Ripple compensation method suitable for magnetic flux type current sensor

Abstract

The invention relates to a ripple compensation method suitable for a magnetic flux type current sensor. The method comprises the steps that a ripple compensation unit matched with a direct-current induction magnetic core T1 is configured, the ripple compensation unit is used for conducting magnetic flux compensation on alternating excitation magnetic flux generated by the direct-current induction magnetic core T1, during magnetic flux compensation, the ripple compensation unit is used for generating compensation magnetic flux, the compensation magnetic flux comprises linear segment compensation magnetic flux and / or saturation segment excitation magnetic flux, and the linear segment compensation magnetic flux and / or the saturation segment excitation magnetic flux are / is used for compensating the alternating excitation magnetic flux generated by the direct-current induction magnetic core T1. When the compensation magnetic flux comprises the linear compensation magnetic flux, the linear segment compensation magnetic flux is matched with the linear segment excitation magnetic flux, so that the linear segment compensation magnetic flux is used for compensating the linear segment excitation magnetic flux; and when the compensation magnetic flux comprises the saturation section compensation magnetic flux, the saturation section compensation magnetic flux is matched with the saturation section excitation magnetic flux, so that the saturation section excitation magnetic flux is compensated by using the saturation section compensation magnetic flux. According to the invention, ripple compensation can be effectively realized, and the current measurement precision and reliability of the magnetic flux type current sensor are improved.

Description

Technical Field

[0001] The invention relates to a ripple compensation method, in particular to a ripple compensation method suitable for a flux type current sensor. Background Art

[0002] A current sensor is a device that can measure current. It can generally measure DC current or AC current. Since DC current has no transformer effect and cannot be directly coupled, traditional passive transformers cannot measure DC current. If DC current needs to be measured, active sensors are generally required, such as Hall current sensors or flux current sensors. The accuracy of Hall current sensors is generally between a few percent and a few thousandths, and flux current sensors are required for higher accuracy.

[0003] The flux current sensor may generally include a magnetic modulation current sensor or a fluxgate current sensor, which is a zero flux current sensor with closed-loop feedback. It can measure DC and AC currents, and the flux current sensor has a higher level of current measurement accuracy.

[0004] When working, the flux current sensor is based on the magnetic saturation of the internal magnetic core alternately excited. Therefore, when the flux current sensor works, it must include the modulation process. It can be seen that while achieving high-precision DC measurement function, a disadvantage will be introduced: during the modulation process, the output compensation current will inevitably have ripples, and the ripple frequency is equal to the modulation frequency. When ripples appear, on the one hand, it will affect the measured output, and on the other hand, it will also be coupled to the bus, interfering with the operation of the current source in the flux current sensor.

[0005] The flux current sensor has high accuracy and sensitivity, which means that the flux current sensor also has a large measurement dynamic range, that is, it can measure not only large currents but also small currents. When measuring small currents, the proportion of ripple in the total output cannot be ignored, which will affect the measurement accuracy of small signals.

[0006] In summary, how to perform ripple compensation on the flux current sensor, improve the accuracy of current measurement by the flux current sensor, and reduce the impact on busbar equipment is a difficult problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a ripple compensation method suitable for a flux type current sensor, which can effectively realize ripple compensation, improve the accuracy and reliability of current measurement of the flux type current sensor, and reduce the impact on bus equipment.

[0008] According to the technical solution provided by the present invention, a ripple compensation method applicable to a flux current sensor comprises:

[0009] A flux current sensor having a DC induction core T1 is provided with a ripple compensation unit adapted to the DC induction core T1, so that the ripple compensation unit is used to perform flux compensation on the alternating excitation flux generated by the DC induction core T1, and the ripple at the output end of the flux current sensor is reduced after the flux compensation, wherein:

[0010] The excitation magnetic flux is generated by the DC induction core T1 under the induction excitation signal, wherein the induction excitation signal includes a linear segment induction excitation and a saturation segment induction excitation, and the excitation magnetic flux includes a linear segment excitation magnetic flux corresponding to the linear segment induction excitation and a saturation segment excitation magnetic flux corresponding to the saturation segment induction excitation;

[0011] During flux compensation, a ripple compensation unit is used to generate a compensation flux, wherein the flux direction of the compensation flux is opposite to the flux direction of the excitation flux, and the compensation flux includes a linear segment compensation flux and / or a saturation segment excitation flux.

[0012] When the compensation magnetic flux includes the linear compensation magnetic flux, the linear segment compensation magnetic flux matches the linear segment excitation magnetic flux, so as to utilize the linear segment compensation magnetic flux to compensate the linear segment excitation magnetic flux;

[0013] When the compensation magnetic flux includes the saturation section compensation magnetic flux, the saturation section compensation magnetic flux matches the saturation section excitation magnetic flux, so as to utilize the saturation section compensation magnetic flux to compensate the saturation section excitation magnetic flux.

[0014] The ripple compensation unit at least includes a ripple compensation magnetic core T2 and an excitation control unit adaptively connected to the ripple compensation magnetic core T2, wherein:

[0015] The ripple compensation core T2 matches the DC induction core T1 in the flux current sensor and is adaptively connected to the DC induction core T1 to generate compensation flux using the ripple compensation core T2;

[0016] The excitation control unit includes a linear segment compensation unit and / or a saturation segment compensation unit, wherein:

[0017] When the excitation control unit includes a linear segment compensation unit, the ripple compensation core T2 receives an excitation source signal generated by an excitation source through the linear segment compensation unit, so as to perform linear compensation on the excitation source signal using the linear segment compensation unit, so as to generate a linearly compensated source signal after linear compensation;

[0018] Based on the linear compensation source signal, the ripple compensation core T2 generates a corresponding linear segment compensation excitation, and the ripple compensation core T2 generates a linear segment compensation flux based on the linear segment compensation excitation;

[0019] When the excitation control unit includes a saturation compensation unit, the saturation compensation unit is adaptively connected to the ripple compensation magnetic core T2, wherein:

[0020] The excitation source signal generates a saturation section compensation excitation based at least on the saturation section compensation unit and the ripple compensation magnetic core T2, and enables the ripple compensation magnetic core T2 to generate a saturation section compensation magnetic flux under the saturation section compensation excitation.

