Transient calibration method and system for electric field sensor of transformer substation

Abstract

The invention discloses a transformer substation electric field sensor transient calibration method and system, and relates to the technical field of electric field sensors, and the method comprises the steps: obtaining the transient calibration parameters and structure size of a transformer substation electric field sensor, and analyzing the effective use space of an anechoic chamber, and obtaining the size of a test space; performing calculation based on the transient calibration parameters, the structure size and the test space size to obtain a theoretical value range of a direct-current high-voltage value; processing alternating current mains supply based on the theoretical value range to obtain a high-voltage direct current power supply; the working data of the high-voltage direct-current power supply is adjusted, a trigger signal is generated, and a sharpening circuit is controlled to generate a high-voltage pulse signal; and transmitting the high-voltage pulse signal to a test transmission line, generating an electric field in the test space, and carrying out instant calibration on the electric field sensor. The electric field generated by the invention can simultaneously meet the requirement of the nanosecond rising edge of the electric field sensor and the transient calibration requirement of several kV transient ground potential rise and several kV / m transient electric field.

Description

Technical Field

[0001] The invention relates to the technical field of electric field sensors, and in particular to a method and system for transient calibration of electric field sensors in a transformer substation. Background Art

[0002] As an important device for monitoring electric field strength in substations, the measurement accuracy of electric field sensors is directly related to the safe operation and equipment protection of substations. During the operation of the power system, electric field sensors need to accurately sense and measure various complex electric field changes to provide key data support for system safety assessment and equipment status monitoring. At present, electric field sensors must undergo a strict calibration process before being put into use, including transient calibration and steady-state calibration. Transient calibration is mainly used to determine the time domain characteristics of the sensor, especially the measurement of rise time, which needs to meet the nanosecond rise edge requirements. Steady-state calibration is mainly used to determine the frequency domain characteristics of the sensor and realize -3dB bandwidth calibration. The accurate implementation of these two calibration methods is of great significance to ensure the measurement reliability of electric field sensors.

[0003] However, the existing calibration methods have many shortcomings: first, traditional calibration methods often find it difficult to simultaneously meet the dual requirements of nanosecond rising edges and several kV transient ground potential increases, which seriously restricts the accuracy of the calibration results; second, when the existing calibration system generates a high-intensity transient electric field, it is often affected by external electromagnetic interference, resulting in deviations in the test results; third, when dealing with transient electric fields of the order of several kV / m, the current calibration methods generally have problems with signal distortion and insufficient measurement accuracy; in addition, when generating high-voltage pulse signals, the existing technology often adopts a simple step-up conversion method, which makes it difficult to ensure the stability and controllability of the output signal, which directly affects the reliability of the calibration process; finally, the traditional calibration system lacks effective control over the test environment, especially in terms of optimizing the use space of the anechoic chamber, which makes the calibration results easily affected by environmental factors. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the problem to be solved by the present invention is how to provide a transient calibration method for substation electric field sensors, which can adjust the transient calibration electric field according to the actual needs of the substation, and the generated electric field can simultaneously meet the requirements of the nanosecond rising edge of the electric field sensor and the transient calibration requirements of the transient ground potential rise of several kV and the transient electric field of several kV / m.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In the first aspect, an embodiment of the present invention provides a transient calibration method for a substation electric field sensor, which includes obtaining transient calibration parameters and structural dimensions of the substation electric field sensor, and analyzing the effective use space of the radio wave darkroom to obtain the test space dimensions; calculating based on the transient calibration parameters, structural dimensions and test space dimensions to obtain a theoretical value range of DC high voltage values; processing the AC mains based on the theoretical value range to obtain a high-voltage DC power supply; adjusting the working data of the high-voltage DC power supply to generate a trigger signal and control the sharpening circuit to generate a high-voltage pulse signal; transmitting the high-voltage pulse signal to the test transmission line, generating an electric field in the test space and instantaneously calibrating the electric field sensor.

