阅读说明：本技术 抽水蓄能发电电动机的断路器失灵故障检测方法及装置 (Method and device for detecting failure fault of circuit breaker of pumped storage generator motor ) 是由 李伟 谭力铭 王义凯 尹项根 刘仁 高翔 乔健 徐雯 吕滔 刘锋 曹坦坦 张哲 于 2021-06-28 设计创作，主要内容包括：本说明书一个或多个实施例提供一种抽水蓄能发电电动机的断路器失灵故障检测方法及装置,在断路器失灵保护启动时,通过记忆电流判据,检测系统处于带负载状态或者轻载状态,在带负载状态下,根据相电流判据、负序电流判据和基波电压相量差判据,检测是否发生断路器失灵故障以及判定故障相；在轻载状态下,根据相电流判据、负序电流判据和三次谐波电压相量差判据,检测是否发生断路器失灵故障。本实施例能够利用不同判据,检测不同情况下是否发生GCB失灵故障,通过电压相量差判据,能够正确反映不同类型的GCB拒动情况,满足抽水蓄能发电电动机的运行要求。(One or more embodiments of the present disclosure provide a method and an apparatus for detecting a circuit breaker failure fault of a pumped storage generator motor, where when a circuit breaker failure protection is started, a detection system is in an on-load state or a light-load state by memorizing a current criterion, and in the on-load state, whether a circuit breaker failure fault occurs and a fault phase is determined according to a phase current criterion, a negative sequence current criterion, and a fundamental wave voltage phase difference criterion; and under a light load state, detecting whether the breaker failure fault occurs according to a phase current criterion, a negative sequence current criterion and a third harmonic voltage phase difference criterion. According to the embodiment, whether GCB failure faults occur under different conditions can be detected by using different criteria, the rejection conditions of different types of GCBs can be correctly reflected through the voltage component difference criterion, and the operation requirements of the pumped storage generator motor are met.)

1. The method for detecting the failure fault of the circuit breaker of the pumped storage generator motor is characterized by comprising the following steps of:

when the breaker failure protection is started, detecting that the system is in a loaded state or a light-load state through memory current criteria; the memory current is the current before the pumped storage generator motor fails;

under the state with load, detecting whether a breaker failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion;

and under the light load state, detecting whether the breaker failure fault occurs according to the phase current criterion, the negative sequence current criterion and the third harmonic voltage phase difference criterion.

2. The method of claim 1, wherein the detecting that the system is in a loaded state or a light loaded state by memorizing a current criterion comprises:

comparing the memory current with a memory current criterion setting value;

and if the memory current is larger than the memory current criterion setting value, judging that the system is in the loaded state, otherwise, judging that the system is in the light-load state.

3. The method of claim 1, wherein detecting whether a GCB fault has occurred and determining a faulty phase based on a phase current criterion, a negative sequence current criterion, and a fundamental voltage phase difference criterion in the loaded state comprises:

comparing the fundamental wave voltage phase difference of two sides of any phase of the circuit breaker with a fundamental wave voltage phase difference criterion setting value;

and if the fundamental wave voltage phase difference of any phase is smaller than the fundamental wave voltage phase difference criterion setting value, judging that the breaker failure fault occurs, and judging that the phase is a fault phase.

4. The method of claim 1, wherein detecting whether a circuit breaker failure fault occurs in the light load condition based on the phase current criterion, the negative sequence current criterion, and a third harmonic voltage phase difference criterion comprises:

comparing the third harmonic voltage phase difference of two sides of any phase of the circuit breaker with a third harmonic voltage phase difference criterion setting value;

and if the third harmonic voltage phase difference of any phase is smaller than the third harmonic voltage phase difference criterion setting value, judging that the GCB failure fault occurs.

5. The method of claim 1 or 3, further comprising:

under the loaded state, when GCB failure fault is detected, the loaded protection action is executed; the on-load protection action comprises:

after delaying the first time, the GCB does not work and protects the GCB, and the GCB is tripped again;

after the second time is delayed, the GCB does not work for protection, the GIS switch and the magnetic extinction switch are tripped, the pumped storage generator motor is stopped, the factory low-voltage side switch is tripped, and the electric brake is locked.

6. The method of claim 1 or 4, further comprising:

and under the light load state, when the GCB failure fault is detected, an alarm signal is output.

