquisition module connected to the bus voltage YMc, YMb, and YMc, a measurement current acquisition module connected to the three-phase line, a protection current acquisition module, and a zero-sequence current acquisition module. The current device is connected to the protection current acquisition circuit, one end of the quick-break overcurrent device is connected to the first relay SJ, and the other end is connected to the second relay TJ, and the second relay TJ is also controlled by the remote jump signal.

The light input circuit includes remote control signal terminals, spring energy storage signal terminals, handcart work terminals, handcart test terminals, remote signal terminals 5~12, remote signal common terminals, etc., and remote control signal terminals, spring energy storage signal terminals , handcart working terminal, handcart test terminal, and remote signal terminals 5-12 are all connected to the positive pole of the 24V device power supply, and the remote signal common terminal is connected to the negative pole of the 24V device power supply.

The communication interface can adopt RS485 communication interface.

The control circuit includes control device power supply (+, -) terminals, trip input terminal, trip outlet terminal, closing input terminal, anti-jump push-out terminal, closing exit terminal, trip monitoring terminal, closing monitoring terminal, relay output circuit Including trip output terminal, closing output terminal and logic trip terminal.

Among them, the positive and negative poles of the power supply of the control device are respectively connected to the power supply terminals +KM and -KM of the device, and the trip input terminal, the trip outlet terminal and the two ends of the trip output terminal of the relay output circuit are all connected to the switch TQ. The circuit of the terminal also includes a hand trip switch to control the trip action; the closing input terminal, the closing exit terminal and the two ends of the closing terminal of the relay output circuit are all connected to the switch HQ, and at the same time, the closing input terminal The circuit of the terminal also includes a hand switch to control the closing action.

The signal acquisition circuit includes the accident signal (SJ) acquisition circuit, the forecast signal (YJ) acquisition circuit, the device failure (GZJ) acquisition circuit, the reset input (+, -) circuit, etc. In the accident signal (SJ) acquisition circuit, the forecast signal ( YJ) acquisition circuit and device failure (GZJ) acquisition circuit are also connected with circuits including signal power supply, single-phase electric energy meter (DD), and high-voltage circuit breaker (DL), as shown in Figure 1 for details.

The connection of the device power supply is shown in Figure 3.

In addition to the above elements, the monitoring device for the automatic switch of the distributed distribution network provided by the embodiment of the present invention also includes a power directional element and a first display device, and the controller judges the fault current flow through the local monitoring device through the output of the power directional element. The direction is used as the basis for locating the fault point. In the embodiment of the present invention, referring to the distributed distribution network feeder structure shown in FIG. 1 , the current flowing from the power source CB1 is taken as the forward current, and the current flowing to the power source CB1 is taken as the reverse current.

Power directional elements are also called power directional relays, which are mainly divided into two types: amplitude comparison type and phase comparison type according to the principle. Among them, the phase comparison class judges that the current is positive based on the fact that the current direction is bus → line and the voltage is higher than the ground. Otherwise, it means that the current is reverse.

The power directional element can be a rectifying power directional relay, and its structure is shown in Figure 4(a) and Figure 4(b), including a voltage forming circuit, a comparison circuit and an actuator, and the 90° wiring method is shown in Figure 4(c) As shown, that is, three-phase symmetry and power factor in the case of, advanced The wiring method, the parameters are shown in the table below:

Table 1 Parameter table of power direction components

Among them, the voltage forming circuit is composed of DKB and YB. Resistors R1 and R2 are used to eliminate creep and adjust balance. Capacitor C1 is used to form resonance with the excitation reactance of YB to make it lead 90°. Its memory function is used to eliminate dead zone. The memory time is tens of milliseconds. The comparison circuit is composed of a semiconductor rectifier bridge. The actuator is the polarized relay K _P , see mark "*", when the current flows in from the * terminal, the polarized relay K _P acts, otherwise it does not move.

phase voltage and phase current Converted by the converter to Then get the working voltage through series connection brake voltage After rectification, it enters the circulating current ratio circuit and is executed by the polarization relay K _P. The action equation of the polarized relay K _P is:

When this kind of power directional element is used to perform directional current protection of phase-to-phase short circuit (mainly three-phase symmetrical short-circuit protection in the positive direction), if the Based on For example, the phase-to-phase short-circuit protection range is [-α-90°, -α+90°], where α is the angle at which the voltage leads the current, generally 45°. but and The included angle is [-135°, 45°]. The principle of zero-sequence directional protection is similar to that of phase current directional protection. is the zero-sequence voltage U ₀ , is the zero-sequence current I ₀ , generally speaking, the zero-sequence current leads the zero-sequence voltage by 90° when the small-current grounding system is normal, and the zero-sequence voltage is 90° behind the zero-sequence current when the fault occurs, so its action range is generally [180°, 360° ]. When the large current grounding system fails, the zero-sequence current leads the zero-sequence voltage by 110°, and its action range is generally about [15°, 195°].

