TWI802110B - Balance device to reduce leakage current - Google Patents

Abstract

A balance device for reducing leakage current, comprising: a balance coil module set between a preset load and a power supply terminal, and a control module; the balance coil module has a first coil, a second coil, and a third coil , the first coil and the second coil are respectively connected to the two ends of the load, the third coil is connected to the control module, and the first coil can receive a supply current from the power supply end to the load direction to generate a Forward magnetic field, the second coil can receive a return current from the load to the direction of the power supply to generate a reverse magnetic field, the control module can detect and calculate the difference between the supply current and the return current, and control The third coil generates a compensating magnetic field that can bridge the gap between the forward magnetic field and the reverse magnetic field, so as to keep the magnetic field and current inside the balance coil module in a balanced state, so as to reduce the leakage current and maintain the basic power supply .

Description

Balance device to reduce leakage current

The present invention relates to a balance device for reducing leakage current, especially a device that can effectively reduce leakage (touch) current and maintain power supply to electrical equipment when electrical equipment is flooded or human body gets an electric shock, so as to ensure the safety of personnel and maintain the basic operation of electrical equipment The balance device.

With the gradual popularization of various electrical appliances and electronic devices, people's demand for various electricity consumption is also increasing. In most (household or industrial) electricity consumption environments, the mains power is a stable and convenient source of electricity, and the current The mains power supply is transmitted by the power plant through high-voltage wires, and then transformed to various fixed voltages for different end consumers to connect to electrical appliances and electronic devices through wires according to their needs; however, in general living environments and users During the electrical process, many natural disasters or human errors are often encountered, resulting in various leakage (shock) situations.

As we all know, when electrical equipment is immersed in water, leakage current may be generated from the power connection part (the part where the plug of the electrical equipment is connected to the power socket or the exposed part of the wire leading into the power supply) to the earth, or when the human body touches the exposed power connection part , will generate current through the human body to the earth from the power connection part. This kind of leakage current will often cause human injury to the user and damage to related electrical equipment. Therefore, most current transmission and distribution or power supply equipment will be equipped with a leakage circuit breaker switch. Immediately cut off the connection with the power supply when a leakage occurs in the power supply line or electrical equipment or electronic device, so as to protect the safety of personnel and electrical equipment; however, the above-mentioned leakage circuit breaker can only cut off the power supply after the leakage occurs. does not have The function of reducing or eliminating leakage current. Moreover, many electrical equipment (such as: life-supporting medical equipment or computer equipment for storing data) do not allow power-off at any time. Any unexpected power-off will cause life and economic loss. serious loss.

Therefore, a safety device for preventing electrical accidents is provided in Korean Registered Patent No. 10-2270589. According to the content disclosed in the patent, in the case of electrical circuit immersion, the safety device can prevent electric shock accidents and also It can continuously supply the minimum required power to the electrical equipment, so that the electrical equipment can continue to operate normally.

In addition, Korean registered patent No. 10-1705090 discloses structures with grounding disconnection sensing devices and power protection devices; device and the leakage and electric shock protection method using the leakage prevention device, although it is recorded in its instruction manual that "when an electric shock accident occurs, after a balance transformer can offset the magnetic field generated by the leakage current, the intensity of the leakage current can be reduced to To the extent that it does not cause danger to the human body”, however, in its patent specification, there is only a simple diagram of the relationship between load and series connection, so ordinary technical personnel in this field cannot directly implement the relevant technical means from the content disclosed in the patent, let alone I don't know whether the content of the patent can actually work. Even if it can operate normally according to the content of the patent, it is impossible to properly operate because the time point of the normal operation falls after the electrical connection part has been flooded or the human body has been electrocuted. Prevent electric shock accidents.

Furthermore, the magnitude of the above-mentioned leakage current varies according to the state of the line formed between the power connection part and the earth (including the human body, etc.). Both the current flowing on the coil and the current flowing in the reverse direction (from the load back to the power supply) coil will change. As a result, the magnitude of the magnetic field generated on the coil flowing forward current and the coil flowing reverse current will be different from each other. As a result, the balance between currents cannot be reliably maintained. Furthermore, since the electric current flowing to the earth through the exposed contact part increases, it is impossible to properly deal with electric shock accidents.

