CN2171941Y

CN2171941Y - Solid-state phase lacking protective relay

Info

Publication number: CN2171941Y
Application number: CN 93226440
Authority: CN
Inventors: 陈根芳
Original assignee: Shanghai Institute of Organic Chemistry of CAS
Current assignee: Shanghai Institute of Organic Chemistry of CAS
Priority date: 1993-10-16
Filing date: 1993-10-16
Publication date: 1994-07-13
Anticipated expiration: 2003-10-16

Abstract

The utility model relates to a solid-state phase lacking protective relay. An SCR is controlled by an input power supply via a three-phase balancing network to a current trigger, so that the current of a three-phase half-wave rectifying controller which is connected with the three-phase balancing network provides controllable current for a light emitting diode via an SCR1. The light emitting diode and the SCR2 of a complete output circuit are connected into a switching annunciator. The utility model has the advantages of small size, no spark, non contacts, long service life, corrosion prevention and vibration prevention, and is suitable for the 380V and the 220V terminal voltages of a switch.

Description

Solid-state phase lacking protective relay

The utility model is a kind of solid-state open-phase protection relay; be mainly used in monitoring and control protection to the three-phase alternating current phase failure; as with A.C. contactor, when thermal relay is used, can play protection fast and effectively because of phase shortage to Y type or △ type three-phase AC asynchronous motor.

Three phase electric machine is worked mutually because of scarce (breaking) and is often burnt out motor; so; people constantly study open-phase protection relay; commercially available DQ-S or Y type electric appliance series protector can be applicable to be protected because of the phase failure Y type or △ three-phase AC asynchronous motor; but this protector volume is big; the motor main circuit string need be adjusted during use and produces many troubles in protector.Tang Yongfa had once reported " lack of water and phase-lacking protective device automatically " (electronics newspaper, the 32nd phase second edition, on August 9th, 1992), and this protective device need become the input power source transition voltage of 12V and increase relay, also need add auxiliary relay simultaneously.Newly introduced a kind of novel solid-state phase failure relay (electronics newspaper week; the 51st phase second edition; on December 20th, 1992); but this phase failure relay is only applicable to input voltage 380V; output (switch terminals) voltage 220V; the scope of application is less, also circuit is not further described simultaneously.So simple and easy solid-state open-phase protection relay applied widely is still the problem that people constantly explore.

The utility model is a kind of solid-state open-phase protection relay that provides at the defective of above-mentioned relay.

The principle of solid-state open-phase protection relay of the present utility model is that the input power supply is connected serially to the current trigger device through the three-phase equilibrium network, control unidirectional controllable silicon S CR ₁, make the electric current of the three phase half wave rectification controller that is connected with the three-phase equilibrium network pass through SCR ₁Provide a controllable current to MOC, the SCR on a MOC and the complete output loop ₂Connect into switching signal.

Solid-state open-phase protection relay of the present utility model can further describe as follows: three-phase circuit passes through R ₁, R ₂And R ₃Resistance constitute the three-phase equilibrium network, this network is connected with the current trigger device, DB in the current trigger device ₃, capacitor C ₁And L ₁The loop is to go here and there on the three-phase equilibrium network, passes through L ₁Coupling is passed to L ₂Produce pulse signal, again by rectifier diode D ₄Rectification, capacitor C ₂Charging control SCR ₁Trigger current, with three-phase equilibrium network and SCR ₁The centre that links to each other also has one by resistance R ₄, R ₅And R ₆And rectifying tube D ₁, D ₂And D ₃Form the three phase half wave rectification controller circuitry, work as SCR ₁During conducting, can make the three-phase semiwave electric current pass through SCR ₁Provide a controllable current to MOC, the output in MOC and the solid-state open phase protector, four rectifying tube D of bidirectional triode thyristor SSR ₅, D ₆, D ₇And D ₈The bridge heap of forming, SCR ₂And R ₇A complete output conducting that is constituted is connected, specifically, and MOC and SCR ₂Negative electrode with control the utmost point be connected.When three-phase equilibrium network phase shortage is right, be short-circuit condition for the MOC output, can make SCR ₂End fast, lead only that SSR ends, have auto-lock function.L wherein ₁And L ₂It can be ferrite bead.