[0008] As a preferred scheme of the transient calibration method of the substation electric field sensor described in the present invention, the high-voltage DC power supply includes the following steps: rectifying and filtering the single-phase A1V and B1Hz AC mains to obtain a DC voltage of A2V; performing IGBT module frequency conversion on the DC voltage of A2V to obtain a B2kHz pulsating AC; performing a high-frequency transformer to boost the B2kHz pulsating AC to obtain an A3kV pulsating high voltage; dividing the A3kV pulsating high voltage into two groups of N voltage multipliers for the first boost, and rectifying to form a DC high voltage with adjustable positive and negative voltages in the range of A4 to A5kV.

[0009] As a preferred scheme of the transient calibration method of the substation electric field sensor described in the present invention, adjusting the working data of the high-voltage DC power supply refers to charging two groups of energy storage capacitors and sharpening capacitors respectively, discharging through a magnetically controlled mechanical stepping SF6 insulating gas switch, and then doubling the voltage to output a transient pulse high voltage adjustable from A6 to A7kV.

[0010] As a preferred solution of the instantaneous calibration method of the substation electric field sensor of the present invention, the equivalent model of the sharpening circuit includes the energy storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , main switch K and load resistor R; the energy storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , the main switch K and the load resistor R are connected in sequence to form a closed loop; the sharpening capacitor C tr One end is connected to the energy storage capacitor and inductor L M With sharpening inductance L tr The other end is connected to the energy storage capacitor C M Keep away from energy storage capacitor and inductor L M end of.

[0011] As a preferred solution of the instantaneous calibration method of the substation electric field sensor of the present invention, the generating of the trigger signal and controlling the sharpening circuit to generate the high-voltage pulse signal comprises the following steps: using a DC high-voltage source to supply the energy storage capacitor C M Charge to U0, and discharge to the load resistor R through the main switch K under the trigger condition; when the main switch K is turned on at t=0, the calculation formula of the circuit equation is as follows:

[0012]

[0013] Where, L is the total distributed inductance of the circuit; R is the load resistance; C tr is a sharpening capacitor with energy storage function; t is time; i is the current in the circuit; let the energy storage capacitor C M The voltage drop across is u c (t), using the initial condition I0 = 0, u c (0) = U0 to calculate the critical ratio. The calculation formula of the critical ratio is as follows:

[0014]

[0015] Wherein, α is the critical ratio, when α < 1, it is underdamped, when α = 1, it is critically damped, when α > 1, it is overdamped; R is the load resistance; C M is the energy storage capacitor; L is the total distributed inductance of the circuit; when the critical ratio α>>1, the specific formula of the current flowing through the load resistor R is as follows:

[0016]

[0017] Where I0(t) is the current flowing through the load resistor R; U R is the voltage of the load resistor R; R is the load resistor; Rc is the time constant of the charging circuit; L is the total distributed inductance of the circuit; U0 is the initial voltage; τ2 is the resistance-capacitance time constant; τ1 is the inductance-resistance time constant; the specific formula after the voltage of the load resistor R is reduced is as follows:

[0018]

[0019] Among them, U0(t) is the voltage after the voltage of the load resistor R is reduced; the specific formula of the rise time is as follows:

[0020]

[0021] Among them, t r is the rise time; t1 is the characteristic time parameter; the specific formula for the decay time is as follows:

[0022] tf ≈2.2t2=2.2RC M

[0023] Among them, t f is the fading time; t2 is the characteristic time parameter; the specific formula of the half-height width is as follows:

[0024] τ 0.5 ≈0.7C M R

[0025] Among them, τ 0.5 is the half-height width.

[0026] As a preferred scheme of the transient calibration method of the substation electric field sensor described in the present invention, the generating of the electric field in the test space and the instantaneous calibration of the electric field sensor include the following steps: installing different types of sensors in the test space, measuring the electric field, magnetic field, electric field, magnetic field and waveform generated by the simulator, transmitting various analog data outside the anechoic chamber, and displaying, reading and storing the data through an oscilloscope; using a distributed terminal matching load resistor when instantaneously calibrating the electric field sensor.

