Monitoring system of open zero sequence voltage loop

Abstract

The invention discloses a monitoring system of an open zero sequence voltage loop. A sub-monitoring module comprises a first voltage relay module, a second voltage relay module, a first fuse module and a second fuse module. The first voltage relay module is connected in series with the first fuse module and then is connected to the first end and the second end of a secondary opening triangular winding of the bus voltage transformer; the second voltage relay module is connected in series with the second fuse module and then is connected to the third end and the fourth end of the secondary opening triangular winding of the bus voltage transformer; the first voltage relay module and the second voltage relay module are connected with the measurement and control module. The first voltage relay module and the second voltage relay module are used for monitoring wiring conditions of corresponding zero sequence voltage loops and outputting feedback signals to the measurement and control module. According to the invention, under the condition that the zero-sequence voltage loop is broken, the state of the relay contact is changed, so that the broken line condition of the zero-sequence voltage loop can be accurately monitored and reflected in real time.

Description

Technical Field

[0001] The invention relates to the technical field of circuit monitoring, and in particular to a monitoring system for an open zero-sequence voltage loop. Background Art

[0002] In the power system, due to poor contact of the auxiliary contacts of the bus voltage transformer disconnector and the burning of the contacts of the zero-sequence voltage circuit switching relay of the voltage transformer PT parallel device, the secondary open delta winding of the bus voltage transformer contained in the zero-sequence voltage circuit is often disconnected. When the system is operating normally, there is no zero-sequence voltage in the zero-sequence voltage circuit, and its unbalanced voltage is very small, generally about 3-5V, which varies with the load. When the zero-sequence voltage circuit is broken, due to the influence of the induced voltage, the induced voltage value of the open delta winding when the zero-sequence voltage circuit is broken is similar to the voltage value on the secondary open delta winding of the bus voltage transformer during normal operation. Therefore, it is difficult to monitor the zero-sequence voltage circuit break in the presence of induced voltage. Summary of the invention

[0003] Based on this, it is necessary to propose a monitoring system for an open zero-sequence voltage circuit in order to solve the technical problem that the disconnection problem of the zero-sequence voltage circuit in the prior art is difficult to monitor.

[0004] A monitoring system for an open zero-sequence voltage loop, the monitoring system for an open zero-sequence voltage loop comprising a measurement and control module and at least one sub-monitoring module, different sub-monitoring modules are connected to and monitor a different zero-sequence voltage loop; each sub-monitoring module comprises a first voltage relay module, a second voltage relay module, a first fuse module and a second fuse module; each zero-sequence voltage loop comprises a secondary open delta winding of a bus voltage transformer;

[0005] The first voltage relay module is connected in series with the first fuse module and then connected to the first end and the second end of the secondary open triangle winding of the bus voltage transformer;

[0006] The second voltage relay module is connected in series with the second fuse module and then connected to the third end and the fourth end of the secondary open triangle winding of the bus voltage transformer;

[0007] The bus voltage transformer secondary open triangle winding comprises voltage transformer secondary windings YHA, YHB and YHC connected in series, and the first end, the second end, the third end and the fourth end of the bus voltage transformer secondary open triangle winding are different series connection points in the bus voltage transformer secondary open triangle winding;

[0008] The normally closed contacts of the first voltage relay module and the second voltage relay module are both connected to the measurement and control module;

[0009] The first voltage relay module and the second voltage relay module are both used to monitor the connection status of the corresponding zero-sequence voltage circuit, and output a feedback signal reflecting the actual connection status of the zero-sequence voltage circuit to the measurement and control module, wherein the actual connection status includes the presence of a broken wire and normal.

[0010] The monitoring system for an open zero-sequence voltage circuit provided by the present application utilizes a voltage relay module in a sub-monitoring module to connect to the zero-sequence voltage circuit. The integrity of the zero-sequence voltage circuit connection determines the withstand voltage of the voltage relay, which in turn affects the closing or opening of the contacts in the voltage relay. Based on this, when the zero-sequence voltage circuit is disconnected, the disconnection of the zero-sequence voltage circuit can be accurately and real-time reflected by changing the state of the relay contacts, solving the technical problem in the prior art that the disconnection of the zero-sequence voltage circuit is difficult to monitor due to the interference of induced electricity. The present application can timely discover and solve faults by real-time monitoring of the disconnection problem of the zero-sequence voltage circuit, and timely prevent the zero-sequence voltage circuit from damaging the power grid due to disconnection, effectively ensuring the safe operation of other equipment in the power grid. Moreover, the present application can monitor the disconnection of different zero-sequence voltage circuits through different sub-monitoring modules, and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0012] in:

[0013] Figure 1 It is a structural block diagram of a monitoring system for an open zero-sequence voltage loop in one embodiment;

[0014] Figure 2 A schematic diagram of the connection between a sub-monitoring module and a corresponding zero-sequence voltage circuit in one embodiment;

[0015] Figure 3 A schematic diagram of the wiring between a sub-monitoring module and a zero-sequence voltage circuit and a measurement and control module in an embodiment;

[0016] Figure 4 is a circuit diagram of a sub-monitoring module in one embodiment;

[0017] Figure 5 is a circuit diagram of a voltage monitoring module in one embodiment;

[0018] Figure 6 is a circuit diagram of a main control module in one embodiment;

[0019] Figure 7 is a schematic diagram of a zero-sequence voltage monitoring interface in one embodiment;

[0020] Figure 8 FIG. 4 is a circuit diagram of a power module in one embodiment. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The substation zero-sequence voltage is generated from the open end of the secondary open-delta winding of the busbar voltage transformer. When the system is operating normally, the vector sum of the three-phase voltage is zero, and there is no zero-sequence voltage at the open end of the secondary open-delta winding of the voltage transformer. When a ground fault occurs in the system, a zero-sequence voltage is generated at the open end of the secondary open-delta winding of the voltage transformer.

[0023] Due to poor contact of the PT (voltage transformer) isolating switch contacts, burnt contacts of the PT parallel device zero-sequence voltage circuit switching relay, loose terminal blocks and other reasons, the zero-sequence voltage circuit may be disconnected, and the relevant protection device cannot collect the zero-sequence voltage, affecting the protection device action logic and endangering the reliable operation of the power grid.

[0024] The company's countermeasures stipulate that the zero-sequence voltage circuit cannot be protected and controlled by an air switch to prevent the circuit breaker from being in the disconnected position during normal operation and the device from having any response. In the event of a fault, the relevant protection device cannot collect the zero-sequence voltage, affecting the action logic of the protection device: the zero-sequence voltage circuit is not protected by an air switch, and the zero-sequence voltage generated by a system fault is prone to burn out the voltage transformer PT parallel and the voltage switching device due to a zero-sequence national line short circuit.

[0025] Therefore, it is very necessary to monitor the zero-sequence voltage circuit for line breaks.

[0026] Based on this, the present application provides a monitoring system for an open zero-sequence voltage loop.

