The field of industrial automation continues to advance rapidly, driving efficiency, productivity and cost reductions. However, all of the associated components place more stress on the electrical grid, making efficient power conversion technology a necessity. In this white paper from YAGEO Group, explore the critical function of passive microelectronic components in power supply applications for industrial automation.
Introduction
The shift toward industrial automation has led to an exponential increase in power demand, necessitating robust and efficient power conversion solutions. As automation systems rely heavily on power electronics, addressing efficiency and reliability challenges is crucial. Passive components are essential for ensuring stable operation, minimizing losses, and mitigating power disturbances that could impact industrial operations and the broader electrical grid.
1 Power Conversion Challenges in Industrial Automation
1.1 Grid Stress and Power Quality Issues
Automated manufacturing lines, robotic systems, and variable frequency drives (VFDs) introduce harmonic distortions, transient spikes, and unbalanced loads, leading to power quality issues. This increased demand and distortion result in grid inefficiencies, voltage sags, and potential equipment failures.
1.2 Efficiency and Energy Consumption
Power conversion stages need to minimize losses and ensure high power efficiency. The key to achieving this lies in effective EMI suppression, power factor correction, DC-DC conversion, and output filtering.
2 Passive Components in Power Conversion Stages
2.1 Electromagnetic Interference (EMI) Mitigation
Industrial automation equipment generates significant high-frequency noise, which can disrupt nearby electronic systems and lead to regulatory non-compliance. Passive components such as:
- EMI suppression capacitors (Class X and Y) help filter out conducted noise. These capacitors are designed to handle transient voltage spikes and suppress differential and common-mode noise.
- Common-mode chokes are essential in reducing electromagnetic emissions from power lines. They consist of two windings on a magnetic core, which cancels common-mode noise while allowing differential signals to pass. Their proper selection and placement significantly impact compliance with EMI standards.
- Inductive filters prevent unwanted noise from propagating through power lines, reducing conducted and radiated emissions.
Advanced film and multilayer ceramic capacitors (MLCCs) play a crucial role in reducing EMI while maintaining high reliability in industrial environments. Proper layout and selection of these components ensure compliance with EMI regulations such as CISPR and IEC standards.
2.2 Power Factor Correction (PFC) for Grid Efficiency
Poor power factor, caused by inductive loads and non-linear industrial automation systems, leads to excessive reactive power, increased grid losses, and potential utility penalties.
- Power factor correction capacitors enhance the displacement power factor by compensating for inductive loads, thereby ensuring more efficient utilization of electrical power.
- Inductors and PFC chokes smooth current waveforms, reducing harmonics and improving the efficiency of AC-DC conversion. These inductors help shape the current waveform to follow the voltage waveform, reducing total harmonic distortion (THD).
- Passive damping networks help stabilize PFC circuits, preventing oscillations and voltage spikes that can degrade component life and system performance.
- Active damping networks dynamically reshape the current waveform, allowing for more efficient and low-loss power factor correction.
Automation systems can reduce grid stress, minimize power losses, and ensure regulatory compliance by integrating optimized passive PFC components. High-power industrial applications typically implement active PFC combined with passive filtering to achieve higher efficiency.
2.3 DC-DC Conversion: Voltage Regulation and Stability
Industrial automation applications often require multiple DC voltage levels for control and motor drive functions. Efficient DC-DC conversion is critical for stable operation.
- Power inductors enable efficient energy storage and transfer in buck and boost converters, controlling ripple current and improving transient response.
- MLCCs and aluminum electrolytic capacitors ensure stable voltage regulation and reduce ripple in DC-DC circuits. MLCCs offer low equivalent series resistance (ESR), which improves transient response and filters high-frequency noise.
- Capacitor power arrays are essential for high-frequency applications and resonant power converters. These capacitor arrays offer low equivalent series resistance (ESR) and high capacitance density, making them ideal for high-power applications that require efficient energy transfer. Their ability to handle high ripple currents and voltage fluctuations improves system efficiency, reduces losses, and enhances thermal performance in resonant power conversion circuits.
- Transformers for LLC Resonant Converters are crucial in high-efficiency DC-DC conversion. By integrating the inductor within the transformer, designers can reduce component count, improve power density, and enhance efficiency by minimizing parasitic losses. This integration enables better magnetic coupling, thereby reducing circulating currents and enhancing the overall performance of resonant converters in industrial automation applications.
Selecting low-loss, high-efficiency passive components in DC-DC converters minimizes heat dissipation, enhances reliability, and ensures efficient power distribution. The choice of core materials in inductors, such as ferrite or powdered iron, directly impacts efficiency and thermal performance.
2.4 Output Filtering for Stable Power Delivery
At the final power conversion stage, output filters ensure the smooth delivery of voltage and current to automation systems, thereby preventing power fluctuations that could disrupt operations.
- LC Filters (Inductor-Capacitor filters) play a crucial role in reducing ripple voltage and high-frequency noise in power supplies. These filters improve transient response, minimize electromagnetic interference, and enhance voltage stability for industrial automation equipment. The inductor in an LC filter blocks high-frequency AC components, while the capacitor smooths the DC output, ensuring a cleaner power supply to sensitive loads.
- Low-ESR capacitors, such as film and Class 1 MLCC, aluminum polymer, and aluminum hybrid polymer, are used to reduce ripple and transient response times, ensuring a stable DC output voltage for sensitive automation equipment.
- Power inductors help suppress noise and stabilize voltage by reducing electromagnetic emissions and preventing ringing in power circuits.
Proper output filtering ensures that industrial automation equipment operates within the required power quality standards, thereby enhancing efficiency and longevity. Implementing multi-stage filtering, combining differential-mode and common-mode noise suppression techniques, can improve performance.
Conclusion
As industrial automation advances, efficient, reliable power conversion becomes increasingly critical. Passive components play a crucial role in mitigating EMI, enhancing power factor, facilitating efficient DC-DC conversion, and stabilizing output filtering. By integrating advanced passive component technologies, industrial automation systems can optimize energy consumption, reduce grid stress, and enhance operational efficiency. Future developments in high-efficiency passive components will continue to support the evolution of industrial automation and power electronics.