A voltage monitoring device

Abstract

The present application discloses a voltage monitoring device, which includes two comparators. The threshold value corresponding to each comparator can be controlled and adjusted by a controller. The threshold values of the two comparators are different, so the results output by the two comparators are also different. The two comparators respectively detect whether the voltage exceeds its corresponding threshold value and output a comparison result. The controller can obtain the voltage monitoring result according to the comparison results of the two comparators. The information prompting unit can prompt the voltage monitoring result. The solution of the present application makes the voltage monitoring solution have lower cost, simpler circuit and higher monitoring accuracy.

Description

Technical Field

[0001] This application relates to the fields of electric power and electronic measurement, and particularly to a voltage monitoring device. Background Art

[0002] In devices or systems applied in various fields, it is often necessary to monitor voltage signals to determine whether the voltage is too high or whether voltage mutations (such as rapidly changing voltage surges) occur, which may damage the devices or systems. The fields involved include voltage mutation monitoring in power electronic systems, voltage dips in power lines, lightning strikes, surge monitoring, automotive igniters, electrocardiogram signal monitoring, acoustic emission (AE) monitoring (such as ultrasonic waves and stress waves), partial discharge monitoring, overshoot and ringing detection in electronic circuits, etc.

[0003] Most of the existing voltage monitoring devices adopt high-speed sampling and AD conversion technologies, but they face problems such as high cost and large high-frequency interference.

[0004] Taking the motor drive system as an example, variable frequency drive technology has been increasingly applied. The variable frequency drive technology adopts DC / AC conversion technology, and the traveling wave reflection and switching harmonics of the PWM voltage wave output by the frequency converter will generate strong voltage spikes. Currently, the common practice is to add a filter at the output end of the converter to reduce the overvoltage and harmonics generated on the motor side, thereby ensuring the safe and reliable operation of the motor. Here, the voltage is a PWM wave with large harmonics and a fast voltage rise rate, which has a large impact on resistors and capacitors, and the filter is prone to failure, thus affecting the safety and life of the motor. Monitoring the voltage peak applied to the filter and the voltage impact (voltage change rate) can determine the health status of the filter and predict its life.

[0005] To accurately monitor voltage signals, the existing technology needs to adopt a high-speed AD converter to adapt to the high-speed changes of the spikes. This increases the device cost and requires more complex peripheral circuits for support, resulting in problems such as electromagnetic noise emission. Therefore, the existing methods for monitoring voltage need to be further improved. Summary of the Invention

[0006] Many application scenarios are concerned with voltage peaks and voltage impacts (voltage change rates), and do not require measuring the voltage at all times. The functions of high-speed sampling and AD conversion in the existing technology are redundant. The technical problem to be solved by this application is the problems of high cost, complex circuit, and much electromagnetic noise existing in the existing voltage monitoring solutions. Therefore, in view of the above technical problems, this application provides a voltage monitoring device, including:

[0007] A controller;

[0008] A signal processing circuit that receives a voltage signal and preprocesses the voltage signal; the voltage signal is: a voltage signal across the component to be monitored, or a voltage signal obtained by adaptively converting other measured signals of the component to be monitored, and the measured signals include but are not limited to current signals, pulse signals, and ultrasonic signals;

[0009] A first comparator, whose first terminal is connected to the output terminal of the signal processing circuit and receives the preprocessed voltage signal;

[0010] A second comparator, whose first terminal is connected to the output terminal of the signal processing circuit and receives the preprocessed voltage signal;

[0011] A threshold adjustment unit, whose first terminal is connected to the output terminal of the controller, whose second terminal is connected to the second terminal of the first comparator, and whose third terminal is connected to the second terminal of the second comparator; the threshold adjustment unit outputs a threshold adjustment signal under the control of the controller to adjust the first threshold of the first comparator and the second threshold of the second comparator;

[0012] The controller is further configured to receive the comparison results of the first comparator and the second comparator, and obtain a voltage monitoring result according to the comparison results of the first comparator and the second comparator;

[0013] An information prompting unit, connected to the controller, for prompting the voltage monitoring result.

[0014] In some embodiments, the provided voltage monitoring device, the voltage monitoring result includes a voltage change rate and / or a voltage peak value.

[0015] In some embodiments, the provided voltage monitoring device, the controller determines a first time node when the voltage rises to the first threshold, a second time node when the voltage rises to the second threshold, a third time node when the voltage drops to the second threshold, and a fourth time node when the voltage drops to the first threshold according to the comparison results of the first comparator and the second comparator, and obtains a predicted peak value of the voltage signal according to the first threshold, the first time node and the fourth time node, the second threshold, and the second time node and the third time node;

[0016] The information prompting unit is further configured to prompt the predicted peak value.

[0017] In some embodiments, the provided voltage monitoring device, the controller obtains the predicted peak value according to the first threshold, the first time node and the fourth time node, the second threshold, and the second time node and the third time node by using a method of estimating the peak value by linear intersection or a method of estimating the peak value by curve fitting.