[0021] When the excitation control unit includes a linear segment compensation unit and a saturation segment compensation unit, and performs flux compensation, then:

[0022] The linear segment compensation unit is used to perform linear compensation on the excitation source signal, and the linearly compensated source signal is loaded onto the ripple compensation core T2. Thereafter, a flux compensation excitation is generated under the ripple compensation core T2 and the saturation segment compensation unit, and a compensation flux is generated based on the flux compensation excitation.

[0023] When the ripple compensation core T2 is adapted and connected to the DC induction core T1, it includes:

[0024] The non-identical end of the secondary coil of the DC induction core T1 is connected to the identical end of the secondary coil of the ripple compensation core T2;

[0025] The excitation signal generated by the excitation source is directly loaded to the same-name end of the primary coil of the DC induction core T1, and the non-same-name end of the primary coil of the DC induction core T1 is grounded through the induction core current sampling resistor;

[0026] When the excitation control unit includes a linear segment compensation unit, the source signal after linear compensation is loaded to the first end of the primary coil of the ripple compensation magnetic core T2 and connected, and a linear segment compensation excitation is generated at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the linear segment compensation excitation matches the linear segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1;

[0027] When the excitation control unit includes a saturation segment compensation unit, the saturation segment compensation unit is connected to the second end of the primary coil of the ripple compensation magnetic core T2 to generate a saturation segment compensation excitation at least at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the saturation segment compensation excitation matches the saturation segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1.

[0028] The linear segment compensation unit at least includes a forward amplification circuit formed based on an operational amplifier or a reverse amplification circuit formed based on an operational amplifier, wherein:

[0029] When the linear segment compensation unit is a forward amplifier circuit, the ripple compensation core T2 and the DC induction core T1 have opposite ends.

[0030] When the linear segment compensation unit is an inverse amplifier circuit, the same-named ends of the ripple compensation magnetic core T2 and the DC induction magnetic core T1 are the same.

[0031] The forward amplification circuit includes an operational amplifier OA2, wherein:

[0032] The in-phase terminal of the operational amplifier OA2 is connected to one end of the in-phase first resistor and one end of the in-phase second resistor, wherein the other end of the in-phase first resistor is connected to the output end of the excitation source, the second end of the in-phase second resistor is grounded, and the output end of the operational amplifier OA2 is connected to the first end of the primary coil of the ripple compensation magnetic core T2;

[0033] The inverting terminal of the operational amplifier OA2 is connected to one end of the reverse first resistor and one end of the reverse second resistor, wherein the other end of the reverse first resistor is grounded, and the other end of the reverse second resistor is connected to the output terminal of the operational amplifier OA2;

[0034] The reverse second resistor is an adjustable resistor. The resistance value of the reverse second resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

[0035] The reverse amplifier circuit includes an operational amplifier OA1, wherein:

[0036] The non-inverting terminal of the operational amplifier OA1 is connected to the ground;

[0037] The inverting terminal of the operational amplifier OA1 is connected to one end of the reverse third resistor and one end of the reverse fourth resistor, the other end of the reverse third resistor is grounded, the other end of the reverse fourth resistor is connected to the output terminal of the operational amplifier OA1, and the output terminal of the operational amplifier OA1 is connected to the first end of the primary coil of the ripple compensation magnetic core T2;

[0038] The reverse fourth resistor is an adjustable resistor. The resistance value of the reverse fourth resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

[0039] The saturation compensation unit at least includes a saturation adjustment resistor, wherein:

[0040] The resistance value of the saturation adjustment resistor is configured so that the saturation segment compensation excitation matches the saturation segment inductive excitation.

[0041] When the excitation control unit has only a linear segment compensation unit, the induction core current sampling resistor is selected as the adjustable resistor;

[0042] The resistance value of the inductive core current sampling resistor is adjusted to match the sum segment compensation excitation with the saturation segment inductive excitation.

[0043] The excitation source signal is a periodic waveform signal, wherein the waveform state of the periodic waveform signal includes a triangle wave, a sine wave, a trapezoidal wave or a square wave.

[0044] The advantages of the present invention are as follows: the ripple compensation unit can be used to perform flux compensation on the excitation flux generated by the DC induction core T1. The ripple compensation unit adopts a segmented compensation method. The linear segment compensation flux can be used to compensate the linear segment excitation flux, and the saturation segment compensation excitation can be used to compensate the saturation segment excitation flux. Through segmented compensation, high-precision flux compensation can be achieved, thereby effectively reducing the ripple at the output end of the flux current sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The figure is a flow chart of an embodiment of ripple compensation of the present invention.

[0046] Figure 2 A circuit diagram of an embodiment of ripple compensation according to the present invention.

[0047] Figure 3 This is a circuit diagram of another embodiment of ripple compensation of the present invention.

[0048] Figure 4 This is a circuit diagram of a third embodiment of ripple compensation according to the present invention.

[0049] Figure 5 This is a circuit diagram of the fourth embodiment of ripple compensation according to the present invention.

