CN113687134A - Current sensor circuit with comprehensive diagnosis function and current sensor - Google Patents
Current sensor circuit with comprehensive diagnosis function and current sensor Download PDFInfo
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- CN113687134A CN113687134A CN202110980785.3A CN202110980785A CN113687134A CN 113687134 A CN113687134 A CN 113687134A CN 202110980785 A CN202110980785 A CN 202110980785A CN 113687134 A CN113687134 A CN 113687134A
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- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/16576—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 comparing DC or AC voltage with one threshold
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Abstract
The invention discloses a current sensor circuit with a comprehensive diagnosis function and a current sensor, comprising a power supply circuit, a magnetoelectric conversion circuit, a proportional amplification output circuit, a proportional amplification and small signal diagnosis circuit, a voltage diagnosis circuit and a logic and triode open-circuit output circuit; the magnetoelectric conversion circuit inputs a measured current signal from a through hole of the current sensor, generates a magnetic field according to the current periphery, and carries out electromagnetic conversion on the measured current signal to obtain a magnetic field signal; the magnetic gathering ring is used for gathering, the gathered magnetic field signal is sensed through a Hall device element, and the magnetic field signal is subjected to magnetoelectric conversion to obtain a processed electric signal; according to the invention, two paths of signals after being diagnosed by combining the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit are logically ANDed and output through a triode open circuit. The invention has the advantages of quick response, simple circuit and structure, low cost, high reliability, electromagnetic interference resistance, no digital chip and software, and the like, and is very suitable for application in special industries.
Description
Technical Field
The invention relates to the technical field of current measurement, in particular to a current sensor circuit with a comprehensive diagnosis function and a current sensor.
Background
The onboard +28V direct current power supply system provides power for various electric equipment, and the quality of the onboard +28V direct current power supply system plays a key role in the whole system and control equipment. It is therefore necessary to detect the power load current and voltage.
At present, the direct current detection of an airborne power distribution system is generally carried out in a Hall current sensor mode, the working and load conditions of a power supply can be visually obtained through the linear detection of the total current of the power supply system, and meanwhile, an alarm signal can be rapidly given out when the power supply system is overloaded.
In the field of onboard power distribution, there are special requirements for diagnosing low current conditions. If the linear output value is adopted for small current diagnosis, the linear output value is small when the linear detection range is wide and the small current signal is input, so that the small current diagnosis is easily interfered by the outside. If a small current detection is added, the reliability of the product is reduced on the basis of increasing redundancy, complexity and cost.
Meanwhile, the power supply system of the airborne sensor needs to provide self-diagnosis for the +28V power supply system besides meeting the power supply characteristic requirement of the GJB181A airplane.
At present, no pure analog circuit scheme for comprehensively diagnosing the power supply voltage and the load current exists in the market, and the response time and the cost volume of the comprehensive digital circuit scheme can not meet the requirements of the system.
Disclosure of Invention
The invention aims to solve the technical problem that a current sensor in the existing airborne power distribution system detects the condition of small current, and the linear output value is small when the small current signal is input due to a wider linear detection range, so that the current sensor is easily interfered by the outside; if a small current detection is added, the problems of product reliability and the like are also reduced on the basis of adding redundancy, complexity and cost.
The invention aims to provide a current sensor circuit with a comprehensive diagnosis function and a current sensor, and the current sensor designed by the invention is very suitable for being applied in the fields of high environmental requirements, high precision and small volume and mass; the invention can be used for the linear detection of the direct current of the power distribution system, diagnoses the power supply and the power load of the sensor, provides the analog switching value signal output according to the diagnosed condition, and can quickly cut off the system power supply for protection and fault detection.
The invention is realized by the following technical scheme:
in a first aspect, the invention provides a current sensor circuit with a comprehensive diagnosis function, which comprises a power characteristic circuit, a magnetoelectric conversion circuit, a proportional amplification output circuit, a proportional amplification and small signal diagnosis circuit, a voltage diagnosis circuit and a logic and triode open-circuit output circuit;
the power supply characteristic circuit is used for converting an onboard +28V auxiliary power supply into low voltage (VCC about 10V) for use by each rear-stage module circuit;
the magnetoelectric conversion circuit is used for inputting a current signal to be measured from a through hole of the current sensor, generating a magnetic field according to the current periphery and electromagnetically converting the current signal to be measured to obtain a magnetic field signal; because the magnetic field signals are comparatively diffused, the magnetic gathering ring is used for gathering, the gathered magnetic field signals are sensed through the Hall device element, and the magnetic field signals are subjected to magnetoelectric conversion to obtain processed electric signals;
the proportional amplification output circuit is used for carrying out secondary amplification processing on the processed electric signal to obtain a standard linear output signal; wherein, the small signal after the first-stage amplification processing is input to the proportional amplification and small signal diagnosis circuit;
the proportion amplification and small signal diagnosis circuit is used for acquiring the small signal after the first-stage amplification processing of the proportion amplification output circuit, performing further amplification processing by adjustable amplification factor, and comparing the processed small signal with a reference voltage through a hysteresis comparator: when the measured current is smaller than the preset current value, outputting high voltage (close to VCC); when the measured current is more than 25A, the comparator outputs low voltage (close to 0V); and outputs a logic level signal;
the voltage diagnostic circuit is used for comparing the input voltage with a reference voltage: outputting a high voltage (close to VCC) when the power supply voltage is higher than a first voltage preset value; outputting a low voltage (close to 0V) when the auxiliary power supply is lower than a second voltage preset value; and outputs a logic level signal;
and the logic and triode open-circuit output circuit is used for realizing the AND gate function of a hardware circuit through the simplest diode logic and of two paths of signals diagnosed by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit and outputting the two paths of signals through triode open circuits.
