Application of angle detection method

Abstract

The invention discloses an application of an angle detection method, and relates to the field of transformer substation pressure plate monitoring, the first step is that an acceleration sensor is installed on a pressure plate in a transformer substation protection tripping circuit, the second step is that a three-axis inclination angle is calculated through a digital filtering method, and the third step is that a three-axis acceleration value after amplitude limiting averaging is substituted into a calculation formula. Fourthly, the obtained x-axis inclination angle and y-axis inclination angle are calibrated, when the pressing plate rotates or generates angle inclination, the acceleration sensor and the pressing plate synchronously rotate and incline, the acceleration of the Z-axis of the acceleration sensor is kept unchanged, the resultant force direction of the acceleration of the X-axis and the Y-axis of the acceleration sensor is gravity after movement is stable, and the gravity direction of the acceleration of the X-axis and the Y-axis of the acceleration sensor is zero. At the moment, the acceleration of the acceleration sensor is gravitational acceleration, the acceleration sensor can be used for monitoring the inclination angle data of the pressing plate, the three-axis inclination angle is calculated through a digital filtering method, the three-axis inclination angle value is obtained through optimization, burrs of the acceleration value are reduced, and the data are more accurate.

Description

Technical Field

[0001] The invention relates to the field of transformer substation pressure plate monitoring, and in particular to the application of an angle detection method. Background Art

[0002] The pressure plate in the substation protection tripping circuit is the bridge and link connecting the external wiring, which is related to whether the protection function and action output can function normally. However, due to irregular operation, the pressure plate may be missed or misplaced sometimes. When the pressure plate is put into use, its status monitoring is also very important. The existing status monitoring equipment needs to replace the new pressure plate, which is not only troublesome but also costly.

[0003] Different from traditional acceleration sensors, MEMS acceleration sensors are micro systems that integrate micro sensors, micro actuators, signal processing circuits and communication interfaces. They are widely used in various fields due to their low cost, low power consumption, high reliability, easy integration and intelligence. Acceleration sensors can also be used to measure the inclination of the pressure plate in the protection tripping circuit of a substation.

[0004] However, due to the influence of factors such as the process level and the core sensor, the raw acceleration value output by the MEMS acceleration sensor is unstable and has many burrs. If the raw data is directly used, the obtained inclination value fluctuates greatly and has a high error.

[0005] Therefore, it is necessary to propose an angle detection method to solve the above problems.

[0006] content

[0007] The purpose of the present invention is to provide an application of an angle detection method to solve the problem that the original acceleration value output by the MEMS acceleration sensor is unstable and has many burrs due to the influence of factors such as the process level and the core sensor. If the original data is directly used, the obtained inclination value fluctuates greatly and has a high error.

[0008] To achieve the above object, the present invention provides the following technical solution: an application of an angle detection method, comprising the following steps:

[0009] The first step is to install the acceleration sensor on the pressure plate in the protection tripping circuit of the substation, and the acceleration sensor uses a micro-electromechanical system acceleration sensor;

[0010] The second step is to calculate the three-axis inclination angle through the digital filtering method. The digital filtering method collects the original acceleration data at a sampling frequency of 100 Hz and takes 1 Hz as the output frequency;

[0011] Digital filtering methods include:

[0012] Collect the original three-axis acceleration values, and perform first-order low-pass filtering on the x-axis, y-axis, and z-axis acceleration values ​​respectively;

[0013] For every 100 sampling points of the filtered three-axis acceleration values, perform a limited average.

[0014] Step 3: Substitute the three-axis acceleration values ​​after limiting and averaging into the calculation formula to calculate the x-axis angle and the y-axis angle, and obtain the x-axis inclination angle and the y-axis inclination angle respectively;

[0015] The calculation formula is as follows:

[0016]

[0017]

[0018]

[0019] Among them, angle x Indicates the offset angle between the x-axis and the horizontal plane, angle y Indicates the offset angle between the y-axis and the horizontal plane, angle z Indicates the offset angle between the z-axis and the horizontal plane, a x represents the component of acceleration on the x-axis, a y represents the component of acceleration on the y-axis, a z represents the component of acceleration on the z-axis, tanh represents the inverse tangent function, and pi represents pi;

[0020] Step 4: Calibrate the obtained x-axis inclination angle and y-axis inclination angle, take the previous x average angle data of the acceleration sensor as the initial reference value, and the calibration angle is equal to the current angle.