[0050] Figure 6 It is a comparative schematic diagram of an embodiment of the present invention in which only the ripple compensation magnetic core T2 is used for ripple compensation. DETAILED DESCRIPTION

[0051] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0052] In order to effectively realize ripple compensation and improve the accuracy and reliability of current measurement of a flux current sensor, the present invention provides a ripple compensation method applicable to a flux current sensor. Specifically, the ripple compensation method includes:

[0053] A flux current sensor having a DC induction core T1 is provided with a ripple compensation unit adapted to the DC induction core T1, so that the ripple compensation unit is used to perform flux compensation on the alternating excitation flux generated by the DC induction core T1, and the ripple at the output end of the flux current sensor is reduced after the flux compensation, wherein:

[0054] The excitation magnetic flux is generated by the DC induction core T1 under the induction excitation signal, wherein the induction excitation signal includes a linear segment induction excitation and a saturation segment induction excitation, and the excitation magnetic flux includes a linear segment excitation magnetic flux corresponding to the linear segment induction excitation and a saturation segment excitation magnetic flux corresponding to the saturation segment induction excitation;

[0055] During flux compensation, a ripple compensation unit is used to generate a compensation flux, wherein the flux direction of the compensation flux is opposite to the flux direction of the excitation flux, and the compensation flux includes a linear segment compensation flux and / or a saturation segment excitation flux.

[0056] When the compensation magnetic flux includes the linear compensation magnetic flux, the linear segment compensation magnetic flux matches the linear segment excitation magnetic flux, so as to utilize the linear segment compensation magnetic flux to compensate the linear segment excitation magnetic flux;

[0057] When the compensation magnetic flux includes the saturation section compensation magnetic flux, the saturation section compensation magnetic flux matches the saturation section excitation magnetic flux, so as to utilize the saturation section compensation magnetic flux to compensate the saturation section excitation magnetic flux.

[0058] It should be noted that the flux current sensor can be a commonly used sensor form, such as a magnetic modulation current sensor or a fluxgate current sensor. The type of flux current sensor and the working principle of the flux current sensor can be consistent with the prior art. Generally, the flux current sensor has a DC induction core T1, and the excitation source signal is loaded to the primary coil of the DC induction core T1. The DC induction core T1 can generate an alternating excitation flux. The way in which the DC induction core T1 generates an alternating excitation flux under the excitation source signal is consistent with the prior art. The situation of the excitation source signal can refer to the corresponding description below. In addition, the situation of the DC induction core T1 in the flux current sensor and the process of current measurement using the DC induction core T1 are consistent with the prior art.

[0059] It can be seen from the background technology that when the DC induction core T1 generates an alternating excitation flux, ripples will be generated. Therefore, when the present invention performs ripple compensation, it specifically refers to compensating for the ripples caused by the DC induction core T1 generating an alternating excitation flux. It can be understood that after ripple compensation, the accuracy and reliability of current measurement of the flux type current sensor can be improved, and the impact on the bus equipment can be reduced.

[0060] Figure 1 A flow chart of an embodiment of ripple compensation for a flux-type current sensor is shown. As can be seen from the figure, in order to achieve ripple compensation, at least a ripple compensation unit should be configured. The ripple compensation unit can be used to perform flux compensation on the excitation flux generated by the DC induction core T1. Therefore, the present invention reduces the ripple at the output end of the current sensor by performing flux compensation on the excitation flux, thereby achieving the purpose of ripple compensation.

[0061] It should be noted that the DC induction core T1 generally generates an excitation flux under an induction excitation signal. Figure 6 An embodiment of the induction excitation signal is shown in FIG. Figure 6 The red curve in the middle is the induction excitation signal. In the figure, the horizontal axis is time, and the vertical axis is the amplitude of the induction excitation signal. According to the waveform of the induction excitation signal shown in the figure, it can be seen that within one signal cycle, the induction excitation signal may include multiple linear segment induction excitations and multiple saturation segment induction excitations. The linear segment induction excitation is relatively smooth, and the saturation segment excitation has a peak. The figure also shows the situation where there is a transition segment. According to the waveform state of the induction excitation signal, the induction excitation waveform can be divided into linear segment induction excitation, saturation segment induction excitation and transition segment induction excitation.

[0062] Specifically, when the induction excitation signal is in the stage of linear segment induction excitation, a linear segment excitation flux can be generated through the DC induction core T1. When the induction excitation signal is in the stage of saturation segment induction excitation, a saturation segment excitation flux can be generated through the DC induction core T1. In addition, there is generally a transition stage excitation flux between the linear segment excitation flux and the saturation segment excitation flux. The situation of the transition stage excitation flux can refer to the corresponding descriptions of the linear segment excitation flux and the saturation segment excitation flux, which will not be repeated here.

[0063] In one embodiment of the present invention, the ripple compensation unit can generate a compensation magnetic flux, and the magnetic flux direction of the compensation magnetic flux should be opposite to the magnetic flux direction of the excitation magnetic flux, so that the compensation magnetic flux can be used to achieve magnetic flux compensation for the excitation magnetic flux. Figure 6 As can be seen from the above description, the linear segment excitation flux and the saturation segment excitation flux have different characteristics. The linear segment excitation flux has a higher amplitude, while the saturation segment excitation flux belonging to the same excitation flux does not necessarily have a higher amplitude. Therefore, in order to effectively achieve ripple compensation, the ripple compensation unit adopts a segmented compensation method, such as flux compensation for the linear segment excitation flux and / or the saturation segment excitation flux respectively. Therefore, the compensation flux may include the linear segment compensation flux and / or the saturation segment excitation flux. At this time, the linear segment compensation flux can be used to compensate the linear segment excitation flux, and the saturation segment compensation excitation can be used to compensate the saturation segment excitation flux. Through segmented compensation, high-precision flux compensation can be achieved, thereby effectively reducing the ripple at the output end of the flux current sensor.

