A high-precision high-voltage voltage divider with adjustable voltage division ratio

Abstract

This invention discloses a high-precision adjustable voltage divider, belonging to the field of high-voltage electrical measurement technology. It includes a high-voltage arm body, a low-voltage precision resistor module, an adjustable potentiometer, and a housing. The high-voltage arm body is a series of high-resistance, medium-precision resistors, undertaking the main high-voltage voltage division. The low-voltage precision resistor module is connected in series at the end of the high-voltage arm for coarse adjustment to correct resistance deviations and improve basic accuracy. The adjustable potentiometer is connected in series or parallel to the low-voltage precision resistor module circuit, with its adjustment terminal exposed in the housing, for final precise calibration of the voltage division ratio. The high-voltage arm body and the low-voltage precision resistor module are integrally insulated and sealed, with only the adjustable potentiometer's adjustment terminal exposed, thus not affecting high-voltage insulation performance. This invention solves the problems of difficult accuracy control, lack of on-site fine-tuning, low production yield, and high calibration costs of traditional high-voltage dividers by using a three-stage resistance adjustment architecture of main body voltage division + precision module coarse adjustment + potentiometer fine adjustment, combined with flexible series and parallel adjustment methods. It can quickly calibrate the voltage division ratio to metrological-grade accuracy, is structurally safe, easy to debug, and highly versatile, suitable for DC, AC, and RC high-voltage dividers.

Description

1. Technical Field

[0002] This invention relates to the field of high-voltage electrical measurement equipment technology, specifically to a high-voltage divider structure with graded resistance adjustment, external precision fine-tuning, and support for flexible series and parallel adjustment. 2. Background Technology

[0004] High voltage dividers are core measuring devices in the fields of power systems, high voltage testing, and metrological verification. They are used to attenuate DC or AC high voltage into low voltage small signals at a fixed ratio, so as to achieve safe and accurate measurement.

[0005] Existing traditional high-voltage dividers generally suffer from the following technical defects: 1) The high-voltage arm is composed of a large number of high-resistance resistors connected in series. Affected by component dispersion, assembly errors, temperature and voltage coefficient, the overall resistance accuracy is low, making it difficult to directly meet metrological requirements; 2) The low-voltage arm mostly uses fixed resistors, which cannot be adjusted again once packaged. The voltage division ratio error can only be controlled by the initial resistor screening, resulting in low production qualification rate and high debugging cost; 3) When the voltage division ratio deviates due to component aging, temperature drift, and vibration during long-term use, it cannot be accurately corrected online or on-site, affecting the accuracy and reliability of measurement; 4) If ultra-high precision resistors are used throughout, it will significantly increase material costs and process difficulty, making it unsuitable for large-scale production; 5) Existing adjustable structures are mostly single series or single parallel connections, with fixed adjustment methods, which cannot balance adjustment range and fine-tuning accuracy.

[0006] Therefore, there is an urgent need for a high-voltage divider solution that is simple in structure, cost-controllable, graded adjustable, supports external precise fine-tuning, and is compatible with both series and parallel adjustment modes. 3. Summary of the Invention

[0008] 3.1 Purpose of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a three-stage adjustable high-voltage divider consisting of a high-voltage arm precision main body, a low-voltage precision module for coarse adjustment, and an external potentiometer for fine adjustment. It is also compatible with series / parallel dual adjustment modes, achieving low-cost, high-efficiency, and high-precision voltage divider ratio calibration, while meeting the needs of production, laboratory, and field calibration.

[0010] 3.2 Technical Solution

[0011] A high-precision adjustable voltage divider consists of four parts: 1) The high-voltage arm is composed of several high-resistance resistors connected in series, with a resistance in the megohm range and an accuracy of ±0.5% to ±1%, capable of withstanding over 95% of the high voltage, achieving basic voltage division, and reducing the ultra-high precision requirements of the high-voltage side components.