[0021] Preferably, the first-order low-pass filtering algorithm formula is as follows:

[0022] Y(n)=αX(n)+(1-α)Y(n-1)

[0023] Among them, α is the filter coefficient, X(n) is the current sample sampling value, Y(n-1) is the previous filter output value, and Y(n) is the current filter output value.

[0024] Preferably, the first-order low-pass filtering method uses the current sampling value and the last filtering output value for weighting to obtain an effective filtering value, so that the output has a feedback effect on the input.

[0025] Preferably, the limited averaging includes calculating the average value of the 100 sampling points, and each sampling point is compared with the average value. If the difference between the current value and the average value exceeds a set threshold, it is discarded, and if it does not exceed, it is retained. Finally, the average value of the acceleration value after limited averaging is calculated, and the threshold is set to 3°.

[0026] Preferably, the X-axis and Y-axis of the acceleration sensor correspond to the X-axis and Y-axis of the pressure plate respectively, the direction of the Y-axis points to the center of the earth, and the Z-axis of the acceleration sensor is perpendicular to the plane of the pressure plate.

[0027] Preferably, the acceleration sensor is adsorbed on the pressure plate plane by a magnet.

[0028] Preferably, the acceleration sensor and the pressure plate are both provided with connection holes, and fixing screws are arranged in two corresponding connection holes.

[0029] Preferably, the acceleration sensor and the pressure plate rotate synchronously, and the acceleration of the acceleration sensor on the Z axis remains unchanged.

[0030] Preferably, after the acceleration of the acceleration sensor on the X-axis and the Y-axis is stabilized, the direction of the resultant force is gravity, and the acceleration is the acceleration due to gravity.

[0031] Preferably, a plurality of acceleration sensors are provided, and the plurality of acceleration sensors are respectively installed on corresponding pressure plates, and the plurality of acceleration sensors are all connected to computer signals, and the plurality of acceleration sensors are numbered respectively, and the output data of each numbered acceleration sensor is compared by a computer, and the comparison is used to monitor whether any output data of a single acceleration sensor produces an abnormality.

[0032] The technical effects and advantages provided by the present invention are:

[0033] 1. When the pressure plate rotates or tilts at an angle, the acceleration sensor and the pressure plate rotate and tilt synchronously, and the acceleration of the Z-axis of the acceleration sensor remains unchanged. After the acceleration of the X-axis and Y-axis of the acceleration sensor stabilizes, the direction of the resultant force is gravity. At this time, the acceleration of the acceleration sensor is the acceleration of gravity. The acceleration sensor can be used to monitor the inclination data of the pressure plate, and the three-axis inclination is calculated by the digital filtering method. The three-axis inclination value is optimized to reduce the burrs of the acceleration value and make the data more accurate.

[0034] 2. By setting up multiple acceleration sensors, multiple acceleration sensors are installed on corresponding pressure plates respectively, and multiple different pressure plates are monitored at the same time, multiple monitored acceleration values ​​are optimized by digital filtering, burrs are removed, and more accurate data is obtained, making the monitoring of the pressure plate after it is put into use safer and more stable, reducing the time of manual monitoring by personnel, improving efficiency, and the cost of use is low.

[0035] 3. Multiple acceleration sensors are connected to computer signals, and the multiple acceleration sensors are numbered respectively. The output data of each numbered acceleration sensor is compared by the computer. By comparing and monitoring whether there is any abnormality in the output data of a single acceleration sensor, the personnel can be reminded to quickly detect or repair the numbered acceleration sensor. The location of the acceleration sensor with wrong data can be quickly found by numbering. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the step structure of the angle detection method of the present invention.

[0037] Figure 2 It is a schematic diagram of the X-axis and Y-axis indicating direction structure of the pressure lifting plate of the present invention.