[0064] It should be understood that the matching of the linear segment compensation flux and the linear segment excitation flux specifically means that the linear segment compensation flux and the linear segment excitation flux should be kept consistent as much as possible except for the different flux directions, so as to achieve a better compensation effect. Among them, keeping consistent generally means that the two are the same or the difference between the two is within an acceptable difference range, and the difference range can be selected and determined according to the needs of the actual application scenario. The specific corresponding meaning of the matching of the saturation segment compensation flux and the saturation segment excitation flux can be referred to the corresponding description here, and will not be repeated here.

[0065] In one embodiment of the present invention, the ripple compensation unit at least includes a ripple compensation magnetic core T2 and an excitation control unit adaptively connected to the ripple compensation magnetic core T2, wherein:

[0066] The ripple compensation core T2 matches the DC induction core T1 in the flux current sensor and is adaptively connected to the DC induction core T1 to generate compensation flux using the ripple compensation core T2;

[0067] The excitation control unit includes a linear segment compensation unit and / or a saturation segment compensation unit, wherein:

[0068] When the excitation control unit includes a linear segment compensation unit, the ripple compensation core T2 receives an excitation source signal generated by an excitation source through the linear segment compensation unit, so as to perform linear compensation on the excitation source signal using the linear segment compensation unit, so as to generate a linearly compensated source signal after linear compensation;

[0069] Based on the linear compensation source signal, the ripple compensation core T2 generates a corresponding linear segment compensation excitation, and the ripple compensation core T2 generates a linear segment compensation flux based on the linear segment compensation excitation;

[0070] When the excitation control unit includes a saturation compensation unit, the saturation compensation unit is adaptively connected to the ripple compensation magnetic core T2, wherein:

[0071] The excitation source signal generates a saturation section compensation excitation based at least on the saturation section compensation unit and the ripple compensation magnetic core T2, and enables the ripple compensation magnetic core T2 to generate a saturation section compensation magnetic flux under the saturation section compensation excitation.

[0072] In order to generate a compensating magnetic flux, the ripple compensation unit may include at least a ripple compensation magnetic core T2 and an excitation control unit. The ripple compensation magnetic core T2 matches the DC induction magnetic core T1 in the magnetic flux current sensor. Specifically, the ripple compensation magnetic core T2 matches the DC induction magnetic core T1, which specifically means that the two have consistent magnetic properties. For example, the ripple compensation magnetic core T2 and the DC induction magnetic core T1 can be two magnetic cores determined by the existing magnetic core pairing method. When the ripple compensation magnetic core T2 matches the DC induction magnetic core T1, the reliability of the excitation magnetic flux compensation can be effectively improved. After selecting the matching ripple compensation magnetic core T2, the ripple compensation magnetic core T2 should also be connected to the DC induction magnetic core T1. The connection state of the ripple compensation magnetic core T2 and the DC induction magnetic core T1 can be specifically referred to the corresponding description below.

[0073] It is understandable that, due to the limitations of the manufacturing process and processing technology of the magnetic core, there are obvious differences in the characteristics of each magnetic core, even between the same batch. Even if screening and matching are adopted, it is difficult to obtain magnetic cores with completely consistent characteristics. In addition, the screening process is time-consuming and labor-intensive, with high costs, low efficiency and poor results. Figure 6 FIG. 4 shows an embodiment of flux compensation using only the ripple compensation core T2. Figure 6 The blue curve in the middle is an embodiment of the ripple compensation core T2 generating a compensation excitation signal under the excitation source signal. The figure only shows the status of the compensation excitation signal and the induction excitation signal. It can be seen from the figure that there is a situation where the compensation excitation signal may not be able to completely follow the induction excitation signal. Therefore, when only the ripple compensation core T2 is used to perform flux compensation on the DC induction core T1, ripple compensation cannot be effectively achieved.

[0074] In order to improve the accuracy and reliability of ripple compensation, in one embodiment of the present invention, the ripple compensation unit should also include an excitation control unit, which can be used to excite and control the ripple compensation magnetic core T2 to generate the required linear segment compensation flux and / or saturation segment compensation flux. Specifically, the excitation control unit includes a linear segment compensation unit and / or a saturation segment compensation unit, and the excitation control unit can be selected as needed to meet the requirements of ripple compensation. The following is a specific description of the embodiments of the excitation control unit in different situations.

[0075] Specifically, when the excitation control unit includes a linear segment compensation unit, the ripple compensation core T2 receives an excitation source signal generated by an excitation source through the linear segment compensation unit, so as to perform linear compensation on the excitation source signal using the linear segment compensation unit, so as to generate a linearly compensated source signal after linear compensation; Figure 2 to Figure 5In the figure, SG is the excitation source, and the excitation source signal is a periodic waveform signal, wherein the waveform state of the periodic waveform signal includes a triangle wave, a sine wave, a trapezoidal wave or a square wave. Specifically, the excitation source signal is the signal generated by the excitation source, and the excitation source and the waveform state of the excitation source signal can be selected according to actual needs.

[0076] Depend on Figure 2 to Figure 5 It can be known that after the excitation source generates the excitation source signal, the excitation source signal is directly loaded onto the DC induction core T1. When the excitation control unit includes a linear segment compensation unit, the excitation source signal should be loaded onto the ripple compensation core T2 via the linear segment compensation unit. After linear compensation by the linear segment compensation unit, a linearly compensated source signal can be generated. The linearly compensated source signal is loaded onto the ripple compensation core T2. Thereafter, a linear segment compensation excitation and a corresponding linear segment compensation flux can be generated. It can be understood that the linear segment compensation excitation after linear compensation by the linear segment compensation unit can be consistent with the linear segment induction excitation, and thus the generated linear segment compensation flux can be used to realize the linear segment excitation flux compensation.

