What is a hipot test used for? Powerful 100kV Insulation Strength with Lisun HIPOT10-100KV

Abstract: Withstand voltage testing, also known as high insulation strength testing, is a core method for evaluating the safety of electrical equipment, electronic instruments, and insulating materials. By applying a voltage higher than the rated operating voltage of the equipment, the withstand voltage test aims to verify whether the insulation system possesses sufficient electrical strength to withstand transient overvoltages.

This paper systematically analyzes the physical mechanisms of withstand voltage testing, the characteristic differences between AC/DC testing, and relevant international and national standards (such as IEC 60664-1, GB/T 1408.1, etc.). Meanwhile, combining the technical characteristics of LISUN HIPOT series power frequency withstand voltage test equipment, this paper discusses the key role of autotransformer regulation, cascade connection technology, and overcurrent protection in improving test accuracy and safety.

1. Introduction

In electrical engineering and quality assurance systems, engineers often face a core question: What is a hipot test used for? Simply put, it is the ultimate check to measure whether electrical products can operate safely under extreme voltage stress. Whether it is precision optical measurement equipment or large power transformers, the reliability of their insulation system is directly related to personal safety and asset protection.

With the continuous evolution of global electrical standards, withstand voltage testing has evolved from a simple “breakdown check” in the early days to a comprehensive testing method integrating leakage current analysis, corona discharge monitoring, and insulation coordination assessment. This paper will deeply analyze the theoretical foundation of withstand voltage testing and the technical advantages of LISUN HIPOT series equipment based on academic and engineering practice.

2. Core Theory of Withstand Voltage Testing: Physical Mechanisms and Application Objectives

2.1 Verifying the Electrical Strength of the Insulation System

The primary purpose of withstand voltage testing is to verify the electrical strength of the dielectric (insulating material) by simulating an overvoltage environment. Under the action of electric field force, charged particles inside the insulating material will undergo directional movement. If the electric field strength E exceeds the breakdown threshold E_b of the material, an ionization avalanche will occur, leading to insulation failure.

2.2 Detecting Manufacturing Process Defects

In actual production, even with a perfect design, minor process flaws (such as burrs on wire edges, solder slag, bubbles inside the insulating material, or moisture residues) can cause local electric field distortion. High-voltage testing can force these weak points to be exposed in a controlled laboratory environment, thereby preventing catastrophic failure of products at the user end.

2.3 Evaluating Leakage Current Performance

Withstand voltage testing not only focuses on the instantaneous result of “breakdown” but also pays attention to the leakage current level throughout the entire pressurization process. By monitoring microampere-level current changes, the changing trend of insulation resistance can be inferred, thereby judging whether the insulation system has signs of aging or moisture absorption.

3. Technical Logic Comparison between AC and DC Withstand Voltage Testing

LISUN HIPOT series equipment (such as HIPOT10-100KV) has AC/DC dual testing capabilities to adapt to loads with different physical properties.

3.1 AC Withstand Voltage Testing (Power Frequency Withstand Voltage)

AC testing simulates the stress state of equipment in a real 50Hz/60Hz power grid. Its electric field direction changes periodically, which can simultaneously test both the resistive and capacitive components of the insulation layer.

• Physical Advantage: The positive and negative peaks of the test voltage can be reached, making the test stress more comprehensive than DC.
• Limitation: Reactive power is required. For high-capacitance samples, the test transformer must have a very large capacity.

3.2 DC Withstand Voltage Testing

DC testing is mainly used for high-capacitance loads, such as ultra-long power cables or large-capacity generator windings.

• Physical Advantage: After the initial charging is completed, only resistive leakage current flows through the insulator, making it easy to judge the insulation state by reading.
• Limitation: Deep residual charge discharge must be performed after the test, otherwise it will endanger the safety of the operator.

4. Strict Standard Compliance: The Compliance Foundation of Withstand Voltage Testing

LISUN HIPOT series equipment strictly follows the following international and national standards during the design and calibration process to ensure the test results have global credibility:

• IEC 60664-1:2020: Specifies the principles of insulation coordination for equipment within low-voltage systems and is the authoritative basis for determining withstand voltage values.
• IEC 60060-1:2010: Defines basic terms, measurement methods, and environmental correction factors for high-voltage test technology.
• GB/T 1408.1-2016: Specifies the test specification for the electrical strength of insulating materials at power frequency.
• GB/T 311.1-2012: In-depth discussion of insulation coordination principles for high-voltage power transmission and transformation equipment.
• GB/T 16927.1-2011: General definitions and common requirements for high-voltage test technology.

