A self-testing system for leakage protector

Abstract

The present invention discloses a self-checking system for a leakage protector, comprising a system power supply and crystal oscillator module, a power supply detection module, a phase and component self-checking module and a leakage protection driving module; the system power supply and crystal oscillator module is used to convert the first voltage input to the leakage protector into a second voltage to power the self-checking system and provide a clock signal; the power supply detection module is used to send a tripping signal to the leakage protection driving module when the external power supply is abnormal; the phase and component self-checking module is used to automatically check whether the AC phase and the external components of the leakage protector are working normally after power is turned on, and send a tripping signal to the leakage protection driving module when an abnormal situation occurs; the leakage protection driving module is used to control the external components of the leakage protector to trip when receiving the tripping signal. By adopting the embodiment of the present invention, the phase of the AC power and the external components of the leakage protector can be automatically and regularly tripped.

Description

Technical Field

[0001] The invention relates to the technical field of electric power safety, and in particular to a self-testing system for a leakage protector. Background Art

[0002] The leakage protector plays a very important role in the electrical system. It can effectively protect personal safety, prevent fire, and improve equipment reliability. It is also an essential equipment that meets safety standards and regulatory requirements. It plays an important role in the safety protection of low-voltage power grids.

[0003] However, the leakage protector commonly used at present is very easy to be damaged because its external components, especially the final-stage thyristor, need to generate a large current at the moment of tripping when leakage occurs. However, it is difficult to detect the damage in time, which may lead to safety hazards. Summary of the invention

[0004] The present invention provides a self-checking system for a leakage protector. By installing the self-checking system in the leakage protector, the phase of the alternating current and the external components of the leakage protector can be automatically and regularly self-checked for tripping, so as to solve the potential power safety problems of the existing leakage protector.

[0005] To solve the above technical problems, an embodiment of the present invention provides a self-test system for a leakage protector, comprising a system power supply and crystal oscillator module, a power supply detection module, a phase and component self-test module and a leakage protection drive module;

[0006] The input end of the system power supply and crystal oscillator module is electrically connected to the power supply voltage of the leakage protector through a bridge rectifier circuit; the output end of the system power supply and crystal oscillator module is electrically connected to the first input end of the power supply detection module, the first input end of the phase and component self-test module and the first input end of the leakage protection drive module; the second input end of the power supply detection module is electrically connected to the zero-sequence mutual inductor of the leakage protector; the output end of the power supply detection module is electrically connected to the second input end of the leakage protection drive module; the second input end of the phase and component self-test module is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the phase and component self-test module is electrically connected to the phase line through the magnetic suction coil of the leakage protector; the output end of the phase and component self-test module is electrically connected to the third input end of the leakage protection drive module; the output end of the leakage protection drive module is electrically connected to the thyristor switch of the leakage protector;

[0007] The system power supply and crystal oscillator module is used to convert the first voltage input to the leakage protector into a second voltage to power the self-test system, and provide a clock signal at the same time; the power detection module is used to send a trip signal to the leakage protection drive module when the external power supply is abnormal; the phase and component self-test module is used to automatically check whether the AC power phase and the external components of the leakage protector are working normally at regular intervals after power-on, and send a trip signal to the leakage protection drive module when an abnormal situation occurs; the leakage protection drive module is used to control the external components of the leakage protector to trip when receiving the trip signal.

[0008] As an improvement of the above solution, the system power supply and crystal oscillator module includes a Zener voltage regulator, a bandgap reference source and an oscillator unit;

[0009] The input end of the system power supply and crystal oscillator module is electrically connected to the input end of the Zener voltage regulator; the output end of the Zener voltage regulator is electrically connected to the first output end of the system power supply and crystal oscillator module, the input end of the bandgap reference source and the input end of the oscillator unit;

[0010] The first output end of the bandgap reference source is electrically connected to the second output end of the system power supply and crystal oscillator module; the second output end of the bandgap reference source is electrically connected to the third output end of the system power supply and crystal oscillator module; the third output end of the bandgap reference source is electrically connected to the fourth output end of the system power supply and crystal oscillator module;

[0011] The first output terminal of the oscillator unit is electrically connected to the system power supply and the fifth output terminal of the crystal oscillator module; the second output terminal of the oscillator unit is electrically connected to the system power supply and the sixth output terminal of the crystal oscillator module;

[0012] The first output terminal to the sixth output terminal of the system power supply and crystal oscillator module together constitute the output terminal of the system power supply and crystal oscillator module.

[0013] As an improvement on the above scheme, the outputs from the first output terminal to the fourth output terminal of the system power supply and crystal oscillator module are 5.1V, 2.5V, 1.8V and 1.2V voltages respectively; the outputs from the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module are 55KHz and 22KHz clock signals respectively.