[0077] When the excitation control unit includes a saturation compensation unit, the saturation compensation unit is adaptively connected to the ripple compensation core T2. At this time, if the excitation control unit does not include a linear compensation unit, the excitation source signal should be directly loaded onto the ripple compensation core T2, and then the saturation compensation excitation is generated based on the saturation compensation unit and the ripple compensation core T2. If the excitation control unit includes a linear compensation unit and a saturation compensation unit, when flux compensation is performed, the excitation source signal is linearly compensated using the linear compensation unit, and the source signal after linear compensation is loaded onto the ripple compensation core T2, and then the flux compensation excitation is generated under the ripple compensation core T2 and the saturation compensation unit, and the compensation flux is generated based on the flux compensation excitation.

[0078] In one embodiment of the present invention, when the ripple compensation magnetic core T2 is adaptively connected to the DC induction magnetic core T1, it includes:

[0079] The non-identical end of the secondary coil of the DC induction core T1 is connected to the identical end of the secondary coil of the ripple compensation core T2;

[0080] The excitation signal generated by the excitation source is directly loaded to the same-name end of the primary coil of the DC induction core T1, and the non-same-name end of the primary coil of the DC induction core T1 is grounded through the induction core current sampling resistor;

[0081] When the excitation control unit includes a linear segment compensation unit, the source signal after linear compensation is loaded to the first end of the primary coil of the ripple compensation magnetic core T2 and connected, and a linear segment compensation excitation is generated at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the linear segment compensation excitation matches the linear segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1;

[0082] When the excitation control unit includes a saturation segment compensation unit, the saturation segment compensation unit is connected to the second end of the primary coil of the ripple compensation magnetic core T2 to generate a saturation segment compensation excitation at least at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the saturation segment compensation excitation matches the saturation segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1.

[0083] Figure 2 to Figure 5 An embodiment of the adaptive connection between the ripple compensation core T2 and the DC induction core T1 is shown in the figure. In the figure, R2 is the induction core current sampling resistor, which can convert the series current signal into a voltage signal and play the role of current limiting and adjusting the waveform peak. The type of the first end and the second end of the primary coil of the ripple compensation core T2 is generally related to the type of the linear segment compensation unit, which is specifically described below in conjunction with the figure.

[0084] In one embodiment of the present invention, the linear segment compensation unit at least includes a forward amplification circuit formed based on an operational amplifier or a reverse amplification circuit formed based on an operational amplifier, wherein:

[0085] When the linear segment compensation unit is a forward amplifier circuit, the ripple compensation core T2 has opposite ends with the same name as the DC induction core T1. Specifically, the first end of the primary coil of the ripple compensation core T2 is the non-same-name end of the primary coil of the ripple compensation core T2, and the second end of the primary coil of the ripple compensation core T2 is the same-name end of the primary coil of the ripple compensation core T2.

[0086] When the linear segment compensation unit is a reverse amplification circuit, the ripple compensation magnetic core T2 has the same end as the DC induction magnetic core T1. Specifically, the first end of the primary coil of the ripple compensation magnetic core T2 is the same end of the primary coil of the ripple compensation magnetic core T2, and the second end of the primary coil of the ripple compensation magnetic core T2 is the non-same end of the primary coil of the ripple compensation magnetic core T2.

[0087] During specific implementation, the linear segment compensation unit may be a forward amplifier circuit or a reverse amplifier circuit. The forward amplifier circuit and the reverse amplifier circuit are specifically described below.

[0088] In one implementation of the present invention, the forward amplifier circuit includes an operational amplifier OA2, wherein:

[0089] The in-phase terminal of the operational amplifier OA2 is connected to one end of the in-phase first resistor and one end of the in-phase second resistor, wherein the other end of the in-phase first resistor is connected to the output end of the excitation source, the second end of the in-phase second resistor is grounded, and the output end of the operational amplifier OA2 is connected to the first end of the primary coil of the ripple compensation magnetic core T2;

[0090] The inverting terminal of the operational amplifier OA2 is connected to one end of the reverse first resistor and one end of the reverse second resistor, wherein the other end of the reverse first resistor is grounded, and the other end of the reverse second resistor is connected to the output terminal of the operational amplifier OA2;

[0091] The reverse second resistor is an adjustable resistor. The resistance value of the reverse second resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

[0092] Figure 3 , in which R7 is a first resistor in phase, R8 is a second resistor in phase, R6 is a first resistor in reverse direction, and R5 is a second resistor in reverse direction. Specifically, the excitation source signal is divided by the first resistor in phase and the second resistor in phase, and then amplified by the operational amplifier OA2. When the operational amplifier OA2 is used for amplification, the gain of the operational amplifier OA2 is adjusted by the first resistor in reverse direction and the second resistor in reverse direction. Specifically, in order to achieve linear compensation, the gain of the operational amplifier OA2 should be adapted to "1", that is, the gain of the operational amplifier OA2 is 1 or deviates from 1 by an allowable range.

[0093] It should be noted that the linear segment specifically refers to the inductance of the DC induction core T1 and the ripple compensation core T2, which is not saturated and has high inductive reactance, wherein the inductive reactance value of the inductor is higher than the current sampling resistance of the induction core. At this time, the inductive reactance of the inductor mainly plays a role in the DC induction core T1 and the ripple compensation core T2 in series combination. When the gain setting of the operational amplifier OA2 is matched with "1", the amplitude of the linear segment compensation excitation can be matched with the amplitude of the linear segment inductive excitation.

