CN113206495A - Leakage protection device, electric connection equipment and electrical appliance - Google Patents

Abstract

An earth leakage protection device comprising: the leakage current detection module detects a leakage current signal on a power supply circuit and generates a detection feedback signal when the leakage current signal is detected, and the power supply circuit supplies power to the power supply circuit in a half cycle of alternating current; and a self-test module which detects whether the leakage current detection module malfunctions based on the detection feedback signal, and includes: the analog leakage current generation module generates an analog leakage current signal so as to simulate the leakage current signal; the fault signal generation module generates a self-checking fault signal when the leakage current detection module fails; and the self-checking compensation module provides an additional working power supply for the leakage current detection module, so that the leakage current detection module is ensured to be in a working state when the analog leakage current signal is generated. The self-checking module provides an additional working power supply for the leakage current detection module, so that misjudgment can be avoided.

Description

Leakage protection device, electric connection equipment and electrical appliance

Technical Field

The disclosure belongs to the field of electrical, and particularly relates to an electric leakage protection device with a self-checking compensation module, an electric connection device and an electric appliance.

Background

Currently, for consideration of various factors such as cost and reliability, a half-bridge rectification scheme is adopted in a power supply part of a leakage current detection module of most leakage protection devices. Therefore, such a leakage protection device detects a leakage current signal on the power supply line only in a half cycle of the alternating current, that is, its operating period is a half cycle of the alternating current. When the self-test function is added to such an earth leakage protection device, since the time for generating the analog leakage current signal by the self-test module has uncertainty, for example, may be generated at the edge of the working half cycle or in the non-working half cycle of the leakage current detection module, even if the leakage current detection module does not fail, the analog leakage current signal may not be detected normally and a detection feedback signal is generated, which causes the self-test module to erroneously determine that the leakage current detection module fails, thereby disconnecting the electrical connection of the earth leakage protection device.

Disclosure of Invention

In view of the above, the present disclosure provides an electrical leakage protection device having a self-checking compensation module for providing an additional operating power supply to a leakage current detection module, so as to ensure that the leakage current detection module is in an operating state when an analog leakage current signal is generated. Therefore, the self-checking module can reliably complete self-checking when triggering the self-checking function at any time, and the occurrence of misjudgment is avoided.

A first aspect of the present disclosure provides an earth leakage protection device comprising: the leakage current detection module is configured to detect a leakage current signal on a power supply line and generate a detection feedback signal when the leakage current signal is detected, and the power supply line supplies power to the leakage current detection module in a half cycle of alternating current; a self-test module configured to detect whether the leakage current detection module malfunctions based on the detection feedback signal, the self-test module including: an analog leakage current generation module configured to generate an analog leakage current signal to simulate the leakage current signal; a fault signal generation module configured to generate a self-test fault signal when the leakage current detection module fails; and the self-checking compensation module is configured to provide an additional working power supply for the leakage current detection module, so as to ensure that the leakage current detection module is in a working state when the analog leakage current signal is generated.

In a preferred embodiment, the self-test compensation module comprises: an energy storage module configured to store electrical energy obtained from a power supply line; and a power coupling element configured to couple the energy storage module to a power circuit of the leakage current detection module to provide power to the leakage current detection module.

In a preferred embodiment, the energy storage module comprises a first resistor and a first capacitor connected in series, the power supply line charges the first capacitor via the first resistor, and the first capacitor is configured to provide power to the leakage current detection module via the power coupling element.

In a preferred embodiment, the power coupling element is selected from one or more of the following: a unidirectional conducting element, a controllable semiconductor element and a resistor.

In a preferred embodiment, the self-test module further comprises: an analog leakage trigger module configured to generate an analog leakage trigger signal; and a trigger signal closing module configured to close the analog leakage trigger signal under the action of the detection feedback signal, wherein the analog leakage current generating module generates the analog leakage current signal through the triggering of the analog leakage trigger signal, and the fault signal generating module is coupled to the analog leakage trigger module.

In a preferred embodiment, the first capacitor supplies power or stops supplying power to the leakage current detection module in response to generation and shutdown of the analog leakage trigger signal.

In a preferred embodiment, the analog leakage trigger module comprises a trigger tube, one end of which is coupled between the first resistor and the first capacitor, and the other end of which is coupled to the power coupling element, and generates an analog leakage trigger signal when the trigger tube is turned on.