The utility model not only volume is little; can be used protection motor safety work, no-spark, contactless, long service life, corrosion-resistant, anti-vibration easily with A.C. contactor; and because switch terminals voltage of the present utility model can 380V or 220V, two kinds of voltages are all general.So also be the A.C. contactor of 380V applicable to the CJO potential winding, therefore, the scope of application is also wide.

Can further understand the utility model by following embodiment.

Fig. 1 is a kind of circuit diagram of solid-state open-phase protection relay.

Fig. 2 is a kind of enforcement figure of solid-state open-phase protection relay.

Fig. 3 is a kind of oblique view of solid-state open-phase protection relay.

Among the figure 1,2,3-input three phase mains contact, 4,5-exports switch contact, 0-three-phase equilibrium mesh current tie point, 6-ground signalling, 7-shell, the potential winding of C-A.C. contactor, D-motor.

Fig. 1 is the circuit diagram of a kind of solid-state open phase protector of the present utility model.Three phase mains can be imported from 1,2 and 3 contacts respectively, and by R ₁, R ₂And R ₃Constitute three-phase network, the three-phase equilibrium network is by 0 and C ₁, CB ₃And L ₁Loop and L ₂, D ₄, C ₂And SCR ₁The current trigger device that constitutes is connected, by the resistance R that links to each other with three-phase and balancing network ₄, R ₅And R ₆And rectifier D ₁, D ₂And D ₃The three-phase half wave retifier and the SCR that constitute ₁Be connected, again by light-emitting diode MOC with by

output

4 and 5 and SSR, D ₅, D ₆, D ₇, D ₈, SCR ₁And R ₇The negative electrode of SCR is connected with the control utmost point in the output loop of forming, by MOC and SCR ₂Form a control switch.Output of the present utility model can be 220V or 380V.

When input current balance, balanced voltage O point is 0, if lack (breaking) phase time, the O point is not 0 voltage, to C ₁Dash electricity, when voltage is higher than DB ₃The time conducting, by L ₁Coupling is passed to L ₂Produce pulse signal, pass through D ₄Rectification is to C ₂Dash electricity, work as C ₂Voltage is greater than SCR ₁Trigger voltage the time, trigger voltage makes SCR ₁Conducting.Thereby make the three-phase semiwave electric current pass through SCR ₁To the MOC power supply, make it be conducting state, and then cause SCR in the output loop ₂The negative electrode and the control utmost point produce short circuit, make SCR ₂End, lead only that SSR ends, close output.

When adopting the utility model; three phase mains is by the contact of a fuse and an A.C. contactor; feed in the electric motor loop through thermoelectric device respectively; solid-state phase failure relay input and on the three-phase of motor; solid-state phase failure relay output switch terminals is gone here and there respectively on the potential winding (C) and push-button switch of A.C. contactor, and as shown in Figure 2, Fig. 3 is an oblique view of the present utility model; a kind of plate face with continuing on the end face, so that by dress.

Claims

1, a kind of solid-state open-phase protection relay that contains the three-phase equilibrium network, it is characterized in that the three-phase equilibrium network in succession with current trigger device, unidirectional controllable silicon S CR ₁Series connection, the electric current that makes the three phase half wave rectification controller that is connected with the three-phase equilibrium network is by unidirectional controllable silicon S CR ₁Provide a controllable current to MOC, the unidirectional controllable silicon S CR on this MOC and the complete output loop ₂Connect into switching signal.

2, a kind of solid-state open-phase protection relay as claimed in claim 1 is characterized in that described current trigger device is by diac DB ₃, capacitor C ₁And L ₁The loop string passes through L on the three-phase equilibrium network ₁Coupling is passed to L ₂Produce pulse signal, again by rectifies, capacitor C ₂Charging control unidirectional controllable silicon S CR ₁Trigger current constitute.

3, a kind of solid-state open-phase protection relay as claimed in claim 1 is characterized in that described three-phase half wave retifier is made up of three half-wave rectifiers, and each half-wave rectifier is to be in series by resistance and rectifying tube.

4, a kind of solid-state open-phase protection relay as claimed in claim 1 is characterized in that the bridge heap that described complete output conducting is made up of output, bidirectional triode thyristor, four rectifying tubes forms the loop, and this bridge is piled and the single-phase silicon-controlled SCR that links to each other with MOC respectively ₂, resistance R ₇Form the loop.

5, a kind of as claim 2,3 and 4 described solid-state open-phase protection relays, it is characterized in that described L ₁And L ₂It is ferrite bead.