阅读说明：本技术 一种提高小水电上网线路重合闸成功率的方法 (method for improving reclosing success rate of small hydropower station internet line ) 是由 吴英山 陈朝新 卞超 陆华晴 陈镜巨 王勇 钟建业 邓寒 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种提高小水电上网线路重合闸成功率的方法,包括根据预设策略确定10KV电网侧的出线开关是否发生跳闸；当确定10KV电网侧的出线开关发生跳闸时,对所述并网开关进行分闸处理,以停止水电并网外送；当延时时间大于所述出线开关的自动重合闸时间时,对所述并网开关进行合闸处理,以恢复水电并网外送。本发明提供的一种提高小水电上网线路重合闸成功率的方法,能够有效解决分布式电源接入,特别是多个小水电非专线接入配电网对线路重合闸造成成功率低下的问题。(the invention discloses a method for improving the reclosing success rate of a small hydropower station network line, which comprises the steps of determining whether an outgoing switch at the 10KV power grid side trips or not according to a preset strategy; when the outlet switch at the 10KV power grid side is determined to be tripped, the grid-connected switch is subjected to brake separating processing to stop water and electricity grid-connected delivery; and when the delay time is longer than the automatic reclosing time of the outgoing line switch, closing the grid-connected switch to recover the water and electricity grid-connected delivery. The method for improving the reclosing success rate of the small hydropower station internet line can effectively solve the problem of low success rate of circuit reclosing caused by the fact that a plurality of small hydropower stations are connected to a power distribution network in an non-exclusive mode.)

1. the method for improving the reclosing success rate of the small hydropower station internet line is characterized by being realized by a system for improving the reclosing success rate of the small hydropower station internet line, wherein the system comprises an in-situ protection measurement and control device arranged on a power supply side of the small hydropower station, an outgoing line switch monitoring device arranged on a 10KV power supply side and a main station which is respectively in communication connection with the in-situ protection measurement and control device and the outgoing line switch monitoring device, and the method comprises the following steps:

determining whether an outgoing line switch on the 10KV power grid side trips or not according to a preset strategy;

When the outlet switch at the 10KV power grid side is determined to be tripped, the grid-connected switch is subjected to brake separating processing to stop water and electricity grid-connected delivery;

when the delay time is longer than the automatic reclosing time of the outgoing line switch, closing the grid-connected switch to recover water and electricity grid-connected delivery;

The automatic reclosing time refers to the time for reclosing automatically after the outgoing switch trips.

2. The method for improving the reclosing success rate of the small hydropower station network line according to claim 1, wherein the step of determining whether the outgoing switch at the 10KV power grid side trips or not according to a preset strategy comprises the following steps:

the voltage and the frequency of the small hydropower station power supply side are collected in real time through the in-situ protection measurement and control device, and whether the outgoing line switch of the 10KV power grid side is displaced or not is monitored in real time through the outgoing line switch monitoring device;

when the acquired voltage and/or frequency exceed the forced disconnection limit value and the monitored outgoing switch is displaced, the in-situ protection measurement and control device determines that the outgoing switch on the 10KV power grid side trips;

when the collected voltage and/or frequency do not exceed the forced disconnection limit value but the monitored outgoing switch is displaced, the outgoing switch monitoring device determines that the outgoing switch on the 10KV power grid side trips;

and when the acquired voltage and/or frequency do not exceed the forced disconnection limit value and the monitored outgoing switch does not shift, the in-situ protection measurement and control device and the outgoing switch monitoring device determine that the outgoing switch on the 10KV power grid side does not trip.

3. the method for improving the reclosing success rate of the small hydropower station network line according to claim 2, wherein the step of performing switching-off processing on the grid-connected switch to stop hydropower grid-connected outgoing when the outgoing switch at the 10KV power grid side is determined to be tripped comprises the following steps of:

When the in-situ protection measurement and control device determines that the outgoing switch at the 10KV power grid side trips, the in-situ protection measurement and control device outputs a brake-separating control signal to the grid-connected switch at the small hydropower station power supply side;

and the grid-connected switch executes the opening operation according to the opening control signal so as to stop the water and electricity grid-connected delivery.

4. The method for improving the reclosing success rate of the small hydropower station network line according to claim 3, wherein the step of carrying out switching-on treatment on the grid-connected switch to recover the hydropower grid-connected delivery when the delay time is longer than the automatic reclosing time of the outlet switch comprises the following steps:

When the delay time is longer than the automatic reclosing time of the outlet switch, the in-situ protection measurement and control device outputs a closing control signal to a grid-connected switch at the power supply side of the small hydropower station;

and the grid-connected switch executes a closing operation according to the closing control signal so as to recover the water and electricity grid-connected delivery.

