Introduction

An Impulse Voltage Generator is a crucial piece of equipment used in high-voltage engineering for testing the insulation strength of electrical apparatuses, such as transformers, circuit breakers, insulators, and cables. It simulates lightning strikes or switching surges by generating high-voltage impulses to test how well electrical equipment can withstand transient overvoltages.

 

 

What is an Impulse Voltage Generator?

An Impulse Voltage Generator (IVG) produces short-duration, high-voltage pulses—typically 1.2/50 µs lightning impulses or 250/2500 µs switching impulses. These pulses are used to assess whether a piece of high-voltage equipment can endure the types of voltage spikes it might experience during real-world operation. These generators are designed to deliver controlled waveforms with high peak voltages ranging from tens of kilovolts (kV) to several megavolts (MV).

 

 

Principle of Operation

The basic operation of an impulse voltage generator involves charging capacitors in parallel and then discharging them in series through a wave-shaping network that includes resistors and inductors. This rapid discharge produces a high-voltage impulse. The waveform can be shaped into either lightning impulses or switching impulses depending on the network configuration.

 

 

Key Components

 

• Charging Unit: Charges the capacitors using a DC high-voltage power supply.


• Capacitor Bank: Stores the energy required for the impulse.


• Discharge Switch (Triggering Gap): Initiates the discharge at the required voltage level.


• Wave-Shaping Network: Comprises resistors and inductors to control the rise and fall time of the impulse.


• Measuring Equipment: Includes voltage dividers, oscilloscopes, and peak voltmeters to analyze the waveform.

 

 

 

Types of Impulse Voltages

 

1. Lightning Impulse: A 1.2/50 µs wave used to simulate natural lightning strikes. The first number represents the rise time and the second the fall time.


2. Switching Impulse: A longer duration impulse (e.g., 250/2500 µs) simulating overvoltages caused by switching operations in power systems.

 

 

 

Applications

Impulse Voltage Generators are used for:

 

• Type testing of power transformers and insulators


• Testing GIS (Gas Insulated Switchgear) and HV circuit breakers


• Research and development in high-voltage labs


• Testing cables and bushings

 

 

 

Advantages

 

• Accurately simulates real-world high-voltage surges


• Ensures safety and reliability of power equipment


• Customizable wave-shaping networks


• Useful for both academic and industrial testing

 

 

 

Safety Considerations

Impulse Voltage Testing involves extremely high voltages and fast discharge rates. Proper shielding, grounding, remote operation, and interlocking systems are necessary to ensure safety for both personnel and equipment. Visit our website https://www.uhvtest.com/ for more details.

 

 

Conclusion

An Impulse Voltage Generator plays a vital role in the quality assurance and safety of electrical equipment in power systems. By simulating extreme overvoltage conditions like lightning and switching surges, it enables engineers to detect insulation weaknesses before failures occur in real environments. Whether in a manufacturing plant or a high-voltage test lab, the IVG remains an indispensable tool for electrical testing and reliability assurance.