[0014] As an improvement of the above solution, the power detection module includes an operational amplifier A0, a first comparator unit, a second comparator unit, delay circuit units D1-D2 and a first logic unit;

[0015] The in-phase input terminal and the inverting input terminal of the operational amplifier A0 are electrically connected to the two ends of the zero-sequence mutual inductor of the leakage protector respectively; the output terminal of the operational amplifier A0 is electrically connected to the first input terminal of the first comparator unit; the second input terminal of the first comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module; the output terminal of the first comparator unit is electrically connected to the delay circuit unit D1; the in-phase input terminal of the operational amplifier A0 is electrically connected to the first input terminal of the second comparator unit; the second input terminal of the second comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module; the output terminal of the second comparator unit is electrically connected to the input terminal of the delay circuit unit D2; the output terminal of the delay circuit D1 and the output terminal of the delay circuit D2 are both electrically connected to the input terminal of the first logic unit; the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module are both connected to the first logic unit; the output terminal of the first logic unit is electrically connected to the input terminal of the leakage protection driving module;

[0016] The operational amplifier A0 is used to amplify the voltage difference between its in-phase input terminal and the reverse input terminal; the first comparator unit and the second comparator unit are used to compare the voltage difference amplified by the operational amplifier A0 with the reference voltage provided by the output terminal of the system power supply and the crystal oscillator module; the delay circuit units D1~D2 are used to delay the comparison signal and send it to the first logic unit for calculation; the first logic unit is used to determine whether there is residual current in the zero-sequence transformer of the leakage protector according to the comparison signal.

[0017] As an improvement of the above solution, the first comparator unit includes comparators A1-A2;

[0018] The output end of the operational amplifier A0 is electrically connected to the non-inverting input end of the comparator A1 and the reverse input end of the comparator A2; the reverse input end of the comparator A1 is electrically connected to the system power supply and the third output end of the crystal oscillator module; the non-inverting input end of the comparator A2 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the output end of the comparator A1 and the output end of the comparator A2 are both electrically connected to the input end of the delay circuit unit D1.

[0019] As an improvement of the above solution, the second comparator unit includes comparators A3-A4;

[0020] The non-inverting input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A3; the reverse input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A4; the reverse input terminal of the comparator A3 and the reverse input terminal of the comparator A4 are both electrically connected to the fourth output terminal of the system power supply and crystal oscillator module; the output terminal of the comparator A3 and the output terminal of the comparator A4 are both electrically connected to the input terminal of the delay circuit unit D2.

[0021] As an improvement of the above solution, the delay circuit unit includes a NOR gate and a buffer connected in sequence.

[0022] As an improvement of the above solution, the phase and component self-checking module includes a power supply detection and switching unit, an AC state detection unit, a latch unit, a trigger unit, and an OR gate unit;

[0023] The first input end of the power detection and switching unit is electrically connected to the first output end of the system power supply and crystal oscillator module; the second input end of the power detection and switching unit is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the power detection and switching unit is electrically connected to the second output end of the system power supply and crystal oscillator module; the first output end of the power detection and switching unit is electrically connected to the first input end of the AC power state detection unit; the second input end of the AC power state detection unit is electrically connected to the phase line through the magnetic coil of the leakage protector; the output end of the AC power state detection unit is electrically connected to the input end of the latch unit and the input end of the trigger unit; the second output end of the power detection and switching unit and the output end of the latch are both electrically connected to the input end of the OR gate unit; the output end of the OR gate unit and the output end of the trigger are both electrically connected to the input end of the second logic unit; the sixth output end of the system power supply and crystal oscillator module is connected to the second logic unit; the output end of the second logic unit is electrically connected to the input end of the leakage protection driving module;

[0024] The power detection and switching unit is used to compare the phase of its second input terminal with the second output terminal of the system power supply and crystal oscillator module to obtain a phase detection result, and when the resistor and diode used to connect the second input terminal of the power detection and switching unit and the phase line are short-circuited, the power supply of the phase and component self-inspection module is switched to the first output terminal of the system power supply and crystal oscillator module; the combination of the AC power state detection unit and the latch unit is used to save the phase detection result; the second logic unit is used to process the signal passing through the OR gate and the trigger, and generate a trip signal when the external components work abnormally.

[0025] As an improvement of the above solution, the power detection and switching unit includes a PMOS tube, a first resistor, a second resistor and a comparator A5;

[0026] The drain of the PMOS tube is electrically connected to the system power supply and the first output end of the crystal oscillator module; the source of the PMOS tube is electrically connected to the input end of the phase line and the AC power state detection unit through a resistor and a diode connected in sequence; the source of the PMOS tube is grounded through a first resistor and a second resistor in sequence; the reverse input end of the comparator A5 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the same-direction input end of the comparator A5 is electrically connected to the first resistor at one end connected to the second resistor; the output end of the comparator A5 is electrically connected to the input end of the OR gate unit and the gate of the PMOS tube.

[0027] As an improvement of the above solution, the leakage protection driving module includes an SCR trigger unit, an NMOS tube and a third resistor;

[0028] The input end of the SCR trigger unit is electrically connected to the input end of the leakage protection driving module; the drain of the NMOS tube is electrically connected to the first output end of the SCR trigger unit, the first output end of the system power supply and crystal oscillator module, one end of the third resistor and the output end of the leakage protection driving module; the source of the NMOS tube and the other end of the third resistor are both grounded; the gate of the NMOS tube is electrically connected to the second output end of the SCR trigger unit.

