Circuit breaker three-phase inconsistency protection device and method

Abstract

The invention relates to a three-phase inconsistency protection device for a circuit breaker, and the device comprises a protection action logic module which is used for judging a three-phase inconsistency fault according to the load state or no-load state of the circuit breaker, and triggering a protection action; and the protection criterion abnormity alarm module is used for sending an alarm signal when the electrical quantity serving as the three-phase inconsistency protection judgment basis is abnormal. The invention further discloses a corresponding method. According to the three-phase inconsistent protection method and device, by distinguishing the load state and the no-load state and setting different protection criteria for the two states, the accuracy and reliability of three-phase inconsistent protection can be improved, and the fault rates of misoperation, operation rejection and the like are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of relay protection, and in particular to a three-phase inconsistency protection device and method for a 220kV circuit breaker. Background Art

[0002] The switching mechanism of circuit breakers with voltage levels of 220kV and above is phase-by-phase operation, and there is a possibility that the three phases of the circuit breaker are inconsistent (one or two phases are in the closed state, and the other two phases or one phase are in the open state).

[0003] The three-phase inconsistency of the circuit breaker is an abnormal operating state, so the circuit breaker protection of 220kV and above voltage levels is equipped with three-phase inconsistency protection (not full-phase protection). When the three-phase inconsistency of the circuit breaker occurs, the three-phase inconsistency protection will be activated, the closing phase of the circuit breaker will be tripped, and the three-phase inconsistency state will be ended.

[0004] At present, there are two ways to judge the inconsistency of three phases of circuit breaker, one is to judge in the circuit breaker mechanism box, and the other is to judge on the relay protection device. There are certain differences in the specific judgment criteria of the above two judgment methods.

[0005] The judgment logic of the three-phase inconsistency protection in the circuit breaker mechanism box is: the normally open auxiliary contacts and the normally closed auxiliary contacts of the three-phase switch are connected to the protection circuit in parallel first and then in series; when the circuit breaker has a three-phase inconsistency state, the normally open auxiliary contact parallel circuit and the normally open auxiliary contact parallel circuit will be connected at the same time, and the series circuit of the two will also be connected. At this time, it is judged as a three-phase inconsistency state.

[0006] The problem with the above judgment logic is that when any of the six switch auxiliary contacts in the above circuit fails, it may lead to misjudgment or missed judgment of three-phase inconsistency, which in turn leads to malfunction or refusal of the three-phase inconsistency protection.

[0007] The judgment logic of the three-phase inconsistency protection realized by the relay protection device is: the judgment of the switch position is not limited to its auxiliary contacts, but also judged by the switch current. Only when the normally closed auxiliary contacts of the switch are connected and there is no current in the switch, the switch is judged to be in the open position, otherwise the switch is considered to be in the closed position. At the same time, the negative sequence current and zero sequence current blocking logic are designed; after the blocking logic is put into operation, in addition to judging the switch position by the state of the switch auxiliary contacts and whether the switch has current, the three-phase inconsistency protection can only be activated if the negative sequence current or zero sequence current of the three-phase switch exceeds the set value. In order to prevent the three-phase inconsistency protection from malfunctioning when the normally closed auxiliary contacts of the switch fail, the following blocking conditions are set: when the normally closed auxiliary contacts of a certain phase switch are closed and the switch has current, it is judged that the normally closed auxiliary of the switch is abnormal and the three-phase inconsistency protection is blocked.

[0008] After adding switch current criterion, zero-sequence current criterion and negative-sequence current criterion to the above judgment logic, it can avoid the problem of three-phase inconsistency protection misoperation or refusal to operate due to switch auxiliary contact failure. However, it also brings new shortcomings, as follows:

[0009] First, if the negative-sequence current or zero-sequence current blocking function is activated, if the switch is in the "no-load" state during operation (i.e. the switch is in the closed position and the load current is zero), the three-phase currents are all zero, and the negative-sequence current and zero-sequence current are also zero. At this time, the blocking release conditions of the negative-sequence current and zero-sequence current cannot be met, and the three-phase inconsistency protection will remain in the blocking state and lose its function.

[0010] Secondly, even if the negative sequence current or zero sequence current blocking function is exited and only the open and close auxiliary contacts and current judgment criteria are retained, the protection function of the switch in the no-load state is still defective; because the three-phase current is always zero, the state of the three-phase switch will be completely judged by the state of the auxiliary contacts; and the existing relay protection device only uses the normally closed auxiliary contacts of the switch to judge the switch position; this shows that once the normally closed auxiliary contacts of the switch fail, the protection device will misjudge the actual position of the switch and cause the protection to malfunction or refuse to operate;

[0011] Third, when a switch in a normal load state (i.e. the switch is in the closed position and the load current is not zero) has three-phase inconsistency and is accompanied by a failure of the normally closed auxiliary contacts of the switch, the locking condition "the normally closed auxiliary contact of a phase switch is closed and there is current in the switch" may be met. At this time, the three-phase inconsistency protection is locked, which will cause the protection to fail to operate. Summary of the invention

[0012] The technical problem to be solved by the present invention is to provide a three-phase inconsistency protection device and method for a circuit breaker, so as to improve the accuracy and reliability of the three-phase inconsistency protection and reduce the failure rate of false operation and refusal to operate.

[0013] As one aspect of the present invention, a circuit breaker three-phase inconsistency protection device is provided, comprising:

[0014] The protection action logic module is used to judge the three-phase inconsistency fault according to the load state or no-load state of the circuit breaker and trigger the protection action;

[0015] The protection judgment abnormal alarm module is used to send out an alarm signal when the electrical quantity used as the judgment basis for the three-phase inconsistency protection is abnormal.

[0016] Preferably, the protection action logic module further includes:

[0017] Three-phase inconsistent starting module, used to determine whether the circuit breaker is in a three-phase inconsistent starting state;

[0018] The three-phase inconsistency action module is used to determine whether to execute the three-phase inconsistency protection action after the three-phase inconsistency starting conditions are met.

[0019] Preferably, the three-phase inconsistent starting module further comprises:

[0020] The no-load state judgment unit is used to judge whether the circuit breaker is in a no-load state. When the three-phase currents of the switch are all zero, it is judged that the switch is in a no-load state;

[0021] The no-load three-phase inconsistency judgment unit is used to judge whether the three phases are consistent when the circuit breaker is in the no-load state. It uses whether the line has pressure as an auxiliary judgment criterion; it judges whether the three-phase switch states are all in the open position or in the closed position, and uses the judgment result of each phase switch position as the input end. When the three-phase switch positions are inconsistent, an inconsistent signal is output;

[0022] The protection input judgment unit is used to judge whether the three-phase inconsistency protection function has been put into operation; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation;

[0023] A load state judgment unit, used to judge whether the circuit breaker is in a load state;

[0024] A load three-phase inconsistency judgment unit is used to judge whether the three phases are consistent when the circuit breaker is in a load state, and uses the switch current as an auxiliary judgment criterion;

[0025] The no-load state judgment unit, the no-load three-phase inconsistency judgment unit and the protection input judgment unit jointly act on the three-phase inconsistency starting judgment under the no-load state;

[0026] The load state judgment unit, the load three-phase inconsistency judgment unit and the protection input judgment unit work together to judge the three-phase inconsistency starting under the load state.