[0027] like Figure 1As shown, in one embodiment, a monitoring system for an open zero-sequence voltage loop is provided. The monitoring system for an open zero-sequence voltage loop includes at least one sub-monitoring module, and different sub-monitoring modules are connected to and monitor a different zero-sequence voltage loop; each sub-monitoring module includes a first voltage relay module, a second voltage relay module, a first fuse module, and a second fuse module; each zero-sequence voltage loop includes a secondary open delta winding of a bus voltage transformer;

[0028] The first voltage relay module is connected in series with the first fuse module and then connected to the first end and the second end of the secondary open triangle winding of the bus voltage transformer;

[0029] The second voltage relay module is connected in series with the second fuse module and then connected to the third end and the fourth end of the secondary open triangle winding of the bus voltage transformer;

[0030] The bus voltage transformer secondary open triangle winding comprises voltage transformer secondary windings YHA, YHB and YHC connected in series, and the first end, the second end, the third end and the fourth end of the bus voltage transformer secondary open triangle winding are different series connection points in the bus voltage transformer secondary open triangle winding;

[0031] The normally closed contacts of the first voltage relay module and the second voltage relay module are both connected to the measurement and control module;

[0032] The first voltage relay module and the second voltage relay module are both used to monitor the connection status of the corresponding zero-sequence voltage circuit, and output a feedback signal reflecting the actual connection status of the zero-sequence voltage circuit to the measurement and control module, wherein the actual connection status includes the presence of a broken wire and normal.

[0033] Specifically, the monitoring system of the open zero-sequence voltage loop includes at least one sub-monitoring module (eg, sub-monitoring modules 1-n), such as Figure 1 As shown, each sub-monitoring module is connected to a zero-sequence voltage loop, and different sub-monitoring modules (sub-monitoring modules 1-n) are connected to different zero-sequence voltage loops (zero-sequence voltage loops 1-n), which is equivalent to each sub-monitoring module monitoring a zero-sequence voltage loop. The sub-monitoring module is also connected to the measurement and control module.

[0034] Each zero-sequence voltage loop includes a bus voltage transformer secondary open delta winding, each bus voltage transformer secondary open delta winding includes voltage transformer secondary windings YHA, YHB and YHC, and the voltage transformer secondary windings YHA, YHB and YHC are connected in series. The first end, the second end, the third end and the fourth end of the bus voltage transformer secondary open delta winding are different series connection points in the bus voltage transformer secondary open delta winding.

[0035] In this embodiment, each sub-monitoring module is connected to the secondary open delta winding of the bus voltage transformer of the zero-sequence voltage loop under its jurisdiction to monitor whether the series connection points between the secondary windings of the voltage transformer are in poor contact and cause disconnection.

[0036] Figure 2 Schematic diagram of the connection between the sub-monitoring module and the corresponding zero-sequence voltage circuit in one embodiment; the connection method of each sub-monitoring module and the secondary open delta winding of the bus voltage transformer of the zero-sequence voltage circuit under its jurisdiction is as follows Figure 2 As shown:

[0037] The first end is the connection head end L630 of the secondary open triangle winding of the bus voltage transformer, and the second end is the head end da of the YHA winding in the secondary open triangle winding of the bus voltage transformer;

[0038] The third end is the connection tail end N600 of the secondary open delta winding of the bus voltage transformer, and the fourth end is the tail end dn of the YHC winding in the secondary open delta winding of the bus voltage transformer.

[0039] Right now, Figure 2 In the circuit, the coil of the first voltage relay module YJa is connected in series with the first fuse module RD1 and then connected in parallel to the circuit of the bus voltage transformer secondary open triangle winding connection head end L630 and the YHA head end da. The coil of the second voltage relay module YJb is connected in series with the second fuse module RD2 and then connected in parallel to the circuit of the bus voltage transformer secondary open triangle winding connection tail end N600 and the YHC tail end dn. The normally closed contacts (normally closed auxiliary contacts) of the YJa and YJb voltage relays are connected in parallel to the open-in signal circuit of the measurement and control module.

[0040] or,

[0041] The specific connection mode of each sub-monitoring module and the secondary open delta winding of the bus voltage transformer of the zero-sequence voltage circuit under its jurisdiction is as follows:

[0042] The first end is the connection head end L630 of the secondary open triangle winding of the bus voltage transformer, and the second end is the tail end dn of the YHB winding in the secondary open triangle winding of the bus voltage transformer;

[0043] The third end is the connection tail terminal N600 of the secondary open triangle winding of the bus voltage transformer, and the fourth end is the starting end da of the YHB winding in the secondary open triangle winding of the bus voltage transformer.

[0044] or,

[0045] The specific connection mode of each sub-monitoring module and the secondary open delta winding of the bus voltage transformer of the zero-sequence voltage circuit under its jurisdiction is as follows:

[0046] The first end is the connection head end L630 of the secondary open triangle winding of the bus voltage transformer, and the second end is the connection point between the tail end dn of the YHB winding and the head end da of the winding YHA in the secondary open triangle winding of the bus voltage transformer;

[0047] The third end is the connection tail end N600 of the secondary open triangle winding of the bus voltage transformer, and the fourth end is the connection point between the head end da of the YHB winding and the tail end dn of the winding YHC in the secondary open triangle winding of the bus voltage transformer.

[0048] Of course, the above access method is only an example, and this application does not limit the access method.

[0049] In a specific embodiment, when the system is operating normally, if the zero-sequence voltage circuit is intact, the voltage on the voltage relay in the voltage relay module YJa and YJb is about 100V, and the voltage relay is started. If the circuit ab is broken, the voltage borne by the voltage relay YJa will be less than the starting value, and the voltage borne by the voltage relay YJb will be greater than the starting value; if the circuit cd is broken, the voltage borne by the voltage relay YJb will be less than the starting value, and the voltage borne by the voltage relay YJa will be greater than the starting value; if the circuit bc is broken, the voltage borne by the voltage relays YJa and YJb will be less than the starting value; if the auxiliary contacts of the busbar voltage transformer disconnector are in poor contact, the contacts of the voltage switching relay of the PT parallel device are disconnected, and the series connection points of the voltage transformer secondary windings YHA, YHB, and YHC are in poor contact and disconnected, the voltage borne by at least one voltage relay YJa or YJb will be less than the starting value, and the voltage relay will not start, as shown in Table 1:

[0050] Table 1

[0051]

[0052] Figure 3 FIG. 1 is a wiring diagram of a sub-monitoring module, a zero-sequence voltage circuit and a measurement and control module in an embodiment; Figure 3 , XD_IN is connected to the normally closed contact 2 in the first voltage relay module, namely YJa1, and XD_IN is also connected to the normally closed contact 2 in the second voltage relay module, namely YJb1. XD_IN can be directly connected to the first voltage +XD, or, XD_IN is connected to the first voltage +XD through an electronic switch, and the electronic switch can control whether the voltage relay module has the function of +XD output.

[0053] According to the connection mode between the first voltage relay module and the second voltage relay module and the zero-sequence voltage loop, the first voltage relay module and the second voltage relay module respectively manage and monitor different associated lines in the same zero-sequence voltage loop.

[0054] When the system is normal, that is, there is no disconnection in the zero-sequence voltage circuit, the first voltage relay module YJa has voltage, that is, when it is greater than the starting voltage, the normally closed contact 2 (YJa1) opens (disconnects), and XD_OUT=0; when the system has problems, a disconnection occurs in the first associated line of the zero-sequence voltage circuit, then the first voltage relay module YJa has no voltage, that is, when it is less than the starting voltage, the normally closed contact 2 (YJa1) closes, and XD_OUT=XD_IN.

