Currently Nanda Aoto Technology's independently developed mid-to-large-scale PLC products have successfully broken the decades-long market monopoly held by France's Schneider and America's GE in the hydropower industry. 。

Nanjing Aotuo Technology's independently developed programmable controller (PLC) has achieved groundbreaking progress in its core CPU chip and embedded real-time operating system, and is now deployed at Develop programmable controller embedded software on domestically produced chips like Loongson and open-source embedded Linux operating systems, achieving independent and controllable breakthroughs in the core hardware and software technologies of PLCs. 。

In addition, Nanjing Aoto Technology addresses the information security needs of hydroelectric power station computer monitoring systems. Leveraging the unique characteristics of the industry, they conduct research on programmable controller cybersecurity, focusing on aspects such as security and practicality. Establish a dedicated hardware and software defense system tailored to the pathways and characteristics of external attacks on hydropower systems. 。

Nanda Aotuo Technology's PLCs (Programmable Logic Controllers) and SCADA systems have been widely deployed in more than 40 hydropower stations. , having accumulated extensive field application experience, the product has demonstrated stable and reliable performance in real-world operations. In particular, the Chinese-localized programming interface is intuitive and easy to understand, while the software boasts powerful functionality and flexible configuration options—earning unanimous recognition from owners, design experts, and system integration partners. As a domestic manufacturer that independently develops cutting-edge PLC technology with fully independent intellectual property rights, Nanda Aoto Technology will continue to make its rightful contributions to the ongoing effort of localizing PLC systems for China's hydropower stations.

Introduction to Self-Controllable Products

Based on the domestically developed Kylin operating system Self-reliant and controllable Hydropower Station Monitoring Software

Today, hydroelectric power stations have adopted computer-based automation and monitoring systems to control their electricity-generation processes. This not only enhances the stations' level of automation and improves the quality of power supply but also boosts operational safety, labor productivity, and overall economic efficiency.

The application of computer-based monitoring technology in hydropower stations has dramatically transformed the way these facilities are staffed, enabling full automation for the first time. This innovation has significantly reduced the physical workload of operators, minimized the number of personnel required to run the station, and substantially decreased the amount of equipment-handling tasks performed by operational staff. As a result, hydropower stations have successfully adopted a "unmanned operation with minimal staffing" model.

Security vulnerabilities and backdoors in computer operating systems are the primary factors directly impacting the safe and stable operation of automated systems. Nanjing University Aotuo's independently developed cross-platform configuration software can run seamlessly on domestically produced Zhongbian Kylin or Galaxy Kylin operating systems. Paired with domestic servers powered by China's Loongson or Phytium processors, this solution truly enables the localization of computer monitoring systems, significantly mitigating security risks—such as viruses, vulnerabilities, and backdoors—posed by Windows operating systems to hydropower plant operations.

Feature Highlights >>>

• This system's software platform runs on a domestically produced hardware platform comprised of the Kirin operating system and Loongson processors.
• Both software and hardware are developed in a platform-based manner;
• The entire network uses Ethernet to exchange data with each other;
• To achieve dual-host redundancy and historical database redundancy configurations, ensuring the system boasts high reliability;
• Strong data processing capabilities, with fast and stable response times;
• The system boasts strong maintenance capabilities, easing the burden on users;
• Open-system design allows for both software and hardware upgrades;
• By connecting to standard databases (such as SQL SERVER, ORACLE, SYBASE, MYSQL, etc.) via "Open Database Connectivity (ODBC)," data can be exchanged with MIS systems.
• It supports standard protocols such as MODBUS TCP and TCP/IP, enabling communication with PLC products from multiple companies including Nanya Aoto, Schneider, Siemens, GE, and AB.

Self-reliant and controllable Programmable Logic Controller (PLC)

In the computer monitoring system of hydropower stations, one of the most critical components is the PLC (Programmable Logic Controller) product, as all automated operational processes in the hydropower station are directed and controlled by it. Increasingly, safety concerns related to PLC products have drawn significant attention from the Ministry of Industry and Information Technology.

Foreign-imported PLC products have continuously exposed vulnerabilities and backdoors, constantly threatening the operational security of industrial control systems. Nanda Aoto Company has developed a large-scale PLC product based on an independently controllable, domestically produced MCU. From the core CPU to all IO and communication modules, every component is fully autonomous and secure. Additionally, the product features dual-machine hot-standby redundancy, power redundancy, and Ethernet communication redundancy. It also incorporates advanced information security encryption for network communications, utilizing China's national cryptographic algorithms to encrypt Ethernet packets in transit. Furthermore, the system binds the MAC addresses of servers accessing PLC data and implements packet filtering, ensuring robust protection and meeting the stringent security requirements of large-scale hydropower stations.