[0029] Compared with the prior art, the present invention discloses a self-testing system for a leakage protector, which is electrically connected to the power supply voltage of the leakage protector through the input end of the system power supply and crystal oscillator module through a bridge rectifier circuit; the output end of the system power supply and crystal oscillator module is electrically connected to the first input end of the power supply detection module, the first input end of the phase and component self-testing module and the first input end of the leakage protection driving module; the second input end of the power supply detection module is electrically connected to the zero-sequence mutual inductor of the leakage protector; the output end of the power supply detection module is electrically connected to the second input end of the leakage protection driving module; the second input end of the phase and component self-testing module is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the phase and component self-testing module is electrically connected to the phase line through the magnetic suction coil of the leakage protector; the output end of the phase and component self-testing module is electrically connected to the third input end of the leakage protection driving module; the output end of the leakage protection driving module is electrically connected to the thyristor switch of the leakage protector. By adopting the embodiment of the present invention, the phase of the alternating current and the external components of the leakage protector can be automatically and regularly self-checked for tripping, so as to solve the potential power safety problem of the existing leakage protector. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a module schematic diagram of a self-test system for a leakage protector provided by an embodiment of the present invention;

[0031] Figure 2It is a structural schematic diagram of a system power supply and crystal oscillator module provided by an embodiment of the present invention;

[0032] Figure 3 is a structural schematic diagram of a power supply detection module provided by an embodiment of the present invention;

[0033] Figure 4 It is a structural schematic diagram of a phase and component self-checking module provided by an embodiment of the present invention;

[0034] Figure 5 It is a circuit structure diagram of a self-testing system for a leakage protector provided by an embodiment of the present invention;

[0035] Figure 6 The present invention provides a circuit structure diagram of applying a self-checking system for a leakage protector to the leakage protector. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the specification and claims, it is to be understood that the terms first, second, etc. in the specification and claims are only used for the purpose of describing the same technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated, nor necessarily describing the order or time sequence. The terms are interchangeable where appropriate. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0038] The principle of the existing leakage protector is that when the phase line and the neutral line are used improperly, there is an electric shock or the load-end electrical connection is improper, a residual current signal will be generated in the zero-sequence transformer connected to the phase line and the neutral line. When the residual current signal is detected, the external components connected to the phase line are controlled to disconnect. Generally, this is done by controlling the thyristor to generate a large current in the magnetic coil connected to the phase line, which then trips to achieve leakage protection for the entire circuit.

[0039] However, the applicant found that the leakage protector in the prior art cannot perform self-inspection regularly and timely, and it is difficult to eliminate faults. Safety hazards may occur due to damage to the leakage protector. In addition, the quality of the zero-sequence transformer used in the leakage protector is uneven, which can easily generate large interference signals at the input end of the leakage protector.

[0040] Based on the above considerations, the embodiment of the present invention improves the structure of the existing leakage protector and provides a self-checking system for the leakage protector. By installing the self-checking system in the leakage protector, the self-checking of tripping can be performed regularly and automatically, and the anti-interference characteristics of the leakage protector are improved, which is used to solve the potential power safety problems of the existing leakage protector.

[0041] See also Figure 1 In this embodiment, the self-test system 10 for the leakage protector includes a system power supply and crystal oscillator module 11, a power supply detection module 12, a phase and component self-test module 13 and a leakage protection drive module 14;

[0042] The input end of the system power supply and crystal oscillator module 11 is electrically connected to the power supply voltage of the leakage protector through a bridge rectifier circuit; the output end of the system power supply and crystal oscillator module 11 is electrically connected to the first input end of the power supply detection module 12, the first input end of the phase and component self-test module 13 and the first input end of the leakage protection drive module 14; the second input end of the power supply detection module 12 is electrically connected to the zero-sequence mutual inductor of the leakage protector; the output end of the power supply detection module 12 is electrically connected to the second input end of the leakage protection drive module 14; the second input end of the phase and component self-test module 13 is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the phase and component self-test module 13 is electrically connected to the phase line through the magnetic suction coil of the leakage protector; the output end of the phase and component self-test module 13 is electrically connected to the third input end of the leakage protection drive module 14; the output end of the leakage protection drive module 14 is electrically connected to the thyristor switch of the leakage protector;

[0043] The system power supply and crystal oscillator module 11 is used to convert the first voltage input to the leakage protector into a second voltage to power the self-test system, and provide a clock signal at the same time; the power supply detection module 12 is used to send a trip signal to the leakage protection drive module when the external power supply is abnormal; the phase and component self-test module 13 is used to automatically check the phase of the power supply regularly after power-on, and detect whether the external components in the circuit are working normally, and send a trip signal to the leakage protection drive module when an abnormal situation occurs; the leakage protection drive module 14 is used to control the external components of the leakage protector to trip when receiving the trip signal.

[0044] In some embodiments, the half-bridge rectifier unit includes a diode and a resistor.

[0045] It should be noted that the second voltage can be a plurality of different voltage values ​​to meet the power requirements of different ports; similarly, the clock signal can also be a plurality of different frequency values, and the specific value is set according to the self-test cycle.

[0046] For example, in the embodiment of the present invention, the output end of the leakage protection driving module 14 is electrically connected to one end of the magnetic coil through the thyristor switch of the leakage protector, and the other end of the magnetic coil is connected to the phase line. When the leakage protection driving module receives the tripping signal, it controls the opening of the thyristor switch, thereby generating a large current in the magnetic coil, and the large current acts on the magnetic head of the magnetic coil to achieve power-off tripping of the entire circuit.