[0027] Preferably, the three-phase inconsistency action module further comprises:

[0028] The three-phase inconsistency action condition module is used to determine whether the action conditions of the three-phase inconsistency protection are met;

[0029] The three-phase inconsistency action delay module is used to execute the three-phase inconsistency protection action after a preset delay after the three-phase inconsistency action conditions are met.

[0030] Preferably, the protection action logic module further includes:

[0031] The current blocking logic unit is used to further improve the reliability of the three-phase inconsistency protection action under load conditions, including zero-sequence current criterion, negative-sequence current criterion and current blocking input criterion;

[0032] Among them, the zero-sequence current criterion is used to meet the release condition of the zero-sequence current lockout when the measured zero-sequence current of the switch exceeds the set threshold;

[0033] The negative sequence current criterion is used to meet the release condition of the negative sequence current lockout when the measured negative sequence current of the switch exceeds the set threshold.

[0034] Preferably, the protection criterion abnormal alarm module further comprises:

[0035] A switch auxiliary contact abnormal alarm module is used to send out an alarm signal when the switch auxiliary contact state is abnormal;

[0036] A switch current abnormality alarm module is used to send out an alarm signal when the switch current state is abnormal;

[0037] The line voltage abnormality alarm module is used to send out an alarm signal when the line voltage state is abnormal.

[0038] Accordingly, as another aspect of the present invention, a circuit breaker three-phase inconsistency protection method is also provided, which is implemented by the above-mentioned device, and the method at least comprises the following steps:

[0039] Step S1, judging a three-phase inconsistency fault according to a load state or an unloaded state of the circuit breaker, and triggering a protection action;

[0040] Step S2, sending out an alarm signal through the protection criterion abnormal alarm module when an abnormality occurs in the electrical quantity serving as the basis for judging the three-phase inconsistency protection, including: when the state of the switch auxiliary contact is abnormal, sending out an alarm signal through the switch auxiliary contact abnormal alarm module; when the state of the switch current is abnormal, sending out an alarm signal through the switch current abnormal alarm module; when the state of the line voltage is abnormal, sending out an alarm signal through the line voltage abnormal alarm module.

[0041] Preferably, the step S1 further comprises:

[0042] Step S10, determining whether the circuit breaker is in a three-phase inconsistent starting state through a three-phase inconsistent starting module;

[0043] Step S11, after the three-phase inconsistency starting condition is met, the three-phase inconsistency action module determines whether to execute the three-phase inconsistency protection action.

[0044] Preferably, the step S10 further comprises:

[0045] Step S100, judging whether the circuit breaker is in a no-load state by a no-load state judging unit, and judging that the switch is in a no-load state when the three-phase currents of the switch are all zero;

[0046] Step S101, when the circuit breaker is in a no-load state, the no-load three-phase inconsistency judgment unit determines whether the three phases are consistent, which determines whether the switch states of the three phases are all in the open position or in the closed position, and uses the judgment result of the switch position of each phase as an input end, and outputs an inconsistent signal when the switch positions of the three phases are inconsistent;

[0047] Step S102, judging whether the three-phase inconsistency protection function has been put into operation by the protection input judgment unit; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation;

[0048] Step S103, determining whether the circuit breaker is in a load state by a load state determination unit;

[0049] Step S104, when the circuit breaker is in a load state, determining whether the three phases are consistent through a load three-phase inconsistency determination unit;

[0050] Among them, the three-phase inconsistent starting judgment under no-load state is jointly completed by the no-load state judgment unit, the no-load three-phase inconsistency judgment unit and the protection input judgment unit; the three-phase inconsistent starting judgment under load state is jointly completed by the load state judgment unit, the load three-phase inconsistency judgment unit and the protection input judgment unit.

[0051] Preferably, the step S11 further comprises:

[0052] Step S110, judging whether the action condition of the three-phase inconsistency protection is met through the three-phase inconsistency action condition module;

[0053] Step S111, after the three-phase inconsistency action condition is met, the three-phase inconsistency action delay module performs the three-phase inconsistency protection action after a preset delay.

[0054] The implementation of the present invention has the following beneficial effects:

[0055] The present invention provides a three-phase inconsistency protection device and method for a circuit breaker, which distinguishes between load and no-load states and sets different protection criteria for the two states. For no-load switches, since the three-phase currents are all zero, the current criterion cannot be used, so whether the line has voltage is used as an auxiliary criterion. For load switches, the traditional current criterion can be used, thereby improving the accuracy and reliability of the three-phase inconsistency protection.

[0056] Secondly, by adding the switch no-load state judgment logic and using whether the line has pressure as an auxiliary judgment criterion for the no-load switch state, the problem of false operation or refusal to operate in the no-load state is avoided.

[0057] In addition, by adding protection criterion abnormal alarm logic, an alarm signal can be issued in time when the electrical quantity (such as switch auxiliary contacts, switch current, line voltage, etc.) is abnormal, prompting the operation and maintenance personnel to handle it, thereby improving the safety and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments of the present invention or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0059] Figure 1 A schematic structural diagram of an embodiment of a three-phase inconsistency protection device for a circuit breaker is provided for the present invention;

[0060] Figure 2 for Figure 1 The structural diagram of the protection action logic module;

[0061] Figure 3 for Figure 2 Structural diagram of the three-phase inconsistent starting module;

[0062] Figure 4 for Figure 2 The structural diagram of the three-phase inconsistency action module;

[0063] Figure 5 for Figure 1 The structural diagram of the abnormal alarm module of the protection criterion;

[0064] Figure 6 It is a logic diagram for realizing a protection action logic module in a specific example of the present invention;

[0065] Figure 7 A logic diagram of an implementation of a protection criterion abnormal alarm module in a specific example of the present invention;

[0066] Figure 8 The present invention provides a main process diagram of an embodiment of a circuit breaker three-phase inconsistency protection method. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0068] like Figure 1 FIG. 1 is a schematic diagram showing a structure of a three-phase inconsistency protection device for a circuit breaker according to an embodiment of the present invention; and FIG. Figures 2 to 5 As shown, in this embodiment, the circuit breaker three-phase inconsistency protection device at least includes:

[0069] The protection action logic module 1 is used to judge the three-phase inconsistency fault according to the load state or no-load state of the circuit breaker and trigger the protection action;

[0070] The protection criterion abnormal alarm module 2 is used to send out an alarm signal when an electrical quantity serving as a basis for judging the three-phase inconsistency protection is abnormal.