In a preferred embodiment, the first capacitor supplies power to the leakage current detection module during the entire period of the alternating current.

In a preferred embodiment, the analog leakage trigger module, the analog leakage current generation module, the trigger signal shutdown module, the fault signal generation module and the self-checking compensation module are all composed of discrete electronic components.

In a preferred embodiment, the earth leakage protection device further comprises a fault response module configured to send a fault indication message and/or disconnect the power connection on the power supply line under the effect of the self-test fault signal.

A second aspect of the present disclosure proposes an electrical connection apparatus, characterized in that it comprises: a housing; and an earth leakage protection device according to any of the embodiments of the first aspect, said earth leakage protection device being accommodated in said housing.

A third aspect of the present disclosure provides an electrical appliance, wherein the electrical appliance includes: a load device; and an electrical connection device coupled between a power supply line and the load device for supplying power to the load device, wherein the electrical connection device comprises the earth leakage protection device according to any one of the embodiments of the first aspect.

In the disclosure, the self-checking compensation module provides an additional working power supply for the leakage detection module, so that the self-checking module can reliably complete self-checking when triggering a self-checking function at any time, and misjudgment is avoided.

Drawings

Embodiments are shown and described with reference to the drawings. These drawings are provided to illustrate the basic principles and thus only show the aspects necessary for understanding the basic principles. The figures are not to scale. In the drawings, like reference numerals designate similar features. In addition, lines drawn between each block in the architecture diagram indicate that there is electrical coupling between the two blocks, and the absence of a line drawn between the two blocks does not indicate that the two blocks are not coupled.

Fig. 1 shows an architecture diagram of a leakage protection device according to an embodiment of the present disclosure;

fig. 2 shows a schematic architecture diagram of a leakage protection device according to a first embodiment of the present disclosure;

fig. 3 shows a schematic view of an earth leakage protection device according to a second embodiment of the present disclosure;

fig. 4 shows a schematic view of an earth leakage protection device according to a third embodiment of the present disclosure; and

fig. 5 shows a schematic view of an earth leakage protection device according to a fourth embodiment of the present disclosure.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Before describing embodiments of the present disclosure, some terms referred to in the present disclosure are first explained to better understand the present disclosure. In the present disclosure, a transistor may refer to a transistor of any structure, such as a Field Effect Transistor (FET), a Bipolar Junction Transistor (BJT), or a thyristor, etc. When the transistor is a field effect transistor, the control electrode of the transistor refers to a grid electrode of the field effect transistor, the first electrode can be a drain electrode or a source electrode of the field effect transistor, and the corresponding second electrode can be a source electrode or a drain electrode of the field effect transistor; when the transistor is a bipolar transistor, the control electrode of the transistor refers to the base electrode of the bipolar transistor, the first electrode can be the collector electrode or the emitter electrode of the bipolar transistor, and the corresponding second electrode can be the emitter electrode or the collector electrode of the bipolar transistor; when the transistor is a thyristor, the control electrode of the transistor is the control electrode G of the thyristor, the first electrode is an anode, and the second electrode is a cathode. The analog leakage current signal is a periodic signal generated by the self-checking module and has a short duration, so that although the leakage detecting module can detect the analog leakage current signal, the leakage protection device is not required to be disconnected from the power supply.

The disclosure is directed to an electric leakage protection device, in which a self-checking module includes a self-checking compensation module, which can provide an additional working power supply for an electric leakage detection module, so as to ensure that the self-checking module can reliably complete self-checking when triggering a self-checking function at any time, thereby avoiding misjudgment.

Fig. 1 shows an architecture diagram of a leakage protection device according to an embodiment of the present disclosure.