[0047] In the above scheme, the system power supply and crystal oscillator module provide the self-test system with a second voltage and a clock signal to ensure the normal operation of each module. By electrically connecting the second input end of the power detection module with the zero-sequence mutual inductor of the leakage protector, the power supply voltage can be judged according to the residual current in the zero-sequence mutual inductor, that is, whether there is leakage between the phase line and the neutral line, so as to ensure the safety of the circuit. By electrically connecting the second input end of the phase and component self-test module with the phase line through the half-bridge rectifier unit of the leakage protector, the phase and component self-test module can be powered. In addition, by electrically connecting the output end of the system power supply and crystal oscillator module with the first input end of the phase and component self-test module, the normal operation of the phase and component self-test module can be guaranteed in the case of abnormal phase line power supply or half-bridge rectifier unit disconnection. Then, by electrically connecting the output end of the power detection module with the second input end of the leakage protection drive module, the output end of the phase and component self-test module is electrically connected to the third input end of the leakage protection drive module, so that when an abnormal situation occurs, the circuit can be cut off in time. By adopting the embodiments of the present invention, it is possible to regularly perform self-inspection of the leakage protector for tripping on the basis of ensuring the leakage protection function of the original leakage protector, and to check whether external components such as thyristors, zero-sequence mutual inductors and half-bridge rectifier units are working normally, thereby reducing the risk of electricity use.

[0048] As a preferred implementation, see Figure 2 , the system power supply and crystal oscillator module 11 includes a Zener voltage regulator, a bandgap reference source and an oscillator unit;

[0049] The input end of the system power supply and crystal oscillator module 11 is electrically connected to the input end of the Zener voltage regulator; the output end of the Zener voltage regulator is electrically connected to the first output end of the system power supply and crystal oscillator module 11, the input end of the bandgap reference source and the input end of the oscillator unit;

[0050] The first output terminal of the bandgap reference source is electrically connected to the second output terminal of the system power supply and crystal oscillator module 11; the second output terminal of the bandgap reference source is electrically connected to the third output terminal of the system power supply and crystal oscillator module 11; the fourth output terminal of the bandgap reference source is electrically connected to the fourth output terminal of the system power supply and crystal oscillator module 11;

[0051] The first output terminal of the oscillator unit is electrically connected to the system power supply and the fifth output terminal of the crystal oscillator module 11; the second output terminal of the oscillator unit is electrically connected to the system power supply and the sixth output terminal of the crystal oscillator module 11;

[0052] The first output terminal to the sixth output terminal of the system power supply and crystal oscillator module together constitute the output terminal of the system power supply and crystal oscillator module 11 .

[0053] Preferably, in some embodiments, the outputs from the first output terminal to the fourth output terminal of the system power supply and crystal oscillator module 11 are 5.1V, 2.5V, 1.8V and 1.2V voltages respectively; the outputs from the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module 11 are 55KHz and 22KHz clock signals respectively.

[0054] In some embodiments, the Zener voltage regulator includes a high-precision Zener diode and a high-precision operational amplifier. By setting the Zener voltage regulator, it is ensured that the power supply voltage of the internal circuit of the self-test system of the leakage protector is the voltage value of the system power supply and the first output terminal of the crystal oscillator module, which is 5.1V in the embodiment of the present invention; and it can provide power for the bandgap reference source and the oscillator unit.

[0055] It should be noted that, on the one hand, the system power supply and crystal oscillator module can convert the first voltage of the leakage protector into a second voltage to power each module in the self-test system for the leakage protector; on the other hand, the second voltage can also be used as a reference voltage to compare the voltage at a fixed point in the leakage protector with the second voltage to determine whether there is a leakage in the circuit.

[0056] In the above scheme, through the setting of the Zener voltage regulator, the bandgap reference source and the oscillator unit, a plurality of voltage values ​​of different sizes can be provided for the self-test system to meet different power supply or reference voltage requirements; two clock signals of different frequencies can also be provided for the self-test system, which can be used as clock signals to adjust the self-test cycle.

[0057] As a preferred implementation, see Figure 3 , the power detection module 12 includes an operational amplifier A0, a first comparator unit, a second comparator unit, delay circuit units D1-D2 and a first logic unit;

[0058] The in-phase input terminal and the inverting input terminal of the operational amplifier A0 are electrically connected to the two ends of the zero-sequence mutual inductor of the leakage protector respectively; the output terminal of the operational amplifier A0 is electrically connected to the first input terminal of the first comparator unit; the second input terminal of the first comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module 11; the output terminal of the first comparator unit is electrically connected to the delay circuit unit D1; the in-phase input terminal of the operational amplifier A0 is electrically connected to the first input terminal of the second comparator unit; the second input terminal of the second comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module 11; the output terminal of the second comparator unit is electrically connected to the input terminal of the delay circuit unit D2; the output terminal of the delay circuit D1 and the output terminal of the delay circuit D2 are both electrically connected to the input terminal of the first logic unit; the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module 11 are both connected to the first logic unit; the output terminal of the first logic unit is electrically connected to the input terminal of the leakage protection driving module;

[0059] The operational amplifier A0 is used to amplify the voltage difference between its in-phase input terminal and the reverse input terminal; the first comparator unit and the second comparator unit are used to compare the voltage difference amplified by the operational amplifier A0 with the reference voltage provided by the system power supply and the output terminal of the crystal oscillator module 11; the delay circuit units D1~D2 are used to delay the comparison signal and send it to the first logic unit for calculation; the first logic unit is used to determine whether there is residual current in the zero-sequence transformer of the leakage protector according to the comparison signal.