In addition, Korean Registered Patent No. 10-0749837 discloses a balance transformer, which can adjust the current flowing on loads connected in parallel to a uniform state. Theoretically speaking, the patent mentions a method of "maintaining the balance of the flowing current through reversely connected coils", but this method is only a theory that allows the current flowing on the parallel load to maintain a balanced state. ; In other words, this theory has nothing to do with preventing electric shock accidents caused by the current flowing from the exposed contact part to the earth.

Due to the above-mentioned leakage (shock) process, in addition to forming a variety of different current paths between the power connection part, the load and the earth, according to various conditions (such as: flooding conditions, conditions between the power connection part and the earth, overall circuit grounding conditions, etc.), the resistance value generated on the current path (hereinafter referred to as "leakage load") will also change; therefore, how to reduce the leakage (touch) ) current, and can maintain continuous power supply to related electrical equipment to avoid failure, which is an urgent issue for relevant industry players.

In view of the above-mentioned shortcomings in the actual application of conventional devices for reducing electric leakage or preventing electric shocks, the inventors have studied and improved ways to address these shortcomings, and finally have the present invention.

The main purpose of the present invention is to provide a balance device for reducing leakage current, which includes: a balance coil module set between a preset load and a power supply terminal, and a control module; the balance coil module has a first coil , the second coil, and the third coil; wherein the first coil and the second coil are respectively connected in series with the two ends of the load, the third coil is connected to the control module, and the first coil can be subjected to A supply current flowing from the power supply terminal to the load direction passes through to generate a positive magnetic field. The second coil can receive a return current flowing from the load to the power supply terminal to generate a reverse magnetic field. The control module can Detect and calculate the difference between the supply current and the return current, and control the third coil to generate a compensation magnetic field that can compensate the difference between the supply current and the return current, so as to maintain the magnetic field inside the balance coil module In a balanced state, the effect of reducing the above-mentioned leakage current and truly protecting human life is achieved.

Another object of the present invention is to provide a balance device that reduces leakage current. Since the third coil of the balance coil module can cooperate with the first coil or the second coil to form an interaction as required, the balance coil module can The magnetic field inside the group is close to balance, and then the strength of the above-mentioned leakage current is reduced to the lowest state, so as to achieve the effect of minimizing the risk of leakage or electric shock.

Another object of the present invention is to provide a balance device for reducing leakage current, which can provide the most basic power supply to the load at the same time during the interaction of the coils in the balance coil module to ensure that the load can maintain Basic normal operation, thereby avoiding life safety or economic losses caused by unexpected power outages.

In order to achieve the above purpose and effect, the technical means adopted by the present invention include: a balance coil module for reducing leakage current, including: a balance coil module arranged between a preset load and a power supply terminal; the balance coil module The group has a first coil, a second coil, and a third coil; wherein the first coil and the second coil are respectively connected to the two ends of the load, and the first coil can flow the supply current flowing from the power supply end to the load direction, To generate a positive magnetic field, the second coil can flow a return current flowing from the load to the power supply end, thereby generating a reverse magnetic field, and the third coil can be supplied with a current to generate a positive magnetic field that can compensate The compensating magnetic field for the gap with the opposing magnetic field.

The technical means adopted by the present invention also includes: a balance device for reducing leakage current formed by the above-mentioned balance coil module, wherein the first coil, the second coil of the balance coil module The coils are respectively connected to the two ends of the load, and the third coil is connected to a control module. The first coil can receive a supply current flowing from the power supply end to the load direction to generate a positive magnetic field. The second coil can receive a return current flowing from the load to the power terminal to generate a reverse magnetic field. The control module can detect and calculate the difference between the supply current and the return current, and A current is controlled to pass through the third coil, so as to generate a compensating magnetic field that can make up the difference between the forward magnetic field and the reverse magnetic field.

According to the above structure, the control module has a supply current sensing part and a return current sensing part, which are respectively arranged at the two ends of the load; the control module can respectively sense the current passing through the supply current sensing part The magnitude of the supply current and the magnitude of the return current passing through the return current sensing part are calculated to control the current passing through the third coil after calculating the magnitude difference between the supply current and the return current.

According to the above structure, the control module can output a control current to the third coil, so as to make the third coil generate the compensation magnetic field.

According to the above structure, the control module adjusts the direction control of the control current to be consistent with the direction of the supply current passing through the first coil.