Nanjing Aotuo Technology's independently controllable PLC technical specifications are as follows >>>

• The core CPU features a domestically produced Loongson processor;
• The PLC embedded operating system uses a domestically developed, independently controllable operating system.
• The PLC development and programming software is entirely independently developed and can run in a domestically produced PC environment (featuring domestically made processors and operating systems).
• Embedded application software is entirely developed in-house;
• PLC supports CPU hardware redundancy, power redundancy, network redundancy, bus redundancy, and IO redundancy;
• All modules support hot-swapping;
• Supports up to 32,768 or more I/O device points;
• Surge immunity IEC61000-4-5: 4kV (common-mode) / 2kV (differential-mode);
• Fast transient IEC61000-4-4 ±4kV (power supply) / ±2kV (I/O);
• Electrostatic Discharge IEC61000-4-2: ±15kV (air) / ±8kV (contact);
• Radiation Interference IEC61131-2 30–230 MHz, 10m quasi-peak, less than 40 dB(µV/m) 230–1000 MHz, 10m quasi-peak, less than 47 dB(µV/m)
• Insulation withstand voltage DC 2500V, 2 MΩ or higher;
• Noise Immunity: 1000V (peak-to-peak), pulse width 1µs, 1 minute;
• Operating temperature: -25°C to +55°C.

Hydropower Station Monitoring System Architecture Diagram

The primary functions of PLCs in hydropower automation monitoring systems

1) The PLC collects and processes analog signals. Analog signals are categorized into electrical and non-electrical types. Electrical analog signals primarily include electrical quantities such as voltage, current, and power, while non-electrical analog signals mainly involve measurements like pressure, temperature, flow rate, water level, oil level, as well as oscillation, vibration, and pulse signals.

2) The PLC collects and processes discrete signals. Discrete signals are categorized into interrupt-type and non-interrupt-type: Interrupt-type discrete signals include accident alarms, circuit breaker operations (opening and closing), and critical electromechanical protection action signals. Non-interrupt-type discrete signals refer to all other types of discrete signals, such as various fault indicators, position signals for circuit breakers and disconnect switches, operational status signals for unit equipment, and position signals indicating manual or automatic mode selection.

3) The power generation process is automatically controlled. The PLC can manage the start-up and shutdown of the hydropower generator units at the power station, collect data on power generation and phase-adjustment status, monitor the active and reactive power output of the generating units, and precisely regulate the opening and closing as well as the degree of the inlet gates. Additionally, it enables automatic monitoring of auxiliary equipment and more.

4) Automatically handle accidents. After the computer monitoring system is set up, the computer continuously monitors the hydropower station's equipment online, recording and storing various parameters of the operating units. Once an accident occurs, the computer analyzes the incident and then executes the corresponding accident-handling procedures, ensuring that the issue is addressed promptly. At the same time, the nature of the accident, as well as its time and location, are meticulously recorded.

5) Optimal power generation control. The most direct purpose of computer-based control in hydropower stations is to achieve optimal generation control. By adjusting the opening of turbine guide vanes according to the active power demand from the power system, the system precisely regulates the required water flow, ensuring the optimal coordination among generating units and the most efficient allocation of the overall load. This approach also guarantees the stable voltage quality at the hydropower station while maintaining a rational distribution of reactive power.

Information Security Protection Deployment for Hydropower Station Computer Monitoring System

• Deploy an industrial firewall in front of the LCU local control units within Security Zone I, leveraging deep parsing of industrial control protocols and an application protocol whitelist mechanism to ensure independent security for each LCU local control unit in Security Zone I.
• An industrial firewall is deployed between Security Zone I and Security Zone II, enabling robust information security protection and network isolation between the two zones with differing security levels through deep parsing of the OPC data acquisition protocol.
• Deploy a security monitoring and auditing platform in bypass within the Security Zone I, enabling real-time monitoring and recording of misoperations and various types of violations.
• Deploy Industrial Control Host Guardian on all operator stations, engineer stations, application servers, and database servers within the Security Zone I to prevent security risks caused by malicious software, human errors, and other potential threats.
• In Security Zone I and Security Zone II, an intrusion detection system is deployed in bypass mode to monitor and control viruses, trojans, and malicious attack activities within the large control area, thereby safeguarding industrial control equipment and systems from malicious code attacks.
• Deploying a unified security management platform within the production control zone to achieve centralized management and consolidated log analysis for industrial firewalls, monitoring and auditing platforms, and industrial control host guardians—thereby reducing operational complexity and enhancing the efficiency of security protection.

Project Application Cases

The independently developed and controllable monitoring system solution from Nanda Aotuo Hydropower Station has now been successfully deployed on-site at a major hydropower plant in China. Each generating unit at the hydropower station boasts an installed capacity of 200 MW, making this a medium-to-large-scale hydropower project. The introduction of Nanda Aotuo's solution marks a significant milestone for domestically developed, self-researched PLC products, which have already matched the functionality and performance levels of imported brands—and can fully meet the operational needs of China's hydropower automation and monitoring systems.

The following image shows a photo taken on-site: