Non-contact voltage sensor device

Abstract

A non-contact voltage sensor device is provided with: a probe electrode (10) for observing an AC voltage generated in a cable having a cable conductor and a coating material for coating the cable conductor, without performing electrode connection; an impedance circuit (14) that is connected to the probe electrode and has a first resistance element (142) that simulates the insulation resistance of the coating material, a first capacitor element (141) that simulates the coupling capacitance generated between the cable conductor and the probe electrode, and a dielectric relaxation simulation circuit (143) that simulates the dielectric relaxation generated in the coating material, the first resistance element, the first capacitor element, and the dielectric relaxation simulation circuit being connected in parallel to each other; and an operational amplifier (15), the positive electrode input terminal of which is connected to the reference potential point, the negative electrode input terminal of which is connected to the input point of the impedance circuit, and the output terminal of which is connected to the output point of the impedance circuit, the dielectric relaxation analog circuit having at least one snubber circuit (SC, SC1-SC3) having a series connection of second resistive elements (1431, 51-53) and second capacitor elements (1432, 61-63).

Description

Technical Field

[0001] This invention relates to a non-contact voltage sensor device. Background Technology

[0002] Conventional techniques exist that observe the AC voltage of a cable core without bringing the probe electrodes into contact with it. In such non-contact observations, a small coupling capacitance is generated between the cable core and the probe electrodes, causing the components on the sensor circuit side to become highly impedance compared to this coupling capacitance. If a component on the sensor circuit side has a real part of a complex impedance, such as the input resistance of an operational amplifier, the phase of the AC voltage waveform being observed will rotate, making high-precision observation impossible.

[0003] To address the aforementioned issues, for example, the non-contact voltage sensor device described in Patent Document 1 includes a frequency compensation circuit that compensates for the frequency characteristics of the amplitude and phase of the AC voltage waveform. This frequency compensation circuit is configured to include an impedance circuit and an operational amplifier. The impedance circuit simulates the complex impedance from the cable core to the input terminal. Therefore, even if the coupling capacitance generated between the probe electrode and the cable core is small, the components on the sensor circuit side will not become high-impedance, thus suppressing accuracy degradation such as phase rotation of the observed waveform.

[0004] Patent Document 1: Japanese Patent No. 7003338 Summary of the Invention

[0005] However, according to the existing device, there is a problem that the dielectric relaxation effect generated by the sheathing material of the cable core is not taken into account, and the error caused by the frequency characteristics of the resulting coupling capacitance will be included in the observed waveform.

[0006] The present invention was proposed to solve the above-mentioned problems, and its purpose is to provide a non-contact voltage sensor device that can suppress the errors contained in the observed waveform compared with the past.

[0007] One embodiment of the non-contact voltage sensor device according to the present invention includes: a probe electrode for observing an AC voltage generated in a cable without electrode connection, the cable having a cable conductor and a covering material covering the cable conductor; an impedance circuit connected to the probe electrode, having a first resistive element, a first capacitor element, and a dielectric relaxation simulation circuit connected in parallel, the first resistive element simulating the insulation resistance of the covering material, the first capacitor element simulating the coupling capacitance generated between the cable conductor and the probe electrode, and the dielectric relaxation simulation circuit simulating the dielectric relaxation generated in the covering material; and an operational amplifier connected to the output point of the impedance circuit, the positive input terminal of the operational amplifier connected to a reference potential point, the negative input terminal of the operational amplifier connected to the input point of the impedance circuit, and the output terminal of the operational amplifier connected to the output point of the impedance circuit, the dielectric relaxation simulation circuit having at least one buffer circuit configured such that a second resistive element different from the first resistive element and a second capacitor element different from the first capacitor element are connected in series.

[0008] The effects of the invention

[0009] According to an embodiment of the present invention, the impedance circuit of the non-contact voltage sensor device has a dielectric relaxation simulation circuit that simulates the dielectric relaxation generated in the coating material. Therefore, the effect of dielectric relaxation can be taken into account, and the error that may be contained in the observed waveform can be suppressed compared with the past. Attached Figure Description

[0010] Figure 1A This is a block diagram illustrating the structure of the non-contact voltage sensor device according to Embodiment 1.

[0011] Figure 1B This is a diagram illustrating a structural example of the dielectric relaxation analog circuit according to Embodiment 1.

[0012] Figure 2 This represents the measured and simulation results of the frequency characteristics of a non-contact voltage sensor device due to dielectric relaxation.