[0094] Specifically, when linear compensation is performed by adjusting the resistance value of the reverse second resistor, the waveforms corresponding to the linear segment compensation excitation and the linear segment inductive excitation can be collected and observed. When the waveforms corresponding to the linear segment compensation excitation and the linear segment inductive excitation match, it can be considered that the resistance value of the reverse second resistor is adjusted to the target state, and the resistance value of the reverse second resistor is maintained at the target state. Thereafter, the forward amplification circuit can be used to perform linear compensation on the excitation source signal to generate a linearly compensated source signal after linear compensation. Specifically, the waveforms corresponding to the linear segment compensation excitation and the linear segment inductive excitation match, which specifically means that the linear segment compensation excitation and the linear segment inductive excitation are as close as possible.

[0095] In one embodiment of the present invention, the reverse amplifier circuit includes an operational amplifier OA1, wherein:

[0096] The non-inverting terminal of the operational amplifier OA1 is connected to the ground;

[0097] The inverting terminal of the operational amplifier OA1 is connected to one end of the reverse third resistor and one end of the reverse fourth resistor, the other end of the reverse third resistor is grounded, the other end of the reverse fourth resistor is connected to the output terminal of the operational amplifier OA1, and the output terminal of the operational amplifier OA1 is connected to the first end of the primary coil of the ripple compensation magnetic core T2;

[0098] The reverse fourth resistor is an adjustable resistor. The resistance value of the reverse fourth resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

[0099] Figure 2 , Figure 4 and Figure 5 An embodiment of a reverse amplifier circuit is shown in the figure, in which R1 is a reverse third resistor, and R3 is a reverse fourth resistor. When the reverse fourth resistor is an adjustable resistor, the resistance value of the reverse fourth resistor can be adjusted, thereby configuring the gain of the operational amplifier OA1. Generally, when the gain of the operational amplifier OA1 is large, the source signal generated after linear compensation is large, otherwise the amplitude of the source signal generated after linear compensation is small.

[0100] It should be noted that the principle of linear compensation using a reverse amplification circuit is consistent with the principle of linear compensation using a forward amplification circuit. The difference is that the method of connecting the primary coil of the ripple compensation core T2 is different. For the specific method and process of setting the resistance value of the reverse fourth resistor, please refer to the above-mentioned instructions for setting the reverse second resistor, which will not be repeated here.

[0101] In order to further improve the accuracy and automation of linear compensation, the control module can also be used to configure the linear compensation state of the forward amplifier circuit and the reverse amplifier circuit. Figure 4 and Figure 5 An embodiment of using a control module to configure a reverse amplifier circuit is shown in FIG. 1 , wherein the control module can be in a commonly used form, such as a commonly used microprocessor or computer device, and the type of the control module can be selected according to needs. When using a forward amplifier circuit, reference can be made to Figure 4 , Figure 5 and the corresponding instructions below.

[0102] Figure 4In the process, the linear segment induction excitation of the non-same-name end of the DC induction core T1 is collected, and the linear segment compensation excitation of the non-same-name end of the ripple compensation core T2 is collected at the same time. After that, the ADC (analog-to-digital conversion) converter ADC1 and the ADC converter ADC1 are converted and transmitted to the control module respectively. The control module decodes the corresponding middle areas of the linear segment induction excitation and the linear segment compensation excitation according to the corresponding waveforms. According to the middle area of ​​the linear segment induction excitation, the resistance value of the fourth resistor is reversed until the middle area of ​​the linear segment compensation excitation can be overlapped with the middle area of ​​the linear segment induction excitation as much as possible, that is, the waveforms corresponding to the linear segment compensation excitation and the linear segment induction excitation are matched.

[0103] Since the reverse fourth resistor is an adjustable resistor, the control module can adjust the resistance of the reverse fourth resistor according to the type of the reverse fourth resistor. The specific method and process of adjusting the reverse fourth resistor can be selected as needed and will not be repeated here.

[0104] Figure 5 In the process, the non-same-name end of the secondary side of the ripple compensation core T2 is sampled, and then the sampled signal is transmitted to the control module via the ADC converter ADC3. The control module can adjust the resistance value of the reverse fourth resistor in the above manner and make the peak-to-peak value or RMS (root mean square value, Root Mean Square) value of the collected signal at the minimum state.

[0105] Of course, you can also use Figure 4 and Figure 5 The method is shown in the figure, that is, the non-same-name ends of the secondary coil of the ripple compensation magnetic core T2, the non-same-name ends of the primary coil of the ripple compensation magnetic core T2, and the non-same-name ends of the primary coil of the DC induction magnetic core T1 are sampled at the same time, and the control module adjusts the resistance value of the reverse fourth resistor according to the sampling signal sampling method, so that the waveform corresponding to the linear segment compensation excitation and the linear segment induction excitation matches.

[0106] Depend on Figure 5 It can be known that the inductive excitation signal can generally include multiple linear segment inductive excitations, but when configuring the resistance value of the reverse fourth resistor, any linear segment inductive excitation can be used as a reference for linear compensation, that is, after selecting a linear segment inductive excitation, the corresponding linear segment compensation excitation is adjusted until the linear segment compensation excitation matches the selected linear segment inductive excitation. Thereafter, for other linear segment inductive excitations, the effect of matching the linear segment compensation excitation with the corresponding linear segment inductive excitation can be achieved.

[0107] In one embodiment of the present invention, the saturation compensation unit at least includes a saturation adjustment resistor, wherein:

[0108] The resistance value of the saturation adjustment resistor is configured so that the saturation segment compensation excitation matches the saturation segment inductive excitation.

