Understanding Electrical Systems

We are almost certainly Sleepwalking into a System-Wide Blackout? Last Monday, the Iberian grid collapsed in 3.5 seconds. Not minutes—seconds. At 12:33, a disturbance in southwestern Spain quickly cascaded. France disconnected, renewables dropped off, and soon after, so did rotating generation. A total blackout engulfed Spain and Portugal. Why? Because 79% of their 28.4GW generation was solar and wind—sources that supply zero grid inertia. What is Inertia, and Why Should You Care? Inertia is the silent stabiliser of every electrical grid. Thermal generators—gas, coal, and nuclear—supply it through heavy spinning turbines. When something disturbs the grid, that kinetic energy resists sudden frequency swings, buying operators precious seconds to act. Renewables don’t provide that buffer. They disconnect immediately when frequency wobbles beyond limits. No resistance. No time to correct. Just… blackout. The UK Is Headed the Same Way • 66% of UK generation (as of this Tuesday) had no inertia—solar, wind, and DC imports. • Dinorwig, our backbone pumped-storage stabiliser, is offline for repairs with no return date. • We’re retiring our gas and nuclear base. • And we’re doing this while increasing asynchronous renewables. Let’s be clear: the UK grid has never suffered a total blackout. Not even in WWII. But how long can we keep that record? Grid Engineers: You’re Not Alone At Johnson & Phillips, we work on the front line of power quality and grid stability. We test. We analyse. We reinforce. Whether it’s inertia substitution, stabilisation through PFC systems, or consulting on resilient interconnection strategies—we’re here to help design and defend a resilient, responsive power system. What Now? Inertia used to be a given. Now it’s a luxury. As we race toward a renewable future, we can’t ignore the engineering truths: No inertia means no forgiveness. No Volume…. Let’s start making inertia part of every system design, every policy conversation, every operational plan. #PowerQuality | #GridStability | #EnergyTransition | #JohnsonAndPhillips | #InertiaMatters | #ElectricalResilience | #UKGrid | #Renewables

This image represents the “Duck Curve,” a common visualization of electricity system load over the course of a day, highlighting the challenges of integrating renewable energy into the grid. Here’s a detailed explanation: 1. System Load (Y-axis): The graph shows the electricity demand in megawatts (MW) over time. 2. Time of Day (X-axis): The curve spans a 24-hour period, starting at 6 AM and ending at 9 PM. 3. Historical and Forecasted Trends: • The colored solid lines represent actual system loads for different years (2020 to 2023). • The dashed lines show forecasts for 2024 and 2025. 4. Duck Shape: • The “belly” of the duck (midday dip) reflects low electricity demand during peak solar generation (12 PM–3 PM), as solar panels supply a significant portion of energy. • The “neck” (steep rise after 3 PM) highlights the rapid increase in demand when solar generation decreases and other sources must ramp up quickly to meet the evening demand. 5. Grid Stability Challenge: • The shaded area near the bottom indicates “potential for grid instability,” occurring during the lowest load times. This happens because traditional power plants might struggle to reduce their output quickly enough to accommodate the surge in solar power. 6. Key Observations: • The midday dip grows deeper over the years due to increased solar generation. • The evening ramp (neck) becomes steeper, emphasizing the need for flexible power sources (like battery storage or fast-ramping plants) to balance the grid. Conclusion: The Duck Curve illustrates the need for grid modernization, storage solutions, and demand-side management to handle the variability of renewable energy sources like solar power.