Then for the embodiment of the present invention, the power direction interval of the zero-sequence current (the angle between the zero-sequence current I ₀ and the zero-sequence voltage U ₀ ) is: [0°, 180°] dir=1, [180°, 360° °]dir=2; the phase-to-phase current takes a sensitive angle of 45°, and the power direction interval ( and and and ) is: [45°, 225°] dir=1, [225°, 45°] dir=2. Among them, dir=1, 2 indicates the direction of the flow, which is related to the installation direction of the current transformer. The general installation method is to use the busbar side of the ring main unit as the polarity end, and the other side as the non-polarity end.

Optionally, the first display device may use a touch screen.

As shown in Figure 5, the panel effect diagram of the monitoring device of the distributed distribution network automatic switch provided by the embodiment of the present invention is shown in Figure 5, except for the nameplate, used to display the A-phase current, B-phase current, and C-phase current Display window, voltage and current type selection knob, condensation controller, light switch, energy storage indicator light, position indicator light, close position indicator light, signal source selection knob (OK), opening and closing selection knob (1SA), Protection trip outlet pressure plate (LP1), protection closing outlet pressure plate (LP2), remote control opening outlet pressure plate (LP3), remote control closing outlet pressure plate (LP4), reclosing function input pressure plate (LP5), synchronous function input pressure plate (LP6 ), it also includes a first display device, in which words such as "forward fault current I≥828A" or "reverse fault current I≥828A" can be displayed.

Among them, the indicator lights of different functions are set to different colors, such as the energy storage indicator is set to yellow, the position indicator is set to green, and the position indicator is set to red; the pressure plates of different functions are set to different colors, such as the outlet pressure plate adopts Red, the functional pressure plate is yellow; the connection plate is screwed on the pressure plate, and the open end should be installed on the top.

Furthermore, each switch and knob should be equipped with a plastic cover to prevent accidental touch.

Optionally, the monitoring device for the automatic switch of the distributed distribution network may also include a first indicator circuit and a second indicator circuit connected to the controller;

The controller controls the indicator light L1 in the first indicator light circuit to light up when the current flowing through the monitoring device is a preset forward current and the forward current is greater than a first preset value;

The controller controls the indicator light L2 in the second indicator light circuit to light up when the current flowing through the monitoring device is a preset reverse current and the reverse current is greater than a second preset value.

The panel effect of the monitoring device with the addition of the first indicator light circuit and the second indicator light circuit is shown in Figure 6, and a forward fault current indicator light and a reverse fault current indicator light can be set side by side with other indicator lights.

Optionally, the monitoring device for the automatic switch of the distributed distribution network may further include a second display device connected to the controller for displaying status information of the automatic switch protected by the monitoring device. Among them, the status information of the automatic switch includes "fault removal success/failure", "fault isolation success/failure", "communication abnormality", "rejection" and so on.

In order to remind the operation and maintenance personnel more significantly, the monitoring device of the automatic switch of the distributed distribution network may also include a buzzer circuit connected to the controller;

The controller controls the buzzer in the buzzer circuit to give an alarm when the fault current flows through the local protection device.

The protection measurement and control unit provided by the embodiment of the present invention is fixed on the cabinet door of the secondary small room in an embedded installation mode, and is connected to the integrated measurement and control communication unit through Ethernet or RS485 bus, correspondingly, two or more RJ45s should be reserved in the integrated measurement and control communication unit Network Interface.

The message requirements of the protection measurement and control device provided by the embodiment of the present invention include:

Event sequence records should be classified into equipment failure sequence records and automation equipment failure sequence records;

The intelligent distributed signals received by the protection, measurement and control devices should be saved as SOE records, such as signals of fault current detected by adjacent switches, fault removal signals sent by adjacent switches, fault isolation signals sent by adjacent switches, adjacent switches The rejection signal sent, the communication failure signal of the switch, etc.;

Jitter signals should be filtered in sequence of events records.

The monitoring device for the automatic switch of the distributed distribution network provided by the present invention, in addition to the circuit parameter acquisition circuit, the switching value input circuit, the communication interface, the control circuit, the relay output circuit, the signal acquisition circuit connected with the circuit parameter acquisition circuit, and the device power supply , and a controller connected to the circuit parameter acquisition circuit, switch value input circuit, communication interface, control circuit, relay output circuit, signal acquisition circuit and device power supply respectively, it also includes a power direction element and a first display device, wherein the power The first input end of the direction element is connected to the first relay used to collect the quick-break current of the protection current acquisition module in the circuit parameter acquisition circuit, and the second input end is connected to the zero-sequence current acquisition module in the circuit parameter acquisition circuit. The second relay used to collect zero-sequence current and overload value is connected, the output terminal is connected to the controller, the first display device is connected to the controller, and the controller judges the current flow through the local monitoring device according to the output value of the power direction element. direction, and control the first display device to display the direction of the current. By connecting the power direction element between the circuit parameter acquisition circuit and the controller, the direction of the current flowing through the local monitoring device is provided to the controller, and the controller controls and displays the direction of the current on the first display device, which is helpful for operation and maintenance The personnel can quickly and accurately locate the fault point in the distributed distribution network according to the direction of the current. Therefore, compared with the existing technology, the monitoring device can enable the operation and maintenance personnel to determine the specific location of the feeder fault point more conveniently. The work pressure of operation and maintenance personnel is reduced, and the repair of faults in the distributed distribution network is accelerated.