[0013] Figure 3 Is Figure 2 The circuit diagram of the non-contact voltage sensor device used as a comparative example in the actual measurement and simulation is shown. This non-contact voltage sensor device as a comparative example does not have a dielectric relaxation compensation circuit.

[0014] Figure 4 This is a circuit diagram showing the structure of a modified example of the dielectric relaxation analog circuit according to Embodiment 1.

[0015] Figure 5 This is a flowchart illustrating the correction process of the dielectric relaxation analog circuit involved in a variation of Embodiment 1.

[0016] Figure 6 This is a conceptual diagram illustrating the effect of the dielectric relaxation analog circuit involved in Implementation Method 1. Detailed Implementation

[0017] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, structural elements labeled with the same or similar reference numerals in the drawings have the same or similar structures or functions, and repeated descriptions of these structural elements are omitted. Additionally, in the present invention, unless otherwise specified, the term "or" is used in the sense of either / or.

[0018] Implementation Method 1

[0019] <Structure>

[0020] Reference Figure 1A and Figure 1B The non-contact voltage sensor device 1 according to Embodiment 1 of the present invention will be described. Figure 1A This is a block diagram showing the structure of the non-contact voltage sensor device 1 according to Embodiment 1. Figure 1B This is a diagram illustrating an example of the structure of the electrical relaxation analog circuit 143 in the non-contact voltage sensor device 1.

[0021] exist Figure 1A In this cable, cables 2A and 2B constitute a pair of two wires. Cable conductor 2a is the core wire of each cable 2A and cable 2B. The cable sheath 2b is the insulating covering material that encloses the cable conductor 2a in cables 2A and 2B. AC voltage V in This voltage is generated in cable conductor 2a by supplying power from AC power source 3 to cable conductor 2a. One terminal of AC power source 3 is connected to cable conductor 2a of cable 2A, and the other terminal of AC power source 3 is connected to a reference potential point. Cable conductor 2a of cable 2B becomes the reference potential (e.g., ground potential).

[0022] The non-contact voltage sensor device 1 has a probe electrode 10, a probe cable 11, and a sensor circuit 12. The non-contact voltage sensor device 1 measures the AC voltage V of the cable conductor 2a. in The waveform is observed. Probe electrode 10 is used to measure the AC voltage V generated in cable 2A without electrode connection. inThe observation probe includes a cable 2A having a cable conductor 2a and a covering material 2b covering the cable conductor 2a. A probe electrode 10 is connected to one end of a probe cable 11, and the other end of the probe cable 11 is connected to a sensor circuit 12. The probe electrode 10 is disposed on the cable covering portion 2b of the cable 2A. The probe electrode 10 is disposed with respect to the cable covering portion 2b and is not in contact with the cable conductor 2a. Alternatively, the probe electrode 10 may be disposed in contact with the cable covering portion 2b or disposed at a small distance from it.

[0023] like Figure 1A As shown, a coupling capacitance C0 is generated between the cable conductor 2a and the probe electrode 10. For example, the coupling capacitance C0 generated between the probe electrode 10 with a length and width of 1 (cm) and the cable conductor 2a is a small capacitance of about a few (pF).

[0024] Resistor R0 is a pull-down resistor provided to prevent the node potential inside sensor circuit 12 from becoming unstable under DC. One end of the resistive element with resistor R0 is connected to input point A of impedance circuit 14, and the other end of the resistive element is connected to the reference potential point.

[0025] The sensor circuit 12 includes a frequency compensation circuit 13 and an AD converter 16. The frequency compensation circuit 13 includes an impedance circuit 14 and an operational amplifier 15. The impedance circuit 14 includes: a capacitor element 141 having a capacitance C1; a resistor element 142 having a resistance R1; and a dielectric relaxation analog circuit 143.

[0026] The input terminals of AD converter 16 are connected to the output terminals of operational amplifier 15, and the output terminals of AD converter 16 are connected to... Figure 1A The connection of the subsequent stage devices (not shown in the diagram). The output of the operational amplifier 15 from the frequency compensation circuit 13 represents the AC voltage V. out The analog signal is input to the A / D converter 16. The A / D converter 16 will convert the AC voltage V... out The analog signal is converted into a digital signal, and the converted digital signal is output to the subsequent device.