According to the above structure, the control module adjusts the direction of the control current to be consistent with the direction of the return current passing through the second coil.

According to the above structure, wherein the third coils are respectively connected to the power supply terminals, the control module includes a switch group arranged between the third coil and the power supply terminals, when the control module operates the switch group Conducting the third coil and the power supply terminal can make the third coil energized to generate the compensation magnetic field.

According to the above structure, the number of turns of the first coil: the number of turns of the second coil: the number of turns of the third coil = 1:1:2.

According to the above structure, wherein the third coil has an intermediate tap, the third coil can be equally divided into two coils with the same number of turns, and the switch group includes a first switch and a second switch, the first switch The switch relationship is arranged between one end of the third coil and the power supply end, and the second switching switch relationship is arranged between the middle tap and the power supply end.

According to the above structure, the number of turns of the first coil: the number of turns of the second coil: the number of turns of the third coil = 1:1:1.

According to the above structure, the switching switch group further includes a power-off switch, and the power-off switch is arranged between the balance coil module and the power supply terminal.

In order to obtain a more specific understanding of the above-mentioned purpose, effect and characteristics of the present invention, the following drawings are hereby described as follows:

10: Balance coil module

20: Control module

21: Supply current sensing unit

22: Return current sensing part

23: switch group

231: The first toggle switch

232: Second toggle switch

24:Power off switch

25: socket

100: Balance device to reduce leakage current

200: load

300: Leakage load circuit

DI: the distance between the power terminal and the electric shock position

DO: the distance between the ground terminal and the electric shock location

Ls, Lt, Lp: leakage inductance

Lm: magnetizing inductance

IB: leakage current

IC: Control Current

IL: load current

Iin: supply current

Iout: return current

N1: the first coil

N2: second coil

N3: the third coil

N11: first end

N12: second end

N21: third end

N22: the fourth terminal

N31: Center tap

NS, N: Ground terminal

PS, R, S, T: Power terminals

R1, R2, R3, Rbody: resistance

Rs, Rt, Rp: internal resistance

S: electric shock position

VC: control voltage

Vin: power terminal

Fig. 1 is a complete circuit block diagram of the first embodiment of the present invention.

Figure 2 is an analog equivalent circuit diagram of the circuit block in Figure 1 at specific component values.

Fig. 3 is a comparison diagram of load current and leakage current when no balance coil module is installed in the circuit structure of Fig. 2 and the leakage load circuit is connected to the load (abnormal state).

Fig. 4 is a comparison diagram of load current and leakage current when the control module does not drive the balance coil module in the circuit structure of Fig. 2 and the leakage load circuit is connected to the load (abnormal state).

Figure 5 is a comparison diagram of the load current and leakage current before and after the control module drives the balance coil module in the circuit structure of Figure 2.

Fig. 6 is an embodiment diagram of the first embodiment of the present invention applied between a three-phase four-wire power supply and a load.

Fig. 7 is an embodiment diagram of the first embodiment of the present invention applied between a three-phase three-wire power supply and a load.

Fig. 8 is a schematic diagram of an application situation of the first embodiment of the present invention.

Fig. 9 is a circuit block diagram of the second embodiment of the present invention.

Fig. 10 is a circuit block diagram of the third embodiment of the present invention.

Fig. 11 is a circuit block diagram of the fourth embodiment of the present invention.

Please refer to Figures 1 to 2, it can be seen that the main structure of the balance device 100 for reducing leakage current according to the first embodiment of the present invention includes: a balance coil module 10 and a control module 20; wherein the balance coil module 10 It is arranged between a load 200 and a power supply terminal Vin. The balance coil module 10 has a first coil N1, a second coil N2, and a third coil N3. One end of the first coil N1 has a first terminal N11 connected to The power supply terminal PS of the power supply terminal Vin, the other end of the first coil N1 has a second terminal N12 connected to one end of the load 200, and one end of the second coil N2 has a fourth terminal N22 connected to the power supply terminal The ground terminal NS of Vin, the other end of the second coil N2 has a third end N21, which is connected to the other end of the load 200, so that the first coil N1 and the second coil N2 are respectively connected in series to the two ends of the load 200 combination state.