[0027] As a preferred solution of the transient calibration method of the substation electric field sensor of the present invention, wherein: the transient calibration parameters of the electric field sensor include peak field strength, rising edge and oscilloscope; the effective use space of the anechoic chamber is 1 / T of the actual height of the anechoic chamber.

[0028] In the second aspect, in order to further solve the safety problems existing in electric field sensors, the present invention provides a transient calibration system for substation electric field sensors in an embodiment, which includes: a data acquisition module, used to obtain transient calibration parameters and structural dimensions of electric field sensors, and analyze the effective use space of the radio wave darkroom to obtain the test space dimensions; a theoretical value module, used to calculate according to the transient calibration parameters, structural dimensions and test space dimensions to obtain the theoretical value range of DC high voltage values; an AC mains module, used to process the AC mains according to the theoretical value range of DC high voltage values ​​to obtain a high-voltage DC power supply that meets the theoretical value range of DC high voltage values; a high-voltage pulse module, used to adjust the working data of the high-voltage DC power supply, and control the sharpening circuit to generate a high-voltage pulse signal; a transient calibration module, used to transmit the high-voltage pulse signal to the test transmission line, generate an electric field that meets the test requirements in the test space, and instantaneously calibrate the electric field sensor in the test space.

[0029] In a third aspect, an embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program is executed by the processor, any step of a transient calibration method for a substation electric field sensor as described in the first aspect of the present invention is implemented.

[0030] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, it implements any step of a transient calibration method for a substation electric field sensor as described in the first aspect of the present invention.

[0031] Beneficial effects of the invention: The invention provides a transient calibration method for substation electric field sensors, which can adjust the transient calibration electric field according to the actual needs of the substation, and the generated electric field can simultaneously meet the requirements of the nanosecond rising edge of the electric field sensor and the transient calibration requirements of the transient ground potential rise of several kV and the transient electric field of several kV / m. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0033] Figure 1 This is an overall flow chart of a transient calibration method for a substation electric field sensor in Example 1.

[0034] Figure 2 This is a schematic diagram of the transient calibration method for the substation electric field sensor in Example 1.

[0035] Figure 3 This is the overall design block diagram of the high voltage pulse source in Example 1.

[0036] Figure 4 Schematic diagram of the equivalent circuit of the high-voltage pulse source sharpening structure in Example 1.

[0037] Figure 5 This is a schematic diagram of the structure of the computer device in Example 3.

[0038] Figure 6 Schematic diagram of the relationship between the width and height of the upper electrode plate and the transmission line impedance in Example 4.

[0039] Figure 7 Schematic diagram of the relationship between the width of the upper and lower plates and the transmission line impedance in Example 4.

[0040] Figure 8 This is the electric field transient calibration waveform diagram in Example 4. DETAILED DESCRIPTION

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0042] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0044] Example 1

[0045] Reference Figure 1 to Figure 4 , which is the first embodiment of the present invention, and provides a transient calibration method for a substation electric field sensor.

[0046] The existing electric field sensor calibration methods mainly have the following problems: First, traditional calibration methods often find it difficult to simultaneously meet the dual requirements of nanosecond rising edges and several kV transient ground potential increases, which seriously restricts the accuracy of the calibration results; second, when the existing calibration system generates a high-intensity transient electric field, it is often affected by external electromagnetic interference, resulting in deviations in the test results; third, when the current calibration method deals with transient electric fields of the order of several kV / m, there are generally problems of signal distortion and insufficient measurement accuracy; in addition, when generating high-voltage pulse signals, the existing technology often adopts a simple step-up conversion method, which makes it difficult to ensure the stability and controllability of the output signal, which directly affects the reliability of the calibration process; finally, the traditional calibration system lacks effective control over the test environment, especially in terms of optimizing the use space of the anechoic chamber, which makes the calibration results easily affected by environmental factors.

