Electrical Engineering Power Systems

𝗠𝗮𝗴𝗻𝗶𝗳𝗶𝗰𝗶𝗲𝗻𝘁 𝗼𝘃𝗲𝗿𝘃𝗶𝗲𝘄 𝗼𝗳 𝗮𝗻 𝗲𝗹𝗲𝗰𝘁𝗿𝗶𝗰𝗮𝗹 𝘀𝘂𝗯𝘀𝘁𝗮𝘁𝗶𝗼𝗻 Substations are used at the generation, transmission, and distribution levels. Generators (at various power plants) generally produce electricity at lower voltages. However, these lower voltages are not efficient for long-distance transmission primarily due to technical losses (such as power loss (I^2*R) or voltage drops). This is because the current is higher at a lower voltage for the same amount of power transmitted. This contributes to huge losses (I^2*R), where "I" is the load current and "R" is the line's resistance. A transmission substation is used to step up the generation voltage for long-distance delivery to reduce losses. Most power generation facilities are located far from customers (homes, businesses, and commercial or industrial electricity consumers). A transmission line length is considered: ✅ Short if it's less than or equal to 𝟱𝟬 𝗺𝗶𝗹𝗲𝘀 (𝗼𝗿 𝟴𝟬 𝗸𝗺).  ✅ Medium if it's greater than 𝟱𝟬 𝗺𝗶𝗹𝗲𝘀 (𝟴𝟬 𝗸𝗺) but less than or equal to 𝟭𝟱𝟬 𝗺𝗶𝗹𝗲𝘀 (𝟮𝟰𝟭 𝗸𝗺) ✅ Long if it's greater than 𝟭𝟱𝟬 𝗺𝗶𝗹𝗲𝘀 (𝟮𝟰𝟭 𝗸𝗺) The distribution substation takes the power from a transmission or sub-transmission substation and further steps down the voltages for distribution. For instance, a solar PV power plant is a generator. An inverter(s) is/are needed to convert the DC power from the solar panels to AC power before injecting it into a distribution or transmission network. Let's assume the expected power to be delivered is 2 MVA, and we have one central inverter at 600 V. The load current (I) at 600 V will be (𝟮 𝘅 𝟭𝟬^𝟲)/(𝟭.𝟳𝟯𝟮*𝟲𝟬𝟬) = 𝟭𝟵𝟮𝟱 𝗔. For simplicity, let's assume a conductor resistance of 0.5 ohms (keep constant) Power loss = 𝟭𝟵𝟮𝟱*𝟭𝟵𝟮𝟱*𝟬.𝟱 = 𝟭,𝟴𝟱𝟮,𝟴𝟭𝟮 𝗪 A load current of 1925 A is large, so we must buy large conductors and associated support systems to transport the 2 MVA apparent power. The technical losses and voltage drops at this current are significant and uneconomical. A transformer is used to transform the 600 V to say 34,500 V, and the current at such medium voltage will be: (𝟮 𝘅 𝟭𝟬^𝟲)/(𝟭.𝟳𝟯𝟮*𝟯𝟰,𝟱𝟬𝟬) = 𝟯𝟯 𝗔 and power loss 𝟯𝟯*𝟯𝟯*𝟬.𝟱 = 𝟱𝟰𝟱 𝗪 Same power, but now, we have a smaller load current to evacuate through a distance. For long distances and larger power, it's even more economical to step up the 34,500 V to a transmission level, say 115,000 V. At 115,000 V, the transferred current is further reduced to: (𝟮 𝘅 𝟭𝟬^𝟲)/(𝟭.𝟳𝟯𝟮*𝟭𝟭𝟱,𝟬𝟬𝟬) = 𝟭𝟬 𝗔.  and power loss is 𝟭𝟬*𝟭𝟬*𝟬.𝟱 = 𝟱𝟬 𝗪 These assumptions give a better perspective on the discussion. But remember that an increase in voltage will require you to consider factors such as increasing the cost of equipment insulation. A lot happens between these systems, so it can't be explained in this limited space. This is just an overview. 📹 Surdu Alexandru Andrei

