WO2020103554A1

WO2020103554A1 - Leakage detection integrated circuit chip, leakage detection protection circuit and electrical appliance

Info

Publication number: WO2020103554A1
Application number: PCT/CN2019/106603
Authority: WO
Inventors: 高东兴
Original assignee: 深圳市晶扬电子有限公司
Priority date: 2018-11-23
Filing date: 2019-09-19
Publication date: 2020-05-28

Abstract

Disclosed in the present application are a leakage detection integrated circuit chip, a leakage detection protection circuit, and an electrical appliance, the chip comprising a signal conversion circuit, digital filter, detection control circuit, and silicon-controlled rectifier driving control circuit that are successively connected to a current transformer; the signal conversion circuit amplifies a received analog current detection signal outputted by the current transformer, and converts same into a digital current detection signal and then outputs same; the digital filter filters the digital current detection signal; the silicon-controlled rectifier driving control circuit is used for driving silicon-controlled conduction when a control signal that is outputted by the detection control circuit and that represents the current detection signal being a leakage current signal is received so as to control a trip to perform a tripping action. The present application solves the problem in which the anti-jamming capabilities of a leakage detection protection chip is weak, such that a false protection action is easily triggered.

Description

Leakage detection integrated circuit chip, leakage detection protection circuit and electrical equipment The

This application requires November 23, 2018, the application numbers are 201811412663.9, 201821952560.7 and 201821968028.4. The priority of the Chinese patent application with the name "leakage detection integrated circuit chip, leakage detection protection circuit and electrical equipment" is here. Introduced as a reference.

Technical field

This application relates to the technical field of electronic circuits, in particular to a leakage detection integrated circuit chip, a leakage detection protection circuit and electrical equipment.

Background technique

With the popularization and application of household appliances, the standards for human body electric shock protection are becoming stricter. At present, the minimum protection operating current defined by the Underwriters Laboratories (UL) leakage protection standard UL943 is only 5 mA, requiring a leakage current of 4 mA There is no erroneous operation in the following. At the same time, when the leakage current is greater than or equal to 6mA, protective action must be performed.

At present, due to the increasingly strict standards of human body electric shock protection, the leakage detection protection chip has higher requirements on the product parameters of peripheral devices. The current standard requires accurate judgment of the leakage current. The current leakage current detection circuit is susceptible to external interference signals when detecting the leakage current, resulting in the occurrence of erroneous protection actions.

In order to solve the problem of anti-interference, in some existing embodiments, for example, the leakage protection detection chip RV4010 / RV4141 / RV4145 / RV4146 / RV4149 series of American Fairchild Corporation adopts a bipolar integrated circuit process, using The low-noise characteristic of the bipolar process is used to make a high-performance operational amplifier to amplify the leakage signal, and then use an analog comparator to compare and judge the amplitude. In the subsequent series of chips, delay control logic is added to improve the anti-interference ability. From the evolution of this series of chips, it can be seen that due to the stricter standards of the new generation of human body electric shock protection standards, it is more difficult to follow the previous principles and methods of circuit design, and the chip has paid a large price in terms of area and cost.

In addition, VG54123A produced by Fudan Microelectronics is a representative of another type of chip. The chip continues the early principles and structure of the 54123 series of chips, but uses a CMOS process for circuit implementation. Due to the cost advantages of the CMOS semiconductor process, the cost control of the chip is excellent. However, because the chip scheme still follows the previous circuit principle and detection method, it has poor performance in terms of anti-interference ability. In addition, the large noise of the CMOS semiconductor process itself deteriorates the anti-interference ability of the series of chips.

The Chinese patent (patent number CN105186448A) gives a circuit principle that enhances the interference capability of the 54123 leakage protection detection chip. By using a filter network formed by additional resistance and capacitance, the anti-interference ability of the leakage detection protection chip can be improved to a certain extent. However, additional resistance and capacitor devices will increase the cost and production process, and due to cost and design, it is impossible to achieve a high-order filter network, so there are certain restrictions on the filtering and suppression of interference signals.

Another Chinese patent (CN201781262U) gives a digital method to achieve leakage protection. In the method of this patent, a complete circuit for leakage detection is formed by a leakage sampling loop, an analog-to-digital (A / D) converter, and an MCU (microcontroller). A similar method is also mentioned in the US patent (US7193827B2), which uses a current transformer, preamplifier circuit, analog-to-digital converter, and microprocessor to form a complete circuit for leakage detection. Similar circuit structures and methods are also mentioned in the US patent (US20090108967A1) and the US patent (US9048656B2). The above method uses an analog-to-digital converter and a microcontroller and uses a digital method to make a leakage judgment, which can make leakage detection more flexible and convenient. However, these circuits and methods are implemented at the circuit board level. If they are directly integrated into the chip, additional microprocessors or microcontrollers will cause the chip cost to increase dramatically. At the same time, according to the UL943 standard, the internal leakage protection that contains microcode through programming requires additional standard certification. This will increase the product design cycle and design cost. In addition, due to the performance limitations of microcontrollers or microprocessors, it is difficult to implement complex digital signal processing methods, so the final detection and decision performance is also greatly restricted.

Application content

The main purpose of the present application is to propose a leakage detection integrated circuit chip, a leakage detection protection circuit and electrical equipment, aiming to solve the problem that the existing leakage detection protection chip has poor anti-interference ability and is easy to trigger false protection actions.

In order to achieve the above purpose, the present application proposes a leakage detection integrated circuit chip, which is applied in a leakage detection protection circuit. The leakage detection protection circuit includes a current transformer, a thyristor and a trip unit; the leakage detection integrated circuit chip It includes a signal conversion circuit, a digital filter, a detection control circuit and a thyristor drive control circuit. The input terminal of the signal conversion circuit is connected to the output terminal of the current transformer, and the output terminal of the signal conversion circuit is in turn connected to the The digital filter, the detection control circuit and the thyristor drive control circuit are connected; the thyristor drive control circuit is also connected to the thyristor; wherein,

The signal conversion circuit is used to amplify the analog current detection signal received by the current transformer and convert it into a digital current detection signal for output;

The digital filter is used to filter the digital current detection signal;

The detection control circuit is configured to output a corresponding control signal according to the digital current detection signal output by the digital filter;

The thyristor drive control circuit is configured to drive the thyristor to be turned on to control the tripping unit when the control signal representing the current detection signal as the leakage current signal is output by the detection control circuit Trip action.

Optionally, the leakage detection integrated circuit chip further includes a serial logic circuit, a first input terminal of the serial logic circuit is connected to an output terminal of the detection control circuit, and a second input terminal of the serial logic circuit is external The output terminal of the SCR drive control circuit of the leakage detection integrated circuit chip;

The series logic circuit is configured to receive a control signal representing that the current detection signal is a leakage current signal after receiving the detection control circuit, and / or the thyristor drive of the external leakage detection integrated circuit chip When the driving signal output by the control circuit is triggered, the thyristor is turned on to control the tripping device to perform a tripping action.

Optionally, the signal conversion circuit includes a programmable gain amplifier and an A / D converter, the input terminal of the programmable gain amplifier is the input terminal of the signal conversion circuit, and the output terminal of the programmable gain amplifier is The input terminal of the A / D converter is connected, and the output terminal of the A / D converter is the output terminal of the signal conversion circuit.

Optionally, the leakage detection integrated circuit chip further includes a reference source circuit, an input terminal of the reference source circuit is used to access a power supply, and an output terminal of the reference source circuit is connected to the A / D converter; The reference source circuit is used to provide a reference power supply for the A / D converter.

Optionally, the digital filter includes a gain adjustment module, a down-sampling filter, a down-sampling module, and a band-pass filter that are sequentially connected to the signal conversion circuit.

Optionally, the detection control circuit includes a signal detection module and a delay control module connected to the digital filter in sequence; wherein,

The signal detection module is configured to detect the digital current detection signal output by the digital filter, and output a leakage detection signal when it is detected that the current value of the current detection signal is greater than a preset current threshold;

The delay control module is configured to generate a leakage protection action signal when the duration of receiving the leakage detection signal reaches a preset time or according to the frequency of receiving the leakage detection signal to trigger the conduction of the thyristor To control the tripping device to perform a tripping action.

Optionally, the leakage detection integrated circuit chip further includes a clock generation circuit, and an output end of the clock circuit is connected to a digital filter and a detection control circuit; the clock generation circuit is used for the digital filter and The detection control circuit provides a clock signal.

Optionally, the leakage detection integrated circuit chip further includes a memory, the memory and the signal conversion circuit, the digital filter, and the detection control circuit, respectively;

The memory is used to store parameter configurations corresponding to the signal conversion circuit, the digital filter, and the detection control circuit.

In this application, a signal conversion circuit is provided to pre-amplify the analog current detection signal received from the current transformer, convert it into a digital current detection signal, and then output to a digital filter to perform the digital current detection signal. After the filtering process, it is output to the detection control circuit, so that the detection control circuit outputs a corresponding control signal according to the digital detection signal output by the digital filter, so that the thyristor drive control circuit receives the detection control circuit When a control signal characterizing the leakage current signal is output, the thyristor is driven to be turned on to control the tripping device to perform a tripping action. The leakage detection and protection chip of the present application improves the anti-interference ability of electrical equipment. The application solves that when the short-term leakage current signal detected by the leakage detection and protection chip is an interference signal, it is easy to trigger false protection actions and control the electrical equipment to stop working , Causing the malfunction of the leakage protection device and affecting the normal use of the user.

BRIEF DESCRIPTION

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, without paying any creative work, other drawings can be obtained according to the structures shown in these drawings.

1 is a schematic structural diagram of an embodiment of an integrated circuit chip for leakage detection of the present application;

2 is a schematic structural diagram of another embodiment of an integrated circuit chip for leakage detection of the present application;

3 is a schematic structural diagram of yet another embodiment of an integrated circuit chip for leakage detection of the present application;

4 is a schematic structural diagram of yet another embodiment of an integrated circuit chip for leakage detection of the present application;

5 is a schematic structural diagram of still another embodiment of an integrated circuit chip for leakage detection of the present application.