[0060] In the above scheme, when the leakage protector is connected to the phase line and the neutral line in an improper way, when an electric shock occurs or when the electrical connection of the load-end appliance is improper, a current difference will be generated, and a residual current will be generated in the zero-sequence transformer of the leakage protector. By electrically connecting the in-phase input terminal and the reverse input terminal of the operational amplifier A0 to the two ends of the zero-sequence transformer of the leakage protector respectively, the voltage difference can be amplified when there is a residual current between the zero-sequence transformers for subsequent analysis of the voltage difference signal. The first comparator unit can compare the amplified voltage difference with the reference voltage provided by the system power supply and the crystal oscillator module, and the second comparator unit can compare the voltage at one end of the zero-sequence transformer with the reference voltage provided by the system power supply and the crystal oscillator module; then the signal is delayed by the delay circuit units D1~D2 so that the signal is aligned; the first logic unit can output a trip signal according to the delayed signal to power off the circuit and protect the safety of the entire circuit.

[0061] Further, preferably, the first comparator unit includes comparators A1-A2;

[0062] The output end of the operational amplifier A0 is electrically connected to the non-inverting input end of the comparator A1 and the reverse input end of the comparator A2; the reverse input end of the comparator A1 is electrically connected to the system power supply and the third output end of the crystal oscillator module; the non-inverting input end of the comparator A2 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the output end of the comparator A1 and the output end of the comparator A2 are both electrically connected to the input end of the delay circuit unit D1.

[0063] Exemplarily, the first comparator unit compares the amplified voltage difference with reference voltages of 2.5V and 1.8V respectively.

[0064] Preferably, the second comparator unit includes comparators A3-A4;

[0065] The non-inverting input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A3; the reverse input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A4; the reverse input terminal of the comparator A3 and the reverse input terminal of the comparator A4 are both electrically connected to the fourth output terminal of the system power supply and crystal oscillator module; the output terminal of the comparator A3 and the output terminal of the comparator A4 are both electrically connected to the input terminal of the delay circuit unit D2.

[0066] Exemplarily, the second comparator unit compares the voltage at one end of the zero-sequence transformer with a reference voltage of 1.2V.

[0067] Furthermore, preferably, the delay circuit unit includes a NOR gate and a buffer connected in sequence.

[0068] It should be noted that in the delay circuit unit, the number of buffers does not affect the beneficial effects of the present invention, and the number of buffers is related to the delay time. Exemplarily, in an embodiment of the present invention, the delay circuit unit includes a two-input NOR gate and three buffers connected in sequence.

[0069] As a preferred implementation, see Figure 4 , the phase and component self-checking module 13 includes a power supply detection and switching unit, an AC state detection unit, a latch unit, a trigger unit, and an OR gate unit and a second logic unit;

[0070] The first input end of the power detection and switching unit is electrically connected to the first output end of the system power supply and crystal oscillator module 11; the second input end of the power detection and switching unit is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the power detection and switching unit is electrically connected to the second output end of the system power supply and crystal oscillator module 11; the first output end of the power detection and switching unit is electrically connected to the first input end of the AC power state detection unit; the second input end of the AC power state detection unit is electrically connected to the phase line through the magnetic coil of the leakage protector; the output end of the AC power state detection unit is electrically connected to the input end of the latch unit and the input end of the trigger unit; the second output end of the power detection and switching unit and the output end of the latch are both electrically connected to the input end of the OR gate unit; the output end of the OR gate unit and the output end of the trigger are both electrically connected to the input end of the second logic unit; the sixth output end of the system power supply and crystal oscillator module 11 is connected to the second logic unit; the output end of the second logic unit is electrically connected to the input end of the leakage protection driving module 14;

[0071] The power detection and switching unit is used to compare the phase of its second input terminal with the second output terminal of the system power supply and crystal oscillator module to obtain a phase detection result, and when the resistor and diode used to connect the second input terminal of the power detection and switching unit and the phase line are short-circuited, the power supply of the phase and component self-inspection module is switched to the first output terminal of the system power supply and crystal oscillator module; the combination of the AC power state detection unit and the latch unit is used to save the phase detection result; the second logic unit is used to process the signal passing through the OR gate and the trigger, and generate a trip signal when the external components work abnormally.

[0072] It should be noted that, in the embodiment of the present invention, by connecting the sixth output terminal of the system power supply and crystal oscillator module 11 to the second logic unit, the power supply detection and switching unit can automatically inspect the external components in each detection cycle.

[0073] It should also be noted that in the embodiment of the present invention, external components such as thyristors, zero-sequence transformers, and external half-bridge rectifier diodes can be periodically and automatically inspected. When an abnormal operation of an external component is detected, an abnormal signal can be output, such as controlling the disconnection of the overall circuit by outputting a trip signal. More preferably, the output end of the phase and component self-inspection module can also be electrically connected to a display unit, and the display unit includes a light-emitting diode or a display screen.

[0074] In the above scheme, the power supply detection and switching unit can ensure the normal and stable operation of the phase and component self-test module when the external power supply is abnormal, and can stabilize the working voltage of the phase and component self-test module at the same voltage as the first output terminal of the system power supply and crystal oscillator module; through the combination of the AC state detection unit and the latch unit, the state detection of the AC phase can be realized, and the state detection results of the positive phase and negative phase of the AC can be saved at the same time. The phase and component self-test module can automatically check the phase of the AC and the functions of the external components regularly according to the signal of the sixth output terminal of the system power supply and crystal oscillator module to ensure the further safe use of the electrical appliance.