The third coil N3 is connected to the control module 20, and the control module 20 has a supply current sensing part 21 and a return current sensing part 22, which are respectively arranged at two ends of the load 200; the control module 20 Can respectively sense the direction from the power supply terminal Vin to the load 200 passing through the supply current sensing part 21 The magnitude of the flowing supply current Iin, and the magnitude of the return current Iout flowing from the load 200 to the power terminal Vin through the return current sensing part 22, and calculate the magnitude difference between the supply current Iin and the return current Iout, and then output a control The current IC flows to the third coil N3 to generate a compensating magnetic field, so as to drive the magnetic field generated by the supply current Iin and return current Iout respectively in the balance coil module 10 to form a balance.

In the above-mentioned structure, the control module 20 is a circuit device capable of performing an AC-AC conversion function, and it starts to operate after being powered on. Its specific structure and operation method belong to a common technical content in the field, so A detailed description of the control module 20 is omitted here.

In actual application, when the human body touches the exposed conductive parts of the load 200 (i.e. electrical appliances, electronic products), or when the conductive parts of the load 200 are immersed in water, various leakage circuits will be formed between the conductive parts and the earth, and each A parallel circuit is formed between the leakage circuit system and the load 200; in order to facilitate understanding, a leakage load circuit 300 is connected in parallel to the two ends of the load 200 in Figure 1, so as to simulate the current flow of the load 200 in abnormal states such as leakage or electric shock state.

In a feasible embodiment, the leakage load circuit 300 has a resistor R3 connected in parallel to the two terminals of the load 200, and the two terminals of the resistor R3 are respectively connected to one end of a resistor Rbody via a resistor R1 and a resistor R2, and The other end of the resistor Rbody is grounded.

The simulation condition is PSIM 64-bit Version 9.0, AC 220V: peak voltage 311V (=RMS 220V), the power supplied by the control module 20 to the third coil N3 is 60Hz AC 44V: peak voltage 62.2V (=RMS 44V); and the load 200 is composed of a 10mH inductance and a 100Ω resistor in series, and the resistance R1 of the leakage load circuit 300 is 80Ω, the resistance R2 is 20Ω, the resistance R3 is 20Ω, and the resistance Rbody is 500Ω, the above-mentioned first The analog equivalent circuit of the figure is shown in Figure 2.

Please refer to Figures 3 to 5, in general, the load 200 that does not have the balance device 100 for reducing leakage current similar to the present invention is in operation (that is, in Figure 2, the structure of the balance device 100 for reducing leakage current is lacking. ) when an abnormal state such as leakage or electric shock occurs, the magnitude of the supply current Iin is the sum of the load current IL passing through the load 200, the leakage current IB passing through the resistor Rbody, and the current flowing through the resistors R1, R2, and R3 , and the size of the return current Iout is the supply current Iin minus the leakage current IB flowing in the direction of the resistance Rbody; at this time, the load current IL passing through the load 200 and the The magnitude and waveform of the simulated leakage current IB passing through the resistor Rbody are shown in FIG. 3 , wherein the load current IL is approximately 3.1A, and the leakage current IB is approximately 0.125A.

In the structure of the above-mentioned Fig. 2, the coil turns of the first coil N1, the second coil N2, and the third coil N3 of the balance coil module 10 are each set to 100 turns, and the internal resistance Rs of the first coil N1, The internal resistance Rt of the second coil N2 and the internal resistance Rp of the third coil N3 are both set to 0.1Ω, and the leakage inductance Ls of the first coil N1, the leakage inductance Lt of the second coil N2 and the leakage inductance of the third coil N3 Both Lp are 0.0001H; at this time, the magnetizing inductance Lm is 0.2H.

Therefore, the parameters of the balance coil module 10 are listed in the following table:

Similarly, in the structure of the above-mentioned Fig. 2, when abnormal conditions such as electric leakage or electric shock occur, if the balance device 100 for reducing leakage current does not operate normally, the load current IL passing through the load 200 and passing through The magnitude and waveform of the simulated leakage current IB of the resistor Rbody are as shown in Figure 4; as shown in Figure 3 and Figure 4 above, no matter the balance coil module 10 is not set, or the balance coil module When the group 10 is not in operation, the magnitudes of the load current IL passing through the load 200 and the simulated leakage current IB will not change much.