[0055] Similarly, when the system is normal, that is, the zero-sequence voltage circuit is not broken, the second voltage relay module YJb has voltage, that is, when it is greater than the starting voltage, the normally closed contact 2 (YJb1) opens (disconnects), and XD_OUT=0; when the system has problems, a break occurs in the second associated line of the zero-sequence voltage circuit, then the second voltage relay module YJb has no voltage, that is, when it is less than the starting voltage, the normally closed contact 2 (YJb1) closes, and XD_OUT=XD_IN.

[0056] Furthermore, since XD_IN is connected to the first voltage +XD, when a line break occurs, the measurement and control module can obtain a feedback signal indicating that a line break exists in the zero-sequence voltage circuit.

[0057] If the zero-sequence voltage loop is normal and there is no broken line, XD_OUT=0, and the measurement and control module can obtain a feedback signal indicating that the zero-sequence voltage loop is normal.

[0058] Alternatively, the measurement and control module only obtains a feedback signal indicating that there is a line break in the zero-sequence voltage circuit when the line is broken, and when there is no line break, the measurement and control module does not receive any feedback signal.

[0059] One end of the measurement and control module is connected to the XD_OUT signal, and the other end is connected to the -XD signal.

[0060] The measurement and control module can be an external circuit connected to the monitoring system of the open zero-sequence voltage loop, or a module included in the monitoring system of the open zero-sequence voltage loop. The measurement and control module can output the feedback signal to an external display or send it to a master station, etc.

[0061] The monitoring system for the open zero-sequence voltage loop provided in the present embodiment utilizes the voltage relay module in the sub-monitoring module to connect with the zero-sequence voltage loop. The integrity of the zero-sequence voltage loop connection determines the withstand voltage of the voltage relay, which in turn affects the closing or opening of the contacts in the voltage relay. Based on this, when the zero-sequence voltage loop is disconnected, the disconnection of the zero-sequence voltage loop can be accurately and real-time reflected by changing the state of the relay contacts, solving the technical problem in the prior art that the disconnection of the zero-sequence voltage loop is difficult to monitor due to the interference of induced electricity. The present embodiment can timely discover and solve the fault by real-time monitoring the disconnection problem of the zero-sequence voltage loop, and timely prevent the zero-sequence voltage loop from damaging the power grid due to disconnection, effectively ensuring the safe operation of other equipment in the power grid. Moreover, the present embodiment can monitor the disconnection of different zero-sequence voltage loops through different sub-monitoring modules, and is highly practical.

[0062] In one embodiment, each sub-monitoring module further includes an alarm module connected to the first voltage relay module and the second voltage relay module;

[0063] The first voltage relay module and the second voltage relay module are also used to control the corresponding alarm module to issue an alarm prompt when the actual wiring condition of the zero-sequence voltage circuit is a disconnection.

[0064] Specifically, the first voltage relay module is connected to the first alarm module, and the second voltage relay module is connected to the second alarm module. The first voltage relay module monitors whether the first associated line of the zero-sequence voltage loop is broken, and the second voltage relay module monitors whether the second associated line of the zero-sequence voltage loop is broken.

[0065] If the first associated line monitored by the first voltage relay module is disconnected, the first voltage relay controls the corresponding first alarm module to issue an alarm.

[0066] If the second associated line monitored by the second voltage relay module is disconnected, the second voltage relay controls the corresponding second alarm module to issue an alarm.

[0067] Figure 3 FIG. 1 is a wiring diagram of a sub-monitoring module, a zero-sequence voltage circuit and a measurement and control module in an embodiment; Figure 3 , POWERLED_IN is connected to the normally closed contact 1 in the first voltage relay module, POWERLED_IN is also connected to the normally closed contact 1 in the second voltage relay module, POWERLED_IN can be directly connected to the second voltage POWER_LED+, or, POWERLED_IN is connected to the first voltage POWER_LED+ through an electronic switch, and the electronic switch can control whether the voltage relay module has the function of controlling the alarm module to alarm.

[0068] Figure 3 The middle alarm module is alarm light 1 and alarm light 2. In other embodiments, the alarm module can also be a buzzer, a sounding device, a display screen, etc. This application does not limit the alarm module.

[0069] When the system is normal, that is, the zero-sequence voltage circuit is not broken, the first voltage relay module YJa has voltage, that is, when it is greater than the starting voltage, the normally closed contact 1 is opened (disconnected); when the system has problems, a break occurs in the first associated line of the zero-sequence voltage circuit, then the first voltage relay module YJa has no voltage, that is, when it is less than the starting voltage, the normally closed contact 1 is closed, so that POWERLED_IN is connected to the second voltage POWER_LED+. Since the other end of the alarm light 1 is connected to the negative voltage POWER_LED-, the alarm light 1 can sound an alarm.

[0070] Similarly, when the system is normal, that is, the zero-sequence voltage circuit is not broken, the second voltage relay module YJb has voltage, that is, when it is greater than the starting voltage, the normally closed contact 1 is opened (disconnected); when the system has a problem, a break occurs in the second associated line of the zero-sequence voltage circuit, then the second voltage relay module YJb has no voltage, that is, when it is less than the starting voltage, the normally closed contact 1 is closed, so that POWERLED_IN is connected to the second voltage POWER_LED+. Since the other end of the warning light 2 is connected to the negative voltage POWER_LED-, the warning light 2 can sound an alarm.

[0071] refer to Figure 2 and Figure 3 A sub-monitoring module is the smallest monitoring unit and has four connection ports, a, b, c, and d corresponding to Figure 2 There are four connection points in the middle, +XD and -XD are remote signal power input. For a sub-monitoring module, there are 6 connection lines, a, b, c, d corresponding to Figure 2 The four connection points of the middle triangle winding. +XD and -XD are connected to the remote signal power supply. The normally closed contacts 2 of the two relays are connected in parallel, and then connected to the measurement and control module. At this time, if there is a fault between AC, the alarm light 1 will light up, and the measurement and control module will send a fault signal to the main station.

[0072] When there is a fault between db, the alarm light 2 lights up and the measurement and control module sends a fault signal to the master station.

[0073] When there is a fault between bc, both alarm lights 1 and 2 light up, and the measurement and control module sends a fault signal to the master station.

[0074] This embodiment provides an alarm module to generate an alarm when a zero-sequence voltage circuit is disconnected, thereby providing an effective and timely reminder.

[0075] In one embodiment, the monitoring system of the open zero-sequence voltage loop further includes a main control module connected to each sub-monitoring module;

[0076] The main control module is used to receive and respond to the user's specified monitoring instructions and generate monitoring start instructions for the target sub-monitoring module;

[0077] The target sub-monitoring module is used to start and monitor the wiring status of the corresponding zero-sequence voltage circuit after receiving the monitoring start instruction.

[0078] Specifically, the sub-monitoring module is the smallest monitoring unit of the monitoring system of the open zero-sequence voltage loop, and each sub-monitoring module monitors one zero-sequence voltage loop. Therefore, the monitoring system of the open zero-sequence voltage loop can monitor one or more zero-sequence voltage loops.

[0079] In order to realize the selectivity of monitoring and targeted monitoring of certain zero-sequence voltage circuits, the monitoring system of the open zero-sequence voltage circuit of this embodiment is provided with a main control module, which can receive the user's designated monitoring instruction, and generate a monitoring start instruction according to the designated monitoring instruction, and use the monitoring start instruction to control the designated target sub-monitoring module to start the monitoring function. Other sub-monitoring modules that have not received the monitoring start instruction will not start the monitoring function temporarily.

