CN209747409U

CN209747409U - High-power malfunction-prevention contactor type intermediate relay

Info

Publication number: CN209747409U
Application number: CN201920754785.XU
Authority: CN
Inventors: 张德继; 耿田军; 唐苏荣
Original assignee: Jiangsu Guoxin Huaian Second Gas Power Co Ltd
Current assignee: Jiangsu Guoxin Huaian Second Gas Power Co Ltd
Priority date: 2019-05-23
Filing date: 2019-05-23
Publication date: 2019-12-06
Anticipated expiration: 2029-05-23

Abstract

The utility model belongs to the technical field of auxiliary relay, especially, relate to a high-power maloperation prevention contactor formula auxiliary relay. The electromagnetic coil comprises a coil loop, wherein the coil loop comprises a wound electromagnetic coil, a power resistor and a normally closed main contact; the power resistor is connected in series with the normally closed main contact and then connected in parallel with the coil; before the coil loop acts, the coil and the power resistor carry current together, the power resistor absorbs main current, and the starting power of the coil loop is high; after the coil loop acts, the coil is electrified for a long time, the power resistor exits, and the power loss is low.

Description

High-power malfunction-prevention contactor type intermediate relay

Technical Field

The utility model belongs to the technical field of auxiliary relay, especially, relate to a high-power maloperation prevention contactor formula auxiliary relay

Background

The intermediate relay is widely applied to relay protection and automatic control systems to increase the number and capacity of contacts for transmitting intermediate signals in a control circuit. Nowadays, the control loop of the high-voltage switch of the transformer substation and the power plant generally consists of an operation box loop and a control loop of a high-voltage switch control cabinet, which are equipped in a protection cabinet. The intermediate relay is generally applied to the operation box tripping starting circuit, the tripping signal is opened to the outside of the operation box and contains more long-distance cables, for example, contact signals such as main transformer heavy gas and main transformer pressure release are transmitted to the operation box of the protection room from the main transformer body through the long-distance cables, the long-distance cables easily generate capacitance voltage or induction voltage, and the action voltage and the action power of the intermediate relay reaching the operation box tripping starting circuit can be mistakenly operated. With the rapid development of power system relay protection, the requirement for the misoperation prevention capability of the switch control circuit in the switch field area of the power system is higher and higher. Eighteen requirements of anti-accident measures of the national power grid are as follows: the external switch-in is directly started, and can be directly tripped without locking (such as non-electric quantity protection of a transformer and a reactor, remote tripping without local judgment and the like), or an intermediate relay with action voltage within 55-70% of rated direct-current power supply voltage is adopted at the start switch-in end and is required to have action power not lower than 5W once a tripping operation has a large influence (such as failure starting and the like) in an important loop limited by a limited locking condition. The intermediate relay which directly acts on tripping in the high-voltage switch protection and control loop of the transformer substation and the booster station of the power plant basically meets the requirement of the counter measure. In recent years, the accident of unit tripping caused by the mistaken tripping of a de-excitation switch of a generator excitation device is frequent, and the inspection shows that: and the external tripping of the magnetic switch is opened into a cable to generate induced voltage to cause the intermediate relay of the external tripping loop of the magnetic switch to malfunction. Under the background that the national grid company actively promotes the coordinated development of the grid source, the running stability of the generator set at the power supply side becomes more and more critical.

The normally open contact of the intermediate relay of the de-excitation switch tripping circuit of the excitation device needs to have certain through-current and arc extinguishing functions, so that the mature static intermediate relay applied in the microcomputer protection device is not suitable for use. At present, an intermediate relay of a tripping circuit of a field suppression switch of an excitation device is still mainly an electromagnetic intermediate relay, but the action power of the traditional electromagnetic intermediate relay is generally less than 1W. In order to increase the action power of the relay, the traditional method is to improve the processes of an electromagnetic coil and an iron core and reduce the impedance of the coil, and the defects are as follows: the relay has a large appearance and a high manufacturing cost.

SUMMERY OF THE UTILITY MODEL

an object of the utility model is to prior art's defect and not enough, provide a simple structure, reasonable in design, convenient to use's high-power mistake proofing contactor formula auxiliary relay promotes action power and avoids avoiding because of the produced induced voltage of long distance cable mistake and move to the design can bear the weight of heavy current and have the main contact of arc extinguishing ability.

In order to achieve the above object, the utility model adopts the following technical scheme: it contains auxiliary relay, its characterized in that: the intermediate relay consists of a power resistor, an intermediate relay coil, a group of normally open main contacts, a group of normally closed main contacts, a group of normally open auxiliary contacts and a group of normally closed auxiliary contacts; the power resistor is connected with the normally closed main contacts in the group of normally closed main contacts in series and then connected to form a branch circuit connected with the intermediate relay coil in parallel.

Preferably, the group of normally open main contacts and the group of normally closed main contacts are high-power control loops and contacts with arc extinguishing capability.

Preferably, the group of normally open auxiliary contacts and the group of normally closed auxiliary contacts are command and feedback signal contacts.

After the structure is adopted, the utility model discloses beneficial effect does: the power resistor and the normally closed main contact are connected in series to serve as a branch circuit connected with the coil in parallel, so that the power required by starting the intermediate relay is improved, and the possibility of misoperation caused by accumulated energy of induced voltage of the cable is greatly reduced; after the intermediate relay acts, the power resistor exits, long-time heat loss is avoided, the coil can be electrified for a long time after the intermediate relay acts, and at the moment, the coil current power is low, and the loss is low.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, 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 schematic diagram of the intermediate relay circuit of the present invention.