7. A circuit breaker failure fault detection device of a pumped storage generator motor is characterized by comprising:

the state judgment module is used for detecting whether the system is in a loaded state or a light-load state through memory current criteria when the breaker failure protection is started; the memory current is the current before the pumped storage generator motor fails;

the load detection module is used for detecting whether a breaker failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion in a load state;

and the light load detection module is used for detecting whether the breaker failure fault occurs or not according to the phase current criterion, the negative sequence current criterion and the third harmonic voltage phase difference criterion in a light load state.

8. The apparatus of claim 7,

the state judgment module is used for comparing the memory current with a memory current criterion setting value; and if the memory current is larger than the memory current criterion setting value, judging that the system is in the loaded state, otherwise, judging that the system is in the light-load state.

9. The apparatus of claim 7,

the load detection module is used for comparing the fundamental wave voltage phase difference of two sides of any phase of the circuit breaker with a fundamental wave voltage phase difference criterion setting value; and if the fundamental wave voltage phase difference of any phase is smaller than the fundamental wave voltage phase difference criterion setting value, judging that the breaker failure fault occurs, and judging that the phase is a fault phase.

10. The apparatus of claim 7,

the light load detection module is used for comparing the third harmonic voltage phase difference of two sides of any phase of the circuit breaker with a third harmonic voltage phase difference criterion setting value; and if the third harmonic voltage phase difference of any phase is smaller than the third harmonic voltage phase difference criterion setting value, judging that the breaker failure fault occurs.

Technical Field

One or more embodiments of the present disclosure relate to the field of hydroelectric engineering technologies, and in particular, to a method and an apparatus for detecting a failure fault of a circuit breaker of a pumped storage generator motor.

Background

When the pumped storage generator motor fails or the system is in an abnormal working condition, the GCB executes protection action to isolate the pumped storage generator motor from the system, so that the fault is removed, and the accident range is prevented from being enlarged.

The circuit breaker in normal operation is called circuit breaker failure because of the mechanical or electrical defect of the circuit breaker, and GCB failure causes the circuit breaker to fail to execute protection action. Therefore, how to accurately detect whether the GCB malfunctions is a critical issue to be solved.

Disclosure of Invention

In view of the above, an object of one or more embodiments of the present disclosure is to provide a method and an apparatus for detecting a failure fault of a circuit breaker of a pumped storage generator motor, which can accurately detect whether a GCB has a failure fault.

In view of the above, one or more embodiments of the present disclosure provide a method for detecting a circuit breaker failure of a pumped-storage generator motor, comprising:

when the breaker failure protection is started, detecting that the system is in a loaded state or a light-load state through memory current criteria; the memory current is the current before the pumped storage generator motor fails;

under the state with load, detecting whether a breaker failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion;

and under the light load state, detecting whether the breaker failure fault occurs according to the phase current criterion, the negative sequence current criterion and the third harmonic voltage phase difference criterion.

Optionally, the detecting that the system is in the loaded state or the light-load state by memorizing the current criterion includes:

comparing the memory current with a memory current criterion setting value;

and if the memory current is larger than the memory current criterion setting value, judging that the system is in the loaded state, otherwise, judging that the system is in the light-load state.

Optionally, in the loaded state, detecting whether a GCB failure fault occurs and determining a fault phase according to a phase current criterion, a negative sequence current criterion, and a fundamental wave voltage phase difference criterion, includes:

comparing the fundamental wave voltage phase difference of two sides of any phase of the circuit breaker with a fundamental wave voltage phase difference criterion setting value;

and if the fundamental wave voltage phase difference of any phase is smaller than the fundamental wave voltage phase difference criterion setting value, judging that the breaker failure fault occurs, and judging that the phase is a fault phase.

Optionally, in the light load state, detecting whether a breaker failure fault occurs according to the phase current criterion, the negative sequence current criterion, and the third harmonic voltage phase difference criterion, includes:

comparing the third harmonic voltage phase difference of two sides of any phase of the circuit breaker with a third harmonic voltage phase difference criterion setting value;

and if the third harmonic voltage phase difference of any phase is smaller than the third harmonic voltage phase difference criterion setting value, judging that the GCB failure fault occurs.

