Distribution network generally refers to a power network with a voltage level of 35kV and below, and its role is to supply power to various distribution stations and various types of electricity loads in the city. At present, most of the urban distribution lines in China use a voltage level of 10kV to supply electricity to users. The distribution line has a wide distribution area and a long total length, but the operating environment is harsh, and it is very easy to break the line due to lightning strikes, mechanical external forces and line load overload, which seriously threatens the safety and reliability of power supply. After the line breaks the fault, the voltage quality of the system will be greatly affected, the three-relative symmetry of the system will be destroyed, and it may also cause the motor to burn out due to the lack of phase operation, which greatly reduces the service life of the equipment. In addition, after the disconnection, there is a great possibility that various grounding failures will continue to occur, which may cause fires and even electrocute people and animals, resulting in consequences that are difficult to save.
[0003] The prior art by analyzing the distribution network when a single-phase disconnected line fault occurs negative sequence current distribution law in the system, it is obtained that most of the negative sequence current of the system after the fault point flows to the power supply through the fault line, rather than the negative sequence current of the fault line is relatively small, as a theoretical basis for fault line selection, and the maximum and smallest difference after the absolute value of the fault phase current difference in the three-phase processing result is the largest, the fault phase can be preliminarily determined, and then take half of the negative sequence current within the cycle and the fault phase voltage The product of the integral value of time is used as an energy measure, and the action criterion is: it is tuned according to the maximum energy measure that avoids the failure of the single-phase disconnection of other feeders.
[0004] The prior art for 10kV overhead line radial topology characteristics, the use of fault component method of the single-phase disconnected fault negative sequence voltage distribution analysis, the proposed based on the negative sequence voltage amplitude of the single-phase breakage criterion. Combined with the analysis of the minimum path from the load monitoring point to the power point, the single-phase disconnection fault area determination method based on the load monitor is proposed, and the possible and impossible areas of the single-phase disconnection fault are delineated, and the two areas are used as a differential set operation to obtain the minimum disconnection fault area.
[0005] 上述技术中的故障分析故障分析故障检测定位方案有如下缺点: [0005] The above-mentioned techniques in the fault analysis and fault detection location scheme have the following disadvantages:
[0006] (1)上述文件通常相断線故障提出处理方法,对附加地故障,特別对多相断線故障缺少充分分析,Solution relatively single,且難理解故障故障; [0006] (1) The above documents are all for the processing method proposed by the single-phase fault failure, the additional ground fault, in particular, the lack of adequate analysis of the multi-phase fault fault, the solution is relatively single, and it is difficult to judge the type of fault;
[0007] (2)通过检测负序电流电压作为判定依据,需要负载侧增加设备,增加投資和设备操作維的 WORKLOAD; [0007] (2) by detecting negative sequence current voltage as a judgment basis, the need to increase the workload of investment and equipment operation and maintenance;
(3) by comparing voltage current phase difference as a judgment basis, in the special load type case is easy to cause misjudgment, reliability is difficult to guarantee;
[0009] (4) by dividing the area to determine the fault location is still difficult to accurately determine the fault segment, the need to assist manual inspection to determine the specific fault point.
Problem splitting
Including: obtaining the voltage and current information of each node of the distribution network; determining the faulty line according to the collected distribution network current information, and judging whether the faulty line is a disconnected line fault; determining whether it is a single-phase or multi-phase disconnected fault; determining the specific fault type of single-phase or multi-phase disconnected line fault; and determining whether the voltage information of each node is consistent by comparing the voltage information of each node forward or backward to determine the specific fault section. Beneficial effects of the present invention: by collecting the voltage and current information, not only can the determination of single-phase disconnection and its grounding complex fault, but also can accurately detect and locate the multiphase disconnection and its grounding complex fault, shortening the time of fault processing.
Problem solving
This paper proposes a 10kV distribution line break fault determination method based on three-phase voltage current, which only relies on the information available on the existing equipment, without adding new equipment; the judgment principle is simple and the reliability is high; and the single-phase and multi-phase disconnection lines and their grounding complex faults can be accurately determined.
[0011] 为实现上述目的,本发明采用以下述技术方案: [0011] To achieve the above object, the present invention employs the following technical scheme:
[0012] 基于三相电压电流的10kV distribution line断 fault determination method, 包括: [0012] 10kV distribution line fault determination method based on three-phase voltage current, comprising:
(1) obtain the voltage, current information of each node of the distribution grid; if a measurement point or a few measurement points of the voltage current change amplitude exceeds the set threshold, then the distribution line fault;
(2) according to the collection of distribution network current information to determine the fault of the line, and judge the fault line is not a broken line fault, if it is, into the next step, otherwise, end;
[0015] (3)判断故障型為單相断線故障或多相断線故障;如果是單相断線故障,入步骤(4);如果是多相断線故障,入步骤(5); [0015] (3) To judge the type of failure is a single-phase broken line fault or a multi-phase broken line fault;
(4) according to the fault before the phase voltage effective value, fault after the power supply side of the bus line each phase voltage effective value and voltage tuning value relationship, determine the single phase broken line fault of the specific fault type; into the step (6);
(5) according to the fault before the phase voltage effective value, fault after the power supply side bus each phase voltage effective value, fault after the load side relative ground voltage and voltage tuning value relationship, determine the specific fault type of multi-phase broken line fault; enter the step (6);
[0018] (6) By comparing the voltage information of each node forward or backward is consistent, the specific fault segment is determined.