[0071] like Figure 2 As shown, in a specific example, the protection action logic module 1 further includes:

[0072] A three-phase inconsistent starting module 10 is used to determine whether the circuit breaker is in a three-phase inconsistent starting state;

[0073] A three-phase inconsistency action module 11 is used to determine whether to execute a three-phase inconsistency protection action after the three-phase inconsistency starting condition is met;

[0074] The current blocking logic unit 12 is used to further improve the reliability of the three-phase inconsistency protection action under load conditions, including a zero-sequence current criterion, a negative-sequence current criterion, and a current blocking input criterion;

[0075] Among them, the zero-sequence current criterion is used to meet the release condition of the zero-sequence current lockout when the measured zero-sequence current of the switch exceeds the set threshold;

[0076] The negative sequence current criterion is used to meet the release condition of the negative sequence current lockout when the measured negative sequence current of the switch exceeds the set threshold.

[0077] like Figure 3 As shown, in a specific example, the three-phase inconsistent starting module 10 further includes:

[0078] The no-load state judgment unit 100 is used to judge whether the circuit breaker is in a no-load state. When the three-phase currents of the switch are all zero, it is judged that the switch is in a no-load state;

[0079] The no-load three-phase inconsistency judgment unit 101 is used to judge whether the three phases are consistent when the circuit breaker is in a no-load state, and whether the line has pressure is used as an auxiliary judgment criterion; it judges whether the three-phase switch states are all in the open position or in the closed position, and uses the judgment result of each phase switch position as an input end, and outputs an inconsistent signal when the three-phase switch positions are inconsistent;

[0080] The protection input judgment unit 102 is used to judge whether the three-phase inconsistency protection function has been put into operation; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation, and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation;

[0081] A load state determination unit 103, used to determine whether the circuit breaker is in a load state;

[0082] A load three-phase inconsistency judgment unit 104, used to judge whether the three phases are consistent when the circuit breaker is in a load state, and uses the switch current as an auxiliary judgment criterion;

[0083] The no-load state judgment unit 100, the no-load three-phase inconsistency judgment unit 101 and the protection input judgment unit 102 act together to judge the three-phase inconsistency starting under the no-load state;

[0084] The load state judgment unit 103, the load three-phase inconsistency judgment unit 104 and the protection input judgment unit 102 work together to judge the three-phase inconsistency starting under the load state.

[0085] like Figure 4 As shown, in a specific example, the three-phase inconsistency action module 11 further includes:

[0086] The three-phase inconsistency action condition module 110 is used to determine whether the action condition of the three-phase inconsistency protection is met;

[0087] The three-phase inconsistency action delay module 111 is used to perform a three-phase inconsistency protection action after a preset delay after the three-phase inconsistency action condition is met.

[0088] like Figure 5 As shown, in a specific example, the protection criterion abnormal alarm module 2 further includes:

[0089] A switch auxiliary contact abnormality alarm module 20, used to send out an alarm signal when the switch auxiliary contact state is abnormal;

[0090] The switch current abnormality alarm module 21 is used to send out an alarm signal when the switch current state is abnormal;

[0091] The line voltage abnormality alarm module 22 is used to send out an alarm signal when the line voltage state is abnormal.

[0092] In order to further understand the present invention, the following Figure 6 and Figure 7 A specific example is given to illustrate.

[0093] The circuit breaker three-phase inconsistency protection device involved in the present invention is a three-phase inconsistency protection implemented by a relay protection device, and its protection logic includes two parts: protection action logic and protection criterion abnormal alarm logic. Among them, the protection action logic module 1 implements the protection action logic, and the protection criterion abnormal alarm module 2 is used to implement the protection criterion abnormal alarm logic.

[0094] in, Figure 6 The following is a logic diagram showing the implementation of the protection action logic module 1 in a specific example of the present invention;

[0095] The protection action logic is divided into two parts: three-phase inconsistency starting logic and three-phase inconsistency action logic, which are implemented by three-phase inconsistency starting module 10 and three-phase inconsistency action module 11 respectively.

[0096] The three-phase inconsistent starting logic includes two parts: the three-phase inconsistent starting logic under the no-load state of the switch and the three-phase inconsistent starting logic under the load state. These two parts constitute Figure 6 That is, no matter whether the switch is in no-load state or load state, as long as the three-phase inconsistency protection starting criterion in the corresponding state is met, the three-phase inconsistency protection of the circuit breaker can be started correctly.

[0097] It can be understood that, in the present invention, in the judgment logic of starting the three-phase inconsistency protection of the circuit breaker, the working state of the circuit breaker is divided into two states: load and no-load, and different protection criteria are set for the two working states.

[0098] This is because, in order to prevent the failure of the normally closed auxiliary contact of the circuit breaker from causing the protection to misjudge the switch position, thereby causing the three-phase inconsistency protection to malfunction or refuse to operate, the traditional relay protection technology introduces the switch current as an auxiliary criterion, which is used together with the circuit breaker normally closed auxiliary contact criterion to determine the switch position. However, the traditional technology does not take into account that the switch may operate in a load state or a no-load state, nor does it formulate different protection criteria for these two working states. This results in the three-phase current being zero when the switch is in a no-load state. Once the normally closed auxiliary contact of the switch fails at this time (not corresponding to the primary state of the switch), the protection device may misjudge the switch position, thereby causing the three-phase inconsistency protection to malfunction or refuse to operate. The present invention formulates different inconsistency protection starting logic criteria for the load and no-load states of the switch, which can effectively avoid the occurrence of the above problems.

[0099] In the three-phase inconsistency starting module 10 provided by the present invention, the three-phase inconsistency starting logic in the no-load state of the switch includes three parts: switch no-load state judgment logic, no-load switch three-phase inconsistency judgment logic and three-phase inconsistency protection input judgment logic. The above three parts of logic together constitute the three input terminals of "AND gate 2". That is, when the above three parts of judgment logic are satisfied at the same time, the protection device will determine that the switch is in the no-load state and a three-phase inconsistency fault occurs, and the three-phase inconsistency protection is started at this time.

[0100] The switch no-load state judgment logic corresponding to the no-load state judgment unit 100 is that when the three-phase currents of the switch are all zero, the switch is considered to be in a no-load state, and the judgment result is output through the "AND gate 4". Among them, the three-phase current of the switch can be obtained through the original switch current secondary circuit of the relay protection device, and by setting an appropriate threshold, it is used as the judgment basis for its "current" and "no current".

[0101] The no-load switch three-phase inconsistency judgment logic corresponding to the no-load three-phase inconsistency judgment unit 101 is to judge whether the three-phase switch states are all in the open position or all in the closed position, and use the judgment result of each phase switch position as the input end of "XOR gate 5". When the three-phase switch positions are the same (all in the open position or all in the closed position), the outputs of "AND gate 6" to "AND gate 8" are all 1 (the three-phase switches are all in the open position) or all 0 (the three-phase switches are all in the closed position), and the output of "XOR gate 5" is 0; when the three-phase switches are inconsistent, the outputs of "AND gate 6" to "AND gate 8" are both 1 and 0, and the output of "XOR gate 5" is 1.

