Countering Threats from Transients in Magnetics

In the realm of electrical engineering, transients in magnetic components pose significant challenges that can lead to system failures. Understanding and mitigating these threats is crucial for ensuring the reliability and longevity of electrical systems. This article delves into the origins of elec...


Understanding Electrical Transients in Magnetics

Electrical transients are sudden, short-duration spikes in voltage or current. They can arise from various sources such as lightning strikes, switching operations, or inherent instabilities within the system. These transients can cause severe stress on magnetic components, leading to potential malfunctions or catastrophic failures.

 

Causes of Electrical Transients

Electrical transients can originate from external factors like environmental conditions or input/output operations. Internally, they can be caused by the natural response of the system's reactive components: resistors, inductors, and capacitors. These components, governed by the laws of physics, react to changes in state variables, resulting in oscillations, amplification, or decay of signals.

 

Effects on Magnetic Components

Magnetic components, such as transformers and inductors, are particularly susceptible to transients. For instance, transformers can exhibit parasitic components that affect their response to sudden voltage or current changes. These parasitic elements can cause amplification, oscillation, or even breakdown under transient conditions.

 

Mitigating Transient Threats

Effective mitigation of transient threats involves understanding the behavior of magnetic components under dynamic conditions and implementing design strategies to counteract these effects.

 

Component Functions and Response

  1. Resistors: Dissipate energy to manage power levels.
  2. Inductors: Generate opposing voltages to slow current changes.
  3. Capacitors: Absorb or release charge to stabilize voltage changes.

The induced voltage and current in inductors and capacitors are inversely proportional to the circuit's time constant. A smaller time constant means faster energy transfer, which can lead to higher transient voltages or currents.

 

Transformer Design Considerations

Transformers must be designed to handle dynamic impedance transformations and provide necessary isolation. Realistic transformer models must account for parasitic components, which can significantly influence their behavior during transients. High voltage transformers, for instance, are prone to series resonance due to leakage inductance and self-capacitance, leading to oscillations and potential saturation.

 

Practical Mitigation Techniques

  1. High Bandwidth Instruments: Use to detect latent transient amplification and persistent ringing during normal operations.
  2. Worst Case Analysis: Evaluate bias currents and flux density for worst-case scenarios, including maximum voltage and temperature conditions.
  3. Current Transformer Verification: Ensure that protection circuits can detect transient overcurrents despite reduced output due to saturation.
  4. Residual Magnetization Control: Verify that residual magnetization does not impair operation, ensuring sufficient headroom for magnetization.
  5. Design of Experiments (DOEs), Risk Reduction Tests (RRTs), and Accelerated Stress Tests (ASTs): Implement these throughout the design stages to mitigate risks effectively.
  6. Protective Components: Use components like MOVs (Metal Oxide Varistors) to safeguard circuits from lightning-induced transients.

 

Countering threats from transients in magnetics requires a thorough understanding of the underlying causes and the implementation of robust design strategies. By employing high bandwidth detection instruments, performing worst-case analyses, and integrating protective measures, engineers can significantly reduce the risk of transient-induced failures in magnetic components. Adopting a proactive approach to design and testing ensures the resilience and reliability of electrical systems in the face of transient threats.

Published on 22 May 2020 by Victor W. Quinn / Stéphane PERES

INNOVATIVE LOW PASS FILTERS

Low-pass filter solutions are mainly used for EMI suppression in electronics systems. Exxelia Technologies (ex-Eurofarad), part of Exxelia Group, has developed several ranges of miniature filters with different low-pass configuration (C, L, Pi, T, 2xPi, 2xL and 2xT) mainly intended to protect electronic equipment from interferences. Exxelia Technologies produces sophisticated filters assembling Exxelia Group’s manufactured ceramic capacitors (X7R/ NPO) with ferrite inductors or winding cores in a shielding case. This solution’s main benefits are performance, reliability and optimal traceability. Considering a filter in a shielding case implies a good metallic package to insure high shielding performances with attenuation up to 10 GHz. Among options, Exxelia offers glass sealing, steel or kovar package using tin, silver or gold plating treatments to withstand any thermally or mechanically challenged applicaiton. Exxelia offers innovative EMI suppression filter solutions providing great shielding performance including the FC030 feedthrough mounted on shielding enclosure and FCM030 series designed to prevent EMI on printed circuit board. FC030 series is feedthrough filter allowing to prevent not only EMI conduction but also EMI radiation on power supply or data signals designs up to 200V. FC030 insertion loss can be 20dB at 1MHz to reach 70dB up to 10 GHz. FC030 series is extremely performant on low frequencies applications. On the other hand, FC030 can offer very low capacitance values starting from 5pF allowing to protect high bandwidth data signals. Operating temperature from -55C° up to +175C°. FC030 series is ESA qualified.   FCM030 features same design and performances’ as FC030 and is intended for surface mount devices. FCM030 is packaged in full metallic silver plated allowing optimal contact with ground plane that improves the interferences flow to the ground. The series particularly fit for amplifiers, radars, sensitive HMI, accurate measuring.