As shown in fig. 1, earth leakage protection device 100 includes leakage current detection module 1, self-test module 2, and fault response module 3. The leakage current detection module 1 is coupled between the input end and the output end of the power supply line and is used for detecting whether a leakage current signal exists on the power supply line. The power supply line supplies alternating current between its input terminals and supplies the leakage current detection module 1 with power during a half cycle of the alternating current. The self-checking module 2 is coupled to the power supply line and the leakage current detection module 1, and is used for periodically generating an analog leakage current signal so as to detect whether the leakage current detection module 1 fails. The self-test module 2 comprises an analog leakage current trigger module 21, an analog leakage current generation module 22, a trigger signal shutdown module 23, a fault signal generation module 24 and a self-test compensation module 25. The analog leakage trigger module 21 is used for periodically generating an analog leakage trigger signal. The analog leakage current generating module 22 is coupled to the analog leakage trigger module 21, receives the analog leakage trigger signal, and generates an analog leakage current signal by triggering the analog leakage trigger signal, where the analog leakage current signal simulates a leakage current signal on a power supply line. Therefore, when the analog leakage current signal is generated, the leakage current detection module 1 detects the analog leakage current signal and generates a detection feedback signal. The detection feedback signal is provided to the trigger signal shutdown module 23. The trigger signal closing module 23 closes the analog leakage trigger signal under the action of the detection feedback signal, thereby closing the analog leakage signal. The fault signal generation module 24 is coupled to the analog leakage trigger module 22 to monitor whether the analog leakage trigger signal is turned off. When the leakage current detection module 1 fails and the analog leakage trigger signal cannot be turned off, the fault signal generation module 24 generates a self-test fault signal and provides the self-test fault signal to the fault response module 3. The self-checking compensation module 25 is coupled to the leakage current detection module 1 and provides an additional working power supply for the leakage current detection module 1, thereby ensuring that the leakage current detection module 1 is in a working state when the analog leakage current signal is generated. The fault response module 3 is coupled between the input and the output of the power supply line and disconnects the power connection on the power supply line under the effect of a self-checking fault signal. In other embodiments, fault response module 3 may also issue fault indication information such as an audible/visual alarm under the influence of a self-test fault signal.

In some embodiments, the self-test compensation module 25 further includes an energy storage module and a power coupling element (not shown in fig. 1). The energy storage module is used for storing electric energy obtained from a power supply line, and the power supply coupling element is used for coupling the energy storage module to a power supply circuit of the leakage current detection module 1 so as to provide electric energy for the leakage current detection module 1.

In some embodiments, the energy storage module comprises a first resistor and a first capacitor connected in series. The power supply line charges the first capacitor through the first resistor. The power supply line can supply power to the leakage current detection module 1 and charge the first capacitor in a half cycle of alternating current. Alternatively, the supply line may charge the first capacitor during the entire cycle of the alternating current. The first capacitor is used for providing electric energy to the leakage current detection module 1 through the power coupling element.

In some embodiments, the power coupling element is selected from one or more of: a unidirectional conducting element, a controllable semiconductor element and a resistor. The unidirectional conducting element includes, but is not limited to, a diode, and the controllable semiconductor element includes, but is not limited to, a trigger diode, a bipolar transistor, a field effect transistor, a thyristor, a photocoupler, etc.

Fig. 2 shows a schematic architecture diagram of a leakage protection device according to a first embodiment of the present disclosure.

As shown in fig. 2, the earth leakage protection device 200 is coupled between the input LINE and the LOAD equipment LOAD. The leakage current detection module 1 includes a leakage detection coil CT1 through which a power supply line passes and a processor U1. The fault response module comprises a switch module 31 and a driver module 32. The switch module 31 includes a switch SW1 and a RESET switch RESET for controlling the switching of the power connection of the power supply line. The drive module 32 includes a switching drive element (e.g., a solenoid SOL) and two transistors Q1, Q2. Hot line (L) is coupled through resistor R1 to pin 3 of processor U1, which powers processor U1 on the positive half cycle of alternating current.

When leakage detection is performed in the leakage protection device 200, both the switch SW1 and the RESET switch RESET are closed. When the live (L) and neutral (N) lines are current balanced, the leakage detection loop CT1 does not produce a current imbalance. When there is an imbalance of current flowing through the power supply line of the leakage detection coil CT1, i.e. there is a leakage current signal, a corresponding induced voltage will be generated on the leakage detection coil CT 1. The leakage detection coil CT1 is coupled to pins 4, 5 and 6 of the processor U1, and pin 1 of U1 outputs a high level when the voltage output by the leakage detection coil CT1 is greater than a threshold value, and otherwise outputs a low level. The high level at pin 1 of processor U1 is provided to transistors Q1 and Q2, causing transistors Q1 and/or Q2 to turn on, which in turn causes a current change in the coil of solenoid SOL to create a magnetic field that causes switch SW1 and RESET to open, thereby disconnecting the power on the supply line.

