Monitoring system for open zero sequence voltage loop

Abstract

The application discloses a monitoring system of an open zero sequence voltage loop, and 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 connected to a first end and a second end of a secondary open delta winding of a bus voltage transformer; the second voltage relay module is connected in series with the second fuse module and then connected to a third end and a fourth end of the secondary open delta winding of the bus voltage transformer; the first voltage relay module and the second voltage relay module are connected with a monitoring 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 monitoring and control module. In the case that the zero sequence voltage loop is disconnected, the disconnection condition of the zero sequence voltage loop can be accurately and timely monitored and reflected by changing the state of relay contacts.

Description

Technical Field

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

[0002] Within power systems, the opening of the secondary open delta winding of the bus voltage transformer, which is included in the zero-sequence voltage circuit, frequently occurs due to reasons such as poor contact of the auxiliary contacts of the bus voltage transformer disconnector and burnt-out contacts of the zero-sequence voltage circuit switching relay of the voltage transformer parallel device. During normal system operation, there is no zero-sequence voltage in the zero-sequence voltage circuit, and its unbalanced voltage is very small, generally about 3-5V, varying with the load. When the zero-sequence voltage circuit is disconnected, due to the influence of induced voltage, the induced voltage value of the open delta winding at the time of disconnection is close to the voltage value on the secondary open delta winding of the bus voltage transformer during normal operation. Therefore, it is difficult to detect the disconnection of the zero-sequence voltage circuit when induced voltage is present. Summary of the Invention

[0003] Based on this, it is necessary to address the technical problem that it is difficult to monitor the open circuit of the zero-sequence voltage loop in the existing technology, and propose a monitoring system for the open zero-sequence voltage loop.

[0004] A monitoring system for an open zero-sequence voltage loop is provided. The monitoring system for an open zero-sequence voltage loop includes a measurement and control module and at least one sub-monitoring module. Different sub-monitoring modules are connected to and monitor different zero-sequence voltage loops. 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.

[0005] The first voltage relay module is connected in series with the first fuse module and then connected to the first and second ends of the secondary open delta 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 and fourth terminals of the secondary open delta winding of the bus voltage transformer.

[0007] Among them, the secondary open delta winding of the bus voltage transformer includes the secondary windings YHA, YHB and YHC of the voltage transformer connected in series. The first end, the second end, the third end and the fourth end of the secondary open delta winding of the bus voltage transformer are different series connection points in the secondary open delta winding of the bus voltage transformer.

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

[0009] 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 reflecting actual wiring conditions of the zero sequence voltage loops to the measurement and control module, wherein the actual wiring conditions include existence of disconnection and normality.

[0010] The monitoring system of the open zero sequence voltage loop provided in the application utilizes the voltage relay module in the sub-monitoring module to be connected with the zero sequence voltage loop, and the integrity of the connection of the zero sequence voltage loop determines the voltage borne by the voltage relay, which further affects the closing or opening of the contact in the voltage relay. Based on this, the disconnection condition of the zero sequence voltage loop can be accurately and timely reflected by changing the state of the relay contact in the case of disconnection of the zero sequence voltage loop, and the technical problem that the disconnection of the zero sequence voltage loop is difficult to monitor due to the interference of induced current in the prior art is solved. The disconnection problem of the zero sequence voltage loop can be monitored in real time by the application, so that faults can be found and solved in time, and the harm of the disconnection of the zero sequence voltage loop to the power grid can be prevented in time, thereby effectively ensuring the safe operation of other equipment of the power grid. In addition, the application can monitor the disconnection of different zero sequence voltage loops through different sub-monitoring modules, and has high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0012] Among them:

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

[0014] Figure 2 It is a wiring schematic diagram of the sub-monitoring module and the corresponding zero sequence voltage loop in an embodiment;

[0015] Figure 3 It is a wiring schematic diagram of a sub-monitoring module, a zero sequence voltage loop and a measurement and control module in an embodiment;

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

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

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

[0019] Figure 7 Fig. 1 is a schematic diagram of a zero sequence voltage monitoring interface in one embodiment;

[0020] Figure 8 Fig. 2 is a circuit diagram of a power module in one embodiment. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

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

[0023] Due to poor contact of PT (Potential Transformer, referred to as PT) disconnector contacts, burning of PT parallel device zero sequence voltage loop switching relay contacts, loosening of wiring terminals, etc., the zero sequence voltage loop may be disconnected, and the related protection device cannot collect the zero sequence voltage, which affects the action logic of the protection device and endangers the reliable operation of the power grid.

[0024] According to the enterprise countermeasures, the zero sequence voltage loop cannot be controlled by the air switch protection, to prevent the air switch from being in the open position during normal operation and the device from having any reaction, and to prevent the related protection device from being unable to collect the zero sequence voltage when a fault occurs, which affects the action logic of the protection device. Without the protection of the air switch, the zero sequence voltage loop is prone to be burned out due to the short circuit of the zero sequence voltage loop and the burning of the potential transformer PT parallel device and the voltage switching device.

[0025] Therefore, it is necessary to monitor the disconnection of the zero sequence voltage loop.