[0012] 2) The low-voltage precision resistor module consists of high-precision, low-temperature drift resistors connected in series, with an accuracy better than ±0.05%. It is directly connected in series with the high-voltage arm body and is used to coarsely adjust and correct the resistance deviation of the high-voltage arm body, so as to quickly increase the voltage division ratio to close to the target value.

[0013] 3) Adjustable potentiometer (series / parallel compatible): Employs a multi-turn, high-precision adjustable potentiometer, which can be connected in series or parallel to the low-voltage precision resistor module circuit.

[0014] Series mode: The potentiometer is connected in series at the rear end of the low-voltage precision resistor module, and the voltage division ratio can be finely adjusted by changing the total resistance of the low-voltage arm;

[0015] Parallel mode: The potentiometer is connected in parallel across the two ends of the low-voltage precision resistor module. The voltage division ratio is calibrated with high precision by finely adjusting the shunt ratio. The adjustment terminal is exposed outside the package housing for final fine adjustment and locking.

[0016] 4) The integrated encapsulation housing adopts an insulated and sealed housing to encapsulate and fix the high voltage arm body and the low voltage precision resistor module as a whole, ensuring high voltage insulation strength, moisture resistance and mechanical stability; only the adjustable potentiometer adjustment terminal is exposed to achieve safe fine adjustment.

[0017] 3.3 Calibration Principle

[0018] The main body of the high-voltage arm provides the basic voltage distribution ratio;

[0019] The low-voltage precision resistor module compensates for the resistance error of the main body and completes the coarse adjustment;

[0020] Apply standard high voltage and measure the low voltage output signal;

[0021] Fine adjustment can be made using an exposed adjustable potentiometer in series or parallel connection.

[0022] Once the partial pressure ratio reaches the target accuracy, it is locked, and calibration is complete.

[0023] 3.4 Core Invention Points

[0024] 1) The high-voltage segmented resistance adjustment architecture adopts a high-resistance, medium-precision design on the high-voltage side to reduce costs and process difficulty; the low-voltage side adopts a precision module + adjustable potentiometer to achieve progressively improved precision.

[0025] 2) External adjustable potentiometer fine adjustment: Without damaging the high voltage insulation or affecting the withstand voltage performance, the voltage division ratio can be accurately calibrated by adjusting the resistance within a small range on the low voltage side.

[0026] 3) The series and parallel dual adjustment mode is compatible with the series wide-range adjustment and the parallel high-precision fine adjustment, adapting to different voltage division ratios and accuracy requirements.

[0027] 4) The high-voltage section is fully sealed in an integrated sealed package, ensuring safety and reliability; the debugging end is exposed, facilitating factory calibration, periodic verification, and on-site maintenance.

[0028] 5) The three-level accuracy improvement path, namely the main body voltage divider → precision module coarse adjustment → potentiometer fine adjustment, can optimize the voltage divider ratio error from more than 0.5% to within 0.05%, meeting the metrological verification requirements. 4. Detailed Implementation

[0030] Example 1: Series regulation mode (100kV DC high voltage divider, voltage division ratio 10000:1)

[0031] 1) High-voltage arm main body: multiple high-resistance resistors connected in series, with a total resistance of approximately 999 MΩ and an accuracy of ±0.5%; 2) Low-voltage precision resistor module: ±0.01% high-precision resistors, with a total resistance of approximately 9.9 kΩ; 3) Adjustable potentiometer: a 100Ω multi-turn high-precision potentiometer connected in series at the rear end of the low-voltage module; 4) Encapsulation: the high-voltage arm and the low-voltage module are potted and insulated, with the potentiometer adjustment terminal exposed; 5) Calibration: a standard high voltage is applied, and the potentiometer is adjusted to achieve a voltage division ratio of 10000:1.

[0032] Example 2: Parallel regulation mode (100kV DC high voltage divider, voltage division ratio 10000:1)

[0033] 1) High-voltage arm main body: Same as in Example 1; 2) Low-voltage precision resistor module: Same as in Example 1; 3) Adjustable potentiometer: Connected in parallel across the low-voltage precision resistor module, achieving high-precision calibration through fine-tuning of the shunt; 4) Smoother adjustment and higher stability, suitable for correction of extremely small errors.