For the first time, coal now provides less than half of China’s electricity. Coal supplied 49.7% of generation in the first half of 2026, down from nearly 80% at its 2011 peak. Renewables now provide more than 40%, with wind and solar alone generating nearly a quarter. For rough context, coal supplied around 50% of Poland's electricity in 2025, compared to ~70% in India and ~80% in South Africa. This is a significant change for a country that still consumes more coal than the rest of the world combined. But a falling share does not necessarily mean falling coal-fired generation. China's electricity demand has been growing so fast that coal generation has continued rising even as its share declined. Coal-fired generation reached a record in 2024 and then fell 1.6% in 2025 – its first annual decline in a decade. But looks set to rise again this year amid strong demand growth, unusually weak wind conditions and reduced gas generation. The next challenge for China is increasingly about integration: ✅ China already has enormous volumes of wind and solar, but grid congestion and curtailment mean not all of it can be used. ✅ Investment is therefore shifting towards transmission and storage, up 14% and 74% respectively in the first half of this year. ✅ Coal plants themselves need to operate more flexibly. Long-term generation contracts and other market arrangements can still give coal output priority even when renewable electricity is available. China’s renewable buildout has already pushed coal from almost 80% of electricity to less than 50%. The challenge is increasingly shifting from simply building clean generation to integrating it effectively into the power system.

🔧 Why C Still Reigns Supreme in the World of Systems and Embedded Development Despite the flood of modern programming languages, C is not going anywhere and for very good reasons. If you're an aspiring embedded systems engineer, systems programmer, compiler developer, or even working in IoT, automotive, aerospace, medical devices, robotics, OS kernels, or performance-critical AI systems—you need to know C. Not just surface-level, but deep—pointer-arithmetic, memory models, linker behavior, and beyond. 💡 Why Is C Still So Important? ✅ Foundational to Modern Software C forms the core of modern operating systems, device drivers, microcontroller firmware, networking stacks, and more. Linux, Windows kernel components, embedded RTOSs, and most bootloaders are all written in C. ✅ Portability + Performance With its ability to compile directly to machine-level instructions and fine-grained control over memory and CPU usage, C enables highly efficient and deterministic code—crucial in embedded and real-time systems. ✅ Hardware-Level Control C gives you direct access to registers, memory addresses, and low-level operations. That’s why ARM Cortex-M, AVR, STM32, PIC, and even bare-metal RISC-V systems are taught and programmed in C. ✅ Toolchain Ecosystem Toolchains like GCC, IAR, Keil, Clang, and GHS are optimized for C. Most debugging tools, static analyzers, and safety certification tools are designed with C in mind—especially in MISRA, AUTOSAR, ISO 26262, and DO-178C compliant industries. ✅ Ubiquity in Industry Interviews Whether it's NXP, Infineon, Qualcomm, Intel, or Bosch—C questions dominate embedded interviews. From bit manipulation to memory maps to ISRs, you can’t escape it. 📍 Where Is C Used? Microcontrollers & Bare Metal Programming (e.g., STM32, AVR, MSP430) Kernel and OS Development (Linux Kernel, Windows NT) Drivers and Firmware (USB, UART, I2C, SPI, CAN) IoT Platforms (Contiki, RIOT OS, Zephyr) Automotive Software (AUTOSAR BSW modules) Medical and Aerospace Systems (Safety-critical environments) Compiler and Interpreter Backends Network Stack and Protocol Implementation 🔍 How Much C Should You Know? ➡️ Enough to design your own OS kernel modules and bootloaders. But practically, you should master: 🧠 Pointers and Memory Management Pointer arithmetic, const correctness, double/triple pointers Dynamic/static memory regions (stack/heap/data/bss) 🛠️ Bitwise Operations & Memory Mapping Efficient register-level manipulation (critical for peripheral drivers) 🔁 Control Flow, Optimization, and Inlining Loop unrolling, reducing function call overhead 📎 Linkers, Compilers, and Makefiles Understand .data, .bss, heap, and stack behavior Learn gcc, ld, nm, objdump and make 🧪 Unit Testing and Safety Coding Standards CppUTest and MISRA C compliance 🧬 Interrupts and ISRs Handling concurrency, atomic operations, volatile, and memory barriers 💻 Toolchain Knowledge Cross-compilation, flashing, and JTAG/SWD debugging #CProgramming

This week alone, we’ve replaced 4 transformers across different sites—each less than 5 years old. We’ve also rebuilt 2 switchboards that suffered flashovers, and we’ve already got the orders in to completely renew them. All of them were tied to solar sites. All of them were avoidable. Let’s stop pretending this isn’t happening. Too many of these substations were built as an afterthought—thrown in cheap to hit grid connection deadlines and satisfy investors chasing returns, not long-term reliability. We’re seeing: Switchgear that’s corroded beyond repair in under 60 months Inverters dumping harmonics back onto the network with no mitigation Poorly specced protection schemes that offer no selectivity or grading Transformers undersized, under-ventilated, and overstressed from day one No provision for future battery integration or reactive power compensation This isn’t about bad luck. It’s about bad design. And it’s happening across the country. Some of these sites will never make it to year 10 without major intervention. Many will fail long before their PPA matures. And every time it’s the same story: “we didn’t think it needed to be that robust,” “we had a tight budget,” “we assumed it would last.” You don’t build a resilient energy future with assumptions. At Johnson & Phillips, we’ve built our reputation on fixing what others cut corners on. But make no mistake—our goal isn’t just to repair. It’s to raise the standard. Power distribution infrastructure matters. Substations are not just connection points—they’re the backbone of performance, safety, and scalability. If you build them like an afterthought, they will fail. And they are failing. This isn’t a warning. It’s already happening. If you’re operating, investing in, or building solar and storage sites—make your substation a priority. The quality of your entire system depends on it.

Too small to believe… Texas Instruments just released a microcontroller so small you could lose it in your pocket. The MSPM0C1104 is only 1.38 mm², smaller than a grain of rice, but still acts as a tiny computer. It has a 32-bit processor running at 24 MHz, with 1KB of memory and 16KB of storage. It can even sense things like temperature or movement. Power use is minimal, running on just 87μA per MHz and dropping to 5μA in standby. This makes it ideal for tiny devices that need to last a long time on small batteries. It is also built to handle extreme conditions, working in temperatures from –40°C to 125°C. At 20 cents in bulk, this Texas Instruments microcontroller is designed for medical wearables, smart sensors, and other small electronics, like health monitors, industrial sensors, or smart tags that run for years on a coin cell battery. For comparison, the Raspberry Pi RP2040, used in many DIY projects, is more powerful but much larger. This TI chip is meant for cases where every millimeter and every bit of energy matters. On the other hand, devices this tiny are not easy to work with. Mounting them on a PCB risks getting very low yields. Think of a tiny BGA that has way less mass to support and mount. Another thing: passive components around it would be a lot larger, and would become the size drivers; What do you think, what would be a good application for these guys? Daily #electronics insights from Asia. Follow me, Keesjan, and subscribe to our newsletter here: https://zurl.co/EhYi3   #technology #innovation