[0102] Among them, the criterion for a phase switch being in the open state is that the normally closed auxiliary contact of the phase switch is closed (TWJ is 1) and the phase line has no pressure. If the above criteria are met at the same time, the phase switch is considered to be in the open state, otherwise the phase switch is considered to be in the closed state. Among them, the method of obtaining the state of the normally closed auxiliary contacts of each phase switch is the same as the traditional relay protection technology, and whether each phase line has pressure can be judged by connecting the output end of the original line live display locking device (installed on the line side) to the relay protection device in the present invention.

[0103] In the above criteria, in addition to the switch auxiliary contacts, other criteria are selected as auxiliary criteria for the switch position in order to avoid the protection device misjudging the switch position when the normally closed auxiliary contact of the switch fails (TWJ cannot correctly reflect the actual position of the switch), thereby causing the three-phase inconsistency protection to malfunction or refuse to operate. For no-load switches, since the three-phase currents are all zero, the switch current cannot be used as an auxiliary criterion, and whether the line has pressure must be used as an auxiliary criterion. In most cases, whether the no-load line has pressure depends on the switch state. Therefore, the above criteria can effectively determine the position of the switch in most cases, preventing the three-phase inconsistency protection from malfunctioning or refusing to operate when the switch is no-load.

[0104] The three-phase inconsistency protection input judgment logic corresponding to the protection input judgment unit 102 is that when the "three-phase inconsistency protection" hard pressure plate on the protection device is turned on, and the "three-phase inconsistency protection" control word in the protection device is set to 1, and the above two conditions are met at the same time, it is considered that the three-phase inconsistency protection function has been normally turned on.

[0105] It can be understood that in the present invention, a switch no-load state judgment logic is added; whether the line has pressure is used as an auxiliary criterion for the no-load switch state; and by connecting the output end of the line high-voltage energized display locking device to the protection device, the judgment of whether the line has pressure is achieved.

[0106] This is because the conventional technology does not perform different logical judgments according to different working states of the switch; the current auxiliary judgment criteria used in the conventional technology are not suitable for no-load switches, and the conventional technology does not use the line voltage as an auxiliary judgment criterion for the switch state; in the conventional technology, the acquisition of the line voltage value by the relay protection device is limited to phase A; this is because the way it obtains the line voltage value is through the secondary voltage circuit of the line voltage transformer, and the line voltage transformer is usually only installed on phase A; the present invention needs to obtain the voltage state of the three-phase line (pressure or no pressure), but does not care about the specific voltage value, so the output end of the original line high-voltage live locking device is connected to the relay protection device, and the judgment result of the original line high-voltage live locking device is directly used; in the conventional technology, the judgment result of the line high-voltage live locking device is mainly used in the anti-misoperation locking logic of the knife switch control circuit rather than in the protection judgment logic of the relay protection device, so the conventional technology does not connect the output end of the line high-voltage live locking device to the relay protection device.

[0107] The three-phase inconsistency starting logic under the switch load state described in the present invention includes three parts: switch load state judgment logic, load switch three-phase inconsistency judgment logic and three-phase inconsistency protection input judgment logic. The above three parts of logic together constitute the three input terminals of "AND gate 3". That is, when the above three parts of judgment logic are satisfied at the same time, the protection device will determine that the switch is in the load state and a three-phase inconsistency fault occurs, and the three-phase inconsistency protection is started at this time.

[0108] The switch load state judgment logic corresponding to the load state judgment unit 103 is that when any phase of the three-phase current of the switch is not zero, the switch is considered to be in a load state, and the judgment result is output through the "NOT gate 9". The specific implementation method is that when any phase of the three-phase current of the switch is not zero, the "AND gate 4" outputs 0, and after being inverted by the "NOT gate 9", it outputs 1, indicating that the switch is in a load state.

[0109] The load switch three-phase inconsistency judgment logic corresponding to the load three-phase inconsistency judgment unit 104 is to judge whether the three-phase switch states are all in the open position or all in the closed position, and use the judgment result of each phase switch position as the input end of the "XOR gate 10". When the three-phase switch positions are the same (all in the open position or all in the closed position), the outputs of "AND gate 11" to "AND gate 13" are all 1 (the three-phase switches are all in the open position) or all 0 (the three-phase switches are all in the closed position), and the output of "XOR gate 10" is 0; when the three-phase switches are inconsistent, the outputs of "AND gate 11" to "AND gate 13" are both 1 and 0, and the output of "XOR gate 10" is 1.

[0110] Among them, the criterion for a phase switch being in the open state is that the normally closed auxiliary contact of the phase switch is closed (TWJ is 1) and there is no current in the phase switch. If the above criteria are met at the same time, the phase switch is considered to be in the open state, otherwise it is considered to be in the closed state. Among them, the acquisition method of the normally closed auxiliary contact state of each phase switch is the same as the traditional relay protection technology. The three-phase current of the switch can be obtained through the original switch current secondary circuit of the relay protection device, and by setting an appropriate threshold, it is used as the judgment basis for "current" and "no current".

[0111] Among the above criteria, the selection of other criteria as auxiliary criteria for switch position in addition to the switch auxiliary contact is to avoid the protection device misjudging the switch position when the normally closed auxiliary contact of the switch fails (TWJ cannot correctly reflect the actual position of the switch), thereby causing the three-phase inconsistency protection to malfunction or refuse to operate. For load switches, the switch current can be used as an auxiliary criterion. Since the switch current is taken from the original current secondary circuit of the relay protection device, it belongs to the traditional technology of relay protection and has higher reliability than the line high-voltage live display locking device. That is, for load lines, the traditional current criterion can be used, and its reliability is higher than that of the voltage criterion as an auxiliary criterion for judging the switch position.

[0112] The three-phase inconsistency protection activation judgment logic is the same as the judgment logic in the protection activation judgment unit 102 described above, and will not be repeated here.

[0113] It can be understood that in the present invention, the switch load state judgment logic is added, and the application scope of the switch position judgment criterion in the traditional technology is narrowed to the working state of "switch load", thereby improving the accuracy of the switch position judgment and avoiding the false operation or refusal of the three-phase inconsistency protection due to incorrect switch position judgment.

[0114] The three-phase inconsistency action logic of the present invention is implemented by a three-phase inconsistency action module 11, which includes two parts: a three-phase inconsistency action condition and a three-phase inconsistency action delay.

[0115] The three-phase inconsistency action condition corresponding to the three-phase inconsistency action condition module 110 includes two parts: the three-phase inconsistency action condition under the no-load state of the switch and the three-phase inconsistency action condition under the load state. These two parts respectively constitute Figure 6 That is, no matter the switch is in no-load state or load state, as long as the three-phase inconsistency protection action conditions in the corresponding state are met, the three-phase inconsistency protection of the circuit breaker can act correctly after a delay.

