Fluxgate current sensor and signal conditioning method

Abstract

The invention provides a fluxgate current sensor and a signal adjusting method, and relates to the technical field of electronic power, the fluxgate current sensor comprises a direct current magnetic flux detection circuit, the direct current magnetic flux detection circuit comprises a self-oscillation circuit and a balance degaussing circuit, the self-oscillation circuit comprises a first coil, and the self-oscillation circuit detects direct current of a primary coil through the first coil; the balance degaussing circuit comprises a driving adjusting circuit and a second coil; one end of the driving adjusting circuit is connected with the self-excited oscillation circuit, the other end of the driving adjusting circuit is connected with the second coil, the driving adjusting circuit is used for processing excitation signals output by the self-excited oscillation circuit and adjusting first magnetic flux signals generated by the second coil, and the balance degaussing circuit is used for compensating second magnetic flux signals of the first coil through the first magnetic flux signals; the magnetic flux direction of the first magnetic flux signal is opposite to the magnetic flux direction of the second magnetic flux signal. And a magnetic flux signal generated by the second coil is adjusted through the driving adjusting circuit, so that better compensation is realized, and higher-precision and lower-noise current detection is achieved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of power electronics, and particularly relates to a magnetic flux gate current sensor and a signal adjusting method. BACKGROUND

[0002] The high-precision magnetic flux gate current sensor is generally used for instruments or high-precision detection, adopts the multi-magnetic ring closed-loop magnetic flux gate technology, and in the related technology, only when the performance of the magnetic cores of the first coil and the magnetic cores of the second coil is completely consistent, the magnetic flux generated by the two coils can be perfectly compensated in the closed loop, that is, the peak noise at the secondary coil, but in the actual current detection process, there is no coil magnetic core with completely consistent performance in the actual situation, and the compensation often has defects.

[0003] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0004] The present disclosure provides a magnetic flux gate current sensor and a signal adjusting method, which can at least solve the problem of incomplete compensation caused by the inconsistency between the single magnetic cores corresponding to the coils in the prior art, achieve better compensation, and achieve current detection with higher precision and lower noise.

[0005] Other characteristics and advantages of the present disclosure will become apparent from the following detailed description, or will be learned by practice of the present disclosure.

[0006] In a first aspect, the embodiments in the present disclosure provide a magnetic flux gate current sensor, comprising: a direct-current magnetic flux detection circuit, comprising a self-oscillation circuit and a balance demagnetization circuit; The self-oscillation circuit comprises a first coil, and the self-oscillation circuit detects the direct-current of the primary coil through the first coil; The balance demagnetization circuit comprises a driving adjustment circuit and a second coil; One end of the driving adjustment circuit is connected to the self-oscillation circuit, and the other end is connected to the second coil, for processing the excitation signal output by the self-oscillation circuit, and adjusting the first magnetic communication signal generated by the second coil according to the excitation signal; The balance demagnetization circuit is used for compensating the second magnetic communication signal of the first coil by the first magnetic communication signal generated by the second coil; the magnetic flux direction of the first magnetic communication signal is opposite to the magnetic flux direction of the second magnetic communication signal.

[0007] In a possible embodiment, the drive adjusting circuit comprises: a first amplitude adjusting circuit, configured to adjust the amplitude of the excitation signal generated by the second coil, and to adjust the first magnetic communication signal; and the drive adjusting circuit is connected to the same end of the second coil relative to the first coil. The first amplitude adjusting circuit comprises: an inverting amplifier; and the inverting input end of the inverting amplifier is connected to the self-oscillation circuit, and the output end is connected to the second coil; and at least one of the input resistance and the feedback resistance of the inverting amplifier is an adjustable resistance.

[0008] In a possible embodiment, the drive adjusting circuit comprises: a second amplitude adjusting circuit, configured to adjust the amplitude of the excitation signal generated by the second coil, and to adjust the first magnetic communication signal; and the drive adjusting circuit is connected to the opposite end of the second coil relative to the first coil. The second amplitude adjusting circuit comprises: an attenuation circuit and a first non-inverting amplifier; the attenuation circuit is connected to the self-oscillation circuit, and the output is connected to the non-inverting input end of the first non-inverting amplifier; The output end of the first non-inverting amplifier is connected to the second coil; and at least one of the ground resistance and the feedback resistance of the first non-inverting amplifier is an adjustable resistance. The adjustment coefficient of the attenuation circuit is less than or equal to 1; and the adjustment coefficient of the first non-inverting amplifier is greater than or equal to 1.

[0009] In a possible embodiment, the drive adjusting circuit comprises: a third amplitude adjusting circuit, configured to adjust the amplitude of the excitation signal generated by the second coil, and to adjust the first magnetic communication signal; and the drive adjusting circuit is connected to the opposite end of the second coil relative to the first coil. The third amplitude adjusting circuit comprises: an amplification circuit, an attenuation circuit, and an input control unit; The input control unit is connected to the self-oscillation circuit, and is configured to control the access of the amplification circuit and the attenuation circuit; The amplification circuit comprises: a second non-inverting amplifier; the non-inverting input end of the second non-inverting amplifier is connected to the input control unit; the output end of the second non-inverting amplifier is connected to the second coil; and at least one of the ground resistance and the feedback resistance of the second non-inverting amplifier is an adjustable resistance. The attenuation circuit comprises: a voltage dividing circuit and a voltage follower; one end of the voltage dividing circuit is connected to the input control unit, and the other end of the voltage dividing circuit is connected to the non-inverting input end of the voltage follower; and the output end of the voltage follower is connected to the second coil.

[0010] In a possible embodiment, the drive adjusting circuit comprises: a first edge shaping circuit; One end of the first edge shaping circuit is connected to the self-oscillation circuit, and the other end of the first edge shaping circuit is connected to the second coil, and the first edge shaping circuit is configured to adjust the edge change rate of the excitation signal generated by the second coil, and to adjust the first magnetic communication signal.

[0011] In a possible embodiment, the driving adjustment circuit comprises a fourth amplitude adjustment circuit and a second edge shaping circuit. One end of the fourth amplitude adjustment circuit is connected to the self-oscillation circuit, and the other end of the fourth amplitude adjustment circuit is connected to the second edge shaping circuit, for adjusting the amplitude of the excitation signal generated by the second coil and adjusting the first magnetic communication signal. The second edge shaping circuit is connected to the second coil, for adjusting the edge change rate of the excitation signal generated by the second coil and adjusting the first magnetic communication signal.

[0012] In a possible embodiment, the second edge shaping circuit comprises a first resistor; the greater the resistance of the first resistor, the smaller the edge change rate; and the first resistor is an adjustable resistor.

[0013] In a possible embodiment, the driving adjustment circuit further comprises an alternating magnetic flux detection circuit, the alternating magnetic flux detection circuit comprising a third coil, and the alternating magnetic flux detection circuit detecting the alternating current of the primary coil through the third coil.

[0014] In a possible embodiment, the driving adjustment circuit further comprises a coupling amplification closed loop circuit, the coupling amplification closed loop circuit comprising a comparison circuit, a current amplification circuit, and a secondary coil corresponding to the primary coil. The comparison circuit is connected to the self-oscillation circuit and the alternating magnetic flux detection circuit, for comparing and processing the signals input to the comparison circuit and transmitting to the input end of the current amplification circuit, and the output end of the current amplification circuit is connected to the secondary coil.

[0015] In a possible embodiment, the driving adjustment circuit further comprises a saturation self-recovery circuit; the saturation self-recovery circuit is used for detecting the saturation state of the primary coil, outputting a demagnetization signal, and the saturation self-recovery circuit is connected to the comparison circuit of the coupling amplification closed loop circuit, and the demagnetization signal is transmitted to the secondary coil to make the secondary coil generate a reverse magnetic flux and make the magnetic core of the primary coil demagnetize. The saturation self-recovery circuit comprises a frequency detection circuit, a signal output circuit, and a signal generation circuit. One end of the frequency detection circuit is connected to the self-oscillation circuit, for detecting the oscillation frequency value of the first coil. The signal output circuit comprises a first switch tube, a first optocoupler, a second optocoupler, a first protection diode, and a second protection diode; each optocoupler comprises a light-emitting diode and a phototriode. The gate of the first switch tube is connected to the frequency detection circuit, the source is grounded, and the drain is connected to a positive power supply; the light-emitting diodes in the first optocoupler and the second optocoupler are connected in parallel across the first switch tube. The signal generating circuit is connected to the emitter of the phototriode of the first optocoupler and the collector of the phototriode of the second optocoupler, respectively, the collector of the phototriode of the first optocoupler is connected to the first protection diode, and the emitter of the phototriode of the second optocoupler is connected to the second protection diode. When the frequency value is greater than the preset value, the first switch tube is turned off, the first optocoupler and the second optocoupler are turned on, and the waveform output by the signal generating circuit is output as a demagnetization signal through the protection diode.

