What is Voltage Protection Relays: Functions, Types, & Applications

With the rise of electrical appliances, the safety of electrical systems has become paramount, both in civil and factory use. A critical component of protecting these systems is the voltage protection relay. These devices are very useful in safeguarding electrical circuits against the damaging effects of over- or under-voltages. But first, let us learn what voltage protection relays are. What are their uses, kinds and categories? 

What is a Voltage Protection Relay?

A voltage protection relay is defined as electrical equipment that is employed for protecting an electrical system against over-voltages, under-voltages, or voltage unbalances. It continuously measures voltage levels within electrical systems, and if it recognises a voltage problem that might damage equipment, it prompts system disconnection or shutdown. Industrial and conventional application uses of voltage protection relays include residential electrical systems because managing the fluctuations in voltage is crucial to protect electrical equipment.

What is Protective Relay?

A protective relay is an instrument that senses abnormalities such as overload, fault, or voltage variation in the electrical circuit and takes proper action to protect the system. These protective relays are designed to operate with circuit breakers to disconnect the faulty section of a circuit and maintain the electrical system's stability and safety.

In other words, a voltage protection relay is a kind of protective relay mainly concerned with voltage protection problems. This means that all voltage protection relays are protective relays, though not all protective relays are involved with voltage alone.

Working Principle of Protective Relay

For one to fully appreciate its importance, it is necessary to understand the working principle of protective relay. Protective relays are meant to measure electrical disturbances, and once they are detected, specific countermeasures are initiated. They consist of three primary components:

• Sensing Element: This part ensures you know the system’s electrical parameters, such as voltage, current and frequency.
• Decision-Making Element: This component also determines when to sound an alarm when it detects an abnormality in the situation sensed by the sensor.
• Actuating Element: If the decision-making component finds a fault, the actuating element switches off the faulty circuit by opening a circuit breaker or any other protective gadget.

Real-time operation is found in the case of a voltage protection relay in which the device measures the voltage. If it senses a voltage fluctuation, it triggers a message for the circuit breaker to open the circuit, thus preventing the connected system from being damaged. 

Types of Protective Relays

Protective relays are divided into several categories based on their function, the type of technology used, and the parameters they provide protection. Below are some common types of protective relays:

• Electromechanical Relays: These are old-school ones that operate using magnetic fields. Although not very frequently used today, they are still present in some outdated electrical installations.
• Static Relays: This type of protection relay uses solid-state electronic components to perform the protection function. They are quicker forms of electromechanical relays and are preferred in this respect.
• Digital Relays: Digital relays are the most highly developed, equipped with microprocessors that enable them to receive, analyse, and respond to electrical signals. They are highly programmable, accurate, and reliable relays for any microprocessor or microcontroller.
• Overcurrent Relays: As the term suggests, these relays protect against overcurrent in the system.
• Voltage Protection Relays: These relays are designed to detect and reinforce suspicious voltage conditions.

Functions of Protective Relays

Protective relays are essential in ensuring the well-being and safety of electrical systems. Protective relays serve several purposes:

• Fault Detection: This equipment notices conditions that are indirect to the electrical system, such as fluctuations in the voltage level, short-circuiting and overloading.
• Circuit Isolation: A protective relay is used to identify a fault and then switch off a circuit breaker to prevent damage to the remaining system.
• System Monitoring: Protective relays always measure specific quantities (voltage, current, frequency, etc.) to confirm whether the system's process is standard or not.
• Preventive Maintenance: In some advanced relays, monitoring data is known, which can help anticipate problematic occurrences. In such cases, preventive measures are implemented so that relay costs are not increased due to breakdowns.

Application of Protective Relays

Protective relays are used in almost all areas, and electrical structures are strongly involved in operation. Some of the most common applications include:

• Industrial Plants: It is well known that protective relays are assigned in power and other industries, where large machines and intricate electrical systems are applied to protect from voltage or current abnormalities to avoid serious and costly damages.
• Power Grids: Protective relays in power transmission and distribution facilities help control voltage levels and guarantee a stable and safe electrical energy supply.
• Residential Buildings: Voltage protection relays, in particular, are widely used in households today to guard appliances and the wiring system from by-voltages.
• Renewable Energy Systems: Renewable energy systems such as solar and wind, which undergo voltage fluctuations due to environmental challenges, are mastered by the voltage protection analogy.
• Data Centers: In data centres where power protection is deemed crucial, by using voltage protection relays, users can provide suitable power to their delicate electronics.

Schneider Electric eShop: Your Trusted Source for Voltage Protection Relays

When choosing a voltage protection relay for your application, it is crucial to opt for reliable, high-quality products. Schneider Electric, a global leader in energy management and automation solutions, offers a range of cutting-edge voltage protection relays designed for residential and industrial applications. The Schneider Electric eShop provides an extensive selection of voltage protection relays and other essential electrical products, ensuring top-tier performance and safety.

Read Also -  Control Relays - How They Work & What They are For?

Conclusion

Voltage protection relay is indispensable in maintaining the safety and efficiency of electrical systems. These relays protect valuable equipment from damage by continuously monitoring voltage levels and disconnecting the system during voltage fluctuations. With various protective relays available, choosing the correct relay for your application is essential. For high-quality voltage protection relays, consider Schneider Electric’s reliable solutions, which are available at their eShop.

Frequently Asked Questions

Q1. What is a voltage protection relay, and why is it important?

Ans: A voltage protection relay is a device that monitors electrical systems for abnormal voltage levels and disconnects the system when these anomalies are detected. It is essential because it prevents damage to equipment and electrical infrastructure caused by over-voltage or under-voltage conditions.

Q2. What is the difference between a voltage protection relay and a protective relay?

Ans: A voltage protection relay is a type of protective relay specifically designed to monitor voltage levels and respond to voltage abnormalities. In contrast, a protective relay can monitor various parameters, including voltage, current, and frequency, and provide comprehensive protection for electrical systems.

Q3. What are the primary applications of voltage protection relays?

Ans: The primary application of voltage protection relays includes industrial plants, power grids, residential buildings, renewable energy systems, and data centres, where they safeguard electrical systems from voltage-related issues. You can explore the Schneider Electric eShop for high-quality, reliable relays for a wide range of voltage protection solutions.