Description of Drawing Symbols:

Label	name	Label	name
100	Current Transformer	twenty two	Downsampling filter
10	Signal conversion circuit	twenty three	Downsampling module
20	Digital filter	twenty four	Bandpass filter
30	Detection control circuit	31	Signal detection module
40	Thyristor drive control circuit	32	Delay control module
50	Series logic circuit	PIN1	SCR drive control circuit output
60	Reference source circuit	PIN2	Reference power input
70	Clock circuit	PIN3	Reference input
80	Memory	PIN4	Memory control input 1
31	Gain adjustment module	PIN5	Memory control input 2
D1	Clamp diode 1	PIN6	Programmable gain amplifier input 1
100	Current Transformer	PIN7	Programmable gain amplifier input 2
200	Rectifier circuit	PIN8	Series logic circuit second signal input terminal
300	SCR	D2	Clamp diode 2
400	Trip unit	500	Leakage detection integrated circuit chip
11	Programmable gain amplifier	12	A / D converter
twenty one	Gain adjustment module

The implementation, functional characteristics and advantages of the present application will be further described in conjunction with the embodiments and with reference to the drawings.

detailed description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application, the directional indication is only used to explain in a specific posture (as shown in the drawings) If the specific posture changes, the directional indication will change accordingly.

In addition, if there are descriptions related to "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are for descriptive purposes only, and cannot be understood as instructions or hints Its relative importance or implicitly indicates the number of technical features indicated. Thus, the features defined with "first" and "second" may include at least one of the features either explicitly or implicitly. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of those skilled in the art to realize. When the combination of technical solutions contradicts or cannot be realized, it should be considered that the combination of such technical solutions does not exist , Nor within the scope of protection required by this application.

The present application proposes a leakage detection integrated circuit chip, which is applied to electrical equipment with leakage detection and protection functions, such as electrical appliances such as electric water heaters and washing machines, or power sockets and power plugs with leakage detection and protection functions.

In the leakage detection and protection circuit, the leakage detection and protection circuit includes a main control chip, a sensor, a thyristor and a trip unit. When electrical equipment leaks, there is a part of the current in the electrical circuit that does not flow from the live wire back to the power supply through the neutral wire, but flows into the ground through the ground wire or the human body, which will cause electric shock when the user uses the electrical equipment. Danger. The electric leakage detection and protection circuit triggers the thyristor to conduct when it detects the electric leakage of the neutral wire or the live wire, so that the trip unit is energized and disconnected, thereby interrupting the external power supply to the electrical equipment. At present, due to the increasingly strict standards of human body electric shock protection, the leakage detection protection chip has higher requirements on the product parameters of peripheral devices, so it is necessary to accurately determine the leakage current, and the current leakage current detection circuit is susceptible to detection of leakage current. Interference signals from the outside world lead to protective actions that trigger errors.

In order to solve the above problems, referring to FIGS. 1 to 3, in an embodiment of the present application, the leakage detection integrated circuit chip includes a signal conversion circuit 10, a digital filter 20, a detection control circuit 30, and a thyristor drive control circuit 40 , The input terminal of the signal conversion circuit 10 is connected to the output terminal of the current transformer, the output terminal of the signal conversion circuit 10 is in turn connected to the digital filter 20, the detection control circuit 30 and the controllable The silicon drive control circuit 40 is connected; the thyristor drive control circuit 40 is also connected to the thyristor; wherein,

The signal conversion circuit 10 is used to amplify the analog current detection signal received by the current transformer and convert it into a digital current detection signal for output;

The digital filter 20 is used for filtering the digital current detection signal;

The detection control circuit 30 is configured to output a corresponding control signal according to the digital current detection signal output by the digital filter 20;

The thyristor drive control circuit 40 is configured to drive the thyristor to turn on to control the trip when receiving a control signal indicating that the current detection signal is a leakage current signal output by the detection control circuit 30 The device trips.

In this embodiment, the induction coil loop of the current transformer is provided on the outer periphery of the power line (live and neutral) or the outer periphery of the ground wire to detect the leakage current signal, and when the leakage current signal is detected, the current transformer ’s The output terminal generates a signal proportional to the leakage current, that is, a current detection signal, and outputs it to the signal conversion circuit 10. The current detection signal is an analog signal, and the signal conversion circuit 10 amplifies the signal after receiving the signal, and converts it into a digital current detection signal for output.

The digital filter 20 filters the digital current detection signal and outputs it to the detection control circuit 30. The detection control circuit 30 is used for judging and comparing according to the detected digital signal and a preset current threshold. Specifically, when the amplitude of the current detection signal is greater than the amplitude of the preset current threshold, it is determined that there is leakage. The detection control circuit 30 can also track the leakage current signal, for example, by setting a timer, when the duration of the leakage signal is counted, and when its duration reaches a preset threshold, it is determined that the leakage signal is not a false trigger signal , That is, it can output a control signal to the thyristor drive control circuit 40, thereby triggering the thyristor to turn on, and energizing the trip unit connected in this loop, thereby disconnecting the disconnect device in the loop and cutting off the power supply, Complete the leakage protection action. This setting can solve the problem of false triggering caused by sudden signal changes caused by glitches or sudden interference.

In this application, a signal conversion circuit 10 is provided to amplify the analog detection signal received from the current transformer, convert it into a digital signal, and then output it to a digital filter 20, thereby filtering the digital current detection signal After processing, it is output to the detection control circuit 30, so that the detection control circuit 30 outputs a corresponding control signal according to the digital current detection signal output by the digital filter 20, and then the thyristor drive control circuit 40 receives the When the detection control circuit 30 outputs a control signal characterizing the current detection signal as a leakage current signal, the thyristor is driven to conduct to control the tripping unit to perform a tripping operation. The leakage detection and protection chip of the present application improves the anti-interference ability of electrical equipment. The application solves that when the transient leakage current signal detected by the leakage detection and protection chip is an interference signal, it is easy to trigger false protection actions and control the electrical equipment to stop working , Causing the malfunction of the leakage protection device and affecting the normal use of the user.