Optionally, the method further includes:

under the loaded state, when GCB failure fault is detected, the loaded protection action is executed; the on-load protection action comprises:

after delaying the first time, the GCB does not work and protects the GCB, and the GCB is tripped again;

after the second time is delayed, the GCB does not work for protection, the GIS switch and the magnetic extinction switch are tripped, the pumped storage generator motor is stopped, the factory low-voltage side switch is tripped, and the electric brake is locked.

Optionally, the method further includes:

and under the light load state, when the GCB failure fault is detected, an alarm signal is output.

This specification still provides a pump storage generator motor's circuit breaker failure fault detection device, includes:

the state judgment module is used for detecting whether the system is in a loaded state or a light-load state through memory current criteria when the breaker failure protection is started; the memory current is the current before the pumped storage generator motor fails;

the load detection module is used for detecting whether a breaker failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion in a load state;

and the light load detection module is used for detecting whether the breaker failure fault occurs or not according to the phase current criterion, the negative sequence current criterion and the third harmonic voltage phase difference criterion in a light load state.

Optionally, the state judgment module is configured to compare the memory current with a memory current criterion setting value; and if the memory current is larger than the memory current criterion setting value, judging that the system is in the loaded state, otherwise, judging that the system is in the light-load state.

Optionally, the load detection module is configured to compare a fundamental wave voltage component difference between two sides of any one phase of the circuit breaker with a fundamental wave voltage component difference criterion setting value; and if the fundamental wave voltage phase difference of any phase is smaller than the fundamental wave voltage phase difference criterion setting value, judging that the breaker failure fault occurs, and judging that the phase is a fault phase.

Optionally, the light load detection module is configured to compare a third harmonic voltage phase difference between two sides of any one phase of the circuit breaker with a third harmonic voltage phase difference criterion setting value; and if the third harmonic voltage phase difference of any phase is smaller than the third harmonic voltage phase difference criterion setting value, judging that the breaker failure fault occurs.

As can be seen from the above description, in the method and apparatus for detecting a breaker failure fault of a pumped storage generator motor according to one or more embodiments of the present disclosure, when the breaker failure protection is started, the detection system is in an on-load state or a light-load state by memorizing a current criterion, and in the on-load state, whether a breaker failure fault occurs and a fault phase are determined according to a phase current criterion, a negative sequence current criterion, and a fundamental voltage phase difference criterion, and in the light-load state, whether a breaker failure fault occurs is detected according to a phase current criterion, a negative sequence current criterion, and a third harmonic voltage phase difference criterion. According to the embodiment, whether GCB failure faults occur under different conditions can be detected by using different criteria, the rejection conditions of different types of GCBs can be correctly reflected through the voltage component difference criterion, and the operation requirements of the pumped storage generator motor are met.

Drawings

In order to more clearly illustrate one or more embodiments or prior art solutions of the present specification, the drawings that are needed in the description of the embodiments or prior art will be briefly described below, and it is obvious that the drawings in the following description are only one or more embodiments of the present specification, and that other drawings may be obtained by those skilled in the art without inventive effort from these drawings.

FIG. 1 is a schematic flow chart of a method according to one or more embodiments of the present disclosure;

FIG. 2 is a schematic flow chart of a method according to another embodiment of the present disclosure;

FIG. 3 is a block diagram of detection logic in accordance with one or more embodiments of the present disclosure;

fig. 4 is a graph of a simulation result of a difference in fundamental voltage phase at two sides of a GCB three-phase after normal operation when a single-phase ground fault of a stator occurs in a pumped storage generator motor under a loaded state according to one or more embodiments of the present disclosure;

fig. 5 is a graph showing simulation results of a difference in fundamental voltage phase at two sides of a single-phase GCB after rejection when a single-phase stator ground fault occurs in a pumped storage generator motor with load according to one or more embodiments of the present disclosure;

fig. 6 is a graph showing simulation results of the difference in fundamental voltage phase at two sides of a GCB phase after rejection when a single-phase ground fault of a stator occurs in a pumped storage generator motor under a loaded state according to one or more embodiments of the present disclosure;

fig. 7 is a graph showing simulation results of the difference in fundamental voltage phase at two sides of a pumped storage generator motor in accordance with one or more embodiments of the present disclosure after three phases of a GCB are rejected when a single-phase ground fault of a stator occurs in a loaded state of the motor;

fig. 8 is a graph showing simulation results of the difference in voltage phase of the fundamental waves at two sides of the pumped storage generator motor after the GCB normally operates when a single-phase ground fault of the stator occurs in a light load state of the pumped storage generator motor according to one or more embodiments of the present disclosure;

fig. 9 is a graph of a simulation result of a phase difference between third harmonic voltages at two sides of a pumped storage generator motor according to one or more embodiments of the present disclosure after a GCB normally operates when a stator single-phase ground fault occurs in a light load state;

