Wind farm centralized monitoring system solutions

 

As one of the clean energy sources, the installed capacity of wind farms has increased rapidly in recent years. On August 17, the National Energy Administration released the statistics of the national power industry from January to July. By the end of July, the country's cumulative installed power generation capacity was about 2.74 billion kilowatts, an increase of 11.5% year-on-year. Among them, the installed solar power capacity of about 490 million kilowatts, an increase of 42.9%; The installed capacity of wind power was about 390 million kilowatts, up 14.3 percent year on year. Wind farms are divided into onshore wind power and offshore wind power, which are generally remote, dispersed installation and harsh environment. Therefore, wind farms need a set of remote monitoring system to facilitate operation and maintenance personnel to manage wind farm operation more efficiently.

 

01 Electrical equipment for wind farms

The top bin of each generator set is equipped with a turbine generator, the front is adjustable Angle of the wind blade, the system can adjust the tilt Angle of the wind blade according to different wind conditions, the general speed of the wind blade is 10 ~ 15 RPM, through the gearbox can be adjusted to 1500 RPM to drive the generator. At the same time, an industrial PLC is also configured in the bin for control and related data collection, through the PLC to collect wind speed, wind direction, speed, active power and reactive power and other related data, and through the collected data for real-time control of the generator. On land, a box transformer is also set at the bottom of the fan tower, which is responsible for voltage boost and converging. According to the power and geographical conditions, multiple fans are connected to the booster substation in parallel after a voltage boost. After further increasing the voltage through the booster transformer, they are integrated into the large power grid to transmit electric energy for the power grid. The electrical wiring diagram of the wind farm is shown in Figure 1. The voltage emitted by the fan is generally 0.69kV, and the boost voltage is 10kV or 35kV after the box conversion, multiple parallel conjunctions are connected to the low-voltage bus bar of the boost substation, and then the main transformer is boosted to 110kV or higher voltage level before being connected to the power grid.

Unlike onshore wind power, due to the harsh environment (high humidity, high salt density), the dry transformer used for a single boost is integrated in the fan bin, which not only solves the problem of the floor area of the entire unit, but also avoids the difficult problem of protection caused by installing the transformer at a lower position.

 

FIG. 1 Schematic diagram of electrical wiring of wind farm

 

 

02  Wind farm protection and measurement and control equipment

Wind farms from the fan power generation - booster box transformer - busbar - booster station - main transformer - booster station high voltage busbar - high voltage outlet - grid connection, in the middle need to go through two booster after the grid, the number and type of electrical equipment is more, any link failure will affect the normal operation of the wind farm. Therefore, it is necessary to set up protection and measurement and control devices in each link of the wind farm to comprehensively monitor the operating status of the wind farm. FIG. 2 shows the configuration diagram of the protection and measurement and control device of the wind farm.

 

 

FIG. 2 Configuration diagram of wind farm protection measurement and control device

 

2.1 Box change measurement and control device

In order to reduce line losses in onshore wind farms, a 0.69/35(10)kV box booster station is generally installed next to the fan. The distance between the wind farm fans is hundreds of meters, far away from the central control room; The boost voltage changes are all in the open field, the natural environment is harsh, it is not convenient for manual inspection, which makes the measurement and control of the box change become the monitoring difficulty of the wind farm. The measurement and control device of tank variation is the core part of the wind farm monitoring system, which realizes the intelligent management of tank variation. The box variation measurement and control device can protect and remotely monitor the wind power box variation, and fully realize the functions of "remote communication, telemetry, remote control and remote adjustment", which greatly improves the operation and maintenance efficiency of the wind farm.

 

FIG. 3 Measurement and control device of box variation in wind farm

 

AM6-PWC box transformer protection measurement and control device is an integrated protection, measurement and control, and communication device for different requirements of wind power and photovoltaic voltage boost. Its functional configuration is shown in the following table.

 

 

2.2 Measurement and control of low-voltage line and bus protection

After the first boost of 35(10)kV, multiple fans are connected to the low-voltage bus of the boost substation in a parallel loop. When there are more fans in the wind farm, there are more lines that are connected to the low-voltage bus of the boost substation. In order to achieve comprehensive monitoring, the line is equipped with line protection device, multifunctional measurement and control instrument, power quality monitoring device, wireless temperature measurement device, to achieve real-time monitoring of line electrical protection, measurement and temperature, low voltage side bus arc protection device.

 

Table 1 Low voltage side line, bus protection measurement and control configuration

 

2.3 Main transformer protection measurement and control

The fan generation is merged into the power grid after the main transformer boosts the voltage to 110kV after the busbar converging on the low voltage side. The main transformer is equipped with differential protection, high backup protection, low backup protection, non-power protection, measurement and control device and transformer temperature control, gear transmitter, to realize the protection and control function of the main transformer, and centralized panel installation.

 

Table 2 Main transformer protection measurement and control configuration

 

2.4 High voltage line protection measurement and control

The electric energy emitted by the wind farm is merged into the power grid after being boosted to 110kV twice, and the 110kV line is equipped with optical fiber longitudinal difference protection, distance protection, anti-island protection, measurement and control devices.

 

Table 3 110kV line protection measurement and control configuration

 

 

03  Wind farm monitoring system

The wind farm monitoring platform can monitor, control and manage the real-time data of the wind farm and the wind farm, improve the reliability and operation efficiency of the wind farm, reduce maintenance costs, and realize intelligent management.

The wind farm covers a large area, the equipment is scattered, and the system requires high reliability and real-time data communication. When the conditions are available, the data acquisition and communication can be carried out by optical fiber redundant ring network, and the data transmission can also be carried out by LORA wireless mode.

 

FIG. 4 Wind farm monitoring system diagram

 

The data of the PLC and box transformer measurement and control device of the fan unit are transmitted to the data server of the control room through the optical fiber ring network, the data of the integrated automation system of the booster station is uploaded to the data server through the Ethernet, and the multi-function instrument, wireless temperature measurement, temperature transmitter, gear transmitter, DC system and other intelligent devices are connected to the data transfer server of the communication management machine, as shown in Figure 4.

 

Figure 5 Wind farm monitoring interface

 

3.1 Wind field monitoring

The basic parameters (including wind speed, power, speed, etc.) of the whole wind farm fan can be comprehensively displayed, and the daily, monthly and annual power generation of each fan can be monitored by remote control of the start and stop of a single or multiple fans, so as to facilitate real-time monitoring of the operation of the fan.

 

3.2 Unit Monitoring

Monitor the parameters and control status of each control module in the unit, including: variable pitch, yaw, gear box, generator, hydraulic station, engine room, converter, power grid, safety chain, torque, spindle, base, wind meter, etc. To realize the comprehensive display of parameters, faults and trend charts of each module.

 

3.3 Real-time Data display

The wind farm fans, substations and other equipment are equipped with sensors and monitoring equipment, which can collect the operating electrical data, temperature, vibration and other parameters of the equipment in real time, and give timely warning when abnormal.

 

3.4 Power Management

The display of active and reactive power parameters, the control and adjustment of active and reactive power and other functions can effectively reduce the operating costs of enterprises and provide data support for achieving the goal of energy conservation and emission reduction.

 

3.5 Production Report

Display and report important parameters such as wind power, wind field performance indicators, and unit new energy, and support statistics on the operation of each wind farm equipment by time dimension (day, month, year). This section describes how to collect statistics on important parameters by day, month, and year and generate reports.

 

3.6 Statistical Analysis

Support a variety of statistical analysis functions, fully tap the potential value of data, provide energy-saving optimization programs, provide decision-making basis for managers, practical and feasible to improve the management level of enterprises, and ultimately achieve the goal of energy conservation and emission reduction, scientific production. Analysis methods include: fault statistics, power curve, available utilization statistics, wind rose chart, wind speed power report, monthly and daily utilization rate and downtime statistics.