[0047] The present application provides an effective solution to the above-mentioned problems. Next, multiple embodiments will be combined to explain in detail how to implement the transient calibration method of the substation electric field sensor.

[0048] Figure 1 The overall flow chart of a method for transient calibration of electric field sensors in a substation is shown, including:

[0049] S1: Obtain the transient calibration parameters and structural dimensions of the substation electric field sensor, analyze the effective use space of the anechoic chamber, and obtain the test space dimensions.

[0050] Preferably, the transient calibration parameters of the electric field sensor include peak field strength, rising edge and oscilloscope, wherein transient calibration refers to satisfying the requirement of reaching a voltage of several kV within a few ns.

[0051] Specifically, the peak field strength required for the transient calibration of the electric field sensor is 5 kV / m.

[0052] Specifically, the rising edge refers to the time it takes for a signal to change from a low level to a high level, and is used to describe the response speed of a sensor.

[0053] Preferably, the effectively usable space of the anechoic chamber is 1 / 3 of the actual height of the anechoic chamber.

[0054] Further, such as Figure 2 The figure shows the schematic diagram of the transient calibration method of the substation electric field sensor, in which the control circuit A is used to adjust the working data of the high-voltage DC power supply, and generate a trigger signal to control the sharpening circuit to generate a high-voltage pulse signal, and transmit the output high-voltage pulse signal to the test transmission line to generate an electric field that meets the test requirements within a certain space; the distributed terminal is used to match the load resistance and absorb the pulse to avoid reflection; the data exchange between the control system and the high-voltage pulse generator, that is, the high-voltage DC power supply and the sharpening circuit adopts optical cable isolation.

[0055] Preferably, the present invention defines the relationship between the effective usable space limit of the anechoic chamber and the actual height by utilizing a specific ratio. Since the electric field strength will change gradiently with increasing height in the anechoic chamber, and the rate of change of the electric field strength at a specific height is the smallest, it is most suitable for accurate measurement, thereby making the electric field distribution in the space most uniform, and can effectively reduce measurement errors.

[0056] S2: Calculate based on transient calibration parameters, structural dimensions and test space dimensions to obtain the theoretical range of DC high voltage values.

[0057] S3: Process the AC mains power based on the theoretical value range to obtain a high voltage DC power supply.

[0058] Preferably, the processing of the AC mains power includes rectification and filtering, frequency conversion, voltage boosting and rectification processing.

[0059] Specifically, Figure 3 The figure shows the overall design block diagram of the high-voltage pulse source. The high-voltage DC power supply includes the following steps: rectifying and filtering the single-phase 220V, 50Hz AC mains to obtain a 310V DC voltage.

[0060] The 310V DC voltage is frequency-converted by the IGBT module to obtain a 30kHz pulsating AC.

[0061] The 30kHz pulsating AC is boosted by a high-frequency transformer to obtain a 20kV pulsating high voltage.

[0062] The 20kV pulsating high voltage is divided into two groups of 8-fold voltage boosters for the first time, and rectified to form a DC high voltage with positive and negative voltages adjustable in the range of 0.4 to 150kV.

[0063] Preferably, the present invention adopts a multi-stage boosting scheme of "rectification filtering-frequency conversion-boosting-rectification", especially converting the voltage into 30kHz high-frequency AC through the IGBT module. The selection of this frequency not only ensures the boosting efficiency of the transformer, but also avoids the core loss caused by excessive frequency. Subsequently, two groups of 8-fold voltage multipliers are used for boosting to form an adjustable DC high voltage in the range of 0.4 to 150kV. Compared with the traditional single-stage boosting, the present invention has better voltage regulation accuracy and stability.

[0064] S4: Adjust the working data of the high-voltage DC power supply, generate a trigger signal and control the sharpening circuit to generate a high-voltage pulse signal.

[0065] Preferably, adjusting the working data of the high-voltage DC power supply means charging two groups of energy storage capacitors and sharpening capacitors respectively, discharging through a magnetically controlled mechanical stepping SF6 insulating gas switch, and then doubling the voltage twice to output an adjustable transient pulse high voltage of 0.8 to 300 kV.