FIG. 10 is a block diagram of an apparatus according to one or more embodiments of the disclosure;

FIG. 11 is a block diagram of an electronic device in accordance with one or more embodiments of the present disclosure.

Detailed Description

For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.

It is to be noted that unless otherwise defined, technical or scientific terms used in one or more embodiments of the present specification should have the ordinary meaning as understood by those of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in one or more embodiments of the specification is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

As described in the background art, the GCB failure protection is applied to trip other circuit breakers close to the failed GCB as soon as possible, and the fault is removed within a minimum range, so that the problem that the fault range is expanded by removing a remote circuit breaker by a remote backup protection action of an adjacent substation is avoided, and once the GCB has a failure fault, the fault cannot be removed as soon as possible, and the fault range is possibly expanded.

In the process of implementing the present disclosure, the applicant finds that the current criterion is adopted for the existing breaker failure protection, the traditional breaker failure starting element generally only has a three-phase overcurrent starting element, a zero-sequence current starting element and a negative-sequence current increment starting element, and the negative-sequence current and zero-sequence current criterion is adopted for the grid line breaker failure protection. Because the motor end of the pumped storage generator is connected with the delta/Y type transformer, zero sequence current cannot flow, and therefore the GCB failure protection adopts phase current and negative sequence current as criteria. The current criterion is an excess criterion, when the GCB failure protection is started, if the phase current and/or the negative sequence current exceed the setting value, the GCB failure fault is judged to occur, otherwise, the GCB is considered to be in normal action. However, when the GCB has single-phase failure, the protection cannot operate correctly because the equivalent zero-sequence impedance of the main transformer triangular winding is infinite and the phase current and the negative-sequence current are zero; when the circuit breaker failure protection is started due to the single-phase earth fault or the negative sequence overload fault of the stator, if the circuit breaker has a three-phase failure fault, the phase current and the negative sequence current may not reach the failure protection setting value, and the GCB failure fault cannot be judged. Therefore, the existing phase current and zero sequence current criterion cannot correctly reflect the GCB failure condition and cannot meet the operation requirement of the pumped storage generator motor unit.

In view of this, the method for detecting a failure fault of a circuit breaker of a pumped storage generator motor provided by the specification can correctly reflect the rejection condition of the GCB by using a reasonable and effective criterion, identify the failure fault of the GCB under different conditions, and on the basis, adopt effective GCB failure protection action to remove the fault in time, so that the operation requirement of a pumped storage generator motor unit can be met.

Hereinafter, the technical means of the present disclosure will be described in further detail with reference to specific examples.

As shown in fig. 1, one or more embodiments herein provide a method for detecting a circuit breaker failure of a pumped-storage generator motor, comprising:

s101: when the breaker failure protection is started, detecting that the system is in a loaded state or a light-load state through memory current criteria; the memory current is the current before the pumped storage generator motor fails;

in the embodiment, when the pumped storage generator motor fails or the system is in an abnormal working condition, the corresponding protection action outlet trips the three-phase GCB, and the GCB failure protection is started at the same time. When the breaker failure protection is started, whether the system is in a loaded state or a light-load state is detected through a memory current criterion, if the memory current is large, the system is judged to be in the loaded state before GCB removal, and if the memory current is small, the system is judged to be in the light-load state before GCB removal.

In some modes, when the pumped storage generator motor fails or the system is in an abnormal working condition, the action of protecting the outlet is executed, the GCB is tripped, the pumped storage generator motor is isolated from the system, and the GCB failure protection is started at the same time. The types of protection involved primarily in protecting the egress mode, including tripping the GCB and enabling GCB failsafe, include: differential protection, split phase lateral difference protection, generator turn-to-turn protection (lateral difference), generator phase-to-phase backup protection, stator ground protection, negative sequence overload protection and the like.