The working principle is as follows: the current sensor in the existing airborne power distribution system detects the low current condition, and the linear output value is small when a low current signal is input due to a wider linear detection range, so that the current sensor is easily interfered by the outside; if a small current detection is added, the problems of product reliability and the like are also reduced on the basis of adding redundancy, complexity and cost. The method is characterized in that a current sensor in an onboard power distribution system detects the low current condition in a digital form in cooperation with a software program, so that a plurality of sensors are needed, the cost is high, the software program is complex, the reliability is low and the like.
Therefore, the invention adopts the technical scheme to design the current sensor circuit with the comprehensive diagnosis function, and the invention adopts the Hall current sensor principle to measure the direct current 200A of the airborne primary distribution system, can be overloaded to 900A (short time) and is converted into a standard 2V tracking direct current signal to be output. On the basis, a small current and auxiliary power supply diagnosis function is added, when the measured current is smaller than a certain current value (15A) and the power supply voltage is higher than a certain value (16V), the power supply voltage (+28V) is output, and when the measured current is larger than 25A and the auxiliary power supply is lower than a certain value (14V), the output is open-circuited. The + 28V/open circuit is that the switching value output signal has the driving capability not less than 20 mA.
The current sensor circuit is realized by adopting a logic circuit, and has strong anti-interference capability; thereby ensuring that the current sensor is very suitable for being applied in the fields of high environmental requirements, high precision and small volume and mass; the invention can be used for the linear detection of the direct current of the power distribution system, diagnoses the power supply and the power load of the sensor, provides the analog switching value signal output according to the diagnosed condition, and can quickly cut off the system power supply for protection and fault detection.
Further, the power characteristic circuit comprises a fuse F1, a transient suppression diode F2, an NPN triode Q1, an adjustable reference N1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, wherein one end of the fuse F1 is connected to an onboard +28V auxiliary power supply, the other end of the fuse F1 is connected with a resistor R1, the resistor R1 is connected with a pin 2 of the NPN triode Q1, a pin 1 of the NPN triode Q1 is connected with a pin 2 of the adjustable reference N1, and a pin 3 of the NPN triode Q1 is grounded;
one end of the transient suppression diode F2 is connected with the common end of the fuse F1 and the resistor R1, and the other end is grounded; one end of the capacitor C1 is connected with the common end of the pin 2 of the resistor R1 and the NPN triode Q1, the other end of the capacitor C1 is grounded, and the resistor R1 and the capacitor C1 form a first-order RC passive filter circuit;
one end of the resistor R2 is connected with a pin 2 of an NPN triode Q1, and the other end of the resistor R2 is connected with a pin 1 of an NPN triode Q1;
the resistor R3 and the resistor R4 are connected in series, and the capacitor C2 is connected in parallel with a first-order RC passive filter circuit consisting of the resistor R1 and the capacitor C1; the common ends of the resistor R3 and the resistor R4 are connected with a pin 1 of the adjustable reference N1; capacitor C2 has one end connected to VCC and the other end connected to ground.
Among other things, fuse F1 provides protection for the current sensor circuit, and when a product is shorted or fails, the fuse blows to protect the entire power system of the customer from damage. The transient suppression diode F2, the resistor R1 and the capacitor C1 form a first-order RC passive filter circuit, so that the product can be effectively prevented from being impacted by surge voltage. The wide input voltage circuit composed of the NPN triode Q1, the AZ431 adjustable reference N1, the resistor R1, the resistor R2, the resistor R3 and the capacitor C2 can meet the requirements of overvoltage, undervoltage, transient and the like required by the GJB 181A.
Furthermore, the magnetoelectric conversion circuit comprises an AZ431 adjustable reference N2 and a PNP triode Q2, a constant current source circuit consisting of the AZ431 adjustable reference N2 and the PNP triode Q2 provides drive for an HG302 gallium arsenide Hall element H1, and the unbalanced temperature drift of an H1 Hall bridge is compensated by using the temperature drift of a PN junction of the triode Q2, so that the precision of the measured current in the full temperature range can be ensured.
Further, the two-stage amplification processing comprises differential amplification processing and in-phase amplification processing, and the two-stage amplification processing can effectively ensure that the current sensor line is linearly amplified to a standard linear output OUT.