On the basis of the above embodiments, in another embodiment, the monitoring device for the automatic switch of the distributed distribution network may further include a wireless communicator connected with the controller.

In a specific implementation, the wireless communicator may specifically use a Wi-Fi communicator or a GPRS communicator.

In addition, the monitoring device for the automatic switch of the distributed distribution network may also include a third indicator circuit, a fourth indicator circuit and a fifth indicator circuit connected to the controller;

The controller controls the indicator light in the third indicator circuit to light up when the corresponding automatic switch fails to remove the fault, controls the indicator light in the fourth indicator circuit to light up when the automatic switch fails to isolate the fault, and the automatic switch has communication abnormality When the indicator light in the fourth indicator light circuit is controlled to light up.

The various embodiments corresponding to the monitoring device for the automatic switch of the distributed distribution network are described in detail above. On this basis, the present invention also discloses a monitoring system for the automatic switch of the distributed distribution network including the above-mentioned device.

In addition to the monitoring device for the automatic switch of the distributed distribution network provided by the above embodiments, the monitoring system for the automatic switch of the distributed distribution network provided by the embodiment of the present invention also includes:

The remote dispatching console communicates with the controller of the monitoring device, and is used to obtain and display the monitoring information of the monitoring device at the controller.

The various embodiments corresponding to the monitoring device of the automatic switch of the distributed distribution network are described in detail above. On this basis, the present invention also discloses a monitoring method of the automatic switch of the distributed distribution network corresponding to the above-mentioned device.

Based on the monitoring device for the automatic switch of the distributed distribution network provided by the above-mentioned embodiments, the monitoring method for the automatic switch of the distributed distribution network includes:

When the controller detects a fault in the main line of the distribution network, it analyzes the direction of the fault current of the local monitoring device, and exchanges detection information with the monitoring devices of the adjacent automatic switches on both sides;

When the controller analyzes that the fault current of the local monitoring device is the preset forward current, and there is a fault current on only one automatic switch on both sides of the local monitoring device, locate the fault point at the rear side of the local monitoring device and control Execute fault removal operations;

When the controller analyzes that the fault current of the local monitoring device is the preset reverse current, and there is a fault current on only one automatic switch on both sides of the local monitoring device, locate the fault point on the front side of the local monitoring device and execute Fault isolation operation.

Further, the monitoring method of the automatic switch of the distributed distribution network may also include

The controller sends the direction of the fault current of the local monitoring device, the detection information of the adjacent automatic switch, the location result of the fault point and the result of executing the protection action to the remote dispatcher.

In the specific implementation, when the controller obtains the fault current flowing through the automatic switch corresponding to the local monitoring device by analyzing the circuit parameters, it starts a logical judgment, if its own fault current is positive, and there is a fault current flowing through the automatic switch on both sides When it is reversed, if the switch whose fault current is reversed is on its rear side, then locate the fault point on its rear side. If the outlet conditions such as "switch is in close position" and "voltage loss" are satisfied within the logic judgment time, then A trip command can be issued; wait for Tdz4 time (100ms is the switch action time), if there is no rejection, set the fault removal flag.

Or, self-detected faults start logic judgment, if the self-fault current is positive, and only one side of the automatic switch on both sides has fault current, then locate the fault point on its rear side, if within the logic judgment time satisfies the "switch in If there are exit conditions such as "closed position" and "loss of pressure", a trip command can be issued; wait for Tdz4 time (100ms is the switch action time), and if there is no rejection, set the fault removal flag.

If the fault current of itself is reversed (the forward direction is suitable for distribution networks without distributed power switches), and only one of the two sides has a fault current, locate the fault on its front side and start logical judgment; In the logical judgment time, when the switch is closed from pressure to no pressure, a trip command can be issued; wait for Tdz4 time (100ms is the switch action time), if there is no rejection, set the "fault isolation success" flag.

After fault removal or fault isolation is successful, the monitoring device sends a "fault removal" or "fault isolation success" signal to the master station; after fault isolation is successful, the monitoring device should also send a "fault isolation success" signal to the contact switch.