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

[0027] As Figure 1As shown, in one embodiment, a monitoring system of open zero sequence voltage loop is provided. The monitoring system of open zero sequence voltage loop comprises at least one sub-monitoring module, different sub-monitoring modules are connected and monitor one 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 bus voltage transformer secondary open delta winding;

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

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

[0030] 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 connection points in the bus voltage transformer secondary open delta winding;

[0031] The normally closed contact of the first voltage relay module and the normally closed contact of the second voltage relay module are connected with the monitoring and control module;

[0032] The first voltage relay module and the second voltage relay module are used for monitoring the wiring condition of the corresponding zero sequence voltage loop, and output feedback signals reflecting the actual wiring condition of the zero sequence voltage loop to the monitoring and control module, wherein the actual wiring condition includes a broken line and normal.

[0033] Specifically, the monitoring system of open zero sequence voltage loop comprises at least one sub-monitoring module (for example, sub-monitoring modules 1-n), as shown in Figure 1 Each sub-monitoring module is connected with one zero sequence voltage loop, and different sub-monitoring modules (sub-monitoring modules 1-n) are connected with different zero sequence voltage loops (zero sequence voltage loops 1-n), which means that each sub-monitoring module monitors one zero sequence voltage loop. The sub-monitoring module is also connected with the monitoring and control module.

[0034] Each zero sequence voltage loop comprises a bus voltage transformer secondary open delta winding, each bus voltage transformer secondary open delta winding comprises 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 connection points in the bus voltage transformer secondary open delta winding.

[0035] Each sub-monitoring module of the embodiment accesses the bus voltage transformer secondary open delta winding of the zero sequence voltage circuit under its jurisdiction to monitor whether the series connection point between the secondary windings of the voltage transformer is in poor contact and causes disconnection.

[0036] Figure 2 The figure shows the connection of a sub-monitoring module and the corresponding zero sequence voltage circuit in an embodiment. The connection of each sub-monitoring module and the bus voltage transformer secondary open delta winding of the zero sequence voltage circuit under its jurisdiction is specifically as shown in the figure. Figure 2

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

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

[0039] That is, Figure 2 The YJa coil of the first voltage relay module is connected in parallel into the circuit of the bus voltage transformer secondary open delta winding connection head end L630 and YHA head end da after the first fuse module RD1 is connected in series, the YJb coil of the second voltage relay module is connected in parallel into the circuit of the bus voltage transformer secondary open delta winding connection tail end N600 and YHC tail end dn after the second fuse module RD2 is connected in series, and the normally closed contact (normally closed auxiliary contact) of the YJa and YJb voltage relays is connected in parallel into the incoming signal circuit of the monitoring module.

[0040] Or,

[0041] The connection of each sub-monitoring module and the bus voltage transformer secondary open delta winding of the zero sequence voltage circuit under its jurisdiction is specifically as shown in the figure.

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

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

[0044] Or,

[0045] The connection of each sub-monitoring module and the bus voltage transformer secondary open delta winding of the zero sequence voltage circuit under its jurisdiction is specifically as shown in the figure. ​

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

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

[0048] Of course, the above-mentioned access method is only illustrative, and the present application does not limit the access method.

[0049] In a specific embodiment, when the system is normally running, at this time, if the zero sequence voltage loop is intact, the voltage borne by the voltage relay in the voltage relay module YJa and YJb is about 100V, and the voltage relay is started. If the loop ab is disconnected, 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 loop cd is disconnected, 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 loop bc is disconnected, the voltage borne by the voltage relay YJa and YJb will be less than the starting value; if the auxiliary contact of the bus voltage transformer disconnector is not in good contact, the voltage switching relay contact of the PT parallel device is disconnected, the series joint contact of the secondary winding YHA, YHB and YHC of the voltage transformer is disconnected, at least one voltage relay YJa or YJb will bear a voltage less than the starting value, and the voltage relay will not start. The specific situation is shown in Table 1:

[0050] Table 1

[0051]

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

[0053] According to the wiring mode of 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 govern and monitor different associated lines in the same zero sequence voltage loop.

[0054] When the system is normal, i.e. the zero sequence voltage circuit is not broken, the first voltage relay module YJa has voltage, i.e. is greater than the starting voltage, the normally closed contact 2 (YJa1) is opened (disconnected), and XD_OUT = 0. When the system is abnormal, i.e. the first associated line of the zero sequence voltage circuit is broken, the first voltage relay module YJa has no voltage, i.e. is less than the starting voltage, the normally closed contact 2 (YJa1) is closed, and XD_OUT = XD_IN.

[0055] Similarly, when the system is normal, i.e. the zero sequence voltage circuit is not broken, the second voltage relay module YJb has voltage, i.e. is greater than the starting voltage, the normally closed contact 2 (YJb1) is opened (disconnected), and XD_OUT = 0. When the system is abnormal, i.e. the second associated line of the zero sequence voltage circuit is broken, the second voltage relay module YJb has no voltage, i.e. is less than the starting voltage, the normally closed contact 2 (YJb1) is closed, and XD_OUT = XD_IN.