[0116] The three-phase inconsistency action condition in the no-load state of the switch is the same as the three-phase inconsistency starting logic in the no-load state of the switch. That is, when the switch satisfies the three-phase inconsistency starting logic in the no-load state, it will also meet the three-phase inconsistency action condition. The specific implementation method is to use the common criterion of the two as the input end of "AND gate 2", and use the output end of "AND gate 2" as the input end of "OR gate 1" and "OR gate 14" at the same time.

[0117] The three-phase inconsistency action condition under the switch load state includes two parts: the three-phase inconsistency starting logic under the switch load state and the current blocking logic. These two parts constitute Figure 6 That is, the switch must simultaneously meet the three-phase inconsistency starting criterion and the current blocking release criterion under load to meet the three-phase inconsistency action condition.

[0118] The three-phase inconsistent starting logic under the switch load state is as described above and will not be repeated here. The judgment result is used as the input end of "OR gate 1" in the three-phase inconsistent starting logic and the input end of "AND gate 15" in the three-phase inconsistent action logic through the input end of "AND gate 3".

[0119] For switches under load, the purpose of introducing current blocking logic is to further improve the reliability of the three-phase inconsistency protection action of the switch under load.

[0120] The current blocking logic corresponding to the current blocking logic unit 12 of the present invention comprises three parts: zero-sequence current criterion, negative-sequence current criterion and current blocking input criterion. These three parts together constitute the input end of the "OR gate 16".

[0121] Among them, the zero-sequence current criterion is that when the measured zero-sequence current of the switch exceeds the set threshold, and the three-phase inconsistency protection is normally put into operation through the zero-sequence current locking function, the release condition of the zero-sequence current locking is met. At this time, "AND gate 17" and "OR gate 16" both output 1. If the load switch meets the three-phase inconsistency starting logic, "AND gate 3" also outputs 1, and then "AND gate 15" will also output 1, and the three-phase inconsistency protection can be activated after a delay.

[0122] Among them, the measured zero-sequence current 3I0 can be obtained by "external connection" or "self-production". The so-called "external connection" refers to directly obtaining the zero-sequence current from the neutral line of the three-phase CT on the current sampling plug-in of the protection device; the so-called "self-production" refers to calculating the phase sum of the secondary current of the three-phase switch, that is, calculating the zero-sequence current value according to the three-phase current value by calculation.

[0123] The zero-sequence current unlocking threshold 3I0_zd is a manually set protection setting and can be set through the protection device.

[0124] The three-phase inconsistency protection via zero-sequence current blocking function can be activated or deactivated by setting the "inconsistency via zero-sequence" control word in the protection device.

[0125] The negative sequence current criterion is that when the measured negative sequence current of the switch exceeds the set threshold, and the three-phase inconsistency protection is normally put into operation through the negative sequence current locking function, the release condition of the negative sequence current locking is met. At this time, both "AND gate 18" and "OR gate 16" output 1. If the load switch meets the three-phase inconsistency starting logic, "AND gate 3" also outputs 1, and "AND gate 15" will also output 1, and the three-phase inconsistency protection can be activated after a delay.

[0126] Among them, the measured negative sequence current I2 cannot be measured directly, and needs to be obtained through calculation based on the current value measured by the three-phase switch.

[0127] The negative sequence current unlocking threshold I2_zd is a manually set protection setting and can be set through the protection device.

[0128] The three-phase inconsistency protection via negative sequence current blocking function can be activated or deactivated by setting the "inconsistency via negative sequence" control word in the protection device.

[0129] The current blocking input criterion is to determine whether the two control words "inconsistency through zero sequence" and "inconsistency through negative sequence" are both set to 0. If the above control words are all set to 0, the "NOR gate 19" outputs 1, and the three-phase inconsistency protection does not perform current blocking judgment. The switch only needs to meet the three-phase inconsistency starting logic under load to meet the action condition. If the above control words are not all 0, the "NOR gate 19" outputs 0. At this time, it is necessary to meet the zero-sequence or negative-sequence current criterion that has been put into use to meet the protection action condition.

[0130] It is understandable that in the present invention, the application scope of the current blocking logic in the traditional technology is narrowed to the working state of "switch load", thereby improving the accuracy of the current blocking and avoiding the problem of the three-phase inconsistency protection of the switch being locked for a long time in the no-load state. This is because when the switch is in the no-load state, the three-phase currents are all zero, and the zero-sequence current and the negative-sequence current must also be zero, which cannot meet the release conditions of the current blocking. If the application scope of the current blocking logic is not limited to the working state of "switch load", the three-phase inconsistency protection of the no-load switch will be locked for a long time until it is converted to the load state.

[0131] The three-phase inconsistency action delay corresponding to the three-phase inconsistency action delay module 111 means that after the three-phase inconsistency action condition is met, the "OR gate 14" outputs 1 after a delay of t2, and the three-phase inconsistency protection is activated. Among them, t2 is a protection setting value that can be manually set.

[0132] After the three-phase inconsistency protection is activated, the protection device trips the three phases of the switch and locks the switch reclosing at the same time.

[0133] The function of the protection criterion abnormal alarm logic corresponding to the protection criterion abnormal alarm module 2 provided by the present invention is that when the electrical quantities used as the basis for judging the inconsistency of the three-phase of the circuit breaker, such as the switch auxiliary contacts, switch current and line voltage, are abnormal, the relay protection device can send out an "inconsistent protection criterion abnormal alarm" alarm signal to prompt the operation and maintenance personnel to handle it in time.

[0134] like Figure 7 As shown, it shows the implementation logic diagram of the protection criterion abnormal alarm module in a specific example of the present invention. The protection criterion abnormal alarm logic corresponding to the protection criterion abnormal alarm module 2 is divided into three parts: switch auxiliary contact abnormal alarm logic, switch current abnormal alarm logic and line voltage abnormal alarm logic. The above three parts of logic together constitute Figure 2 The three input terminals of "OR gate 1" in the protection device are as follows. That is, when any part of the above three parts of logic is met, the protection device will determine that there is an abnormality in the criterion of the three-phase inconsistency protection. At this time, after a delay of t1, the protection device will issue an "inconsistent protection criterion abnormality alarm" signal, but will not lock the three-phase inconsistency protection. Among them, t1 is a fixed value solidified in the protection program.