[0018] In some embodiments, a voltage monitoring device is provided. The controller determines the final predicted peak value according to the average value of the predicted peak values of the voltage obtained by at least two measurement methods.

[0019] In some embodiments, a voltage monitoring device is provided. The controller obtains the time when the voltage signal first rises to the first threshold as the monitoring start time, and obtains the time when the voltage signal last rises to the first threshold as the monitoring end time; obtains multiple peak values in the voltage signal detected during the monitoring period, takes the maximum peak value as the voltage peak value, and obtains the maximum amplitude moment corresponding to the voltage peak value.

[0020] The controller is further configured to obtain the voltage rising change rate during the monitoring period according to the monitoring start time, the maximum peak value moment, the first threshold, and the voltage peak value, and obtain the voltage falling change rate during the monitoring period according to the maximum peak value moment, the monitoring end time, the voltage peak value, and the first threshold.

[0021] The information prompting unit is further configured to prompt the voltage rising change rate, the voltage falling change rate, and the voltage peak value.

[0022] In some embodiments, a voltage monitoring device is provided. The controller is further configured to obtain the envelope of the voltage signal according to the voltage peak value, the maximum peak value moment, the monitoring start time, the monitoring end time, and the first threshold within a plurality of consecutive monitoring periods.

[0023] The information prompting unit is further configured to prompt the envelope.

[0024] In some embodiments, a voltage monitoring device is provided. The controller is further configured to obtain the voltage curve during the monitoring period according to the monitoring start time, the maximum peak value moment, the first threshold, and the voltage peak value; predict the voltage peak value of the next monitoring period according to the voltage curves of the current monitoring period and the previous plurality of monitoring periods.

[0025] The information prompting unit is further configured to prompt the voltage peak value of the next monitoring period.

[0026] In some embodiments, for a periodic voltage signal, the controller obtains the voltage peak value in the following manner:

[0027] S11: Obtain the first threshold and the second threshold; if in the first round:

[0028] The comparison result of the first comparator indicates that the voltage signal passes through the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal does not pass through the second threshold; and the difference between the second threshold and the first threshold is greater than or equal to the allowable error range, then execute step S12.

[0029] The comparison result of the first comparator indicates that the voltage signal experiences the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal experiences the second threshold twice. The difference between the second threshold and the first threshold is greater than or equal to the allowable error range; then step S13 is executed;

[0030] The comparison result of the first comparator indicates that the voltage signal experiences the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal does not experience the second threshold. The difference between the second threshold and the first threshold is less than the allowable error range, then step S14a is executed;

[0031] The comparison result of the first comparator indicates that the voltage signal experiences the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal experiences the second threshold twice. The difference between the second threshold and the first threshold is less than the allowable error range, then step S14b is executed;

[0032] S12: Keep the first threshold unchanged within the second round, and at the same time lower the second threshold to half of the sum of the first threshold and the second threshold in step S11; then return to step S11;

[0033] S13: Increase the first threshold to the second threshold in step S11 within the second round, and at the same time increase the second threshold; then return to step S11;

[0034] S14a: Obtain the voltage peak value according to the first threshold;

[0035] S14b: Obtain the voltage peak value according to the second threshold.

[0036] In some embodiments, the provided voltage monitoring device, the controller determines the first threshold and the second threshold within the first round according to the predicted peak value.

[0037] In some embodiments, the provided voltage monitoring device, the threshold adjustment unit includes a first adjustable resistor and a second adjustable resistor. The voltage across the first adjustable resistor is used as the adjusted first threshold; the voltage across the second adjustable resistor is used as the adjusted second threshold; the controller adjusts the resistance value of the first adjustable resistor to adjust the first threshold; the controller adjusts the resistance value of the second adjustable resistor to adjust the second threshold.

[0038] In some embodiments, the provided voltage monitoring device, the threshold adjustment unit includes a first dynamic voltage regulation chip and a second dynamic voltage regulation chip, the output voltage of the first dynamic voltage regulation chip is used as the first threshold, and the output voltage of the second dynamic voltage regulation chip is used as the second threshold; the controller adjusts the reference voltage in the first dynamic voltage regulation chip to adjust the output voltage of the first dynamic voltage regulation chip; the controller adjusts the reference voltage in the second dynamic voltage regulation chip to adjust the output voltage of the second dynamic voltage regulation chip.

[0039] In some embodiments, the provided voltage monitoring device, the threshold adjustment unit includes a first chopper circuit and a second chopper circuit, the voltage at the output terminal of the first chopper circuit is used as the first threshold, and the voltage at the output terminal of the second chopper circuit is used as the second threshold, the controller adjusts the PWM input pulse signal of the first chopper circuit to adjust the voltage at the output terminal of the first chopper circuit; the controller adjusts the PWM input pulse signal of the second chopper circuit to adjust the voltage at the output terminal of the second chopper circuit.

[0040] The technical solution of the present application has the following technical effects compared with the prior art:

[0041] The voltage monitoring device provided by the present application includes two comparators. The threshold corresponding to each comparator can be controlled and adjusted by the controller. The thresholds of the two comparators are different, so the results output by the two comparators are also different. The two comparators respectively detect whether the voltage exceeds its corresponding threshold and output the comparison results. The controller can obtain the voltage monitoring result based on the comparison results of the two comparators. The information prompt unit can prompt the voltage monitoring result to other devices that need to use the voltage monitoring result. The above solution of the present application can achieve accurate measurement of the voltage monitoring result, and does not require high-cost devices and complex peripheral circuits. Therefore, it can reduce the cost of the voltage monitoring device and avoid introducing unnecessary electromagnetic noise. Description of the Drawings

[0042] The following will describe in detail the preferred embodiments of the present application through the drawings, which will help to understand the purpose and advantages of the present application, where:

[0043] Figure 1 is a schematic diagram of the internal structure of the voltage monitoring device according to an embodiment of the present application;

[0044] Figure 2 is a waveform comparison diagram of voltage threshold comparison and comparator inversion time node recording according to an embodiment of the present application;

[0045] Figure 3 is a flowchart of the calculation process of the voltage rise rate and the voltage drop rate according to an embodiment of the present application;

[0046] Figure 4a Schematic diagram of estimating voltage peak using linear intersection method for an embodiment of the present application;

[0047] Figure 4b Schematic diagram of estimating voltage peak using curve fitting method for an embodiment of the present application;

[0048] Figure 5 Circuit diagram of adjustable reference voltage realized by adjustable resistor for an embodiment of the present application;

[0049] Figure 6 Circuit diagram of adjustable reference voltage realized by PWM voltage regulation and analog voltage regulation circuits using BUCK circuit for an embodiment of the present application;

[0050] Figure 7a and Figure 7b Circuit diagram of adjustable reference voltage realized by using dynamic voltage regulation chip for an embodiment of the present application;

[0051] Figure 8 Schematic diagram of peak approximation algorithm for an embodiment of the present application;

[0052] Figure 9 Schematic diagram of multi-peak voltage curve for an embodiment of the present application;

[0053] Figure 10 is Figure 9 Schematic diagram of approximation algorithm in the case of multi-peak shown;

[0054] Figure 11 Schematic diagram of the principle of obtaining voltage change rate by dividing monitoring time period for an embodiment of the present application. Detailed implementation manners

[0055] Next, the technical solutions of the present application will be described clearly and completely with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0056] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0057] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0058] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0059] The voltage monitoring device provided in the following embodiments of the present application can be applied to various scenarios, such as voltage mutation monitoring of power electronic systems, voltage dips of power lines, lightning strikes, surge monitoring, automotive igniters, electrocardiogram signal monitoring, acoustic emission (AE) monitoring: such as ultrasonic, stress wave, partial discharge (PD) monitoring, overshoot and ringing detection of electronic circuits, etc. Therefore, the voltage signal described in the following embodiments of the present application can be the voltage signal across the monitored component, or the voltage signal obtained by adaptively converting other measured signals of the monitored component, and the measured signals include but are not limited to current signals, pulse signals, and ultrasonic signals.

[0060] This embodiment provides a voltage monitoring device, such as Figure 1 , the voltage monitoring device includes a signal processing circuit 101, which may include a preprocessing circuit, a conditioning circuit, etc., a first comparator 102, a second comparator 103, a threshold adjustment unit 104, a controller 105, and an information prompt unit 106. The signal processing circuit 101 receives the voltage signal (such as the input terminal of the voltage signal in the figure), preprocesses the voltage signal, and the preprocessed voltage signal is input to the first terminal of the first comparator 102 and the first terminal of the second comparator  103; the second terminal of the first comparator 102 and the second terminal of the second comparator 103 are connected to the output terminal of the threshold adjustment unit 104, and the threshold adjustment unit 104 adjusts the first threshold input to the first comparator 102 and the second threshold input to the second comparator 103 under the control of the controller 105; the controller 105 is further configured to receive the comparison results output by the first comparator 102 and the second comparator 103, and the controller 105 obtains a voltage monitoring result according to the comparison results of the first comparator 102 and the second comparator 103. The information prompt unit 106 is connected to the controller 105 to prompt the voltage monitoring result.

[0061] In specific implementation, the voltage monitoring result is determined according to actual needs, which may include the voltage change rate, or may include the voltage peak value, or may include both the voltage change rate and the voltage peak value, etc. In the above solution, two comparators with adjustable thresholds are provided. The threshold corresponding to each comparator can be controlled and adjusted by the controller. The thresholds of the two comparators are different, so the results output by the two comparators are also different. The two comparators respectively detect whether the voltage exceeds their corresponding thresholds and output comparison results. The controller can obtain the voltage monitoring result based on the comparison results of the two comparators. The information prompt unit can prompt the voltage monitoring result to other devices that need to utilize the voltage monitoring result. The above solution of the present application can achieve accurate measurement of the voltage monitoring result and does not require high-cost devices and complex peripheral circuits, so the cost and noise of the voltage monitoring device can be reduced.

[0062] Specifically, as Figure 2 and Figure 3 shown, it is a schematic diagram of the voltage change rate measurement steps. First, set the first threshold of the first comparator 102 to Uth1, and set the second threshold of the second comparator 103 to Uth2. When the voltage rises, at the time node Trs1, the first comparator 102 changes its state, for example, the output changes from low level to high level; at the time node Trs2, the second comparator 103 changes its state, for example, the output changes from low level to high level. When the voltage drops, at the time node Tfa2, the second comparator 103 changes its state, and the output changes from high level to low level; at the time node Tfa1, the first comparator 102 changes its state, and the output changes from high level to low level. The controller 105 respectively records the above time nodes Trs1, Trs2, Tfa2, and Tfa1, and calculates the rising change rate and the falling change rate of the voltage through the following formulas. The calculation formulas are respectively: rising change rate = (Uth2 - Uth1) ÷ (Trs2 - Trs1); falling change rate = (Uth2 - Uth1) ÷ (Tfa2 - Tfa1).

[0063] In the above solution provided by this embodiment, the controller 105 can obtain the voltage change rate based on the comparison results of the two comparators. The information prompt unit 106 can send the voltage change rate to any device that needs this information, providing technical data for other devices. Compared with the prior art, the monitoring device in this solution can obtain the voltage change rate with a low-complexity and low-cost structure, realizing accurate measurement of the voltage change rate. In the above solution of the present application, the implementation process of the solution is described by taking two comparators as an example. However, in actual application, the number of comparators can be increased according to the application scenario, but the working principle of each comparator is the same as that of the comparator in this embodiment.

[0064] It can be understood that in the signal processing circuit, existing circuits can be selected as needed, such as a sampling circuit, a noise reduction circuit, a signal conditioning and amplification circuit, etc.

[0065] In the above solution of the present application, the controller 105 is further configured to determine a first time node when the voltage rises to the first threshold, a second time node when the voltage rises to the second threshold, a third time node when the voltage drops to the second threshold, and a fourth time node when the voltage drops to the first threshold according to the comparison result of the first comparator 102, and obtain a predicted peak value of the voltage signal according to the first threshold, the first time node and the fourth time node, the second threshold, and the second time node and the third time node; the information prompt unit 106 is further configured to prompt the predicted peak value. In specific implementation, the voltage may have situations such as rising, falling, positive, and negative values. Although the rising and falling in the case of positive values are taken as examples in this embodiment for illustration, those skilled in the art can Figure 2 and Figure 3 derive the judgment process of rising and falling in the case of negative values according to the records of.

[0066] As Figure 4a shown, in some embodiments, the controller 105 uses the method of linear intersection to estimate the peak value to obtain the predicted peak value of the voltage according to the first threshold Uth1, the time nodes Trs1 and Tfa1 corresponding to the first threshold Uth1, the second threshold Uth2, and the time nodes Trs2 and Tfa2 corresponding to the second threshold Uth2; two data points can determine a straight line. During the voltage rising process and the falling process, two data points can be determined according to the first threshold Uth1, the time nodes Trs1 and Tfa1, the second threshold Uth2, and the time nodes Trs2 and Tfa2. The slope of the rising edge can be fitted by a straight line through "Uth1 / Trs1" and "Uth2 / Trs2"; the slope of the falling edge can be fitted by a straight line through "Uth2 / Tfa2" and "Uth1 / Tfa1". The intersection point of the two straight lines is close to the actual peak value of the waveform and can be used to estimate the peak value.

[0067] As Figure 4bAs another solution, as shown in the figure, the controller 105 obtains the predicted peak value of the voltage by using the method of curve fitting to estimate the peak value according to the first threshold Uth1, Trs1 and Tfa1 corresponding to the first threshold Uth1, the second threshold Uth2, and time nodes Trs2 and Tfa2 corresponding to the second threshold Uth2; according to the first threshold Uth1, the time nodes Trs1 and Tfa1, the second threshold Uth2, and the time nodes Trs2 and Tfa2, four points on the voltage curve are obtained. Then, according to the existing curve fitting algorithm, the voltage curve can be fitted by using the above four points or any three of them, and the predicted peak value of the voltage can be obtained naturally after obtaining the voltage curve.

[0068] In addition, the present application can also obtain the predicted peak value of the voltage in other ways. In specific implementation, the controller 105 can also determine the final predicted peak value according to the average value of the predicted peak values of the voltage signals obtained by at least two measurement methods. That is, the predicted peak value of the voltage signal can be obtained according to multiple measurement methods, and the average value is calculated and used as the final predicted peak value after obtaining the average value to improve the measurement accuracy.

[0069] For some situations where the accuracy requirement for the voltage peak value is not high or the voltage signal is an aperiodic signal, the voltage peak value predicted by the above method can meet the requirements. In this solution, the voltage peak value can be obtained, and when there is a risk of damaging the device or system, the damage degree can be estimated according to the voltage peak value.

[0070] In some solutions, as Figure 5 shown, the threshold adjustment unit 104 includes a first adjustable resistor and a second adjustable resistor. The voltage across the first adjustable resistor is used as the adjusted first threshold; the voltage across the second adjustable resistor is used as the adjusted second threshold; the controller 105 adjusts the resistance value of the first adjustable resistor to adjust the first threshold; the controller 105 adjusts the resistance value of the second adjustable resistor to adjust the second threshold. Figure 5 Taking the adjustment of the first threshold of the first comparator 102 as an example for illustration, the threshold adjustment unit 104 can be implemented by using, for example, MAXIM5432 and MAXIM6160. It receives the first threshold adjustment instruction given by the controller 105 through the SDA and SCL of MAXIM5432 to adjust its resistance value; and controls the ADJ of MAXIM6160 through W to achieve the effect of adjusting the output voltage V0.

[0071] In another example, as Figure 6As shown in the figure, the threshold adjustment unit 104 includes a first chopper circuit and a second chopper circuit. The voltage at the output terminal of the first chopper circuit serves as the first threshold, and the voltage at the output terminal of the second chopper circuit serves as the second threshold. The controller 105 adjusts the PWM input pulse signal of the first chopper circuit to adjust the voltage at the output terminal of the first chopper circuit; the controller 105 adjusts the PWM input pulse signal of the second chopper circuit to adjust the voltage at the output terminal of the second chopper circuit. As Figure 6 shown, a PWM voltage regulation circuit using a BUCK circuit is used to implement a reference voltage adjustable circuit, and a scheme for adjusting the reference voltage is given. In the adjustment circuit shown in the figure, VPWM receives the PWM signal given by the controller unit. By changing the input of VPWM, the output voltage (VOUT) of the XL4013 and its peripheral circuits can be made variable, achieving the effect of adjusting the output voltage.

[0072] In another example, as Figure 7a and 7b shown, the threshold adjustment unit 104 includes a first dynamic voltage regulation chip and a second dynamic voltage regulation chip. The output voltage of the first dynamic voltage regulation chip serves as the first threshold, and the output voltage of the second dynamic voltage regulation chip serves as the second threshold; the controller 105 adjusts the reference voltage inside the first dynamic voltage regulation chip to adjust the output voltage of the first dynamic voltage regulation chip; the controller 105 adjusts the reference voltage inside the second dynamic voltage regulation chip to adjust the output voltage of the second dynamic voltage regulation chip; TPS546C23 can be selected as the dynamic voltage regulation chip, as Figure 7a shown is the internal circuit structure schematic diagram of TPS546C23. TPS546C23 is a 4.5V to 18V synchronous buck converter with PMBus. The output voltage of the chip supporting PMBus can be set through the VOUT_COMMAND register. TPS546C23 receives the voltage command given by the controller, achieving the effect of adjusting the output voltage.

[0073] In the above scheme, the threshold voltage adjustment unit can receive the instruction of the controller 105 to adjust the voltage of Uth1 to make it closer to the top of the curve, achieving the effect of improving the peak measurement accuracy. Among them, the threshold adjustment method of one of the comparators is taken as an example for illustration. It can be understood that in actual applications, the threshold adjustment for different comparators can refer to the adjustment methods in the above examples.

[0074] Preferably, in the above scheme, for a periodic voltage signal, the controller 105 obtains the voltage peak through the following method:

[0075] S11: Obtain the first threshold and the second threshold. Here, the first threshold and the second threshold can be arbitrarily selected within the measurement range.

[0076] If within the first round:

[0077] The comparison result of the first comparator indicates that the voltage signal has passed through the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal has not passed through the second threshold (such as Figure 8 Round1 and Round3 in the figure), and the difference between the second threshold and the first threshold is greater than or equal to the allowable error range; then step S12 is executed;

[0078] The comparison result of the first comparator indicates that the voltage signal has passed through the first threshold twice, and the comparison result of the second comparator indicates that the voltage signal has passed through the second threshold twice (such as Figure 8 Round2 and Round4 in the figure); and the difference between the second threshold and the first threshold is greater than or equal to the allowable error range, then step S13 is executed;

[0079] The comparison result of the first comparator indicates that the voltage signal has passed through the first threshold twice, the comparison result of the second comparator indicates that the voltage signal has not passed through the second threshold, and the difference between the second threshold and the first threshold is less than the allowable error range, then step S14a is executed;

[0080] The comparison result of the first comparator indicates that the voltage signal has passed through the first threshold twice, the comparison result of the second comparator indicates that the voltage signal has passed through the second threshold twice; the difference between the second threshold and the first threshold is less than the allowable error range (such as Figure 8 Round5 in the figure), then step S14b is executed;

[0081] S12: Keep the first threshold unchanged in the second round, and at the same time lower the second threshold to half of the sum of the first threshold and the second threshold in step S11; then return to step S11;

[0082] S13: In the second round, raise the first threshold to the second threshold in step S11, and at the same time raise the second threshold; make the raised second threshold higher than the second threshold in step S11 and less than the second threshold that has not been passed through by the voltage signal in the previous round, then return to step S11;

[0083] S14a: Obtain the voltage peak according to the first threshold; at this time, the voltage peak is between the first threshold and the second threshold.

[0084] S14b: Obtain the voltage peak according to the second threshold; at this time, the second threshold is closer to the voltage peak, and the voltage peak is slightly higher than the second threshold.

[0085] Specifically, refer to Figure 8As shown, first, arbitrarily select a first threshold Uth1 and a second threshold Uth2 within the range. Then perform the following:

[0086] Round1: In the round of the first threshold changing from low → high → low, if the second threshold Uth2 remains unchanged, at this time, Uth1 and Uth2 are represented by Uth1(R1) and Uth2(R1) respectively.

[0087] Round2: Keep the first threshold Uth1 unchanged, Uth1(R2) = Uth1(R1), Uth2(R2) = [Uth2(R1) - Uth1(R1)] / 2 + Uth1(R1). In the round of the first threshold Uth1 changing from low → high → low, if the second threshold Uth2 also changes from low → high → low, enter Round3.

[0088] Round3: Uth1(R3) = Uth2(R2), Uth2(R3) = [Uth2(R1) - Uth2(R2)] / 2 + Uth2(R2). In the round of the first threshold Uth1 changing from low → high → low, if the second threshold Uth2 remains unchanged, enter Round4.

[0089] Round4: Keep the first threshold Uth1 unchanged, Uth1(R4) = Uth1(R3), Uth2(R4) = [Uth2(R3) - Uth1(R3)] / 2 + Uth1(R3). In the round of the first threshold Uth1 changing from low → high → low, if the second threshold Uth2 also changes from low → high → low, enter Round5.

[0090] Round5: Uth1(R5) = Uth2(R4), Uth2(R5) = [Uth2(R3) - Uth2(R4)] / 2 + Uth2(R4). In the round of the first threshold Uth1 changing from low → high → low, if the second threshold Uth2 also changes from low → high → low, and Uth2 - Uth1 is less than the allowable error range, then Uth2 can be determined; otherwise, enter the next round according to the same rule.

[0091] Obviously, after multiple rounds of threshold adjustment, either the first threshold or the second threshold can be very close to the peak value. At this time, the difference between the first threshold and the second threshold is less than the allowable error range. Then, the voltage peak value can be obtained based on either the first threshold or the second threshold. The measurement error of this voltage peak value is less than the allowable error range, meeting the requirements of measurement accuracy.

[0092] Further, the controller 105 can also determine a first threshold and a second threshold within the first round according to the predicted peak value, thereby reducing the time required for the peak value to approach, and enabling the first threshold to approach the voltage peak value more quickly.

[0093] For the case of multiple peaks as Figure 9 shown, refer to the Figure 10 table shown. For the scenario of multiple peaks, the aforementioned threshold approximation process is equally effective. Figure 10 Taking the case where the two peaks are lower in the front and higher in the back in Figure 10 as an example, other multiple-peak cases are similar and will not be elaborated further. As Figure 10 shown, when the first threshold Uth1 and the second threshold Uth2 respectively select different threshold combinations, there are 6 permutations and combinations in the table. Among them, Trs1-A represents "peak A rising edge threshold 1", and Tfa2-B represents "peak B falling edge threshold 2"; "↑" indicates a rising edge change, "↓" indicates a falling edge change, and " / " indicates no change. Taking as a complete round and processing according to the rules of S12 described above, scenarios 4, 5, and 6 can all normally complete the peak value approximation. Although scenario 1 contains two peaks, it meets the conditions of the complete round and is processed according to the rules of S12 described above, and finally the peak value approximation can also be completed. The same is true for scenario 3. Although the low → high → low change round of Trs1 contains two peaks and is processed according to the rules of S12 described above, the peak value approximation can finally be completed. In scenario 2, Trs2 (Uth2) changes twice during the low → high → low change round of Trs1 (Uth1). By combining the two changes, it can also be processed according to the rules of S12 described above, and finally the peak value approximation is completed.

[0094] In the solutions of the above embodiments of the present application, when measuring the voltage signal, two or more comparators are used (multiple comparators can improve the effect of curve fitting; can simultaneously detect the over-threshold phenomenon of multiple peaks; can simultaneously support more threshold detections).

[0095] The above solutions can be applied to the application scenario of measuring "‘burst-type’ standard acoustic emission signals" and performing stress wave analysis using the "acoustic emission parameter analysis method". In the above scenario, when the acoustic signal emitted by the acoustic emission source propagates to the material surface, the material will undergo mechanical vibration, and the mechanical vibration of the material can be converted into a voltage signal by a sensor, and then monitored by the voltage signal monitoring device in this solution. As Figure 11As shown, the controller 105 obtains the time when the voltage signal first rises to the first threshold Uth1 as the monitoring start time, and obtains the time when the voltage signal last rises to the first threshold Uth1 as the monitoring end time; obtains multiple peaks in the detected voltage signals during the monitoring period, and takes the maximum peak Uth2b as the voltage peak and obtains the maximum amplitude moment corresponding to the voltage peak; the controller 105 is further configured to obtain the voltage rise change rate during the monitoring period according to the monitoring start time, the maximum peak moment, the first threshold, and the voltage peak, and obtain the voltage drop change rate during the monitoring period according to the maximum peak moment, the monitoring end time, the voltage peak, and the first threshold; the information prompting unit 106 is further configured to prompt the voltage rise change rate, the voltage drop change rate, and the voltage peak. It can be understood that when using Uth1 as the first threshold according to the steps in the foregoing embodiments and using Uth2a as the second threshold, the change rate of the rise or fall of a single peak can be measured. And in this application, it is equivalent to monitoring across peaks, and the maximum peak Uth2b can be determined within a certain time interval. By the way of crossing multiple peaks, the "rise time" is measured, that is, the moment when Uth1 is first triggered and the moment of Uth2b. Further, the overall change rate of the rising interval (Uth2b - Uth1) / (Tth2b - Tth1) is determined. The same applies to the falling interval and will not be elaborated here.

[0096] Further, the controller 105 is further configured to obtain the envelope of the voltage signal according to the voltage peak, the maximum peak moment, the monitoring start time, the monitoring end time, and the first threshold in a plurality of consecutive monitoring periods; the information prompting unit 106 is further configured to prompt the envelope. The controller 105 is further configured to obtain the voltage curve during the monitoring period according to the monitoring start time, the maximum peak moment, the first threshold, and the voltage peak; predict the voltage peak of the next monitoring period according to the voltage curves of the current monitoring period and the previous plurality of monitoring periods; the information prompting unit 106 is further configured to prompt the voltage peak of the next monitoring period. After obtaining the envelope shape (voltage peak, rise change rate, fall change rate) during the monitoring period, the peak value of the curve shape of the next monitoring period can be deduced according to the curve shape mode, and each peak Uth2i (i represents a certain peak) therein is adjusted to the corresponding voltage level. Moreover, through the envelope curve shape of the current monitoring period and the envelope curve shape of the previous monitoring periods, the deduction accuracy can be further improved, and Uth2i can be better adapted to the next peak value.

[0097] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of this application.

Claims

1. A voltage monitoring device, characterized in that, Comprising: A controller; A signal processing circuit that receives a voltage signal and preprocesses the voltage signal; the voltage signal is: a voltage signal across the component to be monitored, or a voltage signal obtained by adaptively converting other measured signals of the component to be monitored, and the measured signals include but are not limited to current signals, pulse signals, and ultrasonic signals; A first comparator, whose first terminal is connected to the output terminal of the signal processing circuit and receives the preprocessed voltage signal; A second comparator, whose first terminal is connected to the output terminal of the signal processing circuit and receives the preprocessed voltage signal; A threshold adjustment unit, whose first terminal is connected to the output terminal of the controller, whose second terminal is connected to the second terminal of the first comparator, and whose third terminal is connected to the second terminal of the second comparator; the threshold adjustment unit outputs a threshold adjustment signal under the control of the controller to adjust the first threshold of the first comparator and the second threshold of the second comparator; The controller is further configured to receive the comparison results of the first comparator and the second comparator, and obtain a voltage monitoring result based on the comparison results of the first comparator and the second comparator; An information prompting unit, connected to the controller, and prompts the voltage monitoring result; The voltage monitoring result includes a voltage change rate and / or a voltage peak value; The controller determines a first time node when the voltage rises to the first threshold, a second time node when the voltage rises to the second threshold, a third time node when the voltage drops to the second threshold, and a fourth time node when the voltage drops to the first threshold according to the comparison results of the first comparator and the second comparator, and obtains a predicted peak value of the voltage signal based on the first threshold, the first time node and the fourth time node, the second threshold, and the second time node and the third time node; the information prompting unit is further configured to prompt the predicted peak value; or, The controller obtains the time when the voltage signal first rises to the first threshold as the monitoring start time, and obtains the time when the voltage signal last rises to the first threshold as the monitoring end time; obtains multiple peak values in the voltage signals detected during the monitoring period, and takes the maximum peak value as the voltage peak value and obtains the maximum amplitude moment corresponding to the voltage peak value; the controller is further configured to obtain a voltage rise change rate during the monitoring period based on the monitoring start time, the maximum peak value moment, the first threshold, and the voltage peak value, and obtain a voltage drop change rate during the monitoring period based on the maximum peak value moment, the monitoring end time, the voltage peak value, and the first threshold; the information prompting unit is further configured to prompt the voltage rise change rate, the voltage drop change rate, and the voltage peak value.