S102: under the loaded state, detecting whether a GCB failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion;

in this embodiment, when the memory current criterion is used to determine that the system is in a loaded state, the phase current criterion, the negative sequence current criterion, and the fundamental wave voltage phase difference criterion are used as the basis to determine whether a GCB failure fault occurs. Namely, a fundamental wave voltage phase difference criterion is added on the basis of a phase current criterion and a negative sequence current criterion, and whether a GCB failure fault occurs under a load state is comprehensively judged. In some modes, the loaded state of the system refers to a non-unloaded and light-loaded state that the system runs in a full-load or overload state.

The basis of adopting the fundamental wave voltage phasor difference criterion is that the fundamental wave voltage phasor difference exists due to the fact that the fundamental wave voltage phasors on two sides of the GCB are different for the correct action phase of the GCB; for the rejected phase of the GCB, the fundamental wave voltage phasors on the two sides of the rejected phase are approximately the same (theoretically the same), and the fundamental wave voltage phasor difference is approximately zero (theoretically the zero, actually the zero is not zero due to the influence of factors such as circuit breaker resistance and inconsistent TV characteristics).

S103: and under the light load state, detecting whether the GCB failure fault occurs according to a phase current criterion, a negative sequence current criterion and a third harmonic voltage phase difference criterion.

In this embodiment, the memory current criterion is used to determine whether the system is in a light load state, and whether a GCB failure fault occurs is determined based on a phase current criterion, a negative sequence current criterion, and a third harmonic voltage phase difference criterion. In some approaches, the light load state may include light load and no load states.

It is considered that the fundamental wave voltage phase difference criterion may cause malfunction in the light load state, and is not suitable for the light load state. And judging whether the GCB failure fault occurs or not according to whether the third harmonic voltage component difference on the two sides of the GCB is a small value close to zero or not. When the GCB normally operates, the third harmonic voltage phase difference of the three phases of the GCB is large, and when a GCB failure occurs, the third harmonic voltage phase difference of the three phases approaches zero.

According to the method for detecting the failure fault of the circuit breaker of the pumped storage generator motor, when the circuit breaker is started in failure protection, firstly, whether the system is in a loaded state or a light load state is judged through the memory current criterion, if the system is in the loaded state, whether the GCB failure fault occurs or not is detected by combining the fundamental wave voltage phase difference criterion on the basis of the phase current criterion and the negative sequence current criterion, and if the system is in the light load state, whether the GCB failure fault occurs or not is detected by combining the third harmonic voltage phase difference criterion on the basis of the phase current criterion and the negative sequence current criterion. The method of the embodiment can detect whether the GCB failure fault occurs under different conditions by using reasonable and effective criteria, and can correctly reflect the different types of GCB failure conditions through the voltage component difference criteria.

In some embodiments, the detecting that the system is in the loaded state or the light load state by memorizing the current criterion comprises:

comparing the memory current with a memory current criterion setting value;

if the memory current is larger than the memory current criterion setting value, judging that the system is in a loaded state, otherwise, judging that the system is in a light-load state.

In some ways, the memory current criterion can be expressed as:

wherein the content of the first and second substances,to memorize the current, I_memory·setThe setting value is judged for the memory current, and the setting can be carried out according to the actual running load current.

In some embodiments, detecting whether a GCB failure fault occurs and determining a faulted phase based on a phase current criterion, a negative sequence current criterion, and a fundamental voltage phase difference criterion under an on-load condition includes:

comparing the fundamental wave voltage phase difference of two sides of any phase of the GCB with a fundamental wave voltage phase difference criterion setting value;

if the fundamental wave voltage phase difference of any phase is smaller than the fundamental wave voltage phase difference criterion setting value, the GCB failure fault is judged to occur, and the phase is judged to be a fault phase.

