High-stability current source for power balance, control device, method and storage medium

Abstract

The invention relates to the technical field of metering, in particular to a high-stability current source for a power balance, a control device, a method and a storage medium, the current source comprises a first current source and a second current source, the first current source is connected with the second current source in parallel, and the significant digit of the first current source is greater than or equal to the significant digit of the second current source. The current value corresponding to the maximum range of the second current source is greater than the current value corresponding to the minimum resolution of the first current source, and compensating the current fluctuation of the first current source based on the second current source. According to the invention, the stability of the commercial digital current source is improved through digital feedback, so that the problem that the current source is difficult to meet the requirement of a power balance experiment for high stability of the current source in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a high-stability current source, a control device, a method and a storage medium for a power balance. Background Art

[0002] As the current international mainstream mass quantum standard device, the power balance has two measurement processes: weighing mode and speed mode. In weighing mode, the energized coil in the magnetic field is acted upon by a force that is balanced with the gravity of the weight being measured, namely:

[0003] BlI=mg (1)

[0004] Among them, B is the magnetic induction intensity at the coil position, l is the length of the coil, Bl is usually called the geometric factor, m is the mass of the weight being measured, and g is the local gravity acceleration. In the speed mode, the coil moves in the magnetic field to cut the magnetic flux lines, its speed is v, and the induced voltage in the coil is U, then the geometric factor can be expressed as:

[0005]

[0006] Substituting formula (2) into formula (1), we can get:

[0007]

[0008] Among them, U and I can be traced back to the quantum standard, and g and v can be traced back to the frequency and length standards through the interferometer-based measurement device. In this way, the mass m can be traced back to the quantum standard through the power balance. At present, the relative measurement uncertainty of 1kg weight calibrated using the most advanced power balance device can reach 1×10 -8 Therefore, the relative uncertainty of each physical quantity on the right side of formula (3) needs to reach 10 -9 magnitude, including the measurement uncertainty of the current in the coil.

[0009] In the power balance experiment, the current in the coil ranges from a few mA to 20 mA, and its working modes include constant current mode and constant force mode: in constant current mode, the current in the coil is required to remain constant, and its stability must reach the nA / A level; in constant force mode, the current in the coil needs to be adjusted in real time according to the position of the coil to ensure that the coil position remains constant. Usually, the adjustable current range is at the sub-microampere level, and the relative resolution also needs to reach the nA / A level.

[0010] However, the stability and resolution of the currently available commercial digital current sources cannot meet the requirements of power balance experiments under the condition of mA-level output. On the one hand, even if there are some high-end devices on the market that can provide better current stability, it is usually difficult to achieve fine adjustment at the sub-microampere level; on the other hand, although customized current sources can solve the above problems to a certain extent, their development and manufacturing involve relatively complex circuit design and technical implementation, accompanied by high costs. Summary of the invention

[0011] The present application provides a high-stability current source, a control device, a method and a storage medium for a power balance, so as to solve the problem in the related art that the current source is difficult to meet the high stability requirement of the power balance experiment for the current source.

[0012] A first aspect of the present application provides a high-stability current source for a power balance, including: a first current source and a second current source, wherein the first current source is connected in parallel with the second current source, the number of effective bits of the first current source is greater than or equal to the number of effective bits of the second current source, the current value corresponding to the maximum range of the second current source is greater than the current value corresponding to the minimum resolution of the first current source, and the current fluctuation of the first current source is compensated based on the second current source.

[0013] Optionally, a ratio of current values ​​corresponding to respective minimum resolutions of the second current source and the first current source is less than 0.01.

[0014] A second aspect of the present application provides a control device for a high-stability current source for a power balance, comprising: a servo resistor, wherein the servo resistor is connected in series with the power balance; a voltmeter, wherein the voltmeter is used to measure the voltage value across the servo resistor; the high-stability current source for the power balance of the first aspect, used to supply power to the servo resistor and the power balance; a host computer, used to control the high-stability current source for the power balance according to at least one of the voltage value across the servo resistor and the position of the coil in the power balance, so as to maintain the stability of the loop current within a first target range or maintain the coil position within a second target range.

[0015] Optionally, the control device of the high-stability current source for the power balance further includes: a mode selection switch, wherein the mode selection switch includes a first input terminal, a second input terminal and an output terminal, and the output terminal is connected to the high-stability current source for the power balance; a first PI controller, wherein the first PI controller is connected to the first input terminal and controls the output of the high-stability current source for the power balance in a constant current mode; and a second PI controller, wherein the second PI controller is connected to the second input terminal and controls the output of the high-stability current source for the power balance in a constant force mode.

[0016] Optionally, the host computer is also used to: use the difference between the loop current observation value and the required current as the input of the first PI controller in the constant current mode, and use the difference between the measured value and the set value of the coil position as the input of the second PI controller in the constant force mode.

[0017] Optionally, the power balance comprises a coil and a position sensor, wherein the position sensor is used to detect a measured value of the position of the coil.

[0018] Optionally, a ratio of a voltage value across the servo resistor to a resistance value of the servo resistor is a loop current observation value.

[0019] A third aspect embodiment of the present application provides a method for controlling a high-stability current source for a power balance, wherein the method is used to control the high-stability current source for a power balance of the first aspect, wherein the method comprises the following steps: obtaining a voltage value across a servo resistor and a measured value of a coil position in a power balance; controlling the high-stability current source for a power balance according to at least one of the voltage value across the servo resistor and the coil position in the power balance to maintain the stability of the loop current within a first target range or to maintain the coil position within a second target range.

[0020] Optionally, before obtaining the voltage value across the servo resistor and the measured value of the position of the coil in the power balance, the method further includes: preheating the servo resistor.

[0021] A fourth aspect of the present application provides a computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement a control method for a high-stability current source for a power balance as in the third aspect.

[0022] Therefore, this application has at least the following beneficial effects:

[0023] The embodiment of the present application sets a high-stability current source for a power balance, including a first current source and a second current source, connects the two in parallel, compensates the current fluctuation of the first current source based on the second current source, makes the current output reach the required high stability, and uses a control device of the high-stability current source for a power balance to control the mode and stability range of the current source, and the technical implementation is simple. Thus, the problem that the current source in the related art is difficult to meet the high stability requirements of the current source for the power balance experiment is solved.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of the structure of a high-stability current source for a power balance provided according to an embodiment of the present application;

[0027] Figure 2 A block diagram of a control device for a high-stability current source for a power balance provided in accordance with an embodiment of the present application;

[0028] Figure 3 This is an example diagram of a method for implementing a high-stability current source for a power balance according to an embodiment of the present application;

[0029] Figure 4 A schematic flow chart of a method for implementing a high-stability current source for a power balance according to an embodiment of the present application;

[0030] Figure 5 A wiring diagram provided according to an embodiment of the present application;

[0031] Figure 6 The loop current observation value provided according to an embodiment of the present application without adopting an external compensation method;

[0032] Figure 7 The Allan variance analysis result without using the external compensation method provided according to one embodiment of the present application;

[0033] Figure 8 An observed value of loop current using an external compensation method provided according to an embodiment of the present application;

[0034] Fig. 9 The Allan variance analysis result using the external compensation method provided according to one embodiment of the present application;

[0035] Fig.10 The present invention is a flowchart of a method for controlling a high-stability current source for a power balance according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0037] The following describes the high-stability current source, control device, method and storage medium for power balance of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the current source in the related art mentioned in the above background technology is difficult to meet the high stability requirements of the current source in the power balance experiment, the present application provides a high-stability current source for a power balance, the current source includes a first current source and a second current source, wherein the effective number of bits of the first current source is greater than or equal to the effective number of bits of the second current source, the current value corresponding to the maximum range of the second current source is greater than the current value corresponding to the minimum resolution of the first current source, the two are connected in parallel, and the current fluctuation of the first current source is compensated based on the second current source, so that the output of the current reaches the required high stability. Thus, the problem that the current source in the related art is difficult to meet the high stability requirements of the current source in the power balance experiment is solved.

[0038] Specifically, Figure 1 A schematic diagram of the structure of a high-stability current source for a power balance provided in an embodiment of the present application.

[0039] like Figure 1 As shown, the high stability current source 10 for the power balance includes: a first current source 101 and a second current source 102 .

[0040] Among them, the first current source 101 is connected in parallel with the second current source 102, the effective number of bits of the first current source 101 is greater than or equal to the effective number of bits of the second current source 102, the current value corresponding to the maximum range of the second current source 102 is greater than the current value corresponding to the minimum resolution of the first current source 101, and the current fluctuation of the first current source 101 is compensated based on the second current source 102.

[0041] It can be understood that the first current source 101 is connected in parallel with the second current source 102, and the two share the same voltage, and their respective output currents are added to form a total output current; the effective number of bits of the first current source 101 is greater than or equal to the effective number of bits of the second current source 102, which means that the accuracy of the first current source 101 is greater than that of the second current source 102, and can be used to provide high-precision current output, wherein the effective number of bits of the first current source is not less than four and a half digits, and it is recommended to use a five and a half digit digital current source; the maximum range current value of the second current source 102 is greater than the current value of the minimum resolution of the first current source 101, that is, the first current source 101 can provide current within a larger range, while the second current source 102 can provide higher accuracy within a smaller range; the second current source 102 is used to compensate for the current fluctuation of the first current source 101, and the implementation method is that the first current source 101 is responsible for providing a small current with high precision, and the second current source 102 compensates or supplements the additional large current demand, so that the high-stability current source 10 used for the power balance can handle large currents while also maintaining high accuracy.

[0042] In the embodiment of the present application, the ratio of the current values ​​corresponding to the respective minimum resolutions of the second current source 102 and the first current source 101 is less than 0.01.

[0043] Among them, the ratio of the current values ​​corresponding to the minimum resolutions of the second current source 102 and the first current source 101 needs to be less than 0.01 in order to ensure that the accuracy of the high-stability current source 10 used in the power balance can meet the requirements of the power balance experiment. If the ratio of the two is greater than 0.01, then in the constant current mode, the stability may not reach the nA / A level; in the constant force mode, the current adjustable range cannot reach the sub-microampere level, and the relative resolution cannot reach the nA / A level.

[0044] It is understandable that the embodiment of the present application stipulates that the ratio of the current values ​​corresponding to the respective minimum resolutions of the second current source 102 and the first current source 101 needs to be less than 0.01. If the ratio between the two is greater than 0.01, it means that the accuracy of the second current source 102 is insufficient and it is impossible to compensate the first current source 101 with high precision, resulting in the accuracy of the high-stability current source 10 used for the power balance failing to meet the requirements of the power balance experiment.

[0045] The high-stability current source for the power balance proposed in the embodiment of the present application includes a first current source and a second current source, which are connected in parallel. The current fluctuation of the first current source is compensated based on the second current source, so that the output current reaches the required high stability, and the technical implementation is simple.

[0046] Next, a control device for a high-stability current source for a power balance according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0047] Figure 2 It is a block diagram of a control device for a high-stability current source for a power balance according to an embodiment of the present application.

[0048] like Figure 2 As shown, the control device 20 of the high-stability current source for a power balance comprises: a servo resistor 201 , a voltmeter 202 , a high-stability current source 10 for a power balance and a host computer 203 .

[0049] Among them, the servo resistor 201 is connected in series with the power balance 30; the voltmeter 202 is used to measure the voltage value across the servo resistor 201; the high-stability current source 10 for the power balance is used to supply power to the servo resistor 201 and the power balance 30; the host computer 203 is used to control the high-stability current source 10 for the power balance according to at least one of the voltage value across the servo resistor 201 and the coil position in the power balance 30, so as to maintain the stability of the loop current within the first target range or maintain the coil position within the second target range.

[0050] Among them, the first target range refers to the stability range of the loop current in the constant current mode, and the second target range refers to the range of the coil position in the constant force mode. Both are ranges required by actual experiments and are not specifically limited here; the voltmeter 202 uses a nanovoltmeter, which can cooperate with PJVS (Programmable Josephson Junction Voltage Standard) to achieve accurate voltage standards.

[0051] It can be understood that the embodiment of the present application sets a high-precision resistor as the servo resistor 201, which is connected in series with the power balance 30, and the two are powered by the high-stability current source 10 of the power balance, and a voltmeter 202 is set to measure the voltage value across the servo resistor 201. The upper computer 203 uses the voltage value across the servo resistor 201 or the coil position in the power balance 30 to control the high-stability current source 10 of the power balance according to different measurement requirements to maintain the stability of the loop current within the first target range or maintain the coil position within the second target range. The specific control method will be described in detail below and will not be repeated here.

[0052] In the embodiment of the present application, the control device 20 for the high-stability current source for the power balance further includes: a mode selection switch, wherein the mode selection switch includes a first input terminal, a second input terminal and an output terminal, and the output terminal is connected to the high-stability current source for the power balance; a first PI controller, wherein the first PI controller is connected to the first input terminal and controls the output of the high-stability current source for the power balance in the constant current mode; and a second PI controller, wherein the second PI controller is connected to the second input terminal and controls the output of the high-stability current source for the power balance in the constant force mode.

[0053] Among them, the PI controller is a commonly used linear controller, which reduces the system error through proportional and integral actions. The PI controller module needs to be written so that it has the ability to control the output of the compensation current source. At the same time, the parameters of the PI controller can be adjusted according to the experimental results to obtain the optimal control parameters.

[0054] It can be understood that the embodiment of the present application also includes a mode selection switch, which has two input terminals to achieve the purpose of mode selection at one time, wherein the first input terminal is connected to the first PI controller, and is used to control the output of the high-stability current source for the power balance in the constant current mode; the second input terminal is connected to the second PI controller, and is used to control the output of the high-stability current source for the power balance in the constant force mode; the output terminal of the mode selection switch is connected to the high-stability current source 10 for the power balance, and is used to output a signal to control the high-stability current source 10 for the power balance.

[0055] In an embodiment of the present application, the host computer 203 is also used to: use the difference between the loop current observation value and the required current as the input of the first PI controller in the constant current mode, and use the difference between the measured value and the set value of the coil position as the input of the second PI controller in the constant force mode.

[0056] Among them, the demand current is the current value required for the power balance experiment; the setting value of the coil position is the preset coil position, both of which are set according to actual experimental requirements and are not specifically limited here.

[0057] It can be understood that in the embodiment of the present application, the host computer 203 is also used to calculate and control the input of the PI controller. In the constant current mode, the host computer 203 obtains the loop current observation value, calculates the difference between the loop current observation value and the demand current as the input of the first PI controller to improve the stability of the main current source; in the constant force mode, the host computer 203 obtains the measured value of the coil position, calculates the difference between the measured value of the coil position and the set value as the input of the second PI controller to maintain the coil position unchanged.

[0058] In the embodiment of the present application, the power balance 30 includes a coil and a position sensor, wherein the position sensor is used to detect a measured value of the coil position.

[0059] It can be understood that in the embodiment of the present application, the power balance 30 includes a coil and a position sensor, and the position sensor can provide high-precision position information for detecting the measured value of the coil position.

[0060] In the embodiment of the present application, the ratio of the voltage value across the servo resistor to the resistance value of the servo resistor is the loop current observation value.

[0061] It can be understood that the embodiment of the present application calculates the current value in the loop based on Ohm's law, and measures the voltage value across the servo resistor to calculate the ratio of the voltage value across the servo resistor to the resistance value of the servo resistor, which is the loop current observation value.

[0062] According to the control device of the high-stability current source for a power balance proposed in the embodiment of the present application, the mode and stability range of the high-stability current source for a power balance are controlled through the coordinated action of a servo resistor, a voltmeter, a high-stability current source for a power balance and a host computer. The technical implementation is simple, and the problem that the current source in the related technology is difficult to meet the high stability requirements of the current source for a power balance experiment is solved.

[0063] The control device for a high-stability current source for a power balance proposed in an embodiment of the present application is further described below through a specific embodiment.

[0064] like Figure 3As shown in FIG. 1 , a schematic diagram of a method for realizing a high-stability current source for a power balance provided in this embodiment is provided. In this method, a high-precision current source is used as a compensation current source to realize a high-stability current output under mA level output conditions. Since the requirements for current stability are more stringent in constant current mode, this embodiment is carried out in constant current mode. Figure 4 As shown, the method provided in this embodiment includes the following steps:

[0065] Step S301: Select commercial electrical measuring instruments: including a main current source (a five-and-a-half-bit digital current source is recommended) and a compensation current source, high-precision resistors, nanovoltmeters, etc.

[0066] In this embodiment, as an example, a Keithley 2410 five-and-a-half-digit digital current source is used as the main current source, and a Keithley 6221 four-and-a-half-digit digital current source is selected as the compensation current source. A high-precision resistor of model Alpha-HRU-100 is selected as the servo resistor in this embodiment, and its resistance is 100Ω. In this embodiment, a calibrated 3458A eight-and-a-half-digit digital voltmeter is used to replace the PJVS and nanovoltmeter to achieve high-precision measurement of the voltage across the servo resistor.

[0067] Step S302: Write and run the control program: including the instrument equipment control module, the loop current observation value calculation module, and the PI controller module.

[0068] Specifically, a control program is written and operated, including an instrument control module, a loop current observation value calculation module and a PI controller module. This embodiment does not specifically limit the computer language used to write the control program software, and the way to obtain the optimal parameters of the PI controller. In this embodiment, the control of the instrument, the calculation of the loop current observation value and the PI controller are realized based on the LabVIEW program, wherein the optimal parameters of the PI controller can be obtained by manual screening, and finally, the proportional coefficient is determined to be 2.5, and the integral coefficient is determined to be 0.2.

[0069] Step S303: Complete equipment wiring and parameter setting: After the main current source and the compensation current source are connected in parallel, they power the series circuit of the servo resistor and the coil; the output value of the main current source is set to the current value required for the power balance experiment; the output of the compensation current source is given by the PI controller.

[0070] First complete the device wiring, such as Figure 5The wiring diagram of this embodiment is shown. The servo resistor is placed in a constant temperature box. According to the manual of precision resistors, the temperature is set to 23°C. Then, the servo resistor is connected in series with the power balance using a coil. The coil resistance used in this embodiment is 400Ω, and 3458A is used to measure the voltage value across the servo resistor. Finally, the main current source and the compensation current source are connected in parallel to supply power to the series circuit of the coil and the servo resistor. In order to suppress the influence of thermoelectric effect on the voltage measurement results, it is recommended to use twisted copper wire as the connecting wire of related instruments and equipment in this embodiment. In this embodiment, the GPIB serial port is used to realize the digital communication between the digital current source, the digital voltmeter and the host computer.

[0071] Furthermore, the parameters of the instrument are set. In this embodiment, the demand current is 12.5mA, so the output value of the main current source is set to 12.5mA. Under this condition, the resolution of the main current source is 500nA; the range of the compensation current source is set to ±2μA, and the range of the compensation current source is set to ±2μA. Under this condition, the resolution of the compensation current source is 0.1nA. The number of 3458A reading bits is set to eight and a half digits.

[0072] Step S304: Complete the preheating of the instrumentation equipment, run the control program, and rely on the compensation current source to compensate for the fluctuation of the main current source to improve the stability of the loop current or maintain the coil position unchanged.

[0073] The instrument equipment is started to complete the preheating work. In this embodiment, the preheating time of the equipment is more than 4 hours, and the control program software is run to enable the digital current source to achieve a highly stable current output.

[0074] In order to quantitatively evaluate the effect of the method proposed in this embodiment on improving the output current stability of the digital current source, in this embodiment, an experimental test is first carried out without adding external compensation. The details are as follows:

[0075] When the setting value of the main current source output is 12.5mA, the loop current observation value is as follows Figure 6 As shown. Within the measurement time range, the fluctuation range of the voltage across the precision resistor is about 0.1μA. The reasons for the slight fluctuations in the voltage include: slight fluctuations in the output current of the digital current source, fluctuations in the resistance value of the servo resistor, and the like. By consulting the manual, it can be seen that the stability of the resistance value of the precision resistor used in this embodiment can reach ±0.05ppm / year, so the drift of the resistance value of the precision resistor used during the test can be ignored; and under an operating temperature environment of 23°C, the temperature coefficient of the resistance value of the precision resistor is ±0.05ppm / °C, while the temperature change in the temperature control box in this embodiment is ±1mK, so the variation range of the voltage measurement value caused by the ambient temperature of the precision resistor is about 1×10-10V, which can also be ignored.

[0076] The stability of loop current observations was analyzed using the Allan variance method. The results are as follows: Figure 7 As shown, the relative stability of the loop current observation value is about 350-1000nA / A. At the same time, the Allen variance analysis results show that when the external compensation current is not used, there is a low-frequency disturbance component with a large amplitude in the output value of the main current source, which makes its long-term stability poor.

[0077] Furthermore, when external current compensation is used, the loop current observation value is as follows: Figure 8 As shown in the figure, the gray line in the middle represents the average voltage across the precision resistor within 15 seconds. It can be seen that compared with the working condition without external current compensation, the fluctuation range of the voltage across the precision resistor has been reduced to 4μA. The Allan variance method is used again to analyze the voltage signal, and the results are shown in Fig. 9 As shown in the Allan variance analysis results, it can be seen that by using the method proposed in this embodiment, when the integration time is 200s, the relative stability of the loop current observation value can reach the nA / A level, which can meet the requirements of the power balance experiment.

[0078] It should be noted that in this embodiment, 3458A is used to measure the voltage across the servo resistor, and its measurement accuracy is lower than that of PJVS and nanovoltmeter. Therefore, when PJVS and nanovoltmeter are used, the stability of the output current can be further improved.

[0079] In summary, the method based on external compensation proposed in the embodiment of the present application can achieve ultra-high stability current output under mA level output conditions, which has certain practical value in power balance experiments.

[0080] The present application also provides a control method for a high-stability current source for a power balance, the method being used for the above-mentioned high-stability current source for a power balance, wherein: Fig.10 As shown, the method comprises the following steps:

[0081] In step S401: the voltage value across the servo resistor and the measured value of the coil position in the power balance are obtained.

[0082] The voltage value across the servo resistor is obtained by reading a voltmeter, and the measured value of the coil position in the power balance is obtained by a position sensor.

[0083] It can be understood that the embodiment of the present application obtains the voltage value across the servo resistor by adding a voltmeter across the servo resistor and uses a position sensor to obtain the measured value of the coil position in the power balance.

[0084] In the embodiment of the present application, before obtaining the voltage value across the servo resistor and the measured value of the coil position in the power balance, the method further includes: preheating the servo resistor.

[0085] The purpose of preheating the servo resistor is to reduce measurement errors or control instability caused by temperature changes.

[0086] It is understandable that in order to obtain more accurate measurement values ​​and reduce resistance value changes caused by temperature changes, the embodiment of the present application preheats the servo resistor before obtaining the voltage value across the servo resistor and the measurement value of the coil position in the power balance.

[0087] In step S402: the high stability current source of the power balance is controlled according to at least one of the voltage value across the servo resistor and the position of the coil in the power balance to maintain the stability of the loop current within a first target range or to maintain the coil position within a second target range.

[0088] Among them, the first target range refers to the stability range of the loop current in the constant current mode, and the second target range refers to the range of the coil position in the constant force mode. Both are ranges required by actual experiments and are not specifically limited here.

[0089] It can be understood that the embodiment of the present application controls the power balance to maintain the stability of the loop current within the first target range by obtaining the voltage value across the servo resistor, and controls the power balance to maintain the coil position within the second target range by using a high-stability current source.

[0090] It should be noted that the above explanation of the embodiment of the control device for a high-stability current source for a power balance is also applicable to the control method for a high-stability current source for a power balance of this embodiment, which will not be repeated here.

[0091] According to the control method of the high-stability current source for a power balance provided in the embodiment of the present application, by obtaining the voltage value across the servo resistor and the measured value of the coil position in the power balance, the high-stability current source for the power balance is controlled to maintain the stability of the loop current within a first target range or maintain the coil position within a second target range, thereby improving the stability of the commercial digital current source, meeting the fine requirements of the experiment, and having simple technical implementation.

[0092] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the above-mentioned control method of the high-stability current source for a power balance.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0095] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0096] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0097] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A high stability current source for a power balance, characterized in that: include: A first current source and a second current source, wherein the first current source is connected in parallel with the second current source, the effective number of bits of the first current source is greater than or equal to the effective number of bits of the second current source, the current value corresponding to the maximum range of the second current source is greater than the current value corresponding to the minimum resolution of the first current source, and the current fluctuation of the first current source is compensated based on the second current source.

2. The high stability current source for power balance according to claim 1, characterized in that: A ratio of current values ​​corresponding to respective minimum resolutions of the second current source and the first current source is less than 0.

01.

3. A control device for a high-stability current source for a power balance, characterized in that: include A servo resistor, wherein the servo resistor is connected in series with a coil for a power balance; A voltmeter, wherein the voltmeter is used to measure the voltage value across the servo resistor; The high stability current source for a power balance according to claim 1 or 2, used to supply power to the servo resistor and the power balance coil; The host computer is used to control the high-stability current source for the power balance according to at least one of the voltage value across the servo resistor and the position of the coil in the power balance to maintain the stability of the loop current within a first target range or to maintain the coil position within a second target range.

4. The control device for a high-stability current source for a power balance according to claim 3, characterized in that: Also includes: A mode selection switch, wherein the mode selection switch comprises a first input terminal, a second input terminal and an output terminal, and the output terminal is connected to the power balance with a high stability current source; A first PI controller, wherein the first PI controller is connected to the first input terminal and controls the power balance to output a high-stability current source in a constant current mode; A second PI controller, wherein the second PI controller is connected to the second input terminal and controls the power balance to output a high-stability current source in a constant force mode.

5. The control device for a high-stability current source for a power balance according to claim 4, characterized in that: The host computer is also used for: In the constant current mode, the difference between the loop current observation value and the required current is used as the input of the first PI controller, and in the constant force mode, the difference between the measured value and the set value of the coil position is used as the input of the second PI controller.

6. The control device for a high-stability current source for a power balance according to claim 5, characterized in that: The power balance comprises a coil and a position sensor, wherein the position sensor is used to detect a measured value of the position of the coil.

7. The control device for a high-stability current source for a power balance according to claim 5, characterized in that: The ratio of the voltage value across the servo resistor to the resistance value of the servo resistor is the loop current observation value.

8. A control method for a high stability current source for a power balance, characterized in that: The method is used to control the high-stability current source for the power balance according to claim 1 or 2, wherein the method comprises the following steps: Obtain the voltage value across the servo resistor and the measured value of the coil position in the power balance; The high stability current source for the power balance is controlled according to at least one of the voltage value across the servo resistor and the position of the coil in the power balance to maintain the stability of the loop current within a first target range or to maintain the coil position within a second target range.

9. The control method of a high-stability current source for a power balance according to claim 8, characterized in that: Before obtaining the voltage value across the servo resistor and the measured value of the coil position in the power balance, the method further includes: preheating the servo resistor.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the control method of the high-stability current source for a power balance according to claim 8 or 9.

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