However, in the structure of the above-mentioned first embodiment of the present invention, when abnormal conditions such as electric leakage or electric shock occur, if the balance device 100 for reducing leakage current operates normally, the control module 20 can supply current through the sensing part 21 senses the size of the supply current Iin, and senses the size of the return current Iout through the return current sensing part 22, and calculates the magnitude difference between the supply current Iin and the return current Iout; wherein, if the supply current Iin is greater than The return current Iout, the control current IC output by the control module 20 is in the same direction as the return current Iout flowing in the second coil N2, so that the third coil N3 generates a compensation in the same direction as the second coil N2 magnetic field, so as to balance the positive magnetic field generated by the supply current Iin passing through the first coil N1; and in some special cases, if the supply current Iin is smaller than the return current Iout, the output control of the control module 20 The current IC is in the same direction as the supply current Iin flowing in the first coil N2, so that the third coil N3 generates a compensating magnetic field in the same direction as the first coil N1, so as to balance the return current Iout through the second coil N2 The generated reverse magnetic field; therefore, using the above method, the magnetic field generated by the supply current Iin and the return current Iout respectively in the balance coil module 10 can be balanced.

At this time, the magnitude and waveform of the load current IL passing through the load 200 and the simulated leakage current IB passing through the resistor Rbody are as shown in Fig. 5, and it can be clearly seen from the content disclosed in Fig. 5 The load current IL passing through the load 200 is approximately 3.1A, which is the same as that shown in Figures 3 and 4 above. The values are the same, which means that in the event of abnormal conditions such as electric leakage or electric shock, the load 200 can still be provided with a basically normal power supply, but the simulated leakage current IB is reduced from approximately 0.125A to approximately 0.003A. Significant reduction in the magnitude of current IB indicates that leakage and contact currents can be effectively reduced.

Please refer to Figures 6 and 7. It can be seen that the structure of the above-mentioned first embodiment of the present invention, if it is applied to a three-phase four-wire power supply, each balancing device 100 for reducing leakage current is respectively arranged on the three-phase Between the power supply terminals R, S, T of each power supply and the ground terminal N (as shown in Figure 6); and if it is applied to a three-phase three-wire power supply, each balancing device 100 for reducing leakage current is respectively It is arranged between the power terminals R, S, and T of each power supply of the three-phase power supply (as shown in Fig. 7).

Please refer to FIG. 8, it can be seen that the above-mentioned balance device 100 for reducing leakage current of the present invention is actually used, and a power supply terminal Vin is connected to a socket 25 or other devices that can be connected to a load 200 through the balance device 100 for reducing leakage current. In the environment where the load 200 obtains power through the socket 25 (i.e., the more common electric leakage environment); when the socket 25 is immersed in water, a leakage environment is caused, and an electric shock occurs in the leakage environment Position S, assuming that the distance between the power contact in the socket 25 (that is, the contact that is connected to the power terminal PS) and the electric shock position S is DI, and the ground contact in the socket 25 (that is, that that is connected to the ground The distance between the contact point of terminal NS) and the electric shock position S is DO, then under the condition that the distance between the power contact and the ground contact in the socket 25 is close enough, the distance between the power contact and the electric shock position S The distance DI can be regarded as equal to the distance DO between the ground contact and the electric shock location S.

Please refer to Fig. 9, because in the leakage environment in Fig. 8 above, the control module 20 in the balance device 100 for reducing leakage current outputs the control voltage VC to the third coil N3 to minimize the leakage current, It is determined by the ratio of the electric shock position S to the power contact in the socket 25 and the ground contact through the underwater path (ie, the resistance R1 and the resistance R2 in the leakage load circuit 300 ). Determine; according to the conclusion that the distance DI between the power contact and the electric shock position S is equal to the distance DO between the ground contact and the electric shock position S, it can be known that the distance DI and the distance between the power contact and the electric shock position S The resistance generated by the two paths such as the distance DO between the ground contact and the electric shock position S (ie, the resistance R1 and the resistance R2 in the leakage load circuit 300 ) is almost the same.

Under the above circumstances, if the number of turns of the first coil N1 in the balance coil module 10: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:1, then the control voltage VC=power supply The voltage of the terminal Vin/2; and if the number of turns of the first coil N1 in the balance coil module 10: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:2, then the control voltage VC=Vin voltage at the power supply terminal.

