Vietnamese Distribution Grid Automation System a Winning Project

Vietnam Electricity Group’s Ho Chi Minh City Power Corp. (EVNHCMC) deployed a distribution automation system that facilitates automatic—and very quick—fault detection and handling with a success rate of more than 90%. The project improved EVNHCMC’s reliability immensely, leading to its selection as POWER’s 2024 Smart Grid Award winner.

Vietnam Electricity Group (EVN) operates five power distribution companies in Vietnam, including Ho Chi Minh City Power Corp. (EVNHCMC). EVNHCMC is responsible for delivering a stable, safe, and reliable power supply to Ho Chi Minh City, which is the leading center for finance, culture, and services in Vietnam, playing a major role in the country’s economic development. As a result, EVNHCMC’s performance is of vital importance. “We must constantly research new technologies and promote innovation initiatives to continue to maintain and upgrade the smart level of the grid,” Dr. Luan Quoc Hung, deputy general director of EVNHCMC, told POWER.

In 2014, EVNHCMC embarked on a grid improvement program by researching and piloting Distribution Automation System (DAS) technology on eight medium-voltage feeders, which involved two overhead lines and six underground cables. Following its success, the implementation of DAS technology was expanded in 2016.

The DAS project aims to automate EVNHCMC’s entire 22-kV power distribution network. The DAS software, provided by Survalent, enables real-time response to faults in the grid through its Fault Location, Isolation, and Service Restoration (FLISR) functionality, significantly improving the reliability of the power supply in Ho Chi Minh City.

Prior to FLISR implementation, a significant number of customers (often from 6,000 to 8,000) could be affected by an electrical fault, with an average power outage duration of approximately 120 minutes, Dr. Hung explained. This was due to EVNHCMC’s limited medium-voltage grid automation capabilities. For example, the company had only one or two switchgear devices equipped with supervisory control and data acquisition (SCADA) functionality. It also lacked dedicated automation software. Manual fault troubleshooting required workers to go into the field to identify and address issues through visual inspection, manual operations using hot sticks, and other physical means.

Now, after the deployment of DAS, when an electrical fault occurs, the system empowers operators to automatically detect and isolate the affected area, and then restore power almost instantaneously to unaffected areas without manual intervention. “Currently, with the DAS in operation, by segmenting lines into three to five sections, the number of affected customers has been reduced to approximately 1,000 to 1,500,” Dr. Hung proclaimed. “Additionally, the outage duration for customers in unaffected areas is now less than one minute. Furthermore, the remote operation facilitated by the DAS has significantly enhanced EVNHCMC’s grid workers’ safety, particularly during severe weather conditions such as storms, typhoons, and floods.”

Meanwhile, EVNHCMC also worked in partnership with Alstom (now GE Vernova) to deploy a SCADA/DMS (Distribution Management System). The SCADA/DMS aims to improve the management of Ho Chi Minh City’s power grid. The project was a collaboration with the following main purposes:

“Alstom-GE is a partner with mature experience in providing SCADA/DMS software,” Dr. Hung noted. “The SCADA/DMS project assists EVNHCMC in power grid management, particularly in the areas of remote monitoring, control, and operational optimization.”

Concerning Survalent, Dr. Hung said: “Survalent has been a partner with EVNHCMC since the very first DAS pilot project in 2014 and throughout its complete implementation. Additionally, Survalent is also the partner that assisted EVNHCMC in establishing a backup control center—completed in 2021—which operates independently and in parallel with the main control center [Figure 1].”

Within the DAS project, intelligent switchgear devices, which include a combination of physical equipment and Intelligent Electronic Devices (IEDs), play a crucial role in enabling grid automation. EVNHCMC has installed 10,244 switchgear devices across its 22-kV distribution network. These devices include 1,679 circuit breakers, 4,839 ring main units (RMUs), 1,510 reclosers, and 2,216 load break switches (LBSs). Reclosers and LBSs are primarily utilized for overhead power lines, while RMUs are employed for underground networks.

EVNHCMC has also undertaken a comprehensive network reconfiguration initiative, segmenting medium-voltage feeders into smaller sections. It started in 2016 with each of its feeders being divided into three segments with at least one tie point. The segmentation criteria tried to limit each segment to a load of less than 100 amps and/or fewer than 3,000 customers served. Beginning in 2021, each feeder was further segmented into five sections with at least two tie points. The criteria in this endeavor limited each segment to a load of less than 50 amps and/or fewer than 1,000 customers served.