Referring to FIGS. 1 to 3, in an alternative embodiment, the leakage detection integrated circuit chip further includes a series logic circuit 50, a first input terminal of the series logic circuit 50 and an output terminal of the detection control circuit 30 PIN1 connection, the second input terminal PIN8 of the serial logic circuit 50 is connected to the output terminal of the SCR drive control circuit 40 of the external leakage detection integrated circuit chip;

The series logic circuit 50 is configured to receive a control signal representing that the current detection signal is a leakage current signal when the detection control circuit 30 is received, and / or the controllability of the external leakage detection integrated circuit chip When the drive signal output by the silicon drive control circuit 40 triggers the thyristor to conduct to control the tripping device to perform a tripping action.

In this embodiment, the serial logic circuit 50 can be implemented using logic devices (gate circuits) such as AND gates, OR gates, and NAND gates, and in the same leakage detection integrated circuit chip, the serial logic circuit 50 can be provided with multiple The second input terminal, or a plurality of serial logic circuits 50 are provided, so that two or more leakage detection integrated circuit chips are connected in series, that is, the output terminal of the SCR drive control circuit 40 of the multiple leakage detection integrated circuit chips In the same leakage detection integrated circuit chip, the second input terminals of the serial logic circuit 50 are connected in a one-to-one correspondence. For example, in the two-way leakage detection integrated circuit chip, one of the leakage detection integrated circuit chip is connected to the input terminal of the other leakage detection integrated circuit chip through the output terminal of the thyristor drive control circuit 40, that is, the serial logic circuit 50 Two input terminals. In this way, by providing multiple leakage detection integrated circuit chips, when any leakage detection integrated circuit chip detects a leakage protection signal, it can trigger the action of the thyristor drive control circuit 40 in the same leakage detection integrated circuit chip to achieve leakage The detection and protection circuit detects and protects parts of the electrical equipment that are prone to leakage, so as to expand the scope of the leakage protection of the electrical equipment.

Referring to FIGS. 1 to 3, in an alternative embodiment, the signal conversion circuit 10 includes a programmable gain amplifier 11 and an A / D converter 12, and input terminals (PIN6, PIN7) of the programmable gain amplifier 11 Is the input terminal of the signal conversion circuit 10, the output terminal of the programmable gain amplifier 11 is connected to the input terminal of the A / D converter 12, and the output terminal of the A / D converter 12 is the signal The output of the conversion circuit 10.

The programmable gain amplifier 11 can be implemented by a current amplifier, a voltage amplifier or a transimpedance amplifier. The amplifier is used to amplify the leakage signal detected by the current transformer, and convert it into a digital signal through the A / D converter 12 to output. The gain programmable amplifier can be set as a differential input, or can be set as a single-ended input mode. In this embodiment, it can be selected as a differential input, that is, the two input terminals of the gain programmable amplifier are respectively connected to the output terminals of the current transformer.

In the above embodiment, the leakage detection integrated circuit further includes a clamping diode D2. Two diodes in the clamping diode D2 are connected in anti-parallel to the first signal input terminal and the second signal of the programmable gain amplifier 11 Between inputs.

1 to 3, in an alternative embodiment, the leakage detection integrated circuit chip further includes a reference source circuit 60, the input terminal PIN2 of the reference source circuit 60 is used to access the power supply, the reference source The output terminal of the circuit 60 is connected to the A / D converter 12; the reference source circuit 60 further includes a reference ground input PIN3. The reference source circuit 60 is used to convert the connected power supply to a reference power supply. The reference power supply for the A / D converter 12.

In this embodiment, the reference source circuit 60 is used to provide the A / D converter 12 and each circuit module in the chip with a highly stable voltage reference and / or current reference. After the chip is powered on, each module will perform power-on reset and set in the given order to ensure that the circuit performance works normally.

Referring to FIGS. 1 to 3, in an alternative embodiment, the digital filter 20 includes a gain adjustment module 21, a down-sampling filter 22, a down-sampling module 23, and a band-pass connected to the signal conversion circuit 10 in sequence. Filter 24.

Among them, the gain adjustment module 21 is used to precisely adjust the amplitude of the input signal so that the amplitude of the effective signal is within the set range, which can reduce the word length requirement of subsequent digital signal processing. The gain adjustment module 21 gain adjustment can multiply the input signal by a fixed multiple. For example, the gain adjustment range of the programmable gain amplifier 11 is generally greater than 60dB. When the gain adjustment module 31 is incremented by 0.1dB, it can cover from- 6dB to 6dB gain adjustment range. By cooperating with the programmable gain amplifier 11, precise gain adjustment can be realized within a very wide gain adjustment range. The specific gain setting value of the gain adjustment module 21 can be set by the clock generation circuit 70.

The down-sampling filter 22 can filter signals within the non-processing bandwidth to avoid signal aliasing during the down-sampling operation, and the down-sampling module 23 can reduce the sampling rate of the current detection signal, which can be specifically used to reduce the data transmission of the current detection signal Rate or data size, by down-sampling the input signal to a lower sampling frequency, the operating frequency of the subsequent band-pass filter 24 and detection control circuit 30 can be reduced, and the word length requirements of the filter can be reduced, thereby saving digital circuits Power consumption and area. For example, the signal frequency after downsampling is one or several frequencies between 30 Hz and 10 KHz, which corresponds to the sampling frequency of the front-end analog-to-digital converter. The downsampling multiple is between 8 and 100 times.

