A clamping system and method

Abstract

The present invention provides a clamping system and method to improve the clamping accuracy. The clamping system of the present invention includes a differential operational amplifier, a compensation operational amplifier, a single-direction conduction diode, a main circuit output circuit, and a acquisition circuit. The differential operational amplifier is connected to the compensation operational amplifier, the compensation operational amplifier is connected to the single-direction conduction diode, the single-direction conduction diode is connected to the main circuit output circuit, the acquisition circuit is connected to the main circuit output circuit, and the acquisition circuit is connected to the differential operational amplifier. In the clamping system of this embodiment, a compensation operational amplifier is arranged between the differential operational amplifier and the single-direction conduction diode, which can compensate the conduction voltage difference of the diode, reduce the fixed deviation of the output, and improve the clamping accuracy. The clamping method of this embodiment establishes a correction model based on the theoretical output value and the actual output value, and uses the correction model to correct the first preset value and the second preset value, reduce the system output deviation, and improve the clamping accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and particularly relates to a clamping system and method. Background Art

[0002] Clamping refers to a measure of restricting the potential of a certain point to a specified potential, which is an overvoltage protection technology and is realized through a clamping circuit. In the existing clamping circuit, a bidirectional diode is directly connected to the feedback operational amplifier. Due to the conduction voltage difference of the diode, this conduction voltage difference causes a fixed deviation in clamping, and the clamping error is generally in the range of 10%, or even higher. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a clamping system and method to improve the clamping accuracy.

[0004] To solve the above technical problem, an embodiment of the present invention provides a clamping system, including a differential operational amplifier, a compensation operational amplifier, a unidirectional conduction diode, a main circuit output circuit, and a acquisition circuit. The output end of the differential operational amplifier is connected to the input end of the compensation operational amplifier, the output end of the compensation operational amplifier is connected to one end of the unidirectional conduction diode, the other end of the unidirectional conduction diode is connected to the input end of the main circuit output circuit, the input end of the acquisition circuit is connected to the output end of the main circuit output circuit, and the input end of the acquisition circuit is connected to the input end of the differential operational amplifier; it further includes a first digital-to-analog converter and a second digital-to-analog converter. The output end of the first digital-to-analog converter is connected to the input end of the main circuit output circuit, and the output end of the second digital-to-analog converter is connected to the input end of the differential operational amplifier.

[0005] As a further improvement of the embodiment of the present invention, it further includes a calibration measurement module, and the calibration measurement module is connected to the output end of the main circuit output circuit.

[0006] As a further improvement of the embodiment of the present invention, it further includes an operation module and a data communication module. The input end of the operation module is connected to the output end of the calibration measurement module, the output end of the operation module is connected to the input end of the data communication module, and the output end of the data communication module is respectively connected to the input ends of the first digital-to-analog converter and the second digital-to-analog converter.

[0007] As a further improvement of the embodiment of the present invention, the calibration measurement circuit includes a measuring instrument.

[0008] As a further improvement of the embodiment of the present invention, the calibration measurement circuit further includes a detection resistor. The detection resistor is connected in series to the output end of the main circuit output circuit, and the measuring instrument is connected in parallel across both ends of the detection resistor.

[0009] As a further improvement of the embodiment of the present invention, the acquisition circuit includes a first amplifier. The input end of the first amplifier is connected to the output end of the main loop output circuit, and the output end of the first amplifier is connected to the input end of the differential operational amplifier.

[0010] As a further improvement of the embodiment of the present invention, the main loop output circuit includes a second amplifier. The input end of the second amplifier is respectively connected to the output end of the single-phase conduction diode and the output end of the first digital-to-analog converter.

[0011] On the other hand, an embodiment of the present invention provides a clamping method. Based on the above clamping system, the clamping method includes the following steps:

[0012] Step 10): Determine n test theoretical values, and obtain n test first preset values and n test second preset values according to the test theoretical values; n represents an integer greater than or equal to 2;

[0013] Step 20): Sequentially set n test first preset values in the first digital-to-analog converter, sequentially set n test second preset values in the second digital-to-analog converter, and measure the output end of the main loop output circuit to obtain n actual output values;

[0014] Step 30): According to the test theoretical values and the actual output values, obtain a correction model as shown in Equation (1):

[0015] Y = AX + B Equation (1)

[0016] In the formula, Y represents the theoretical output value, X represents the actual output value, A represents the first coefficient, and B represents the second coefficient;

[0017] Step 40): Through the correction model, obtain the theoretical output value according to the expected output value, obtain the first preset value and the second preset value according to the theoretical output value, set the first preset value in the first digital-to-analog converter, and set the second preset value in the second digital-to-analog converter.

[0018] Compared with the prior art, the technical solution of the present invention has the following beneficial effects: providing a clamping system and method to improve the clamping accuracy. In the clamping system of this embodiment, a compensation operational amplifier is provided between the differential operational amplifier and the single-phase conduction diode, which can compensate for the conduction voltage difference of the diode, reduce the fixed deviation of the output, and improve the clamping accuracy. In the clamping method of this embodiment, a correction model is established according to the theoretical output value and the actual output value, and the theoretical output value is obtained by using the correction model and the expected output value, and then the first preset value and the second preset value used for setting in the first digital-to-analog converter and the second digital-to-analog converter are corrected, so that the output values of the first digital-to-analog converter and the second digital-to-analog converter are more accurate, reducing the system output deviation and improving the clamping accuracy. Description of the Drawings

[0019] Figure 1 It is the structural block diagram of the clamping system according to an embodiment of the present invention;

[0020] Figure 2 It is the structural block diagram of the clamping system according to a preferred embodiment of the present invention;

[0021] Figure 3 It is the circuit diagram of the clamping system according to an embodiment of the present invention.

[0022] In the figure: differential operational amplifier 1, compensation operational amplifier 2, single-way conduction diode 3, main circuit output circuit 4, acquisition circuit 5, first digital-to-analog converter 6, second digital-to-analog converter 7, calibration measurement module 8, operation module 10, data communication module 11. Specific embodiments

[0023] Next, in conjunction with the accompanying drawings, the technical solutions of the present invention will be described in detail.

[0024] An embodiment of the present invention provides a clamping system, as Figure 1 shown, including a differential operational amplifier 1, a compensation operational amplifier 2, a single-way conduction diode 3, a main circuit output circuit 4, and an acquisition circuit 5. The output end of the differential operational amplifier 1 is connected to the input end of the compensation operational amplifier 2. The output end of the compensation operational amplifier 2 is connected to one end of the single-way conduction diode 3. The other end of the single-way conduction diode 3 is connected to the input end of the main circuit output circuit 4. The input end of the acquisition circuit 5 is connected to the output end of the main circuit output circuit 4. The output end of the acquisition circuit 5 is connected to the input end of the differential operational amplifier 1. It further includes a first digital-to-analog converter 6 and a second digital-to-analog converter 7. The output end of the first digital-to-analog converter 6 is connected to the input end of the main circuit output circuit 4. The output end of the second digital-to-analog converter 7 is connected to the input end of the differential operational amplifier 1. Among them, the first digital-to-analog converter 6 is used to convert a set first preset value into voltage or current, and the second digital-to-analog converter 7 is used to convert a set second preset value into voltage or current.

[0025] The working process of the clamping system in the above embodiment is as follows:

[0026] The theoretical output value is the expected output value. Based on the theoretical output value, a first preset value for setting in the first digital-to-analog converter 6 and a second preset value for setting in the second digital-to-analog converter 7 are obtained. The first digital-to-analog converter 6 converts the first preset value into a first analog quantity and outputs it to the main circuit output circuit 4, and the main circuit output circuit 4 outputs the actual output quantity. The acquisition circuit 5 feeds back the actual output quantity to the differential operational amplifier 1. The second digital-to-analog converter 7 converts the second preset value into a second analog quantity and outputs it to the differential operational amplifier 1. The differential operational amplifier 1 compares the actual output quantity with the second analog quantity and outputs a difference quantity to the compensation operational amplifier 2. The compensation operational amplifier 2 follows the compensation single-conduction diode 3, and the single-conduction diode 3 is in a conducting state.

[0027] For the clamping system of the above embodiment, a compensation operational amplifier 2 is provided between the differential operational amplifier 1 and the single-conduction diode 3. Since the output of the operational amplifier must have feedback, without feedback, the output will reach the full bias to the power supply value. Therefore, setting the compensation operational amplifier 2 will keep the single-conduction diode 3 in a conducting state all the time. As Figure 3 shown, the output of pin 3 of the compensation operational amplifier 2 is 0. The pin 2 of the compensation operational amplifier 2 follows the single-conduction diode 3, and the pin 2 of the single-conduction diode 3 will also be 0. Only in this way can the compensation operational amplifier 2 reach balance. So at this time, the voltage of pin 1 of the compensation operational amplifier is 0.5V. The compensation operational amplifier 2 can compensate the voltage difference of the single-conduction diode 3, reduce the fixed deviation of the system output, and improve the clamping accuracy.

[0028] As a preferred example, as Figure 2 shown, the clamping system of this embodiment further includes a calibration measurement module 8, and the calibration measurement module 8 is connected to the output end of the main circuit output circuit 4.

[0029] For the clamping system of the above embodiment, the calibration measurement module 8 is used to measure the actual output to obtain the actual output value. Multiple test theoretical output values are set. Based on the test theoretical output values, test first preset values and test second preset values are obtained, which are respectively set through the first digital-to-analog converter 6 and the second digital-to-analog converter 7. Through the calibration measurement module, corresponding multiple actual output values are measured. The measured actual output values are used as input variables of the correction model, and the test theoretical output values are used as output variables of the correction model to obtain the first coefficient A and the second coefficient B of the correction model, thereby obtaining the correction model. The expression of the correction model is as shown in Equation (1):

[0030] Y = AX + B Equation (1)

[0031] Wherein, X represents the expected output value, Y represents the theoretical output value, A represents the first coefficient, and B represents the second coefficient.

[0032] Using the correction model, the theoretical output value can be obtained based on the expected output value, and then the first preset value and the second preset value can be obtained. Thus, the first preset value for setting in the first digital-to-analog converter 6 and the second preset value for setting in the second digital-to-analog converter 7 can be corrected, that is, the output values of the first digital-to-analog converter 6 and the second digital-to-analog converter 7 are corrected, making the output values of the first digital-to-analog converter 6 and the second digital-to-analog converter 7 more accurate, reducing the system output deviation, improving the clamping accuracy, and the clamping accuracy is improved from 10% before to 0.1%. The improvement of the clamping accuracy plays a more accurate positioning role in product test protection.

[0033] As a preferred example, the calibration and detection module 8 includes a measuring instrument. Preferably, the measuring instrument uses a multimeter.

[0034] When the clamping system of this embodiment is used to clamp the output of the voltage source, the output voltage is directly measured using a measuring instrument.

[0035] When the clamping system of this embodiment is used to clamp the output of the current source, preferably, the calibration and detection module further includes a detection resistor. The detection resistor is connected in series at the output end of the main loop output circuit, and the measuring instrument is connected in parallel across both ends of the detection resistor. As Figure 3 shown, when the switch S3 is closed, the measuring instrument measures the voltage of the detection resistor to obtain the output current.

[0036] As a preferred example, as Figure 2 shown, the clamping system of this embodiment further includes an operation module 10 and a data communication module 11. The input end of the operation module 10 is connected to the output end of the calibration and measurement module 8, the output end of the operation module 10 is connected to the input end of the data communication module 11, and the output end of the data communication module 11 is respectively connected to the input ends of the first digital-to-analog converter 6 and the second digital-to-analog converter 7.

[0037] The calibration and measurement module 8 sends the actually measured output value to the operation module 10. The operation module 10 uses the actually measured output value as the input variable of the correction model and the theoretical output value as the output variable of the correction model to obtain the correction model. The expression of the correction model is as shown in Equation (1):

[0038] Y = AX + B Equation (1)

[0039] Wherein, X represents the actually measured output value, and Y represents the theoretical output value.

[0040] The operation module 10 uses the correction model to obtain the theoretical output value based on the expected output value. The operation module 10 then obtains the first preset value and the second preset value according to the theoretical output value, and transmits the first preset value to the first digital-to-analog converter 6 and the second preset value to the second digital-to-analog converter 7 through the data communication module 11.

[0041] The system of this embodiment realizes automatically correcting the first preset value and the second preset value according to the actual output through the calibration measurement module 8, the operation module 10, and the data communication module 11, obtaining more accurate first and second preset values, compensating for the output deviation of the entire system, making the system output value closer to the desired clamped output value, and improving the clamping accuracy.

[0042] As a preferred example, the acquisition circuit 5 includes a first amplifier. The input end of the first amplifier is connected to the output end of the main circuit output circuit 4, and the output end of the first amplifier is connected to the input end of the differential operational amplifier 1. The first amplifier feeds back the output value of the main circuit output circuit to the differential operational amplifier 1 in proportion.

[0043] As a preferred example, the main circuit output circuit 4 includes a second amplifier. The input end of the second amplifier is respectively connected to the output end of the single-phase conduction diode and the output end of the first digital-to-analog converter 6. The output value of the first digital-to-analog converter 6 is amplified and output in proportion through the second amplifier.

[0044] The circuit diagram of the clamping system according to the embodiment of the present invention is as Figure 3 shown. When the joint 3 of the switch S1 in the figure is connected to the joint 2, the joint 1 and the joint 2 of the switch S2 are connected, and the joint 1 and the joint 4 of the switch S3 are disconnected, the clamping system of this embodiment can be used to clamp the output of the voltage source. When the joint 1 of the switch S1 is connected to the joint 2, the joint 3 and the joint 2 of the switch S2 are connected, and the joint 1 and the joint 4 of the switch S3 are connected, the clamping system of this embodiment can be used to clamp the output of the current source.

[0045] The embodiment of the present invention also provides a clamping method. Based on the clamping system provided by the above embodiment and the preferred embodiment, the clamping method includes the following steps:

[0046] Step 10): Determine n test theoretical values, and obtain n test first preset values and n test second preset values according to the test theoretical values; n represents an integer greater than or equal to 2;

[0047] Step 20): Sequentially set n test first preset values in the first digital-to-analog converter 6, sequentially set n test second preset values in the second digital-to-analog converter 7, and measure the output end of the main circuit output circuit 4 to obtain n actual output values;

[0048] Step 30): According to the test theoretical values and the actual output values, obtain a correction model as shown in Equation (1):

[0049] Y = AX + B Equation (1)

[0050] In the formula, Y represents the theoretical output value, X represents the actual output value, A represents the first coefficient, and B represents the second coefficient;

[0051] Step 40) Through the correction model, obtain the theoretical output value according to the expected output value, obtain the first preset value and the second preset value according to the theoretical output value, set the first preset value in the first digital-to-analog converter 6, and set the second preset value in the second digital-to-analog converter 7.

[0052] In the clamping method of this embodiment, considering the output deviation of the system, different theoretical output values are set, the actual output value is measured, and the correction model is obtained according to the theoretical output value and the actual output value. Using the correction model, the theoretical output value can be obtained according to the expected output value, and then the first preset value and the second preset value can be obtained, so as to correct the first preset value set in the first digital-to-analog converter 6 and the second preset value set in the second digital-to-analog converter 7, that is, correct the output values of the first digital-to-analog converter 6 and the second digital-to-analog converter 7, make the output values of the first digital-to-analog converter 6 and the second digital-to-analog converter 7 more accurate, reduce the system output deviation, and improve the clamping accuracy.

[0053] When the clamping system of this embodiment is used to clamp the output of the current source, determine n test theoretical current values, obtain n test first preset values and n test second preset values according to the test theoretical current values, set the n test first preset values respectively through the first digital-to-analog converter 6, set the n test second preset values respectively through the second digital-to-analog converter 7, measure n actual output voltage values with a multimeter, and obtain n actual output current values according to I (actual output current value) = U (actual output voltage value) / R (resistance value of the detection resistor). According to the test theoretical current value and the actual output current value, obtain the correction model: Y = AX + B. According to the expected output current value and the correction model, obtain the theoretical output current value, and obtain the first preset value and the second preset value according to the theoretical output current value, and set them respectively through the first digital-to-analog converter 6 and the second digital-to-analog converter 7.

[0054] When the clamping system of this embodiment is used to clamp the output of the voltage source, determine n test theoretical voltage values, obtain n test first preset values and n test second preset values according to the test theoretical voltage values, set the n test first preset values respectively through the first digital-to-analog converter 6, set the n test second preset values respectively through the second digital-to-analog converter 7, and measure n actual output voltage values with a multimeter. According to the test theoretical voltage value and the actual output voltage value, obtain the correction model: Y = AX + B. Through the correction model, obtain the theoretical output voltage value according to the expected output voltage value, obtain the first preset value and the second preset value according to the theoretical output voltage value, and set them respectively through the first digital-to-analog converter 6 and the second digital-to-analog converter 7.

[0055] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above specific embodiments, and the above specific embodiments and the description in the specification are only for further explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the claims and their equivalents.

Claims

1. A clamping system, characterized in that, it includes a differential operational amplifier (1), a compensation operational amplifier (2), a unidirectional conduction diode (3), a main circuit output circuit (4) and a acquisition circuit (5). The output end of the differential operational amplifier (1) is connected to the input end of the compensation operational amplifier (2). The output end of the compensation operational amplifier (2) is connected to one end of the unidirectional conduction diode (3). The other end of the unidirectional conduction diode (3) is connected to the reverse input end of the compensation operational amplifier (2). The other end of the unidirectional conduction diode (3) is connected to the input end of the main circuit output circuit (4). The input end of the acquisition circuit (5) is connected to the output end of the main circuit output circuit (4). The output end of the acquisition circuit (5) is connected to the input end of the differential operational amplifier (1); it further includes a first digital-to-analog converter (6) and a second digital-to-analog converter (7). The output end of the first digital-to-analog converter (6) is connected to the input end of the main circuit output circuit (4). The output end of the second digital-to-analog converter (7) is connected to the input end of the differential operational amplifier (1).

2. The clamping system according to claim 1, characterized in that, it further includes a calibration measurement module (8), and the calibration measurement module (8) is connected to the output end of the main circuit output circuit (4).

3. The clamping system according to claim 2, characterized in that, it further includes an operation module (10) and a data communication module (11). The input end of the operation module (10) is connected to the output end of the calibration measurement module (8). The output end of the operation module (10) is connected to the input end of the data communication module (11). The output end of the data communication module (11) is respectively connected to the input end of the first digital-to-analog converter (6) and the input end of the second digital-to-analog converter (7).

4. The clamping system according to claim 2, characterized in that, the calibration measurement module (8) includes a measuring instrument.

5. The clamping system according to claim 4, characterized in that, the calibration measurement module (8) further includes a detection resistor. The detection resistor is connected in series at the output end of the main circuit output circuit (4). The measuring instrument is connected in parallel at both ends of the detection resistor.

6. The clamping system according to claim 1, characterized in that, the acquisition circuit (5) includes a first amplifier. The input end of the first amplifier is connected to the output end of the main circuit output circuit (4). The output end of the first amplifier is connected to the input end of the differential operational amplifier (1).

7. The clamping system according to claim 1, characterized in that, the main circuit output circuit (4) includes a second amplifier. The input end of the second amplifier is respectively connected to the output end of the unidirectional conduction diode (3) and the output end of the first digital-to-analog converter (6).

8. A clamping method, characterized in that, based on the clamping system according to any one of claims 1-7, the clamping method includes the following steps: Step 10) Determine n test theoretical values, and obtain n test first preset values and n test second preset values according to the test theoretical values; n represents an integer greater than or equal to 2; Step 20) Set n test first preset values in the first digital-to-analog converter (6) in sequence, set n test second preset values in the second digital-to-analog converter (7) in sequence, measure the output terminal of the main loop output circuit (4), and obtain n actual output values; Step 30) According to the test theoretical values and the actual output values, obtain a correction model as shown in Equation (1): Y = AX + B Equation (1) In the formula, Y represents the theoretical output value, X represents the actual output value, A represents the first coefficient, and B represents the second coefficient; Step 40) Through the correction model, obtain the theoretical output value according to the expected output value, obtain the first preset value and the second preset value according to the theoretical output value, set the first preset value in the first digital-to-analog converter (6), and set the second preset value in the second digital-to-analog converter (7).

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