5. Engineering Implementation of LISUN HIPOT Series Withstand Voltage Testing System

LISUN’s HIPOT series power frequency withstand voltage test equipment achieves full coverage from laboratory level to industrial field level through in-depth optimization of autotransformer regulation technology and cascade connection technology.

5.1 Core Model: Technical Parameter Analysis of HIPOT10-100KV

As the main model of this series, HIPOT10-100KV can output up to 100kV AC high voltage and 140kV DC high voltage through a precisely designed test transformer.

LISUN HIPOT Series Main Specifications Comparison Table:

Model	Capacity (kVA)	Output Voltage (kV) AC/DC	Output Current (mA) AC/DC	Rated Input Voltage (V)	Rated Input Current (A)
HIPOT2-10KV	2	10 / N/A	200 / N/A	200	10
HIPOT5-50KV	5	50 / 70	100 / 15	200	25
HIPOT10-100KV	10	100 / 140	100 / 50	200	50
HIPOT50-100KV	50	100 / 140	500 / 100	380	132
HIPOT100-100KV	100	100 / 140	1000 / 100	380	250
HIPOT50-150KV	50	150 / 210	333 / 100	380	132
HIPOT100-150KV	100	150 / 210	667 / 100	380	263

5.2 Precise Regulation: Autotransformer Control Mechanism

LISUN equipment smoothly changes the input voltage of the test transformer by manually or automatically adjusting the autotransformer. This regulation method avoids the high-frequency harmonic interference caused by electronic voltage regulation, ensuring the output waveform is a pure power frequency sine wave, thereby guaranteeing the objectivity of test results. Operators can read experimental data in real time and intuitively through the built-in high-voltage side voltmeter and low-voltage side ammeter.

5.3 Scalability: Cascade Connection Technology

This series of products has a core technical advantage—200V cascade tap. Through cascade technology, two or three units can be connected in series. For example, cascading two 100kV units can form an ultra-high voltage output of AC 200kV; cascading three units can even reach AC 300kV. This flexible configuration greatly reduces the initial cost for enterprises to purchase large ultra-high voltage equipment and improves equipment reuse rate.

6. Advanced Protection and Safety Design

High-voltage testing is a high-risk operation. LISUN HIPOT series equipment adopts multiple redundant protection measures in its design:

• Built-in Overcurrent Protection Circuit: When the leakage current of the tested sample exceeds the preset limit, or a surge current is generated at the moment of breakdown, the system can automatically cut off the power in milliseconds.
• Visualized Reading System: High-precision voltmeters and ammeters are used to ensure that experimental data is not only “measurable” but also “intuitively visible,” greatly reducing human misjudgment caused by reading errors.
• Compact and Portable Design: Despite being able to output ultra-high voltage, LISUN equipment still maintains a compact structural design for easy movement between laboratories and production sites.

7. In-depth Exploration of Typical Application Scenarios

7.1 Withstand Voltage Testing of High-Voltage Motors

Due to complex windings and harsh operating environments, high-voltage motors have extremely high insulation strength requirements. LISUN can extract 5-15kV medium voltage taps from the high-voltage windings according to user needs, specifically for power frequency withstand voltage tests of motor stator windings to prevent partial discharge of the insulation layer under high voltage.

7.2 Dielectric Strength Research of Insulating Materials

Scientific research institutions use HIPOT series equipment to conduct destructive tests on new composite materials. By continuously adjusting the boosting voltage, the critical voltage value at the moment of material breakdown is recorded, providing basic data support for insulation design.

8. Conclusion

As an indispensable part of electrical product development and production, withstand voltage testing is essentially an in-depth exploration of product safety boundaries. For every quality control engineer, a deep understanding of  What is a hipot test used for? Not only helps to correctly implement test standards but also guides product structure optimization through test feedback.

LISUN HIPOT series high-voltage withstand voltage test equipment, with its excellent cascade expansion capability, strict standard compliance, and multiple safety protection mechanisms, provides global customers with reliable, efficient, and safe insulation evaluation solutions. In the future wave of electrification, LISUN will continue to be committed to improving high-voltage detection accuracy, helping the industry cross the safety red line.

Tags：HIPOT10-100KV