[0016] In a possible embodiment, the saturation self-recovery circuit further comprises a saturation state indicating circuit; the saturation state indicating circuit comprises a second switch tube and an indicating lamp. The gate of the second switch tube is connected to the frequency detecting circuit, the source is connected to the indicating lamp, and the drain is grounded. When the frequency value is greater than the preset value, the second switch tube is turned off, the indicating lamp is turned off, and the secondary coil is in a saturation state.

[0017] In a second aspect, the embodiments of the present disclosure provide a signal adjusting method applied to a magnetic flux gate current sensor, comprising a self-oscillation circuit and a balance demagnetization circuit. The self-oscillation circuit comprises a first coil; the self-oscillation circuit detects the direct current of the primary coil through the first coil. The balance demagnetization circuit comprises a driving adjusting circuit and a second coil. One end of the driving adjusting circuit is connected to the self-oscillation circuit, the other end is connected to the second coil, and the driving adjusting circuit is used for processing the excitation signal output by the self-oscillation circuit and adjusting the first magnetic communication signal generated by the second coil according to the excitation signal. The balance demagnetization circuit is used for compensating the second magnetic communication signal of the first coil through the first magnetic communication signal generated by the second coil; the magnetic flux direction of the first magnetic communication signal is opposite to that of the second magnetic communication signal. The method comprises: Obtaining the second magnetic communication signal of the first coil; According to the second magnetic communication signal, the driving adjusting circuit is controlled to adjust the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted.

[0018] In a possible embodiment, the driving adjusting circuit comprises an amplitude adjusting circuit; the amplitude adjusting circuit is any one of a first amplitude adjusting circuit, a second amplitude adjusting circuit or a third amplitude adjusting circuit. According to the second magnetic communication signal, the driving adjusting circuit is controlled to adjust the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted, comprising: When the voltage effective value converted by the second magnetic communication signal is greater than the voltage effective value converted by the first magnetic communication signal generated by the second coil, the amplitude adjusting circuit is controlled to increase the voltage amplitude of the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted. detecting that a voltage effective value of the second magnetic communication signal transition is less than a voltage effective value of the first magnetic communication signal transition generated by the second coil, and controlling the amplitude adjustment circuit to reduce a voltage amplitude of the excitation signal generated by the second coil to adjust the first magnetic communication signal.

[0019] In a possible embodiment, the drive adjustment circuit comprises a first edge shaping circuit; controlling the drive adjustment circuit to adjust the excitation signal generated by the second coil according to the second magnetic communication signal to adjust the first magnetic communication signal, comprises: detecting that a voltage effective value of the second magnetic communication signal transition is greater than a voltage effective value of the first magnetic communication signal transition generated by the second coil, and controlling the first edge shaping circuit to increase an edge change rate of the excitation signal generated by the second coil to adjust the first magnetic communication signal; detecting that a voltage effective value of the second magnetic communication signal transition is less than a voltage effective value of the first magnetic communication signal transition generated by the second coil, and controlling the first edge shaping circuit to decrease an edge change rate of the excitation signal generated by the second coil to adjust the first magnetic communication signal.

[0020] In a possible embodiment, the drive adjustment circuit comprises a fourth amplitude adjustment circuit and a second edge shaping circuit; controlling the drive adjustment circuit to adjust the excitation signal generated by the second coil according to the second magnetic communication signal to adjust the first magnetic communication signal, comprises: detecting that a voltage effective value of the second magnetic communication signal transition is greater than a voltage effective value of the first magnetic communication signal transition generated by the second coil, and controlling the fourth amplitude adjustment circuit to increase a voltage amplitude of the excitation signal generated by the second coil, and / or, controlling the second edge shaping circuit to adjust to increase an edge change rate of the excitation signal generated by the second coil to adjust the first magnetic communication signal; detecting that a voltage effective value of the second magnetic communication signal transition is less than a voltage effective value of the first magnetic communication signal transition generated by the second coil, and controlling the fourth amplitude adjustment circuit to decrease a voltage amplitude of the excitation signal generated by the second coil, and / or, controlling the second edge shaping circuit to adjust to decrease an edge change rate of the excitation signal generated by the second coil to adjust the first magnetic communication signal.

[0021] In a third aspect, an embodiment of the present disclosure provides a signal adjustment device, comprising: an acquisition unit configured to acquire a second magnetic communication signal of a first coil; an adjustment unit configured to control a drive adjustment circuit to adjust an excitation signal generated by a second coil according to the second magnetic communication signal to adjust a first magnetic communication signal.

[0022] In a fourth aspect, an electronic device is provided, including: a processor; and a memory storing executable instructions of the processor; wherein the processor is configured to execute the method in the second aspect above via execution of the executable instructions.

[0023] In a fifth aspect, a computer-readable storage medium is provided, having stored thereon a computer program, the computer program being executed by a processor to implement the method in the second aspect above.

[0024] In a sixth aspect, according to another aspect of the present disclosure, a computer program product or computer program is also provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to cause the computer device to perform the method in the second aspect above.

[0025] The magnetic flux gate current sensor and signal adjusting method provided by the embodiments of the present disclosure relate to the technical field of electronic power, and include: a direct-current magnetic flux detection circuit including a self-oscillation circuit and a balance demagnetization circuit, the self-oscillation circuit including: a first coil, the self-oscillation circuit detecting a direct-current of a primary coil through the first coil; the balance demagnetization circuit including: a driving adjusting circuit and a second coil; one end of the driving adjusting circuit being connected to the self-oscillation circuit, and the other end of the driving adjusting circuit being connected to the second coil, the driving adjusting circuit being configured to process a magnetizing signal output by the self-oscillation circuit, and adjust a first magnetic communication signal generated by the second coil according to the magnetizing signal, the balance demagnetization circuit being configured to compensate a second magnetic communication signal of the first coil through the first magnetic communication signal generated by the second coil; and the magnetic flux direction of the first magnetic communication signal being opposite to the magnetic flux direction of the second magnetic communication signal. The magnetic communication signal generated by the second coil is adjusted through the driving adjusting circuit, better compensation is achieved, and higher-precision and lower-noise current detection is achieved.

[0026] It should be understood that the general description above and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0027] The drawings incorporated into the specification and forming a part thereof illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0028] Figure 1 A schematic diagram showing the winding of a magnetic flux gate current sensor in an embodiment of the present disclosure is shown; Figure 2Fig. 1 shows a structure diagram of a magnetic flux gate current sensor according to an embodiment of the present disclosure; Figure 3 Fig. 2 shows a circuit structure diagram of a self-oscillation circuit according to an embodiment of the present disclosure; Figure 4 Fig. 3 shows a structure diagram of a drive adjustment circuit according to an embodiment of the present disclosure; Figure 5 Fig. 4 shows a circuit structure diagram of a positive and negative power supply according to an embodiment of the present disclosure; Figure 6 Fig. 5 shows another structure diagram of a drive adjustment circuit according to an embodiment of the present disclosure; Figure 7 Fig. 6 shows a third structure diagram of a drive adjustment circuit according to an embodiment of the present disclosure; Figure 8 Fig. 7 shows a fourth structure diagram of a drive adjustment circuit according to an embodiment of the present disclosure; Figure 9 Fig. 8 shows a structure diagram of another magnetic flux gate current sensor according to an embodiment of the present disclosure; Figure 10 Fig. 9 shows a structure diagram of a saturated self-recovery circuit according to an embodiment of the present disclosure; Figure 11 Fig. 10 shows a structure diagram of a saturated state indicating circuit according to an embodiment of the present disclosure; Figure 12 Fig. 11 shows a structure diagram of an alternating current magnetic flux detection circuit according to an embodiment of the present disclosure; Figure 13 Fig. 12 shows a flow chart of a signal adjustment method according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art. Features described in the description, examples, or claims that are unified under a single header are not necessarily mutually exclusive of one another. The various features described or shown in the specification can be each combined in any combination. Described features may

[0030] In addition, the accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0031] First, the magnetic core and the coil in the magnetic flux gate current sensor in the embodiment of the present disclosure are described, Figure 1 A schematic diagram of a magnetic flux gate current sensor in the embodiment of the present disclosure is shown, as Figure 1 As shown, it comprises a first magnetic core C1, a second magnetic core C2 and a third magnetic core C3 coaxially stacked together to form an overall magnetic core, wherein the first magnetic core C1, the second magnetic core C2 and the third magnetic core C3 are respectively wound with a first coil L1, a second coil L2 and a third coil L3, the overall magnetic core is wound with a primary coil Lp and a secondary coil Ls, the primary coil Lp receives an externally input measured direct current or measured alternating current Ip, and the output end of the secondary coil Ls outputs a measured direct current or alternating current Is.

