CN204349419U - Power-off trip protection plug - Google Patents

Abstract

The utility model discloses a power-off trip protection plug, which comprises an amplifier circuit, a release device, an over-temperature detection circuit, a rectifier diode, a power supply indicator circuit, a step-down circuit, a thyristor, a zero-sequence current transformer and a ground wire current The transformer is also provided with a phase loss protection circuit; the phase loss protection circuit includes an electromagnetic coil of the release, an anti-backflow diode, an energy storage capacitor, a first diode and a protection diode, and the positive pole of the energy storage capacitor is connected to the A reverse current diode and an electromagnetic coil, the negative pole of the protection diode is connected to the positive pole of the energy storage capacitor, the positive pole of the protection diode is connected to the other end of the electromagnetic coil, and the first diode is connected between the thyristor and the electromagnetic coil. The utility model realizes phase loss protection (including poor contact of L, N, and E phases), ground wire open circuit protection and wall electrified protection.

Description

Power-off trip protection plug

technical field

The utility model relates to the technical field of electricity safety protection, in particular to a power failure trip protection plug.

Background technique

The existing leakage protection technology mainly uses the neutral line (N) and the phase line (L) to pass through the zero-sequence mutual inductance line at the same time as a leakage protector, and the live wire detection (voltage detection and current detection) of the ground wire. The corresponding protection function can only be provided on the basis that the power supply voltage must continue to supply power. If the zero line of the power supply system is open or the contact is poor, when the ground line is charged or the insulation of the machine is abnormal, the protector will disconnect the system due to mechanical failure. Self-locking makes it impossible to reset the trip, the live voltage of the ground wire or the leakage current due to insulation damage will make the machine electrified, and if the human body touches it, it will cause an electric shock. This type of protector uses the power supply system to continuously attract the electromagnetic coil to make the contact of the tripping mechanism close to achieve the purpose of continuous power supply. To achieve the protection principle, the disadvantages of this protection method are: the continuous power supply of the electromagnetic coil causes the coil to heat up, and the long-term serious heating affects the service life of the protector and has potential safety hazards. Under extreme conditions, the protector will lose its protection function and cause serious consequences.

Utility model content

(1) Technical problems to be solved

The purpose of the utility model is to overcome the above disadvantages, aiming to provide a power-off trip protection plug.

(2) Technical solution

In order to solve the above problems, the utility model proposes a power-off trip protection plug, including an amplifier circuit, a trip unit, an over-temperature detection circuit, a rectifier diode, a power indicator circuit, a step-down circuit, a thyristor, and a zero-sequence current mutual inductance device and ground wire current transformer, and also has a phase loss protection circuit;

The open-phase protection circuit includes an electromagnetic coil of the release, an anti-backflow diode, an energy storage capacitor, a first diode and a protection diode, the anode of the energy storage capacitor is connected to the anti-backflow diode and the electromagnetic coil, and the cathode of the protection diode is Connect the positive pole of the energy storage capacitor, the positive pole of the protection diode is connected to the other end of the electromagnetic coil, and the first diode is connected between the thyristor and the electromagnetic coil;

A wall and ground protection circuit is also provided between the ground wire and the wall.

Further, the wall and ground wire protection circuit includes a first capacitor, a second capacitor, a second diode, a triode and a first protection resistor, one end of the first capacitor is connected to the ground wire, and the other end is connected to the second diode The positive electrode of the tube and the second capacitor, the other end of the second capacitor is connected to the wall, and the negative electrode of the second diode is connected to the base of the triode through the first protection resistor.

Further, the wall and ground wire protection circuit includes a third capacitor, a fourth capacitor, a ground voltage transformer and a transfer switch, one end of the third capacitor is connected to the wall, and the other end is connected to one end of the fourth capacitor and the ground wire The primary coil of the voltage transformer, the other end of the fourth capacitor is connected to the ground wire, and the ground wire voltage transformer and the ground wire current transformer are mutually switched by a switch.

Further, a live wire indication circuit is provided between the ground wire and the neutral wire.

Further, the primary coil of the zero-sequence current transformer is also provided with a test circuit.