[0080] Among them, the main control module can obtain the user's specified monitoring instructions through wireless communication, and can also receive the user's specified monitoring instructions through the instruction receiving module. The instruction receiving module is connected to the main control module. The instruction receiving module can be a part of the monitoring system of the open zero-sequence voltage circuit, or it can be an external device, such as a button, a key, a touch display, etc., and this application does not impose any restrictions on this.

[0081] In this embodiment, the main control module can control any sub-monitoring module to start the monitoring function, thereby realizing personalized and targeted monitoring.

[0082] In one embodiment, the first voltage relay module includes a first relay; the second voltage relay module includes a second relay;

[0083] The first contact of the first relay is connected to the second end of the secondary open triangle winding of the bus voltage transformer through a pin of the first wiring terminal, and the eighth contact of the first relay is connected to the first end of the secondary open triangle winding of the bus voltage transformer through the first fuse, the first protection resistor, and another pin of the first wiring terminal in sequence; the sixth contact of the first relay is connected to the first voltage, and the seventh contact of the first relay is connected to the measurement and control module;

[0084] The first relay is specifically used to connect the sixth contact and the seventh contact of the first relay if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop, and output the first voltage to the measurement and control module;

[0085] The first relay is specifically used to connect the sixth contact and the fifth contact of the first relay if there is no disconnection in the first associated line in the monitored zero-sequence voltage loop, so that the seventh contact of the first relay has no output;

[0086] The first contact of the second relay is connected to the fourth end of the secondary open delta winding of the bus voltage transformer through a pin of the second wiring terminal, and the eighth contact of the second relay is connected to the third end of the secondary open delta winding of the bus voltage transformer through the second fuse, the second protection resistor, and another pin of the second wiring terminal in sequence; the sixth contact of the second relay is connected to the first voltage, and the seventh contact of the second relay is connected to the measurement and control module;

[0087] The second relay is specifically used to connect the sixth contact and the seventh contact of the second relay if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop, and output the first voltage to the measurement and control module;

[0088] The second relay is specifically used to connect the sixth contact and the fifth contact of the second relay if there is no disconnection in the second associated line in the monitored zero-sequence voltage loop, so that the seventh contact of the second relay has no output.

[0089] Specifically, Figure 4 is a circuit diagram of a sub-monitoring module in an embodiment; Figure 4 , each sub-monitoring module includes two relays (two relays form a relay group).

[0090] The first voltage relay module includes a first relay U1 ; the second voltage relay module includes a second relay U7 .

[0091] The first contact of the first relay U1 (i.e., contact 1) is connected to the second end of the secondary open delta winding of the bus voltage transformer through the pin 3 of the first wiring terminal U60, and the eighth contact 8 of the first relay U1 (i.e., contact 8) is connected to the first end of the secondary open delta winding of the bus voltage transformer through the first fuse F1, the first protection resistor R227, and the pin 4 of the first wiring terminal U60 in sequence; the sixth contact of the first relay U1 (i.e., contact 6) is connected to the first voltage XD_IN (i.e., +XD), and the seventh contact of the first relay U1 (i.e., contact 7) is connected to the measurement and control module, and outputs a signal XD_OUT to the measurement and control module;

[0092] The first relay U1 is specifically used to connect the sixth contact (contact 6) and the seventh contact (contact 7) of the first relay U1 if the first associated line in the monitored zero-sequence voltage loop is broken, and output the first voltage XD_IN (i.e. +XD) to the measurement and control module;

[0093] The first relay U1 is specifically used to connect the sixth contact (contact 6) and the fifth contact (contact 5) of the first relay U1 if there is no disconnection in the first associated line in the monitored zero-sequence voltage loop, so that the seventh contact (contact 7) of the first relay U1 has no output, that is, XD_OUT is a null signal;

[0094] In this embodiment, the first relay U1 and the second relay U7 share the same wiring terminal, that is, the first wiring terminal and the second wiring terminal are the same wiring terminal U60.

[0095] The first contact (contact 1) of the second relay U7 is connected to the fourth end of the secondary open delta winding of the bus voltage transformer through the pin 1 of the second wiring terminal U60, and the eighth contact (contact 8) of the second relay U7 is connected to the third end of the secondary open delta winding of the bus voltage transformer through the second fuse F7, the second protection resistor R228, and the pin 2 of the second wiring terminal U60 in sequence; the sixth contact (contact 6) of the second relay U7 is connected to the first voltage XD_IN (i.e. +XD), and the seventh contact (contact 7) of the second relay U7 is connected to the measurement and control module, and outputs a signal XD_OUT to the measurement and control module;

[0096] The second relay U7 is specifically used to connect the sixth contact and the seventh contact of the second relay U7 if the first associated line in the monitored zero-sequence voltage loop is broken, and output the first voltage XD_IN (i.e. +XD) to the measurement and control module;

[0097] The second relay U7 is specifically used to connect the sixth contact and the fifth contact of the second relay U7 if there is no break in the second associated line in the monitored zero-sequence voltage loop, so that the seventh contact of the second relay U7 has no output, that is, XD_OUT is a null signal.

[0098] It should be noted that XD_OUT output by the first relay U1 and XD_OUT output by the second relay U7 are two independent outputs, which are different feedback signals.

[0099] This embodiment can conveniently monitor whether the zero-sequence voltage circuit is broken through two relays, and respond in time to give a feedback signal.

[0100] In one embodiment, the third contact of the first relay is connected to the second voltage; the second contact of the first relay is connected to the first alarm module through the first alarm resistor and the third terminal;

[0101] The first relay is further used to connect the third contact of the first relay with the second contact if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop, so as to trigger the first alarm module to alarm;

[0102] The third contact of the second relay is connected to the second voltage; the second contact of the second relay is connected to the second alarm module through the second alarm resistor and the fourth terminal;

[0103] The second relay is also used to connect the third contact of the second relay with the second contact if there is a break in the second associated line in the monitored zero-sequence voltage loop, so as to trigger the second alarm module to alarm.

[0104] Specifically, Figure 4 is a circuit diagram of a sub-monitoring module in an embodiment; Figure 4 , the third contact (contact 3) of the first relay U1 is connected to the second voltage LED3.3V; the second contact (contact 2) of the first relay U1 is connected to the first alarm module through the first alarm resistor R161 and the pin 1 of the third wiring terminal H1; the pin 2 of the third wiring terminal H1 is grounded. The third wiring terminal H1 is connected to the first alarm module.

[0105] The third terminal H1 may be, for example, a B-2100S02P-A110 terminal.

[0106] The first relay U1 is further used to connect the third contact (contact 3) and the second contact (contact 2) of the first relay U1 if the first associated line in the monitored zero-sequence voltage loop is broken, so as to trigger the first alarm module to alarm;

[0107] The third contact (contact 3) of the second relay U7 is connected to the second voltage LED3.3V; the second contact (contact 2) of the second relay U7 is connected to the second alarm module through the second alarm resistor R166 and the pin 1 of the fourth terminal H19; the pin 2 of the fourth terminal H19 is grounded. The fourth terminal H19 is connected to the second alarm module.

[0108] The second relay U7 is also used to connect the third contact (contact 3) and the second contact (contact 2) of the second relay U7 if the second associated line in the monitored zero-sequence voltage circuit is broken, so as to trigger the second alarm module to alarm.