FIG. 7 is a schematic diagram of displaying the fault scenario shown in FIG. 2 according to the solution of the embodiment of the present invention.

As shown in Figure 7, applying the monitoring device and monitoring method of the automatic switch of the distributed distribution network according to the embodiment of the present invention, K4 itself detects a fault and starts logic judgment, and its own fault current is positive, and only the fault current on the side of K5 is present on both sides. If the switch is reversed and the fault current is reversed on its back side, the fault point is located on its back side, so it trips. If there is no refusal to move, the "fault removal successful" flag is set.

K5's own fault current is reverse, and only one side of K4 has fault current on both sides. The fault is located on its front side, trips, and if there is no refusal to operate, set the "fault isolation successful" flag.

At the same time, in the monitoring interface of the ring network diagram or single-line diagram of the dispatching station, the signs of displaying the forward fault current signal and the display of the reverse fault current signal are added to let the dispatcher know the flow direction of the fault current; "Successful isolation" automatic signal light plate, so that the fault point is clear at a glance. Provide a technical support for dispatchers and on-site operation and maintenance personnel to quickly locate faults, and facilitate the analysis of automation equipment actions after a fault occurs.

A monitoring device, a monitoring method and a monitoring system for an automatic switch of a distributed distribution network provided by the present invention have been introduced in detail above. Each embodiment in the description is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

It should also be noted that in this specification, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations There is no such actual relationship or order between the operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Claims (10)

1. A monitoring device for a distributed distribution network automatic switch, comprising a circuit parameter acquisition circuit, a switch input circuit, a communication interface, a control loop, a relay output circuit, a signal acquisition circuit connected to the circuit parameter acquisition circuit, and a device a power supply, and a controller respectively connected to the circuit parameter acquisition circuit, the switch value input circuit, the communication interface, the control loop, the relay output loop, the signal acquisition circuit and the device power supply, The controller is used to control the control loop and the relay output circuit to perform protection actions according to the circuit parameters collected by the circuit parameter collection circuit and the switch signal input by the switch input circuit, and it is characterized in that it also includes: The first input end is connected to the first relay connected to the protection current acquisition module in the circuit parameter acquisition circuit for collecting quick-break current, and the second input end is connected to the zero-sequence current acquisition in the circuit parameter acquisition circuit. The module is connected to the second relay for collecting zero-sequence current and overload value, the output terminal is connected to the power direction element of the controller, and the first display device is connected to the controller; Wherein, the controller judges the direction of the current flowing through the local monitoring device according to the output value of the power direction element, and controls the first display device to display the direction of the current. 2. The monitoring device according to claim 1, wherein the power directional element is specifically a rectifying power directional relay. 3. The monitoring device according to claim 1, wherein the first display device is specifically a touch screen. 4. The monitoring device according to claim 1, further comprising a first indicator light circuit and a second indicator light circuit connected to the controller; The controller controls the indicator light in the first indicator light circuit to light up when the current flowing through the monitoring device is a preset forward current and the forward current is greater than a first preset value; The controller controls the indicator light in the second indicator light circuit to light up when the current flowing through the monitoring device is a preset reverse current and the reverse current is greater than a second preset value. 5. The monitoring device according to claim 1, further comprising a second display device connected to the controller for displaying status information of the automatic switch protected by the local monitoring device. 6. The monitoring device according to claim 1, further comprising a wireless communicator connected with the controller. 7. The monitoring device according to claim 6, wherein the wireless communicator is specifically a Wi-Fi communicator. 8. A monitoring method for an automatic switch of a distributed distribution network, characterized in that, based on the monitoring device for an automatic switch of a distributed distribution network according to any one of claims 1 to 7, comprising: When the controller detects a fault in the main line of the distribution network, it analyzes the direction of the fault current of the local monitoring device, and exchanges detection information with the monitoring devices of the adjacent automatic switches on both sides; When the controller analyzes and obtains that the fault current of the local monitoring device is a preset forward current, and there is a fault current on the automatic switch on only one side of the local monitoring device, the fault location is located at the rear side of said local monitoring device and controls the execution of fault clearing operations; When the controller analyzes and obtains that the fault current of the local monitoring device is a preset reverse current, and there is a fault current on the automatic switch on only one side of the local monitoring device, locate the fault Click on the front side of the local monitoring device and perform fault isolation operations. 9. The monitoring method according to claim 8, further comprising: The controller sends the direction of the fault current of the local monitoring device, the detection information of the adjacent automatic switch, the location result of the fault point and the result of executing the protection action to the remote dispatcher. 10. A monitoring system for an automatic switch of a distributed distribution network, characterized in that it comprises the monitoring device for an automatic switch of a distributed distribution network according to any one of claims 1 to 7, further comprising: The remote dispatching console communicated with the controller of the monitoring device is used to obtain and display the monitoring information of the monitoring device at the controller.