[0056] Since XD_IN is connected to the first voltage +XD, when the line is broken, the monitoring module can obtain the feedback signal indicating that the zero sequence voltage circuit is broken.

[0057] If the zero sequence voltage circuit is normal and has no broken line, XD_OUT = 0, and the monitoring module can obtain the feedback signal indicating that the zero sequence voltage circuit is normal.

[0058] Alternatively, the monitoring module only obtains the feedback signal indicating that the zero sequence voltage circuit is broken when the line is broken, and the monitoring module does not receive the feedback signal when there is no broken line.

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

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

[0061] The monitoring system of the open zero sequence voltage loop provided by the embodiment utilizes the voltage relay module in the sub-monitoring module to be connected with the zero sequence voltage loop, and the integrity of the connection of the zero sequence voltage loop determines the bearing voltage of the voltage relay, and further affects the closing or opening of the contact in the voltage relay. Based on this, in the case of disconnection of the zero sequence voltage loop, the disconnection condition of the zero sequence voltage loop can be accurately and timely reflected by changing the state of the relay contact, and the technical problem that the disconnection of the zero sequence voltage loop is difficult to monitor due to the interference of induced current in the prior art is solved. The disconnection problem of the zero sequence voltage loop can be monitored in real time by the embodiment, so that the fault can be found and solved in time, the harm of the disconnection of the zero sequence voltage loop to the power grid is prevented in time, the operation safety of other equipment of the power grid is effectively ensured, and the embodiment can monitor the disconnection of different zero sequence voltage loops through different sub-monitoring modules, and has high practicability.

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

[0063] The first voltage relay module and the second voltage relay module are further configured to control the corresponding alarm module to alarm when the actual wiring condition of the zero sequence voltage loop is disconnection.

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

[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 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 alarm.

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

[0068] Figure 3 The alarm module is the alarm lamp 1 and the alarm lamp 2, and in other embodiments, the alarm module can also be a buzzer, a sound emitting device, a display screen, etc., and the application does not limit the alarm module.

[0069] When the system is normal, i.e., the zero sequence voltage circuit does not have a broken line, the first voltage relay module YJa has a voltage, i.e., greater than the starting voltage, and the normally closed contact 1 is opened (disconnected); when the system is faulty, a broken line occurs in the first associated line of the zero sequence voltage circuit, and the first voltage relay module YJa has no voltage, i.e., less than the starting voltage, and the normally closed contact 1 is closed, so that the POWERLED_IN is connected to the second voltage POWER_LED+, and because the other end of the alarm lamp 1 is connected to the negative voltage POWER_LED-, the alarm lamp 1 can alarm.

[0070] Similarly, when the system is normal, i.e., the zero sequence voltage circuit does not have a broken line, the second voltage relay module YJb has a voltage, i.e., greater than the starting voltage, and the normally closed contact 1 is opened (disconnected); when the system is faulty, a broken line occurs in the second associated line of the zero sequence voltage circuit, and the second voltage relay module YJb has no voltage, i.e., less than the starting voltage, and the normally closed contact 1 is closed, so that the POWERLED_IN is connected to the second voltage POWER_LED+, and because the other end of the alarm lamp 2 is connected to the negative voltage POWER_LED-, the alarm lamp 2 can alarm.

[0071] Reference Figure 2 and Figure 3 A sub-monitoring module is the smallest monitoring unit, and has four wiring ports a, b, c, and d corresponding to the four wiring points in Figure 2 , +XD and -XD are the remote signaling power inputs. For a sub-monitoring module, there are 6 connection lines a, b, c, d corresponding to the four wiring points of the delta winding in Figure 2 . +XD and -XD are connected to the remote signaling power. The normally closed contact 2 of the two relays is connected in parallel, and then connected to the measurement and control module. At this time, if ac is faulty, the alarm lamp 1 emits light, and the measurement and control module sends a fault signal to the master station.

[0072] If db is faulty, the alarm lamp 2 emits light, and the measurement and control module sends a fault signal to the master station.

[0073] If bc is faulty, the alarm lamps 1 and 2 both emit light, and the measurement and control module sends a fault signal to the master station.

[0074] The embodiment can alarm when there is a broken line in the zero sequence voltage circuit by setting the alarm module, which plays an effective and timely prompting role.

[0075] In an embodiment, the monitoring system of the open zero sequence voltage circuit further comprises a master control module connected to each sub-monitoring module;

[0076] The master control module is configured to receive and respond to a specified monitoring instruction of a user, and generate a monitoring start instruction for a target sub-monitoring module;

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

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

[0079] In order to realize the selectivity and targeted monitoring of some zero sequence voltage loops, the open zero sequence voltage loop monitoring system of the embodiment is provided with a master control module. The master control module can receive the specified monitoring instruction of the user, and generate a monitoring start instruction according to the specified monitoring instruction, and use the monitoring start instruction to control the target sub-monitoring module to start the monitoring function. The other sub-monitoring modules that do not receive the monitoring start instruction do not start the monitoring function temporarily.