[0109] Figure 2 to Figure 5 FIG. 4 shows an embodiment in which the saturation compensation unit uses a saturation adjustment resistor. In the figure, R4 is the saturation adjustment resistor. Figure 2 , Figure 4 and Figure 5 In the circuit, one end of the saturation adjustment resistor is connected to the non-same-name end of the primary coil of the ripple compensation magnetic core T2, and the other end of the saturation adjustment resistor is grounded. Figure 3 In the embodiment, one end of the saturation regulating resistor is connected to the same-name end of the primary coil of the ripple compensation magnetic core T2, and the other end of the saturation regulating resistor is grounded.

[0110] It should be noted that when in the saturation section, the DC induction core T1 and the ripple compensation core T2 are in the corresponding saturation state, and the corresponding inductance value is reduced. Therefore, the proportion of the saturation adjustment resistor in the total reactance of the series combination increases. Therefore, adjusting the resistance value of the saturation adjustment resistor can significantly adjust the peak value of the saturation section compensation excitation. It can be seen that when the resistance value of the saturation adjustment resistor is large, the corresponding peak of the saturation section compensation excitation is small, and when the resistance value of the saturation adjustment resistor is small, the corresponding peak of the saturation section compensation excitation is large.

[0111] In specific implementation, the resistance of the saturation regulating resistor is configured according to the corresponding relationship between the resistance of the saturation regulating resistor and the corresponding peak value of the saturation segment compensation excitation, and finally the saturation segment compensation excitation and the saturation segment induction excitation can be matched.

[0112] Depend on Figure 4 and Figure 5 It can be seen that the resistance value of the saturation adjustment resistor can also be configured using the control module. When using the configuration control module to configure the resistance value of the saturation adjustment resistor, you can refer to the above-mentioned adjustment instructions for adjusting the reverse fourth resistor and the resistance value of the saturation adjustment resistor. Specifically, it should be based on matching the saturation segment compensation excitation with the saturation segment induction excitation. No further details will be given here.

[0113] In one embodiment of the present invention, when the excitation control unit has only a linear segment compensation unit, the inductive core current sampling resistor is selected as an adjustable resistor;

[0114] The resistance value of the inductive core current sampling resistor is adjusted to match the sum segment compensation excitation with the saturation segment inductive excitation.

[0115] When the excitation control unit has only a linear segment compensation unit, it can be seen from the above description that only the linear segment compensation unit can be used for linear compensation, and the saturation segment compensation unit cannot be used for saturation segment compensation. At this time, the induction core current sampling resistor can be selected as an adjustable resistor, that is, the induction core current sampling resistor is a resistor with adjustable resistance.

[0116] It can be seen from the above description that when the resistance of the inductive core current sampling resistor is adjusted, the peak value of the saturation section inductive excitation can be adjusted. When the peak value of the saturation section inductive excitation is adjusted to match the saturation section compensation excitation, the purpose of the saturation section compensation unit performing saturation section compensation can be achieved. The principle and method of adjusting the resistance of the inductive core current sampling resistor can refer to the above corresponding description, and will not be repeated here.

[0117] It should be noted that the inductive excitation signal generally also includes multiple saturation segment inductive excitations. When performing saturation segment compensation, any saturation segment inductive excitation can be selected as a reference. Thereafter, the resistance value of the saturation adjustment resistor or the resistance value of the inductive core current sampling resistor is adjusted. When the saturation segment compensation excitation matches the saturation segment inductive excitation, the resistance value of the saturation adjustment resistor or the resistance value of the inductive core current sampling resistor is kept adjusted to achieve saturation segment compensation for all saturation segment inductive excitations.

Claims

1. A ripple compensation method for a flux current sensor, characterized in that: The ripple compensation method comprises: A flux current sensor having a DC induction core T1 is provided with a ripple compensation unit adapted to the DC induction core T1, so that the ripple compensation unit is used to perform flux compensation on the alternating excitation flux generated by the DC induction core T1, and the ripple at the output end of the flux current sensor is reduced after the flux compensation, wherein: The excitation magnetic flux is generated by the DC induction core T1 under the induction excitation signal, wherein the induction excitation signal includes a linear segment induction excitation and a saturation segment induction excitation, and the excitation magnetic flux includes a linear segment excitation magnetic flux corresponding to the linear segment induction excitation and a saturation segment excitation magnetic flux corresponding to the saturation segment induction excitation; During flux compensation, a ripple compensation unit is used to generate a compensation flux, wherein the flux direction of the compensation flux is opposite to the flux direction of the excitation flux, and the compensation flux includes a linear segment compensation flux and / or a saturation segment excitation flux. When the compensation magnetic flux includes the linear compensation magnetic flux, the linear segment compensation magnetic flux matches the linear segment excitation magnetic flux, so as to utilize the linear segment compensation magnetic flux to compensate the linear segment excitation magnetic flux; When the compensation magnetic flux includes the saturation section compensation magnetic flux, the saturation section compensation magnetic flux matches the saturation section excitation magnetic flux, so as to utilize the saturation section compensation magnetic flux to compensate the saturation section excitation magnetic flux.