[0066] It should be noted that the pulse power switch, high voltage regulation, linear DC regulated power supply voltage feedback, high voltage feedback, current feedback circuit and protection circuit used in the present invention are all controlled by a computer through optical fiber.

[0067] Preferably, the equivalent model of the sharpening circuit includes a storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , main switch K and load resistor R.

[0068] Specifically, the energy storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , main switch K and load resistor R are connected in sequence to form a closed loop.

[0069] Sharpening capacitor C tr One end is connected to the energy storage capacitor and inductor L M With sharpening inductance L trThe other end is connected to the energy storage capacitor C M Keep away from energy storage capacitor and inductor L M end of.

[0070] Further, such as Figure 4 The figure shows the equivalent circuit diagram of the high-voltage pulse source sharpening structure. The steps of generating a trigger signal and controlling the sharpening circuit to generate a high-voltage pulse signal include: using a DC high-voltage source to supply power to the energy storage capacitor C M It is charged to U0 and discharged to the load resistor R through the main switch K under the trigger condition, wherein the circuit is a standard RLC series discharge circuit.

[0071] When the main switch K is turned on at t=0, the calculation formula of the circuit equation is as follows:

[0072]

[0073] Where, L is the total distributed inductance of the circuit; R is the load resistance; C tr is a sharpening capacitor that also has energy storage function; t is time; i is the current in the circuit.

[0074] Assume that the energy storage capacitor C M The voltage drop across is u c (t), using the initial condition I0 = 0, u c (0) = U0 to calculate the critical ratio. The calculation formula of the critical ratio is as follows:

[0075]

[0076] Wherein, α is the critical ratio, when α < 1, it is underdamped, when α = 1, it is critically damped, when α > 1, it is overdamped; R is the load resistance; C M is the energy storage capacitor; L is the total distributed inductance of the circuit.

[0077] When the critical ratio α>>1, the specific formula for the current flowing through the load resistor R is as follows:

[0078]

[0079] Where I0(t) is the current flowing through the load resistor R; U R is the voltage of the load resistor R; R is the load resistor; Rc is the time constant of the charging circuit; L is the total distributed inductance of the circuit; U0 is the initial voltage; τ2 is the resistance-capacitance time constant, that is, the load resistor R and the energy storage capacitor C M The product of ; τ1 is the inductance-resistance time constant, that is, the ratio of the total distributed inductance L of the circuit to the load resistance R.

[0080] The specific formula after the voltage of the load resistor R is reduced is as follows:

[0081]

[0082] Among them, U0(t) is the voltage after the voltage of the load resistor R is reduced, and the corresponding waveform is a double exponential pulse waveform.

[0083] The specific formula for rise time is as follows:

[0084]

[0085] Among them, t r is the rise time; t1 is the characteristic time parameter, that is, the ratio of the total distributed inductance L of the circuit to the load resistance R.

[0086] The specific formula for the fading time is as follows:

[0087] t f ≈2.2t2=2.2RC M

[0088] Among them, t f is the decay time; t2 is the characteristic time parameter, namely the load resistance R and the energy storage capacitor C M The product of .

[0089] The specific formula for half-height width is as follows:

[0090] τ 0.5 ≈0.7C M R

[0091] Among them, τ 0.5 is the half-height width.

[0092] Preferably, the sharpening circuit proposed in the present invention adopts a special structure of energy storage capacitors and sharpening capacitors connected in series and parallel, and realizes an adjustable transient pulse high-voltage output of 0.8 to 300 kV through the discharge of a magnetically controlled mechanical stepping SF6 insulating gas switch, wherein the excellent insulation performance of SF6 gas is utilized to improve the stability of the system; accurate voltage regulation is achieved through stepping switch control; the coordinated work of the energy storage capacitor and the sharpening capacitor enables the rise time of the output pulse to reach the ns level; in addition, optical fiber is used for control signal transmission under high-voltage environment to effectively isolate strong electric field interference, improve the anti-interference ability of the system, and ensure the stability and reliability of the control system.