[0080] The master control module can obtain the specified monitoring instruction of the user through a wireless communication mode, or receive the specified monitoring instruction of the user through an instruction receiving module. The instruction receiving module is connected with the master control module. The instruction receiving module can be part of the open zero sequence voltage loop monitoring system, or can be an external device, such as a button, a key, a touchable display screen, etc. The present application does not limit this.

[0081] The master control module can control any sub-monitoring module to start the monitoring function, and realize personalized and targeted monitoring.

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

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

[0084] The first relay is specifically configured to, if the first associated line in the monitored zero sequence voltage loop exists a disconnection, connect the sixth contact and the seventh contact of the first relay, and output the first voltage to the monitoring and control module.

[0085] The sixth contact and the fifth contact of the first relay are communicated if there is no disconnection in the first associated line in the monitored zero sequence voltage loop, and the seventh contact of the first relay is not outputted.

[0086] The first contact of the second relay is connected with the fourth end in the secondary open triangular winding of the bus voltage transformer through a pin of the second terminal, and the eighth contact of the second relay is connected with the third end in the secondary open triangular winding of the bus voltage transformer through the second fuse, the second protection resistor and another pin of the second terminal in turn; the sixth contact of the second relay is connected with the first voltage, and the seventh contact of the second relay is connected with the monitoring and control module.

[0087] The sixth contact and the seventh contact of the second relay are communicated if there is a disconnection in the first associated line in the monitored zero sequence voltage loop, and the first voltage is outputted to the monitoring and control module.

[0088] The sixth contact and the fifth contact of the second relay are communicated if there is no disconnection in the second associated line in the monitored zero sequence voltage loop, and the seventh contact of the second relay is not outputted.

[0089] Specifically, Figure 4 The circuit diagram of the sub-monitoring module in one embodiment is shown in FIG. 1. Figure 4 Each sub-monitoring module includes two relays (two relays form a relay group).

[0090] The first voltage relay module includes the first relay U1, and the second voltage relay module includes the second relay U7.

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

[0092] The sixth contact (contact 6) and the seventh contact (contact 7) of the first relay U1 are communicated if there is a disconnection in the first associated line in the monitored zero sequence voltage loop, and the first voltage XD_IN (i.e., +XD) is outputted to the monitoring and control module.

[0093] The first relay U1 is specifically configured to, if there is no disconnection in the first associated line in the monitored zero sequence voltage loop, connect the sixth contact (contact 6) and the fifth contact (contact 5) of the first relay U1, and make the seventh contact (contact 7) of the first relay U1 have no output, that is, XD_OUT is an empty signal.

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

[0095] The first contact (contact 1) of the second relay U7 is connected with the fourth end in the secondary opening triangular winding of the bus voltage transformer through the pin 1 of the second terminal U60, the eighth contact (contact 8) of the second relay U7 is connected with the third end in the secondary opening triangular winding of the bus voltage transformer through the second fuse F7, the second protection resistor R228 and the pin 2 of the second terminal U60 in turn; the sixth contact (contact 6) of the second relay U7 is connected with the first voltage XD_IN (that is, +XD), and the seventh contact (contact 7) of the second relay U7 is connected with the monitoring and control module to output the signal XD_OUT to the monitoring and control module.

[0096] The second relay U7 is specifically configured to, if there is a disconnection in the first associated line in the monitored zero sequence voltage loop, connect the sixth contact and the seventh contact of the second relay U7, and output the first voltage XD_IN (that is, +XD) to the monitoring and control module.

[0097] The second relay U7 is specifically configured to, if there is no disconnection in the second associated line in the monitored zero sequence voltage loop, connect the sixth contact and the fifth contact of the second relay U7, and make the seventh contact of the second relay U7 have no output, that is, XD_OUT is an empty signal.

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

[0099] The embodiment can conveniently monitor whether the zero sequence voltage loop is disconnected through the two relays, and give feedback signals in time.

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

[0101] The first relay is further configured to, if there is a disconnection in the first associated line in the monitored zero sequence voltage loop, connect the third contact and the second contact of the first relay 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 a second alarm resistor and a fourth terminal;

[0103] The second relay is further configured to, if a second associated line in the monitored zero sequence voltage loop has a disconnection, connect the third contact and the second contact of the second relay to trigger the second alarm module to alarm.

[0104] Specifically, Figure 4 The circuit diagram of the sub-monitoring module in one embodiment is shown in FIG. 1; Figure 4 The third contact (contact 3) of the first relay U1 is connected to the second voltage LED 3.3V; the second contact (contact 2) of the first relay U1 is connected to the first alarm module through a first alarm resistor R161 and a pin 1 of a third terminal H1; a pin 2 of the third terminal H1 is connected to the ground. The third terminal H1 is connected to the first alarm module.

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

[0106] The first relay U1 is further configured to, if a first associated line in the monitored zero sequence voltage loop has a disconnection, connect the third contact (contact 3) and the second contact (contact 2) of the first relay U1 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 LED 3.3V; the second contact (contact 2) of the second relay U7 is connected to the second alarm module through a second alarm resistor R166 and a pin 1 of a fourth terminal H19; a pin 2 of the fourth terminal H19 is connected to the ground. The fourth terminal H19 is connected to the second alarm module.