5. the method for improving the reclosing success rate of the small hydropower station network line according to claim 2, wherein the step of performing switching-off processing on the grid-connected switch to stop hydropower grid-connected outgoing when the outgoing switch at the 10KV power grid side is determined to be tripped comprises the following steps of:

when the outgoing line switch monitoring device determines that an outgoing line switch at the 10KV power grid side trips, the outgoing line switch monitoring device sends a tripping event to a main station;

After receiving the tripping event, the master station issues a switching-off control command to the in-situ protection measurement and control device;

After receiving the opening control command, the in-situ protection measurement and control device outputs an opening control signal to a grid-connected switch at the power supply side of the small hydropower station;

and the grid-connected switch executes the opening operation according to the opening control signal so as to stop the water and electricity grid-connected delivery.

6. the method for improving the reclosing success rate of the small hydropower station network line according to claim 5, wherein the step of carrying out switching-on treatment on the grid-connected switch to recover the hydropower grid-connected outgoing transmission when the delay time is longer than the automatic reclosing time of the outgoing switch comprises the following steps:

When the delay time is longer than the automatic reclosing time of the outgoing line switch, the master station issues a closing control command to the on-site protection measurement and control device;

after receiving the switching-on control command, the in-situ protection measurement and control device outputs a switching-on control signal to a grid-connected switch at the power supply side of the small hydropower station;

and the grid-connected switch executes a closing operation according to the closing control signal so as to recover the water and electricity grid-connected delivery.

Technical Field

the invention relates to the technical field of power systems, in particular to a method for improving the reclosing success rate of a small hydropower station internet line.

background

The reclosing device is widely applied to power line protection and is one of self-recovery power supply methods commonly adopted in power grid operation. Reclosing is a method of closing a circuit breaker in a short time after an overhead line fault is cleared. The line faults of the power grid are divided into permanent faults and instantaneous faults, after the circuit breaker trips, fault points still exist, and can be eliminated after repair processing, such as pole collapse, line breakage, electric equipment burnout and the like; and the instantaneous fault means that after the fault, the breaker is tripped open, and after a period of time, the fault disappears, such as lightning and pollution flashover cause the surface flashover discharge of the insulator, the discharge caused by strong wind, and the like, and the part of the fault accounts for 60-90% of the total fault. Reclosing is widely used precisely because in practice most overhead line faults are instantaneous or temporary.

reclosing is divided into two modes of protection starting and non-corresponding starting reclosing. For the distribution network, the switch is usually a three-phase integrated structure, so that the protection starting is the most common mode for the distribution network. The realization mode of the on-site protection device is mainly realized by the on-site protection device through self functional logic, namely, a protection starting reclosing mode, such as overcurrent protection starting reclosing, zero sequence protection starting reclosing and the like.

with the improvement of the requirement on the reliability of electric power, distributed power supplies such as small hydropower stations and the like are widely connected, the influence on a power distribution network is more and more obvious, and particularly, the reclosing function cannot well meet the requirement. For example, small hydropower resources in Guangdong Yuebei areas are abundant, and small hydropower stations are numerous and have the following characteristics: (1) the single machine has small capacity, and most of the single machine can be connected with the Internet through a line with a voltage level of 10 kV; (2) the network access line is not a special line basically, but the small hydropower stations access the network and the public transformer area are shared; (3) dispersing station sites; (4) the section mountain through which the network access line passes is high in forest density and is also in a thunder active area, and the tripping of the line caused by instantaneous grounding or lightning stroke is more than that of the conventional line. The small hydropower station is small, the fault resistance is low, the small hydropower station is not cut off during reclosing, instant impact is possibly generated, the unit is damaged, unnecessary loss and civil dispute are generated, the small hydropower station unit influencing reclosing needs to be cut off, and the success rate of reclosing is improved.

disclosure of Invention

the invention provides a method for improving the reclosing success rate of a small hydropower station internet line, and aims to overcome the defects in the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

a method for improving the reclosing success rate of a small hydropower station internet line is realized by a system for improving the reclosing success rate of the small hydropower station internet line, the system comprises an in-situ protection measurement and control device arranged on the power supply side of the small hydropower station, an outgoing line switch monitoring device arranged on the 10KV power supply side and a main station which is respectively in communication connection with the in-situ protection measurement and control device and the outgoing line switch monitoring device, and the method comprises the following steps:

Determining whether an outgoing line switch on the 10KV power grid side trips or not according to a preset strategy;

when the outlet switch at the 10KV power grid side is determined to be tripped, the grid-connected switch is subjected to brake separating processing to stop water and electricity grid-connected delivery;

when the delay time is longer than the automatic reclosing time of the outgoing line switch, closing the grid-connected switch to recover water and electricity grid-connected delivery;

the automatic reclosing time refers to the time for reclosing automatically after the outgoing switch trips.