[0027] A probe cable 11, connected to the probe electrode 10, is connected to input point A of impedance circuit 14. The output point of impedance circuit 14 is connected to the output terminal of operational amplifier 15. The positive input terminal of operational amplifier 15 is connected to the reference potential point (ground), and the negative input terminal of operational amplifier 15 is connected to input point A of impedance circuit 14. Thus, input point A of impedance circuit 14 is virtually short-circuited.

[0028] The observation system from probe electrode 10 to input point A of impedance circuit 14 is virtually short-circuited by operational amplifier 15. At this time, operational amplifier 15 outputs an AC voltage that cancels out the AC voltage detected by probe electrode 10, making the positive and negative input terminals the same voltage. That is, operational amplifier 15 outputs an AC voltage V... out The waveform follows the AC voltage V, which is the object of observation, in a phase-reversed (out-of-phase) state. in It operates in a waveform manner.

[0029] The AD converter 16 receives the AC voltage V from the output of the operational amplifier 15. out The analog signal is used as input, and the received analog signal is converted into a digital signal. The digital signal after conversion by the AD converter 16 is in the form of an AC voltage V. in The inverted state. The device after the AD converter 16 inverts the sign of the digital signal, thereby obtaining the observed waveform.

[0030] In impedance circuit 14, capacitor element 141 and resistor element 142 are connected in parallel with dielectric relaxation simulation circuit 143. In addition, capacitor element 141 and resistor element 142 are also connected in parallel with each other.

[0031] The complex impedance Z of impedance circuit 14 int The complex impedance Z is composed of the capacitance C1 of capacitor element 141, the resistance R1 of resistor element 142, and the impedance simulated by dielectric relaxation simulation circuit 143. int Simulate the complex impedance Z of the observation system from cable conductor 2a to input point A of impedance circuit 14. obs Here, the complex impedance Z of the observation system obs This includes the dielectric relaxation effect generated by the coating material. Furthermore, the complex impedance of resistance R0 is not included in the complex impedance Z. obs The impedance is simulated.

[0032] Capacitor element 141 is a capacitor element that simulates the coupling capacitance C0, and the coupling capacitance C0 and the capacitance C1 of capacitor element 141 are equivalent. For example, a capacitor element equivalent to the measured value of the coupling capacitance C0 and the capacitance C1 is selected as capacitor element 141. Resistor element 142 is an element that simulates the insulation resistance of the cable sheath 2b, and the insulation resistance of the cable sheath 2b and the resistance R1 of resistor element 142 are equivalent. For example, the insulation resistance of the cable sheath 2b is estimated in advance based on the insulation material of the cable sheath 2b and the dimensions of the probe electrode 10. This resistor element, which is equivalent to the insulation resistance and the resistance R1, is selected as resistor element 142.

[0033] The complex impedance Z of impedance circuit 14int The complex impedance Z relative to the observation system obs Equations (1) and (2) below hold true. In equation (1), V in It is the AC voltage V of conductor 2a of the cable. in The amplitude of V. out The gain G is the amplitude of the AC voltage observed by the sensor circuit 12. In the following equation (2), the gain G is the gain of the AC voltage observed by the sensor circuit 12, and is a real value.

[0034]

[0035] In the above equation (2), the complex impedance Z of the impedance circuit 14 int The complex impedance Z of the observation system obs A real number multiple (G times). Furthermore, as shown in equation (1) above, V out Depends on complex impedance Z int The value of V is amplified or attenuated by inverting the gain G. out When performing inverted amplification, the gain G becomes a real number greater than 1, and the complex impedance Z... int Becomes more complex impedance Z obs Large. In complex impedance Z int It is the complex impedance Z obs In the case of a real multiple, AC voltage V in and AC voltage V out The phase difference of the waveform becomes zero.

[0036] In the non-contact voltage sensor device 1 according to Embodiment 1, there is an AD converter 16, which converts the analog signal output from the output terminal of the operational amplifier 15 into a digital signal and outputs the converted digital signal. The device after the AD converter 16 inverts the sign of the digital signal, thereby obtaining the observed waveform of the AC voltage.