[0093] S5: Transmit the high voltage pulse signal to the test transmission line, generate an electric field in the test space and instantaneously calibrate the electric field sensor.

[0094] Preferably, generating an electric field in the test space and instantaneously calibrating the electric field sensor comprises the following steps: installing different types of sensors in the test space to measure the electric field, magnetic field generated by the simulator, the electric field, magnetic field and waveform inside the test body.

[0095] The analog data are transmitted outside the anechoic chamber and displayed, read and stored through an oscilloscope.

[0096] Furthermore, when instantaneously calibrating the electric field sensor, a distributed terminal matching load resistor is used to absorb pulses and avoid reflections.

[0097] Preferably, the present invention adopts a distributed terminal matching load resistance to absorb pulses and avoid reflections. By accurately matching impedance, the influence of reflected waves is minimized, the measurement accuracy is improved, and the reliability of the calibration results is ensured.

[0098] In summary, the present invention provides a transient calibration method for substation electric field sensors, which can adjust the transient calibration electric field according to the actual needs of the substation, and the generated electric field can simultaneously meet the nanosecond rising edge requirements of the electric field sensor and the transient calibration requirements of transient ground potential rises of several kV and transient electric fields of several kV / m.

[0099] Embodiment 2 is an embodiment of the present invention, which provides a transient calibration system for electric field sensors in a substation, including: a data acquisition module, used to obtain transient calibration parameters and structural dimensions of electric field sensors, and analyze the effective use space of the radio wave darkroom to obtain the test space dimensions; a theoretical value module, used to calculate according to the transient calibration parameters, structural dimensions and test space dimensions to obtain the theoretical value range of DC high voltage values; an AC mains module, used to process the AC mains according to the theoretical value range of DC high voltage values ​​to obtain a high-voltage DC power supply that meets the theoretical value range of DC high voltage values; a high-voltage pulse module, used to adjust the working data of the high-voltage DC power supply and control the sharpening circuit to generate a high-voltage pulse signal; a transient calibration module, used to transmit the high-voltage pulse signal to the test transmission line, generate an electric field that meets the test requirements in the test space, and instantaneously calibrate the electric field sensor in the test space.

[0100] Embodiment 3 is an embodiment of the present invention, which is different from the previous embodiment in that:

[0101] like Figure 5As shown, if the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0102] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0103] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0104] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0105] Example 4 is an embodiment of the present invention, which provides a transient calibration method for a substation electric field sensor. In order to verify the beneficial effects of the present invention, a scientific demonstration is carried out through simulation experiments.

[0106] This example takes a substation as an example, analyzes the historical operation data of the substation, and obtains the transient calibration parameters of the corresponding electric field sensor, where the peak field strength is 5kV / m, the rising edge is ≤3.5ns (100MHz), and the parameters of the oscilloscope are analog bandwidth ≥500MHz, sampling rate ≥2GSa / s; first, in the experiment, the control circuit A is used to adjust the working data of the high-voltage DC power supply, and generate a trigger signal to control the sharpening circuit to generate a high-voltage pulse signal, and transmit the output high-voltage pulse signal to the test transmission line to generate an electric field that meets the test requirements in a certain space; the distributed terminal matching load resistor absorbs the pulse to avoid reflection; the data exchange between the control system and the high-voltage pulse generator (high-voltage DC power supply + sharpening circuit) adopts optical cable isolation; different types of sensors are installed in the test space to measure the electric field and magnetic field generated by the simulator and the electric field, magnetic field and other data and waveforms inside the test body; various analog quantity data are transmitted to the outside of the radio wave darkroom, and the data is displayed, read and stored by the oscilloscope.