Me today dealing with some EMC issues… 🧙♂️🪄🐉 EMC might feel like black magic sometimes, but it’s not all spells and wand-waving. Here’s the checklist I worked through today to troubleshoot: 1️⃣ 𝗕𝗲 𝘄𝗮𝗿𝘆 𝗼𝗳 𝘄𝗶𝗿𝗶𝗻𝗴 𝗮𝗰𝘁𝗶𝗻𝗴 𝗹𝗶𝗸𝗲 𝗮𝗻 𝗮𝗻𝘁𝗲𝗻𝗻𝗮. Anything with wiring can pick up noise and radiate it—even cables that seem unrelated to your core system. If the cable isn’t critical, remove it and retest to isolate the problem. If you can’t remove it, try adding a ferrite ring to the cable as close to the board as possible On the PCB, ferrite beads or chokes can also help suppress noise if you’ve got space to add them. 2️⃣ 𝗦𝗹𝗼𝘄 𝗱𝗼𝘄𝗻 𝘆𝗼𝘂𝗿 𝗠𝗢𝗦𝗙𝗘𝗧 𝗴𝗮𝘁𝗲 𝗱𝗿𝗶𝘃𝗲 𝘀𝗶𝗴𝗻𝗮𝗹𝘀. This is one of the top culprits for EMI on motor drive boards. Increasing both the turn-on and turn-off resistors for your MOSFET gate drive slows the rise and fall times of the signal, which directly cuts down on emissions. 3️⃣ 𝗥𝗲𝗱𝘂𝗰𝗲 𝗣𝗪𝗠 𝗳𝗿𝗲𝗾𝘂𝗲𝗻𝗰𝗶𝗲𝘀. We had a 250kHz PWM signal driving a battery charger boost converter. The lab results weren’t happy, so we made some changes: - Dropped the frequency to 75kHz. - Increased the inductor value to match the new frequency. - Slowed down the MOSFET rise time (see point 2). This got us under the threshold—barely (around 2dB). We’ll reduce the charge current by about 15% to get a little more breathing room. 4️⃣ 𝗖𝗵𝗲𝗰𝗸 𝘆𝗼𝘂𝗿 𝗿𝗲𝘁𝘂𝗿𝗻 𝗽𝗮𝘁𝗵𝘀. High-current or high-frequency signals need clean return paths—no exceptions. In our case, we were stuck with a 2-layer PCB (budget constraints, of course), and the ground return path for the low-side MOSFET gate drive signal ended up being pretty big. I spotted a way to reduce the loop area by adding a via. We drilled a quick hole in the board and connected it with a wire. Not pretty, but it worked! The layout will need redoing, but this hack let us verify the solution at the test lab. If you haven’t already, check out 𝗔 𝗛𝗮𝗻𝗱𝗯𝗼𝗼𝗸 𝗼𝗳 𝗕𝗹𝗮𝗰𝗸 𝗠𝗮𝗴𝗶𝗰 𝗯𝘆 𝗛𝗼𝘄𝗮𝗿𝗱 𝗝𝗼𝗵𝗻𝘀𝗼𝗻. It’s the go-to resource for high speed digital electronics theory, and will let you analyse EMC issues way more effectively. What are your favorite resources for EMC troubleshooting? Drop them below—I’m always on the lookout for more tools/knowledge to add to my wizarding arsenal! 🪄 ------------- 🔔 Follow Ryan Dunwoody for more hardware chat 🚀 ♻️ Repost if you're an EMC wizard (or would like to be) 🧙♂️