At this time, in the second embodiment of the present invention, if the number of turns of the first coil N1 in the balance coil module 10: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:2 The structure of the structure is that the two ends of the third coil N3 are respectively connected to the power supply terminal Vin, and the control module 20 is further provided with a switch group 23 between the third coil N3 and the power supply terminal Vin, and the other parts of the circuit The structure is the same as that of the aforementioned first embodiment; thereby, when the control module 20 senses and calculates the magnitude difference between the supply current Iin and the return current Iout, it can directly drive the switch group 23 to turn on the third coil N3 Connecting to the power terminal Vin, the third coil N3 is energized to generate the compensating magnetic field, so as to reduce the magnitude of the leakage current IB.

Because in this structure, the control module 20 does not need to perform complex calculations and operations (convert the voltage of the power supply terminal Vin, and adjust the size of the control current IC), so the structure of the control module 20 can be effectively simplified. To reduce costs, improve economic efficiency and other effects.

Please refer to Figure 10, it can be seen that in the application environment in Figure 8 above, if the location where the leakage occurs is that the power terminal PS connected to the power terminal Vin is directly grounded (connected to the ground), then the The sum of resistance R1, resistance R2 and resistance R3 combined is 0; at this time, if the balance The number of turns of the first coil N1 in the coil module 10 : the number of turns of the second coil N2 : the number of turns of the third coil N3 = 1:1:1, then the control voltage VC=the voltage of the power supply terminal Vin is optimal.

Therefore, in the third embodiment of the present invention, if the number of turns of the first coil N1 in the balanced coil module 10: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:1 To form a structure, the two ends of the third coil N3 are respectively connected to the power supply terminal Vin, and the control module 20 is further provided with a switching switch group 23 between the third coil N3 and the power supply terminal Vin, and the other parts of the circuit structure It is the same as the aforementioned first embodiment; thereby, when the control module 20 senses and calculates that the supply current Iin and the return current Iout have a magnitude difference, it can directly drive the switch group 23 to turn on the third coil N3 and the return current Iout. The power terminal Vin energizes the third coil N3 to generate the compensating magnetic field, so as to reduce the magnitude of the leakage current IB.

Please refer to Fig. 11, it can be seen that the structure of the balance device 100 for reducing leakage current in the fourth embodiment of the present invention includes: a balance coil module 10 and a control module 20; wherein the balance coil module 10 has The first coil N1, the second coil N2, the third coil N3, the number of turns of the first coil N1: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:2, the number of turns of the first coil N1 and the second coil N2 are respectively connected in series with two ends of a load 200. The third coil N3 has a center tap N31, which can divide the third coil N3 into two coils with the same number of turns.

The control module 20 can operate and control a switching switch group 23 and a power-off switch 24 respectively. The switching switch group 23 includes a first switching switch 231 and a second switching switch 232. The first switching switch 231 is arranged on the second switching switch 231. Between one end of the three-coil N3 and the power supply terminal Vin, the second switch 232 is set between the center tap N31 and the power supply terminal Vin, and the power-off switch 24 is set between the balance coil module 10 and the power supply terminal Vin. Between the power supply terminals Vin; in addition, the connection relationship between the balance coil module 10, the control module 20 and other related components is the same as that of the second and third embodiments described above, and will not be repeated here.

In actual application, after the control module 20 senses and calculates the magnitude difference between the supply current Iin and the return current Iout; the control module 20 can first drive the first switch 231 to turn on the complete third coil N3 With the power supply terminal Vin, the number of turns of the first coil N1: the number of turns of the second coil N2: the number of turns of the third coil N3=1:1:2, the balance device 100 for reducing leakage current has the same characteristics as the aforementioned The same structural features of the second embodiment, and can produce the same effect as the second embodiment; if the above actions can not effectively reduce the magnitude of the leakage current IB, then the control module 20 will drive the second switch 232 to be turned on again The center tap N31 and the power supply terminal Vin, at this time, the number of turns of the first coil N1: the number of turns of the second coil N2: the number of turns of the third coil N3 = 1:1:1, the balance of reducing the leakage current The device 100 has the same structural features as the aforementioned third embodiment, and can produce the same effect as the third embodiment; and if the above operations still cannot reduce the size of the leakage current IB below the expected range, then the The control module 20 drives the cut-off switch 24 to cut off the connection between the balance coil module 10 and the power terminal Vin, so as to prevent possible electric shock accidents.