[0107] Secondly, the test system used in this example can be installed indoors or outdoors. When placed outdoors, in order to prevent strong electric field pulses from interfering with the control and measurement equipment, the control and measurement equipment must be placed in a shielding facility; since the electric field of 5kV / m needs to be met, and the effective use space of this set of metering equipment is 1 / 3 of the height H, it is necessary to first determine the height of the GIS electronic transformer, and then determine the DC high voltage value of the high-voltage power supply, and design the high-voltage power supply to be adjustable within a certain range to meet different voltage requirements.

[0108] In this example, since the choice of transmission line impedance will affect the signal strength received by the electric field sensor, the width of the upper and lower plates is closely related to the transmission line impedance, but it may reduce the sensitivity of the sensor. Figure 6 and Figure 7Shown are schematic diagrams of the relationship between the width and height of the upper plate and the transmission line impedance, and a schematic diagram of the relationship between the width of the upper and lower plates and the transmission line impedance. It can be seen from the figure that the aspect ratio of the upper plate is a / h, the width ratio of the upper and lower plates is w / a, W / a=2, and the read impedance is 97Ω, that is, (97 / 89)×115=125Ω, so the theoretical impedance R=115Ω, and the actual impedance R=125Ω.

[0109] In the design of electric field sensors, the rising edge refers to the time it takes for a signal to go from a low level to a high level, and is used to describe the response speed of the sensor. The rising edge range of the transient calibration of the entire system designed by the present invention is selected from a low level of 10% to a high level of 80%, such as Figure 8 The figure shows the electric field transient calibration waveform. The rising edge of the designed electric field sensor reaches 2.2514ns, which meets the requirement of rising edge ≤3.5ns (100MHz).

[0110] Based on the above content, it can be found that the transient calibration method proposed in the present invention calibrates the -3dB bandwidth and rising edge parameters of the measurement system. The -3dB bandwidth of the electric field sensor meets the requirement of 20kHz~500kHz, and thus meets the requirement of 100MHz electric field simulation bandwidth. The rising edge of the transient calibration meets the requirement of rising edge ≤3.5ns (100MHz).

[0111] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for transient calibration of electric field sensors in a substation, characterized in that: include: Obtain the transient calibration parameters and structural dimensions of the substation electric field sensor, analyze the effective use space of the anechoic chamber, and obtain the test space dimensions; Calculation is performed based on the transient calibration parameters, structural dimensions and test space dimensions to obtain a theoretical value range of the DC high voltage value; Processing the AC mains power based on the theoretical value range to obtain a high-voltage DC power supply; Adjusting the working data of the high-voltage DC power supply, generating a trigger signal and controlling the sharpening circuit to generate a high-voltage pulse signal; The high-voltage pulse signal is transmitted to the test transmission line, an electric field is generated in the test space, and the electric field sensor is instantaneously calibrated.

2. The method for transient calibration of electric field sensors in a substation according to claim 1, characterized in that: The obtaining of the high voltage DC power supply comprises the following steps: The single-phase A1V, B1Hz AC mains is rectified and filtered to obtain a DC voltage of A2V; The DC voltage of A2V is frequency-converted by an IGBT module to obtain a B2kHz pulsating AC; The B2kHz pulsating AC is boosted by a high-frequency transformer to obtain A3kV pulsating high voltage; The A3kV pulsating high voltage is divided into two groups of N voltage multipliers for the first step-up, and rectified to form a DC high voltage with positive and negative voltages adjustable within the range of A4-A5kV.

3. The method for transient calibration of electric field sensors in a substation according to claim 2, characterized in that: Adjusting the working data of the high-voltage DC power supply refers to charging two groups of energy storage capacitors and sharpening capacitors respectively, discharging through a magnetically controlled mechanical stepping SF6 insulating gas switch, and then doubling the voltage to output an adjustable transient pulse high voltage of A6~A7kV.

4. The method for transient calibration of electric field sensors in a substation according to claim 3, characterized in that: The equivalent model of the sharpening circuit includes the energy storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , main switch K and load resistor R; The energy storage capacitor C M , energy storage capacitor inductor L M , sharpening capacitor C tr , sharpening inductance L tr , the main switch K and the load resistor R are connected in sequence to form a closed loop; The sharpening capacitor C tr One end is connected to the energy storage capacitor and inductor L M With sharpening inductance L tr The other end is connected to the energy storage capacitor C M Keep away from energy storage capacitor and inductor L M end of.

