CN110783152A - Locking shunt release - Google Patents

Abstract

The invention discloses a locking shunt release, which comprises a time-controlled full-wave rectifying circuit, a trigger time-delay circuit, a controllable switching circuit and a double-coil electromagnet, wherein the double-coil electromagnet comprises a static iron core, a double-coil winding and a movable iron core. The power input is rectified full-wave direct current or half-wave direct current voltage through the controllable full-wave rectifying circuit, the voltage provides working power for the double-coil electromagnet, meanwhile, a voltage signal is provided for the trigger delay circuit, the trigger delay circuit provides a switch control signal for the controllable switch circuit, the controllable switch circuit controls the connection and disconnection of a starting winding in the double coils, the double-coil electromagnet comprises a starting winding and a maintaining winding, and the maintaining winding is always grounded. The invention has the characteristics of simple circuit, easy realization, wide applicable voltage range, high reliability and the like.

Description

Locking shunt release

Technical Field

The invention belongs to the technical field of low-voltage circuit breakers, and particularly relates to a locking shunt release.

Background

The shunt release is an accessory for remotely controlling the shunt, and is based on the 2 nd part of GB14148.1-2006 general rules for low-voltage switchgear and control equipment and GB 14048.2-2008 for low-voltage switchgear and control equipment: circuit breaker specifies that the shunt release should trip to open the electrical appliance under all operating conditions of the electrical appliance when the supply voltage of the shunt release (measured during the tripping action) remains between 70% and 110% of the nominal grid voltage. In view of the above general rules, it is required that the trip unit should operate reliably when the applied power supply voltage is between 70% and 110% of the rated voltage. When the applied power supply voltage is below 70% of the rated voltage, the shunt release cannot act.

The ideal opening process is usually a telemechanical opening process. And (3) for the remote control shunt (the shunt release is electrified), the circuit breaker is switched off and kept in the shunt state to avoid reclosing until the remote control instruction is removed (the shunt release is electrified).

The existing shunt release has the technical defects that firstly, a simple circuit is used for controlling the working mode of an electromagnet, the simple circuit can act when being electrified, the input power voltage is low, the acting force of the electromagnet is small, and the shunt release and the shunt brake cannot be reliably released; and the other is similar to the technical scheme disclosed by CN201320072566.6 (shunt release), the shunt process is only a pulse period process, the pulse period is over, and the shunt action is over at the same time (although the shunt release is still powered), so that a possibility of reclosing is provided. Thirdly, similar to the technical scheme disclosed in CN 104681370A (a dual-coil shunt release), the circuit is complex, the debugging is difficult, and the current spike is easy to produce during the process of maintaining the winding voltage by PWM modulation, so that the conduction or radiation index exceeds the standard.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the pulse-type action process of the existing common shunt release is overcome, and the movable iron core in the shunt double-coil electromagnet is always in a shunt-lock state in the range that the input voltage meets the national standard, so that reclosing is effectively prevented; the problems that an existing double-coil shunt release is complex in circuit, prone to exceeding the standard of electrical performance indexes, weak in anti-interference capacity and the like are solved.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the locking shunt release comprises a controllable full-wave rectifying circuit, a trigger time-delay circuit, a controllable switching circuit and a double-coil electromagnet, wherein the double-coil electromagnet comprises a static iron core, a double-coil winding and a movable iron core.

The power input is rectified full-wave direct current or half-wave direct current voltage by the controllable full-wave rectifying circuit, the voltage provides working power for the double-coil electromagnet, and provides voltage signals for the trigger delay circuit, the trigger delay circuit provides switch control signals for the controllable switch circuit, the controllable switch circuit controls the connection and disconnection of the starting winding in the double coils, the double-coil electromagnet comprises the starting winding and the maintaining winding, and the maintaining winding is always grounded.

