CN201319283Y

CN201319283Y - Novel generator rotor demagnetization and over-voltage protecting device

Info

Publication number: CN201319283Y
Application number: CNU2008201865282U
Authority: CN
Inventors: 黄冬华; 李开明; 刘守茹; 刘贵仁; 李振
Original assignee: Hefei Kaili Control Technology LLC; Baishan Power Plant
Current assignee: Hefei Kaili Control Technology LLC; Songhua River Hydropower Generation Co Ltd Jilin Baishan Power Plant; State Grid Xinyuan Hydropower Co Ltd; State Grid Corp of China SGCC
Priority date: 2008-10-24
Filing date: 2008-10-24
Publication date: 2009-09-30
Anticipated expiration: 2018-10-24

Abstract

The utility model relates to a novel generator rotor demagnetization and overvoltage protection device, which belongs to the technical field of electric power equipment. Its purpose is to provide a new type of generator rotor demagnetization and overvoltage protection device which not only has good voltage limiting effect, but also has good current equalization, is easy to assemble, and occupies a small space. Its technical points are: it is composed of zinc oxide non-linear resistance valve plate, silicon carbide non-linear resistance valve plate and bracket. Zinc oxide non-linear resistance valves and silicon carbide non-linear resistance valves are connected in series to form a valve group, and each valve group is equipped with two upper and lower electrode taps, which can be combined in series and parallel according to different voltage levels and energy capacities to be installed on the bracket superior. It not only has good voltage limiting effect, but also has good current equalization, simple assembly process, convenient installation, wide protection range, and small space occupation; when used, it can be combined flexibly and arbitrarily according to different voltage levels and energy capacities of protection.

Description

New-generation machine rotor demagnetization and overvoltage protection

Technical field

The utility model relates to a kind of new-generation machine rotor demagnetization and overvoltage protection, belongs to electrical equipment technical field.

Background technology

Many weeks, synchronous generator rotor to the requirement of demagnetization and rotor over-voltage protection be cut-off reliably, demagnetization is rapid, the pressure limiting characteristic is good, field suppression equipment is reliable, easy maintenance.So far, the method that is used for demagnetization mainly contains: linear resistance demagnetization, arc-chute demagnetization, field suppression switch demagnetization, inversion field suppression, nonlinear resistance demagnetization etc.Wherein use maximum be adopt field circuit breaker to cooperate znr to move can demagnetization.Znr is a kind of varistor; be used for the history in existing more than 30 year of protecting electrical power system; it is smooth that it has voltage-current characteristic; pressure limiting is effective, protects series of advantages such as effective, inexpensive; therefore; in the generator amature overvoltage protection, remanent magnetism absorbs, and in the lightning arrester irreplaceable protective effect is arranged.But, because the knee voltage height of znr, the current-sharing difficulty, therefore, during as generator amature demagnetization and overvoltage protection,, often need to install additional special fuse in order to guarantee the current sharing of ZnO resistors, so just caused that to take the cabinet volume big, laid problems such as difficulty; Simultaneously, the assembling of znr is more complicated also, and occupation space is bigger.

Summary of the invention

The purpose of this utility model is to provide a kind of not only pressure limiting effective, and current sharing good, be easy to new-generation machine rotor demagnetization and the overvoltage protection that assembles, takes up room little.

Its technical scheme is: a kind of new-generation machine rotor demagnetization and overvoltage protection; form by znr valve block, silicon carbide nonlinear resistor valve block and support; it is characterized in that: constitute the valve block group by znr valve block and the series connection of silicon carbide nonlinear resistor valve block; each valve block group is provided with upper and lower two electrode taps, and the valve block group is rack-mount successively.

Its technique effect is: the utility model is owing to made full use of the silicon carbide nonlinear resistor nonlinear characteristic; characteristics such as the good and znr pressure limiting of current sharing is effective; silicon carbide nonlinear resistor connected with znr constitutes a kind of novel demagnetization over-pressure safety device, thus solved simple employing znr as the existing current-sharing difficulty of demagnetization over-pressure safety device, need install special fuse additional and take up room problem such as big.Not only pressure limiting is effective for it, and current sharing is good, simple for assembly process, easy for installation, and protection range is wide, and it is little to take up room; During use, can be according to the different electric pressures of protection and can capacity, flexibly, at random made up.

Description of drawings

Fig. 1 is the utility model structural representation;

Fig. 2 is that the A of Fig. 1 is to view;

Fig. 3 is the volt-ampere characteristics of figure of znr and silicon carbide nonlinear resistor.

Embodiment

As shown in Figure 1, 2, new-generation machine rotor demagnetization and overvoltage protection are made up of znr (ZNO) valve block, silicon carbide nonlinear resistor (SiC) valve block and support.

Znr valve block

2 and 1 series connection of a slice silicon carbide nonlinear resistor valve block by two, three or multi-disc constitute the valve block group, the silicon carbide nonlinear resistor valve block places an end of valve block group, and the znr valve block places the other end of valve block group.Each valve block group is provided with upper and lower two electrode taps 3, and the valve block group is fixed on the support 4 successively.

Its operation principle (see figure 3):, realize change of current demagnetization under zero load or rated condition when generator during little electric current demagnetization, because carborundum resistance has the low characteristic of conducting voltage, thereby can guarantee to start demagnetization and overvoltage protection under low-voltage state.

When generator in short circuit or when encouraging under the accident conditions demagnetization by force because carborundum resistance has current sharing, thereby can be distributed to energy even on each ZnO resistors, reach quick consumption magnetic field energy.

When a certain valve block group in the device occurred aging or damages fault, the carborundum resistance in this valve block group is open circuit automatically, and fault valve block group is deactivated automatically, guaranteed that demagnetization is reliable.

Claims

1. The new generator rotor demagnetization and overvoltage protection device is composed of a zinc oxide non-linear resistance valve plate, a silicon carbide non-linear resistance valve plate and a bracket, and is characterized in that: it consists of a zinc oxide non-linear resistance valve plate (2) and The silicon carbide non-linear resistance valve plates (1) are connected in series to form a valve plate group, and each valve group is provided with upper and lower electrode taps (3), and the valve plate groups are sequentially installed on the bracket (4).

2. The novel generator rotor demagnetization and overvoltage protection device according to claim 1, characterized in that: the zinc oxide non-linear resistance valve plates (2) constituting the valve plate group are more than two pieces, silicon carbide One non-linear resistance valve plate (1).

3. The novel generator rotor demagnetization and overvoltage protection device according to claim 1 or 2, characterized in that: the silicon carbide non-linear resistance valve plate (1) is placed at one end of the valve plate group, and zinc oxide The non-linear resistance valve plate (2) is placed at the other end of the valve plate group.