[0075] Further, as a preferred implementation, the power detection and switching unit includes a PMOS tube, a first resistor, a second resistor and a comparator A5;

[0076] The drain of the PMOS tube is electrically connected to the system power supply and the first output end of the crystal oscillator module; the source of the PMOS tube is electrically connected to the phase line of the leakage protector and the input end of the AC power state detection unit through a resistor and a diode connected in sequence; the source of the PMOS tube is grounded through a first resistor and a second resistor in sequence; the reverse input end of the comparator A5 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the same-direction input end of the comparator A5 is electrically connected to the end of the first resistor connected to the second resistor; the output end of the comparator A5 is electrically connected to the input end of the OR gate unit and the gate of the PMOS tube.

[0077] In the above scheme, through the setting of a specific power supply detection and switching unit, when a half-bridge rectifier unit of the leakage protector fails and cannot supply power to the phase and component self-inspection module, the power supply of the phase and component self-inspection module can be automatically switched to the first output end of the system power supply and crystal oscillator module.

[0078] As a preferred implementation, the leakage protection driving module 14 includes an SCR trigger unit, an NMOS tube and a third resistor;

[0079] The input end of the SCR trigger unit is electrically connected to the input end of the leakage protection driving module; the drain of the NMOS tube is electrically connected to the first output end of the SCR trigger unit, the first output end of the system power supply and crystal oscillator module, one end of the third resistor and the output end of the leakage protection driving module; the source of the NMOS tube and the other end of the third resistor are both grounded; the gate of the NMOS tube is electrically connected to the second output end of the SCR trigger unit.

[0080] In some preferred embodiments, the self-test system for the leakage protector as described above is packaged as a chip, and the chip pins and the self-test system are connected to the circuit of the leakage protector as shown in FIG. Figure 5 and Figure 6 The packaged chip can realize all the above functions of the self-checking system for the leakage protector, and according to the chip design specification, several functional pins are designed to enable it to meet the electrical connection requirements of the leakage protector. The following is an analysis of a specific example of a self-checking system for a leakage protector provided by an embodiment of the present invention being applied to a leakage protector.

[0081] The alternating current provided by the phase and neutral wires is transmitted through Figure 6 The bridge rectifier circuit BR shown supplies power to the VDDR port of the chip. Inside the chip, the current passes through the VDDR port to power the Zener voltage source Zener, and the Zener voltage source Zener generates a high-precision 5.1V voltage to provide power to the system and the bandgap reference source Bandgap inside the crystal oscillator module, the oscillator unit OSC (the connection relationship between the oscillator unit OSC and the Zener voltage source Zener is not shown in the figure) and other modules of the self-test system.

[0082] Under normal use, if leakage occurs in the circuit, residual current will be generated in the zero-sequence transformer ZCT. After passing through the resistor R1, a voltage difference will be generated between the IN1 port and the IN2 port. The voltage difference is generally at the mV level. The voltage difference is then amplified by the signal amplifier Amp0 to obtain an amplified voltage difference signal; the amplified voltage difference signal is transmitted to the comparators Amp1 and Amp2 respectively, and compared with the 2.5V and 1.8V reference voltages generated by the bandgap reference source Bandgap, respectively, to obtain a pulse signal. The pulse signal is sent to the first delay unit Delay for a 20ms delay, and then the delayed signal is sent to the first logic unit Logic1 for calculation to obtain a trip signal. The trip signal generates a high-voltage signal to the SCR1 port through the leakage protection drive module. After the high-voltage signal passes through the thyristors Q1 and Q2, a large current is generated in the magnetic coil Ind, and then the power-off tripping of the entire circuit is realized through the magnetic head.

[0083] After power is turned on, the phase line passes through the magnetic coil Ind and the diode D2, and then through the resistor R8 and the diode D7 to provide a power supply voltage detection signal to the IN3 pin. The detection signal and the reference voltage Vref generated by the VDDT port are in the AC state detection unit ( Figure 6 The comparison and calculation are performed in the state detection described in the above to realize the state detection of the AC phase, wherein the resistor R8 and the diode D7 can detect both the positive phase and the negative phase of the AC phase and transmit the detection results to the latch unit for storage. It should be noted that when the positive phase of the AC is detected, the IN3 pin is designed as a low voltage signal; on the contrary, when the negative phase of the AC is detected, the IN3 pin is designed as a high voltage signal.

[0084] At the same time, the half-wave rectifier diode D1 and the limiting resistor R5 introduce the half-wave power supply from the phase line to the VDDT port, and after the resistor voltage division processing, the processed signal is sent to the power detection and switching unit of the phase and component self-test module, and the amplitude and phase are compared with the 2.5V voltage generated by the bandgap reference source module Bandgap in the power detection module, and the comparison result is sent to the OR gate unit, and sent to the second logic unit LOGIC2 after the OR gate processing together with the result of the detection of the phase of the AC power stored in the latch. If it is detected whether the diode D1 and R5 have an electrical circuit break, that is, when the power supply is abnormal, the PMOS tube in the power detection and switching unit is turned on, and the 5.1V output by the Zener voltage regulator is used as a backup power supply.