[0037] Here, we will explain the dielectric relaxation generated in the cable sheathing material of the observed object. Cable sheathing materials widely use dielectrics with high electrical insulation. Dielectrics have a wide bandgap, therefore there are no free electrons, and even when a DC voltage is applied, no electron flow (current) occurs. On the other hand, dielectric polarization occurs with respect to the applied voltage (electric field), inducing electric dipoles, so polar molecules orient themselves following the electric field applied from the outside. However, with respect to high-frequency changes in the electric field, the orientation response is delayed, and molecular-level heating becomes the main cause of dielectric loss. The phenomenon that produces frequency characteristics in the dielectric constant corresponding to this delay in the orientation response is called dielectric relaxation. If dielectric relaxation occurs in the cable sheathing material, the coupling capacitance generated between the probe electrode and the cable core also produces frequency characteristics, thus becoming a major cause of deterioration in observation accuracy.

[0038] The insulation materials for power cables are typically made of polymers such as polyvinyl chloride (PVC). Due to the covalent bonds between chlorine and carbon chains in these polymers, dielectric polarization occurs, which is the primary cause of the aforementioned dielectric relaxation. Therefore, compensation for the effects of dielectric relaxation is necessary. On the other hand, the polyethylene or Teflon materials used in the dielectric materials of high-frequency cables do not exhibit dielectric polarization and do not experience precision degradation caused by dielectric relaxation. Therefore, in this case, compensation for the effects of dielectric relaxation is not required.

[0039] Modeling the electrical (frequency) characteristics associated with dielectric relaxation of a dielectric material using a buffer (CR) type circuit is a known technique (Japanese Patent Application Publication No. 2020-107985). On the other hand, in non-contact voltage measurements, the extent to which the dielectric relaxation of the polyvinyl chloride (PVC) of the observed cable affects the measurement accuracy is generally unclear. This is because the influence of factors such as relaxation time, frequency, and degradation can vary depending on the PVC manufacturing process (degree of polymerization), the composition of additives, and the amount of additives used.

[0040] Figure 2 It means Figure 3 The figure shows the measured and simulated results of the frequency characteristics of the amplitude of a non-contact voltage sensor device C without dielectric relaxation compensation circuitry. Figure 2 In this context, "measurements" represents the measured results, and "numerical" represents the simulation results. Figure 3The non-contact voltage sensor device C shown is a comparative example. For the cable being observed, the sheathing material used is polyvinyl chloride (PVC), which generates dielectric polarization. At frequencies above approximately 0.5 kHz, the measured results deviate from the simulation results. The simulation does not consider the dielectric relaxation effect, showing a flat frequency response. On the other hand, the measured results include the dielectric relaxation effect of PVC; the amplitude decreases as the frequency increases. This deviation between the measured and simulation results is a new problem recognized for the first time by the inventors of this invention. This deviation is a non-negligible error in non-contact voltage observation; therefore, this invention discloses a method for correcting this deviation, in other words, a method for compensating for the dielectric relaxation effect.

[0041] The non-contact voltage sensor device 1 according to Embodiment 1 is a device capable of compensating for the effect of dielectric relaxation. The non-contact voltage sensor device 1 includes a dielectric relaxation simulation circuit 143, which compensates for the effect of dielectric relaxation generated in the cable sheath 2b. By modeling the effect of dielectric relaxation, a complex impedance Z is obtained. int Become the complex impedance Z obs The compensation is performed in a manner that is a multiple of the real number. As a result, even when dielectric relaxation occurs in the cable covering portion 2b, the non-contact voltage sensor device 1 can obtain frequency characteristics with flat amplitude and phase, thus improving the observation accuracy of the AC voltage waveform.

[0042] Figure 1B This is a diagram illustrating an example of the specific structure of the dielectric relaxation analog circuit 143. (See diagram for example.) Figure 1B As shown, as an example, the dielectric relaxation analog circuit 143 can be implemented as a buffer circuit SC that connects the resistive element 1431 and the capacitor element 1432 in series. The element constants of the resistive element 1431 or the capacitor element 1432 can also be variable.

[0043] Next, refer to Figure 4 A variation of the dielectric relaxation analog circuit 143 will be described. Figure 4 This is a circuit diagram showing a modified example of the dielectric relaxation analog circuit 143. For example... Figure 4 As shown, the dielectric relaxation analog circuit 143a, a variation of the dielectric relaxation analog circuit 143, includes a switching element 31, a switching element 41, a resistive element 51, a capacitor element 61, a switching element 42, a resistive element 52, a capacitor element 62, a switching element 43, a resistive element 53, a capacitor element 63, and a control circuit 70.