[0108] The second relay U7 is further configured to, if a second associated line in the monitored zero sequence voltage loop has a disconnection, connect the third contact (contact 3) and the second contact (contact 2) of the second relay U7 to trigger the second alarm module to alarm.

[0109] The first relay U1 is further configured to, if a first associated line in the monitored zero sequence voltage loop has no disconnection, connect the third contact and the fourth contact of the first relay U1 to prevent the first alarm module from alarming.

[0110] The second relay U7 is further configured to, if a second associated line in the monitored zero sequence voltage loop has no disconnection, connect the third contact and the fourth contact of the second relay U7 to prevent the second alarm module from alarming.

[0111] The embodiment increases the alarm module, and utilizes the relay to control the alarm module to alarm when the line is disconnected, so that effective alarm prompting is achieved.

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

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

[0114] Specifically, Figure 4 For a circuit diagram of the sub-monitoring module in one embodiment; refer to Figure 4 The first monitoring starting module comprises 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 starting instruction RELAY_EN1 through the resistor R186, for example, the first end of the switch tube Q1 is connected to the master control module through the resistor R186, and the first monitoring starting instruction RELAY_EN1 is sent by the master control module. 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 in sequence, 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 connected to the contact 6 of the first relay U1 and the contact 6 of the second relay U7 respectively.

[0115] The switch tube Q1 can 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 starting instruction RELAY_EN1, the switch tube Q1 is turned on, the pin 2 of the switch control unit K1 is connected to the pin 3, and then the first voltage XD_IN is connected to the sixth contact of the first relay U1 and the sixth contact of the second relay U2. Thus, the sub-monitoring module in which the first relay U1 and the second relay U2 are located starts to work, and monitors whether the corresponding zero sequence voltage loop is disconnected, that is, has the function of outputting XD_OUT.

[0117] If the first monitoring starting instruction RELAY_EN1 is not received or the first monitoring starting instruction RELAY_EN1 is a low voltage and cannot make Q1 conduct, the first voltage XD_IN is disconnected from the sixth contact of the first relay and the sixth contact of the second relay. Thus, 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, the terminal U58 can be provided, a pin 1 of the terminal U58 is connected with the first voltage XD IN and a pin 2 of the switch control unit K1, so as to connect the first voltage XD IN to the pin 2 of the switch control unit K1, and a pin 2 of the terminal U58 is connected with a pin 7 of the relay and the monitoring module, so as to output the output XD OUT of the pin 7 of the relay to the monitoring module.

[0119] The first monitoring starting module can be used to control whether the one or more sub-monitoring modules start the monitoring function.

[0120] In one embodiment, each sub-monitoring module further comprises a second monitoring starting module.

[0121] The second monitoring starting 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 the second monitoring starting instruction is received.

[0122] Specifically, Figure 4 The circuit diagram of the sub-monitoring module in one embodiment is shown in FIG. 4. Figure 4 The second monitoring starting module comprises a switch control unit K1, a switch Q1, a resistor R185, a resistor R186 and a diode D2. The first end of the switch Q1 can obtain the second monitoring starting instruction RELAY_EN1 through the resistor R186, for example, the first end of the switch Q1 is connected with the master control module through the resistor R186, and the second monitoring starting instruction RELAY_EN1 is sent by the master control module. The second end of the switch Q1 is grounded, the third end of the switch Q1 is connected with the voltage 24V through the resistor R185 and the diode D2, and the third end of the switch Q1 is also connected with the voltage 24V through the resistor R185, the pin 6 of the switch control unit K1 and the pin 1 in sequence, the pin 5 of the switch control unit K1 is connected with the second voltage LED3.3V, and the pin 4 of the switch control unit K1 is connected with the contact 3 of the first relay U1 and the contact 3 of the second relay U7 respectively.

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

[0124] If the switch Q1 receives the second monitoring starting instruction RELAY_EN1, the switch Q1 is turned on, the pin 5 of the switch control unit K1 is connected with the pin 4, and then the second voltage LED3.3V is connected to the third contact of the first relay U1 and the third contact of the second relay U2. Thus, the sub-monitoring module in which the first relay U1 and the second relay U2 are located can control whether the alarm module alarms, that is, has the alarm function.

[0125] If the second monitoring start command RELAY_EN1 is not received, or if the second monitoring start command RELAY_EN1 is a low voltage and cannot turn on Q1, then the second voltage LED3.3V will be disconnected from the third contact of the first relay and the third contact of the second relay. This prevents the first relay U1 and the second relay U2 from controlling the alarm module to sound an alarm, thus causing the corresponding sub-monitoring module to stop its 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, that is... 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 +XD in the equation means that after the switch is closed, XD_IN is the voltage +XD.

[0128] Figure 4 The second voltage in the LED is 3.3V. Figure 3 The voltage POWER_LED+ is the same as the voltage POWER_LED+ when the switch is closed.

[0129] This embodiment can control whether any one or more sub-monitoring modules activate the alarm function by setting a second monitoring startup module.