2. The voltage monitoring device according to claim 1, wherein: The controller obtains the predicted peak value by using a method of estimating the peak value by linear intersection or a method of estimating the peak value by curve fitting based on the first threshold, the first time node and the fourth time node, the second threshold, and the second time node and the third time node.

3. The voltage monitoring device according to claim 2, wherein: The controller determines the final predicted peak value according to the average value of the predicted peak values of the voltage obtained by at least two measurement methods.

4. The voltage monitoring device according to claim 1, wherein: The controller is further configured to obtain an envelope of the voltage signal according to the voltage peak value, the maximum peak time, the monitoring start time, the monitoring end time, and the first threshold value within a plurality of consecutive monitoring periods; The information prompting unit is further configured to prompt the envelope.

5. The voltage monitoring device according to claim 4, wherein: The controller is further configured to obtain a voltage curve within the monitoring period according to the monitoring start time, the maximum peak time, the first threshold value, and the voltage peak value; predict the voltage peak value of the next monitoring period according to the voltage curves of the current monitoring period and a plurality of previous monitoring periods; The information prompting unit is further configured to prompt the voltage peak value of the next monitoring period.

6. The voltage monitoring device according to any one of claims 1-3, wherein: For a periodic voltage signal, the controller obtains the voltage peak value in the following manner: S11: Obtain a first threshold value and a second threshold value; if within the first round: The comparison result of the first comparator indicates that the voltage signal passes through the first threshold value twice, and the comparison result of the second comparator indicates that the voltage signal does not pass through the second threshold value; and the difference between the second threshold value and the first threshold value is greater than or equal to the allowable error range, then perform step S12; The comparison result of the first comparator indicates that the voltage signal passes through the first threshold value twice, and the comparison result of the second comparator indicates that the voltage signal passes through the second threshold value twice, and the difference between the second threshold value and the first threshold value is greater than or equal to the allowable error range; then perform step S13; The comparison result of the first comparator indicates that the voltage signal passes through the first threshold value twice, and the comparison result of the second comparator indicates that the voltage signal does not pass through the second threshold value; If the difference between the second threshold value and the first threshold value is less than the allowable error range, then perform step S14a; The comparison result of the first comparator indicates that the voltage signal passes through the first threshold value twice, and the comparison result of the second comparator indicates that the voltage signal passes through the second threshold value twice; if the difference between the second threshold value and the first threshold value is less than the allowable error range, then perform step S14b; S12: Keep the first threshold value unchanged in the second round, and at the same time lower the second threshold value to half of the sum of the first threshold value and the second threshold value in step S11; then return to step S11; S13: Raise the first threshold value to the second threshold value in step S11 in the second round, and at the same time raise the second threshold value; then return to step S11; S14a: Obtain the voltage peak value according to the first threshold value; S14b: Obtain the voltage peak value according to the second threshold value.

7. The voltage monitoring device according to claim 6, wherein: The controller determines the first threshold value and the second threshold value in the first round according to the predicted peak value.

8. The voltage monitoring device according to claim 1, wherein: The threshold adjustment unit includes a first adjustable resistor and a second adjustable resistor. The voltage across the first adjustable resistor serves as the adjusted first threshold; the voltage across the second adjustable resistor serves as the adjusted second threshold. The controller adjusts the resistance value of the first adjustable resistor to adjust the first threshold. The controller adjusts the resistance value of the second adjustable resistor to adjust the second threshold.

9. The voltage monitoring device according to claim 1, wherein: The threshold adjustment unit includes a first dynamic voltage regulation chip and a second dynamic voltage regulation chip. The output voltage of the first dynamic voltage regulation chip serves as the first threshold, and the output voltage of the second dynamic voltage regulation chip serves as the second threshold. The controller adjusts the reference voltage in the first dynamic voltage regulation chip to adjust the output voltage of the first dynamic voltage regulation chip; the controller adjusts the reference voltage in the second dynamic voltage regulation chip to adjust the output voltage of the second dynamic voltage regulation chip.

10. The voltage monitoring device according to claim 1, wherein: The threshold adjustment unit includes a first chopper circuit and a second chopper circuit. The voltage at the output terminal of the first chopper circuit serves as the first threshold, and the voltage at the output terminal of the second chopper circuit serves as the second threshold. The controller adjusts the PWM input pulse signal of the first chopper circuit to adjust the voltage at the output terminal of the first chopper circuit; the controller adjusts the PWM input pulse signal of the second chopper circuit to adjust the voltage at the output terminal of the second chopper circuit.

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