[0044] Switching element 31 is used to switch the connection between the dielectric relaxation simulation circuit 143a and the impedance circuit 14. Switching element 31 is used to enable or disable the function of the dielectric relaxation simulation circuit 143a. Switching element 31 is located upstream of the switching elements 41-43 within the dielectric relaxation simulation circuit 143a, and is therefore sometimes referred to as the main switching element in this invention. When measuring cables using dielectrically polarized materials as insulation, switching element 31 is set to ON to connect the dielectric relaxation simulation circuit 143a and the impedance circuit 14. When measuring cables using insulation materials that do not generate dielectric polarization, switching element 31 is set to OFF to electrically disconnect the dielectric relaxation simulation circuit 143a from the impedance circuit 14.

[0045] Resistive elements (second resistive elements) 51-53 and capacitor elements (second capacitor elements) 61-63 are installed to simulate the relaxation time. The series-connected resistive elements and capacitor elements constitute a buffer circuit (SC1-SC3). The element constant of any one or more of the resistive elements 51-53 and capacitor elements 61-63 can be variable. Furthermore, switching elements 41-43 are used to adjust the wideband characteristics of dielectric relaxation by switching these buffer circuits, i.e., combinations of connecting or disconnecting these elements. Switching elements 41-43 are located downstream of switching element 31 outside the dielectric relaxation simulation circuit 143a, and are therefore sometimes referred to as auxiliary switching elements in this invention.

[0046] As described above, the dielectric relaxation analog circuit 143a has multiple buffer circuits SC1 to SC3 connected in parallel with each other. Figure 4 The dielectric relaxation analog circuit 143a has three buffer circuits SC1 to SC3, but the number of buffer circuits can also be two, or more than or equal to four.

[0047] As described above, the dielectric relaxation analog circuit 143 or 143a of the present invention has at least one buffer circuit (SC; SC1 to SC3), which is configured such that a resistor element (1431; 51 to 53) different from the resistor element 142 and a capacitor element (1432; 61 to 63) different from the capacitor element 141 are connected in series.

[0048] In addition, in a modified example, the dielectric relaxation analog circuit 143a has multiple buffer circuits SC1 to SC3, and the multiple buffer circuits SC1 to SC3 are connected in parallel with each other.

[0049] Alternatively, the impedance circuit 14 may also have a switching element 31 for switching between the presence and absence of the dielectric relaxation simulation circuit 143 or 143a. Additionally, the dielectric relaxation simulation circuit 143a may also have switching elements (41 to 43) for switching between the presence and absence of each of the multiple buffer circuits SC1 to SC3.

[0050] Alternatively, any element constituting the buffer circuit (SC; SC1~SC3) can be an element with a variable element constant.

[0051] Next, refer to Figure 5 The processing flow of the dielectric relaxation analog circuit 143a is explained. Figure 5 The processing flow of the dielectric relaxation analog circuit 143a is shown. Figure 5 The processing procedure is carried out by the person conducting the measurement.

[0052] In step ST1, the probe electrode 10 is mounted on the object being observed. That is, the probe electrode 10 is positioned on the cable sheath 2b of the cable 2A. To ensure high observation accuracy, a large coupling capacitance C0 is advantageous, and it is preferably configured to minimize the gap between the probe electrode 10 and the cable 2A.

[0053] In step ST2, a coupling capacitance determination process is performed as a pre-processing step. This process is used to determine the coupling capacitance C0 using a known test signal. The determined coupling capacitance C0 is then used in the calculation of the gain G as needed.

[0054] In step ST3, it is determined whether the sheathing material used in the cable 2A, which is the object of observation, has dielectric polarization.

[0055] Corresponding to the determination result in step ST3, the switch element 31 is selected to be either On (step ST5) or Off (step ST4). In the case of polymer materials such as PVC that produce dielectric relaxation, On is selected, and the process proceeds to the calibration process (steps ST6 to ST11). On the other hand, in the case of materials such as Teflon that do not produce dielectric relaxation, Off is selected, and the process proceeds to the measurement process (ST12).

[0056] In the calibration process (steps ST6 to ST11), firstly, in step ST6, the initial settings of the switching elements (41 to 43) are performed. Here, as the initial state, for example, only the switching element 41 is set to the On state. Next, a known signal is applied to the cable, and the flatness of the frequency response is evaluated. The known signal is, for example, a scanning sine wave. If the flatness of the frequency response is ensured in the first attempt (step ST8; Yes), the process proceeds to the measurement process (step ST12). If the flatness is not ensured (step ST8; No), the switching elements (41 to 43) are switched to other structures, and the flatness of the frequency response is evaluated. This process is repeated until the flatness of the frequency response is ensured. If the flatness of the frequency response is ensured (step ST8; Yes), the process proceeds to the measurement process. If the flatness of the frequency response is not ultimately ensured (step ST10; Yes), the flattest switching structure is selected in step ST11, and the process proceeds to the measurement process (step ST12).