A “Game Changer” Rectangular Aluminum Electrolytic Capacitor, Called Cubisic SLP

Cubisic SLP is the new rectangular aluminum electrolytic capacitor from EXXELIA, a world leader in manufacturing and designing capacitors. Their products are known for their high performance and reliability, which has made them the choice of many of the world's leading avionics engineering companies. However, they were looking for a new, more reliable capacitor that could withstand even greater vibration and altitude than any previous capacitor. They needed a stronger, more reliable product with a life expectancy that matched the customers' projects. Product description : Cubisic SLP is among the industry's first aluminum electrolytic capacitors designed with flat technology. The result is a lighter, smaller rectangular shape with increased surface area, which improves its capacity. As a result, it can accommodate more energy at almost any altitude or vibration level.    This makes Cubisic SLP ideal for applications where added durability is required, such as cockpits and power generation functions on aircrafts, along with being well-suited for radars and laser systems in up to 50G vibration conditions and 92K feet altitude resistance. ✅ Low profile printed circuit mounting ✅ Possible mounting with 45 x 12 bracket (A691057) ✅ Possible thermal dissipation per conduction through a lower and upper surface ✅ Switch mode power supplies, impulse current ✅ Withstands more than 92,000 feet altitude ✅ Sleeve optional Cubisic SLP comes in three sizes, is made with high-quality aluminum foil and impregnate with electrolyte. It has 2 terminals: anode, cathode. What makes Cubisic SLP so different? An example of one of the advantages of this technology is that designing a capacitor with a traditional cylindrical shape, means that 2/3 of its volume is empty, compared to this new flat design. As a result, more capacitors are packed into the same volume, thus increasing the density. What’s a Rectangular Aluminum electrolytic capacitor, and why is that important? What’s, a Rectangular Aluminum electrolytic capacitor : In short (no pun intended), a rectangular electrolytic capacitor is one of those components that keeps your electronics running safely, your ship floating, and your aircraft operating properly.  A Rectangular electrolytic capacitor is a component that essentially stores electrical energy in the form of an ‘electrolyte’. It’s made up of three layers: two aluminum sheets separated by an electrolyte solution and encased in a steel or porcelain container. And as the name implies, it’s shaped like a rectangle. It's widely used in different industries because of its reliable and cost-effective protection, which makes it the go-to component for many commercial, industrial, and aerospace uses. Rectangular aluminum electrolytic capacitors are mostly used in military aircrafts, missiles, and nautical transportation, as well as space navigation systems. In these applications, reliability is crucial for the safety of millions of people, so it is essential to choose a reliable product that offers high performance and quality. So if you find yourself with any of those use cases and/or engineering projects on your hands that require high performance and quality under extreme environments, look no further than this capacitor! Why is that important? As an example, when a military fighter jet accelerates, it can experience up to three times the force of gravity. While this is an impressive feat, consider what it does to the components in the vehicle. One such component is a capacitor. While it might seem like just a small piece of circuitry, capacitors are responsible for a variety of functions in your fighter jet, including: > Powering the radar antenna > Controlling engine performance > Controlling flight-related functions like fuel injection and landing gear operation This is because of the way they deal with heat buildup, which is an issue with capacitors in high-performance vehicles, especially on aircrafts where rapid acceleration can cause significant damage to any component. That's helpful in the cockpit, where the controls are exposed to this kind of force; a control that has to withstand up to three times the force of gravity will last longer than one that isn't designed for this. In other places on a military jet—such as power generation functions—the same principle applies: if something is going to be exposed to extreme forces (like vibration or acceleration), it needs to be strong enough not to break easily. That's why these capacitors are a great choice: they can handle extreme conditions without losing their effectiveness over time. That's why Exxelia takes the time to test every single capacitor we sell to our customers. How does its ability to withstand varying vibration levels and altitudes make a difference to the aerospace industry? What makes a rectangular aluminum electrolytic capacitor so effective for aerospace companies? The answer: They're made from high-quality material—pure and simple. But the difference between standard capacitors and those for the aerospace industry goes far beyond that. For the aerospace industry, the ideal capacitor would endure extreme temperatures, have a wide range of voltage tolerances, and withstand varying vibration levels, all while maintaining its effectiveness at an altitude of 19,000 meters—which is where Cubisic SLP comes in. As an electrolytic capacitor with an expanded operating temperature range and a very high resistance against vibration and altitude changes, this product has been able to make a huge difference in how well aircrafts can stay in control. Not only does it help prevent power outages, but also it helps avionics to stay functional when they are subjected to drastically changing conditions. Cubisic SLP capacitors are designed to handle extreme environments, which makes them incredibly versatile—and incredibly useful. From aeronautics to medicine, these capacitors can help your projects meet just about any challenges. Where can I find out more about EXXELIA’s Cubisic SLP range? Radial aluminum electrolytic capacitors cubisic SLP Radial aluminum electrolytic capacitors cubisic HTLP Radial aluminum electrolytic capacitors alsic 145 20g Radial aluminum electrolytic capacitors alsic 20g Radial aluminum electrolytic capacitors cubisic lp Radial aluminum electrolytic capacitors cubisic   TECHNICAL PAPERS (Electrical characterization of cubisic SLP capacitors) DOWNLOAD DATASHEET