[0032] In the related art, only when the performances of the first magnetic core C1 and the second magnetic core C2 are completely consistent, the magnetic flux generated by the two coils can achieve perfect compensation in a closed loop, i.e., the peak noise at the secondary coil Ls, but in the actual current detection process, there is no magnetic core with completely consistent performance in the actual situation, and the compensation often has defects.

[0033] The implementation of the example of the present disclosure will be described in detail below in combination with the drawings and embodiments.

[0034] Figure 2 A structural schematic diagram of a magnetic flux gate current sensor in the embodiment of the present disclosure is shown, as Figure 2 As shown, the magnetic flux gate current sensor 2000 comprises a direct-current magnetic flux detection circuit 2100, and the direct-current magnetic flux detection circuit 2100 comprises a self-oscillation circuit 2110 and a balance demagnetization circuit 2120.

[0035] The self-oscillation circuit 2110 comprises a first coil L1, and the self-oscillation circuit 2110 detects the direct current of the primary coil through the first coil L1, the balance demagnetization circuit 2120 comprises a driving adjustment circuit 2121 and a second coil L2, and is used for compensating the magnetic flux of the first coil L1 through the second coil L2; one end of the driving adjustment circuit 2121 is connected to the self-oscillation circuit 2110, and the other end is connected to the second coil, which is used for processing the excitation signal output by the self-oscillation circuit 2110, and adjusting the first magnetic communication signal generated by the second coil L2 according to the excitation signal, so that the balance demagnetization circuit realizes the function of compensating the second magnetic communication signal of the first coil through the first magnetic communication signal generated by the second coil, and the magnetic flux direction of the first magnetic communication signal is opposite to that of the second magnetic communication signal.

[0036] Through the scheme in the embodiment of the disclosure, the first magnetic communication signal generated by the second coil L2 is dynamically adjusted in real time by the driving adjustment circuit 2121 according to the second magnetic communication signal of the first coil, the second magnetic communication signal generated by the first coil L1 is better compensated, the incomplete compensation caused by the inconsistency difference of the magnetic core monomer is broken through, better compensation is realized, the magnetic core works in a more stable state, the magnetic flux balance during auxiliary direct current or alternating current detection is assisted, higher precision and lower noise current detection is achieved, and the current detection in the embodiment of the disclosure can achieve a precision of ten thousandths.

[0037] Figure 3 A circuit structure diagram of a self-oscillation circuit in the embodiment of the disclosure is shown. Figure 3 As shown in the figure, the self-oscillation circuit 2110 includes: a first coil L1, a transient voltage suppressor (TVS) diode TVS1, a resistor R1, a capacitor C1, an operational amplifier U1A, resistors R2, R3, R4, R5 and R6, a diode D1 and a diode D2.

[0038] Among them, the transient voltage suppressor diode TVS1 is connected in parallel across the first coil L1, the black origin on the lower side of the first coil L1 is the dotted end, Figure 1 and the dotted end of the first coil L1, the second coil L2 and other coils in the subsequent figures represents that the coils are homonymous ends to each other, the dotted end of the first coil L1 is the port of the first coil L1 connected to the self-oscillation circuit, the non-dotted end of the first coil L1 is connected to the resistor R1, the other end of the resistor R1 is grounded, the dotted end of the first coil L1 is connected to the capacitor C1, and the other end of the capacitor C1 is grounded.

[0039] The resistors R4, R5 and R6 are connected in parallel, and one end of the resistor network formed after being connected in parallel is connected to the output end of the operational amplifier U1A, the other end is connected to the dotted end of the first coil L1, the non-inverting input end of the operational amplifier U1A is connected to the resistor R2 and the resistor R3, the other end of R2 is grounded, the other end of R3 is connected to the dotted end of the first coil L1, and the inverting input end of the operational amplifier U1A is connected to the non-dotted end of the first coil L1.

[0040] The diode D1 and the diode D2 form a diode network that is reverse to each other and connected in parallel, one end of the diode network is connected to the dotted end of the first coil L1, and the other end is grounded.

[0041] Among them, the circuit structure of the resistors R4, R5 and R6 connected in parallel plays a role of current limiting and impedance limiting in the self-oscillation circuit 2110.

[0042] Figure 3The circuit structure in the first magnetic communication signal detection circuit includes three parts of outputs, namely, Dout, Fout1 and Fout2, Dout is a signal for detecting the first coil L1, Fout1 is a signal for detecting the frequency of the primary coil Lp, and Fout2 is an excitation signal.

[0043] In a possible embodiment, the adjustment of the second coil L2 by the drive adjustment circuit 2121 can include various modes, which are not specifically limited in the embodiments of the present disclosure, and are described below.

[0044] Embodiment 1: The drive adjustment circuit 2121 can include a first amplitude adjustment circuit, which is configured to adjust the amplitude of the excitation signal generated by the second coil L2, and adjust the first magnetic communication signal.

[0045] Further, the drive adjustment circuit is connected to the same end of the second coil relative to the first coil, and the first amplitude adjustment circuit can be an inverting amplifier; the inverting input end of the inverting amplifier is connected to the self-oscillation circuit 2110, and the output end is connected to the second coil L2; at least one of the input resistance and the feedback resistance of the inverting amplifier is an adjustable resistance; by adjusting the resistance values of the input resistance and the feedback resistance, the excitation signal is processed, the amplitude of the excitation signal is adjusted, and the peak value, the effective value and the like of the first magnetic communication signal are adjusted. A circuit structure in which the magnetic flux of the second coil L2 and the first coil L1 is reversed, and the first magnetic communication signal of the second coil L2 is dynamically adjusted in real time, achieves a better compensation effect.

[0046] In a possible embodiment, the setting of the adjustable resistance can include various modes, which are not specifically limited in the embodiments of the present disclosure, for example, the input resistance can be set as an adjustable resistance, the feedback resistance can be set as an adjustable resistance, a parallel adjustable resistance can be connected to the input resistance with a fixed resistance value, and the input resistance as a whole can be formed as an adjustable resistance, or a parallel adjustable resistance can be connected to the feedback resistance with a fixed resistance value, and the feedback resistance as a whole can be formed as an adjustable resistance.

[0047] In a possible embodiment, the operational amplifier is further connected to a positive power supply and a negative power supply, and a necessary working voltage range is provided; a capacitor is connected between the positive power supply and the negative power supply, and is configured to filter high-frequency noise and transient interference from the power supply.

[0048] In a possible embodiment, in order to balance the input bias current, reduce the DC output error, and improve the precision, the inverting amplifier can further include a grounding resistance.

[0049] In a possible embodiment, a transient voltage suppressor diode can be connected in parallel across the second coil L2, and functions to protect the circuit and clamp the voltage; one end of the second coil L2 is connected to the inverting amplifier, and the other end can be grounded through a resistance.

[0050] Figure 4 A structure diagram of a driving adjustment circuit in an embodiment of the present disclosure is shown in FIG. 2. Figure 4 As shown in FIG. 2, the driving adjustment circuit 2121 comprises a first amplitude adjustment circuit 410.

[0051] The first amplitude adjustment circuit 410 is an inverting amplifier. The inverting amplifier comprises an input resistor R7, a feedback resistor R8, a grounding resistor R9, and an operational amplifier U2A. The driving adjustment circuit 2121 further comprises a resistor R10 and a transient voltage suppressor diode TVS2.

[0052] The operational amplifier U2A is connected to a positive power supply Vcc and a negative power supply Vee. The inverting input terminal of the operational amplifier U2A is connected to the excitation signal and is connected to the self-oscillation circuit 2110. The output terminal of the operational amplifier U2A is connected to the taping end of the second coil L2. The transient voltage suppressor diode TVS2 is connected in parallel to the two ends of the second coil L2. The non-taping end of the second coil L2 is connected to the resistor R10, and the other end of the resistor R10 is grounded. Figure 4 The black dot on the upper side of the second coil L2 in FIG. 2 indicates the taping end of the second coil L2.