Furthermore, the magnetic gathering ring adopts a square structural form, so that the influence of electromagnetic stress generated by large current on the air gap of the magnetic ring can be effectively reduced; the magnetic core of the magnetic gathering ring is formed by stamping permalloy materials with high magnetic conductivity and low coercive force, and the influence of residual magnetism caused by small current detection precision and large current impact of a product can be effectively improved.
Further, the proportional amplification and small signal diagnosis circuit comprises an amplifier N5A and a hysteresis comparator N5B, a pin 3 of the amplifier N5A is connected with a small signal after primary amplification processing of the proportional amplification output circuit, a pin 2 of the amplifier N5A is connected with a pin 1 of the amplifier N5A through a resistor, a pin 1 of the amplifier N5A is connected with a pin 6 of the hysteresis comparator N5B, and a pin 5 of the hysteresis comparator N5B is connected with a reference voltage circuit through a resistor; pin 7 of the hysteresis comparator N5B serves as an output terminal and is connected to the input terminal of the and transistor open circuit output circuit.
Further, the supply voltage diagnostic uses a hysteresis comparison as well as the low current diagnostic.
Further, the logic and triode open-circuit output circuit comprises a diode D1, a diode D2, a photoelectric coupler N7, an NPN triode Q3, a resistor R27, a resistor R28, a resistor R29 and a resistor R30; the cathode of the diode D2 is connected with the output end of the proportional amplifying and small signal diagnosing circuit, and the anode of the diode D2 is connected with the anode of the diode D1; the cathode of the diode D1 is connected with a pin 1 of a photoelectric coupler N7, a pin 2 and a pin 3 of the photoelectric coupler N7 are both grounded, a pin 4 of the photoelectric coupler N7 is connected with an emitter of an NPN triode Q3 through a resistor R29, a pin 4 of the photoelectric coupler N7 is also connected with a base of the NPN triode Q3 through a resistor R30, and a collector of the NPN triode Q3 serves as an output KO;
one end of the resistor R28 is connected with the common end of the diode D1 and the pin 1 of the photoelectric coupler N7, and the other end of the resistor R28 is grounded; the resistor R27 is connected with the output end of the voltage diagnosis circuit;
when the voltages output by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit are both high level, the photoelectric coupler N7 works, so that the NPN triode Q3 is in saturated conduction; otherwise, the photoelectric coupler N7 does not work, the NPN triode Q3 does not work, and the NPN triode Q3 is in an open circuit state; thereby, the KO output is the auxiliary power supply voltage or the open circuit to realize the product comprehensive diagnosis function. Because the NPN triode is in a saturated conduction state when being conducted, the CE level of the triode has lower voltage drop, the output voltage of the collector is closer to the power voltage, and meanwhile, the driving capability is better.
In a second aspect, the invention further provides a current sensor with a comprehensive diagnosis function, which comprises an outer shell, wherein the current sensor circuit with the comprehensive diagnosis function is arranged in the outer shell, and the current sensor circuit is designed by adopting a multilayer board; the shell body is made of aviation aluminum and has a shielding function.
Furthermore, the current sensor is used for linear detection of direct current of a primary power distribution system, diagnosis of power supply and power load conditions of the current sensor is carried out, analog switching value signal output is provided according to the diagnosis condition, and rapid cut-off of a system power supply for protection and fault detection is achieved.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the invention combines the comprehensive diagnosis mode of the small current signal diagnosis circuit and the voltage diagnosis circuit, and can automatically shut off the onboard 28V power supply condition by the sensor when the load current is abnormal (higher than a certain threshold value) and the power supply voltage is abnormal (lower than a certain threshold value), thereby achieving the purpose of protecting the load design and the power supply system.
2. Compared with the traditional digital system diagnosis, the circuit has the advantages of fast response, strong anti-interference capability, simple circuit and structure, low cost, high reliability (anti-electromagnetic interference), no digital chip, no software and the like, and is very suitable for application in special industries.
3. The current sensor is very suitable for being applied in the fields of high environmental requirements, high precision and small volume and mass; the invention can be used for the linear detection of the direct current of the power distribution system, diagnoses the power supply and the power load of the sensor, provides the analog switching value signal output according to the diagnosed condition, and can quickly cut off the system power supply for protection and fault detection.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principles of the invention. In the drawings:
fig. 1 is a block diagram of a current sensor circuit with integrated diagnostic function according to the present invention.
Fig. 2 is a detailed circuit diagram of a current sensor circuit with integrated diagnostic function according to the present invention.
Fig. 3 is a schematic view of the magnetic convergence ring of the present invention.
Fig. 4 is a circuit diagram of a power supply characteristic circuit of the present invention.
Fig. 5 is a circuit diagram of a magneto-electric conversion circuit of the present invention.
FIG. 6 is a circuit diagram of a scaled output circuit according to the present invention.
FIG. 7 is a circuit diagram of the scale up and small signal diagnostic circuit and the voltage diagnostic circuit of the present invention.
FIG. 8 is a circuit diagram of the logic AND and transistor open circuit output circuit of the present invention.