With continued reference to fig. 2, self-test module 2 includes an analog leakage trigger module 21, an analog leakage current generation module 22, a trigger signal shutdown module 23, a fault signal generation module 24, and a self-test compensation module 25. Referring to fig. 2, in the present embodiment, the self-test compensation module 25 includes a first resistor R01 and a first capacitor C01 connected in series, and a diode D02. The analog leakage trigger module 21 includes a trigger tube D01. One end of the trigger D01 is connected to the node a between the first resistor R01 and the first capacitor C01, and the other end is connected to the anode of the diode D02. The cathode of diode D02 is connected to pin 3 of processor U1. The trigger tube D01 generates an analog leakage trigger signal when conducting, which can be any electronic element with a voltage threshold as a trigger condition. In the present embodiment, the first resistor R01 and the first capacitor C01 are used not only to provide additional operating power to the processor U1 via the diode D02, but also to control the conduction of the trigger transistor D01, so as to control the interval of generating the analog leakage trigger signal. The resistance value of the first resistor R01 and the capacitance value of the first capacitor C01 may be set according to the magnitude of the supply voltage required by the processor U1 and the desired interval time for generating the analog leakage trigger signal. The analog leakage current generation module 22 includes a second resistor R02 coupled to the trigger D01. The hot line (L) is coupled to the first capacitor C01 through the diode D11 and the first resistor R01, and charges the first capacitor C01 during the positive half cycle of the alternating current. When the upper plate potential of the first capacitor C01 (the potential at the node a) reaches the trigger voltage of the trigger tube D01, the trigger tube D01 is turned on, so that an analog leakage current signal is generated through the second resistor R02 and flows through the leakage current detection coil CT 1. It can be understood that the analog leakage current signal is a current actively generated by the self-test module 2, and is used for simulating a leakage current signal generated when a power supply line fails. At the same time, the first capacitor C01 also powers the processor U1 through the diode D02. Thus, the first capacitor C01 provides additional operating power for the U1 while generating the analog leakage trigger signal and the analog leakage signal. Therefore, even if the analog leakage trigger signal and the analog leakage current signal are generated on the positive half cycle edge or the negative half cycle of the alternating current (the power supply line does not provide the operating power to the U1), since the self-checking compensation module 25 provides the additional operating power to the processor U1, the U1 is also in the operating state, and the analog leakage current signal can be detected without failure.

In case the leakage current detection module 1 is not malfunctioning, it detects the analog leakage current signal and generates a detection feedback signal. Specifically, the leakage detection coil CT1 detects the analog leakage current signal generated by the analog leakage current generation module 22, and generates an induced voltage. When the voltage output by the leakage detection coil CT1 is greater than the threshold, pin 1 of the processor U1 outputs a high level, i.e., a detection feedback signal. The detection feedback signal is provided to the trigger signal shutdown module 23. The trigger signal shutdown module 23 includes a first semiconductor element. In the present embodiment, the first semiconductor element is implemented as a transistor Q01. The high level output from pin 1 of U1 turns on the transistor Q01, thereby providing a path for discharging the charge on the first capacitor C01, and further turning off the analog leakage trigger signal, i.e., the voltage of the top plate of the first capacitor C01 is lower than the trigger voltage of the trigger transistor D01, and turning off the trigger transistor D01. Accordingly, the analog leakage current signal is no longer generated across the second resistor R02, and the first capacitor C01 also no longer provides additional operating power to U1.