[0053] The input of the input resistor R7 is the excitation signal and is connected to the inverting input terminal of the operational amplifier U2A. One end of the feedback resistor R8 is connected to the inverting input terminal of the operational amplifier U2A, and the connection point is between the inverting input terminal of the operational amplifier U2A and the input resistor R7. The other end of the feedback resistor R8 is connected to the output terminal of the operational amplifier U2A, and the connection point is between the output terminal of the operational amplifier U2A and the second coil L2. The grounding resistor R9 is connected to the non-inverting input terminal of the operational amplifier U2A, and the other end is grounded.

[0054] Taking the input resistor R7 as a fixed resistance and the feedback resistor R8 as an adjustable resistance as an example.

[0055] In the initial stage, the resistance of the feedback resistor R8 can be set to be the same as the input resistor R7. The resistance of the feedback resistor R8 is adjusted to change the gain of the inverting amplifier 211, thereby adjusting the first magnetic communication signal of the second coil L2, following the change of the detected second magnetic communication signal of the first coil L1.

[0056] Figure 4 The taping end of the second coil L2 in FIG. 2 and the taping end of the first coil L1 in FIG. 1 are homonymous terminals. Figure 2 The taping end of the second coil L2 in FIG. 2 and the taping end of the first coil L1 in FIG. 1 are homonymous terminals.

[0057] The purpose of the scheme is to enable the second coil to better compensate for the first coil, so that the magnetic flux generated by the two coils should be opposite, and better magnetic flux offset is achieved on the basis of the magnetic flux being opposite. By adjusting the gain, when the effective value of the voltage corresponding to the first magnetic communication signal of the second coil L2 is slightly smaller than the effective value of the voltage corresponding to the second magnetic communication signal of the first coil L1, the output voltage of the operational amplifier U2A is slightly larger, the amplitude of the excitation signal of the second coil L2 is increased, and better compensation effect is achieved; when the effective value of the voltage corresponding to the first magnetic communication signal of the second coil L2 is slightly larger than the effective value of the voltage corresponding to the second magnetic communication signal of the first coil L1, the output voltage of the operational amplifier U2A is slightly smaller, the amplitude of the excitation signal of the second coil L2 is reduced, and better compensation effect is achieved.

[0058] The positive power supply Vcc and the negative power supply Vee connected with the operational amplifier U1A and the operational amplifier U2A can be the same, Figure 5 A circuit structure diagram of a positive and negative power supply in the embodiment of the present disclosure is shown in FIG. 6. Figure 5 As shown in FIG. 6, the positive power supply Vcc and the negative power supply Vee include a capacitor C2 therebetween, which is used to filter high-frequency noise and transient interference on the power line, prevent power fluctuation from affecting the normal operation of the operational amplifier, and avoid self-oscillation of the circuit through the power line.

[0059] Embodiment 2 The driving adjustment circuit 2121 can include a second amplitude adjustment circuit for adjusting the amplitude of the excitation signal generated by the second coil L2 and adjusting the first magnetic communication signal. The driving adjustment circuit is connected to the opposite-phase end of the second coil relative to the first coil. The second amplitude adjustment circuit includes an attenuation circuit and a first non-inverting amplifier. The attenuation circuit is connected to the self-oscillation circuit 2110, and the output is connected to the non-inverting input end of the first non-inverting amplifier. The output end of the first non-inverting amplifier is connected to the second coil L2. At least one of the ground resistance and the feedback resistance of the first non-inverting amplifier is an adjustable resistance. The adjustment coefficient of the attenuation circuit is less than or equal to 1. The adjustment coefficient of the first non-inverting amplifier is greater than or equal to 1.

[0060] Figure 6 A second structure diagram of a driving adjustment circuit in the embodiment of the present disclosure is shown in FIG. 7. Figure 6 As shown in FIG. 7, the driving adjustment circuit 2121 includes a second amplitude adjustment circuit 610.

[0061] The second amplitude adjusting circuit 610 comprises an attenuation circuit 611 and a first non-inverting amplifier 612. The attenuation circuit 611 can comprise an adjustable potentiometer RP and a resistor R100. The attenuation circuit 611 is used to process the excitation signal so as to reduce the amplitude of the excitation signal of the second coil L2, thereby obtaining the first magnetic communication signal. The first non-inverting amplifier 612 is used to process the excitation signal so as to increase the amplitude of the excitation signal of the second coil L2, thereby obtaining the first magnetic communication signal. The attenuation circuit 611 and the first non-inverting amplifier 612 cooperate so that the driving adjusting circuit can realize the function of adjusting the amplitude of the first magnetic communication signal generated by the second coil according to the excitation signal.

[0062] The first non-inverting amplifier 612 comprises an operational amplifier U3A, a grounding resistor R11 and a feedback resistor R12. The feedback resistor R12 is an adjustable resistor. For details, please refer to the above description. The driving adjusting circuit 2121 further comprises a resistor R13 and a transient voltage suppressor diode TVS3.

[0063] The one end of the potentiometer RP is connected to the self-oscillation circuit 2110, and the input is the excitation signal. The other end of the potentiometer RP is connected to the non-inverting input terminal of the operational amplifier U3A. When the potentiometer RP is adjusted to the uppermost end of the potentiometer RP, the input is 0, and the excitation signal is not attenuated. When the potentiometer RP is adjusted to the uppermost end of the potentiometer RP and then adjusted downward, the excitation signal is attenuated, and the input voltage input to the operational amplifier U3A is reduced. The one end of the resistor R100 is connected to the other end of the potentiometer RP, and the other end of the resistor R100 is grounded. Figure 6 Figure 6 The one end of the potentiometer RP is connected to the self-oscillation circuit 2110, and the input is the excitation signal. The other end of the potentiometer RP is connected to the non-inverting input terminal of the operational amplifier U3A. When the potentiometer RP is adjusted to the uppermost end of the potentiometer RP, the input is 0, and the excitation signal is not attenuated. When the potentiometer RP is adjusted to the uppermost end of the potentiometer RP and then adjusted downward, the excitation signal is attenuated, and the input voltage input to the operational amplifier U3A is reduced. The one end of the resistor R100 is connected to the other end of the potentiometer RP, and the other end of the resistor R100 is grounded.

[0064] The inverting input terminal of the operational amplifier U3A is connected to the feedback resistor R12 and the grounding resistor R11. The other end of the grounding resistor R11 is grounded. The other end of the feedback resistor R12 is connected to the output terminal of the operational amplifier U3A. The feedback resistor R12 is connected between the grounding resistor R11 and the inverting input terminal of the operational amplifier U3A. The operational amplifier U3A is connected to the positive power supply Vcc and the negative power supply Vee.

[0065] The non-tapped end of the second coil L2 is connected to the output terminal of the operational amplifier U3A. The two ends of the second coil L2 are connected in parallel to the transient voltage suppressor diode TVS3. The tapped end of the second coil L2 is connected to the resistor R13, and the other end of the resistor R13 is grounded. Figure 6 The black dot on the upper side of the second coil L2 represents the tapped end of the second coil L2.

[0066] The driving adjusting circuit 2121 can realize the function of adjusting the amplitude of the first magnetic communication signal generated by the second coil according to the excitation signal. Figure 6 ​The circuit structure in the drive adjustment circuit 2121 can adjust the increase or decrease of the amplitude of the excitation signal of the second coil. The embodiment of the present disclosure takes the example that the drive adjustment circuit is connected to the opposite-phase end of the second coil relative to the first coil. The dotted end of the second coil L2 is the same-phase end as the dotted end of the first coil L1. A schematic circuit structure of the drive adjustment circuit 2121 is provided.

[0067] Embodiment 3 The drive adjustment circuit 2121 can include two circuit structures to realize the adjustment mode of the increase or decrease of the amplitude of the excitation signal of the second coil. The embodiment of the present disclosure takes the example that the drive adjustment circuit is connected to the opposite-phase end of the second coil relative to the first coil. The dotted end of the second coil L2 is the same-phase end as the dotted end of the first coil L1. A schematic circuit structure of the drive adjustment circuit 2121 is provided.

[0068] The drive adjustment circuit 2121 can include: a third amplitude adjustment circuit, configured to adjust the amplitude of the excitation signal generated by the second coil, so as to adjust the first magnetic communication signal; and the drive adjustment circuit is connected to the opposite-phase end of the second coil relative to the first coil.

[0069] The third amplitude adjustment circuit includes: an amplitude increasing circuit, an amplitude decreasing circuit, and an input control unit connected to the self-oscillating circuit 2110, configured to control the access of the amplitude increasing circuit and the amplitude decreasing circuit. The amplitude decreasing circuit includes: a voltage dividing circuit and a voltage follower.