Fig. 9 is a structural diagram of a current sensor with integrated diagnostic function according to the present invention.
Reference numbers and corresponding part names:
1-outer shell.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples and accompanying drawings, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not meant to limit the present invention.
The invention adopts the Hall current sensor principle to measure the direct current 200A of the airborne primary distribution system, can be overloaded to 900A (short time), and is converted into a standard 2V tracking direct current signal for output. On the basis, a small current and auxiliary power supply diagnosis function is added, when the measured current is smaller than a certain current value (15A) and the power supply voltage is higher than a certain value (16V), the power supply voltage (+28V) is output, and when the measured current is larger than 25A and the auxiliary power supply is lower than a certain value (14V), the output is open-circuited. The + 28V/open circuit is that the switching value output signal has the driving capability not less than 20 mA.
Example 1
As shown in fig. 1, the current sensor circuit with comprehensive diagnosis function of the present invention includes a power characteristic circuit, a magnetoelectric conversion circuit, a proportional amplification output circuit, a proportional amplification and small signal diagnosis circuit, a voltage diagnosis circuit, and a logic and triode open circuit output circuit;
the power supply characteristic circuit is used for converting an onboard +28V auxiliary power supply into low voltage (VCC about 10V) for use by each rear-stage module circuit;
the magnetoelectric conversion circuit is used for inputting a current signal to be measured from a through hole of the current sensor, generating a magnetic field according to the current periphery and electromagnetically converting the current signal to be measured to obtain a magnetic field signal; because the magnetic field signals are comparatively diffused, the magnetic gathering ring is used for gathering, the gathered magnetic field signals are sensed through the Hall device element, and the magnetic field signals are subjected to magnetoelectric conversion to obtain processed electric signals;
the proportional amplification output circuit is used for carrying out secondary amplification processing on the processed electric signal to obtain a standard linear output signal; wherein, the small signal after the first-stage amplification processing is input to the proportional amplification and small signal diagnosis circuit;
the proportion amplification and small signal diagnosis circuit is used for acquiring the small signal after the first-stage amplification processing of the proportion amplification output circuit, performing further amplification processing by adjustable amplification factor, and comparing the processed small signal with a reference voltage through a hysteresis comparator: when the measured current is smaller than the preset current value, outputting high voltage (close to VCC); when the measured current is more than 25A, the comparator outputs low voltage (close to 0V); and outputs a logic level signal;
the voltage diagnostic circuit is used for comparing the input voltage with a reference voltage: outputting a high voltage (close to VCC) when the power supply voltage is higher than a first voltage preset value; outputting a low voltage (close to 0V) when the auxiliary power supply is lower than a second voltage preset value; and outputs a logic level signal;
and the logic and triode open-circuit output circuit is used for realizing the AND gate function of a hardware circuit through the simplest diode logic and of two paths of signals diagnosed by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit and outputting the two paths of signals through triode open circuits.
Fig. 2 is a detailed circuit diagram of a current sensor circuit with integrated diagnostic function. Each circuit module is specifically realized as follows:
in this embodiment, as shown in fig. 4, the power characteristic circuit includes a fuse F1, a transient suppression diode F2, an NPN triode Q1, an adjustable reference N1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1, and a capacitor C2, one end of the fuse F1 is connected to an onboard +28V auxiliary power supply, and the other end of the fuse F1 is connected to the resistor R1, the resistor R1 is connected to a pin 2 of the NPN triode Q1, a pin 1 of the NPN triode Q1 is connected to a pin 2 of the adjustable reference N1, and a pin 3 of the triode NPN Q1 is grounded;
one end of the transient suppression diode F2 is connected with the common end of the fuse F1 and the resistor R1, and the other end is grounded; one end of the capacitor C1 is connected with the common end of the pin 2 of the resistor R1 and the NPN triode Q1, the other end of the capacitor C1 is grounded, and the resistor R1 and the capacitor C1 form a first-order RC passive filter circuit;
one end of the resistor R2 is connected with a pin 2 of an NPN triode Q1, and the other end of the resistor R2 is connected with a pin 1 of an NPN triode Q1;
the resistor R3 and the resistor R4 are connected in series, and the capacitor C2 is connected in parallel with a first-order RC passive filter circuit consisting of the resistor R1 and the capacitor C1; the common ends of the resistor R3 and the resistor R4 are connected with a pin 1 of the adjustable reference N1; capacitor C2 has one end connected to VCC and the other end connected to ground.
Among other things, fuse F1 provides protection for the current sensor circuit, and when a product is shorted or fails, the fuse blows to protect the entire power system of the customer from damage. The transient suppression diode F2, the resistor R1 and the capacitor C1 form a first-order RC passive filter circuit, so that the product can be effectively prevented from being impacted by surge voltage. The wide input voltage circuit composed of the NPN triode Q1, the AZ431 adjustable reference N1, the resistor R1, the resistor R2, the resistor R3 and the capacitor C2 can meet the requirements of overvoltage, undervoltage, transient and the like required by the GJB 181A.