In some modes, a certain load current exists in a loaded state, and when a GCB failure fault occurs, the GCB failure condition can be effectively reflected through the difference of the voltage quantities of fundamental waves on two sides of the GCB. In the three phases of the GCB, the fundamental wave voltage phase amounts on both sides of the correct operation phase are different from each other, and the difference is large, while the fundamental wave voltage phase amount difference on both sides of the operation-rejected phase (fault phase) is a small value close to 0. Based on this, a fundamental wave voltage phase difference criterion based on the fundamental wave voltage phase difference of the two sides of any phase of the circuit breaker is constructed and expressed as:

wherein the content of the first and second substances,is the magnitude of the fundamental voltage phase difference,that is to say that the first and second electrodes,this indicates the difference in fundamental wave voltage components on both sides of any of the phases a, B, and C of the GCB. Delta U_setA setting value is determined for the fundamental wave voltage phase difference, the setting value of the unbalanced voltage difference can be avoided according to field operation experience, and the setting value is higher than the unbalanced voltage difference.

The fundamental wave voltage phase difference criterion is an underquantity criterion, and after GCB failure protection is started, if the fundamental wave voltage phase difference of two sides of any phase of the GCB is smaller than the fundamental wave voltage phase difference criterion setting value, the phase can be judged to have GCB failure fault and is a fault phase. Various possible failure fault conditions of the GCB can be effectively identified by using a fundamental wave voltage phase difference criterion, and a failure fault phase can be accurately determined.

In some embodiments, detecting whether a GCB failure fault occurs based on a phase current criterion, a negative-sequence current criterion, and a third harmonic voltage phase difference criterion during a light load condition includes:

comparing the third harmonic voltage phase difference of two sides of any phase of the GCB with a third harmonic voltage phase difference criterion setting value;

and if the third harmonic voltage phase difference of any one phase is smaller than the third harmonic voltage phase difference criterion setting value, judging that the GCB failure fault occurs.

In the embodiment, in a light-load state, on the basis of a phase current criterion and a negative-sequence current criterion, a third harmonic voltage phase difference criterion is added to detect whether a GCB failure fault occurs.

Because of the structural characteristics of the rotor winding of the generator, certain third harmonic magnetic potential and magnetic density always exist, third harmonic components also exist in the phase voltage of the generator even under a light load state, and the third harmonic voltage is zero-sequence, so that third harmonic components do not exist in the system side voltage. It should be noted that, unlike the fundamental voltage, since the generator outlet-side transformer is of the Δ/Y type, as long as any one phase of the GCB fails, a third harmonic voltage is present on both sides of each phase.

When the pumped storage generator motor has an internal fault and needs to be tripped out of the GCB, when the GCB normally operates, the generator motor side has third harmonic voltage, but the load side does not contain the third harmonic voltage, and at the moment, the two sides of the GCB have third harmonic voltage quantity difference. Accordingly, if any one of the phases of the GCB is rejected, the difference in the voltage amounts of the third harmonics on both sides of the GCB becomes a small value close to 0. Based on the above, a third harmonic voltage phase difference criterion in a light load state is constructed, and is expressed as:

wherein the content of the first and second substances,is the magnitude of the third harmonic voltage component difference, whereinThat is to say that the first and second electrodes,this represents the difference in third harmonic voltage components on both sides of any of the phases a, B, and C of the GCB. Delta U_set.3The third harmonic voltage component difference is used as a setting value, the unbalanced voltage difference setting can be avoided according to field operation experience, and the setting value is higher than the unbalanced voltage difference. After the GCB failure protection is started, if the third harmonic voltage phase difference at two sides of the GCB is smaller than the third harmonic voltage phase difference criterion setting value, the GCB failure fault can be judged.

In some embodiments, the phase current criterion may be expressed as:

wherein the content of the first and second substances,is the effective value of the phase current phasor, I_ph·setThe phase current is used as a criterion setting value.

The negative sequence current criterion can be expressed as:

wherein the content of the first and second substances,is the effective value of the negative-sequence current phasor; i is_2·setAnd judging a setting value for the negative sequence current.

The current criterion is an excess criterion. Effective value of phase current phasor when GCB three-phase normal action is trippedAnd effective value of negative-sequence current phasorAll are zero, and the current criterion protection can not act. When any two phases of the GCB are refused to act, the current criterion protects the action and judges that the GCB fails. However, when the GCB has single-phase rejection or three-phase rejection, neither the negative-sequence current criterion nor the phase current criterion can correctly reflect the actual rejection of the GCB, and further detection needs to be performed according to an on-load state or a light-load state by combining the fundamental wave voltage phase difference criterion or the third harmonic wave phase difference.