FIG. 2 is a switch on-off circuit diagram of the utility model

Description of reference numerals:

the relay switch comprises an intermediate relay coil K1, a power resistor RP, a normally closed main contact K21, a group of normally open main contacts 14, a group of normally closed main contacts 15, a group of normally open auxiliary contacts 16, a group of normally closed auxiliary contacts 17, an external closing control contact 21, a switch normally closed auxiliary contact 23, a switch closing coil YC, a switch normally open auxiliary contact 26, a switch opening coil YO, an external opening control contact 28 and an intermediate relay 29.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

Referring to fig. 1, the following technical solutions are adopted in the present embodiment: it contains intermediate relay 29, its characterized in that: the intermediate relay 29 consists of a power resistor RP, an intermediate relay coil K1, a group of normally open main contacts 14, a group of normally closed main contacts 15, a group of normally open auxiliary contacts 16 and a group of normally closed auxiliary contacts 17; the power resistor RP is connected in series with a normally closed main contact K21 in a group of normally closed main contacts 15 and then is connected to form a branch circuit connected in parallel with an intermediate relay coil K1 to form a coil loop; before the coil acts, the main current of the coil loop needs to be carried, the acting power of the coil loop is improved, the normally closed main contact is separated after the coil acts, the power resistor RP and the normally closed main contact K21 are connected in series, the branch is disconnected, namely the power resistor RP exits from the through-current power consumption loop after the intermediate relay coil K1 acts.

Before the intermediate relay coil loop acts, the intermediate relay coil K1 and the power resistor RP carry current together, the power resistor RP absorbs main current, only the intermediate relay coil K1 branch circuit is electrified after the intermediate relay coil loop acts, and long-term electrification technical requirements need to be met after the intermediate relay coil loop acts, so that the intermediate relay coil K1 has large impedance design and small power consumption; a group of normally open main contacts 14 and a group of normally closed main contacts 15 can be applied to a high-power control loop and contacts with arc extinguishing capability; a set of normally open auxiliary contacts 16 and a set of normally closed auxiliary contacts 17 may be used as command and feedback signals.

The impedance of the intermediate relay coil K1 is ZK1 ═ R1+ jWL, the resistance value of the power resistor RP is R2, after the power intermediate relay is operated, the power resistor exits the loop, and after the power intermediate relay is operated, the operating power operating voltage design UD ═ (60% -70%) UN is adjustable.

Example (b):

As shown in fig. 2, the present embodiment is applied to a control circuit in which a control power supply is a direct current, taking a control power supply Ud equal to 110VDC as an example, a direct current resistance value R1 equal to 4K Ω is designed in a coil K1 impedance, an inductive reactance in a direct current loop coil K1 impedance is zero, a power resistance value RP equal to R2 equal to 1K Ω, an intermediate relay rated power design UN equal to 110VDC, and an operating voltage design Ud equal to 60% UN, the intermediate relay operating power Pd equal to 5.445W. According to the above, when the power resistor exits the circuit after the operation of the intermediate relay, and the voltage maintains the rated voltage after the power operation after the operation, Py is 3W.

The external opening control contact 28 and the intermediate relay 29 of the present invention are connected in series to form an intermediate relay control loop; the intermediate relay normally-open main contact K11, the switch normally-open auxiliary contact K26 and the switch opening coil YO are connected in series to form a switch opening control loop, and the switch normally-open auxiliary contact K26 is used for opening and closing; the external opening control contact 21, the normally closed main contact K22, the switch normally closed auxiliary contact K23 and the switch closing coil YC are connected in series to form a switch closing control loop, and the normally closed main contact K22 and the switch normally closed auxiliary contact K23 are used for closing and locking. The brake opening process: when the switch is in a closing state, the intermediate relay coil K1 acts after the external opening control contact 28 is closed, the normally open main contact K11 is closed, the switch opening coil YO acts, and the switch is opened. A switching-on process: the switch is in a switching-off state, and after the external switching-off control contact 21 is closed, the switch switching-off coil YC acts to switch on the switch. Abnormal (false) action: the external opening control contact 28 cable generates induction voltage and applies to the intermediate relay 29, the intermediate relay coil K1 and the power resistor RP are connected in parallel for shunt, when the action voltage and the action power of the intermediate relay K1 are reached, the intermediate relay 29 acts, the normally open main contact K11 is closed, the opening loop acts, the switch is opened by mistake, the normally closed main contact K21 is opened, and the power resistor RP exits from the shunt loop.

The above description is only for the purpose of illustrating the technical solutions of the present invention and not for the purpose of limiting the same, and other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A high-power anti-malfunction contactor type intermediate relay comprises an intermediate relay (29), and is characterized in that: the intermediate relay (29) consists of a power Resistor (RP), an intermediate relay coil (K1), a group of normally open main contacts (14), a group of normally closed main contacts (15), a group of normally open auxiliary contacts (16) and a group of normally closed auxiliary contacts (17); the power Resistor (RP) is connected with a normally closed main contact (K21) in a group of normally closed main contacts (15) in series and then connected with a branch circuit connected with an intermediate relay coil (K1) in parallel to form a coil loop.

2. A high power anti-malfunction contactor type intermediate relay according to claim 1, characterized in that: the group of normally open main contacts (14) and the group of normally closed main contacts (15) are high-power control loops and contacts with arc extinguishing capability.

3. A high power anti-malfunction contactor type intermediate relay according to claim 1, characterized in that: the group of normally open auxiliary contacts (16) and the group of normally closed auxiliary contacts (17) are command and feedback signal contacts.