The fault signal generation module 24 includes a third resistor R03 and a second capacitor C02 connected in series. When the leakage current detection module 1 fails and the analog leakage trigger signal cannot be turned off, the second capacitor C02 generates a self-test failure signal. Specifically, the third resistor R03 and the second capacitor C02 are connected in series and then connected in parallel with the second resistor R02. The intermediate node B of the third resistor R03 and the second capacitor C02 is connected to the transistors Q1 and Q2 in the driving module 32 via a diode D12. As described above, the analog leakage current signal is generated via the triggering of the analog leakage trigger signal. At the same time, a current will also flow through the third resistor R03, and this current continues to charge the second capacitor C02. Under the condition that the leakage current detection module 1 does not have a fault, the leakage current detection module generates a detection feedback signal when detecting the analog leakage current signal, and further closes the analog leakage current trigger signal and the analog leakage current signal. Since the analog leakage current signal lasts for a short time, the upper plate potential of the second capacitor C02 (the potential at the node B) is not sufficient to drive the transistors Q1 and Q2. However, when the leakage current detecting module 1 fails, the leakage current detecting module 1 cannot generate the detection feedback signal, i.e., pin 1 of U1 outputs a low level, and therefore the transistor Q01 cannot be turned on to turn off the analog leakage trigger signal. At this time, the trigger D01 is in a conducting state for a long time, and thus the analog leakage current signal also continues to flow. As the second capacitor C02 continues to charge, its upper plate potential continues to rise. When the upper plate potential of the second capacitor C02 reaches a preset value, the driving transistor Q1 and/or Q2 is turned on, so that current change is generated on the coil of the solenoid SOL to generate a magnetic field, and the switch SW1 and RESET are turned off, so that the power connection on the power supply line is disconnected. The failure of the leakage current detection module 1 includes, but is not limited to, the following cases: an open circuit or a short circuit occurs in the electronic components (for example, the leakage detection coil CT1, the resistor R1, and the like) in the leakage detection module 1, or the processor U1 is damaged, or the like. When this occurs, the processor U1 will not be able to output a high level. Since the first capacitor C01 supplies power to the processor U1 via the diode D02 while the trigger D01 is turned on, the processor U1 can detect the analog leakage current signal even if the analog leakage current signal is generated in the positive half cycle edge or the negative half cycle of the alternating current. This ensures the accuracy of fault signal generation module 24 in generating a self-test fault signal that is generated due to leakage current detection module 1 failing, rather than being misjudged due to processor U1 not being powered.

The operation of the self-test module 2 is explained below.

On the positive half cycle of the alternating current, the hot line (L) powers the processor U1, while charging the first capacitor C01 via the diode D11 and the first resistor R01. After a preset time, the upper plate potential of the first capacitor C01 reaches the trigger voltage of the trigger tube D01, which makes the trigger tube D01 conduct, thereby forming a current loop and generating an analog leakage current signal through the second resistor R02. Meanwhile, the first capacitor C01 supplies power to the processor U1 through the diode D02 to ensure that the processor U1 is supplied with additional operating power and is in an operating state.

The electric leakage detection module 1 works normally: the leakage detection coil CT1 detects the analog leakage current signal, and the induced voltage generated causes pin 1 of the processor U1 to output a high level. This high level turns on transistor Q01, which provides a discharge path for the first capacitor C01. The first capacitor C01 is discharged through the transistor Q01, and the upper plate potential thereof is lowered, so that the trigger voltage of the trigger transistor D01 cannot be reached. Therefore, the trigger D01 is turned off, and the current cannot flow through the trigger D01, and a current loop cannot be formed to generate the analog leakage current signal. At the same time, the first capacitor C01 cannot continue to supply power to the processor U1. The above process completes one cycle of self-checking. At the beginning of the next cycle, in the positive half cycle of the alternating current, the current continues to charge the first capacitor C01 until the upper plate potential of the first capacitor C01 reaches the trigger voltage of the trigger tube D01, and the above process is repeated.

The electric leakage detection module 1 is out of order: if the leakage detection module 1 loses the leakage protection capability due to the open circuit of the leakage detection coil CT1, the open circuit of the resistor R1, the damage of the processor U1, etc., the pin 1 of the processor U1 outputs a low level, and the transistor Q01 cannot be turned on. Since the transistor Q01 is in the off state, it is unable to provide a discharge path for the first capacitor C01, and therefore the upper plate potential of the first capacitor C01 makes the trigger D01 in the on state for a long time. In this case, the analog leakage current signal continues to flow through the second resistor R02. The current flowing through the third resistor R03 continuously charges the second capacitor C02, so that the upper plate potential of the second capacitor C02 continuously increases. When the upper plate potential of the second capacitor C02 reaches a preset value, the driving transistors Q1 and/or Q2 are/is turned on. The turning on of transistors Q1 and/or Q2 will cause the current in solenoid SOL to increase momentarily, thereby opening switch SW1 and RESET, i.e., breaking the power connection on the power supply line, which will no longer be usable by the user.

Fig. 3 shows a schematic view of an earth leakage protection device according to a second embodiment of the present disclosure.