[0085] It should be noted that in the existing leakage protector, in order to ensure circuit safety, a filter capacitor needs to be added when the power supply voltage is connected to the leakage protector through a bridge rectifier circuit. However, with the embodiment of the present invention, since the self-detection system can detect external components and AC phase, the VDDR pin does not need to use a filter capacitor, which can save external components and make the circuit more in line with the actual UL943B standard.

[0086] It should also be noted that while detecting the negative phase of the alternating current, a 2ms high-level pulse signal is output from the Fault pin to drive the base of the transistor Q3, generating a current at the collector of the transistor Q3, and using the current as a simulated leakage current signal. After the simulated leakage current signal passes through the zero-sequence transformer ZCT and the resistor R1, a certain voltage difference is generated between the IN1 pin and the IN2 pin. It should be emphasized that the working mode at this time is not to detect the actual leakage current, but to determine whether residual current can be generated in the zero-sequence transformer ZCT when leakage current occurs between the neutral line and the phase line. Therefore, the high voltage signal generated by the SCR1 pin at this time is turned on. Figure 2 At the same time as the thyristors Q1 and Q2 shown in the figure, the IN3 pin is pulled down to a low level by the turned-on diode D7. The high-low conversion of the level of the IN3 pin is detected by the state and locked by the latch, and finally sent to the second logic unit LOGIC2 and the first logic unit LOGIC1 after the power supply detection through the OR gate. If all functional modules are working normally, the Alarm pin and the SCR1 pin output a low level; otherwise, a high level is output to light up the light-emitting diode D8 to alarm, and control the opening of the thyristors Q1 and Q2 to realize the tripping function, thereby completing the self-detection function of the entire circuit.

[0087] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A self-testing system for a leakage protector, characterized in that: Including system power supply and crystal oscillator module, power detection module, phase and component self-test module and leakage protection drive module; The input end of the system power supply and crystal oscillator module is electrically connected to the power supply voltage of the leakage protector through a bridge rectifier circuit; the output end of the system power supply and crystal oscillator module is electrically connected to the first input end of the power supply detection module, the first input end of the phase and component self-test module and the first input end of the leakage protection drive module; the second input end of the power supply detection module is electrically connected to the zero-sequence mutual inductor of the leakage protector; the output end of the power supply detection module is electrically connected to the second input end of the leakage protection drive module; the second input end of the phase and component self-test module is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the phase and component self-test module is electrically connected to the phase line through the magnetic suction coil of the leakage protector; the output end of the phase and component self-test module is electrically connected to the third input end of the leakage protection drive module; the output end of the leakage protection drive module is electrically connected to the thyristor switch of the leakage protector; The system power supply and crystal oscillator module is used to convert the first voltage input to the leakage protector into a second voltage to power the self-test system, and provide a clock signal at the same time; the power detection module is used to send a trip signal to the leakage protection drive module when the external power supply is abnormal; the phase and component self-test module is used to automatically check whether the AC power phase and the external components of the leakage protector are working normally at regular intervals after power-on, and send a trip signal to the leakage protection drive module when an abnormal situation occurs; the leakage protection drive module is used to control the external components of the leakage protector to trip when receiving the trip signal.

2. A self-testing system for a leakage protector as claimed in claim 1, characterized in that: The system power supply and crystal oscillator module includes a Zener voltage regulator, a bandgap reference source and an oscillator unit; The input end of the system power supply and crystal oscillator module is electrically connected to the input end of the Zener voltage regulator; the output end of the Zener voltage regulator is electrically connected to the first output end of the system power supply and crystal oscillator module, the input end of the bandgap reference source and the input end of the oscillator unit; The first output end of the bandgap reference source is electrically connected to the second output end of the system power supply and crystal oscillator module; the second output end of the bandgap reference source is electrically connected to the third output end of the system power supply and crystal oscillator module; the third output end of the bandgap reference source is electrically connected to the fourth output end of the system power supply and crystal oscillator module; The first output terminal of the oscillator unit is electrically connected to the system power supply and the fifth output terminal of the crystal oscillator module; the second output terminal of the oscillator unit is electrically connected to the system power supply and the sixth output terminal of the crystal oscillator module; The first output terminal to the sixth output terminal of the system power supply and crystal oscillator module together constitute the output terminal of the system power supply and crystal oscillator module.

3. A self-testing system for a leakage protector as claimed in claim 2, characterized in that: The outputs of the first output terminal to the fourth output terminal of the system power supply and crystal oscillator module are 5.1V, 2.5V, 1.8V and 1.2V voltages respectively; the outputs of the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module are 55KHz and 22KHz clock signals respectively.

