A method, system and unlocking method for fault blocking outside the current differential protection zone
A differential protection zone and differential protection technology, applied in the direction of automatic disconnection emergency protection devices, emergency protection circuit devices, electrical components, etc., can solve problems such as false braking, large amount of calculation, and poor real-time performance, and achieve Prevent misoperation of current differential protection, accurate discrimination, and simple principle
Active Publication Date: 2019-06-21
济南鲁源电气集团有限公司 +3
View PDF5 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0004] 2) Harmonic braking method to identify CT saturation through the second harmonic and third harmonic, this method has the defect of false braking when there is a fault in the area;
[0005] 3) The wavelet method for identifying the singularity characteristics of CT saturation signals has the disadvantages of large amount of calculation, poor real-time performance, and boundary effects that are difficult to clearly define
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0035] It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0036] It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and / or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and / or combinations thereof.
[0037] figure 1 It is a flow chart of a method for blocking faults outside the current differential protection ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a current differential protection external fault locking method, system and unlocking method. The current differential protection external fault locking method comprises the steps of obtaining voltage and current synchronous sampling data in all side circuit breakers in differential protection according to differential protection requirements, and then calculating a sampling power fault component of each side circuit breaker in real time; if the sampling power fault component of a certain side circuit breaker is a positive value, selecting circuit breaker correspondingsides with positive value and negative value of the sampling power fault components and the maximum absolute values separately; and if the absolute values of the positive value and the negative valueof the screened current fault components are used as a current differential action quantity and a current differential brake quantity respectively, the current differential action conditions are satisfied, and the accumulative number of times of satisfying the conditions in a time frame of a preset half sampling period or less is kept to be equal to one to half of the number of sampling points ofeach sampling period, proving that the current fault is the external fault, and performing a locking current differential protection action.
Description
technical field [0001] The invention relates to a differential protection method, in particular to a method, system and unlocking method for fault blocking outside the current differential protection zone. Background technique [0002] Differential protection is a protection principle widely used in power systems due to its simple principle, sensitive response, and wide application range. However, when an external fault occurs and CT saturation occurs, differential protection is very prone to misoperation due to external faults. Condition. At present, the methods and defects of preventing differential protection misoperation caused by CT saturation mainly include: [0003] 1) Based on the time difference method that CT saturation will not occur immediately when an external fault occurs, this method must go through a certain delay before opening the action when the external fault is transferred to the internal fault, which has a certain impact on the rapid action of the prot...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H02H3/28H02H7/04
CPCH02H3/283H02H7/042
Inventor 李丽红贾慧芝吕秀英刘净孙凤燕孙方伟
Owner 济南鲁源电气集团有限公司