[0070] Exemplarily, the amplitude increasing circuit is a second non-inverting amplifier; the non-inverting input end of the second non-inverting amplifier is connected to the input control unit; the output end of the second non-inverting amplifier is connected to the second coil L2; at least one of the ground resistance and the feedback resistance of the second non-inverting amplifier is an adjustable resistance; one end of the voltage dividing circuit is connected to the input control unit, and the other end of the voltage dividing circuit is connected to the non-inverting input end of the voltage follower; and the output end of the voltage follower is connected to the second coil.

[0071] Figure 7 A structure schematic diagram three of a drive adjustment circuit in the embodiment of the present disclosure is shown as follows. Figure 7 As shown in the structure schematic diagram three, the drive adjustment circuit 2121 includes: a third amplitude adjustment circuit 710, and the third amplitude adjustment circuit 710 includes: an amplitude increasing circuit 711, an amplitude decreasing circuit 712, and an input control unit 713.

[0072] The input control unit 713 is connected to the self-oscillation circuit 2110, and the input is the excitation signal. When it is necessary to increase the amplitude of the excitation signal of the second coil L2, the excitation signal is connected to the amplitude increasing circuit 711. When it is necessary to decrease the amplitude of the excitation signal of the second coil L2, the excitation signal is connected to the amplitude decreasing circuit 712.

[0073] The amplitude decreasing circuit 712 includes a voltage dividing circuit 714 and a voltage follower 715. The voltage dividing circuit 714 can include an adjustable resistor R14 and a resistor R15. The voltage follower 715 is a voltage follower, which includes an operational amplifier U4A. The connection mode is the same as that of the voltage follower, and will not be described again.

[0074] One end of the adjustable resistor R14 is connected to the input control unit 713, and the other end of the adjustable resistor R14 is connected to the non-inverting input terminal of the operational amplifier U4A. One end of the resistor R15 is connected to the non-inverting input terminal of the operational amplifier U4A, and the other end of the resistor R15 is grounded. The non-inverting input terminal of the operational amplifier U4A is connected between the adjustable resistor R14 and the resistor R15.

[0075] The output terminal of the operational amplifier U4A is connected to the non-dot end of the second coil L2. The two ends of the second coil L2 are connected in parallel to a transient voltage suppressor diode TVS4. The dot end of the second coil L2 is connected to a resistor R16, and the other end of the resistor R16 is grounded. Figure 7 The black dot on the upper side of the second coil L2 represents the dot end of the second coil L2.

[0076] The amplitude increasing circuit 711 is a non-inverting amplifier, which includes a grounded resistor R17, an operational amplifier U5A, and a feedback resistor R18. The feedback resistor R18 is an adjustable resistor. The connection mode is the same as that of the non-inverting amplifier, and will not be described again. The output terminal of the operational amplifier U5A is connected to the non-dot end of the second coil L2.

[0077] In a possible embodiment, the drive adjusting circuit 2121 can further include a first edge shaping circuit. One end of the first edge shaping circuit is connected to the self-oscillation circuit 2110, and the other end of the first edge shaping circuit is connected to the second coil L2. The first edge shaping circuit is used to adjust the edge change rate of the excitation signal generated by the second coil L2, and adjust the first magnetic communication signal.

[0078] For example, the first edge shaping circuit can include an adjustable resistor connected in series with the second coil L2, forming an RL resonance circuit. By adjusting the resistance value of the resistor, the edge change rate of the excitation signal of the second coil L2 is slowed down.

[0079] For example, the first edge shaping circuit can include a fast driving device, which can be used to speed up the edge change rate of the excitation signal of the second coil L2.

[0080] For example, the first edge shaping circuit can include a capacitor connected in parallel to the second coil L2, forming an LC resonant circuit, and by adjusting the value of the capacitor, the edge change rate of the excitation signal of the second coil L2 is accelerated.

[0081] The above examples can be combined to adjust the edge change rate of the excitation signal of the second coil L2, so that the magnetic flux of the second coil L2 better compensates for the magnetic flux of the first coil L1, thereby improving the accuracy of the measured current.

[0082] Embodiment 4: The drive adjustment circuit 2121 can further include a fourth amplitude adjustment circuit and a second edge shaping circuit, and the drive adjustment circuit 2121 can simultaneously adjust the amplitude and the edge change rate of the excitation signal of the second coil L2.

[0083] The second edge shaping circuit can include a first resistor, and the greater the resistance value of the first resistor, the smaller the edge change rate of the excitation signal, and the first resistor is an adjustable resistor.

[0084] The circuit structure of the fourth amplitude adjustment circuit can refer to the first amplitude adjustment circuit, the second amplitude adjustment circuit, and the third amplitude adjustment circuit in the above examples, and the circuit structure of the first amplitude adjustment circuit is taken as an example of the fourth amplitude adjustment circuit, and the second edge shaping circuit includes a first resistor as an example. The circuit structure of the drive adjustment circuit 2121 in the embodiment of the present disclosure is described.

[0085] Figure 8 A fourth structural diagram of a drive adjustment circuit in the embodiment of the present disclosure is shown. Figure 8 As shown in the fourth structural diagram of the drive adjustment circuit, the drive adjustment circuit 2121 includes a fourth amplitude adjustment circuit 810 and a second edge shaping circuit 811.

[0086] The fourth amplitude adjustment circuit 810 is an inverting amplifier, and the inverting amplifier includes a grounding resistor R19, an input resistor R20, a feedback resistor R21, and an operational amplifier U6A. The second edge shaping circuit 811 can be the circuit structure of the first edge shaping circuit, Figure 8 for example, including a resistor R22.

[0087] The drive adjustment circuit 2121 further includes a transient voltage suppressor diode TVS5 and a resistor R23.

[0088] The circuit structure of the fourth amplitude adjustment circuit 810 is similar to that of the first amplitude adjustment circuit, and the similarities of other circuit structures are not described again.

[0089] The output end of the operational amplifier U6A is connected to one end of the resistor R22, the other end of the resistor R22 is connected to the end with a dot of the second coil L2, and the feedback resistor R21 is connected between the resistor R22 and the end with a dot of the second coil L2.

[0090] Through the above circuit structure, by controlling the output voltage of the output end of the operational amplifier U6A, the excitation input to the second coil L2 is further increased or reduced, the amplitude of the excitation signal of the second coil L2 is regulated, the rising edge change rate of the excitation signal of the second coil L2 can be slowed down based on the adjusting resistor R22, the change rate of the magnetic flux curve corresponding to the first magnetic communication signal is slower than the change rate of the magnetic flux curve corresponding to the second magnetic communication signal of the first coil L1, and the size of the slowed down edge change rate is adjusted by adjusting the resistance value of the resistor R22. It should be noted that the resistor R22 in the embodiment of the present disclosure functions to change the voltage edge change rate, and the inductance current change rate will not be changed after the voltage is stabilized.

[0091] In a possible embodiment, the magnetic flux gate current sensor 2000 further includes an alternating current magnetic flux detection circuit, the alternating current magnetic flux detection circuit includes a third coil, the alternating current magnetic flux detection circuit detects the alternating current of the primary coil through the third coil, and the alternating current magnetic flux detection circuit detects the alternating current of the primary coil by using the mutual inductance principle.

[0092] In a possible embodiment, the magnetic flux gate current sensor 2000 further includes a coupling amplification closed loop circuit, the coupling amplification closed loop circuit includes a comparison circuit, a current amplification circuit, and a secondary coil Ls of the primary coil Lp.

[0093] The comparison circuit is connected to the self-oscillation circuit 2110 and the alternating current magnetic flux detection circuit, is used for comparing and processing the signals input to the comparison circuit, and transmits to the input end of the current amplification circuit, the output end of the current amplification circuit is connected to the secondary coil, and the current amplification circuit is used for amplifying the signals input by the comparison circuit.

[0094] The comparison circuit can be a comparison circuit composed of an operational amplifier as the main body, and the current amplification circuit can be a totem pole circuit, and the specific circuit structure is not limited in the embodiment of the present disclosure.

[0095] The comparison circuit is connected to Dout in Figure 3 , the input is the signal detected to the direct current component, when the input is the signal detected to the direct current component, the output of the comparison circuit is the signal corresponding to the signal of the direct current component after the signal is processed by the operational amplifier, and when the comparison circuit detects the signal of the alternating current component, the output of the comparison circuit is the signal corresponding to the signal of the alternating current component after the signal is processed by the operational amplifier.

[0096] In a possible embodiment, the fluxgate current sensor further comprises a saturation self-recovery circuit configured to demagnetize the primary coil Lp in the saturation state.