In this embodiment, as shown in fig. 5, the magnetoelectric conversion circuit includes an AZ431 adjustable reference N2 and a PNP triode Q2, a constant current source circuit composed of an AZ431 adjustable reference N2 and a PNP triode Q2 provides drive for an HG302 gallium arsenide hall element H1, and the unbalanced temperature drift of an H1 hall bridge is compensated by using the temperature drift of a PN junction of a triode Q2, so that the accuracy of the measured current in the full temperature range can be ensured.
In this embodiment, as shown in fig. 6, the two-stage amplification process in the proportional amplification output circuit includes a differential amplification process and an in-phase amplification process, and the two-stage amplification process is composed of resistors R9 to R14 and high-precision operational amplifiers N3A and N3B. The two-stage amplification treatment can effectively ensure that the current sensor line is linearly amplified to a standard linear output OUT.
In this embodiment, as shown in fig. 3, the magnetic convergence ring adopts a square structural form, which can effectively reduce the influence of electromagnetic stress generated by large current on the air gap of the magnetic ring; the magnetic core of the magnetic gathering ring is formed by stamping permalloy materials with high magnetic conductivity and low coercive force, and the influence of residual magnetism caused by small current detection precision and large current impact of a product can be effectively improved.
In this embodiment, as shown in fig. 7, the proportional amplification and small signal diagnosis circuit includes an amplifier N5A and a hysteresis comparator N5B, a pin 3 of the amplifier N5A is connected to a small signal after the first-stage amplification processing of the proportional amplification output circuit, a pin 2 of the amplifier N5A is connected to a pin 1 of the amplifier N5A through a resistor, a pin 1 of the amplifier N5A is connected to a pin 6 of the hysteresis comparator N5B, and a pin 5 of the hysteresis comparator N5B is connected to a reference voltage circuit through a resistor; pin 7 of the hysteresis comparator N5B serves as an output terminal and is connected to the input terminal of the and transistor open circuit output circuit.
The small current detection is directly extracted from a branch of the linear detection (the detection is carried out by sharing a magnetic core and a Hall element), when a small current signal passes through a bus bar or a lead and is penetrated through a current sensor through hole (figure 9), a magnetic field generated by current is gathered by a magnetic gathering ring, and the strength is strongest at an opening of the magnetic core. The hall element H1 is placed at the very center of the opening of the magnetic core, and a hall potential is generated at the 2-pin and 4-pin of H1 by the hall effect principle. Because the Hall potential generated by small current signals needs to be directly amplified after being very weak extracted, the V01 signal output by the first-stage amplification forms a second-stage amplification through a resistor (R16-R18) and a high-precision operational amplifier N5A and is sent to a hysteresis comparator, and therefore the interference caused by the transmission of the traditional small-signal single sampling output signal can be effectively reduced by outputting a logic level signal after internal diagnosis. In addition, in the conventional mode, the small current is detected and then independently output, so that the cost of one path of small current detection and the complexity of a product need to be increased, and the reliability of the product is reduced.
The small signal after the second-stage amplification is connected into a reverse input hysteresis comparator with double thresholds, which is composed of a high-precision operational amplifier N5B, R19, R20 and R21, through R19. The comparison reference voltage is generated by the R14 resistor and the AZ431 adjustable reference N4. According to the characteristics and the functional requirements of the hysteresis comparator, the threshold voltage parameter is reasonably designed to ensure that the circuit has the advantages that when the measured current is smaller than a certain current value (15A), the comparator outputs high voltage (close to VCC), and when the measured current is larger than 25A, the comparator outputs low voltage (close to 0V). The anti-interference capability of the hysteresis comparator is greatly improved due to the existence of the return difference of the hysteresis comparator.
In the present embodiment, similarly, the power supply voltage diagnosis and the low current diagnosis use the hysteresis comparison. As shown in fig. 7, the input voltage is divided and sampled by the resistors R22, R23, and the comparison reference voltage is generated by the R14 resistor and N4 (common to the small current diagnosis). The voltage diagnosis is that the comparator outputs a high voltage (close to VCC) when the power supply voltage is higher than a certain value (16V), and outputs a low voltage (close to 0V) when the auxiliary power supply is lower than a certain value (14V). This allows the condition of the auxiliary supply voltage to be diagnosed as a logic level signal output recognizable by the digital circuit.