[0034] 5. Beneficial effects

[0035] 1) High precision: Three-stage resistance adjustment can quickly achieve metering-grade accuracy, with a voltage divider ratio error ≤0.05%; 2) Low cost: The high-voltage arm does not require ultra-high precision, reducing resistor screening and material costs; 3) High debugging efficiency: Calibration can be completed in one package, resulting in high production pass rate and short cycle; 4) On-site calibration: Exposed potentiometers support factory, periodic verification, and multiple fine-tuning on-site; 5) Safe and reliable: The high-voltage section is fully sealed, ensuring no degradation in insulation performance. Debugging is performed on the low-voltage side, eliminating high-voltage risks; 6) Flexible adjustment: Compatible with both series wide-range and parallel high-precision modes; 7) Strong versatility: Applicable to DC high-voltage dividers, AC high-voltage dividers, and resistive-capacitive dividers. 6. Description of the attached drawings

[0037] Figure 1 is a schematic diagram of the overall structure of the series mode of the present invention; Figure 2 is a schematic diagram of a partial structure of the parallel mode of the present invention.

[0038] Figure 1. Labels: 1— High voltage input terminal; 2— High voltage arm body; 3— Low voltage precision resistor module; 4— Adjustable potentiometer (in series); 5— Exposed adjustment terminal; 6— Package housing; 7— Low voltage output terminal.

[0039] Figure 2 Labels: 3—Low-voltage precision resistor module; 4—Adjustable potentiometer (in parallel).

Claims

1. A high-precision adjustable voltage divider, characterized in that, include: The system comprises a high-voltage arm body, a low-voltage precision resistor module, an adjustable potentiometer, and a housing. The high-voltage arm body is composed of high-resistance resistors connected in series to withstand high voltage and achieve basic voltage division. The low-voltage precision resistor module is connected in series with the high-voltage arm body to initially correct resistance deviations and improve the basic accuracy of the voltage division ratio. The adjustable potentiometer is connected in series or parallel to the circuit containing the low-voltage precision resistor module, and its adjustment terminal is exposed outside the housing. The high-voltage arm body and the low-voltage precision resistor module are sealed within the housing, with only the adjustment terminal of the adjustable potentiometer exposed.

2. The high-voltage divider according to claim 1, characterized in that, The high-voltage arm body has a megohm-level high resistance with an accuracy of ±0.5% to ±1%; the low-voltage precision resistor module has an accuracy better than ±0.05% and is used to compensate for the resistance dispersion error of the high-voltage arm body.

3. The high-voltage divider according to claim 1, characterized in that, The adjustable potentiometer is a multi-turn high-precision potentiometer, with an adjustment range covering the remaining voltage division ratio error, achieving final accurate calibration and locking of the voltage division ratio.

4. The high-voltage divider according to claim 1, characterized in that: When the adjustable potentiometer is connected in series, it is used to finely increase or decrease the total resistance of the low-voltage arm; when the adjustable potentiometer is connected in parallel, it is used to finely shunt or attenuate the total resistance of the low-voltage arm.

5. The high-voltage divider according to claim 1, characterized in that, The encapsulation housing is an insulated potting structure, with the high-voltage arm body and the low-voltage precision resistor module being completely sealed, and only the adjustable potentiometer adjustment terminal being exposed, ensuring high-voltage insulation and mechanical strength.

6. The high-voltage divider according to claim 1, characterized in that, The voltage divider ratio calibration process is as follows: voltage divider of the high-voltage arm main body → coarse adjustment and correction of the low-voltage precision resistor module → fine adjustment and locking of the adjustable potentiometer in series / parallel, gradually adjusting the voltage divider ratio to the target measurement accuracy.

7. The high-voltage divider according to claim 1, characterized in that, Suitable for DC high voltage dividers, AC high voltage dividers, and RC dividers.

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