[0130] In conclusion, Figure 4 U60 is the secondary open delta winding terminal of the 110kV bus voltage transformer. U1 and U7 are voltage relays. During normal system operation, the relay coil is energized, the normally open contact closes, and the normally closed contact opens. In the event of a circuit break in any section, the relay coil is de-energized, the normally open contact opens, and the normally closed contact closes. The remote signaling 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 main station. The switch control unit K1 is a signal relay, which controls whether relays U1 and U7 have alarm functions by controlling the conduction and cutoff of transistor Q1. In this device, there are 6 AC100V relay groups and 6 AC33.3V relay groups. Relay K1 prevents unused relays from issuing alarms. H1 and H19 are connected to alarm lights, which illuminate when the corresponding line is short-circuited. 110_N1, 110_N2, 110_P1, and 110_P2 are voltage monitoring points that monitor the voltage received by 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 comprises a master control module and voltage monitoring modules connected electrically, wherein different sub-monitoring modules correspond to different voltage monitoring modules;

[0132] The master control module is configured to monitor the voltage between the first contact and the eighth contact of the first relay U1 and / or monitor the voltage between the first contact and the eighth contact of the second relay U7.

[0133] Specifically, Figure 4 The circuit diagram of the sub-monitoring module in one embodiment is shown in FIG. 4; Figure 4 The master control module is configured to monitor the voltage between the first contact and the eighth contact of the first relay U1, i.e. 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.

[0134] and / or

[0135] The master control module is further configured to monitor the voltage between the first contact and the eighth contact of the second relay U7, i.e. 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 The circuit diagram of the voltage monitoring module in one embodiment is shown in FIG. 5; Figure 5 The voltage monitoring module comprises two sub-voltage monitoring modules; the first sub-voltage monitoring module is configured 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 configured 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 the chip U28 is connected to the voltage 110_3.3V, pin 1 of the chip U28 is further connected to the ground through the capacitor C42, pins 2 and 3 are connected to both ends of the resistor R31, pin 2 is further connected to the eighth contact of the first relay U1 through the resistor R78 to obtain the potential 110_P1, and pin 3 is further connected to the first contact of the first relay U1 through the resistor R79 to obtain the potential 110_N1. Pin 4 of the chip U28 is connected to the ground. Pin 8 of the chip U28 is connected to the voltage GL13.3V, pin 8 of the chip U28 is further connected to the ground GND through the capacitor C43, pin 7 of the chip U28 is connected to the master control module through the resistor R32 to output a signal AD110_1 to the master control module, pin 7 of the chip U28 is further connected to the ground through the resistor R32 and the capacitor C44, and pins 6 and 5 of the chip U28 are connected to the ground.

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

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

[0140] Figure 6 The circuit diagram of the main control module in one embodiment; refer to Figure 6 The 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 switching tubes Q1 of 12 different sub-monitoring modules to respectively provide monitoring start instructions RELAY_EN1-RELAY_EN12.

[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 respectively receive the signals AD110_1-AD110_12. Each sub-monitoring module corresponds to a voltage monitoring module.

[0142] The pins 68 and 69 of the main control chip U77 are connected to the serial port screen through the terminal U76, the pin 4 of the terminal U76 is connected to the ground, and the pin 3 of the terminal U76 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 terminal H13. The pin 14 of the main control chip U77 is connected to the reset signal RST through the terminal H13.

[0144] One end of the resistor R15 is connected to the voltage 3.3V, the other end of the resistor R15 is connected to the ground through the capacitor C18, and the capacitor C18 is connected to the switch SW1, and the switch SW1 can generate the reset signal RST.

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

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

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

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

[0149] The master module mainly uses the ADC function of the MCU. ADC (Analog-to-Digital Converter) is usually based on the SAR (Successive Approximation Register) architecture, and its working principle is as follows:

[0150] Sampling phase: In 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 conversion accuracy and speed. Longer sampling time helps improve accuracy but reduces sampling rate.

[0151] Conversion phase: In the conversion phase, the ADC compares the analog voltage with the reference voltage through the successive approximation algorithm to generate the corresponding digital value. In this process, the ADC gradually approximates the voltage value of the analog input signal until it finds a digital code equal to the analog voltage. The partial circuit diagram of the MCU is shown in Figure 6U76 is a liquid crystal screen interface, and H13 is a programming interface.

[0152] The target contact point or the voltage difference in each sub-monitoring module can be conveniently collected by the master control module and the voltage monitoring module.

[0153] In one embodiment, the monitoring system of the open zero sequence voltage loop further comprises a display module connected with the master control module.

[0154] The display module is configured to display selectable items corresponding to different sub-monitoring modules on a display screen, receive a selection operation of a user on a selectable item corresponding to a target sub-monitoring module, generate a specified monitoring instruction in response to the selection operation, and output the specified monitoring instruction to the master control module.

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

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

[0157] The master 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 one monitoring start instruction.

