Smart Monitoring System for Wind Farms: Design & Implementation

1.Background

Wind power generation converts the kinetic energy of wind into mechanical energy, and then transforms that mechanical energy into electrical energy—this is wind power generation.
The principle of wind power generation involves using wind to rotate wind turbine blades, which then drive a gearbox to increase rotational speed, thereby driving the generator to produce electricity.

Under China’s growing energy demands, wind power generation continues to expand, and wind farm construction is intensifying. A single power company may operate multiple wind farms, which are often distributed across different geographical regions. Additionally, depending on their scale, individual wind farms may consist of dozens to hundreds of wind turbines. Due to these conditions, each wind farm is equipped with its own power monitoring system. However, centralized management of multiple wind farms presents significant challenges. To address this issue, the establishment of centralized control centers (Central Control Centers) provides an effective solution.

As a result, while networking and intelligence in wind farms improve production and management efficiency, they also create new attack vectors for malicious actors. In recent years, cybersecurity incidents in the power sector have occurred frequently, exposing the electricity industry to increasing security threats and challenges.

2. Wind Turbine Control System

A fully automatic control system is required for the operation and protection of wind turbines. This system must be capable of automatically starting the turbine, controlling the mechanical pitch adjustment mechanism of the blades, and safely shutting down the turbine under both normal and abnormal conditions. In addition to control functions, the system also performs monitoring tasks—providing information such as operational status, wind speed, and wind direction.

The wind turbine control system consists of three main components:

• Tower Base Main Control Cabinet

• Nacelle Control Cabinet

• Hub Control Cabinet

The Wind Power Control Unit (WPCU) serves as the core controller for each turbine and is distributed within the tower and nacelle of the turbine.

2.1 Tower Base Control Station

The tower base control station—also known as the main control cabinet—is the core of wind turbine control, primarily consisting of a controller and I/O modules. The controller uses a 32-bit processor, and the system runs on a strong real-time operating system. It executes complex main control logic and communicates in real time with the nacelle control cabinet, pitch system, and converter system via fieldbus, ensuring the turbine operates under optimal conditions.

The tower base cabinet includes:

• PLC master station

• RTU (Remote Terminal Unit)

• Industrial Ethernet switch

• UPS power supply

• Touchscreen (for local monitoring and operation)

• Push buttons, indicator lights, miniature circuit breakers, relays

• Heating elements, fans

• Terminal blocks

2.2 Nacelle Control Station

The nacelle control station collects sensor signals from the turbine, including temperature, pressure, rotational speed, and environmental parameters. It communicates with the main control station via fieldbus. The main controller uses the nacelle control rack to manage yawing and cable untwisting functions. Additionally, it controls auxiliary motors, oil pumps, and cooling fans within the nacelle to maintain optimal turbine performance.

The nacelle control cabinet consists of:

• Nacelle PLC station

• Power supply module

• FASTBUS slave module

• CANBUS master module

• Ethernet module (for local PC maintenance access)

• Digital and analog I/O (DIO, AIO) modules

• Circuit breakers, relays, switches

2.3 Pitch Control System

Large-scale wind turbines (above 1 MW) typically employ either hydraulic or electric pitch systems. The pitch system uses a front-end controller to regulate the pitch actuators of the three turbine blades. As an execution unit of the main controller, it communicates via CANopen to adjust blade pitch angles for optimal performance.

The pitch system includes a backup power supply and a safety chain to ensure emergency shutdown under critical conditions.

The hub control cabinet includes:

• Hub PLC station

• Servo drive units

• Emergency pitch battery and monitoring unit

• Emergency pitch module

• Overspeed protection relay

• Miniature circuit breakers, relays, terminal blocks

• Push buttons, indicator lights, and maintenance switches

2.4 Backup Emergency Safety Chain System

The backup emergency safety chain is a hardware-based protection mechanism independent of the computer control system. Even if the control system fails, the safety chain remains functional. It connects critical fault conditions—those that could cause catastrophic damage to the wind turbine—into a single series circuit. When triggered, the safety chain initiates an emergency shutdown, disconnecting the turbine from the grid, thereby maximizing protection of the entire system.

3. System Architecture and Functional Overview

The wind farm power monitoring system comprises the following key components:

• Local Wind Turbine Control Units (WPCUs)

• High-speed redundant ring fiber-optic Ethernet network

• Remote upper-level operator stations

The local wind turbine control unit is the core controller for each turbine, responsible for parameter monitoring, automatic power generation control, and equipment protection. Each turbine is equipped with a local HMI (Human-Machine Interface) for on-site operation, commissioning, and maintenance.

The high-speed redundant ring fiber-optic Ethernet serves as the system’s data highway, transmitting real-time turbine data to the upper-level monitoring system.

The upper-level operator station is the operational monitoring center of the wind farm. It provides comprehensive turbine status monitoring, parameter alarms, and real-time/history data logging and display. Operators can monitor and control all turbines from the central control room.

3.1 Field Control Layer

The field control layer consists of the following key components:

• Tower base main control cabinet

• Nacelle control cabinet

• Pitch control system

• Converter system

• Local HMI (Human-Machine Interface) station

• Industrial Ethernet switch

• Fieldbus communication network

• UPS power supply

• Emergency shutdown backup system

The Wind Turbine Control Unit (WPCU) at the field level serves as the core controller for each wind turbine. It is responsible for real-time parameter monitoring, automatic power generation control, and equipment protection. Each turbine is equipped with a local HMI interface that enables on-site operation, commissioning, debugging, and maintenance.

3.2 Central Monitoring Layer

The central monitoring layer is the operational core of the wind farm, providing comprehensive monitoring of turbine status, parameter alarms, and real-time/history data logging and display. Operators can monitor and control all turbines from the central control room.

This layer also enables supervision and control of key subsystems, including:

• Hydraulic system

• Meteorological system

• Electric pitch control system

• Gearbox system

• Yaw system and yaw control

Through integrated SCADA functionality, the central monitoring layer ensures efficient, safe, and reliable operation of the entire wind farm.