2. The ripple compensation method for a flux current sensor according to claim 1, characterized in that: The ripple compensation unit at least includes a ripple compensation magnetic core T2 and an excitation control unit adaptively connected to the ripple compensation magnetic core T2, wherein: The ripple compensation core T2 matches the DC induction core T1 in the flux current sensor and is adaptively connected to the DC induction core T1 to generate compensation flux using the ripple compensation core T2; The excitation control unit includes a linear segment compensation unit and / or a saturation segment compensation unit, wherein: When the excitation control unit includes a linear segment compensation unit, the ripple compensation core T2 receives an excitation source signal generated by an excitation source through the linear segment compensation unit, so as to perform linear compensation on the excitation source signal using the linear segment compensation unit, so as to generate a linearly compensated source signal after linear compensation; Based on the linear compensation source signal, the ripple compensation core T2 generates a corresponding linear segment compensation excitation, and the ripple compensation core T2 generates a linear segment compensation flux based on the linear segment compensation excitation; When the excitation control unit includes a saturation compensation unit, the saturation compensation unit is adaptively connected to the ripple compensation magnetic core T2, wherein: The excitation source signal generates a saturation section compensation excitation based at least on the saturation section compensation unit and the ripple compensation magnetic core T2, and enables the ripple compensation magnetic core T2 to generate a saturation section compensation magnetic flux under the saturation section compensation excitation.

3. The ripple compensation method for a flux current sensor according to claim 2, characterized in that: When the excitation control unit includes a linear segment compensation unit and a saturation segment compensation unit, and performs flux compensation, then: The linear segment compensation unit is used to perform linear compensation on the excitation source signal, and the source signal after linear segment compensation is loaded onto the ripple compensation core T2. Thereafter, a flux compensation excitation is generated under the ripple compensation core T2 and the saturation segment compensation unit, and a compensation flux is generated based on the flux compensation excitation.

4. The ripple compensation method for a flux current sensor according to claim 2, characterized in that: When the ripple compensation core T2 is adapted and connected to the DC induction core T1, it includes: The non-identical end of the secondary coil of the DC induction core T1 is connected to the identical end of the secondary coil of the ripple compensation core T2; The excitation signal generated by the excitation source is directly loaded to the same-name end of the primary coil of the DC induction core T1, and the non-same-name end of the primary coil of the DC induction core T1 is grounded through the induction core current sampling resistor; When the excitation control unit includes a linear segment compensation unit, the source signal after linear segment compensation is loaded to the first end of the primary coil of the ripple compensation magnetic core T2 and connected, and a linear segment compensation excitation is generated at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the linear segment compensation excitation matches the linear segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1; When the excitation control unit includes a saturation segment compensation unit, the saturation segment compensation unit is connected to the second end of the primary coil of the ripple compensation magnetic core T2 to generate a saturation segment compensation excitation at least at the second end of the primary coil of the ripple compensation magnetic core T2, wherein the saturation segment compensation excitation matches the saturation segment induction excitation formed by the non-same-name end of the primary coil of the DC induction magnetic core T1.

5. The ripple compensation method for a flux current sensor according to claim 4, characterized in that: The linear segment compensation unit at least includes a forward amplification circuit formed based on an operational amplifier or a reverse amplification circuit formed based on an operational amplifier, wherein: When the linear segment compensation unit is a forward amplifier circuit, the ripple compensation core T2 and the DC induction core T1 have opposite ends. When the linear segment compensation unit is an inverse amplifier circuit, the same-named ends of the ripple compensation magnetic core T2 and the DC induction magnetic core T1 are the same.

6. The ripple compensation method for a flux current sensor according to claim 5, characterized in that: The forward amplification circuit includes an operational amplifier OA2, wherein: The in-phase terminal of the operational amplifier OA2 is connected to one end of the in-phase first resistor and one end of the in-phase second resistor, wherein the other end of the in-phase first resistor is connected to the output end of the excitation source, the second end of the in-phase second resistor is grounded, and the output end of the operational amplifier OA2 is connected to the first end of the primary coil of the ripple compensation magnetic core T2; The inverting terminal of the operational amplifier OA2 is connected to one end of the reverse first resistor and one end of the reverse second resistor, wherein the other end of the reverse first resistor is grounded, and the other end of the reverse second resistor is connected to the output terminal of the operational amplifier OA2; The reverse second resistor is an adjustable resistor. The resistance value of the reverse second resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

7. The ripple compensation method for a flux current sensor according to claim 6, characterized in that: The reverse amplifier circuit includes an operational amplifier OA1, wherein: The non-inverting terminal of the operational amplifier OA1 is connected to the ground; The inverting terminal of the operational amplifier OA1 is connected to one end of the reverse third resistor and one end of the reverse fourth resistor, the other end of the reverse third resistor is grounded, the other end of the reverse fourth resistor is connected to the output terminal of the operational amplifier OA1, and the output terminal of the operational amplifier OA1 is connected to the first end of the primary coil of the ripple compensation magnetic core T2; The reverse fourth resistor is an adjustable resistor. The resistance value of the reverse fourth resistor is adjusted to configure a linear compensation state for the excitation source signal so that the linear segment compensation excitation matches the linear segment induction excitation.

8. The ripple compensation method for a flux current sensor according to any one of claims 2 to 7, characterized in that: The saturation compensation unit at least includes a saturation adjustment resistor, wherein: The resistance value of the saturation adjustment resistor is configured so that the saturation segment compensation excitation matches the saturation segment inductive excitation.

9. The ripple compensation method for a flux current sensor according to any one of claims 4 to 7, characterized in that: When the excitation control unit has only a linear segment compensation unit, the induction core current sampling resistor is selected as the adjustable resistor; The resistance value of the inductive core current sampling resistor is adjusted to match the sum segment compensation excitation with the saturation segment inductive excitation.

10. The ripple compensation method for a flux current sensor according to any one of claims 2 to 7, characterized in that: The excitation source signal is a periodic waveform signal, wherein the waveform state of the periodic waveform signal includes a triangle wave, a sine wave, a trapezoidal wave or a square wave.

Images