[0135] It can be understood that, in the present invention, the auxiliary contact abnormal alarm logic of the switch is added, and its function is to prevent the normally closed auxiliary contacts of the switch from being unable to reflect the real position of the switch due to secondary component failure (such as TWJ contact adhesion, TWJ contact jamming, etc.) when the switch is in a no-load or load state, which may cause the three-phase inconsistency protection to malfunction or refuse to operate; the line voltage abnormal alarm logic is added, and its function is to prevent the line high-voltage live display locking device from being abnormal when the switch is in a no-load state, resulting in an error in the voltage judgment as an auxiliary criterion for the switch position, and then causing an error in the position judgment of the no-load switch, and finally causing the three-phase inconsistency protection to malfunction or refuse to operate when the switch is in a no-load state; the protection The protection criterion abnormal alarm logic only outputs an alarm signal, and does not lock the three-phase inconsistency protection; this is because, in the protection action logic, the three-phase inconsistency starting logic and the three-phase inconsistency action logic are both based on multiple criteria to determine the switch position. A single switch auxiliary contact abnormality, switch current abnormality or line voltage abnormality will only lead to reduced protection reliability, and will not directly lead to protection malfunction or refusal to operate; in this case, if the three-phase inconsistency protection is directly locked, it may cause the protection to refuse to operate when a three-phase inconsistency fault occurs; therefore, the above logic can solve the problem in traditional technology that the three-phase inconsistency protection may refuse to operate when the switch has three-phase inconsistency under load and is accompanied by a fault in the normally closed auxiliary contact of the switch.

[0136] In the present invention, the switch auxiliary contact abnormal alarm logic corresponding to the switch auxiliary contact abnormal alarm module 20 is used to prevent the switch from being unable to reflect the true position of the switch due to secondary component failure (such as TWJ contact adhesion, TWJ contact jamming, etc.) when the switch is in a no-load or load state, which may cause the three-phase inconsistency protection to malfunction or refuse to operate.

[0137] The switch auxiliary contact abnormal alarm logic is composed of the auxiliary contact abnormal judgment criteria of the three-phase switch. The auxiliary contact abnormal judgment results of each phase switch are output through "XOR gate 4" to "XOR gate 6" respectively, and then the overall judgment result of the three-phase switch is output through "AND gate 2" and "NOT gate 3".

[0138] The method for judging the abnormality of the auxiliary contacts of each phase switch is to take the "exclusive OR" of the normally open auxiliary contacts (HWJ) and the normally closed auxiliary contacts (TWJ) of the phase switch. Under normal circumstances, when the switch is in the closed position, HWJ is 1 and TWJ is 0; when the switch is in the open position, HWJ is 0 and TWJ is 1. That is, under normal circumstances, no matter what state the switch is in, the output of the exclusive OR gate with TWJ and HWJ as input terminals is 1; when the switch has secondary component failures such as auxiliary contact adhesion or jamming, HWJ and TWJ may be both 1 or both 0. At this time, the exclusive OR gate outputs 0, indicating that the auxiliary contacts of the phase switch are abnormal.

[0139] When the auxiliary contact of any phase switch is abnormal, the XOR gate of that phase outputs 0, and "AND gate 2" also outputs 0, indicating that the auxiliary contact of the three-phase switch is abnormal. After the output result of "AND gate 2" is inverted, after a delay of t1, the alarm signal "inconsistent protection judgment abnormal alarm" is output.

[0140] It should be noted that there are many defects that cause the state of the switch auxiliary contacts to not correctly reflect the actual position of the switch, but they can be divided into two major categories:

[0141] The result of the defect is that a single auxiliary contact of the switch cannot correctly reflect the actual position of the switch, while other auxiliary contacts are working normally; for example, the normally closed auxiliary contact of the switch phase A is sticky or stuck, at this time only the A phase TWJ cannot reflect the switch position, while the A phase HWJ can reflect the switch position normally;

[0142] The result of the defect is that all the auxiliary contacts of a certain phase switch cannot correctly reflect the actual position of the switch; for example, the transmission rod between the primary mechanism of phase A and the secondary auxiliary contact of phase A of the switch is broken. At this time, the phase A switch can perform normal opening and closing operations, but the actual state after the operation cannot be transmitted to the auxiliary contacts and input into the relay protection device through the auxiliary contacts; in this case, phase A TWJ and phase A HWJ will always remain in the state before the fault, and cannot truly reflect the switch position as the switch position changes.

[0143] The switch auxiliary contact abnormal alarm logic can only respond to the first type of defects, but not the second type of defects.

[0144] It can be understood that in the present invention, the abnormal alarm logic of the switch auxiliary contacts is added, and the traditional technology does not have this logical function; the two types of defects that cause the switch auxiliary contacts to be unable to correctly reflect the true position of the switch are analyzed, and it is clarified that the abnormal alarm logic of the switch auxiliary contacts can only reflect the first type of defects.

[0145] The switch current abnormality alarm logic corresponding to the switch current abnormality alarm module 21 of the present invention has the following functions:

[0146] Prevent the switch from being loaded and causing the normally closed auxiliary contacts to fail to reflect the true position of the switch due to primary component failure (e.g. breakage of the transmission rod between the primary mechanism and the secondary auxiliary contacts), which may cause the three-phase inconsistency protection to malfunction or refuse to operate;

[0147] Prevent the switch from being unable to reflect the true position of the switch due to a fault in the normally closed auxiliary contacts (such as TWJ contacts sticking or jamming) when the switch is under load, which may cause the three-phase inconsistency protection to malfunction or refuse to operate.

[0148] The switch current abnormality alarm logic is composed of the current abnormality judgment criteria of the three-phase switch. The judgment results of the current abnormality judgment criteria of each phase switch are output through "AND gate 7" to "AND gate 9" respectively, and then the overall judgment result of the three-phase switch is output through "OR gate 10".

[0149] The method for judging the abnormal current of each phase switch is to take the "AND" of the normally closed auxiliary contact (TWJ) of the phase switch and the switch current judgment result. Under normal circumstances, when the switch is in the open position, the current must be zero, and when the switch is in the closed position, the current may be zero (no-load state) or may not be zero (load state). However, regardless of whether the switch is closed or open, the output result of the AND gate composed of TWJ and the switch current judgment criterion must be 0 under normal circumstances. If the output of the AND gate is 1, it means that the switch TWJ and the current judgment criterion are both 1, and it can be judged that the switch TWJ is abnormal (because it is generally impossible for the switch current to be 0, but the switch CT detects current).

[0150] When any phase switch TWJ is abnormal, the AND gate of that phase outputs 1, and "OR gate 10" also outputs 1, indicating that there is an abnormality in the TWJ of this group of three-phase switches. After a delay of t1, an alarm signal "inconsistent protection criterion abnormality alarm" is output.

[0151] The switch current abnormal alarm logic can respond to the second type of defects and some first type of defects of the switch under load.

[0152] It is understandable that in the present invention, two types of defects that cause the switch auxiliary contacts to fail to correctly reflect the true position of the switch are analyzed, and it is clarified that the switch current abnormality alarm logic in the traditional technology can only reflect the second type of defects and part of the first type of defects when the switch is under load. This is equivalent to narrowing the application scope of the switch current abnormality alarm logic in the traditional technology, and preventing the three-phase inconsistency protection from malfunctioning or refusing to operate due to the over-range application of the alarm logic.

[0153] The line voltage abnormality alarm logic corresponding to the line voltage abnormality alarm module 22 of the present invention has the following functions:

[0154] It can prevent the switch from being unable to reflect the true position of the switch due to primary component failure (such as breakage of the transmission rod between the primary mechanism of the switch and the secondary auxiliary contact) when the switch is in a no-load state, which may cause the three-phase inconsistency protection to malfunction or refuse to operate; it can prevent the switch from being unable to respond to the true position of the switch due to primary component failure (such as breakage of the transmission rod between the primary mechanism of the switch and the secondary auxiliary contact), which may cause the three-phase inconsistency protection to malfunction or refuse to operate.

[0155] The line voltage abnormality alarm logic is composed of the voltage abnormality judgment criteria of the three-phase line. The judgment results of the voltage abnormality judgment criteria of each phase line are output through "AND gate 11" to "AND gate 13" respectively, and then the overall judgment result of the three-phase switch is output through "OR gate 14".

[0156] The method for judging abnormal voltage of each phase line is to take "AND" of the normally open auxiliary contact (HWJ) of the phase line switch and the line no-voltage judgment result. Under normal circumstances, when the switch is in the closed position, the line must have pressure, and when the switch is in the open position, the line voltage may be zero (the switch on the opposite side of the line is in the open state) or may not be zero (the switch on the opposite side of the line is in the closed state). However, regardless of whether the switch is closed or open, the output result of the AND gate composed of HWJ and the line no-voltage judgment criterion must be 0 under normal circumstances. If the output of the AND gate is 1, it means that the switch HWJ and the line no-voltage judgment criterion are both 1, and it can be judged that the switch HWJ is abnormal or the line high-voltage live display locking device is faulty.

[0157] When any phase switch HWJ or the line high-voltage live display locking device is abnormal, the AND gate of the phase outputs 1, and the "OR gate 14" also outputs 1, indicating that there is an abnormality in the HWJ of the three-phase switch group or the line high-voltage live display locking device of the line is faulty. After a delay of t1, the alarm signal "inconsistent protection judgment abnormality alarm" is output.

[0158] The line voltage abnormal alarm logic can respond to the second type of defect of the switch in the no-load state and the defect of the high-voltage live display locking device.

[0159] It can be understood that in the present invention, a line voltage abnormality alarm logic is added, which is not available in conventional technologies. Two types of defects that cause the switch auxiliary contacts to be unable to correctly reflect the true position of the switch are analyzed, and it is clarified that the line voltage abnormality alarm logic can reflect the second type of defect when the switch is in a no-load state and the defect of the high-voltage live display locking device.

[0160] In summary, the protection criterion abnormal alarm logic described in the present invention can fully reflect the two types of defects of the switch in the no-load state and the load state. That is, no matter what state the switch is in, no matter what the reason, if the auxiliary contact of the switch cannot correctly reflect the actual position of the switch, the alarm logic described in the present invention can correctly send out an alarm signal to avoid incorrect operation of the three-phase inconsistency protection. However, the protection criterion abnormal alarm logic in the traditional technology can only reflect the second type of defect of the switch in the load state. That is, the traditional technology has the problem that the switch in certain states may cause the three-phase inconsistency protection to operate incorrectly due to certain reasons.

[0161] like Figure 8As shown, it shows a schematic diagram of the main process of an implementation of a three-phase inconsistency protection method for a circuit breaker provided by the present invention. In this embodiment, it adopts the above-mentioned Figures 1 to 7 The method is implemented by the device described, and the method comprises at least the following steps:

[0162] Step S1, judging a three-phase inconsistency fault according to a load state or an unloaded state of the circuit breaker, and triggering a protection action;

[0163] Step S2, sending out an alarm signal through the protection criterion abnormal alarm module when an abnormality occurs in the electrical quantity serving as the basis for judging the three-phase inconsistency protection, including: when the state of the switch auxiliary contact is abnormal, sending out an alarm signal through the switch auxiliary contact abnormal alarm module; when the state of the switch current is abnormal, sending out an alarm signal through the switch current abnormal alarm module; when the state of the line voltage is abnormal, sending out an alarm signal through the line voltage abnormal alarm module.

[0164] In a specific example, the step S1 further includes:

[0165] Step S10, determining whether the circuit breaker is in a three-phase inconsistent starting state through a three-phase inconsistent starting module;

[0166] Step S11, after the three-phase inconsistency starting condition is met, the three-phase inconsistency action module determines whether to execute the three-phase inconsistency protection action;

[0167] Step S12, further improving the reliability of the three-phase inconsistency protection action under load, including zero-sequence current criterion, negative-sequence current criterion and current blocking input criterion;

[0168] Among them, the zero-sequence current criterion is used to meet the release condition of the zero-sequence current lockout when the measured zero-sequence current of the switch exceeds the set threshold;

[0169] The negative sequence current criterion is used to meet the release condition of the negative sequence current lockout when the measured negative sequence current of the switch exceeds the set threshold.

[0170] In a specific example, the step S10 further includes:

[0171] Step S100, judging whether the circuit breaker is in a no-load state by a no-load state judging unit, and judging that the switch is in a no-load state when the three-phase currents of the switch are all zero;

[0172] Step S101, when the circuit breaker is in a no-load state, the no-load three-phase inconsistency judgment unit determines whether the three phases are consistent, which determines whether the switch states of the three phases are all in the open position or in the closed position, and uses the judgment result of the switch position of each phase as an input end, and outputs an inconsistent signal when the switch positions of the three phases are inconsistent;

[0173] Step S102, judging whether the three-phase inconsistency protection function has been put into operation by the protection input judgment unit; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation;

[0174] Step S103, determining whether the circuit breaker is in a load state by a load state determination unit;

[0175] Step S104, when the circuit breaker is in a load state, determining whether the three phases are consistent through a load three-phase inconsistency determination unit;

[0176] Among them, the three-phase inconsistent starting judgment under no-load state is jointly completed by the no-load state judgment unit, the no-load three-phase inconsistency judgment unit and the protection input judgment unit; the three-phase inconsistent starting judgment under load state is jointly completed by the load state judgment unit, the load three-phase inconsistency judgment unit and the protection input judgment unit.

[0177] In a specific example, the step S11 further includes:

[0178] Step S110, judging whether the action condition of the three-phase inconsistency protection is met through the three-phase inconsistency action condition module;

[0179] Step S111, after the three-phase inconsistency action condition is met, the three-phase inconsistency action delay module performs the three-phase inconsistency protection action after a preset delay.

[0180] For more details, please refer to and combine the above Figures 1 to 7 The description is not repeated here.

[0181] The implementation of the present invention has the following beneficial effects:

[0182] The present invention provides a three-phase inconsistency protection device and method for a circuit breaker, which distinguishes between load and no-load states and sets different protection criteria for the two states. For no-load switches, since the three-phase currents are all zero, the current criterion cannot be used, so whether the line has voltage is used as an auxiliary criterion. For load switches, the traditional current criterion can be used, thereby improving the accuracy and reliability of the three-phase inconsistency protection.