4. A self-testing system for a leakage protector as claimed in claim 2, characterized in that: The power detection module includes an operational amplifier A0, a first comparator unit, a second comparator unit, delay circuit units D1-D2 and a first logic unit; The in-phase input terminal and the inverting input terminal of the operational amplifier A0 are electrically connected to the two ends of the zero-sequence mutual inductor of the leakage protector respectively; the output terminal of the operational amplifier A0 is electrically connected to the first input terminal of the first comparator unit; the second input terminal of the first comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module; the output terminal of the first comparator unit is electrically connected to the delay circuit unit D1; the in-phase input terminal of the operational amplifier A0 is electrically connected to the first input terminal of the second comparator unit; the second input terminal of the second comparator unit is electrically connected to the output terminal of the system power supply and crystal oscillator module; the output terminal of the second comparator unit is electrically connected to the input terminal of the delay circuit unit D2; the output terminal of the delay circuit unit D1 and the output terminal of the delay circuit unit D2 are both electrically connected to the input terminal of the first logic unit; the fifth output terminal and the sixth output terminal of the system power supply and crystal oscillator module are both connected to the first logic unit; the output terminal of the first logic unit is electrically connected to the input terminal of the leakage protection driving module; The operational amplifier A0 is used to amplify the voltage difference between its in-phase input terminal and the reverse input terminal; the first comparator unit and the second comparator unit are used to compare the voltage difference amplified by the operational amplifier A0 with the reference voltage provided by the output terminal of the system power supply and the crystal oscillator module; the delay circuit units D1~D2 are used to delay the comparison signal and send it to the first logic unit for calculation; the first logic unit is used to determine whether there is residual current in the zero-sequence transformer of the leakage protector according to the comparison signal.

5. A self-testing system for a leakage protector as claimed in claim 4, characterized in that: The first comparator unit includes comparators A1-A2; The output end of the operational amplifier A0 is electrically connected to the non-inverting input end of the comparator A1 and the reverse input end of the comparator A2; the reverse input end of the comparator A1 is electrically connected to the system power supply and the third output end of the crystal oscillator module; the non-inverting input end of the comparator A2 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the output end of the comparator A1 and the output end of the comparator A2 are both electrically connected to the input end of the delay circuit unit D1.

6. A self-testing system for a leakage protector as claimed in claim 5, characterized in that: The second comparator unit includes comparators A3-A4; The non-inverting input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A3; the reverse input terminal of the operational amplifier A0 is electrically connected to the non-inverting input terminal of the comparator A4; the reverse input terminal of the comparator A3 and the reverse input terminal of the comparator A4 are both electrically connected to the fourth output terminal of the system power supply and crystal oscillator module; the output terminal of the comparator A3 and the output terminal of the comparator A4 are both electrically connected to the input terminal of the delay circuit unit D2.

7. A self-testing system for a leakage protector as claimed in claim 4, characterized in that: The delay circuit unit includes a NOR gate and a buffer which are connected in sequence.

8. A self-testing system for a leakage protector as claimed in claim 4, characterized in that: The phase and component self-checking module includes a power supply detection and switching unit, an AC state detection unit, a latch unit, a trigger unit, and an OR gate unit and a second logic unit; The first input terminal of the power detection and switching unit is electrically connected to the first output terminal of the system power supply and crystal oscillator module; The second input end of the power detection and switching unit is electrically connected to the phase line through the half-bridge rectifier unit of the leakage protector; the third input end of the power detection and switching unit is electrically connected to the second output end of the system power supply and crystal oscillator module; The first output end of the power detection and switching unit is electrically connected to the first input end of the AC state detection unit; the second input end of the AC state detection unit is electrically connected to the phase line through the magnetic coil of the leakage protector; the output end of the AC state detection unit is electrically connected to the input end of the latch unit and the input end of the trigger unit; the second output end of the power detection and switching unit and the output end of the latch are electrically connected to the input end of the OR gate unit; the output end of the OR gate unit and the output end of the trigger are electrically connected to the input end of the second logic unit; the sixth output end of the system power supply and crystal oscillator module is connected to the second logic unit; the output end of the second logic unit is electrically connected to the input end of the leakage protection driving module; The power detection and switching unit is used to compare the phase of its second input terminal with the second output terminal of the system power supply and crystal oscillator module to obtain a phase detection result, and when the resistor and diode used to connect the second input terminal of the power detection and switching unit and the phase line are short-circuited, the power supply of the phase and component self-inspection module is switched to the first output terminal of the system power supply and crystal oscillator module; the combination of the AC power state detection unit and the latch unit is used to save the phase detection result; the second logic unit is used to process the signal passing through the OR gate and the trigger, and generate a trip signal when the external components work abnormally.

9. A self-testing system for a leakage protector as claimed in claim 8, characterized in that: The power detection and switching unit includes a PMOS tube, a first resistor, a second resistor and a comparator A5; The drain of the PMOS tube is electrically connected to the system power supply and the first output end of the crystal oscillator module; the source of the PMOS tube is electrically connected to the input end of the phase line and the AC power state detection unit through a resistor and a diode connected in sequence; the source of the PMOS tube is grounded through a first resistor and a second resistor in sequence; the reverse input end of the comparator A5 is electrically connected to the system power supply and the second output end of the crystal oscillator module; the same-direction input end of the comparator A5 is electrically connected to the first resistor at one end connected to the second resistor; the output end of the comparator A5 is electrically connected to the input end of the OR gate unit and the gate of the PMOS tube.

10. A self-testing system for a leakage protector as claimed in claim 9, characterized in that: The leakage protection driving module includes an SCR trigger unit, an NMOS tube and a third resistor; The input end of the SCR trigger unit is electrically connected to the input end of the leakage protection driving module; the drain of the NMOS tube is electrically connected to the first output end of the SCR trigger unit, the first output end of the system power supply and crystal oscillator module, one end of the third resistor and the output end of the leakage protection driving module; the source of the NMOS tube and the other end of the third resistor are both grounded; the gate of the NMOS tube is electrically connected to the second output end of the SCR trigger unit.

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