🔌 Relay vs Contactor – What’s the Real Difference? In the electrical industry – especially in elevator systems, motor control panels, and automation setups – both relays and contactors play important roles. But they’re not the same! Let’s break down the key differences, uses, and how they work👇 --- 🔹 What is a Relay? A relay is an electrical switch that uses a low-power signal to control another circuit. It’s commonly used in logic circuits, signal switching, and control panels. ⚙️ Features of Relay: Controls small currents (typically less than 10A) Works on low voltages like 5V, 12V, 24V DC Used in control and signaling circuits Suitable for logic-level operations and automated triggers 🔄 How It Works: A relay contains an electromagnetic coil. When voltage is applied to this coil, it becomes magnetized and pulls a switch (contact) to either open or close the circuit. --- 🔸 What is a Contactor? A contactor is a heavy-duty switch used to control high-power equipment like motors, pumps, compressors, and lighting systems. ⚙️ Features of Contactor: Handles high current – from 9A up to 800A or more Operates on 230V or 415V AC Built for frequent switching of heavy loads Found in motor starters, elevator drives, and power circuits 🔄 How It Works: Just like a relay, a contactor has an electromagnetic coil. When energized, it closes the main contacts – allowing high power to flow from L1/L2/L3 (input) to T1/T2/T3 (output). --- ✅ Final Thoughts: 🔹 Use a Relay when you’re controlling small signals in automation or control panels. 🔸 Use a Contactor when switching large electrical loads like motors and compressors. Choosing the right one is critical for safety, efficiency, and system performance. --- #RelayVsContactor #ElectricalBasics #ControlSystems #ElevatorTechnician #IndustrialAutomation #MotorControl #ElectricalEngineering #PanelWiring #HVACSystems #PLCControl #AutomationEngineer #EngineeringExplained

🔴 The Spanish power system collapsed within seconds following a double contingency in its interconnection lines with France. First, a 400 kV line disconnected, and less than a second later, a second line also failed, suddenly isolating Spain while it was exporting 5 GW of power. The frequency rose abruptly, triggering the automatic disconnection of approximately 10 GW of renewable generation, programmed to shut down when exceeding 50.2 Hz. This led to a sudden energy shortfall, a sharp frequency drop, and within just nine seconds, a total system blackout. 🪕 The causes of the incident are attributed to low rotational inertia (only about 10 GW of synchronous generation online), identically configured renewable protections that reacted simultaneously, reserves that were inadequate for such a high share of renewables, and an under-dimensioned interconnection with France. Could this have been avoided? Several measures could help prevent similar situations in the future, such as requiring synthetic inertia in large power plants, reinforcing the interconnection with France, and establishing a fast frequency response market, among others. 💡 In this context, Battery Energy Storage Systems (BESS) are more essential than ever. These systems can provide synthetic inertia, ultra-fast frequency response, and backup power in critical situations—capabilities that today’s renewable-dominated system cannot ensure on its own. By reacting in milliseconds, BESS help stabilize the grid during sudden frequency deviations, preventing massive disconnections and buying time for other reserves to activate. Their strategic deployment, combined with appropriate regulation, would make these systems a cornerstone of a more secure and resilient future power system. ... ✋️Please note that this post was written based on the information published on or before its release. Root cause analysis is still ongoing and updates will be released with the outcomes of the investigation. The goal is to show the features that can be provided by BESS within the wide portfolio of solutions applicable in these cases. All inisghts are highly welcome and appreciated in order to enrich our collective understanding. ... 📸 Reid Gardner Battery Energy Storage System (Nevada, USA) A real-world example of how BESS ensures grid stability by delivering synthetic inertia and fast frequency response—essential in a renewable-heavy energy mix.