[0158] For example, 12 sub-monitoring modules are included, 6 first sub-monitoring modules correspond to 6 groups of AC100V relay groups, each first sub-monitoring module corresponds to an AC100V relay group, 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, 6 second sub-monitoring modules correspond to 6 groups of AC33.3V relay groups, each second sub-monitoring module corresponds to an AC33.3V relay group, 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] In use, the user needs to select which groups of relay groups to use on the display screen. Since the relay groups correspond to the sub-monitoring modules, and the sub-monitoring modules correspond to the zero-sequence voltage loops, selecting the relay groups is equivalent to selecting the target sub-monitoring modules and the zero-sequence voltage loops to be controlled.

[0162] As shown in Figure 7 , Figure 7 The upper left figure is 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. Clicking "view voltage" can enter the voltage viewing interface. Clicking "access group number" can enter Figure 7 The relay group enable interface in the middle figure corresponds to 6 selectable relay groups for AC 100V, and also corresponds to 6 selectable relay groups for AC 33.3V. In the relay group enable interface, the user can select the target relay groups. For example, the first group of relay groups and the second group of relay groups in AC 100V are selected, and the first group of relay groups and the second group of relay groups in AC 33.3V are selected.

[0163] The display screen 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 group of relay groups and the second group of relay groups in AC 100V, and the unique identifiers of the first group of relay groups and the second group of relay groups in AC 33.3V. The main control module can generate a monitoring start instruction for the relay groups in the target sub-monitoring module according to the unique identifiers of the selected relay groups.

[0164] In another specific embodiment, the monitoring system of the open zero-sequence voltage loop further 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, and generate a corresponding specified monitoring instruction, and output the specified monitoring instruction to the main control module.

[0165] This embodiment realizes friendly human-computer interaction through the display interface by setting a display module in the monitoring system of the open zero-sequence voltage loop. It is convenient for the user to specify the monitoring target zero-sequence voltage loop.

[0166] In one embodiment, the monitoring system of the 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 the display screen.

[0168] Specifically, Figure 7The following figure in the voltage view interface is used to show 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] The embodiment realizes friendly human-computer interaction through the display module in the monitoring system of the open zero sequence voltage loop, and facilitates the user to view the monitored voltage through the display interface.

[0170] In one embodiment, the monitoring system of the open zero sequence voltage loop further comprises an isolation voltage reduction 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 The circuit diagram of the power supply module in one embodiment; refer to Figure 8 The first ends of capacitors C4, C5, C6 and C7 are connected to pins 6 and 5 of U29 respectively, the second ends of capacitors C5 and C4 are connected to pins 3 and 5 of U29 respectively, the second end of capacitor C5 is connected to the second ends of capacitors C6 and C7 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 through capacitor C9. Pin 2 of U29 is connected to the first end of U30, pin 2 of U29 is also connected to the PE line (Protective Earth, ground line) through capacitor C2, pin 1 of U29 is connected to the second end of U30, 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, live line) through resistor R1 and F25, the third end of U30 is also connected to the first ends of capacitor C1, resistor R3 and resistor R2 respectively, and the fourth end of U30 is also connected to the second ends of capacitor C1, resistor R3 and resistor R2 respectively, as well as the N line (Neutral Line, neutral line).

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

[0173] U29 can convert the mains power into a voltage of 24V.

[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, 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 connected to ground through resistor R19, pin 3 of U32 is also connected to ground through resistor R24, pin 8 of U32 is connected to the output end through inductor L2, pin 8 of U32 is also connected to ground through D1, pins 7 and 9 of U32 are connected to ground, pin 6 of U32 is connected to ground through capacitor C28, pin 5 of U32 is connected to ground through resistor R21, and the two ends of capacitor C23 are connected to the output end and ground respectively, the two ends of capacitor C24 are connected to the output end and ground respectively, and the output end is connected to ground through resistors R17 and R21.

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

[0176] U29 is an isolated step-down power module, the input range of which is 85V-275VAC or 100V-370VDC, and the output is DC 24V. F25 is a fuse, and the design refers to the EMC application circuit of the High Cube HS-36W series data manual. See Figure 8 U32 is an LMR14050 device, which is a 40V, 5A step-down regulator with an integrated high-side MOSFET. The device has a wide input voltage range of 4V to 40V, and the adjustable switching frequency range of the regulator is wide. The device also has multiple protection features built-in: 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, etc. of the electronic components in each circuit diagram of the present application are only exemplary, and the resistance, capacitance, inductance, voltage, model, etc. of the electronic components are adjusted according to the actual situation in actual application, and the present application does not limit this.

[0178] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by a computer program instructing relevant hardware, 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 above-mentioned embodiment methods. Any reference to memory, storage, database or other medium used in the embodiments provided in the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), 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), etc.

