1.Project Overview
A 30MW photovoltaic power station is located in a mountainous area. Due to the relatively weak local power grid structure and the great influence of light intensity and weather changes on photovoltaic power generation, there are frequent fluctuations in output power, low power factor, and harmonic pollution problems. These issues have a certain impact on the safe and stable operation of the power grid and also limit the power generation efficiency and economic benefits of the power station itself.
2.Application Scheme
To improve the power quality and meet the power grid connection requirements, the power station selected a set of 10kV static var generator devices with a rated capacity of 6Mvar. This device has multiple functions such as reactive power compensation, harmonic suppression, and active power support. It adopts advanced power electronic technologies and control algorithms and can quickly and accurately respond to the dynamic changes of the power grid and the photovoltaic power generation system.
3.Implementation Process
The static var generator device is installed on the 10kV booster station side of the photovoltaic power station, connected to the inverters and the power grid, and exchanges data with the monitoring system of the power station through a high-speed communication network to obtain parameters such as the power generation power of the photovoltaic array, grid voltage, and current in real time.
During the equipment installation and commissioning stage, the technical team optimized the control strategy of the static var generator. According to the characteristics of the local power grid and the operation requirements of the power station, appropriate reactive power compensation target values and voltage regulation ranges were set to ensure its efficient operation under different working conditions.
4.Application Results
Reactive Power Compensation and Power Factor Optimization: After the FDSVG was put into operation, the power factor of the power station was stably maintained above 0.99, effectively reducing the transmission loss of reactive power in the power grid and improving the transmission efficiency of the power grid. At the same time, it avoided the economic penalty due to non-compliance of the power factor, saving tens of thousands of yuan in electricity bills for the power station every month.
Voltage Stability and Power Quality Improvement: Through its rapid reactive power regulation ability, the FDSVG controls the grid voltage fluctuation range within ±2%. This significantly improves the voltage stability of the local power grid. When the light intensity changes rapidly, it can adjust the reactive output in time to prevent voltage sags or surges, ensuring the safe and stable operation of the power grid and in-station equipment. In addition, the harmonic suppression effect is remarkable, reducing the Total Harmonic Distortion (THD) to less than 3%, meeting the strict requirements of the power grid for harmonic content, reducing the damage to electrical equipment caused by harmonics, extending the service life of the equipment, and reducing the equipment maintenance cost.
Active Power Support and Power Generation Efficiency Improvement: When a fault occurs in the power grid or there is a voltage dip, the SVG can quickly provide active power support, helping the photovoltaic power station maintain a certain power generation capacity and avoiding large-scale power outages and power generation losses due to power grid faults. At the same time, by optimizing the power quality, the phenomenon of inverter disconnection from the grid and derating operation caused by voltage fluctuations and harmonic interference is reduced, improving the overall power generation efficiency of the photovoltaic power station. The annual power generation of the power station has increased by about 5%.
By applying the 10kV SVG device, the photovoltaic power station has successfully solved the power quality problems, improved its operational stability and economic benefits, and also enhanced its friendliness and adaptability to the power grid, providing strong technical support and practical experience for the efficient and reliable application of photovoltaic power generation in a complex power grid environment.