(3) Beneficial effects

Compared with the prior art, the utility model has the following advantages: 1. Phase loss protection (including poor contact of L, N and E phases), the protector in the energized state will detect when the power supply of the L or N terminal is interrupted or the contact is poor. Transistor Q3 is cut off, the energy storage voltage of capacitor C5 passes through resistor R12, diode D6 conducts to thyristor SCR1, the electromagnetic coil pulls in, the mechanical self-locking contact is released, and the load power supply is cut off; , when the Eo terminal is open, the induced voltage on the E line passes through the capacitor C4, diode D3, resistor R6, transistor Q2, transistor Q1, diode D7 to the thyristor SCR1, the thyristor conducts, the electromagnetic coil pulls in, and the mechanical self-locking The contact is released to cut off the power supply of the load; 3. The wall is charged and protected in the energized state, the E terminal is not grounded, the ground wire Ee or Eo is charged, the charged current is sent to the resistor D7 after being detected and amplified, the SCR1 thyristor is turned on, and the electromagnetic coil Pulling in, the mechanical self-locking contact is released, and the power supply to the load is cut off.

Description of drawings

Fig. 1 is the schematic diagram of the circuit principle of Embodiment 1 of the power-off trip protection plug of the present invention;

Fig. 2 is a schematic diagram of the circuit principle of Embodiment 2 of the power-off trip protection plug of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment, the specific embodiment of the utility model is described in further detail. The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

Embodiment one

As shown in Figure 1, the utility model proposes a power-off tripping protection plug, including an amplifier circuit IC1, a release device, an over-temperature detection circuit, a rectifier diode D1, a power indicator circuit, and a step-down circuit composed of a resistor R4. Silicon-controlled SCR1, zero-sequence current transformer ZCT1 and ground current transformer ZCT3, wherein the over-temperature protection circuit is composed of voltage reference source, transistor Q1, resistors R7 to R9 and thermistor, and the power indicator circuit is composed of LED1 and Resistor R3 is connected in series, and there is also a phase loss protection circuit;

The phase loss protection circuit includes the electromagnetic coil L1 of the release, the anti-backflow diode D4, the energy storage capacitor C5, the first diode D6 and the protection diode D5, and the anode of the energy storage capacitor C5 is connected to the anti-backflow diode D4 and the electromagnetic Coil L1, the negative pole of the protective diode D5 is connected to the positive pole of the energy storage capacitor C5, the positive pole of the protective diode D5 is connected to the other end of the electromagnetic coil L1, and the first diode D6 is connected between the thyristor SCR1 and the electromagnetic coil L1;

A wall and ground protection circuit is also provided between the ground wire E and the wall Ee.

The wall and ground wire protection circuit includes a first capacitor C4, a second capacitor C3, a second diode D3, a transistor Q2 and a first protection resistor R6, one end of the first capacitor C4 is connected to the ground wire E, and the other end Connect the anode of the second diode D3 to the second capacitor C3, the other end of the second capacitor C3 is connected to the wall Ee, the cathode of the second diode D3 is connected to the base of the transistor Q2 through the first protection resistor R6 .

A ground wire charged indicating circuit is provided between the ground wire E and the neutral wire N, and the ground wire charged indicating circuit is composed of a capacitor C1, a resistor R1, and a neon lamp X1.

The primary coil of the zero-sequence current transformer ZCT1 is also provided with a test circuit, which is composed of a switch K1 and a resistor R2.

The circuit works as follows:

1 zero load, phase line leakage protection

After the protector plug is connected to the 220V input power supply, press the reset switch S1, S2 is closed, the working indicator LED1 is lit, the power supply voltage is rectified by D1, and D4 is reversely isolated to charge the C5 capacitor, and the voltage of C5 terminal is provided after the protection coil L1 The thyristor SCR1 is powered, and the thyristor is in the protection detection state; at the same time, the current is limited by the resistor R4, filtered by the C2 capacitor to supply power to IC1, and the protector is powered to work (this process is hereinafter referred to as: the protector is powered work); when the load terminal (output terminal) Lo or No outputs any leakage current, the mutual induction coil ZCT1 outputs the induced voltage, and one end is sent to pins 1 and 2 of the IC1 detection drive circuit after passing through ZCT3, when the leakage current reaches the preset value , the pin 7 outputs a high level via D2, D7 to the thyristor trigger pole, the thyristor conducts, the voltage of C5 terminal is applied to both ends of the electromagnetic coil of L1 instantly, and the coil pulls in to drive the tripping mechanism to close the contact (S2, S1) Disconnect, cut off the load power supply to play the role of safety protection;