The most ⚡CRITICAL⚡ moment for an Electric Motor... 🏁 STARTING 🏁 Two key challenges arise: ❌ High Inrush Current ❌ Mechanical Stress To mitigate these effects, various starting methods are used, depending on factors like motor size, application, and power supply. Here are the three most common motor starting methods: 1️⃣ Direct On-Line (DOL) 📖 Description: The motor is directly connected to the power supply, receiving full voltage, which results in high starting torque. ✅ Advantages: ✔ Simple and cost-effective. ❌ Disadvantages: ✖ Draws high inrush current (6-8 times the full load current), causes mechanical stress, and may lead to voltage dips in the system. ⚙ Application: ✔ Suitable for small motors (below 2.2 kW) where high starting current is not a major concern. 2️⃣ Soft Starter 📖 Description: An electronic device that gradually increases the voltage to the motor using thyristors or solid-state switches, effectively reducing inrush current and mechanical stress. ✅ Advantages: ✔ Ensures smooth acceleration, allows adjustable starting time, and minimizes mechanical wear. ❌ Disadvantages: ✖ No torque control after startup and is more expensive than conventional starters. ⚙ Application: Suitable for motors that start under load or in sensitive applications where smooth startup and minimal mechanical stress are crucial. 3️⃣ Variable Frequency Drive (VFD) 📖 Description: A VFD regulates the frequency and voltage supplied to the motor, enabling controlled acceleration from zero to the desired speed. This ensures smooth operation and better energy efficiency. ✅ Advantages: ✔ Provides full control over starting torque and speed ✔ Energy-efficient, reduces mechanical wear and tear ❌ Disadvantages: ✖ Higher cost and more complex control system ⚙ Application: ✔ Ideal for applications requiring precise speed control, such as conveyors, pumps, and fans. --- 🏅 Special Mention 🏅 4️⃣ Star-Delta Starting 📖 Description: Initially, the motor starts in a star (Y) configuration, lowering the voltage across each winding to 1/√3 of the line voltage. After startup, it transitions to a delta (Δ) configuration for normal operation. ✅ Advantages: ✔ Reduces inrush current to approximately 1/3 of DOL, minimizing stress on the motor and electrical system. ❌ Disadvantages: ✖ Lower starting torque (only 1/3 of full torque) ✖ More complex wiring compared to DOL ⚙ Application: ✔ Best suited for medium-sized motors (above 3 kW) where limiting inrush current is essential. 🔹 Legacy Starting Methods: 5️⃣ Auto Transformer Starting 6️⃣ Resistor Starting (Primary Resistor) 7️⃣ Rotor Resistance Starting (For Wound Rotor Motors) #motor #startingmenthodmotor #toppostelectrical #electricalengineering #material

April 6th: A bright spring day in Germany, one that perfectly illustrates the need for battery storage systems. Like so many other sunny days, PV generation in Germany covered a large portion of the electricity demand for several hours in the middle of the day, thanks to the cloudless sky and millions of solar modules. But there is a darker side to the sunshine. Large amounts of daytime solar can overload the grid and cause severe electricity price fluctuations: on April 6th, intraday electricity prices dropped to -200€/MWh at their lowest point. In cases where more electricity is generated from solar energy than the grid can handle, grid operators regularly require solar installations to curtail their production. This means that energy that could otherwise be made available to consumers cannot be used. And when the sun goes down, most of the demand must quickly be met with flexible sources. This adds an extra layer of complexity: deciding which conventional power plants can be shut down during the day and switched on again in the evening is a careful balancing act. This is precisely the situation where battery energy storage systems (BESS) can bridge the gap, with several advantages: - By storing part of the solar energy at peak generation times and dispatching it later, BESS can help shift the curve to more closely align with evening demand. - Better management of volatile generation from renewables also helps keep prices stable. - Provided they are close to the overproducing solar systems, BESS contribute to grid stability by helping balance supply and demand. Of course, there is no one-size-fits-all technology. A secure and flexible energy system needs a diverse mix. But batteries are playing an increasing role, especially as they become more and more affordable. We at RWE are harnessing the benefits: we have 1.2 GW of installed BESS capacity worldwide, of which nine systems totalling 364 MW of capacity operate in Germany alone. We’re scaling fast, with new large-scale projects recently commissioned in Germany and the Netherlands. And we have just decided to build a BESS facility in Hamm with an installed capacity of 600 megawatts. So, let’s continue to make the most of those sunny days — by creating the right framework conditions to build up affordable and flexible support.