[0038] Figure 3 The present invention provides a schematic diagram of the connection structure between the acceleration sensor and the computer. DETAILED DESCRIPTION

[0039] The present invention provides Figure 1 to Figure 3 The application of an angle detection method shown includes the following steps:

[0040] The first step is to install the acceleration sensor on the pressure plate in the substation protection tripping circuit, wherein the pressure plate is a device used to control the connection or exit of the relay protection device, usually installed on the secondary control circuit, and the relay protection device can be opened or closed by throwing and withdrawing the pressure plate, thereby realizing the protection function of the power system. It is generally used in the substation protection tripping circuit. According to the different positions of the pressure plate connected to the secondary circuit of the protection device, it can be divided into two categories: protection function pressure plate and outlet pressure plate. In the present invention, the acceleration sensor is installed on the protection function pressure plate for use.

[0041] The acceleration sensor uses a micro-electromechanical system acceleration sensor. Different from the traditional acceleration sensor, the micro-electromechanical system acceleration sensor is a micro system that integrates micro-sensors, micro-actuators, signal processing circuits and communication interfaces. It is widely used in various fields due to its low cost, low power consumption, high reliability, easy integration and intelligence. However, when the acceleration sensor is used on the platen to measure the inclination of the platen, the original acceleration value output by the micro-electromechanical system acceleration sensor is unstable and has many burrs due to the influence of factors such as the process level and the core sensor. If the original data is directly used, the inclination value obtained will fluctuate greatly and have a high error.

[0042] In actual operation and installation, the X-axis and Y-axis of the acceleration sensor correspond to the X-axis and Y-axis of the pressure plate respectively, the direction of the Y-axis points to the center of the earth, the Z-axis of the acceleration sensor is perpendicular to the plane of the pressure plate, and the X-axis and Y-axis are distributed at a vertical angle.

[0043] When the pressure plate rotates or tilts at an angle, the acceleration sensor and the pressure plate rotate and tilt synchronously, and the acceleration of the acceleration sensor Z axis remains unchanged. After the acceleration of the acceleration sensor X axis and Y axis stabilizes, the direction of the resultant force is gravity. At this time, the acceleration of the acceleration sensor is the acceleration of gravity.

[0044] Therefore, the second step is to calculate the three-axis inclination angle through the digital filtering method, optimize the three-axis inclination angle value, reduce the burr of the acceleration value, and make the data more accurate.

[0045] The digital filtering method collects raw acceleration data at a sampling frequency of 100 Hz and uses 1 Hz as the output frequency;

[0046] Specifically, the digital filtering method includes:

[0047] Collect the original three-axis acceleration values, and perform first-order low-pass filtering on the x-axis, y-axis, and z-axis acceleration values. Specifically, the first-order low-pass filtering algorithm formula is as follows:

[0048] Y(n)=αX(n)+(1-α)Y(n-1)

[0049] Among them, α is the filter coefficient, X(n) is the current sample sampling value, Y(n-1) is the previous filter output value, and Y(n) is the current filter output value.

[0050] The first-order low-pass filtering method uses the current sampling value and the last filtering output value to weight and obtain the effective filtering value, so that the output has a feedback effect on the input.

[0051] For every 100 sampling points of the filtered three-axis acceleration values, perform a limited average.

[0052] Step 3: Substitute the three-axis acceleration values ​​after limiting and averaging into the calculation formula to calculate the x-axis angle and the y-axis angle, and obtain the x-axis inclination angle and the y-axis inclination angle respectively;

[0053] The calculation formula is as follows:

[0054]

[0055]

[0056]

[0057] Since the acceleration sensor mainly measures the value of gravity acceleration, when an offset occurs, gravity acceleration will generate components on the x-axis and y-axis. In the case of relative stillness, the angle value of the x-axis and y-axis can be obtained and output through the trigonometric function relationship. Therefore, the relationship between the offset angle of the x-axis and y-axis relative to the horizontal plane and the acceleration is shown in the above formula.

[0058] Among them, angle x Indicates the offset angle between the x-axis and the horizontal plane, angle y Indicates the offset angle between the y-axis and the horizontal plane, angle z Indicates the offset angle between the z-axis and the horizontal plane, a x represents the component of acceleration on the x-axis, a y represents the component of acceleration on the y-axis, a z represents the component of acceleration on the z-axis, tanh represents the inverse tangent function, and pi represents pi;

[0059] Step 4: Calibrate the obtained x-axis inclination angle and y-axis inclination angle, take the previous x average angle data of the acceleration sensor as the initial reference value, and the calibration angle is equal to the current angle.