The digital signal down-sampled by the down-sampling module 23 is input to the band-pass filter 24, and the band-pass filter 24 is used to filter out interference signals outside the target frequency range. Specifically, the band-pass filter 24 can filter out high-frequency interference signals in the current detection signal, and enhance the anti-interference ability of the detection control circuit 30, so that the leakage detection characteristic of the overall chip has strong anti-interference ability. The band-pass filter 24 can also filter out DC and low-frequency components in the current detection signal to avoid their possible interference with the detection control circuit 30. Several different sets of band-pass filter 24 coefficients will be set within the chip at the same time, corresponding to different anti-interference ability and delay selection. When used for leakage current detection, the low-frequency cut-off frequency of the pass band of the band-pass filter 24 It can be set between 2 Hz and 55 Hz, and the high-frequency cutoff frequency is between 55 Hz and 150 Hz. The coefficients of different band-pass filters 24 can be set by the clock generation circuit 70.

Referring to FIGS. 1 to 3, in an alternative embodiment, the detection control circuit 30 includes a signal detection module 31 and a delay control module 32 that are sequentially connected to the digital filter 20; wherein,

The signal detection module 31 is configured to detect the digital current detection signal output by the digital filter 20, and output a leakage detection signal when it is detected that the current value of the current detection signal is greater than a preset current threshold;

The delay control module 32 is configured to generate a leakage protection action signal to trigger the thyristor when the duration of receiving the leakage detection signal reaches a preset time, or according to the frequency of receiving the leakage detection signal Turn on to control the tripping device to perform tripping action.

In this embodiment, the signal detection module 31 may use an operational amplifier or software integrated in the clock generation circuit 70 to implement signal detection and comparison. The signal detection module 31 is used to detect whether a sinusoidal signal whose amplitude is greater than a certain threshold exists in the current detection signal. The frequency of the leakage current signal can be a sine wave of 50 Hz or 60 Hz. Specific sine signal detection can directly detect whether the amplitude of the current detection signal output by the band-pass filter 24 is greater than the given decision threshold, and the amplitude of the current detection signal is greater than the given When the decision threshold is fixed, the signal can be determined as a leakage current signal. Alternatively, after the discrete Fourier transform of the current detection signal, it is calculated whether the signal power within the target frequency range is greater than the decision threshold. Or it can be calculated as follows:

Assuming that the input signal is X (t) and the target detection frequency is w, then calculate the average of (X (t) * Sin (wt)) ^ 2+ (X (t) * Cos (wt)) ^ 2 signal over a period of time Value to obtain the average power of the signal during this period. When the average power of the signal is greater than a given decision threshold, it can be judged that there is a sinusoidal signal with a frequency w, that is, a leakage current detection signal. In the signal detection module 31, one or more decision methods are designed. The selection of specific methods and the setting parameters of the decision threshold can be set by an electrically programmable clock generating circuit 70 in the chip.

The delay control module 32 may be implemented using electronic components such as logic devices (gate circuits) such as AND gates, OR gates, and NAND gates, timing controllers, timers, and D flip-flops. When a leakage current signal is detected, the delay control module 32 will track and observe the signal for a period of time to determine that the protection signal is not a false trigger. Therefore, malfunctions caused by possible glitches or sudden interference can be avoided. The specific setting parameters of the observation time and the delay time can be set by the electrically programmable clock generating circuit 70. The delay signal and the multiple clock signals required by the delay control module 32 are provided by the clock generation circuit 70.

Referring to FIGS. 1 to 3, in an alternative embodiment, the leakage detection integrated circuit chip further includes a clock generation circuit 70, an output terminal of the clock circuit is connected to the digital filter 20 and the detection control circuit 30; The clock generation circuit 70 is used to provide a clock signal to the digital filter 20 and the detection control circuit 30.

The clock generation circuit 70 can provide various clock signals required for the down-sampling module 23, the digital filter 20, the delay control module 32, and the like. In the clock generation circuit 70, the frequency and arrangement of the main clock and the multi-phase clock can be set by the on-chip electrically programmable clock generation circuit 70.

It should be noted that, at present, the leakage detection and protection circuit has a relatively large tolerance for the performance change of peripheral devices (such as the parameter characteristics of the transformer). Therefore, for the standard mandatory action threshold and the non-operation threshold, the leakage detection protection circuit is realized. The product yield rate at the time of rising is low. The

In order to solve the above problems, referring to FIGS. 1 to 3, in an alternative embodiment, the leakage detection integrated circuit chip further includes a memory 80, which is respectively connected to the signal conversion circuit 10 and the digital filter 20. The detection control circuit 30; the memory 80 is used to store parameter configurations corresponding to the signal conversion circuit 10, the digital filter 20, and the detection control circuit 30.

In this embodiment, the memory 80 may use on-chip electrically programmable memory 80, one-time programmable memory 80, multi-time programmable memory 80, electrically erasable programmable memory 80, flash memory, phase change memory 80, etc. One or more of the memories 80 are implemented. The memory 80 stores the parameter settings of each circuit module integrated with the leakage detection, and the pins 80 and 20 can be used to adjust the parameters of each circuit module. In this embodiment, the on-chip electrically programmable memory can be used to electrically adjust the parameters such as the leakage threshold of the chip, so that it can well match the off-chip devices with different parameter fluctuations, thereby improving the yield.

