Voltage Monitoring

What Is Voltage Monitoring in Public and Industrial Energy Grids and How Does It Work?

Definition of Voltage Monitoring

Voltage monitoring refers to the continuous monitoring of the voltage in electrical networks to ensure that it is within defined tolerance limits. The official definition according to the DIN VDE 0108-100 standard is: “Voltage monitoring is the continuous monitoring of the voltage in electrical networks in order to detect deviations from the specified limit values and to take appropriate protective measures.” According to the definition of the VDE standard, voltage monitoring serves to “guarantee the quality and stability of the power supply and ensure the protection of electrical devices and systems”. This monitoring is crucial for the safe and efficient operation of electrical systems.

Necessity of Voltage Monitoring

Voltage monitoring is necessary in both public and industrial energy grids to ensure their operational safety and efficiency. In public energy grids, grid monitoring ensures that households, public facilities and large consumers are reliably supplied with electricity. In industrial energy grids, especially for machines and systems, voltage monitoring is crucial for trouble-free and economical operation. Phase monitoring plays an important role here to ensure that all phases are loaded evenly and that no phase imbalances occur.

Risks and Disadvantages Without Voltage Monitoring

Without voltage monitoring, various risks and disadvantages can occur:

• Overloading of devices: Electric motors and other electrical devices can be overloaded by undervoltage, resulting in damage or premature wear.
• Destruction due to overvoltage: Devices can be damaged or destroyed by overvoltage, for example due to faulty regulation of generators in stand-alone operation.
• Interruptions during operation: A lack of voltage monitoring can lead to unplanned outages and interruptions, resulting in high costs and productivity losses, particularly in industrial processes.

Results and Recommendations for Action From the Analysis/Measurement

Analysing and measuring the voltage monitoring can provide various results:

• Normal voltage: No action required as the voltage is within the acceptable & standard-compliant limits.
• Undervoltage and overvoltage: In the event of undervoltage, measures such as load reduction or switching off non-critical loads can be recommended to temporarily stabilise the voltage. Measures against overvoltage can be the use of overvoltage protection devices or adaptation of generator controls. In the area of low voltage in the distribution grid, the »LVRSys® low voltage control system« offers a flexible solution for voltage stability problems and is used by customers worldwide as an economical and quickly available alternative to line extensions. Click here for more information.
• Phase imbalance: May indicate uneven load distribution and may require load redistribution or phase correction.

Difference Between Undervoltage Monitoring and Overvoltage Monitoring

Undervoltage monitoring refers to the detection of voltage fluctuations that are below the specified level. Overvoltage monitoring, on the other hand, detects voltage fluctuations that are above the specified level. Both serve the purpose of keeping the voltage within the standard-compliant voltage tolerance and thus ensuring security of supply for energy supply companies and their consumers. Continuous voltage monitoring with our permanently installed PQ grid analysers also offers energy supply companies and large consumers such as industrial companies the possibility of monitoring and recording the reference qualities or quality agreements on voltage quality between energy suppliers and customers and making them available for evaluation or storage. The modern and highly accurate power quality measuring devices from A. Eberle are certified as “Class A” measuring devices in accordance with the IEC 61000-4-30 Ed. 3 standard. This standard defines suitable measurement technology and measurement methods in order to create comparable and reproducible measurement results. Measurement data from Class A measuring devices is also referred to as “court-proof”, as they have very high measurement accuracy and EMC (electromagnetic compatibility) and only measure what actually takes place in the network.

Voltage Monitoring for Different Voltage Levels

• Voltage monitoring 12V: Is often used in control circuits and DC control circuits. It protects against undervoltage and overvoltage in order to protect sensitive electronics.
• Voltage monitoring 24V: Similar to 12V systems, but often used in industrial control and automation systems.
• Voltage monitoring 230V: Relevant for household appliances and single-phase industrial applications. Here, monitoring protects against voltage fluctuations in the public grid.
• Voltage monitoring 400V (3-phase): Important in three-phase industrial grids. Monitors all three phases in a three-phase network. This is crucial for recognising and correcting phase imbalances. Ensures that machines and systems can be operated stably and safely.

Adjustable Voltage Monitoring

Adjustable voltage monitoring makes it possible to flexibly adapt the monitoring limits to the specific requirements of the respective system. This is particularly useful in complex industrial environments where different devices and machines have different voltage requirements. Therefore, adjustable voltage monitoring offers the possibility to configure individual protection mechanisms for different applications and thus achieve higher reliability and efficiency of phase monitoring and grid monitoring.

Phase Monitoring

Phase monitoring involves monitoring the voltage and phase position in three-phase systems. This ensures that all phases are in balance and thus prevents damage caused by phase loss or imbalance. Effective 3-phase grid monitoring is crucial to ensure the stability and efficiency of complex industrial networks.

Grid Monitoring in Accordance With DIN VDE 0126-1-1

Grid monitoring in accordance with DIN VDE 0126-1-1 ensures that both public and industrial energy networks operate safely, reliably and efficiently by continuously monitoring the voltage and phase position and activating protective measures if necessary.

Voltage Monitoring in a Nutshell

Voltage monitoring is an essential part of the energy supply, both in public and industrial grids. It ensures the safe and efficient operation of devices and systems and protects against the risks and disadvantages of voltage deviations. Monitoring can be applied to different voltage levels and phases to ensure comprehensive grid monitoring. Compliance with the relevant standards, such as DIN VDE 0126-1-1, is of great importance to ensure the safety and reliability of the power supply.