In this embodiment, as shown in fig. 8, the logic and transistor open-circuit output circuit includes a diode D1, a diode D2, a photocoupler N7, an NPN transistor Q3, a resistor R27, a resistor R28, a resistor R29, and a resistor R30; the cathode of the diode D2 is connected with the output end of the proportional amplifying and small signal diagnosing circuit, and the anode of the diode D2 is connected with the anode of the diode D1; the cathode of the diode D1 is connected with a pin 1 of a photoelectric coupler N7, a pin 2 and a pin 3 of the photoelectric coupler N7 are both grounded, a pin 4 of the photoelectric coupler N7 is connected with an emitter of an NPN triode Q3 through a resistor R29, a pin 4 of the photoelectric coupler N7 is also connected with a base of the NPN triode Q3 through a resistor R30, and a collector of the NPN triode Q3 serves as an output KO;
one end of the resistor R28 is connected with the common end of the diode D1 and the pin 1 of the photoelectric coupler N7, and the other end of the resistor R28 is grounded; the resistor R27 is connected with the output end of the voltage diagnosis circuit;
when the voltages output by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit are both high level, the photoelectric coupler N7 works, so that the NPN triode Q3 is in saturated conduction; otherwise, the photoelectric coupler N7 does not work, the NPN triode Q3 does not work, and the NPN triode Q3 is in an open circuit state; thereby, the KO output is the auxiliary power supply voltage or the open circuit to realize the product comprehensive diagnosis function. Because the NPN triode is in a saturated conduction state when being conducted, the CE level of the triode has lower voltage drop, the output voltage of the collector is closer to the power voltage, and meanwhile, the driving capability is better.
Through the logic and triode open-circuit output circuit, the two paths of diagnosed signals realize the function of a hardware circuit and the gate through the simplest diode logic and, the product reliability is improved while the number of AND gate logic circuits is reduced, and the digital logic circuit has higher corresponding speed than the digital logic circuit in the prior art.
Through comprehensive diagnosis, the sensor can automatically shut off the onboard 28V power supply condition when the load current is abnormal (higher than a certain threshold value) and the power supply voltage is abnormal (lower than a certain threshold value), thereby achieving the purpose of protecting the load design and the power supply system. Compared with the traditional digital system diagnosis, the pure hardware circuit realizes the autonomous diagnosis circuit, has the advantages of quick response, simple circuit and structure, low cost, high reliability (anti-electromagnetic interference), no digital chip, no software and the like, and is very suitable for application in special industries.
The current sensor circuit is realized by adopting a logic circuit, and has strong anti-interference capability; thereby ensuring that the current sensor is very suitable for being applied in the fields of high environmental requirements, high precision and small volume and mass; the invention can be used for the linear detection of the direct current of the power distribution system, diagnoses the power supply and the power load of the sensor, provides the analog switching value signal output according to the diagnosed condition, and can quickly cut off the system power supply for protection and fault detection.
Example 2
As shown in fig. 9, the present embodiment is different from embodiment 1 in that the present embodiment provides a current sensor with comprehensive diagnostic function, which includes an outer casing 1, a current sensor circuit with comprehensive diagnostic function as described in embodiment 1 is disposed in the outer casing 1, and the current sensor circuit is in a multilayer board design; the shell body is made of aviation aluminum and has a shielding function. The lead adopts shielding, reliable grounding and the like, so that the product meets the requirements of CE102, CS101, CS114, CS115, CS116, RE102 and RS103 projects in GJB 151A. Has stronger capability of resisting electromagnetic interference.
Specifically, the size of the through-hole is 28mm by 8 mm; the length of the outer shell of the integral current sensor is 60mm, and the width of the outer shell of the integral current sensor is 43 mm; the current sensor has small volume and mass.
The current sensor is used for linear detection of direct current of a primary power distribution system, diagnoses the power supply condition and the power load condition of the current sensor, provides analog switching value signal output according to the diagnosed condition, and realizes rapid cut-off of the system power supply for protection and fault detection.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (9)
1. A current sensor circuit with a comprehensive diagnosis function is characterized by comprising a power supply circuit, a magnetoelectric conversion circuit, a proportional amplification output circuit, a proportional amplification and small signal diagnosis circuit, a voltage diagnosis circuit and a logic AND and triode open-circuit output circuit;
the power supply circuit is used for converting an onboard +28V auxiliary power supply into low voltage for each rear-stage module circuit to use;
the magnetoelectric conversion circuit is used for inputting a current signal to be measured from a through hole of the current sensor, generating a magnetic field according to the current periphery and electromagnetically converting the current signal to be measured to obtain a magnetic field signal; the magnetic gathering ring is used for gathering, the gathered magnetic field signal is sensed through a Hall device element, and the magnetic field signal is subjected to magnetoelectric conversion to obtain a processed electric signal;
the proportional amplification output circuit is used for carrying out secondary amplification processing on the processed electric signal to obtain a standard linear output signal; wherein, the small signal after the first-stage amplification processing is input to the proportional amplification and small signal diagnosis circuit;
the proportional amplification and small signal diagnosis circuit is used for acquiring the small signal after the primary amplification processing of the proportional amplification output circuit, further amplifying the small signal by adjustable amplification factor, comparing the processed small signal with a reference voltage through a hysteresis comparator and outputting the small signal;
the voltage diagnosis circuit is used for comparing the input voltage with a reference voltage and outputting the input voltage;
and the logic AND and triode open-circuit output circuit is used for logically AND-ing two paths of signals diagnosed by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit and outputting the two paths of signals through the triode open circuit.
2. The current sensor circuit with the comprehensive diagnosis function according to claim 1, wherein the power circuit comprises a fuse F1, a transient suppression diode F2, an NPN triode Q1, an adjustable reference N1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a capacitor C1 and a capacitor C2, one end of the fuse F1 is connected to an onboard +28V auxiliary power supply, the other end of the fuse F1 is connected to a resistor R1, the resistor R1 is connected to a pin 2 of the NPN triode Q1, a pin 1 of the NPN triode Q1 is connected to a pin 2 of the adjustable reference N1, and a pin 3 of the NPN triode Q1 is grounded;
one end of the transient suppression diode F2 is connected with the common end of the fuse F1 and the resistor R1, and the other end is grounded; one end of the capacitor C1 is connected with the common end of the pin 2 of the resistor R1 and the NPN triode Q1, the other end of the capacitor C1 is grounded, and the resistor R1 and the capacitor C1 form a first-order RC passive filter circuit;
one end of the resistor R2 is connected with a pin 2 of an NPN triode Q1, and the other end of the resistor R2 is connected with a pin 1 of an NPN triode Q1;
the resistor R3 and the resistor R4 are connected in series, and the capacitor C2 is connected in parallel with a first-order RC passive filter circuit consisting of the resistor R1 and the capacitor C1; the common ends of the resistor R3 and the resistor R4 are connected with a pin 1 of the adjustable reference N1; capacitor C2 has one end connected to VCC and the other end connected to ground.
3. The current sensor circuit with comprehensive diagnosis function according to claim 1, wherein the magnetoelectric conversion circuit comprises an adjustable reference N2 and a PNP triode Q2, a constant current source circuit consisting of the adjustable reference N2 and the PNP triode Q2 provides drive for the HG302 GaAs Hall element H1, and the temperature drift of the PN junction of the triode Q2 is used for compensating the unbalanced temperature drift of the H1 Hall bridge.
4. The current sensor circuit with integrated diagnostic function according to claim 1, wherein the proportional amplifying and small signal diagnostic circuit comprises an amplifier N5A and a hysteresis comparator N5B, a pin 3 of the amplifier N5A is connected to the small signal after the first-stage amplification processing of the proportional amplifying output circuit, a pin 2 of the amplifier N5A is connected to a pin 1 of the amplifier N5A through a resistor, a pin 1 of the amplifier N5A is connected to a pin 6 of the hysteresis comparator N5B, and a pin 5 of the hysteresis comparator N5B is connected to a reference voltage circuit through a resistor; pin 7 of the hysteresis comparator N5B serves as an output terminal and is connected to the input terminal of the and transistor open circuit output circuit.
5. The current sensor circuit with comprehensive diagnosis function of claim 1, wherein the open-circuit output circuit of the logical AND and triode comprises a diode D1, a diode D2, a photocoupler N7, an NPN triode Q3, a resistor R27, a resistor R28, a resistor R29 and a resistor R30; the cathode of the diode D2 is connected with the output end of the proportional amplifying and small signal diagnosing circuit, and the anode of the diode D2 is connected with the anode of the diode D1; the cathode of the diode D1 is connected with a pin 1 of a photoelectric coupler N7, a pin 2 and a pin 3 of the photoelectric coupler N7 are both grounded, a pin 4 of the photoelectric coupler N7 is connected with an emitter of an NPN triode Q3 through a resistor R29, a pin 4 of the photoelectric coupler N7 is also connected with a base of the NPN triode Q3 through a resistor R30, and a collector of the NPN triode Q3 serves as an output KO;
one end of the resistor R28 is connected with the common end of the diode D1 and the pin 1 of the photoelectric coupler N7, and the other end of the resistor R28 is grounded; the resistor R27 is connected with the output end of the voltage diagnosis circuit;
when the voltages output by the proportional amplification and small signal diagnosis circuit and the voltage diagnosis circuit are both high level, the photoelectric coupler N7 works to make the NPN triode Q3 conduct in a saturated mode; otherwise, the photoelectric coupler N7 does not work, the NPN triode Q3 does not work, and the NPN triode Q3 is in an open circuit state; thereby, the KO output is the auxiliary power supply voltage or the open circuit to realize the product comprehensive diagnosis function.
6. The current sensor circuit with integrated diagnostic function as claimed in claim 1, wherein said flux ring has a square structure; the magnetic core of the magnetic gathering ring is formed by stamping permalloy materials with high magnetic conductivity and low coercive force.
7. The current sensor circuit with integrated diagnostic function of claim 1, wherein said two-stage amplification process comprises a differential amplification process and an in-phase amplification process.
8. A current sensor with comprehensive diagnosis function, which is characterized by comprising an outer shell, wherein a current sensor circuit with comprehensive diagnosis function as claimed in any one of claims 1 to 7 is arranged in the outer shell, and the current sensor circuit is designed by adopting a multilayer board; the shell body is made of aviation aluminum and has a shielding function.
9. The current sensor with the comprehensive diagnosis function according to claim 8, wherein the current sensor is used for linear detection of direct current of a primary power distribution system, diagnoses power supply conditions and power load conditions of the current sensor, provides analog switch quantity signal output according to the diagnosed conditions, and realizes rapid cut-off of a system power supply for protection and fault detection.
