What are the causes of voltage peaks

Power supply risk factor - these power problems could be your undoing

In today's electrified and connected digital world, electricity problems can have far-reaching consequences. If, for example, technical devices in hospitals no longer work as a result of a power failure, this can theoretically cost lives. In production, production lines can get out of control and pose a threat to plants, employees and the environment. An interrupted power supply can also have fatal consequences for companies and authorities. In this case, no life is threatened, but data loss and damage to the hardware can cause enormous economic damage. The first step in arming yourself against electricity problems is to address their causes. The Institute of Electrical and Electronics Engineers (IEEE) defines the following types of power disturbances:


Voltage surges

Voltage surges are particularly dangerous. They are divided into pulse-like voltage surges and vibration-like voltage surges.

Impulse-like voltage surges

Impulse-like voltage surges are sudden events that result in an increase in voltage and / or current in both a positive and a negative direction. Such events include Lightning strikes, poor grounding, switching from Induction load as ESE (electrostatic discharge). Lightning strikes are one of the most dangerous causes of impulsive voltage surges. The elimination of potential ESDs and the use of surge protection devices (Transient Voltage Surce Suppressors, TVSS or Surge Protective Devices, SPD) are among the most important protective measures.

Vibratory voltage surges

Vibration-like voltage surges result from Rise and fall of the current signal in very rapid alternation. For example, they can occur when Electric motors or capacitor banks switched off become. A zero-crossing circuit is often used to avoid voltage surges in connection with capacitor circuits. This circuit solves the problem by continuously monitoring the sine wave of the current signal.


Interruptions describe the complete loss of supply voltage. They can be categorized into short, temporary or persistent interruptions. The causes are diverse and can include the following events: lightning strike, Animals (gnawed cables), falling trees on lines, Vehicle accidents and extreme weather conditions. An interrupted power supply can also be observed in private households if the power suddenly fails for a short time. This can also damage electrical devices. Both personal and business data can be lost this way. To prevent power interruptions, UPSs (uninterruptible power supply) are recommended. They have a powerful battery and in this context function as an emergency power generator.

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Voltage drop / undervoltage

A Voltage drop occurs when the AC mains voltage is reduced for the duration of a half-cycle of up to one minute at a given frequency. Voltage dips are often caused by system errors and connected loads with high starting currents (e.g. the commissioning of a large air conditioning system or electric motors). Switching on such devices will most likely cause the voltage to drop.
Undervoltage can overheat electric motors and cause computer power supplies to fail. The
The approach to solving voltage drops and undervoltage is also called UPS in this case. This is used to regulate voltages through an inverter.

Voltage peaks / overvoltage

The opposite of a voltage dip is the voltage rise. The AC mains voltage increases for the duration of a half oscillation of up to one minute. They are triggered by sudden large load reduction as well as single phase faults in a three phase system. This can result in data errors, flickering lighting, semiconductor damage and deterioration in electrical contacts.
An overvoltage is a constant voltage increase that exceeds the tolerance range of the nominal voltage of the respective electrical device. The main causes of overvoltages are poor power regulation by energy providers and power outages in the neighboring network, but also a sudden drop in load due to application errors or a drop in consumption during the night. This can result in damage to insulation cables, semiconductor components and temporary malfunctions or failures of electronic circuits.

Waveform distortion

There are five different types of waveform distortion: DC skew, harmonics, intermediate waves, brief voltage dips, and noise.

DC offset

If Direct current an alternating current system traversed, can devices unwanted electricity are fed. The DC offset can cause the affected equipment to overheat and general electronic load instability.


In the case of harmonics, the frequency is above the 50 Hertz fundamental frequency. They can be triggered by equipment such as Transformers, fluorescent lamps, rectifiers. Harmonics result in undesirable heating, a shortening of the service life, functional impairment and the destruction of devices.

Brief voltage dips

Devices such as variable speed drives, lighting dimmers or arc welding devices can trigger voltage drops. These periodic (impulse) voltage disturbances can cause brief voltage dips, system stops, data loss and data transmission problems.

Intermediate vibrations

Control converters that control large machines such as linear motors in rolling mills, cement works and mining machines convert the supply voltage into an alternating current voltage. This can be either higher or lower than the supply voltage, which can cause problems such as heat generation or transmission errors.


In the case of noise, the current flow is superimposed by undesired voltages and power supply. It can be caused, among other things, by electronic devices, control circuits, arc welding devices, switched-mode power supplies, or wireless transmitters. Even poorly grounded locations can make power systems susceptible to noise. The noise can lead to data errors, malfunctions, long-term component failure, hard drive errors and distorted video images.

Voltage fluctuations

“Voltage fluctuations in the power grid and brief interruptions in supply are a well-known phenomenon. Modern production systems with highly sensitive electronics should be prepared for this, ”said Environment and Energy Minister Franz Untersteller. A symptom of voltage fluctuations can be, for example, the flickering of incandescent lamps. Problem-solving approaches can include removing the interference load, relocating sensitive devices or installing line regulators or UPSs.

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Frequency fluctuations

An error of this type is also known as a frequency deviation. Harmonic harmonics can also be a disruptive factor. These distortions are caused, for example, by non-linear loads such as those generated by fluorescent tubes. Depending on which type of error occurs most frequently or is to be expected, a special UPS can be the perfect solution. In addition, a UPS must be tailored to the existing infrastructure.

Take preventive measures

Anyone who knows the different types of power disruptions can better assess the dangers and protect themselves against expensive failures in highly sensitive systems. An efficient way to protect yourself against the power problems mentioned is an uninterruptible power supply (UPS for short). Learn more about the structure, functions, properties, types and numerous advantages of the uninterruptible power supply.