#Understanding Electrical Power Transmission and Distribution Systems: Electricity generation, transmission, and distribution are the backbone of modern energy supply systems. #Stages of Power Transmission 1.The journey of electricity begins at power plants, where electricity is generated at low voltages — typically around 12 kilovolts (kV). While this voltage is sufficient for local distribution, it poses challenges for long-distance transmission due to energy losses that can occur. 2.Adjacent to the power plant are step-up transformers. They play a critical role in increasing the voltage from 12 kV to much higher levels, such as 400 kV. The reason for stepping up the voltage is simple: higher voltages improve the efficiency of long-distance electricity transmission, as they minimize the energy losses due to resistance in the wires. 3.Once transformed to higher voltages, electricity travels through high-voltage transmission lines, which are typically supported by tall towers. These robust lines can convey large amounts of electricity over great distances, connecting power plants to substations and major distribution nodes. 4.As electricity nears its destination, it reaches a substation equipped with step-down transformers. These transformers reduce the voltage from high levels, like 400 kV, down to 33 kV, making it safer and more practical for distribution within urban and suburban areas. 5.After undergoing further voltage reductions, electricity is distributed through smaller lines at voltages such as 240 V or 110 V. This final tier of the system serves homes, businesses, and other consumers, providing them with the electricity needed for daily operations. 6.Finally, the electricity reaches the end consumer, depicted in the diagram on the far right as a house utilizing electricity at the common residential voltage of 240 V. At this stage, electricity is ready for use in various applications, from lighting to powering appliances. ##TransmissionVoltagesandDistances A key factor in the efficiency of the electrical power transmission system lies in the voltage levels used for different transmission distances. The accompanying table below summarizes these voltage levels, illustrating their application based on distance.This table highlights how higher voltage levels are crucial for reducing energy losses over longer distances. Achieving efficient transmission is vital for maintaining the stability and reliability of the electrical grid. The systematic process of electricity generation, transformation, and distribution demonstrates the complexity and precision involved in supplying power to consumers. By elevating the voltage for long-distance transmission and subsequently lowering it for safe consumption, the electrical power transmission system ensures that energy travels efficiently from its source to our homes and businesses...

Direct electrification for the win Electric vehicles are WAY more efficient than diesel or gasoline cars i.e. that they convert much more of the input energy to the wheels (https://lnkd.in/e7mrVfZK). The Sankey diagram below, extracted from an article recently published in Joule, shows the different losses occurring between the electricity generator (renewables are assumed here) and the wheels. In this calculation, the full cycle efficiency is about 65%. The paper also looks at the cases of a hydrogen fuel cell and e-gasoline (produced from CO2) car. In both cases, the hydrogen is assumed to be produced through electrolysis of water. A battery EV car is respectively about 3 and 6 times more efficient than those 2 alternatives. For the former case this is in large part because of the energy cost of electrolysis electricity generation through the fuel cell (as well as the transport and storage of hydrogen). In the latter case one adds the energy cost of making CO2 react with hydrogen to produce fuels. The paper also studies the cases of trucks (batteries for the win !), and trains and planes. For planes, efficiency is of course not the main factor- weight (and so energy density) matters quite a lot. Source of the graph: https://lnkd.in/e9-g_Yrw #electrictransportation #electricvehicles #energyefficiency #transport

Low power factor is a problem for both utilities and consumers. 1. Inefficient Use of System Capacity: · The utility's generators, transformers, wires, and switches must be large enough to handle the Apparent Power (kVA), not just the Real Power (kW). · If your power factor is low, you are using up the system's capacity with non-working (reactive) power. This is like a delivery truck being half-full of empty boxes—it's a waste of space and resources. 2. Increased Energy Losses: · The current flowing through the wires is higher for a given amount of real power when the power factor is low. Higher current means higher losses due to the resistance of the wires (I²R losses), leading to wasted energy and voltage drops. #Electrical #Engineering #Power ⚡🧑🔧