[0109] The first relay U1 is also used to connect the third contact and the fourth contact of the first relay U1 if there is no disconnection in the first associated line in the monitored zero-sequence voltage loop, so as to prevent the first alarm module from sounding an alarm.

[0110] The second relay U7 is also used to connect the third contact and the fourth contact of the second relay U7 if there is no disconnection in the second associated line in the monitored zero-sequence voltage loop, so as to prevent the second alarm module from sounding an alarm.

[0111] This embodiment adds an alarm module and uses a relay to control the alarm module to give an alarm when a line is disconnected, thereby achieving an effective alarm prompt.

[0112] In one embodiment, each sub-monitoring module further includes a first monitoring start module;

[0113] The first monitoring start module is used to connect the first voltage to the sixth contact of the first relay and the sixth contact of the second relay if a first monitoring start instruction is received.

[0114] Specifically, Figure 4 is a circuit diagram of a sub-monitoring module in an embodiment; Figure 4 , the first monitoring start module includes a switch control unit K1, a switch tube Q1, a resistor R185, a resistor R186 and a diode D2; the first end of the switch tube Q1 can obtain the first monitoring start instruction RELAY_EN1 through the resistor R186, for example, the first end of the switch tube Q1 is connected to the main control module through the resistor R186, and the main control module sends the first monitoring start instruction RELAY_EN1. The second end of the switch tube Q1 is grounded, the third end of the switch tube Q1 is connected to the voltage 24V through the resistor R185 and the diode D2, the third end of the switch tube Q1 is also connected to the voltage 24V through the resistor R185, the pin 6 of the switch control unit K1, and the pin 1, the pin 2 of the switch control unit K1 is connected to the first voltage XD_IN, and the pin 3 of the switch control unit K1 is respectively connected to the contact 6 of the first relay U1 and the contact 6 of the second relay U7.

[0115] The switch tube Q1 may be a triode or a MOS tube. If the switch tube Q1 is a triode, the first end of the switch tube Q1 is the base, the second end is the emitter, and the third end is the collector.

[0116] If the switch tube Q1 receives the first monitoring start instruction RELAY_EN1, the switch tube Q1 is turned on, and the switch control unit K1 connects pin 2 to pin 3, thereby connecting the first voltage XD_IN to the sixth contact of the first relay U1 and the sixth contact of the second relay U2. Thus, the sub-monitoring module where the first relay U1 and the second relay U2 are located starts to work, monitoring whether the corresponding zero-sequence voltage circuit is disconnected, that is, it has the function of outputting XD_OUT.

[0117] If the first monitoring start instruction RELAY_EN1 is not received or the first monitoring start instruction RELAY_EN1 is a low voltage and cannot turn on Q1, the first voltage XD_IN is disconnected from the sixth contact of the first relay and the sixth contact of the second relay, so that the first relay U1 and the second relay U2 cannot monitor the zero-sequence voltage loop, that is, the corresponding sub-monitoring module stops the monitoring function.

[0118] In addition, a wiring terminal U58 can also be set, and pin 1 of the wiring terminal U58 is connected to the first voltage XD_IN and pin 2 of the switch control unit K1, so as to connect the first voltage XD_IN to pin 2 of the switch control unit K1, and pin 2 of the wiring terminal U58 is connected to pin 7 of the relay and the measurement and control module, so as to output the output XD_OUT of pin 7 of the relay to the measurement and control module.

[0119] In this embodiment, by setting the first monitoring start module, it is possible to control whether any one or more sub-monitoring modules start the monitoring function.

[0120] In one embodiment, each sub-monitoring module further includes a second monitoring startup module;

[0121] The second monitoring start module is used for connecting the second voltage to the third contact of the first relay and the third contact of the second relay if a second monitoring start instruction is received.

[0122] Specifically, Figure 4 is a circuit diagram of a sub-monitoring module in an embodiment; Figure 4 The second monitoring start-up module includes a switch control unit K1, a switch tube Q1, a resistor R185, a resistor R186 and a diode D2; the first end of the switch tube Q1 can obtain the second monitoring start-up instruction RELAY_EN1 through the resistor R186. For example, the first end of the switch tube Q1 is connected to the main control module through the resistor R186, and the main control module sends the second monitoring start-up instruction RELAY_EN1. The second end of the switch tube Q1 is grounded, the third end of the switch tube Q1 is connected to the voltage 24V through the resistor R185 and the diode D2, and the third end of the switch tube Q1 is also connected to the voltage 24V through the resistor R185, the pin 6 of the switch control unit K1, and the pin 1, the pin 5 of the switch control unit K1 is connected to the second voltage LED3.3V, and the pin 4 of the switch control unit K1 is respectively connected to the contact 3 of the first relay U1 and the contact 3 of the second relay U7.

[0123] The switch tube Q1 may be a triode or a MOS tube. If the switch tube Q1 is a triode, the first end of the switch tube Q1 is the base, the second end is the emitter, and the third end is the collector.

[0124] If the switch tube Q1 receives the second monitoring start instruction RELAY_EN1, the switch tube Q1 is turned on, and the switch control unit K1 connects pin 5 to pin 4, thereby connecting the second voltage LED3.3V to the third contact of the first relay U1 and the third contact of the second relay U2. In this way, the sub-monitoring module where the first relay U1 and the second relay U2 are located can control whether the alarm module alarms, that is, it has an alarm function.

[0125] If the second monitoring start instruction RELAY_EN1 is not received or the second monitoring start instruction RELAY_EN1 is a low voltage and cannot turn on Q1, the second voltage LED3.3V is disconnected from the third contact of the first relay and the third contact of the second relay, so that the first relay U1 and the second relay U2 cannot control the alarm module to alarm, that is, the corresponding sub-monitoring module stops the alarm function.

[0126] It should be noted that the first monitoring startup module and the second monitoring startup module can be the same monitoring module. Figure 4 Pins 2 and 3 of the switch control unit K1 can control whether the first voltage XD_IN is connected, and pins 4 and 5 of the switch control unit K1 can control whether the second voltage LED3.3V is connected.

[0127] Figure 4 The first voltage XD_IN in is Figure 3 The voltage in is +XD, that is, after the switch is closed, XD_IN is the voltage +XD.

[0128] Figure 4 The second voltage LED3.3V is Figure 3 The voltage POWER_LED+ in the switch is POWER_LED+. After the switch is closed, POWERLED_IN is the voltage POWER_LED+.

[0129] In this embodiment, by setting the second monitoring start module, it is possible to control whether any one or more sub-monitoring modules start the alarm function.

[0130] In summary, Figure 4 U60 is the secondary open triangle winding terminal of the 110kV bus voltage transformer, U1 and U7 are voltage relays. When the system is working normally, the relay coil is energized, the normally open node is closed, and the normally closed contact is opened. When any section is disconnected, the relay coil loses power, the normally open contact is disconnected, and the normally closed contact is closed. The remote signal power supply is connected to the measurement and control module through the normally closed contact of the relay, and the measurement and control module sends a fault signal to the master station. The switch control unit K1 is a signal relay, which controls whether relays U1 and U7 have an alarm function by controlling the conduction and shutdown of the transistor Q1. In this device, there are 6 groups of AC100V relay groups and AC33.3V relay groups, and the K1 relay can prevent unused relays from issuing alarms. H1 and H19 are connected to alarm lights, which light up and alarm when the corresponding line is short-circuited. 110_N1, 110_N2, 110_P1, and 110_P2 are voltage monitoring points, which monitor the voltage on the voltage relay coil and display it on the LCD screen.

