Grounding protection method and system for serially connecting resistor injection type stator from arc suppression coil
A technology of stator grounding protection and arc suppression coil, which is applied in the direction of emergency protection circuit devices, emergency protection circuit devices, electrical components, etc. for limiting overcurrent/overvoltage, and can solve the problem of unsatisfactory protection application effects, small inductive reactance, Solve problems such as small inductance value of arc suppressing coil, achieve the effect of improving signal measurement conditions, increasing size, and being easy to implement
Active Publication Date: 2021-01-15
TIANSHENGQIAO TWO HYDROPOWER CO LTD +1
View PDF12 Cites 2 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
In order to compensate the capacitive current, the inductance value of the arc suppressing coil is small, resulting in a small inductive reactance at 20Hz, resulting in a small 20Hz signal injected from the power supply unit to the neutral point of the generator when the injection stator grounding protection is applied. The measurement of the signal brings difficulties, which ultimately leads to unsatisfactory protection application effect
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
[0033]This embodiment will be clearly described below in conjunction with the drawings.
[0034]In this embodiment, a resistance injection type stator grounding protection method is connected from the arc suppression coil in series, without changing the grounding method of the neutral point of the large hydro-generator (to reduce the difficulty of motor design and manufacturing) The arc coil 1 is connected in series with a resistor 3 (used to suppress the transmission of overvoltage) to realize the injection of the 20Hz signal of the injection stator grounding protection. This method specifically includes the following steps:
[0035]Step 1: Inject a 20Hz voltage signal from both ends of the arc suppression coil 1 on the neutral point side of the generator connected to the resistor 3; the resistor divider of the stator grounding protection device 4 is connected to both ends of the resistor 3, and is detected by the resistor divider Injected voltage signal (seeimage 3 ); Wound the intermed...
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 grounding protection method and system for serially connecting a resistor injection type stator from an arc suppression coil. The method comprises the steps that 20 Hz voltagesignals are injected from the two ends of an arc suppression coil series resistor on the neutral point side of a generator; a stator grounding protection device performs impedance compensation calculation by using the measured 20Hz voltage and 20Hz current to obtain 20Hz voltage and 20Hz current actually injected into two ends of a generator stator winding grounding branch, calculates grounding admittance, takes the reciprocal of the real part of the grounding admittance, and multiplies the reciprocal by a resistance conversion coefficient to obtain a grounding fault transition resistance value; and the calculated grounding fault transition resistance value is used as a protection criterion, when the calculated grounding fault transition resistance value is lower than a high-section constant value, an alarm action is executed, and when the calculated grounding fault transition resistance value is lower than a low-section constant value, a tripping action is executed. According to the invention, the neutral point grounding mode of the generator is not changed, and the grounding fault transition resistance value can be accurately calculated.
Description
Technical field[0001]The invention belongs to the technical field of the design and manufacture of large hydroelectric generators and the relay protection of the main equipment of the power system, and in particular relates to a stator grounding protection method and system of a resistance injection type from an arc suppression coil in series.Background technique[0002]Stator single-phase grounding fault is the most common fault of large generator stator winding insulation damage. The main hazard to the generator is the burn of the stator core and the expansion of the ground fault to inter-phase or inter-turn short circuit. Therefore, the generator protects the A screen / B screen It has become a trend to configure different principles of stator ground protection (dual frequency and injection).[0003]The injection stator grounding protection has been widely used in the way that the neutral point of the generator is grounded with high resistance through the power distribution (seefigure ...
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 Applications(China)
IPC IPC(8): H02H7/06H02H9/08
CPCH02H7/06H02H9/08
Inventor 钟波李刚周万竣周红斌叶锐黄凯徐子林王园园
Owner TIANSHENGQIAO TWO HYDROPOWER CO LTD