Based on the above, the balance device for reducing leakage current of the present invention can effectively reduce the leakage (touch) current when the electrical equipment is immersed in water or the human body gets an electric shock, and maintain the effect of basically normal power supply to the electrical equipment. It is a novel device. For innovative and progressive inventions, please apply for an invention patent in accordance with the law; however, the content of the above description is only a description of the preferred embodiment of the present invention, for example, any changes, modifications, changes or other extensions based on the technical means and scope of the present invention Effective replacements should also fall within the scope of the patent application of the present invention.

10: Balance coil module 20: Control Module 21: Supply current sensing unit 22: Return current sensing part 100: Balance device to reduce leakage current 200: load 300: Leaky load circuit IB: leakage current IC: Control current IL: load current Iin: supply current Iout: return current N1: first coil N2: second coil N3: third coil N11: first end N12: second end N21: third end N22: Fourth terminal NS: Ground terminal PS: power terminal R1, R2, R3, Rbody: Resistors Vin: power terminal

Claims (9)

A balance device for reducing leakage current, comprising: a balance coil module (10) arranged between a preset load (200) and a power supply terminal (Vin); the balance coil module (10) has a first coil (N1 ), the second coil (N2), the third coil (N3); wherein the first coil (N1) and the second coil (N2) of the balance coil module (10) are respectively connected to two of the load (200) Terminal, and the third coil (N3) is connected to a control module (20), the control module (20) has a supply current sensing part (21) and a return current sensing part (22), respectively set At the two ends of the load (200); the first coil (N1) can receive a supply current (Iin) flowing in the direction of the load (200) from the power supply terminal (Vin), and generate a positive magnetic field, The second coil (N2) can receive a return current (Iout) flowing from the load (200) to the power supply terminal (Vin), and generate a reverse magnetic field, and the control module (20) can be respectively Sensing the magnitude of the supply current (Iin) passing through the supply current sensing part (21) and the magnitude of the return current (Iout) passing through the return current sensing part (22), and then calculating the supply current ( Iin) and the return current (Iout), and control a current to pass through the third coil (N3), so as to generate a compensation magnetic field that can make up the gap between the forward magnetic field and the reverse magnetic field. The balance device for reducing leakage current as described in claim 1, wherein the control module (20) can output a control current (IC) to the third coil (N3), so that the third coil (N3) generates The compensating magnetic field. The balance device for reducing leakage current as described in claim 2, wherein the control module (20) adjusts the direction control of the control current (IC) to be consistent with the direction of the supply current passing through the first coil (N1) state. The balance device for reducing leakage current as described in claim 2, wherein the control module (20) adjusts the direction control of the control current (IC) to be consistent with the return current direction passing through the second coil (N2) state. The balance device for reducing leakage current as described in claim 1, wherein the third coil (N3) is connected to the power supply terminal (Vin) respectively, and the control module (20) includes a device located on the third coil (N3) ) and the switch group (23) between the power terminal (Vin), when the control module (20) operates the switch group (23) to conduct the third coil (N3) and the power terminal (Vin), The compensation magnetic field can be generated by energizing the third coil (N3). The balance device for reducing leakage current as described in Claim 5, wherein the number of turns of the first coil (N1): the number of turns of the second coil (N2): the number of turns of the third coil (N3)=1: 1:2. The balance device for reducing leakage current as described in claim 6, wherein the third coil (N3) has a center tap (N31), which can divide the third coil (N3) into two coils with the same number of turns, and The changeover switch group (23) includes a first changeover switch (231) and a second changeover switch (232), and the first changeover switch (231) is arranged at one end of the third coil (N3) and the power supply end (Vin) Between, the second switching switch (232) is arranged between the middle tap (N31) and the power terminal (Vin). The balance device for reducing leakage current as described in Claim 5, wherein the number of turns of the first coil (N1): the number of turns of the second coil (N2): the number of turns of the third coil (N3)=1:1:1 . The balance device for reducing leakage current as described in claim 5 or 6 or 7 or 8, wherein the switching switch group (23) further includes a power-off switch (24), and the power-off switch (24) is set on the balance Between the coil module (10) and the power supply terminal (Vin).

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