[0057] pass Figure 5 The processing flow shown selects a combination of dielectric relaxation compensation elements suitable for the characteristics of the insulation material of the cable being observed. That is, the non-contact voltage sensor device 1 of this invention can suppress the accuracy degradation of the observed waveform caused by the complex impedance of the observation system, including the dielectric relaxation effect generated by the cable sheathing material, and can obtain frequency characteristics with flat amplitude and phase.

[0058] In the non-contact voltage sensor device 1 according to Embodiment 1, the impedance circuit 14 corresponds to the complex impedance Z from the cable conductor 2a to the input point A. obs Simulations are performed using a real multiple of [a number]. Therefore, as [a number]... Figure 6 As shown, a flat frequency response is obtained, which suppresses the error in waveform observation. Figure 6 This is a conceptual diagram illustrating the effect of the dielectric relaxation simulation circuit involved in Implementation Method 1. Figure 6 Before the correction process, as shown by the dashed line, the high-frequency gain changes due to the effect of dielectric relaxation. However, after the correction process, the effect of dielectric relaxation is compensated by the dielectric relaxation simulation circuit 143, thus a flat frequency response is obtained as shown by the solid line.

[0059] Furthermore, it is possible to combine implementation methods and appropriately modify or omit each implementation method.

[0060] Industrial applicability

[0061] The non-contact voltage sensor device involved in this invention can be used, for example, to observe the AC voltage applied to power distribution cables.

[0062] Explanation of the label

[0063] 1. Non-contact voltage sensor device; 2A, 2B cables; 2a cable conductor; 2b cable sheath; 3. AC power supply; 10. Probe electrode; 11. Probe cable; 12. Sensor circuit; 13. Frequency compensation circuit; 14. Impedance circuit; 15. Operational amplifier; 16. AD converter; 31. Switching element (main switching element); 41-43. Switching elements (secondary switching elements); 51-53. Resistor element (secondary resistor element); 61-63. Capacitor element (secondary capacitor element); 70. Control circuit; 141. Capacitor element (first capacitor element); 142. Resistor element (first resistor element); 143. Dielectric relaxation simulation circuit; 143a. Dielectric relaxation simulation circuit; 1431. Resistor element (secondary resistor element); 1432. Capacitor element (secondary capacitor element); SC (SC1-SC3) buffer circuit.

Claims

1. A non-contact voltage sensor device, comprising: A probe electrode for observing the AC voltage generated in a cable without electrode connection, the cable having a cable conductor and a covering material covering the cable conductor; An impedance circuit, connected to the probe electrode, includes a first resistive element, a first capacitor element, and a dielectric relaxation simulation circuit connected in parallel. The first resistive element simulates the insulation resistance of the coating material, the first capacitor element simulates the coupling capacitance generated between the cable conductor and the probe electrode, and the dielectric relaxation simulation circuit simulates the dielectric relaxation generated in the coating material. An operational amplifier is connected to the output point of the impedance circuit. The positive input terminal of the operational amplifier is connected to a reference potential point, the negative input terminal is connected to the input point of the impedance circuit, and the output terminal is connected to the output point of the impedance circuit. The dielectric relaxation simulation circuit has at least one buffer circuit, which is configured such that a second resistive element different from the first resistive element and a second capacitor element different from the first capacitor element are connected in series.

2. The non-contact voltage sensor device according to claim 1, wherein, The at least one buffer circuit has multiple buffer circuits connected in parallel with each other.

3. The non-contact voltage sensor device according to claim 2, wherein, The dielectric relaxation simulation circuit has a secondary switching element connected in series with each buffer circuit, which is used to switch whether each buffer circuit is connected or not.

4. The non-contact voltage sensor device according to any one of claims 1 to 3, wherein, The second resistive element includes at least one variable resistive element, and the second capacitor element includes at least one variable capacitor element.

5. The non-contact voltage sensor device according to any one of claims 1 to 4, wherein, The impedance circuit also has a main switching element, which is used to switch whether the dielectric relaxation analog circuit is connected or not.

Images