In some embodiments, as shown in fig. 2 and 3, after the GCB failure is detected, a corresponding protection action is further performed. The method for detecting the circuit breaker failure fault of the pumped storage generator motor further comprises the following steps:

under the loaded state, when GCB failure fault is detected, the loaded protection action is executed; the on-load protection action includes:

after delaying the first time, the GCB does not work and protects the GCB, and the GCB is tripped again;

after the second time is delayed, the GCB does not work for protection, the GIS switch and the magnetic extinction switch are tripped, the pumped storage generator motor is stopped, the factory low-voltage side switch is tripped, and the electric brake is locked.

In this embodiment, when it is determined that a GCB failure fault occurs in an on-load state, it is known that other circuit breakers near the fault GCB need to trip as soon as possible according to the relay protection configuration rule of the transformer bank of the pumped storage generator motor, and the fault is removed within a minimum range, so that it is avoided that a far-back-up protection action of an adjacent substation removes a far-side circuit breaker to enlarge an accident range.

The method for detecting the circuit breaker failure fault of the pumped storage generator motor further comprises the following steps:

and under the light load state, when the GCB failure fault is detected, an alarm signal is output.

In the embodiment, when the GCB failure fault occurs in a light-load state, the GCB failure fault has little influence on the safe operation of the generator and the system under the light-load or no-load operation working condition, and the fault can be reminded through the alarm signal.

In some embodiments, to verify the effectiveness of the methods of the present description, a generator-transformer-load simulation model is built from a large pumped storage generator-motor group in a PSCAD/EMTDC software platform. The large-scale pumped storage generator motor adopts an 8-branch winding structure, each winding adopts a distributed equivalent circuit, each branch winding has 8 polar phase groups, and each polar phase group has 4 turns of coils. Rated voltage of the generator is 22kV, stator winding resistance/phase: 1.5m Ω, stator winding inductance/phase: 0.414mH, stator winding capacitance/phase: 4.19 uF. The number of pole pairs of the generator is 32, the total number of slots is 764, and the corresponding electrical angle of the slot pitch is 15 degrees. The fundamental wave voltage phase difference criterion setting value is set to be 30V, and the third harmonic voltage phase difference criterion setting value is set to be 5V.

And establishing a generator quasi-distribution parameter model for simulation verification based on PSCAD/EMTDC software. Assuming that the generator has stator single-phase metallic earth fault to start GCB failure protection, the A phase is set as the fault phase. Under the conditions of GCB normal action, single-phase rejection, two-phase rejection and three-phase rejection, the fundamental wave voltage phase difference of two sides of each phase is calculated. Under the conditions of GCB normal operation and three-phase refusal operation, the third harmonic voltage phase component difference of each phase of the GCB is calculated.

As shown in fig. 4 to 7, the fundamental voltage phase difference between both sides of each phase occurs when the GCB normally operates in the system loaded state, and the fundamental voltage phase difference between both sides of each phase occurs when a single-phase rejection, a two-phase rejection, or a three-phase rejection fault occurs in the GCB. Fig. 8 shows the difference in the fundamental voltage components on both sides of the GCB when the GCB is operating normally in a light system load state. Fig. 9 shows the difference in the third harmonic voltage phase amounts at both sides of each phase when the GCB is operating normally in the light system load state.

According to the simulation results of fig. 4-9, under the condition that the system is loaded, the fundamental wave voltage phase difference criterion can correctly reflect the GCB failure fault and can judge the fault phase; under the condition of light load of the system, the fundamental wave voltage phase difference criterion can be in misoperation, so that the fundamental wave voltage phase difference criterion needs to be locked under the condition of light load, and the GCB failure fault can be effectively reflected by using the third harmonic voltage phase difference criterion. Therefore, the GCB failure fault criterion (fundamental wave voltage phase difference criterion and third harmonic voltage phase difference criterion) based on the voltage quantity can effectively reflect the GCB failure fault, simultaneously provide a fault phase, meet the operation requirement of the pumped storage power generation motor unit, provide reference for a GCB failure protection criterion configuration method of a large pumped storage power generation motor, provide effective reference for a GCB failure protection improvement method of the pumped storage power generation motor unit, and provide technical reference for other generator GCB failure protection improvement methods.