[0131] In one embodiment, the monitoring system of the open zero-sequence voltage loop further includes a main control module and a voltage monitoring module electrically connected, wherein different sub-monitoring modules correspond to different voltage monitoring modules;

[0132] The main control module is used to monitor the voltage between the first contact and the eighth contact of the first relay through the voltage monitoring module, and / or monitor the voltage between the first contact and the eighth contact of the second relay.

[0133] Specifically, Figure 4 is a circuit diagram of a sub-monitoring module in an embodiment; Figure 4 , the main control module is used to monitor the voltage between the first contact and the eighth contact of the first relay U1, that is, Figure 4 The potential 110_N1 of the first contact of the first relay U1 and the potential 110_P1 of the eighth contact of the first relay U1 are included in the figure.

[0134] and / or,

[0135] The main control module is also used to monitor the voltage between the first contact and the eighth contact of the second relay U7, that is, Figure 4 The potential 110_N2 of the first contact of the second relay U7 and the potential 110_P2 of the eighth contact of the first relay U1.

[0136] Figure 5 is a circuit diagram of a voltage monitoring module in an embodiment; Figure 5 The voltage monitoring module includes two sub-voltage monitoring modules; the first sub-voltage monitoring module is used to monitor the potential 110_N1 of the first contact of the first relay U1 and the potential 110_P1 of the eighth contact of the first relay U1, and the second sub-voltage monitoring module is used to monitor the potential 110_N2 of the first contact of the second relay U7 and the potential 110_P2 of the eighth contact of the first relay U1.

[0137] Pin 1 of chip U28 of the first sub-voltage monitoring module is connected to voltage 110_3.3V, and pin 1 of chip U28 is also grounded through capacitor C42. Pin 2 and pin 3 are connected to both ends of resistor R31, and pin 2 is also connected to the eighth contact of the first relay U1 through resistor R78 to obtain potential 110_P1, and pin 3 is also connected to the first contact of the first relay U1 through resistor R79 to obtain potential 110_N1. Pin 4 of chip U28 is grounded. Pin 8 of chip U28 is connected to voltage GL13.3V, and pin 8 of chip U28 is also grounded GND through capacitor C43. Pin 7 of chip U28 is connected to the main control module through resistor R32, and outputs signal AD110_1 to the main control module. Pin 7 of chip U28 is also grounded through resistor R32 and capacitor C44, and pin 6 and pin 5 of chip U28 are grounded.

[0138] Pin 1 of chip U35 of the second sub-voltage monitoring module is connected to voltage 110_3.3V, and pin 1 of chip U35 is also grounded through capacitor C45. Pin 2 and pin 3 are connected to both ends of resistor R35, and pin 2 is also connected to the eighth contact of the second relay U7 through resistor R80 to obtain potential 110_P2, and pin 3 is also connected to the first contact of the second relay U7 through resistor R81 to obtain potential 110_N2. Pin 4 of chip U35 is grounded. Pin 8 of chip U35 is connected to voltage GL13.3V, and pin 8 of chip U35 is also grounded GND through capacitor C46. Pin 7 of chip U35 is connected to the main control module through resistor R36, and outputs signal AD110_2 to the main control module. Pin 7 of chip U35 is also grounded through resistor R36 and capacitor C47, and pin 6 and pin 5 of chip U35 are grounded.

[0139] Both the first sub-voltage monitoring module and the second sub-voltage monitoring module first use some resistors to divide the measured voltage, and then use the isolation operational amplifier (U35, U28) to isolate the voltage, and then use the main control chip of the main control module, such as the ADC (Analog-to-Digital Converter) of the MCU to detect the voltage value.

[0140] Figure 6 is a circuit diagram of a main control module in an embodiment; Figure 6 Pins 93, 92, 91, 90, 89, 88, 51, 52, 53, 54, 55, and 56 of the main control chip U77 are respectively connected to the switch tubes Q1 of 12 different sub-monitoring modules to provide monitoring start instructions RELAY_EN1-RELAY_EN12 respectively.

[0141] The pins 23-26, 29-32, 35-36, and 15-16 of the main control chip U77 are respectively connected to the output ends of 12 different voltage monitoring modules to receive signals AD110_1 to AD110_12 respectively. Each sub-monitoring module corresponds to a voltage monitoring module.

[0142] Pins 68 and 69 of the main control chip U77 are connected to the serial port screen through the terminal U76, pin 4 of the terminal U76 is grounded, and pin 3 is connected to the voltage VCC.

[0143] The pins 72 and 76 of the main control chip U77 are connected to the clock signal CLK and the signal DIO through the connection terminal H13. The pin 14 of the main control chip U77 is connected to the reset signal RST through the connection terminal H13.

[0144] One end of the resistor R15 is connected to a voltage of 3.3V, and the other end is grounded via a capacitor C18. Both ends of the capacitor C18 are connected to a switch SW1. A reset signal RST can be generated via the switch SW1.

[0145] Pins 12 and 13 of the main control chip U77 are connected to the crystal oscillator circuit to obtain signals OSC_IN and OSC_OUT. One end of the crystal oscillator X1 is grounded through capacitor C120 and outputs signal OSC_IN, and the other end of the crystal oscillator X1 is grounded through capacitor C121 and outputs signal OSC_OUT.

[0146] The input voltage AV33 is connected to the ground AGND through the parallel capacitors C124 and C123. The input voltage AV33 is also connected to the ground after passing through the parallel capacitors C124 and C123 and the resistor R152. The input voltage AV33 also obtains a voltage of 3.3V through the inductor L4.

[0147] Pin 20 of the main control chip U77 is grounded to AGND, pins 99, 74, 27, and 10 of the main control chip U77 are grounded to GND, pins 21, 22, 100, 75, 50, 28, 19, and 11 of the main control chip U77 are connected to a voltage of 3.3V, and pins 22, 100, 75, 50, 28, 19, and 11 of the main control chip U77 are also grounded to GND through capacitors C137, C134, C135, C136, C138, C139, and C140 respectively.

[0148] Pin 73 of the master control chip U77 is grounded to GND through capacitor C142, pin 49 of the master control chip U77 is grounded to GND through capacitor C141, pin 94 of the master control chip U77 is grounded to GND through resistor R209, pin 37 of the master control chip U77 is grounded to GND through resistor R210, pins 47 and 48 of the master control chip U77 are reserved pins, and pins 86 and 87 of the master control chip U77 are connected to the slave machine.

[0149] The main control module mainly uses the ADC function of the MCU. The ADC (Analog-to-Digital Converter) is usually based on the successive approximation register (SAR) architecture. Its working principle is as follows:

[0150] Sampling phase: During the sampling phase, the ADC holds the analog input signal on the sampling capacitor through the sampling switch to stabilize the input voltage. The sampling time determines the sampling duration of the input signal, affecting the accuracy and speed of the conversion. A longer sampling time helps improve accuracy but reduces the sampling rate.

[0151] Conversion phase: In the conversion phase, the ADC compares the analog voltage with the reference voltage through a successive approximation algorithm to generate a corresponding digital value. In this process, the ADC will gradually approach the voltage value of the analog input signal until it finds a digital code that is equal to the analog voltage. Figure 6, U76 is the LCD screen interface, and H13 is the programming interface.

[0152] This embodiment can conveniently collect the position or voltage difference of the target contact in each sub-monitoring module through the main control module and the voltage monitoring module.