To better understand how the DAS works, Dr. Hung provided an example of how a fault might be identified, isolated, and power restored to unaffected portions of the system. If a circuit breaker were to trip, accompanied by a fault indicator signal, he explained, depending on the downstream configuration, operators might look at a recloser immediately down the line to see if it also had a fault indicator signal. If it did not have a signal, the fault would be identified within the segment between the circuit breaker and the recloser.

In this case, the DAS would send a command to open the recloser to isolate the faulted segment. It would then send a command to close a previously open LBS to restore power to the unaffected area via a different circuit breaker. The process would be carried out very quickly, usually in less than a minute, thereby minimizing the number of affected customers and the duration of the power supply interruption.

The DAS Smart Grid project also reduces the frequency, duration, and complexity of onsite fieldwork. By focusing on remote automated operations, it elevates the overall safety level for employees, particularly those working in severe weather conditions such as storms or floods.

Perhaps the biggest obstacle to EVNHCMC’s smart grid upgrade was deciding what technology to implement. As previously noted, EVNHCMC launched its pilot program in 2014, but its research on smart grid technologies began at least four years earlier. Following much analysis, the company ultimately outlined a detailed roadmap in 2012.

Cybersecurity ranked very high among the concerns EVNHCMC had defined. Dr. Hung said information technology (IT) and operational technology (OT) network systems have been equipped with specialized security solutions, ensuring compliance with standards such as ISO 27001 for IT networks and ISO 27019 for OT networks. “We also focus on the cooperation with state management agencies on cybersecurity as well as conducting regular drills,” he said.

EVNHCMC also placed a priority on developing in-house knowledge and understanding of its smart grid technologies. Training and the organizational structure have been paramount to success. “We have established specialized departments to perform the mastery of new technologies from all stages: design, procurement, installation, configuration, programming, commissioning, repair, and maintenance,” said Dr. Hung. “All core projects undergo a pilot phase, followed by evaluation, and then mass deployment,” he explained.

Metrics show that the DAS project has markedly improved grid reliability. In 2015, EVNHCMC’s System Average Interruption Duration Index (SAIDI) was a whopping 720 minutes. By 2019, it had dropped to 58 minutes, and last year, it came in at a minuscule 15.2 minutes. Likewise, the company’s System Average Interruption Frequency Index (SAIFI) experienced a significant improvement in the years from 2015 to 2023, going from 6.72 to 0.18 during the timeframe.

For comparison, the U.S. Energy Information Administration said in its most recent report that the U.S. distribution system’s average SAIDI value including all events was 335.5 minutes per customer in 2022. If major event days were excluded, the figure dropped to 125.7 minutes per customer, which is still much worse than EVNHCMC’s score. The U.S. distribution system’s average SAIFI value in 2022 including all events was 1.4 power interruptions per customer and 1.1 interruptions per customer with major events excluded, a far cry from the 0.18 EVNHCMC tallied.

And EVNHCMC’s customers have noticed the improvement. “Over the years, EVNHCMC’s power supply ensured has consistently translated into improved customer satisfaction. Notably, the corporation has received overwhelmingly positive feedback from VIP customers such as Intel, Samsung, commercial centers, and industrial parks,” said Dr. Hung. “To objectively assess customer satisfaction, EVNHCMC annually conducts surveys through an independent consultancy firm. In 2019, the customer satisfaction score in Ho Chi Minh City reached an impressive 8.66 out of 10 points,” he added.

Meanwhile, the Singapore Power Grid’s Smart Grid Index recognized EVNHCMC with a perfect score—4 of 4 points—in the area of grid monitoring and control in 2022. The Vietnamese Ministry of Information and Communications acknowledged EVNHCMC’s digital transformation journey by making it the first company in Vietnam to receive the prestigious “Digital Enterprise” certification. Said Dr. Hung, “The DAS project contributes to building a culture of ‘technology development and innovation’ within EVNHCMC.”

In light of EVNHCMC’s incredible accomplishments, POWER is pleased to recognize the company’s DAS project as the winner of its 2024 Smart Grid Award. Congratulations to everyone involved!

—Aaron Larson is POWER’s executive editor.