In the embodiment of fig. 3, the main difference from fig. 2 is that two leakage inductance coils CT1 and CT2 are used in the leakage current detection module 1 of the leakage current protection device 300, so as to increase the leakage protection for the neutral wire. Accordingly, the RESET switches RESET are two sets. In addition, in the drive module 32 of the fault response module, two solenoids SOL1 and SOL2 are employed to provide redundant earth leakage protection when one of the solenoids is broken. Self-test module 2 of earth leakage protection device 300 also includes self-test compensation module 25 having diode D02 connected to pin 5 of processor U1. On the positive half cycle of the alternating current, the hot line (L) powers the processor U1, while charging the first capacitor C01 via the diode D11 and the first resistor R01. While the trigger D01 is turned on, the first capacitor C01 supplies power to the processor U1 via the diode D02. The other sub-modules of self-test module 2 will not be described in detail.

Fig. 4 shows a schematic view of an earth leakage protection device according to a third embodiment of the present disclosure.

In the embodiment of fig. 4, the main difference from fig. 2 lies in the composition and connection manner of the analog leakage trigger module 21 and the self-test compensation module 25. As shown in fig. 4, the diode D02 of the self-test compensation module 25 is directly connected to the first capacitor C01, not to the trigger D01. The leakage current triggering module 21 further comprises a further delay module. In this embodiment, the delay module includes a fourth resistor R04 and a third capacitor C03 connected in series, and is used for controlling the conduction of the trigger transistor D01, so as to control the interval time for generating the analog leakage trigger signal. By setting the resistance value of the fourth resistor R04 and the capacitance value of the third capacitor C03, the interval time for generating the analog leakage trigger signal can be adjusted. The hot line (L) is coupled to the first capacitor C01 and the third capacitor C03 through the diode D11, the first resistor R01 and the fourth resistor R04, respectively. During the positive half cycle of the alternating current, the live line (L) charges the first capacitor C01 through the first resistor R01, and simultaneously charges the third capacitor C03 through the fourth resistor R04. Once the diode D02 is turned on by the upper plate potential of the first capacitor C01, the first capacitor C01 supplies power to the processor U1 via the diode D02. In addition, when the upper plate potential of the third capacitor C03 reaches the trigger voltage of the trigger tube D01, the trigger tube D01 is turned on to generate an analog leakage trigger signal, and an analog leakage signal flowing through the leakage detection coil CT1 is generated through the second resistor R02. In this embodiment, since there is uncertainty in the time when the analog leakage current signal is generated, the first capacitor C01 is required to power the processor U1 during the entire cycle of the alternating current, thereby ensuring that U1 is in operation at any time. Therefore, the resistance value of the first resistor R01 and the capacitance value of the first capacitor C01 may be set according to the magnitude of the power supply voltage and the duration of the power supply time required by the processor U1. Thus, even if the analog leakage current signal is generated in the positive half cycle edge or the negative half cycle of the alternating current (the power supply line does not provide the working power supply for the U1), since the self-checking compensation module 25 provides the additional working power supply for the processor U1, the U1 is also in the working state, and the analog leakage current signal can be detected and the detection feedback signal can be generated without failure. This ensures the accuracy of fault signal generation module 24 in generating a self-test fault signal that is generated due to leakage current detection module 1 failing, rather than being misjudged due to processor U1 not being powered. The other sub-modules of self-test module 2 will not be described in detail.

Fig. 5 shows a schematic view of an earth leakage protection device according to a fourth embodiment of the present disclosure.

In the embodiment of fig. 5, the self-test module 2 of the earth leakage protection device 500 is the same as the embodiment of fig. 4, and other modules are the same as the embodiment of fig. 3, which will not be described again. In this embodiment, the self-test compensation module 25 powers the processor U1 throughout the entire cycle of alternating current. Thus, even if the analog leakage current signal is generated in the positive half cycle edge or the negative half cycle of the alternating current (the power supply line does not provide the working power supply for the U1), since the self-checking compensation module 25 provides the additional working power supply for the processor U1, the U1 is also in the working state, and the analog leakage current signal can be detected and the detection feedback signal can be generated without failure.

In the above embodiments, the self-test compensation module continuously provides the leakage current detection module with additional operating power while generating the analog leakage trigger signal or for a long time. Therefore, when the analog leakage trigger signal and the analog leakage signal are generated at any time, the leakage current detection module is in a working state due to the working power supply, and can correctly detect the analog leakage signal and generate a detection feedback signal under the condition of no fault. Therefore, misjudgment possibly caused by the fact that the leakage current detection module is not powered in the positive half cycle edge or the negative half cycle of the alternating current is avoided, and detection accuracy of the self-detection module is guaranteed.

Although the transistor is exemplified in the above embodiments, it is understood that the transistor may be any other type of semiconductor element, such as any switching element having a voltage threshold as a trigger, for example, a photocoupler.

The present disclosure also provides an electrical connection apparatus, comprising: a housing; and an earth leakage protection device according to any of the above embodiments, the earth leakage protection device being housed in the housing.

A third aspect of the present disclosure proposes an electrical appliance, comprising: a load device; an electrical connection device coupled between the power supply line and the load device for supplying power to the load device, the electrical connection device comprising an earth leakage protection device according to any of the embodiments described above.

Thus, while the present invention has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the invention, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the invention.

Claims (12)

1. An earth leakage protection device, characterized in that it comprises:

a leakage current detection module configured to detect a leakage current signal on a power supply line that supplies power to the leakage current detection module in a half cycle of an alternating current, and to generate a detection feedback signal when the leakage current signal is detected; and

a self-test module configured to detect whether the leakage current detection module malfunctions based on the detection feedback signal, the self-test module comprising:

an analog leakage current generation module configured to generate an analog leakage current signal to simulate the leakage current signal;

a fault signal generation module configured to generate a self-test fault signal when the leakage current detection module fails; and

the self-checking compensation module is configured to provide an additional working power supply for the leakage current detection module, so as to ensure that the leakage current detection module is in a working state when the analog leakage current signal is generated.

2. A residual current device according to claim 1, characterized in that said self-test compensation module comprises:

an energy storage module configured to store electrical energy obtained from the power supply line; and

a power coupling element configured to couple the energy storage module to a power circuit of the leakage current detection module to provide the electrical energy to the leakage current detection module.

3. A residual current protection device according to claim 2, characterized in that,

the energy storage module comprises a first resistor and a first capacitor which are connected in series, the power supply line charges the first capacitor through the first resistor, and the first capacitor is used for providing the electric energy for the leakage current detection module through the power supply coupling element.

4. A residual current device as claimed in claim 2, characterized in that said power coupling element is selected from one or more of the following: a unidirectional conducting element, a controllable semiconductor element and a resistor.

5. The earth leakage protection device of claim 3, wherein the self-test module further comprises:

an analog leakage trigger module configured to generate an analog leakage trigger signal; and

a trigger signal shutdown module configured to shut down the analog leakage trigger signal under the action of the detection feedback signal, wherein,

the analog leakage current generation module generates the analog leakage current signal through triggering of the analog leakage trigger signal, and the fault signal generation module is coupled to the analog leakage trigger module.

6. A residual current protection device according to claim 5, characterized in that,

the first capacitor responds to the generation and the closing of the analog leakage trigger signal, and provides the electric energy to the leakage current detection module or stops providing the electric energy.

7. A residual current protection device according to claim 6,

the analog leakage trigger module comprises a trigger tube, one end of the trigger tube is coupled between the first resistor and the first capacitor, the other end of the trigger tube is coupled to the power supply coupling element, and the trigger tube generates the analog leakage trigger signal when the trigger tube is switched on.

8. A residual current protection device according to claim 3,

the first capacitor supplies the electric energy to the leakage current detection module in the whole period of the alternating current.

9. The earth leakage protection device of claim 5, wherein the analog leakage trigger module, the analog leakage current generation module, the trigger signal shutdown module, the fault signal generation module, and the self-checking compensation module are all composed of discrete electronic components.

10. A residual current device as claimed in claim 1, characterized in that said residual current device further comprises:

a fault response module configured to send out a fault indication message and/or to disconnect the electrical power connection on the power supply line under the effect of the self-test fault signal.

11. An electrical connection apparatus, comprising:

a housing; and

the earth leakage protection device according to any of claims 1-10, which is accommodated in the housing.

12. An electrical consumer, characterized in that it comprises:

a load device;

an electrical connection device coupled between a power supply line and the load device for supplying power to the load device, wherein the electrical connection device comprises a residual current device according to any one of claims 1-10.

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