Further, in the method for improving the reclosing success rate of the small hydropower station network line, the step of determining whether the outgoing switch at the 10KV power grid side trips according to a preset strategy includes:

The voltage and the frequency of the small hydropower station power supply side are collected in real time through the in-situ protection measurement and control device, and whether the outgoing line switch of the 10KV power grid side is displaced or not is monitored in real time through the outgoing line switch monitoring device;

when the acquired voltage and/or frequency exceed the forced disconnection limit value and the monitored outgoing switch is displaced, the in-situ protection measurement and control device determines that the outgoing switch on the 10KV power grid side trips;

when the collected voltage and/or frequency do not exceed the forced disconnection limit value but the monitored outgoing switch is displaced, the outgoing switch monitoring device determines that the outgoing switch on the 10KV power grid side trips;

and when the acquired voltage and/or frequency do not exceed the forced disconnection limit value and the monitored outgoing switch does not shift, the in-situ protection measurement and control device and the outgoing switch monitoring device determine that the outgoing switch on the 10KV power grid side does not trip.

Further, in the method for improving the reclosing success rate of the small hydropower station network line, when it is determined that the outgoing switch at the 10KV power grid side trips, the step of performing switching-off processing on the grid-connected switch to stop the hydropower grid-connected outgoing includes:

when the in-situ protection measurement and control device determines that the outgoing switch at the 10KV power grid side trips, the in-situ protection measurement and control device outputs a brake-separating control signal to the grid-connected switch at the small hydropower station power supply side;

And the grid-connected switch executes the opening operation according to the opening control signal so as to stop the water and electricity grid-connected delivery.

Further, in the method for improving the reclosing success rate of the small hydropower station network line, when the delay time is longer than the automatic reclosing time of the outgoing line switch, the step of carrying out closing processing on the grid-connected switch to recover hydropower grid-connected outgoing comprises the following steps:

when the delay time is longer than the automatic reclosing time of the outlet switch, the in-situ protection measurement and control device outputs a closing control signal to a grid-connected switch at the power supply side of the small hydropower station;

And the grid-connected switch executes a closing operation according to the closing control signal so as to recover the water and electricity grid-connected delivery.

Further, in the method for improving the reclosing success rate of the small hydropower station network line, when it is determined that the outgoing switch at the 10KV power grid side trips, the step of performing switching-off processing on the grid-connected switch to stop the hydropower grid-connected outgoing includes:

when the outgoing line switch monitoring device determines that an outgoing line switch at the 10KV power grid side trips, the outgoing line switch monitoring device sends a tripping event to a main station;

after receiving the tripping event, the master station issues a switching-off control command to the in-situ protection measurement and control device;

after receiving the opening control command, the in-situ protection measurement and control device outputs an opening control signal to a grid-connected switch at the power supply side of the small hydropower station;

And the grid-connected switch executes the opening operation according to the opening control signal so as to stop the water and electricity grid-connected delivery.

Further, in the method for improving the reclosing success rate of the small hydropower station network line, when the delay time is longer than the automatic reclosing time of the outgoing line switch, the step of carrying out closing processing on the grid-connected switch to recover hydropower grid-connected outgoing comprises the following steps:

when the delay time is longer than the automatic reclosing time of the outgoing line switch, the master station issues a closing control command to the on-site protection measurement and control device;

after receiving the switching-on control command, the in-situ protection measurement and control device outputs a switching-on control signal to a grid-connected switch at the power supply side of the small hydropower station;

and the grid-connected switch executes a closing operation according to the closing control signal so as to recover the water and electricity grid-connected delivery.

The method for improving the reclosing success rate of the small hydropower station network line can effectively solve the problem of low success rate of circuit reclosing caused by access of a distributed power supply, particularly access of a plurality of small hydropower stations to a power distribution network in an non-exclusive mode.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a method for improving the reclosing success rate of a small hydropower station network line according to a first embodiment of the invention;

fig. 2 is a method for improving the reclosing success rate of a small hydropower station network line according to the second embodiment of the invention;

fig. 3 is a method for improving the reclosing success rate of a small hydropower station network line provided by the third embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.