[0097] The saturation self-recovery circuit is configured to detect the saturation state of the primary coil Lp, output a demagnetization signal, and be connected to the coupling and amplification closed loop circuit to transmit the demagnetization signal to the secondary coil Ls, so that the secondary coil Ls generates a reverse magnetic flux to demagnetize the magnetic core of the primary coil Lp. The magnetic core of the primary coil Lp is a whole magnetic core.

[0098] The saturation self-recovery circuit comprises a frequency detection circuit, a signal output circuit, and a signal generation circuit. The frequency detection circuit is connected to Fout1 in Figure 2 .

[0099] Figure 9 Another structure of a fluxgate current sensor in the embodiment of the present disclosure is shown in a structure diagram, as shown in FIG. 10, comprising a direct-current magnetic flux detection circuit 2100, an alternating-current magnetic flux detection circuit 910, a coupling and amplification closed loop circuit 920, and a saturation self-recovery circuit 930. Figure 9

[0100] The direct-current magnetic flux detection circuit 2100 comprises a self-oscillation circuit 2110 and a balance demagnetization circuit 2120.

[0101] The self-oscillation circuit 2110 comprises a first coil L1, and the balance demagnetization circuit 2120 comprises a driving and adjusting circuit 2121 and a second coil L2.

[0102] The alternating-current magnetic flux detection circuit 910 comprises a third coil L3.

[0103] The coupling and amplification closed loop circuit 920 comprises a comparison circuit 921, a current amplification circuit 922, and a secondary coil Ls.

[0104] The saturation self-recovery circuit 930 comprises a frequency detection circuit 931, a signal output circuit 932, and a signal generation circuit 933. The signal output circuit 932 is connected to the comparison circuit 921, and the output demagnetization signal is received and processed by the comparison circuit 921.

[0105] In the coupling and amplification closed loop circuit 920, the current flowing into one end of the secondary coil Ls is the same-named end of the secondary coil Ls relative to the first coil L1. The coupling and amplification closed loop circuit 920 can further comprise a protection circuit connected to the secondary coil Ls, and the embodiment of the present disclosure will not be described again.

[0106] ​It should be noted that the direct current detection part of the fluxgate current sensor in the embodiments of the present disclosure is: the self-oscillation circuit 2110 is used to bidirectionally excite the first coil L1, an equivalent open-loop fluxgate excitation circuit is constructed, the first coil L1 winding is bidirectionally excited, the direct current component in the current in the primary coil Lp is detected according to the fluxgate effect, and the magnetic flux change caused by the direct current is converted into a detectable electrical signal on the secondary coil Ls.

[0107] The alternating current magnetic flux detection part is: relying on the third coil L3 and the mutual inductance principle, the alternating current in the secondary coil generates a changing magnetic flux, the third coil L3 is coupled by mutual inductance, and the coupled signal is coupled to the closed-loop magnetic flux compensation part, the alternating current magnetic flux on the secondary coil Ls is converted into a measurable electrical signal, and the alternating current component in the primary coil Lp is detected.

[0108] The balanced demagnetization part is: the self-oscillation circuit 2110 is used to bidirectionally excite the second coil L2, and the second coil generates an opposite magnetic signal, and the first magnetic signal of the second coil L2 is dynamically adjusted by the driving adjustment circuit, and the second magnetic signal of the first coil L1 is adjusted based on the magnetic flux cancellation principle, and is adjusted in real time. Let the magnetic core work in a more stable state, improve the detection accuracy, and assist the magnetic flux balance during direct current or alternating current detection.

[0109] The closed-loop magnetic flux compensation part is: composed of a coupling and amplification closed-loop circuit 920, generates a reverse magnetic flux in the secondary coil Ls, and makes the three magnetic cores tend to a zero magnetic flux state, based on the zero magnetic flux principle, ensures the detection linearity and accuracy, and dynamically compensates the magnetic flux change.

[0110] The magnetic saturation recovery part is: by detecting the oscillation frequency of the first coil L1, it is judged whether the overall magnetic core is saturated, so as to judge whether the signal of demagnetizing the overall magnetic core is output to the coupling and amplification closed-loop circuit.

[0111] In a possible embodiment, the comparison circuit 921 can include a comparator, the input of the non-inverting input end of the comparator can be the Dout signal, and the input of the inverting input end can be the Aout and Zout signals.

[0112] In a possible embodiment, when the direct current is detected in the case that the overall magnetic core is not saturated, the Dout signal is input into the comparison circuit 921, the alternating current magnetic flux detection circuit 910 does not output a signal, and the saturation self-recovery circuit 930 also does not output a signal, at this time, the Dout signal is processed through the secondary coil Ls, and finally the detection of the direct current is completed.

[0113] In a possible embodiment, when the alternating current is detected in the case that the whole magnetic core is not saturated, the Aout signal is input into the comparison circuit 921, the direct current magnetic flux detection circuit 2100 does not output a signal, and the saturation self-recovery circuit 930 also does not output a signal. At this time, the Aout signal is processed through the secondary coil Ls, and finally the detection of the alternating current is completed.

[0114] In a possible embodiment, when the Zout signal is input into the comparison circuit 921 in the case that the whole magnetic core is saturated, the inverted magnetic flux is generated at the secondary coil Ls after processing, the three magnetic cores tend to be in the zero magnetic flux state, and the magnetic flux change is dynamically compensated.

[0115] Figure 10 A structure schematic diagram of a saturation self-recovery circuit in the embodiment of the present disclosure is shown in FIG. 9. Figure 10 As shown in FIG. 9, the saturation self-recovery circuit 930 includes a frequency detection circuit 931, a signal output circuit 932, and a signal generation circuit 933.

[0116] One end of the frequency detection circuit 931 is connected to the self-oscillation circuit 2110, for detecting the oscillation frequency value of the first coil L1, and is connected to Fout1 in the Figure 3

[0117] The signal output circuit 932 includes a first switch tube Q1, a first optocoupler U1, a second optocoupler U2, a first protection diode D3, and a second protection diode D4. Each optocoupler includes a light-emitting diode and a phototriode.

[0118] The gate of the first switch tube Q1 is connected to the frequency detection circuit 931, the source is grounded, and the drain is connected to the positive power supply Vcc. The light-emitting diodes in the first optocoupler U1 and the second optocoupler U2 are connected in parallel across the first switch tube Q1.

[0119] The signal generation circuit 933 generates a waveform by using an operational amplifier. The inverting input terminal of the operational amplifier in the signal generation circuit 933 is respectively connected to the emitter of the phototriode of the first optocoupler U1 and the collector of the phototriode of the second optocoupler U2. The collector of the phototriode of the first optocoupler U1 is connected to the first protection diode D3, and the emitter of the phototriode of the second optocoupler U2 is connected to the second protection diode D4.

[0120] When the frequency value is greater than a preset value, the first switch tube Q1 is turned off, the first optocoupler U1 and the second optocoupler U2 are turned on, and the waveform output by the signal generation circuit 933 is output as a demagnetization signal through the two protection diodes D3 and D4.

[0121] In a possible embodiment, when the alternating current is detected in the case that the whole magnetic core is not saturated, the Aout signal is input into the comparison circuit 921, the direct current magnetic flux detection circuit 2100 does not output a signal, and the saturation self-recovery circuit 930 also does not output a signal. At this time, the Aout signal is processed through the secondary coil Ls, and finally the detection of the alternating current is completed. Figure 10 ​The first switch tube Q1 in the circuit can be connected to the positive power supply Vcc via the resistor R24, and the output signal is output via the two protection diodes D3 and D4 as a demagnetization signal, and is output as a demagnetization signal via the resistor R25, which is represented as Zout.

[0122] Through the above circuit structure, when the oscillation frequency value of the first coil L1 is low, the first switch tube Q1 is turned on, the input of the first optocoupler U1 and the second optocoupler U2 is pulled to ground, and is in an off state, when the oscillation frequency value of the first coil L1 is high, the first switch tube Q1 is turned off, the input of the first optocoupler U1 and the second optocoupler U2 is the positive power supply, so that the light-emitting diode triggers the light-emitting triode to be turned on, and the waveform of the signal generating circuit 933 is processed via the two protection diodes D3 and D4 and output as a demagnetization signal.

[0123] The above circuit structure controls the on-off through the optocoupler, which can ensure the integrity of the output waveform, improve the integrity of the waveform input to the comparison circuit of the coupling and amplification closed loop circuit 920, improve the accuracy of the reverse magnetic flux generated by the secondary coil Ls, and improve the effect of magnetic flux compensation.

[0124] In a possible embodiment, the saturation self-recovery circuit 930 further includes a saturation state indicating circuit, and the saturation state indicating circuit includes a second switch tube and an indicating lamp.