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Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08113104A (en) * | 1994-10-18 | 1996-05-07 | Nec Home Electron Ltd | Detonating element igniting device |
| EP0748100A2 (en) * | 1995-06-06 | 1996-12-11 | Norscan Instruments, Ltd. | A cable monitoring system with multiple branch terminations |
| KR20050054449A (en) * | 2004-12-01 | 2005-06-10 | 주식회사 파워트론 | Battery cell voltage and impedance measuring circuit |
| CN101059548A (en) * | 2007-06-06 | 2007-10-24 | 常熟开关制造有限公司(原常熟开关厂） | Magnet coil break detection circuit |
| CN101478139A (en) * | 2009-01-22 | 2009-07-08 | 中国科学院等离子体物理研究所 | Multi-path large power velocity modulated valve overcurrent real-time protection apparatus having on-line self-detection function |
| CN101819228A (en) * | 2010-04-16 | 2010-09-01 | 上海交通大学 | Hall current sensor based current detection device |
| CN202471828U (en) * | 2012-03-13 | 2012-10-03 | 上海诺雅克电气有限公司 | Voltage sampling circuit suitable for dual-power automatic transfer switch and controller |
| CN103954910A (en) * | 2014-04-29 | 2014-07-30 | 国家电网公司 | Fault diagnosis device and method for current signals of permanent magnet operating mechanism |
| JP2016194483A (en) * | 2015-04-01 | 2016-11-17 | 富士電機機器制御株式会社 | Current detection device |
| CN208334493U (en) * | 2018-06-19 | 2019-01-04 | 合肥国轩高科动力能源有限公司 | Current acquisition circuit for battery management system of electric automobile |
| CN109450397A (en) * | 2018-12-09 | 2019-03-08 | 中国航空工业集团公司上海航空测控技术研究所 | A kind of difference magnetic power rotation speed sensor conditioning circuit |
| KR20200090562A (en) * | 2019-01-21 | 2020-07-29 | (주) 에코투모로우코리아 | Apparatus for wideband lossless partial discharge detection and noise suppression |
| CN111769843A (en) * | 2020-05-25 | 2020-10-13 | 南京璇玑信息技术有限公司 | Intelligent Internet of things software test information diagnosis circuit and repair method thereof |
-
2021
- 2021-08-25 CN CN202110980785.3A patent/CN113687134B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08113104A (en) * | 1994-10-18 | 1996-05-07 | Nec Home Electron Ltd | Detonating element igniting device |
| EP0748100A2 (en) * | 1995-06-06 | 1996-12-11 | Norscan Instruments, Ltd. | A cable monitoring system with multiple branch terminations |
| KR20050054449A (en) * | 2004-12-01 | 2005-06-10 | 주식회사 파워트론 | Battery cell voltage and impedance measuring circuit |
| CN101059548A (en) * | 2007-06-06 | 2007-10-24 | 常熟开关制造有限公司(原常熟开关厂） | Magnet coil break detection circuit |
| CN101478139A (en) * | 2009-01-22 | 2009-07-08 | 中国科学院等离子体物理研究所 | Multi-path large power velocity modulated valve overcurrent real-time protection apparatus having on-line self-detection function |
| CN101819228A (en) * | 2010-04-16 | 2010-09-01 | 上海交通大学 | Hall current sensor based current detection device |
| CN202471828U (en) * | 2012-03-13 | 2012-10-03 | 上海诺雅克电气有限公司 | Voltage sampling circuit suitable for dual-power automatic transfer switch and controller |
| CN103954910A (en) * | 2014-04-29 | 2014-07-30 | 国家电网公司 | Fault diagnosis device and method for current signals of permanent magnet operating mechanism |
| JP2016194483A (en) * | 2015-04-01 | 2016-11-17 | 富士電機機器制御株式会社 | Current detection device |
| CN208334493U (en) * | 2018-06-19 | 2019-01-04 | 合肥国轩高科动力能源有限公司 | Current acquisition circuit for battery management system of electric automobile |
| CN109450397A (en) * | 2018-12-09 | 2019-03-08 | 中国航空工业集团公司上海航空测控技术研究所 | A kind of difference magnetic power rotation speed sensor conditioning circuit |
| KR20200090562A (en) * | 2019-01-21 | 2020-07-29 | (주) 에코투모로우코리아 | Apparatus for wideband lossless partial discharge detection and noise suppression |
| CN111769843A (en) * | 2020-05-25 | 2020-10-13 | 南京璇玑信息技术有限公司 | Intelligent Internet of things software test information diagnosis circuit and repair method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 李星泽;杨影;: "电流检测电路中运算放大器与ADC的设计", 中国集成电路, no. 12 * |
| 谢涌;沈小军;陈金木;徐卫中;: "新型直流电源系统绝缘状态在线监测装置研制", 仪器仪表与分析监测, no. 01 * |
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