2 Ground wire live protection (E end)

When the protector is powered on, the charged current of the ground wire flows out of the Eo terminal through E, and the induction coil ZCT3 which passes through the E wire outputs the induced voltage, and one path passes through ZCT1 and then is sent to pins 1 and 2 of IC1 respectively. When the leakage current reaches the preset When the value is high, pin 7 of IC1 outputs a high level and sends it to the SCR1 trigger pole through D2 and D7, the thyristor conducts, and the voltage of C5 terminal is applied to both ends of the electromagnetic coil of L1 instantly, and the coil pulls in to drive the tripping mechanism to close the contact. (S2, S1) is disconnected, cutting off the load power supply plays a role of safety protection;

3 phase loss protection (L or N phase loss)

When the protector is powered on, when the L or N terminals of the power supply are open or poorly connected (including the AC220V input terminal interrupting the power supply), the voltage at the C2 terminal is not enough to maintain the conduction of Q3. After Q3 is cut off, the voltage at the C5 terminal is sent to SCR1 through R12 and D6 When the trigger pole is turned on, the thyristor is turned on, and the voltage of C5 terminal is applied to both ends of the L1 electromagnetic coil instantly, and the coil pulls in to drive the trip mechanism to disconnect the closed contacts (S2, S1), and cut off the load power supply to play a role of safety protection;

4 phase loss protection (E, Eo phase loss)

When the protector is powered on, when the power supply E and Eo terminals are open, there will be an induced voltage on the E terminal, and the voltage will be sent to Q2 through C4, D3, R6 and turned on, Q1 will be turned on under control, and the power supply voltage will be sent to Q2 through Q1 After D7 triggers SCR1, the silicon controlled rectifier conducts, and the voltage of C5 terminal is applied to both ends of the electromagnetic coil of L1 instantly, and the coil pulls in to drive the tripping mechanism to disconnect the closed contacts (S2, S1), and cut off the load power supply for safety protection. effect;

5 Wall live protection (Ee end)

When the protector is powered on, the jumper at the input terminal x1 is preset to open circuit state, and x2 is short circuit state, the wall live voltage Ee is sent to Q2 through C3, D3, R6 and turned on, Q1 is controlled to turn on, and the power supply voltage is passed through Q1 After being sent to D7, SCR1 is triggered, the SCR is turned on, and the voltage of C5 terminal is applied to both ends of L1 electromagnetic coil instantly, and the coil pulls in to drive the tripping mechanism to disconnect the closed contacts (S2, S1), and cut off the load power supply to achieve safety. The function of protection is at the same time that the live warning light X1 is lit;

6 protector plug over temperature protection

When the protector is powered on and the over-temperature protection device detects that the temperature of the protector plug reaches the preset temperature, the C2 voltage is sent to U1 through R9 and RT1, and U1 is deeply turned on to cause Q1 to turn on, and the conduction current triggers SCR1 after passing through D7. The thyristor is turned on, and the voltage of C5 terminal is applied to both ends of the electromagnetic coil of L1 instantly, and the coil pulls in to drive the trip mechanism to disconnect the closed contacts (S2, S1), and cut off the load power supply to play a role of safety protection.

The utility model has the following advantages: 1. Phase loss protection (including poor contact of L, N and E phases), the protector in the electrified state, when the power supply of the L or N terminal is interrupted or the contact is poor, the detection transistor Q3 is cut off, and the capacitor C5 stores The energy voltage is turned on through the resistor R12, diode D6 to the thyristor SCR1, the electromagnetic coil is closed, the mechanical self-locking contact is released, and the load power supply is cut off; 2 open circuit protection, when the power is on, the grounding line E, Eo open circuit, E The induced voltage on the line passes through capacitor C4, diode D3, resistor R6, transistor Q2, transistor Q1, diode D7 to the thyristor SCR1, the thyristor is turned on, the electromagnetic coil is closed, the mechanical self-locking contact is released, and the load power supply is cut off ;3 Wall live protection power-on state, the E end is not grounded, the ground wire Ee end or Eo end is charged, the live current is sent to the resistor D7 after being detected and amplified, the SCR1 conducts, the electromagnetic coil pulls in, and the mechanical self-locking contact Click release to cut off the load power supply.