Understanding Power Quality: The Key to Reliable Energy Systems 🔌 What is Power Quality? Power quality is essential for maintaining the efficiency, reliability, and longevity of electrical systems. It encompasses all aspects of voltage, current, and frequency that impact the performance of electrical devices. Poor power quality can lead to higher energy costs, equipment malfunction, and operational disruptions, making it critical to identify and address these issues effectively. 📊 Key Aspects of Power Quality and Their Impact: 1️⃣ Under/Over Voltage: Description: Deviations from the nominal voltage levels. Impact: Can cause overheating, insulation failure, and premature equipment aging. 2️⃣ Flickers: Description: Rapid and repeated voltage fluctuations. Impact: Results in visible disturbances like flickering lights, which can affect sensitive devices and disrupt operations. 3️⃣ Swells: Description: Short-term voltage increases above the nominal level. Impact: Leads to insulation breakdown in devices and over-stressing of equipment. 4️⃣ Unbalance: Description: Unequal voltage or current magnitudes in a three-phase system. Impact: Causes overheating of motors and transformers, leading to reduced efficiency. 5️⃣ Frequency Deviation: Description: A shift from the nominal system frequency (e.g., 50 Hz or 60 Hz). Impact: Affects synchronous machines, generators, and grid stability. 6️⃣ Harmonics: Description: Distortion in the electrical waveform due to non-linear loads. Impact: Leads to equipment overheating, higher losses, and potential failure of sensitive systems. 7️⃣ Sags: Description: Short-term voltage drops below nominal levels. Impact: Can cause machinery to stop, disrupt sensitive processes, and lead to production downtime. 8️⃣ Transients: Description: Sudden and temporary spikes or dips in voltage. Impact: Damages electronic devices and leads to malfunctioning of sensitive equipment. 9️⃣ Interruptions: Description: Complete loss of power for a duration. Impact: Halts industrial and commercial processes, causing significant operational and financial losses. 💡 Why Power Quality Matters? Improved Equipment Lifespan: Reduces wear and tear caused by voltage and frequency fluctuations. Enhanced System Efficiency: Minimizes energy losses, saving costs in the long run. Operational Continuity: Prevents unexpected downtimes and enhances productivity. Sustainability: Optimized power systems reduce energy wastage and environmental impact. 🔧 How to Improve Power Quality? Install voltage regulators to stabilize under/over voltage. Use active filters to mitigate harmonics. Employ uninterruptible power supply (UPS) systems to address interruptions. Implement real-time monitoring for early detection and prevention of power quality issues. 🔗 Let’s Discuss! What power quality challenges have you faced in your system https://lnkd.in/gmvxm2UZ

🔋 UPS Battery Backup Time ⚙️ The battery backup time of an Uninterruptible Power Supply (UPS) system is a critical design parameter that defines the duration for which essential loads remain powered during a utility supply failure. Accurate estimation of this time is indispensable for ensuring system reliability, operational continuity, and equipment protection in critical infrastructure such as data centers, healthcare facilities, industrial plants, and control stations. Practical design requires deeper analysis of several influencing factors: C-Rate Dependency: Battery discharge capacity varies with the rate of discharge. At higher rates, available capacity reduces significantly. Peukert’s Law applies to lead-acid batteries and must be factored into time calculations. Depth of Discharge (DoD): The permissible DoD varies by battery type. Deeper discharges reduce available cycle life, impacting long-term reliability. Temperature Influence: Battery performance deteriorates at temperatures below the standard 25°C reference. Capacity derates typically range from 0.5% to 1% per °C below nominal. Aging and Derating: Over operational cycles, battery capacity degrades due to chemical wear mechanisms. Incorporating an appropriate design margin (typically 10–25%) ensures backup time is maintained over the battery's service life. Discharge Profiles and Internal Resistance: Backup time is influenced by battery internal resistance and its discharge voltage curve, which must be referenced from manufacturer datasheets for accuracy. System Configuration: Series and parallel arrangements determine total system voltage and ampere-hour capacity. Proper configuration is necessary for voltage matching, redundancy, and reliability. UPS Efficiency and Load Characteristics: The actual power drawn from the battery depends on the inverter's efficiency and the power factor of the connected load. Real (kW) power must be used in sizing, not apparent (kVA) power alone. ⚠️ Importance: ✅ Operational Continuity: In applications where even milliseconds of power loss are unacceptable, accurate battery sizing ensures uninterrupted function. ✅ System Protection: Prevents abrupt shutdowns of sensitive equipment, reducing risks of data loss, hardware damage, or process disruption. ✅ Compliance and Standards: Regulatory guidelines and design standards (e.g., IEEE Std 485) require proper backup time estimation as part of system validation. ✅ Cost Optimization: Oversizing leads to unnecessary capital expenditure, while under sizing risks critical downtime. A precise theoretical approach balances both. #PowerElectronics #UPSSystems #BatteryTheory #ElectricalEngineering #EnergyStorage #IEEE485 #BackupTime #CriticalInfrastructure #PowerSystemsEngineering