This application also proposes a leakage detection integrated circuit chip.

Referring to FIGS. 4 and 5, in an embodiment of the present application, the leakage detection protection circuit includes a plurality of sensors, thyristors, and trip units; characterized in that the leakage detection integrated circuit chip includes a plurality of signal conversions The circuit 10, the digital filter 20, the detection control circuit 30, and the thyristor drive control circuit 40, the input terminals of the plurality of signal conversion circuits 10 and the output terminals of the plurality of sensors are connected in a one-to-one correspondence, and the plurality of the The output end of the signal conversion circuit 10 is connected to the input end of the detection control circuit 30; the output end of the detection control circuit 30 is connected to the input end of the thyristor drive control circuit 40; the thyristor drive The output of the control circuit 40 is connected to the thyristor; wherein,

A plurality of the signal conversion circuits 10 are used to amplify the received analog detection signals output by the sensors and convert them into digital voltage signals for output, wherein the analog detection signals include a power supply voltage signal and a ground Detection signal, power supply voltage detection signal;

The digital filter 20 is used for filtering the digital voltage signal;

The detection control circuit 30 is configured to output a corresponding control signal according to the digital voltage signal output by the digital filter 20;

The thyristor drive control circuit 40 is configured to drive the thyristor to be turned on when the detection control circuit 30 outputs a control signal representing that the analog voltage signal is greater than a preset threshold to control the off The buckle performs a trip action.

In this embodiment, the sensor may be a sensor such as a voltage sensor, a current transformer, a temperature sensor, etc. The induction coil of the current transformer 100 is provided on the outer periphery of the power line (live and neutral) or the outer periphery of the ground wire to detect leakage When a leakage current signal is detected, the output terminal of the current transformer 100 generates a signal proportional to the leakage current, that is, a current detection signal, and outputs it to the signal conversion circuit 10. The current detection signal is an analog signal, and the signal conversion circuit 10 amplifies the signal after receiving the signal, and converts it into a digital current detection signal for output.

In this application, a signal conversion circuit 10 is provided to amplify the analog detection signal received from the sensor, convert it into a digital voltage signal, and then output it to a digital filter 20, so as to filter the digital voltage signal Output to the detection control circuit 30, so that the detection control circuit 30 outputs a corresponding control signal according to the digital voltage signal output by the digital filter 20, so that the thyristor drive control circuit 40 receives the detection control When the circuit 30 outputs a control signal characterizing the voltage signal as a leakage current signal, the thyristor is driven to conduct to control the tripping unit to perform a tripping operation. The leakage detection and protection chip of the present application improves the anti-interference ability of electrical equipment. The application solves that when the short-term leakage current signal detected by the leakage detection and protection chip is an interference signal, it is easy to trigger false protection actions and control the electrical equipment to stop working , Causing the malfunction of the leakage protection device and affecting the normal use of the user.

It can be understood that, in this embodiment, a multi-channel signal conversion circuit 10 is provided to access different voltage signals representing current detection, voltage detection, and temperature detection. For example, it is possible to detect whether there is a leakage voltage signal on the ground lead of the three-phase plug by connecting, or a voltage signal that detects current overload. Or the voltage signal of the overvoltage / undervoltage of the power supply voltage, so as to realize the leakage, overcurrent, overload, undervoltage or overvoltage protection of the electrical equipment.

It should be noted that the existing leakage detection and protection circuit may rarely have the function of ground fault detection or lack of a complete reverse wiring detection function. When the installer connects the power cord in reverse due to misoperation, the leakage detection and protection circuit It may not be able to perform the leakage protection function and lose its ground fault protection function. Therefore, the leakage detection protection circuit may have installation risks. When the power cord is reversed, it is often difficult for users to find out.

In order to solve the above problem, the leakage detection integrated circuit chip further includes an excitation circuit 50, an input terminal of the excitation circuit 50 and an output terminal of the detection control circuit 30, and the excitation circuit 50 (output terminal PIN8) are used for When receiving the control signal representing the ground fault of the electrical equipment, the detection control circuit 30 outputs a corresponding excitation signal.

In this embodiment, the excitation circuit 50 can be implemented using electronic components such as operational amplifiers, main control switches, etc., and the current signal in the ground wire is detected by the current transformer. When the detection control circuit 30 detects that the leakage detection protection circuit is in the working state Next, when the wiring error is caused by the installation wiring misoperation, the wiring error is displayed, and the corresponding control signal is output to the excitation circuit 50, so that the excitation circuit 50 outputs the excitation signal, which can characterize the detection of the short circuit of the ground wire and the neutral wire. Grounding error, and the excitation signal can be a power indication signal, or a switch drive signal, the excitation signal is output to the subsequent circuit, such as circuit breakers, indicator lights, etc. to characterize the grounding fault of the leakage detection protection circuit, to avoid wiring errors Circuit safety hidden danger caused by the failure of the leakage protection function.

4 to FIG. 5, in an alternative embodiment, each of the signal conversion circuit 10 includes a programmable gain amplifier 11 and an A / D converter 12, the programmable gain amplifier 11 has an input terminal (PIN6, PIN7) is the input terminal of the signal conversion circuit 10, the output terminal of the programmable gain amplifier 11 is connected to the input terminal of the A / D converter 12, the output terminal of the A / D converter 12 is The output terminal of the signal conversion circuit 10 is described.