[0060] The limited averaging includes calculating the average value of the 100 sampling points, and then comparing each sampling point with the average value. If the difference between the current value and the average value exceeds the set threshold, it is discarded, and if it does not exceed, it is retained. Finally, the average value of the acceleration value after limited averaging is calculated, and the threshold is set to 3°.

[0061] There are various ways to install the acceleration sensor and the pressure plate. The acceleration sensor can be adsorbed on the pressure plate plane through a magnet. Magnets are fixed on opposite sides of the acceleration sensor and the pressure plate, and the two magnets are adsorbed and connected to each other.

[0062] The acceleration sensor and the pressure plate may also be provided with connection holes, and fixing screws may be provided in two corresponding connection holes, so that the connection is more stable through the fixing screws.

[0063] Moreover, the correctness of the pressure plate position directly affects the correctness of the operation of automatic devices such as relays, thereby affecting the safe and stable operation of the power system.

[0064] There are two main methods for monitoring the pressure plate in traditional technology: one is visual information recognition, including drone inspections, etc. In actual use, it has high requirements for the optical environment and requires the installation of cameras and carts. The second is the method of leading out the switch quantity, and obtaining the pressure plate status by monitoring the switch quantity. This method leads the wiring from each switch quantity, requires a large number of wiring cables, increases the complexity of the secondary circuit, and is difficult to monitor the pressure plates in multiple different positions.

[0065] Therefore, a plurality of acceleration sensors are provided, and the plurality of acceleration sensors are respectively installed on pressure plates at different positions, and the plurality of acceleration sensors are all connected to computer signals. The plurality of acceleration sensors are numbered respectively, and the output data of each numbered acceleration sensor is compared through a computer, and the comparison is used to monitor whether any output data of a single acceleration sensor is abnormal.

[0066] When the acceleration sensors at different positions monitor the data of the corresponding pressure plates and send them to the computer, when the computer monitors that the acceleration data of a certain pressure plate is significantly different from other data, the data with the larger data difference will be processed first. Since the deflection angle of the pressure plate in the substation protection tripping circuit has a maximum value, if the data sent by the acceleration sensor exceeds the maximum value, it means that the acceleration sensor is damaged, or that the connection between the acceleration sensor and the pressure plate is detached, and the three axes of the acceleration sensor no longer correspond to the pressure plate.

[0067] The personnel can be reminded to quickly inspect or repair the acceleration sensor with the number. The location of the acceleration sensor with wrong data can be quickly found by the number.

[0068] By setting up multiple acceleration sensors, multiple different pressure plates are monitored at the same time, and digital filtering is used to optimize the multiple monitored acceleration values ​​to remove burrs and obtain more accurate data, making the monitoring of the pressure plate after it is put into use safer and more stable, reducing the time for manual monitoring by personnel, improving efficiency, and having a lower cost of use.

[0069] It can solve the problems in traditional methods, such as the high requirements for the installation environment of drone patrol methods and the need for a large number of wiring cables for monitoring switch quantities, which increases the complexity.

[0070] Specifically, in practical applications, accelerometers usually need to be calibrated. Calibration can improve the accuracy and stability of the sensor. The calibration process includes determining the zero offset and sensitivity of the accelerometer. Zero offset refers to the value of the sensor output without acceleration, which needs to be adjusted to zero. Sensitivity refers to the change in the output of the accelerometer caused by a unit acceleration change, which can be determined through calibration and calibration.

[0071] When using an accelerometer, you also need to pay attention to the installation position and direction of the sensor. The accelerometer should be installed perpendicular to the acceleration direction of the platen as much as possible to obtain the most accurate measurement results. In addition, the accelerometer also needs to avoid external interference, such as vibration, temperature changes, etc., which may affect the measurement results of the accelerometer.

[0072] Since the temperature in the substation is relatively constant and the probability of vibration is low, there is no need for additional protection devices to protect the acceleration sensor.

[0073] When collecting and processing data, corresponding software or programming language can be used to read and analyze the data output by the acceleration sensor. By analyzing the data output by the acceleration sensor, the acceleration information of the pressure plate can be obtained, for example, by connecting the acceleration sensor to a computer for signal connection.