Embodiment two

The structure of this embodiment is basically the same as that of Embodiment 1, the difference is that as shown in Figure 2: the wall and ground protection circuit includes a third capacitor C3, a fourth capacitor C4, a ground voltage transformer ZCT2 and a transfer switch S3, one end of the third capacitor C3 is connected to the wall Ee, the other end is connected to one end of the fourth capacitor C4 and the primary coil of the ground voltage transformer ZCT2, the other end of the fourth capacitor C4 is connected to the ground E, and the ground The line voltage transformer ZCT2 and the ground line current transformer ZCT3 are mutually switched by the transfer switch S3. The phase loss protection (L or N phase loss) process of this embodiment is as follows: the protector is powered on, and when the power supply L or N terminal is open circuit or poor contact (including the interruption of power supply at the AC220V input terminal), the voltage of C2 terminal is not enough to maintain Q3 It is turned on, after Q3 is cut off, the voltage of C5 terminal is sent to the trigger pole of SCR1 through R12 and D6, the SCR is turned on, the voltage of C5 terminal is applied to both ends of the electromagnetic coil of L1 instantaneously, and the coil pulls in to drive the tripping mechanism to close the contact ( S2, S1) disconnect, cut off the load power supply to play the role of safety protection. Phase loss protection (E, Eo phase loss) is as follows: when the protector is powered on, when the power supply E and Eo terminals are open, there will be an induced voltage on the E terminal, which forms a loop through C4, ZCT2, R5 and N terminals, and ZCT2 senses The output voltage is sent to pins 1 and 2 of IC1 through S3 switching switch and ZCT1. After being amplified by IC1, pin 7 outputs a high level. After being sent to D7 through D2, SCR1 is triggered, the thyristor is turned on, and the voltage of C5 terminal is applied instantaneously. At both ends of the L1 electromagnetic coil, the coil pulls in and drives the tripping mechanism to disconnect the closed contacts (S2, S1) and cut off the load power supply to play a role of safety protection.

The above are only preferred embodiments of the present utility model, and it should be pointed out that for those of ordinary skill in the art, some improvements and modifications can also be made without departing from the technical principles of the present utility model. It should also be regarded as the protection scope of the present utility model.

Claims (5)

1. a power-off trip protection plug, comprise amplifying circuit, release, overtemperature testing circuit, rectifier diode, power supply indicator circuit, reduction voltage circuit, controllable silicon, zero sequence current mutual inductor and ground line current instrument transformer, it is characterized in that: be also provided with open-phase protection circuit;

Described open-phase protection circuit comprises solenoid, counterflow-preventing diode, storage capacitor, first diode of release and protects diode, described storage capacitor positive pole connects counterflow-preventing diode and solenoid, described protection diode cathode connects storage capacitor positive pole, protection diode cathode connects the other end of solenoid, and described first diode is connected between controllable silicon and solenoid;

Body of wall and ground wire protective circuit is also provided with between ground wire and body of wall.

2. power-off trip protection plug according to claim 1; it is characterized in that: described body of wall and ground wire protective circuit comprise the first electric capacity, the second electric capacity, the second diode, triode and the first protective resistance; described first electric capacity one end connects ground wire, the other end connects the second diode cathode and the second electric capacity; the other end connecting wall of described second electric capacity, the negative pole of described second diode passes through the base stage of the first protective resistance connecting triode.

3. power-off trip protection plug according to claim 1; it is characterized in that: described body of wall and ground wire protective circuit comprise the 3rd electric capacity, the 4th electric capacity, ground wire voltage instrument transformer and change over switch; described 3rd electric capacity one end connecting wall; the other end connects one end and the ground wire voltage primary winding of mutual inductor of the 4th electric capacity; the other end of described 4th electric capacity connects ground wire, and described ground wire voltage instrument transformer and ground line current instrument transformer are switched mutually by change over switch.

4. power-off trip protection plug according to claim 1 and 2, is characterized in that: be provided with ground wire electrification indicating circuit between described ground wire and zero line.

5. power-off trip protection plug according to claim 4, is characterized in that: the primary coil of described zero sequence current mutual inductor is also provided with test circuit.