The programmable gain amplifier 11 can be implemented by a current amplifier, a voltage amplifier or a transimpedance amplifier. The amplifier is used to amplify the leakage signal detected by the sensor and convert it into a digital signal through the A / D converter 12 to output. The gain programmable amplifier can be set as a differential input, or can be set as a single-ended input mode. In this embodiment, it can be selected as a differential input, that is, the two input terminals of the gain programmable amplifier are respectively connected to the output terminals of the sensor.

In the above embodiment, the leakage detection integrated circuit further includes a clamping diode D2. Two diodes in each clamping diode D2 are connected in anti-parallel to the first signal input terminal and the second of the programmable gain amplifier 11 Between signal input terminals. The first signal input terminal can be grounded.

The present application also proposes a leakage detection protection circuit, which includes a current transformer, a rectifier circuit, a thyristor, a trip unit, and the leakage detection integrated chip as described above;

The input terminal of the rectifier circuit is used to connect to an AC power supply, the current transformer is used to detect leakage signals and grounding error signals, and the coil loop of the current transformer is provided on the outer periphery of the live wire and the neutral wire and the rectifier The input end of the circuit is connected, and the output end of the current transformer is sequentially connected to the leakage detection integrated chip, the thyristor, and the release.

The thyristor is based on the control of the leakage detection integrated chip to be turned on when the trigger signal output by the leakage detection integrated chip is received so that the iron core of the tripping device can transmit the tripping action to the tripping mechanism after being electrically engaged , Complete the tripping action, so that when the electrical equipment leakage occurs, the electrical equipment can be protected against leakage.

The present application also proposes a leakage detection and protection circuit, which includes a current transformer, a rectifier circuit, a thyristor, a trip unit, and a leakage detection integrated circuit chip as described above;

The input terminal of the rectifier circuit is used to connect to an AC power supply, the current transformer is used to detect leakage signals and grounding error signals, and the coil loop of the current transformer is provided on the outer periphery of the live line and the neutral line The input end of the circuit is connected, and the output end of the current transformer is sequentially connected to the leakage detection integrated circuit chip, the thyristor, and the release.

The thyristor is based on the control of the leakage detection integrated circuit chip, so as to be turned on when the trigger signal output by the leakage detection integrated circuit chip is received, so that the iron core transmits the tripping action to the tripping after the tripping is obtained The buckle mechanism completes the tripping action, so that when the electrical equipment has a leakage phenomenon, the electrical equipment can be protected against leakage.

The present application also proposes an electrical device including the leakage detection integrated chip as described above or the leakage detection protection circuit as described above. It can be understood that, since the above-mentioned leakage detection integrated chip and leakage detection protection circuit are used in the electrical equipment of this application, the embodiments of the electrical equipment of this application include all of the above embodiments of the above leakage detection integrated chip and leakage detection protection circuit The technical solution, and the technical effects achieved are also the same, and will not be repeated here.

The above are only the preferred embodiments of the present application, and therefore do not limit the patent scope of the present application. Any equivalent structural transformations made by using the contents of the description and drawings of the present application or direct / indirect use under the application concept of the present application All other related technical fields are included in the patent protection scope of this application.

Claims

An electric leakage detection integrated circuit chip is used in an electric leakage detection protection circuit. The electric leakage detection protection circuit includes a current transformer, a thyristor and a trip unit; wherein the electric leakage detection integrated circuit chip includes a signal conversion circuit and a digital A filter, a detection control circuit and a thyristor drive control circuit, the input terminal of the signal conversion circuit is connected to the output terminal of the current transformer, and the output terminal of the signal conversion circuit is in turn connected to the digital filter and the The detection control circuit and the thyristor drive control circuit are connected; the thyristor drive control circuit is also connected to the thyristor; wherein,

The signal conversion circuit is used to amplify the analog current detection signal received by the current transformer and convert it into a digital current detection signal for output;

The digital filter is used to filter the digital current detection signal;

The detection control circuit is configured to output a corresponding control signal according to the digital current detection signal output by the digital filter;

The thyristor drive control circuit is configured to drive the thyristor to be turned on to control the tripping unit when the control signal representing the current detection signal as the leakage current signal is output by the detection control circuit Trip action.
The leakage detection integrated circuit chip according to claim 1, wherein the leakage detection integrated circuit chip further comprises a serial logic circuit, a first input terminal of the serial logic circuit is connected to an output terminal of the detection control circuit, The second input terminal of the series logic circuit is connected to the output terminal of the thyristor drive control circuit of the external leakage detection integrated circuit chip;

The series logic circuit is configured to receive a control signal representing that the current detection signal is a leakage current signal after receiving the detection control circuit, and / or the thyristor drive of the external leakage detection integrated circuit chip When the driving signal output by the control circuit is triggered, the thyristor is turned on to control the tripping device to perform a tripping action.
The leakage detection integrated circuit chip according to claim 1, wherein the signal conversion circuit includes a programmable gain amplifier and an A / D converter, and an input terminal of the programmable gain amplifier is an input terminal of the signal conversion circuit The output terminal of the programmable gain amplifier is connected to the input terminal of the A / D converter, and the output terminal of the A / D converter is the output terminal of the signal conversion circuit.
The leakage detection integrated circuit chip according to claim 3, wherein the leakage detection integrated circuit chip further includes a reference source circuit, an input terminal of the reference source circuit is used to access a power supply, and an output of the reference source circuit The terminal is connected to the A / D converter; the reference source circuit is used to provide a reference power supply for the A / D converter.
The leakage detection integrated circuit chip according to claim 1, wherein the digital filter includes a gain adjustment module, a down-sampling filter, a down-sampling module, and a band-pass filter that are sequentially connected to the signal conversion circuit.
The leakage detection integrated circuit chip according to claim 1, wherein the detection control circuit includes a signal detection module and a delay control module connected to the digital filter in sequence; wherein,

