Introduction to High-Voltage Dividers

2025-04-16 10:16:49 Billy

Introduction to High-Voltage Dividers

1. Basic Concept

A high-voltage divider is a device used to measure or distribute high voltages, capable of reducing voltages ranging from kilovolts to megavolts to a safe, measurable low-voltage range (e.g., volts or millivolts). Its core function is to achieve linear conversion between high and low voltages, making it widely applicable in power systems, high-voltage laboratories, pulsed power technologies, and more.

2. Structure

1，High-voltage arm: Composed of high-resistance resistors or capacitors in series to withstand the majority of the input high voltage.

2，Low-voltage arm: Low-resistance resistors or capacitors that output the divided low-voltage signal for measurement.

3，Shielding: Prevents corona discharge and electromagnetic interference, typically using grading rings, insulating enclosures, or metallic shielding layers.

3，Working Principle

Based on Ohm’s Law or capacitive voltage division:

1，Resistive divider: Voltage is divided by the ratio of the high-voltage arm (R1R1) to the low-voltage arm (R2R2), with output

V^{o u t} = V^{in} \times \frac{R ^{2}}{R ^{1} + R ^{2}}

2，Capacitive divider: Uses capacitive impedance for AC or pulsed high voltages, where output is inversely proportional to capacitance values.

4，Types and Features

Type	Features	Applications
Resistive Divider	Simple design, limited frequency response (due to parasitic capacitance).	DC or low-frequency voltage measurement.
Capacitive Divider	No DC losses, excellent frequency response, but requires dielectric loss considerations.	AC, high-frequency, or pulsed voltages.
RC Divider	Combines resistors and capacitors for optimized wideband response.	Lightning impulses, switching transients.

5，Typical Applications

1，High-voltage labs: Measuring impulse voltages (e.g., lightning waveforms) or power-frequency withstand tests.

2，Power systems: Monitoring insulation status in transmission lines or substation equipment.

3，Pulsed power: Precision control of high-voltage pulses in fusion devices or lasers.

4，Medical equipment: High-voltage monitoring in X-ray machines or particle accelerators.

6，Technical Considerations

1，Accuracy & Stability: High-voltage arms require low-temperature-coefficient materials (e.g., metal-film resistors, ceramic capacitors) to minimize drift.

2，Frequency Response: High-frequency applications demand reduced parasitic inductance/capacitance (e.g., coaxial or distributed parameter designs).

3，Insulation: Uses epoxy resin, SF6 gas, or oil immersion to prevent surface discharges.

4，Shielding & Grading: Optimizes electric field distribution via grading rings or segmented shielding to avoid partial discharges.

7，Key Q&A

Q: How does a high-voltage divider differ from a conventional divider?

A: High-voltage dividers require specialized designs for insulation strength, thermal management (due to Joule heating in high-resistance arms), and EMC, whereas conventional dividers are for low-voltage circuits.

Q: How to choose a divider type?

A: Select based on measurement requirements:

DC → Resistive divider

AC/pulsed → Capacitive or RC divider

Broadband signals → Hybrid RC design

8，Future Trends

1，Digitalization: Integration of fiber-optic transmission or digital interfaces for direct signal output.

2，Compact Design: Use of nanomaterials or solid-state insulation to reduce size.

3，High Precision: Enhanced stability via self-calibration circuits and temperature compensation.

As a critical sensor in high-voltage engineering, the design and selection of dividers must balance voltage levels, frequency ranges, and environmental conditions to ensure measurement accuracy and operational safety.

Lable: Introduction to High-Voltage Dividers

Introduction to High-Voltage Dividers

Introduction to High-Voltage Dividers

1. Basic Concept

2. Structure

3，Working Principle

Based on Ohm’s Law or capacitive voltage division:

4，Types and Features

5，Typical Applications

6，Technical Considerations

7，Key Q&A

8，Future Trends

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