🔌 How to Read an MCB Nameplate? 🔌 Understanding Miniature Circuit Breaker (MCB) nameplate data is crucial for selecting the right breaker and ensuring electrical safety. Here’s a breakdown of the key information printed on it: ✅ Model Number (e.g., C60N): Identifies the product series. ✅ Class & Current Rating (e.g., C20): ‘C’ represents the tripping curve, and ‘20’ indicates the rated current in amperes. ✅ Operating Voltage (e.g., 400V~): Maximum voltage the MCB can handle. ✅ Breaking Capacity (e.g., 6000): The maximum fault current the MCB can safely interrupt without damage. ✅ Energy Class (e.g., 3): Efficiency of arc extinguishing and energy limitation. ✅ Terminals & No. of Poles: Determines how many circuits the MCB can protect. ✅ MCB Operation Symbol: Indicates the tripping mechanism. ✅ Status Indicator (ON/OFF): Shows the current state of the breaker. 📌 Why is this important? Proper MCB selection prevents overloads, short circuits, and equipment damage. Understanding these markings ensures compliance with safety standards and optimal circuit protection. #ElectricalSafety #MCB #PowerDistribution #Engineering #SolarEnergy #SchneiderElectric

Ditching Diesel for Hydrogen: The Future of Sustainable Energy 🟦 What is a hydrogen microgrid? a- Microgrids are self-sufficient electric power grids, often used in remote areas. They incorporate a combination of energy generation, storage, and load management, making them a reliable and effective power source. b- Introducing hydrogen to microgrids provides long-term storage that batteries cannot. c- The excess renewable energy is converted to hydrogen using hydrogen electrolysers. The excess hydrogen is stored for use during high-demand and low-supply periods. d- The stored hydrogen generates electricity as and when required, using a hydrogen fuel cell. 🟦 An example of a microgrid: - To showcase the economical and efficient benefits of hydrogen storage, Koh Jik is selected, a small off-grid island in Thailand. - Since 2004, the island has been powered by a solar/diesel/battery microgrid that supplies electricity to 100 households and 300 inhabitants. It's one of Southeast Asia's oldest and most economically feasible microgrids. - In the pilot study, hydrogen was shown to be more cost-effective than diesel by the time of the study (2020). 40kW of photovoltaic panels and a lead acid battery system cover 50% of the island's energy demand, while a diesel generator provides the remainder. - After 15 years, the system requires an upgrade. The initial plan was to incorporate solar panels and new batteries, raising the renewable energy contribution to an impressive 85%. Nevertheless, 15% of the power would depend on a diesel generator. -Koh Jik would have enough solar energy available to meet its demand in this setup. Still, due to insufficient batteries' long-term storage, 30% of solar generation throughout the year needs to be reduced. -Instead of wasting excess solar energy, a modular hydrogen electrolyzer can convert it into hydrogen. 🟦 The World Bank recently reported that the total investment in mini-grids in Africa and Asia currently amounts to 5 billion US Dollars. This amount is expected to rise to 220 billion US Dollers, which is required to connect 500 million people to 210,000 mini-grids in these regions by 2030. 🟦 Diesel and Hydrogen kilowatt-hour compared: ⏭️ Diesel kilowatt hour: (1) Gas station = $0.25/kWh (2) Fuel logistics = $0.06/kWh Fuel cost = $0.31/kWh (3) Genset = $0.22/kWh (4) Maintenance = $0.09/kWh Conversion = $0.31/kWh (5) Total = $0.62/kWh ⏭️ Hydrogen kilowatt hour: (1) Electrolyser = $0.29/kWh (2) H2 Components = $0.1/kWh (3) Hydrogen storage = $0.06/kWh Hydrogen Fuel cost = $0.45/kWh (4) Hydrogen Fuel Cell = $0.13/kWh (5) Maintenance = $0.03/kWh Conversion = $0.16/kWh (6) Total = $0.61/kWh Reference: Ditching the Diesel: Hydrogen Microgrids, Thomas Chrometzka, Tanai Potisat & Aoibhin Quinn, Enapter Newsroom, June 22, 2020.  ✅ My posts reflect my personal perspective, knowledge, experience, and advice. 👇Could hydrogen microgrids be a replacement for diesel microgrids?