[0074] For example, if the acceleration sensor outputs an analog signal to the computer's AD board (or other sampling device), the AD board converts the analog quantity into a digital quantity as data that the computer can recognize. In addition, the acceleration sensor has a bus interface (such as RS-232, RS-485, CAN, etc.), and the computer directly reads the signal of the acceleration sensor through the corresponding bus. Since the connection method is a prior art, it will not be elaborated on.

Claims

1. An application of an angle detection method, characterized in that: The following steps are involved: S1. Installing an acceleration sensor on a pressure plate in a protection tripping circuit of a substation, wherein the acceleration sensor uses a micro-electromechanical system acceleration sensor; S2, calculate the three-axis inclination angle by digital filtering method, the digital filtering method collects the original acceleration data at a sampling frequency of 100 Hz and takes 1 Hz as the output frequency; Digital filtering methods include: Collect the original three-axis acceleration values, and perform first-order low-pass filtering on the x-axis, y-axis, and z-axis acceleration values ​​respectively; For every 100 sampling points of the filtered three-axis acceleration values, perform a limited average. S3, substituting the three-axis acceleration values ​​after limiting and averaging into the calculation formula, calculating the x-axis angle and the y-axis angle, and obtaining the x-axis inclination angle and the y-axis inclination angle respectively; The calculation formula is as follows: Among them, angle x Indicates the offset angle between the x-axis and the horizontal plane, angle y Indicates the offset angle between the y-axis and the horizontal plane, angle z Indicates the offset angle between the z-axis and the horizontal plane, a x represents the component of acceleration on the x-axis, a y represents the component of acceleration on the y-axis, a z represents the component of acceleration on the z-axis, tanh represents the inverse tangent function, and pi represents pi; S4. Calibrate the obtained x-axis inclination angle and y-axis inclination angle, take the first x average angle data of the acceleration sensor as the initial reference value, and the calibration angle is equal to the current angle.

2. The application of the angle detection method according to claim 1, characterized in that: The first-order low-pass filtering algorithm formula is as follows: Y(n)=αX(n)+(1-α)Y(n-1) Among them, α is the filter coefficient, X(n) is the current sample sampling value, Y(n-1) is the previous filter output value, and Y(n) is the current filter output value.

3. The application of the angle detection method according to claim 2, characterized in that: The first-order low-pass filtering method uses the current sample sampling value and the last filtering output value for weighting to obtain an effective filtering value.

4. The application of the angle detection method according to claim 1, characterized in that: The limited averaging includes calculating the average value of the 100 sampling points, and then comparing each sampling point with the average value. If the difference between the current value and the average value exceeds a set threshold, it is discarded, and if it does not exceed, it is retained. Finally, the average value of the acceleration value after limited averaging is calculated, and the threshold is set to 3°.

5. The application of the angle detection method according to claim 1, characterized in that: The X-axis and Y-axis of the acceleration sensor correspond to the X-axis and Y-axis of the pressure plate respectively, the direction of the Y-axis points to the center of the earth, and the Z-axis of the acceleration sensor is perpendicular to the plane of the pressure plate.

6. The application of the angle detection method according to claim 1, characterized in that: The acceleration sensor is adsorbed on the pressure plate plane through a magnet.

7. The application of the angle detection method according to claim 1, characterized in that: The acceleration sensor and the pressure plate are both provided with connection holes, and fixing screws are arranged in two corresponding connection holes.

8. The application of the angle detection method according to claim 1, characterized in that: The acceleration sensor and the pressure plate rotate synchronously, and the acceleration of the acceleration sensor on the Z axis remains unchanged.

9. The application of the angle detection method according to claim 1, characterized in that: After the acceleration of the X-axis and Y-axis of the acceleration sensor stabilizes, the direction of the resultant force is gravity, and the acceleration is the acceleration of gravity.

10. The application of the angle detection method according to claim 1, characterized in that: The acceleration sensors are provided in plurality, and the plurality of acceleration sensors are respectively installed on different pressure plates, and the plurality of acceleration sensors are all connected to computer signals, and the plurality of acceleration sensors are numbered respectively, and the output data of each numbered acceleration sensor is compared by a computer, and the comparison is used to monitor whether the output data of a single acceleration sensor is abnormal.

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