Further, the controllable full-wave rectification circuit rectifies the input power supply voltage into full-wave direct current for a period of time and then automatically converts the full-wave direct current into half-wave direct current. The switching of the full-wave direct current or the half-wave direct current is controlled by the input voltage, if the input voltage of the power supply is more than 0.7Ue, the rectified output is full-wave direct current and automatically converted into half-wave direct current after lasting for tens of milliseconds, and when the input voltage of the power supply is less than 0.7Ue, the half-wave direct current is always output.

Furthermore, the trigger time delay circuit sends a pulse trigger signal to the controllable switch circuit under the action of full-wave voltage. The trigger delay circuit comprises various comparator circuits, an MCU circuit, a TL431 combined circuit, a pulse transformer type circuit and the like.

Further, the controllable switching circuit is used for controlling a starting winding in the double-coil electromagnet. The main elements in the controllable switch current can be MOS tube, silicon controlled rectifier, relay, etc.

Furthermore, the (shunt-excited) double-coil electromagnet comprises a static iron core (shell), a movable iron core, a double-coil winding, a return spring and the like. The double-coil winding comprises a starting winding and a maintaining winding, the number of turns of the starting winding is small, the wire diameter is thick, the working current is large, when the voltage of a power grid is larger than 70% of the rated voltage, the movable iron core of the electromagnet can be ensured to be popped out-shunt by independently electrifying, the number of turns of the maintaining winding is large, the wire diameter is thin, the working current is small, the working current is always grounded, the movable iron core of the shunt electromagnet is reliably maintained in a shunt tripping state under the action of the starting winding, and the magnetic field force of the maintaining winding is insufficient due to insufficient power obtained until the voltage of the power grid is smaller than 30% of the rated voltage, so that the movable iron core is automatically reset to. The maintaining winding is always grounded, and a direct path is formed for surge pulse, pulse group pulse and the like in the input voltage of the power supply, so that the high anti-interference capability is achieved.

The invention has the characteristics of simple circuit, easy realization, wide applicable voltage range, high reliability and the like.

Drawings

Fig. 1 is a circuit schematic diagram of a locking shunt release of the present invention;

FIG. 2 is an embodiment of a clocked full wave rectifier circuit;

FIG. 3 is another embodiment of a time-controlled full-wave rectifier circuit;

fig. 4 is an embodiment of a lock-up shunt release.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

The locking shunt release comprises a controllable full-wave rectifying circuit, a trigger time-delay circuit, a controllable switching circuit and a double-coil electromagnet, wherein the double-coil electromagnet comprises a static iron core, a double-coil winding, a movable iron core and the like.

An embodiment of a main portion of a lock-up shunt release is described with reference to fig. 1 below.

After the power supply input exceeds 0.7Ue, full-wave direct current and half-wave direct current voltages distributed according to time sequence are rectified by the controllable full-wave rectification circuit, the voltages provide working power supply for the double-coil electromagnet, meanwhile, voltage signals are provided for the trigger delay circuit, the trigger delay circuit provides switch control signals for the controllable switch circuit, the controllable switch circuit controls the connection and disconnection of a starting winding in the double coils, the double-coil electromagnet comprises a starting winding and a maintaining winding, and the maintaining winding is always grounded. Because the maintaining winding is always grounded, working current is obtained after the output voltage of the full-wave rectifying circuit is controlled in a time mode, and the movable iron core can be kept at a fixed position through magnetic force generated by the working current. Under the action of the trigger delay circuit-controllable switch circuit, the start winding is electrified for tens of milliseconds, the start winding obtains large current, and the strong magnetic force forces the movable iron core to move to the end point. In the shunt start phase, the start winding and the sustain winding act together in the same direction (end of the same name). And then, the movable iron core keeps the movable iron core at the end position under the action of the magnetic force of the maintaining winding to realize the shunt locking function, and the electromagnetic force in the maintaining winding is not enough to overcome the reset spring force until the input voltage of the voltage power supply is reduced to be below 0.3Ue, so that the movable iron core is reset to the original state.