5. The method for transient calibration of electric field sensors in a substation according to claim 4, characterized in that: The generating of the trigger signal and controlling the sharpening circuit to generate the high-voltage pulse signal comprises the following steps: Use a DC high voltage source to supply energy to the energy storage capacitor C M Charge to U0, and discharge to load resistor R through main switch K under trigger condition; When the main switch K is turned on at t=0, the calculation formula of the circuit equation is as follows: Where, L is the total distributed inductance of the circuit; R is the load resistance; C tr is a sharpening capacitor with energy storage function; t is time; i is the current in the circuit; Assume that the energy storage capacitor C M The voltage drop across is u c (t), using the initial condition I0 = 0, u c (0) = U0 to calculate the critical ratio. The calculation formula of the critical ratio is as follows: Wherein, α is the critical ratio, when α < 1, it is underdamped, when α = 1, it is critically damped, when α > 1, it is overdamped; R is the load resistance; C M is the energy storage capacitor; L is the total distributed inductance of the circuit; When the critical ratio α>>1, the specific formula for the current flowing through the load resistor R is as follows: Where I0(t) is the current flowing through the load resistor R; U R is the voltage of the load resistor R; R is the load resistor; Rc is the time constant of the charging circuit; L is the total distributed inductance of the circuit; U0 is the initial voltage; τ2 is the resistance-capacitance time constant; τ1 is the inductance-resistance time constant; The specific formula after the voltage of the load resistor R is reduced is as follows: Wherein, U0(t) is the voltage after the voltage of the load resistor R is reduced; The specific formula for rise time is as follows: Among them, t r is the rise time; t1 is the characteristic time parameter; The specific formula for the fading time is as follows: t f ≈2.2t2=2.2RC M Among them, t f is the fading time; t2 is the characteristic time parameter; The specific formula for half-height width is as follows: τ 0.5 ≈0.7C M R Among them, τ 0.5 is the half-height width.

6. The method for transient calibration of electric field sensors in a substation according to claim 5, characterized in that: The step of generating an electric field in the test space and instantaneously calibrating the electric field sensor comprises the following steps: Install different types of sensors in the test space to measure the electric field, magnetic field generated by the simulator, the electric field, magnetic field and waveform inside the test body; Transmit various analog data outside the anechoic chamber, and display, read and store the data through an oscilloscope; When instantaneously calibrating the electric field sensor, a distributed terminal matching load resistor is used.

7. The method for transient calibration of electric field sensors in a substation according to claim 6, characterized in that: The transient calibration parameters of the electric field sensor include peak field intensity, rising edge and oscilloscope; The effective use space of the anechoic chamber is 1 / T of the actual height of the anechoic chamber.

8. A substation electric field sensor transient calibration system, based on a substation electric field sensor transient calibration method according to any one of claims 1 to 7, characterized in that: include, The data acquisition module is used to obtain the transient calibration parameters and structural dimensions of the electric field sensor, and analyze the effective use space of the anechoic chamber to obtain the test space dimensions; Theoretical value module, used to calculate according to transient calibration parameters, structural dimensions and test space dimensions to obtain the theoretical value range of DC high voltage value; The AC mains module is used to process the AC mains according to the theoretical value range of the DC high voltage value to obtain a high-voltage DC power supply that meets the theoretical value range of the DC high voltage value; High-voltage pulse module, used to adjust the working data of the high-voltage DC power supply and control the sharpening circuit to generate a high-voltage pulse signal; The transient calibration module is used to transmit the high-voltage pulse signal to the test transmission line, generate an electric field that meets the test requirements in the test space, and instantaneously calibrate the electric field sensor in the test space.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for transient calibration of a substation electric field sensor according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for transient calibration of a substation electric field sensor according to any one of claims 1 to 7 are implemented.

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