The signal detection module is configured to detect the digital current detection signal output by the digital filter, and output a leakage detection signal when it is detected that the current value of the current detection signal is greater than a preset current threshold;

The delay control module is configured to generate a leakage protection action signal to trigger the thyristor when the duration of receiving the leakage detection signal reaches a preset time or according to the frequency of occurrence of the leakage detection signal received To control the tripping device to perform a tripping action.
The leakage detection integrated circuit chip according to claim 1, wherein the leakage detection integrated circuit chip further includes a clock generation circuit, an output end of the clock circuit is connected to a digital filter and a detection control circuit; the clock generation circuit , Used to provide a clock signal for the digital filter and the detection control circuit.
The leakage detection integrated circuit chip according to claim 1, wherein the leakage detection integrated circuit chip further comprises a memory, the memory and the signal conversion circuit, the digital filter, and the detection control circuit, respectively;

The memory is used to store parameter configurations corresponding to the signal conversion circuit, the digital filter, and the detection control circuit.
An electric leakage detection integrated circuit chip is used in an electric leakage detection and protection circuit. The electric leakage detection and protection circuit includes a plurality of sensors, a thyristor and a release; wherein the electric leakage detection integrated circuit chip includes a plurality of signal conversion circuits , Digital filter, detection control circuit and thyristor drive control circuit, the input terminals of the plurality of signal conversion circuits and the output terminals of the plurality of sensors are connected in one-to-one correspondence, and the output terminals of the plurality of signal conversion circuits Respectively connected to the input end of the detection control circuit; the output end of the detection control circuit is connected to the input end of the thyristor drive control circuit; the output end of the thyristor drive control circuit is connected to the controllable Silicon connection;

A plurality of the signal conversion circuits are used to amplify the received analog detection signals output by the sensors and convert them into digital voltage signals for output, wherein the analog detection signals include power supply voltage signals and ground detection Signals, power supply voltage detection signals, and / or ground fault detection signals;

The digital filter is used to filter the digital voltage signal;

The detection control circuit is configured to output a corresponding control signal according to the digital voltage signal output by the digital filter;

The thyristor drive control circuit is used to drive the thyristor to turn on when the detection control circuit outputs an analog voltage signal characterizing that the analog voltage signal is greater than a preset amplitude threshold, and reaches the timing time, To control the tripping device to perform a tripping action.
The leakage detection integrated circuit chip according to claim 9, wherein the leakage detection integrated circuit chip further includes an excitation circuit, an input end of the excitation circuit and an output end of the detection control circuit, the excitation circuit is used When receiving the control signal representing the ground fault of the electrical equipment, the detection control circuit outputs a corresponding excitation signal.
The leakage detection integrated circuit chip according to claim 9, wherein each of the signal conversion circuits includes a programmable gain amplifier and an A / D converter, and the input terminal of the programmable gain amplifier is the signal conversion circuit At the input end, the output end of the programmable gain amplifier is connected to the input end of the A / D converter, and the output end of the A / D converter is the output end of the signal conversion circuit.
The leakage detection integrated circuit chip according to claim 9, wherein the leakage detection integrated circuit chip further comprises a serial logic circuit, the first input terminal of the serial logic circuit is connected to the output terminal of the detection control circuit, The second input terminal of the series logic circuit is connected to the output terminal of the thyristor drive control circuit of the external leakage detection integrated circuit chip;

The series logic circuit is configured to receive a control signal representing that the current detection signal is a leakage current signal after receiving the detection control circuit, and / or the thyristor drive of the external leakage detection integrated circuit chip When the driving signal output by the control circuit is triggered, the thyristor is turned on to control the tripping device to perform a tripping action.
The leakage detection integrated circuit chip according to claim 9, wherein the digital filter includes a gain adjustment module, a down-sampling filter, a down-sampling module, and a band-pass filter that are sequentially connected to the signal conversion circuit.
The leakage detection integrated circuit chip according to claim 9, wherein the detection control circuit includes a signal detection module and a delay control module connected to the digital filter in sequence; wherein,

The signal detection module is configured to detect the digital voltage signal output by the digital filter, and output a leakage detection signal when it is detected that the current value of the voltage signal is greater than a preset current threshold;

The delay control module is configured to generate a leakage protection action signal when the duration of receiving the leakage detection signal reaches a preset time or according to the frequency of receiving the leakage detection signal to trigger the conduction of the thyristor To control the tripping device to perform a tripping action.
A leakage detection protection circuit, wherein the leakage detection protection circuit includes a current transformer, a rectifier circuit, a thyristor, a trip unit, and the leakage detection integrated circuit chip according to claim 1;

The input terminal of the rectifier circuit is used to connect to an AC power source, the current transformer is used to detect leakage signals and grounding error signals, and the coil loop of the current transformer is provided on the outer periphery of the live and neutral wires. The output terminal of the transformer is connected to the leakage detection integrated circuit chip, the thyristor and the release in sequence.
An electric appliance, comprising the leakage detection integrated circuit chip according to claim 1, or the leakage detection integrated circuit according to claim 9. The