[0153] In one embodiment, the monitoring system for an open zero-sequence voltage loop further includes a display module connected to the main control module;

[0154] The display module is used to display the options corresponding to different sub-monitoring modules to the user through the display screen, receive the user's selection operation on the options corresponding to the target sub-monitoring module, generate corresponding specified monitoring instructions in response to the selection operation, and output the specified monitoring instructions to the main control module.

[0155] Specifically, the display module includes a display screen and a display screen control unit. The display screen control unit is connected to the main control module. The display screen can display a human-computer interaction interface for the user to select the target sub-monitoring module to be started.

[0156] The display screen control unit can receive the user's selection operation through the display screen, generate a specified monitoring instruction according to the received selection operation, and send the specified monitoring instruction to the main control module.

[0157] The main control module generates a monitoring start instruction for the target sub-monitoring module according to the specified monitoring instruction, and each target sub-monitoring module corresponds to a monitoring start instruction.

[0158] Taking 12 sub-monitoring modules as an example, among which, 6 first sub-monitoring modules correspond to 6 groups of AC100V relay groups, each first sub-monitoring module corresponds to a group of AC100V relay groups, and each AC100V relay group includes a first voltage relay module (including a first voltage relay) and a second voltage relay module (including a second voltage relay).

[0159] Similarly, the 6 second sub-monitoring modules correspond to 6 groups of AC33.3V relay groups, each second sub-monitoring module corresponds to a group of AC33.3V relay groups, and each AC33.3V relay group includes a first voltage relay module (including a first voltage relay) and a second voltage relay module (including a second voltage relay).

[0160] The first voltage relay and the second voltage relay included in the AC100V relay group are different from the first voltage relay and the second voltage relay included in the AC33.3V relay group.

[0161] During use, it is necessary to select which relay groups to use on the display screen. Since the relay group corresponds to the sub-monitoring module, and the sub-monitoring module corresponds to the zero-sequence voltage circuit, selecting the relay group is equivalent to selecting the target sub-monitoring module and the zero-sequence voltage circuit to be controlled.

[0162] like Figure 7 As shown, Figure 7 The upper middle picture shows the default interface of the operating system installed in the monitoring system of the open zero-sequence voltage loop. "View voltage" and "Access group number" are clickable buttons. Click "View voltage" to enter the voltage viewing interface. Click "Access group number" to enter Figure 7 The relay group enable interface in the middle figure shows that there are 6 selectable relay groups for AC100V and 6 selectable relay groups for AC33.3V. In this relay enable interface, the user can click to confirm the target relay group. For example, the first and second relay groups in AC100V are selected, and the first and second relay groups in AC33.3V are selected.

[0163] The display control unit can receive the user's selection operation through the display screen, and generate a specified monitoring instruction according to the received selection operation, and send the specified monitoring instruction to the main control module. The specified monitoring instruction carries the unique identifiers of the first and second relay groups in AC100V and the first and second relay groups in AC33.3V. The main control module can generate a monitoring start instruction for the relay group in the target sub-monitoring module according to the unique identifier of the selected relay group.

[0164] In another specific embodiment, the monitoring system of the open zero-sequence voltage circuit also includes a key module connected to the main control module; the key module is used to receive and respond to the user's key operation, generate corresponding specified monitoring instructions, and output the specified monitoring instructions to the main control module.

[0165] This embodiment provides a display module in the monitoring system of the open zero-sequence voltage loop, and realizes friendly human-computer interaction through the display interface, so as to facilitate the user to specify the monitoring target zero-sequence voltage loop.

[0166] In one embodiment, the monitoring system for an open zero-sequence voltage loop further includes a display module connected to the main control module;

[0167] The display module is used to display the voltage between the first contact and the eighth contact of the first relay and / or the voltage between the first contact and the eighth contact of the second relay to the user through a display screen.

[0168] Specifically, Figure 7The following figure is the voltage viewing interface, which is used to display the voltage between the first contact and the eighth contact of the first relay in each relay group, and the voltage between the first contact and the eighth contact of the second relay. Figure 5 The voltage difference between the potential 110_N1 of the first contact of the first relay U1 and the potential 110_P1 of the eighth contact of the first relay U1, and the voltage difference between the potential 110_N2 of the first contact of the second relay U7 and the potential 110_P2 of the eighth contact of the first relay U1.

[0169] This embodiment provides a display module in the monitoring system of the open zero-sequence voltage loop, and realizes friendly human-computer interaction through the display interface, so that the user can check the monitored voltage conveniently.

[0170] In one embodiment, the monitoring system of the open zero-sequence voltage loop further includes an isolated step-down power supply module, which is used to convert the input voltage into at least one target voltage and use the target voltage to power other modules.

[0171] Specifically, Figure 8 is a circuit diagram of a power module in one embodiment; Figure 8 Pins 6 and 5 of U29 are connected to the first ends of capacitors C4, C5, C6 and C7 respectively, pins 3 and 4 of U29 are connected to the second ends of capacitors C5 and C4 respectively, the second end of capacitor C5 is connected to the second ends of capacitors C6 and C7 respectively through inductor L7, pins 6 and 5 of U29 are also connected to the first end of U31, the second ends of capacitors C6 and C7 are also connected to the second end of U31, the third end of U31 is grounded, the fourth end of U31 outputs a voltage of 24V, the fourth end of U31 is also grounded through capacitor C8, and the fourth end of U31 is also grounded to capacitor C9. Pin 2 of U29 is connected to the first end of U30, and pin 2 of U29 is also connected to the PE line (Protective Earth) through capacitor C2. Pin 1 of U29 is connected to the second end of U30, and pin 1 of U29 is also connected to the PE line through capacitor C3. The third end of U30 is connected to the L line (Live Line) through resistors R1 and F25. The third end of U30 is also connected to the first ends of capacitor C1, resistor R3, and resistor R2 respectively. The fourth end of U30 is also connected to the second ends of capacitor C1, resistor R3, and resistor R2 and N line (Neutral Line) respectively.

[0172] The L line (Live Line), N line (Neutral Line) and PE line (Protective Earth) are connected through the terminal U73.

[0173] U29 can convert AC power into 24V voltage.

[0174] Pin 1 of U32 is connected to the output end through capacitor C22 and inductor L2 in sequence, and the output end outputs voltage VCC. Pin 2 of U32 is connected to voltage 24V, and pin 2 of U32 is also connected to ground GND through parallel capacitors C26 and C27. Pin 3 of U32 is connected to voltage 24V through resistor R18, pin 4 of U32 is grounded through resistor R19, and pin 3 of U32 is also grounded through resistor R24. Pin 8 of U32 is connected to the output end through inductor L2, and pin 8 of U32 is also grounded through D1. Pins 7 and 9 of U32 are grounded, pin 6 of U32 is grounded through capacitor C28, and pin 5 of U32 is grounded through resistor R21. The two ends of capacitor C23 are connected to the output end and ground respectively, and the two ends of capacitor C24 are connected to the output end and ground respectively, and the output end is grounded through resistors R17 and R21.

[0175] U32 can convert 24V voltage into voltage VCC to power other modules.

