Zakaria El Intissar

I’m a power automation engineer passionate about innovation in the energy sector. I specialize in control systems and SCADA solutions for electrical substations. With strong hands-on experience, I design, implement, and optimize these critical technologies to keep energy infrastructures running reliably. I’ve also worked on renewable-energy projects, where I helped develop new solutions that support a sustainable energy transition.

Author Archives: Zakaria El Intissar

IEC 61850-9-2 Sampled Values: Complete Guide to Digital Substation Communication

The world of electrical power systems is changing rapidly. As demand grows, renewable energy expands, and reliability expectations increase, the traditional substation—filled with copper wiring, electromechanical devices, and point-to-point analog signals—can no longer meet modern requirements. Digital substations are changing the game. Instead of relying on tons of physical wiring, they use fast communication networks to move information… Read More »

Performing Power Factor Test on Dry-Type Transformer During Commissioning

During transformer commissioning, one of the most important diagnostic procedures is the power factor test. This test assesses the dielectric losses in the transformer’s insulation system, which are directly related to insulation quality and integrity. For dry-type transformers, the power factor test helps identify potential insulation deterioration due to moisture, contamination, carbonization, or other degradation mechanisms that may… Read More »

Electrical Testing of Dry-Type Transformers

Dry-type transformers are integral to the electrical infrastructure of industrial, commercial, and institutional facilities. Because these transformers power critical systems, regular electrical testing and maintenance are essential to ensure safety, reliability, and performance. This article summarizes recommended electrical tests and maintenance practices for dry-type transformers rated 500 kVA and above, based on ANSI/NETA MTS-2019 (Maintenance Testing Specifications) and… Read More »

Distance Protection Schemes: Working Principles, Types, and Comparison

Distance protection schemes play a vital role in ensuring reliable and speedy fault clearance on transmission lines. The fundamental idea behind distance protection is to measure the impedance between the relay location and the fault point, enabling the relay to detect faults within set zones. Conventional time-stepped distance protection, for instance, sets an instantaneous Zone 1 reach to about… Read More »

Virtual Protection Relays: Complete Guide to IEC 61850 Digital Protection

The digitalization of substations is transforming the way power systems are protected and controlled. Virtual Protection Relays (VPRs) are a major step in this evolution. Instead of using dedicated hardware devices, protection functions now run as software on virtual machines or high-performance computing platforms. This shift is made possible by standards such as IEC 61850-9-2 LE and devices… Read More »

What Is an Interposing Relay? Function, Uses & Benefits Explained

An interposing relay (sometimes called an interface relay or isolation relay) is essentially a relay used to interface two circuits that have different electrical characteristics (e.g. different voltages, current levels, or common references). It “interposes” itself between a control circuit (e.g. PLC, sensor output) and a load or another circuit that may not be directly compatible. Key roles… Read More »

Understanding Magnetising Inrush in Transformers

Magnetising inrush is a transient electrical phenomenon that primarily occurs when a power transformer is energized. It is not indicative of a fault but rather a normal response of the transformer’s magnetic core to sudden application of voltage. However, it poses significant challenges for transformer protection systems, which must distinguish this temporary surge from actual faults to avoid… Read More »

Understanding MV Switchboard Power Supply Modes

Medium Voltage (MV) switchboards are critical components in electrical distribution networks, responsible for controlling, protecting, and isolating electrical equipment. The power supply modes for these switchboards vary based on the required level of redundancy, reliability, and operational flexibility. These modes determine how supply sources connect to the busbars and feeders, ensuring continuity of power while minimizing downtime during… Read More »

Polarization Index (PI) and DAR Tests: Assessing Electrical Insulation Quality

Insulating materials are fundamental to the safe and efficient operation of electrical systems, serving to separate conductive parts from non-conductive ones and prevent unintended current flow. In high-voltage equipment such as motors, generators, transformers, and cables, insulation integrity directly impacts reliability, with studies estimating that up to 98% of electrical failures originate from insulation degradation due to factors… Read More »

What are the Differences Between Substation and Switchyard?

In electrical power systems, substations and switchyards form critical nodes that ensure the efficient, safe, and reliable transfer of electricity from generation sources to consumers. While often discussed interchangeably in casual contexts, they exhibit distinct characteristics based on their functions, equipment, and placements within the grid. This comprehensive overview draws from engineering principles and industry practices to delineate… Read More »