Fig. 2 is a main configuration of a time-controlled full-wave rectifier circuit. The power input is connected to the two ends L and N, and the two ends L and N are connected with a piezoresistor RV1 in parallel and used for suppressing the peak voltage from the power input. Diodes D1, D2, D3 and D4 constitute a basic full-wave rectifier circuit, and the output voltage is defined as VH. An NMOS tube Q1 is connected between the N end and the anode of the D4 in series, the N end is connected with a hysteresis comparator through a current limiting resistor R1 to provide working current and comparison voltage, the reference negative end of the hysteresis comparator is connected with the anode of the D4, and the output end of the hysteresis comparator is connected with the grid of the Q1. When the power input is positive (L end) and negative (N end), D1 is conducted, after the current flows through the load, the current is conducted from the Ground (GND) to the N end through D3, and the positive half cycle is conducted; when the power input is positive (L terminal) negative (N terminal), whether Q1 is turned on or not depends on the level of the power input voltage value due to the presence of Q1. When the input voltage of the power supply is greater than 0.7Ue, the hysteresis comparator sends a high-level pulse signal to Q1, Q1 is conducted, D4 is isolated, and the negative half cycle is conducted. Therefore, when the input voltage of the power supply is lower than 0.7Ue, the output voltage VH of the time-controlled full-wave rectification circuit is half-wave voltage; when the input voltage is greater than 0.7Ue, the output voltage VH is a half-wave voltage after tens of milliseconds of full-wave voltage.

Figure 3 is a schematic diagram of the principal components of another simpler clocked full wave rectifier circuit. The power input is connected to the two ends L and N, and the two ends L and N are connected with a piezoresistor RV1 in parallel and used for suppressing the peak voltage from the power input. The diodes D1, D2, D3 and the one-way thyristor D4 form a basic full-wave rectifying circuit, and the output voltage is defined as VH. When the power input is positive (L end) and negative (N end), D2 is conducted, current flows through the load, then is conducted to the L end from the Ground (GND) through D3, and the negative half cycle is conducted; when the power input is positive (terminal L), negative (terminal N), D1 is turned on, and after the current flows through the load, it returns to terminal N through D4 from Ground (GND), since whether D4 is turned on depends on its trigger voltage. During the positive half-cycle conduction period from the power-on, the voltage value at the C1 is zero, the current charges the C1 through the D1 and the current-limiting resistor R1, meanwhile, the current flows through the resistors R3 and R2, the D4 is conducted, and the VH obtains full-wave voltage. As the minute current passing through R1 is charged into C1, the voltage at C1 is reduced, and the divided voltage value formed by R3 and R2 is reduced until the final divided voltage value is lower than the trigger voltage of D4, and D4 is turned off.

Fig. 4 is a main structure of a practical locking shunt release. The virtual frame I is a time control full wave rectification circuit, the virtual frame II is a trigger time delay circuit, the MOS tube Q4 is a controllable switch circuit, the winding L1 in the double-coil electromagnet DCT is a starting winding and is controlled by Q4, and the L2 is a maintaining winding and is always grounded. After power-on, the input voltage of the power supply controls the voltage VH generated by the full-wave rectification circuit through the virtual frame I, and directly supplies power to the maintaining winding to establish the magnetic field of the maintaining winding. The voltage dependent resistor RV1 is used for suppressing spike interference from power supply input voltage, the principle of the virtual frame I time control full wave rectification circuit is similar to that in FIG. 2, when the power supply input voltage is positive (N end) and positive (L end) and negative, due to PMOS transistor Q1