[0176] U29 is an isolated step-down power supply module, the power input range is 85V~275VAC or 100V~370VDC, and the output is DC24V. F25 is a fuse, and the design refers to the EMC application circuit of the High Energy Cube HS-36W series data sheet. Figure 8 U32 is the LMR14050 device, a 40V, 5A step-down regulator with an integrated high-side MOSFET. The device has a wide input voltage range of 4V to 40V. The regulator has a wide adjustable switching frequency range and built-in protection features: cycle-by-cycle current limit protection, thermal sensing and thermal shutdown protection for excessive power dissipation, and output overvoltage protection.

[0177] It should be noted that the resistance, capacitance, inductance, voltage, model and other values ​​of the electronic components in the various circuit diagrams of this application are only exemplary. In actual applications, the resistance, capacitance, inductance, voltage, model and other properties of the electronic components are adjusted according to actual conditions, and this application does not impose any restrictions on this.

[0178] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0179] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0180] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A monitoring system for an open zero-sequence voltage loop, characterized in that: The monitoring system of the open zero-sequence voltage loop includes at least one sub-monitoring module, and different sub-monitoring modules are connected to and monitor a different zero-sequence voltage loop; each sub-monitoring module includes a first voltage relay module, a second voltage relay module, a first fuse module and a second fuse module; each zero-sequence voltage loop includes a secondary open delta winding of a bus voltage transformer; The first voltage relay module is connected in series with the first fuse module and then connected to the first end and the second end of the secondary open triangle winding of the bus voltage transformer; The second voltage relay module is connected in series with the second fuse module and then connected to the third end and the fourth end of the secondary open triangle winding of the bus voltage transformer; Wherein, the bus voltage transformer secondary open delta winding comprises voltage transformer secondary windings YHA, YHB and YHC connected in series, and the first end, the second end, the third end and the fourth end of the bus voltage transformer secondary open delta winding are different series connection points in the bus voltage transformer secondary open delta winding; The normally closed contacts of the first voltage relay module and the second voltage relay module are both connected to the measurement and control module; The first voltage relay module and the second voltage relay module are both used to monitor the wiring status of the corresponding zero-sequence voltage circuit, and output a feedback signal reflecting the actual wiring status of the zero-sequence voltage circuit to the measurement and control module, wherein the actual wiring status includes the presence of a broken wire and normal.

2. The monitoring system for an open zero-sequence voltage loop according to claim 1, characterized in that: Each sub-monitoring module also includes an alarm module connected to the first voltage relay module and the second voltage relay module; The first voltage relay module and the second voltage relay module are further used to control the corresponding alarm module to issue an alarm prompt when the actual wiring condition of the zero-sequence voltage circuit is a disconnection.

3. The monitoring system for an open zero-sequence voltage loop according to claim 1, characterized in that: The monitoring system for the open zero-sequence voltage loop also includes a main control module connected to each sub-monitoring module; The main control module is used to receive and respond to the user's specified monitoring instructions and generate a monitoring start instruction for the target sub-monitoring module; The target sub-monitoring module is used to start and monitor the connection status of the corresponding zero-sequence voltage circuit after receiving the monitoring start instruction.

4. The monitoring system for an open zero-sequence voltage loop according to claim 1, characterized in that: The first voltage relay module includes a first relay; the second voltage relay module includes a second relay; The first contact of the first relay is connected to the second end of the secondary open delta winding of the bus voltage transformer through a pin of the first wiring terminal, and the eighth contact of the first relay is connected to the first end of the secondary open delta winding of the bus voltage transformer through the first fuse, the first protection resistor, and the other pin of the first wiring terminal in sequence; the sixth contact of the first relay is connected to the first voltage, and the seventh contact of the first relay is connected to the measurement and control module; The first relay is specifically used to connect the sixth contact and the seventh contact of the first relay if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop, and output the first voltage to the measurement and control module; The first relay is specifically used to connect the sixth contact and the fifth contact of the first relay if there is no disconnection in the first associated line in the monitored zero-sequence voltage loop, so that the seventh contact of the first relay has no output; The first contact of the second relay is connected to the fourth end of the secondary open delta winding of the bus voltage transformer through a pin of the second wiring terminal, and the eighth contact of the second relay is connected to the third end of the secondary open delta winding of the bus voltage transformer through the second fuse, the second protection resistor, and the other pin of the second wiring terminal in sequence; the sixth contact of the second relay is connected to the first voltage, and the seventh contact of the second relay is connected to the measurement and control module; The second relay is specifically used to connect the sixth contact and the seventh contact of the second relay if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop, and output the first voltage to the measurement and control module; The second relay is specifically used to connect the sixth contact and the fifth contact of the second relay if there is no disconnection in the second associated line in the monitored zero-sequence voltage loop, so that the seventh contact of the second relay has no output.

5. The monitoring system for an open zero-sequence voltage loop according to claim 4, characterized in that: The third contact of the first relay is connected to the second voltage; the second contact of the first relay is connected to the first alarm module through the first alarm resistor and the third wiring terminal; The first relay is further used for connecting the third contact of the first relay with the second contact to trigger the first alarm module to alarm if there is a disconnection in the first associated line in the monitored zero-sequence voltage loop; The third contact of the second relay is connected to the second voltage; the second contact of the second relay is connected to the second alarm module through the second alarm resistor and the fourth terminal; The second relay is further used to connect the third contact of the second relay with the second contact if a second associated line in the monitored zero-sequence voltage loop is broken, so as to trigger the second alarm module to alarm.

6. The monitoring system for an open zero-sequence voltage loop according to claim 4 or 5, characterized in that: Each sub-monitoring module also includes a first monitoring startup module; The first monitoring start module is used to connect the first voltage to the sixth contact of the first relay and the sixth contact of the second relay if a first monitoring start instruction is received.

7. The monitoring system for an open zero-sequence voltage loop according to claim 5, characterized in that: Each sub-monitoring module also includes a second monitoring startup module; The second monitoring start module is used to connect the second voltage to the third contact of the first relay and the third contact of the second relay if a second monitoring start instruction is received.

8. The monitoring system for an open zero-sequence voltage loop according to claim 6, characterized in that: The first monitoring start module includes a switch control unit, a switch tube, a first resistor, a second resistor and a first diode; the first end of the switch tube can obtain the first monitoring start instruction through the first resistor, the second end of the switch tube is grounded, the third end of the switch tube is connected to the third voltage through the second resistor and the first diode, the third end of the switch tube is also connected to the third voltage through the second resistor, the sixth pin and the first pin of the switch control unit in sequence, the second pin of the switch control unit is connected to the first voltage, and the third pin of the switch control unit is respectively connected to the sixth contact of the first relay and the sixth contact of the second relay U7.

9. The monitoring system for an open zero-sequence voltage loop according to claim 4, characterized in that: The monitoring system for the open zero-sequence voltage loop also includes a main control module and a voltage monitoring module that are electrically connected, wherein different sub-monitoring modules are correspondingly connected to a different voltage monitoring module; The main control module is used to monitor the voltage between the first contact and the eighth contact of the first relay through the voltage monitoring module, and / or monitor the voltage between the first contact and the eighth contact of the second relay.

10. The monitoring system for an open zero-sequence voltage loop according to claim 3, characterized in that: The monitoring system for the open zero-sequence voltage loop also includes a display module connected to the main control module; The display module is used to display the optional items corresponding to different sub-monitoring modules to the user through a display screen, receive the user's selection operation on the optional items corresponding to the target sub-monitoring module, generate corresponding designated monitoring instructions in response to the selection operation, and output the designated monitoring instructions to the main control module.

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