China Electricity Regulatory Commission Reports Three Major Problems of Wind Turbine Exposure

The China Electricity Regulatory Commission informed that on February 24, Gansu Zhongdian Jiuquan Wind Power Co., Ltd. Bridge West first wind farm suffered a three-phase short-circuit due to a breakdown of the cable head due to a fault in the cable head, resulting in 10 wind farms including this wind farm. The 274 wind turbine units in the wind farm suffered from a series of reactions due to the lack of low-voltage ride-through capability and caused a series of reactions when the system voltage dropped. This resulted in 598 off-grid blowers in the accident, and the loss output accounted for wind power output in the Jiuquan area before the accident. 54.4 %, resulting in the frequency of the main grid of the Northwest Power Grid dropped from 50.034 Hz ​​before the accident to a minimum of 49.854 Hz.

On April 17th, Gansu Guazhou Xiehekou Wind Power Co., Ltd. Ganhekou West No.2 Wind Power Plant, a box-transformer high-voltage side cable breakdown, and a box-transform cable three-phase connection breakdown, causing a series of reactions, resulting in off-net wind power The unit reached 702 units, and the loss output accounted for 54.17% of the wind power output in the Jiuquan area before the accident, causing the frequency of the northwest grid main network to fall to 49.815 Hz from 50.036 Hz before the accident.

On April 17th, a lead wire of the No. 8 wind case transformer of Guojia Jiaxin Wind Farm in Zhangjiakou, Hebei Province was loosened to a short circuit, causing a series of reactions, causing 644 fans to be disconnected from the network, and loss of wind power output accounted for 48.5% of the wind power output in the Zhangjiakou region before the accident. As a result, the frequency of the main network of North China Power Grid dropped from 50.50 Hz before the accident to a minimum of 49.95 Hz.

The SERC believes that the above-mentioned three large-scale wind turbine decoupling incidents revealed four major safety issues in the current development of wind power:

First, in terms of equipment manufacturing, most of the wind turbines that have been put into operation do not have low-voltage ride-through capability, do not meet the technical requirements for access to the power system, and are easily removed from the grid if a fault occurs in the grid and the system voltage is reduced.

Second, there are many problems in the construction quality of wind farm construction. Some project owners do not have strict project quality management. The implementation of project quality inspection, inspection, control and acceptance systems is not in place; some construction unit construction quality management and supervision units supervise the construction quality of the project. Did not do well.

Third, in terms of access to wind farms, the research on the overall safety of large-scale wind farms connected to the power grid needs to be strengthened. Some grass-roots power grid enterprises have lax access to wind farms, and wind turbines are not put into operation to implement the low voltage specified in grid-connection agreements. Through the capability commitment, grid-connected wind farms have not been connected to grid operation through grid-connected safety assessment.

Fourth, in terms of wind farm operation, some wind farms have weaknesses in their operation and management, their safety management systems are not perfect, and the on-site operational procedures are not perfect. The importance of secondary systems and reactive power compensation devices is insufficient, and reactive power management and secondary system management are not. Satisfy the grid safety requirements; the power dispatching agencies have weak supervision and management of the secondary systems and reactive power compensation devices of wind farms; there is no verification of wind farm protection settings, and there is no effective supervision and management of wind farm reactive power compensation device configuration and parameter setting.

The SERC believes that these three accidents sounded the alarm for wind power safety supervision and management work. During the "Twelfth Five-Year Plan" period, China's wind power will continue to maintain rapid development. The impact of wind turbines on the safe operation of the power system needs to be highly valued.

To this end, the SERC issued the "Circular on Effectively Strengthening the Safety Management of Wind Farms to Effectively Prevent the Frequent Abandonment of Large-Scale Wind Turbine Accidents," and proposed that the wind turbine must have low-voltage ride-through capability. Six working requirements such as the establishment of a practical low-voltage ride-through capability improvement plan.

Li Yinghua, Deputy Director of the Bureau of Safety Supervision of the SERC, believes that it is not an easy task to carry out low-voltage traversing of wind turbines. Each unit will have a renovation fee of several tens of thousands of yuan, which will enable wind turbine equipment manufacturers and wind power project developers to invest in funds. Technical pressure. He also disclosed that a new national standard for wind power grid connection technology will be introduced in the first half of this year, requiring all grid-connected wind turbines to have low-voltage ride-through capability to further improve the safety of wind power grid integration.