The gate voltage depends on the state of the voltage comparator Q2(TL 431). The half-wave voltage is divided by resistors R1 and R2 and then isolated by D4, and the diode D2 returns to the L terminal through the Ground (GND). If the half-wave voltage is lower than 0.7Ue, the Q2 outputs a high-resistance state, the resistor R3 is pulled up to a high level, and the grid voltage of the Q1 is high and is not conducted. If the half-wave voltage is greater than 0.7Ue, the divided voltage value is greater than the reference comparison voltage of Q2, Q2 flips output low level, Q1 grid voltage becomes low to turn on output, and the main current is isolated to VH by D4. After the Q2 is turned over, the R3 charges the capacitor C2, the charging voltage rises continuously, and when the voltage is higher than the gate voltage of the Q1, the Q1 is cut off. The capacitor C1 is connected in parallel with the two ends of the R2, and serves to smooth the divided voltage value. In the trigger delay circuit of the virtual frame II, the resistors R4 and R5 divide the VH voltage, and compare with the reference voltage of the voltage comparator Q3(TL431), the smoothing capacitor C3 is connected in parallel to the two ends of R5, only when the VH voltage is full-wave voltage and exceeds 0.7Ue, the divided value of the R4 and R5 to the VH voltage is greater than the reference voltage of Q3, Q3 flips to output low level, the triode Q4 is cut off to output high level, the gate of the NMOS Q5 gets high level to be turned on, and the start winding L1 starts large current. Under the action of large current of the starting winding, the movable iron core moves to a terminal (shunt) state. With the lapse of time, the R6 charges the C4, the voltage of the C4 is gradually increased to a certain value, the Q4 is conducted, the Q5 is cut off, and the starting process of the electromagnet is finished. Because the winding is always grounded, the magnetic field force generated by the current keeps the movable iron core at the end position, and the shunt locking function is realized. When the input voltage of the power supply is reduced to be lower than 0.3Ue, the magnetic field force generated by the current in the winding is maintained and is not enough to overcome the spring force, and the movable iron core returns to the original position under the action of the spring force reset force.

In light of the foregoing, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims (7)

1. The locking type shunt release is characterized in that: the double-coil electromagnet comprises a controllable time control full-wave rectifying circuit, a trigger time delay circuit, a controllable switching circuit and a double-coil electromagnet, wherein the double-coil electromagnet comprises a static iron core, a double-coil winding and a movable iron core;

the power input is rectified full-wave direct current or half-wave direct current voltage through the controllable full-wave rectifying circuit, the voltage provides working power for the double-coil electromagnet, meanwhile, a voltage signal is provided for the trigger delay circuit, the trigger delay circuit provides a switch control signal for the controllable switch circuit, the controllable switch circuit controls the connection and disconnection of a starting winding in the double coils, the double-coil electromagnet comprises a starting winding and a maintaining winding, and the maintaining winding is always grounded.

2. The lock-stopping shunt release according to claim 1, wherein: the controllable full-wave rectification circuit rectifies input power supply voltage into full-wave direct current for t time and then automatically converts the full-wave direct current into half-wave direct current; the switching of the full-wave DC or the half-wave DC is controlled by the level of the input voltage; when the input voltage of the power supply is higher than U, the rectified output is full-wave direct current and automatically turns into half-wave direct current after lasting for tens of milliseconds, and when the input voltage of the power supply is lower than U, the half-wave direct current is always output.

3. The lock-stopping shunt release according to claim 1, wherein: the value of U is 0.7 Ue.

4. The lock-stopping shunt release according to claim 1, wherein: the trigger time delay circuit sends a pulse trigger signal to the controllable switch circuit under the action of full-wave voltage.

5. The lock-stopping shunt release according to claim 1, wherein: the trigger delay circuit comprises various comparator circuits, an MCU circuit, a TL431 combined circuit and a pulse transformer type circuit.

6. The lock-stopping shunt release according to claim 1, wherein: the controllable switch circuit is used for controlling a starting winding in the double-coil electromagnet; the main element in the controllable switch current comprises a MOS tube, or controllable silicon, or a relay.

7. The lock-stopping shunt release according to claim 1, wherein: the double-coil electromagnet comprises a static iron core, a movable iron core, a double-coil winding and a return spring; the double-coil winding comprises a starting winding and a maintaining winding, the number of turns of the starting winding is small, the wire diameter is thick, the working current is large, the number of turns of the maintaining winding is large, the wire diameter is thin, and the working current is small; under the action of half-wave voltage, the magnetic energy provided by the maintaining winding can keep the movable iron core in a shunt state until the power supply voltage is reduced to be below 0.3Ue, and the movable iron core is reset to an initial state under the action of a reset spring force.

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