[0019] 进一地,所述步骤(2)中,如果配网线路三相电流中出一相电流失或三相电流全降低,則该配网线路确定為故障线路; [0019] Further step, the step (2) in, if the distribution network line three-phase current appears in a phase current missing or three-phase current all reduced, then the distribution network line is determined to be a fault line;
[0020] When the absolute value of at least one phase current appears on the fault line is less than the current tuning threshold value, the fault line is determined to be a broken fault.
[0021] 进一地,所述步骤(3)中, [0021] Further, the steps (3) in,
[0022] 如果同時satisfied以下条件,則判断為單相断線故障: [0022] If the following conditions are met at the same time, the judgment is a single-phase broken line fault:
[0023] 1)其中一相的电流有效值的絕值不大电流定门槛值; [0023] 1) wherein the absolute value of the current effective value of the current is not greater than the current tuning threshold value;
[0024] 2)另外兩相的电流有效值的絕值相,以及其值之間,IN為障前相电流有效值; [0024] 2) an absolute value of the current effective value of the other two phases, and its value is between, IN is therefore barrier front phase current effective value;
[0025] 3)另外兩相的电流相位角的差值之間[120°,180°]之間; [0025] between [0025] the current phase angle of the other two phases between [120 °,180 °];
[0026] If the effective value of the fault line three-phase current is equal, and the absolute value is not greater than the current tuning threshold value, it is determined that a multiphase disconnected fault occurs.
[0027] 进一地,所述步骤(4)中,單相断線故障具体故障型判定方法为: [0027] Further step, the step (4) in, the judgment method of the specific fault type of the single-phase broken line fault is:
[0028] 1)判断是否出电压为零的相,則決定為單相断線兩端悬故障,电压上的一相判為断線故障相;如果有,則附有地故障,轉下步; [0028] 1) to determine whether the voltage is zero phase, if not, then the judgment is a single phase broken line two ends of the suspension fault, the voltage rise of a phase of the broken line fault; if there is, then accompanied by a ground fault, turn into the next step;
[0029] 2) Determine the power supply is zero phase on the power side or on the load side, if on the power side, then determined to be a single-phase broken line plus power side ground fault, the voltage of zero phase is determined to be a broken line fault phase; if on the load side, then determined to be a single-phase broken line plus load side ground fault, the phase with a voltage of zero is determined to be a broken line fault phase.
[0030] Further, in step (5), the specific fault type of the multiphase disconnection fault comprises: two-phase disconnection fault, two-phase disconnection plus power side one-phase grounding fault, two-phase disconnection plus load side one-phase grounding fault, three-phase disconnected fault.
[0031] 进一地,所述步骤(5)中, [0031] Further, the steps (5) in,
[0032] 如果故障线路三相电流满足小于电流整定门槛值,且出一相电压降0,則判断是否為负载侧电压降0: [0032] 如果故障线路三相电流满足满足小于电流定隔隔隔电压降0: [0032] 如果故障线路三相电流满足小于电流整定 threshold value, and the emergence of a phase voltage down to 0, then determine whether the load side voltage drops to 0:
[0033] 如果负载侧电压降0,則可決定為發生兩相断線加负载侧一相接地故障,電侧电压非0兩相為故障相; [0033] 如果负载侧电压降0,則可可決定为故障相; [0033] 如果负载侧电压降0,則可決定為發生兩相断加负载侧一相接地故障, power supply side电压非02相為故障相; [0033] If the load side voltage drops to 0, then it can be judg
[0034] If the load side voltage is not 0, it is determined that a two-phase disconnection plus a power side ground fault occurs, the power side voltage and the load side voltage are different from the two phases are fault phases.
[0035] 进一地,所述步骤(5)中, [0035] Further, the steps (5) in,
[0036] If the fault line three-phase current is satisfied less than the current setting threshold value, and no one-phase voltage is 0; then determine whether the power supply side phase voltage changes, if there is a change, then it is determined that the two-phase disconnection is not grounded fault, the two voltage rise phase is a disconnected fault phase.
[0037] 进一地,所述步骤(5)中, [0037] Further step, 所述步骤(5)中, [0037] Further step, 所述步骤(5)中, [0037]
[0038] If the load side of the various phase voltages down to 0, the power side voltage remains unchanged, then the judgment is a three-phase disconnect fault.
[0039] 进一地,确定具体故障段的方法為: [0039] Further ground, the method of determining the specific fault segment is:
[0040] 如果電侧电压曲线超過設阈值,則從電侧节点開始向後尋事件一一节点电压和二個节点电压,如果兩者致,再比较電邊节点後第二個节点电压和三個节点电压,直到找到节点电压信息不一致兩個节点,則決定障點位置在這兩個节点之間; [0040] If the power side voltage changes beyond the set threshold, then from the power side node start to look for the fault point backwards, first compare the first node voltage and the second node voltage after the power side node, if the two are consistent, then compare the second node voltage and the third node voltage after the power side node, until the node voltage information is not consistent with the two nodes, then determine the barrier point is located between these two nodes;
[0041] If the power supply side bus voltage change does not exceed the set threshold, the fault after the load side voltage change will exceed the set threshold, at this time from the load side to start looking forward for the fault point, find the adjacent node voltage information is inconsistent with the two nodes, then determine the fault point is located between the two nodes.
[0042] 本发明的有益效果是: [0042] The beneficial effects of the present invention are:
1. The principle of the present invention is simple, to achieve easy; no need to additional increase equipment, low cost, do not increase the operation and maintenance workload;
[0044] 2. By the collected voltage and current information, not only can the determination of single-phase disconnection and its grounding complex fault, but also can accurately detect and locate the multiphase disconnection and its grounding complex fault, shorten the fault processing time.