Anke Electrical Co., Ltd.

As one of the clean energy sources, wind power capacity has seen rapid growth in recent years. On August 17th, the National Energy Administration released the statistics on the power industry in China for the period of January to July. As of the end of July, the cumulative installed power generation capacity nationwide reached approximately 2.74 billion kilowatts, with a year-on-year increase of 11.5%. Among them, the installed capacity of solar power generation was about 490 million kilowatts, with a year-on-year increase of 42.9%.Wind PowerThe installed capacity reached approximately 390 million kilowatts, a year-on-year increase of 14.3%. Wind farms are divided into onshore and offshore, typically located in remote areas with scattered installations and harsh environments. Therefore, a remote monitoring system is essential for the operation and maintenance personnel to manage the wind farms efficiently.

Electrical Equipment for Wind Power Plants

Each generator set is equipped with a turbine generator at the top of the canopy, featuring adjustable angle blades at the front. The system can adjust the tilt angle of the blades according to varying wind conditions. The blades typically rotate at 10-15 rpm, which can be adjusted through a transmission to reach 1500 rpm to drive the generator. Inside the canopy, an industrial PLC is also installed for control and data collection. The PLC gathers data on wind speed, direction, rotation speed, active and reactive power generation, and uses this data for real-time control of the generator. Onshore, at the bottom of the wind turbine tower, a transformer substation is set up for voltage boosting and collection. Depending on power and geographical conditions, multiple turbines can be stepped up in voltage and connected in parallel to the substation's low-voltage bus. Afterward, the voltage is further increased by the main transformer to 110kV or higher and then connected to the grid. The electrical connection diagram of the wind power generation plant is shown in Figure 1. The voltage generated by the wind turbines is generally 0.69kV, stepped up to 10kV or 35kV by the transformer substation, and then connected to the grid after being stepped up again to 110kV or higher voltage levels.

Unlike onshore wind power, offshore wind turbines, due to harsh environmental conditions (high humidity, high salt density), integrate the dry-type transformer for primary voltage increase within the nacelle. This not only resolves the issue of land area occupation for the entire unit but also avoids the difficulties in protection brought by installing the transformer at a lower position.

Wind Farm Protection and Monitoring Equipment

The wind power generation process involves the wind turbines generating electricity, which is then stepped up by the transformer substation, collected, and stepped up again at the substation's medium-voltage busbar, before being transformed by the main transformer to the substation's high-voltage busbar and finally connected to the power grid through high-voltage lines. This process requires two voltage boosts before being integrated into the grid. There are numerous types of electrical equipment involved, and any fault in any stage can disrupt the normal operation of the wind farm. Therefore, protection and monitoring devices must be set up at all stages of the wind farm to monitor its operational status.

Box Transformer Measurement and Control Device

At onshore wind farms, to reduce line losses, an 0.69/35(10)kV transformer substation is typically installed near the wind turbines. With wind turbines spaced hundreds of meters apart and located far from the control room, the transformers are situated in open fields with harsh natural conditions, making manual inspections inconvenient. This makes the measurement and control of the transformer substation a challenging aspect of wind farm monitoring. The transformer substation measurement and control device is a crucial part of the wind farm monitoring system, enabling intelligent management of the transformer. This device can protect and remotely monitor the wind turbine transformer, achieving functions such as "telemetry, telecontrol, teleprotection, and teleadjustment," significantly enhancing the operational and maintenance efficiency of wind farms.

Low-voltage line and bus protection measurement and control

Multiple wind turbines, after being stepped up to 35(10)kV in a single boost, are paralleled into a circuit for connection to the step-up substation's low-voltage busbar. When there are a large number of wind turbines in the wind farm, the lines feeding into the low-voltage busbar of the step-up substation also increase in number. To enable monitoring, the lines are equipped with line protection devices, multi-functional measurement and control instruments, power quality monitoring devices, and wireless temperature measurement devices, ensuring real-time monitoring of electrical protection, measurements, and temperatures. Arc protection devices are set up on the low-voltage busbar.

Primary Transformer Protection and Control

The wind turbine generators step up the voltage to 110kV after being converged on the low-voltage busbar and then fed into the power grid through the main transformer. The main transformer is equipped with differential protection, high-reserve protection, low-reserve protection, non-electrical protection, measurement and control devices, transformer temperature control, and position transmitters, which collectively provide protection and measurement functions for the main transformer, all installed in a centralized control panel.

Table 2: Main Transformer Protection and Control Configuration

High-voltage Line Protection and Control

The electrical power generated by the wind farm is stepped up to 110kV twice before being connected to the grid. The 110kV lines are equipped with fiber-optic differential protection, distance protection, anti-islanding protection, and measurement and control devices.

Table 3: 110kV Line Protection and Control Configuration

Wind Farm Monitoring System

The wind farm monitoring platform achieves real-time monitoring, control, and management of the operational status and wind turbine data, enhancing the reliability and operational efficiency of wind farms, reducing maintenance costs, and realizing intelligent management.

The wind power generation plant covers a large area with scattered equipment, demanding high reliability and real-time performance in data communication. Under favorable conditions, an optical fiber redundant ring network can be used for data collection and communication, or LORA wireless transmission can be adopted for data transfer.

The PLC and transformer substation control devices for the fan unit transmit data to the control room's data server via an optical fiber ring network. The data from the comprehensive automation system of the substation is uploaded to the data server via Ethernet. Multi-functional meters, wireless temperature measurement devices, temperature transmitters, gear position transmitters, DC systems, and other intelligent devices connect to the communication management unit to upload data to the server.

Wind Farm Monitoring

A comprehensive display of the fundamental parameters of wind turbines within the entire wind farm (including wind speed, power, and rotation speed), with the capability to remotely control the start and stop of individual or multiple turbines. This enables monitoring of each turbine's daily, monthly, and annual electricity generation, facilitating real-time supervision of the turbines' operational status.

Aircraft Monitoring

Monitoring of parameters and control states for various control modules within the system, including: variable pitch, yaw, gearbox, generator, hydraulic station, engine room, inverter, power grid, safety chain, torque, main shaft, tower foundation, anemometer, etc. Comprehensive display of parameters, faults, and trend charts for each module.

Real-time data is displayed.

Wind turbines and substation equipment within the wind farm are equipped with sensors and monitoring devices, enabling real-time collection of operational electrical data, temperature, vibration, and other parameters, with timely alerts for anomalies.

Power Management

The display of active and reactive parameters, along with the control and adjustment of active and reactive power, effectively reduces the operation costs of enterprises, providing data support for achieving energy conservation and emission reduction goals.

Production Report

The news report features the display of key parameters such as wind power generation, wind farm performance indicators, and unit energy, supporting the statistical analysis of the operation status of wind farm equipment across different time dimensions (daily, monthly, annual). It allows for categorized and itemized statistics of important parameters on a daily, monthly, or annual basis, and generates corresponding reports.

Statistical Analysis

Our platform supports a variety of statistical analysis functions, fully tapping into the potential value of data. We offer energy-saving optimization solutions, providing decision-making support for managers, and effectively enhancing the management level of enterprises. Additionally, we aim to achieve the goals of energy conservation and emission reduction, as well as scientific production. Analysis methods include: fault statistics, power curve, availability statistics, wind rose diagram, wind speed and power reports, monthly and daily utilization rates, and downtime statistics, etc.