[0183] Secondly, by adding the switch no-load state judgment logic and using whether the line has pressure as an auxiliary judgment criterion for the no-load switch state, the problem of false operation or refusal to operate in the no-load state is avoided.

[0184] In addition, by adding protection criterion abnormal alarm logic, an alarm signal can be issued in time when the electrical quantity (such as switch auxiliary contacts, switch current, line voltage, etc.) is abnormal, prompting the operation and maintenance personnel to handle it, thereby improving the safety and stability of the system.

[0185] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0186] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0187] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A three-phase inconsistency protection device for a circuit breaker, characterized in that: include: The protection action logic module is used to judge the three-phase inconsistency fault according to the load state or no-load state of the circuit breaker and trigger the protection action; The protection judgment abnormal alarm module is used to send out an alarm signal when the electrical quantity used as the judgment basis for the three-phase inconsistency protection is abnormal.

2. The circuit breaker three-phase inconsistency protection device according to claim 1, characterized in that: The protection action logic module further includes: A three-phase inconsistent starting module is used to determine whether the circuit breaker is in a three-phase inconsistent starting state; The three-phase inconsistency action module is used to determine whether to execute the three-phase inconsistency protection action after the three-phase inconsistency starting conditions are met.

3. The circuit breaker three-phase inconsistency protection device according to claim 2, characterized in that: The three-phase inconsistent starting module further comprises: The no-load state judgment unit is used to judge whether the circuit breaker is in a no-load state. When the three-phase currents of the switch are all zero, it is judged that the switch is in a no-load state; The no-load three-phase inconsistency judgment unit is used to judge whether the three phases are consistent when the circuit breaker is in the no-load state. It uses whether the line has pressure as an auxiliary judgment criterion; it judges whether the three-phase switch states are all in the open position or in the closed position, and uses the judgment result of each phase switch position as the input end. When the three-phase switch positions are inconsistent, an inconsistent signal is output; The protection input judgment unit is used to judge whether the three-phase inconsistency protection function has been put into operation; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation; A load state judgment unit, used to judge whether the circuit breaker is in a load state; A load three-phase inconsistency judgment unit is used to judge whether the three phases are consistent when the circuit breaker is in a load state, and uses the switch current as an auxiliary judgment criterion; The no-load state judgment unit, the no-load three-phase inconsistency judgment unit and the protection input judgment unit jointly act on the three-phase inconsistency starting judgment under the no-load state; The load state judgment unit, the load three-phase inconsistency judgment unit and the protection input judgment unit work together to judge the three-phase inconsistency starting under the load state.

4. The circuit breaker three-phase inconsistency protection device according to claim 2, characterized in that: The three-phase inconsistency action module further includes: The three-phase inconsistency action condition module is used to determine whether the action conditions of the three-phase inconsistency protection are met; The three-phase inconsistency action delay module is used to execute the three-phase inconsistency protection action after a preset delay after the three-phase inconsistency action conditions are met.

5. The circuit breaker three-phase inconsistency protection device according to any one of claims 1 to 4, characterized in that: The protection action logic module further includes: The current blocking logic unit is used to further improve the reliability of the three-phase inconsistency protection action under load conditions, including zero-sequence current criterion, negative-sequence current criterion and current blocking input criterion; Among them, the zero-sequence current criterion is used to meet the release condition of the zero-sequence current lockout when the measured zero-sequence current of the switch exceeds the set threshold; The negative sequence current criterion is used to meet the release condition of the negative sequence current lockout when the measured negative sequence current of the switch exceeds the set threshold.

6. The circuit breaker three-phase inconsistency protection device according to claim 5, characterized in that: The protection criterion abnormal alarm module further comprises: A switch auxiliary contact abnormal alarm module is used to send out an alarm signal when the switch auxiliary contact state is abnormal; A switch current abnormality alarm module is used to send out an alarm signal when the switch current state is abnormal; The line voltage abnormality alarm module is used to send out an alarm signal when the line voltage state is abnormal.

7. A three-phase inconsistency protection method for a circuit breaker, which is implemented by using the device according to any one of claims 1 to 6, characterized in that: The method comprises at least the following steps: Step S1, judging a three-phase inconsistency fault according to a load state or an unloaded state of the circuit breaker, and triggering a protection action; Step S2, sending out an alarm signal through the protection criterion abnormal alarm module when an abnormality occurs in the electrical quantity serving as the basis for judging the three-phase inconsistency protection, including: when the state of the switch auxiliary contact is abnormal, sending out an alarm signal through the switch auxiliary contact abnormal alarm module; when the state of the switch current is abnormal, sending out an alarm signal through the switch current abnormal alarm module; when the state of the line voltage is abnormal, sending out an alarm signal through the line voltage abnormal alarm module.

8. The circuit breaker three-phase inconsistency protection method according to claim 7, characterized in that: The step S1 further comprises: Step S10, determining whether the circuit breaker is in a three-phase inconsistent starting state through a three-phase inconsistent starting module; Step S11, after the three-phase inconsistency starting condition is met, the three-phase inconsistency action module determines whether to execute the three-phase inconsistency protection action.

9. The circuit breaker three-phase inconsistency protection method according to claim 8, characterized in that: The step S10 further comprises: Step S100, judging whether the circuit breaker is in a no-load state by a no-load state judging unit, and judging that the switch is in a no-load state when the three-phase currents of the switch are all zero; Step S101, when the circuit breaker is in a no-load state, the no-load three-phase inconsistency judgment unit determines whether the three phases are consistent, which determines whether the switch states of the three phases are all in the open position or in the closed position, and uses the judgment result of the switch position of each phase as an input end, and outputs an inconsistent signal when the switch positions of the three phases are inconsistent; Step S102, judging whether the three-phase inconsistency protection function has been put into operation by the protection input judgment unit; when the "three-phase inconsistency protection" hard pressure plate on the protection device is put into operation and the "three-phase inconsistency protection" control word in the protection device is set to 1, it is considered that the three-phase inconsistency protection function has been normally put into operation; Step S103, determining whether the circuit breaker is in a load state by a load state determination unit; Step S104, when the circuit breaker is in a load state, determining whether the three phases are consistent through a load three-phase inconsistency determination unit; Among them, the three-phase inconsistent starting judgment under no-load state is jointly completed by the no-load state judgment unit, the no-load three-phase inconsistency judgment unit and the protection input judgment unit; the three-phase inconsistent starting judgment under load state is jointly completed by the load state judgment unit, the load three-phase inconsistency judgment unit and the protection input judgment unit.

10. The circuit breaker three-phase inconsistency protection method according to claim 8, characterized in that: The step S11 further comprises: Step S110, judging whether the action condition of the three-phase inconsistency protection is met through the three-phase inconsistency action condition module; Step S111, after the three-phase inconsistency action condition is met, the three-phase inconsistency action delay module performs the three-phase inconsistency protection action after a preset delay.

Images