- “The key to the AC to DC transition is precision measurement technology that captures heat and drift.”

The energy paradigm is undergoing a dramatic shift globally. The explosive power demand from AI data centers and the expansion of electric vehicles (EVs) are placing unprecedented pressure on power infrastructure that has remained stagnant for decades. We have reached a point where the challenge has shifted from simply producing more electricity to determining how to deliver it in a 'stable' and 'efficient' manner.

This magazine met with Manager Lee Seung-kyu, who is in charge of energy metering and power grids at Marknica Korea, to discuss the technical challenges engineers face and their solutions during the digital transformation (DX) of aging power grids.

Warning of the Aging Power Grid: Evolution to 'Digital Substations' Is Inevitable

Q. The aging of power infrastructure both domestically and internationally is a serious issue. How do you feel about this in the field?

In the United States, the aging of power grids is so severe that those built in the 1970s are still in operation. Korea, too, has reached the replacement cycle for transmission and distribution facilities that have been installed for over 30 to 40 years. The problem is that past power grids were not designed with high-load devices, such as AI data centers or rapid chargers, in mind, as they are today. A significant number of the recently frequent apartment complex blackouts and transformer accidents occur because these aging facilities cannot withstand the overload.

Ultimately, the solution is to upgrade existing analog substations into 'digital substations' based on IEDs (Intelligent Power Devices) and FRTUs. Establishing systems that monitor power flow in real time and detect warning signs to prevent accidents is the biggest trend in the current power market.

The Coexistence of AC and DC, and the Paradox of 'New and Renewable Energy'

Q. The DC (direct current) transmission and distribution market has recently been attracting significant attention. What changes are taking place from the existing AC (alternating current)-centric system?

This is due to renewable energy and ESS (Energy Storage Systems). Electricity generated from sources such as solar power is fundamentally DC. Significant energy loss occurs during the process of converting it to AC to be used in the existing power grid. While the construction of DC transmission and distribution networks is becoming more active to maximize efficiency, DC, unlike AC, faces the challenge of 'instability in its generation itself.'

Since power is cut off when the wind stops or the sun sets, an organic integration with an ESS to compensate for this is essential. In this process, the technology to ultra-precisely measure and control the flow of power has become far more important than in the past.

Engineer's Homework: Harmonic Analysis and 'Lossless Waveform Capture'

Q. What is the most challenging technical challenge for engineers in power quality management?

Power quality degradation due to sudden load fluctuations, that is, the harmonic problem. To analyze this accurately, a Fast Fourier Transform (FFT) must be performed, and even the slightest data loss is unacceptable when converting the fundamental analog signal to digital.

It is the so-called 'Lossless Waveform Capture' technology. This is because if the signal is distorted, the analysis results themselves become skewed. In the field, even if specifications on datasheets appear similar, there are often differences in sampling speed and precision when applied to actual systems. The reason ADI's solutions are considered "high-quality" in the field is precisely due to this integrity of the source data.”

Q. It seems that the issue of 'temperature drift' cannot be overlooked in the measurement process either.

“That is correct. Particularly in DC measurements involving high currents, heat generated by shunt resistors introduces errors into the measurement values. If the system indicates that electricity is being used when it is not, or vice versa, the reliability of the entire power grid collapses. Recently, with the release of chipsets that offer extremely low error rates even with temperature fluctuations, stable measurements have become possible even in the extreme environments of summer and winter.”

Design Simplification: “Removing peripheral circuits is key to competitiveness”

Q. One of the recent trends in hardware design is 'high integration.' How is this manifesting in power device design?

In the past, numerous components such as filters and amplifiers had to be haphazardly attached between the sensor and the ADC. However, recently, solutions that maximize the input impedance of the ADC itself to enable direct interface with sensors have become the mainstream.

For example, products like the AD4858 enable PCB area reduction by drastically decreasing peripheral circuitry. A smaller board means more than just a reduction in physical size; it creates a virtuous cycle that reduces signal interference, lowers manufacturing costs, and increases the reliability of the final product.

Key Keywords of the Future Power Grid: 'Safety' and 'Localization'

Q. Safety is the top priority for power grid infrastructure. What other factors should be considered during the design?

It is isolation. Isolation design is essential to protect control circuits in high-voltage power grids. Technologies like ADI's iCoupler help maintain product size while simultaneously isolating power and data.

Furthermore, since power specifications (voltage, frequency) vary by country, it is crucial to provide flexible support. Beyond simply selling chips, Maknica Korea is staking its future on technical support that involves customizing software and calibration to meet the specific requirements of the Korean market.

[Editor's Note] Through a conversation with Manager Lee Seung-kyu, we were able to confirm that power grid modernization is not merely a replacement project, but a 'high-tech industry' combining ultra-precision semiconductor technology and software. In an era where power efficiency is synonymous with national competitiveness, the invisible struggle of engineers is ongoing at this very moment.