[0125] The gate of the second switch tube is connected to the frequency detection circuit, the source is connected to the indicating lamp, and the drain is grounded; when the frequency value is greater than the preset value, the second switch tube is turned off, the indicating lamp is turned off, and the primary coil Lp is in a saturated state.

[0126] Figure 11 A structure diagram of a saturation state indicating circuit in an embodiment of the present disclosure is shown, as shown in Figure 11 The saturation state indicating circuit 1100 includes a second switch tube Q2 and an indicating lamp LED, and can further include a resistor R26 and a resistor R27. Figure 11 The connection relationship between the saturation state indicating circuit 1100 and the frequency detection circuit 931 is shown in

[0127] One end of the resistor R26 is connected to the frequency detection circuit 931, the other end is connected to the gate of the second switch tube Q2, the drain of the second switch tube Q2 is also connected to the frequency detection circuit 931 and grounded, the source of the second switch tube Q2 is connected to one end of the indicating lamp LED, and the other end of the indicating lamp LED is connected to the positive power supply Vcc via the resistor R27.

[0128] Figure 12 A structure diagram of an alternating current magnetic flux detection circuit in an embodiment of the present disclosure is shown, as shown in Figure 12 The alternating current magnetic flux detection circuit 910 includes a third coil L3 and a resistor R28.

[0129] One end of the resistor R28 is connected to the dotted end of the third coil L3, and the other end is connected to the comparison circuit 921, and outputs the Aout signal to the comparison circuit 921. The non-dotted end of the third coil L3 is grounded. Among them, Figure 13 The black dot on the upper side of the third coil L3 indicates the dotted end of the third coil L3, and the dotted end of the third coil L3 and the dotted end of the first coil L1 are homonymous.

[0130] The magnetic flux gate current sensor in the embodiment of the present disclosure is real-time dynamic to adjust the first magnetic communication signal of the second coil L2, so as to better compensate the second magnetic communication signal of the first coil L1, Figure 13 A flowchart of a signal adjusting method in an embodiment of the present disclosure is shown, which is applied to the above-mentioned magnetic flux gate current sensor, and the circuit structure of the magnetic flux gate current sensor will not be repeated. The method can be executed by a separate control unit, such as Figure 13 As shown, the method comprises the following steps: S1302: Obtain the second magnetic communication signal of the first coil.

[0131] S1304: According to the second magnetic communication signal, control the driving adjustment circuit to adjust the excitation signal generated by the second coil to adjust the first magnetic communication signal.

[0132] In a possible embodiment, the driving adjustment circuit comprises: an amplitude adjustment circuit, which can be any one of a first amplitude adjustment circuit, a second amplitude adjustment circuit, or a third amplitude adjustment circuit.

[0133] For S1304, the signal adjusting method in the present disclosure can further perform the following steps: For example, when it is detected that the voltage effective value of the second magnetic communication signal conversion is greater than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the voltage amplitude of the excitation signal generated by the second coil is controlled to be increased by the amplitude adjustment circuit, and the first magnetic communication signal is adjusted.

[0134] For example, when it is detected that the voltage effective value of the second magnetic communication signal conversion is less than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the voltage amplitude of the excitation signal generated by the second coil is controlled to be reduced by the amplitude adjustment circuit, and the first magnetic communication signal is adjusted.

[0135] In a possible embodiment, the driving adjustment circuit comprises: a first edge shaping circuit.

[0136] For S1304, the signal adjusting method in the present disclosure can further perform the following steps: Exemplarily, the voltage effective value of the second magnetic communication signal conversion is detected to be greater than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the first edge shaping circuit is controlled to increase the edge change rate of the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted.

[0137] Exemplarily, the voltage effective value of the second magnetic communication signal conversion is detected to be less than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the first edge shaping circuit is controlled to decrease the edge change rate of the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted.

[0138] In a possible embodiment, the drive adjustment circuit comprises a fourth amplitude adjustment circuit and a second edge shaping circuit. The fourth amplitude adjustment circuit can have a circuit structure similar to any one of the first amplitude adjustment circuit, the second amplitude adjustment circuit, or the third amplitude adjustment circuit. The second edge shaping circuit can have a circuit structure similar to the first edge shaping circuit.

[0139] For S1304, the signal adjustment method in the present disclosure can further perform the following steps: Exemplarily, the voltage effective value of the second magnetic communication signal conversion is detected to be greater than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the fourth amplitude adjustment circuit is controlled to increase the voltage amplitude of the excitation signal generated by the second coil, and / or the second edge shaping circuit is controlled to adjust to increase the edge change rate of the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted.

[0140] Exemplarily, the voltage effective value of the second magnetic communication signal conversion is detected to be less than the voltage effective value of the first magnetic communication signal conversion generated by the second coil, the fourth amplitude adjustment circuit is controlled to decrease the voltage amplitude of the excitation signal generated by the second coil, and / or the second edge shaping circuit is controlled to adjust to decrease the edge change rate of the excitation signal generated by the second coil, and the first magnetic communication signal is adjusted.

[0141] Based on the above method, through the real-time dynamic adjustment process, the magnetic communication signal of the second coil L2 is optimized. When adjusting the magnetic communication signal of the second coil L2, by adjusting the resistance value of the adjustable resistor, the adjustment size of the gain of the amplitude of the excitation signal of the second coil in different drive adjustment circuits or the edge change rate is changed, the amplitude can be adjusted only, the edge change rate can be adjusted only, or the amplitude and the edge change rate can be adjusted at the same time, so as to better compensate the magnetic flux of the first coil L1, so that the excitation noise generated by the first coil L1 and the second coil L2 can fine-tune the peak noise generated in the closed loop, and the magnetic flux can be counteracted in real time, so that the compensated magnetic flux is as close to 0 as possible, and the magnetic core works in a more stable state, improves the detection accuracy, and assists the magnetic flux balance during direct current or alternating current detection.

[0142] In the embodiments of the present disclosure, the terms "first", "second" and "third" are only used for descriptive purposes, and cannot be understood or implied to indicate or imply relative importance. The concepts of "first", "second", etc. mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0143] The term "and / or" in the present disclosure merely describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can represent three cases of existence of A alone, existence of A and B at the same time, and existence of B alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0144] Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon considering the disclosure herein, with the disclosure herein being merely illustrative of specific embodiments of the present disclosure.

[0145] The present disclosure is intended to cover any variations, uses, or adaptive changes of the present disclosure that follow the general principles of the present disclosure and include common knowledge or conventional technical means in the technical field of the present disclosure which are not disclosed by the present disclosure. The specification and examples are only considered as exemplary, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A fluxgate current sensor, characterized in that, include: The DC magnetic flux detection circuit includes a self-excited oscillation circuit and a balanced demagnetization circuit; The self-excited oscillation circuit includes: a first coil, wherein the self-excited oscillation circuit detects the DC current of the primary coil through the first coil; The balanced demagnetizing circuit includes: a drive adjustment circuit and a second coil; One end of the drive adjustment circuit is connected to the self-excited oscillation circuit, and the other end is connected to the second coil. It is used to process the excitation signal output by the self-excited oscillation circuit and adjust the first magnetic flux signal generated by the second coil according to the excitation signal. The balanced demagnetizing circuit is used to compensate the second magnetic flux signal of the first coil by the first magnetic flux signal generated by the second coil; the magnetic flux direction of the first magnetic flux signal is opposite to the magnetic flux direction of the second magnetic flux signal.

2. The fluxgate current sensor according to claim 1, characterized in that, The drive adjustment circuit includes: a first amplitude adjustment circuit for adjusting the amplitude of the excitation signal generated by the second coil and adjusting the first magnetic flux signal; the drive adjustment circuit is connected to the same-name terminal of the second coil relative to the first coil; The first amplitude adjustment circuit includes: an inverting amplifier; the inverting input terminal of the inverting amplifier is connected to the self-excited oscillation circuit, and the output terminal is connected to the second coil; at least one of the input resistor and the feedback resistor of the inverting amplifier is an adjustable resistor.

3. The fluxgate current sensor according to claim 1, characterized in that, The drive adjustment circuit includes: a second amplitude adjustment circuit, used to adjust the amplitude of the excitation signal generated by the second coil and adjust the first magnetic flux signal; the drive adjustment circuit is connected to the opposite end of the second coil relative to the first coil; The second amplitude adjustment circuit includes: an attenuation circuit and a first in-phase amplifier; the attenuation circuit is connected to the self-excited oscillation circuit, and its output is connected to the in-phase input terminal of the first in-phase amplifier; The output terminal of the first non-inverting amplifier is connected to the second coil; at least one of the grounding resistor and the feedback resistor of the first non-inverting amplifier is an adjustable resistor; The adjustment factor of the attenuation circuit is less than or equal to 1; the adjustment factor of the first in-phase amplifier is greater than or equal to 1.