It should be noted that the method of one or more embodiments of the present disclosure may be performed by a single device, such as a computer or server. The method of the embodiment can also be applied to a distributed scene and completed by the mutual cooperation of a plurality of devices. In such a distributed scenario, one of the devices may perform only one or more steps of the method of one or more embodiments of the present disclosure, and the devices may interact with each other to complete the method.

It should be noted that the above description describes certain embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims may be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing may also be possible or may be advantageous.

As shown in fig. 10, the present specification further provides a circuit breaker failure fault detection apparatus for a pumped storage generator motor, including:

the state judgment module is used for detecting whether the system is in a loaded state or a light-load state through memory current criteria when the breaker failure protection is started; the memory current is the current before the pumped storage generator motor fails;

the load detection module is used for detecting whether a breaker failure fault occurs and judging a fault phase according to a phase current criterion, a negative sequence current criterion and a fundamental wave voltage phase difference criterion in a load state;

the light load detection module is used for detecting whether a breaker failure fault occurs or not according to the phase current criterion, the negative sequence current criterion and the third harmonic voltage phase difference criterion in a light load state;

for convenience of description, the above devices are described as being divided into various modules by functions, and are described separately. Of course, the functionality of the modules may be implemented in the same one or more software and/or hardware implementations in implementing one or more embodiments of the present description.

The apparatus of the foregoing embodiment is used to implement the corresponding method in the foregoing embodiment, and has the beneficial effects of the corresponding method embodiment, which are not described herein again.

Fig. 11 is a schematic diagram illustrating a more specific hardware structure of an electronic device according to this embodiment, where the electronic device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein the processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 are communicatively coupled to each other within the device via bus 1050.

The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an Application Specific Integrated Circuit (ASIC), or one or more Integrated circuits, and is configured to execute related programs to implement the technical solutions provided in the embodiments of the present disclosure.

The Memory 1020 may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, or the like. The memory 1020 may store an operating system and other application programs, and when the technical solution provided by the embodiments of the present specification is implemented by software or firmware, the relevant program codes are stored in the memory 1020 and called to be executed by the processor 1010.

The input/output interface 1030 is used for connecting an input/output module to input and output information. The i/o module may be configured as a component in a device (not shown) or may be external to the device to provide a corresponding function. The input devices may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output devices may include a display, a speaker, a vibrator, an indicator light, etc.

The communication interface 1040 is used for connecting a communication module (not shown in the drawings) to implement communication interaction between the present apparatus and other apparatuses. The communication module can realize communication in a wired mode (such as USB, network cable and the like) and also can realize communication in a wireless mode (such as mobile network, WIFI, Bluetooth and the like).

Bus 1050 includes a path that transfers information between various components of the device, such as processor 1010, memory 1020, input/output interface 1030, and communication interface 1040.

It should be noted that although the above-mentioned device only shows the processor 1010, the memory 1020, the input/output interface 1030, the communication interface 1040 and the bus 1050, in a specific implementation, the device may also include other components necessary for normal operation. In addition, those skilled in the art will appreciate that the above-described apparatus may also include only those components necessary to implement the embodiments of the present description, and not necessarily all of the components shown in the figures.

The electronic device of the foregoing embodiment is used to implement the corresponding method in the foregoing embodiment, and has the beneficial effects of the corresponding method embodiment, which are not described herein again.

Computer-readable media of the present embodiments, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the spirit of the present disclosure, features from the above embodiments or from different embodiments may also be combined, steps may be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present description as described above, which are not provided in detail for the sake of brevity.

In addition, well-known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown in the provided figures, for simplicity of illustration and discussion, and so as not to obscure one or more embodiments of the disclosure. Furthermore, devices may be shown in block diagram form in order to avoid obscuring the understanding of one or more embodiments of the present description, and this also takes into account the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform within which the one or more embodiments of the present description are to be implemented (i.e., specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that one or more embodiments of the disclosure can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative instead of restrictive.

While the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art in light of the foregoing description. For example, other memory architectures (e.g., dynamic ram (dram)) may use the discussed embodiments.

It is intended that the one or more embodiments of the present specification embrace all such alternatives, modifications and variations as fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions, improvements, and the like that may be made without departing from the spirit and principles of one or more embodiments of the present disclosure are intended to be included within the scope of the present disclosure.