[0179] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0180] The above embodiments only express several implementation manners of the present application, and the description is specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A monitoring system of an open zero sequence voltage loop, characterized by, The monitoring system of the open zero sequence voltage loop comprises at least one sub-monitoring module, different sub-monitoring modules are connected and monitor different zero sequence voltage loops; 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 bus voltage transformer secondary open delta winding; The first voltage relay module is connected in series with the first fuse module and then connected to a first end and a second end in the bus voltage transformer secondary open delta winding; The second voltage relay module is connected in series with the second fuse module and then connected to a third end and a fourth end in the bus voltage transformer secondary open delta winding; 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 connection points in the bus voltage transformer secondary open delta winding. The normally closed contact of the first voltage relay module and the second voltage relay module is connected with the measurement and control module; the first voltage relay module comprises a first relay; the second voltage relay module comprises a second relay; a first contact of the first relay is connected with a second end in a secondary opening triangular winding of a bus voltage transformer through a pin of a first wiring terminal, an eighth contact of the first relay is connected with a first end in the secondary opening triangular winding of the bus voltage transformer through a first fuse, a first protection resistor and another pin of the first wiring terminal in sequence; a sixth contact of the first relay is connected with the first voltage, and a seventh contact of the first relay is connected with the measurement and control module; the first relay is specifically used for, if a first associated line in a monitored zero sequence voltage loop exists a broken line, then the sixth contact and the seventh contact of the first relay are communicated, and the first voltage is output to the measurement and control module; the first relay is specifically used for, if the first associated line in the monitored zero sequence voltage loop does not exist the broken line, then the sixth contact and the fifth contact of the first relay are communicated, and the seventh contact of the first relay is not output; a first contact of the second relay is connected with a fourth end in the secondary opening triangular winding of the bus voltage transformer through a pin of a second wiring terminal, an eighth contact of the second relay is connected with a third end in the secondary opening triangular winding of the bus voltage transformer through a second fuse, a second protection resistor and another pin of the second wiring terminal in sequence; a sixth contact of the second relay is connected with the first voltage, and a seventh contact of the second relay is connected with the measurement and control module; the second relay is specifically used for, if a second associated line in the monitored zero sequence voltage loop exists a broken line, then the sixth contact and the seventh contact of the second relay are communicated, and the first voltage is output to the measurement and control module; the second relay is specifically used for, if the second associated line in the monitored zero sequence voltage loop does not exist the broken line, then the sixth contact and the fifth contact of the second relay are communicated, and the seventh contact of the second relay is not output; a third contact of the first relay is connected with a second voltage; a second contact of the first relay is connected with a first alarm module through a first alarm resistor and a third wiring terminal; the first relay is further used for, if the first associated line in the monitored zero sequence voltage loop exists the broken line, then the third contact and the second contact of the first relay are communicated, so that the first alarm module is triggered to alarm; a third contact of the second relay is connected with the second voltage; a second contact of the second relay is connected with a second alarm module through a second alarm resistor and a fourth wiring terminal; the second relay is further used for, if the second associated line in the monitored zero sequence voltage loop exists the broken line, then the third contact and the second contact of the second relay are communicated, so that the second alarm module is triggered to alarm. The first voltage relay module and the second voltage relay module are configured to monitor the wiring condition of the corresponding zero sequence voltage loop and output a feedback signal reflecting the actual wiring condition of the zero sequence voltage loop to the measurement and control module, wherein the actual wiring condition includes a disconnection and normality.

2. The monitoring system of open zero sequence voltage loops according to claim 1, characterized in that, Each sub-monitoring module further comprises 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 configured to control the corresponding alarm module to give an alarm prompt when the actual wiring condition of the zero sequence voltage loop is a disconnection.

3. The monitoring system of open zero sequence voltage loops according to claim 1, characterized in that, The monitoring system of the open zero sequence voltage loop further comprises a master control module connected to each sub-monitoring module. The master control module is configured to receive and respond to a specified monitoring instruction of a user to generate a monitoring start instruction for a target sub-monitoring module. The target sub-monitoring module is configured to start and monitor the wiring condition of the corresponding zero sequence voltage loop after receiving the monitoring start instruction.

4. The monitoring system of open zero sequence voltage loops according to claim 1, characterized in that, Each sub-monitoring module further comprises a first monitoring start module. The first monitoring start module is configured 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.

5. The monitoring system of open zero sequence voltage loop according to claim 1, characterized in that, Each sub-monitoring module further comprises a second monitoring start module. The second monitoring start module is configured 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.

6. The monitoring system of open zero sequence voltage loops according to claim 4, characterized in that, The first monitoring start module comprises 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 of the switch control unit, and the first pin 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 connected to the sixth contact of the first relay and the sixth contact of the second relay U7, respectively.

7. The monitoring system of open zero sequence voltage loops according to claim 1, characterized in that, The monitoring system of the open zero sequence voltage loop further comprises a master control module and a voltage monitoring module connected in an electrical manner, wherein different sub-monitoring modules are connected to different voltage monitoring modules. The master control module is configured to monitor 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 through the voltage monitoring module.

8. The monitoring system of open zero sequence voltage loops according to claim 3, characterized in that, The monitoring system of the open zero sequence voltage loop further comprises a display module connected to the master control module. The display module is configured to display selectable items corresponding to different sub-monitoring modules on a display screen, receive a selection operation of a user on the selectable items corresponding to a target sub-monitoring module, generate a corresponding specified monitoring instruction in response to the selection operation, and output the specified monitoring instruction to the master control module.

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