4. The fluxgate current sensor according to claim 1, characterized in that, The drive adjustment circuit includes: a third amplitude adjustment circuit, used to adjust the amplitude of the excitation signal generated by the second coil and adjust the first magnetic flux signal; the drive adjustment circuit is connected to the opposite end of the second coil relative to the first coil; The third amplitude adjustment circuit includes: an amplification circuit, a reduction circuit, and an input control unit; The input control unit is connected to the self-excited oscillation circuit and is used to control the connection of the amplification circuit and the reduction circuit; The amplification circuit includes: a second non-inverting amplifier; the non-inverting input terminal of the second non-inverting amplifier is connected to the input control unit; the output terminal of the second non-inverting amplifier is connected to the second coil; at least one of the grounding resistor and the feedback resistor of the second non-inverting amplifier is an adjustable resistor; The amplitude reduction circuit includes a voltage divider circuit and a voltage follower; one end of the voltage divider circuit is connected to the input control unit, and the other end of the voltage divider circuit is connected to the non-inverting input terminal of the voltage follower; the output terminal of the voltage follower is connected to the second coil.

5. The fluxgate current sensor according to claim 1, characterized in that, The drive adjustment circuit includes: a first edge shaping circuit; One end of the first edge shaping circuit is connected to the self-excited oscillation circuit, and the other end is connected to the second coil. It is used to adjust the edge change rate of the excitation signal generated by the second coil and adjust the first magnetic flux signal.

6. The fluxgate current sensor according to claim 1, characterized in that, The drive adjustment circuit includes: a fourth amplitude adjustment circuit and a second edge shaping circuit; One end of the fourth amplitude adjustment circuit is connected to the self-excited oscillation circuit, and the other end of the fourth amplitude adjustment circuit is connected to the second edge shaping circuit, which is used to adjust the amplitude of the excitation signal generated by the second coil and adjust the first magnetic flux signal. The second edge shaping circuit is connected to the second coil and is used to adjust the edge change rate of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal.

7. The fluxgate current sensor according to claim 6, characterized in that, The second edge shaping circuit includes a first resistor; the larger the resistance value of the first resistor, the smaller the edge change rate; the first resistor is an adjustable resistor.

8. The fluxgate current sensor according to claim 1, characterized in that, Also includes: An AC magnetic flux detection circuit, comprising a third coil, wherein the AC magnetic flux detection circuit detects the AC current of the primary coil through the third coil.

9. The fluxgate current sensor according to claim 1, characterized in that, Also includes: A coupled amplification closed-loop circuit, comprising a comparator circuit, a current amplification circuit, and a secondary coil corresponding to the primary coil; The comparator circuit is connected to the self-excited oscillation circuit and the AC magnetic flux detection circuit. It is used to compare and process the signals input to the comparator circuit and transmit them to the input terminal of the current amplifier circuit. The output terminal of the current amplifier circuit is connected to the secondary coil.

10. The fluxgate current sensor according to claim 9, characterized in that, Also includes: A saturation self-recovery circuit is used to detect the saturation state of the primary coil and output a demagnetizing signal. The saturation self-recovery circuit is connected to the comparator circuit of the coupled amplification closed-loop circuit and transmits the demagnetizing signal to the secondary coil, causing the secondary coil to generate a reverse magnetic flux and demagnetize the core of the primary coil. The saturation self-recovery circuit includes: a frequency detection circuit, a signal output circuit, and a signal generation circuit; One end of the frequency detection circuit is connected to the self-excited oscillation circuit and is used to detect the oscillation frequency value of the first coil; The signal output circuit includes: a first switching transistor, a first optocoupler, a second optocoupler, a first protection diode, and a second protection diode; each optocoupler includes a light-emitting diode and a phototransistor. The gate of the first switching transistor is connected to the frequency detection circuit, the source is grounded, and the drain is connected to the positive power supply. The light-emitting diodes in the first optocoupler and the second optocoupler are connected in parallel across the two ends of the first switching transistor. The signal generating circuit is connected to the emitter of the phototransistor of the first optocoupler and the collector of the phototransistor of the second optocoupler, respectively. The collector of the phototransistor of the first optocoupler is connected to the first protection diode; the emitter of the phototransistor of the second optocoupler is connected to the second protection diode. When the frequency value is greater than the preset value, the first switch is turned off, the first optocoupler and the second optocoupler are turned on, and the waveform output by the signal generation circuit is output as the demagnetizing signal via the protection diode.

11. The fluxgate current sensor according to claim 10, characterized in that, The saturation self-recovery circuit further includes: a saturation state indication circuit; the saturation state indication circuit includes a second switching transistor and an indicator light. The gate of the second switching transistor is connected to the frequency detection circuit, the source is connected to the indicator light, and the drain is grounded. When the frequency value is greater than the preset value, the second switch is turned off, the indicator light is turned off, and the secondary coil is in a saturated state.

12. A signal conditioning method, characterized in that, It is applied to fluxgate current sensors, including self-excited oscillation circuit and balanced demagnetization circuit; The self-excited oscillation circuit includes: a first coil, wherein the self-excited oscillation circuit detects the DC current of the primary coil through the first coil; The balanced demagnetizing circuit includes: a drive adjustment circuit and a second coil; One end of the drive adjustment circuit is connected to the self-excited oscillation circuit, and the other end is connected to the second coil. It is used to process the excitation signal output by the self-excited oscillation circuit and adjust the first magnetic flux signal generated by the second coil according to the excitation signal. The balanced demagnetizing circuit is used to compensate the second magnetic flux signal of the first coil by the first magnetic flux signal generated by the second coil; the magnetic flux direction of the first magnetic flux signal is opposite to the magnetic flux direction of the second magnetic flux signal. The method includes: Obtain the second magnetic flux signal of the first coil; Based on the second magnetic flux signal, the drive adjustment circuit is controlled to adjust the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal.

13. The method according to claim 12, characterized in that, The drive adjustment circuit includes: an amplitude adjustment circuit, wherein the amplitude adjustment circuit is any one of a first amplitude adjustment circuit, a second amplitude adjustment circuit, or a third amplitude adjustment circuit; The step of controlling the drive adjustment circuit to adjust the excitation signal generated by the second coil and adjusting the first magnetic flux signal according to the second magnetic flux signal includes: If the effective voltage value of the second magnetic flux signal is detected to be greater than the effective voltage value of the first magnetic flux signal generated by the second coil, the amplitude adjustment circuit is controlled to increase the voltage amplitude of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal. If the effective voltage value of the second magnetic flux signal is less than the effective voltage value of the first magnetic flux signal generated by the second coil, the amplitude adjustment circuit is controlled to reduce the voltage amplitude of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal.

14. The method according to claim 12, characterized in that, The drive adjustment circuit includes: a first edge shaping circuit; The step of controlling the drive adjustment circuit to adjust the excitation signal generated by the second coil and adjusting the first magnetic flux signal according to the second magnetic flux signal includes: If the effective value of the voltage converted from the second magnetic flux signal is greater than the effective value of the voltage converted from the first magnetic flux signal generated by the second coil, the first edge shaping circuit is controlled to increase the edge change rate of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal. If the effective voltage value of the second magnetic flux signal is less than the effective voltage value of the first magnetic flux signal generated by the second coil, the first edge shaping circuit is controlled to reduce the edge change rate of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal.

15. The method according to claim 12, characterized in that, The drive adjustment circuit includes: a fourth amplitude adjustment circuit and a second edge shaping circuit; The step of controlling the drive adjustment circuit to adjust the excitation signal generated by the second coil and adjusting the first magnetic flux signal according to the second magnetic flux signal includes: If the effective voltage value of the second magnetic flux signal is detected to be greater than the effective voltage value of the first magnetic flux signal generated by the second coil, the fourth amplitude adjustment circuit is controlled to increase the voltage amplitude of the excitation signal generated by the second coil, and / or the second edge shaping circuit is controlled to adjust and increase the edge change rate of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal. If the effective voltage value of the second magnetic flux signal is less than the effective voltage value of the first magnetic flux signal generated by the second coil, the fourth amplitude adjustment circuit is controlled to reduce the voltage amplitude of the excitation signal generated by the second coil, and / or the second edge shaping circuit is controlled to adjust and reduce the edge change rate of the excitation signal generated by the second coil, thereby adjusting the first magnetic flux signal.

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