Reactive Power Compensation Project for a Large Steel Plant 10kV Distribution System
Project Background
A large steel manufacturing group’s rolling mill workshop experienced a long-term power factor below 0.85 due to the high proportion of inductive loads such as electric arc furnaces and rolling mill motors. This resulted in significant reactive power losses, voltage fluctuations, and substantial power factor penalty charges. Frequent equipment start-up and shutdown operations also required the compensation system to have fast dynamic response and strong impact resistance.
Solution
Dongguan Electric's Containerized 10kV High-Voltage Automatic Reactive Power Compensation Device was directly connected to the workshop’s 10kV busbar. The system adopts a step-by-step capacitor switching strategy and is equipped with series reactors for harmonic suppression, allowing automatic adjustment of compensation capacity according to load variations.
Project Results
The power factor was consistently improved to above 0.95, reducing power factor penalty charges by over RMB 1 million annually while significantly decreasing reactive power losses and saving more than 500,000 kWh of electricity per year.
Voltage fluctuations caused by frequent motor start-up and shutdown were effectively suppressed, increasing busbar voltage compliance to 99.9% and preventing equipment downtime and product scrap caused by unstable voltage.
The containerized integrated design eliminated the need for a new electrical building. The system was commissioned simply through cable connection, significantly shortening the construction period and reducing civil engineering costs.
10kV Grid-Connected Reactive Power Compensation Project for a Utility-Scale Photovoltaic Power Plant
Project Background
A utility-scale photovoltaic power plant located in a mountainous area was connected to the grid at the 10kV voltage level. Due to inverter operating characteristics and line losses, the grid connection point frequently experienced voltage fluctuations and unstable power factor levels, making it difficult to meet utility grid compliance requirements. Additionally, the remote location posed challenges for operation and maintenance.
Solution
Dongguan Electric's Containerized 10kV High-Voltage Automatic Reactive Power Compensation Device was installed at the plant's booster substation. The system automatically adjusts compensation capacity based on grid connection voltage and reactive power demand, providing both capacitive and inductive compensation capabilities.
Project Results
Achieved dynamic power factor control, maintaining the grid connection point power factor between 0.95 and 1.0, fully meeting utility grid assessment standards and eliminating penalty charges.
Effectively mitigated voltage deviations caused by fluctuations in photovoltaic output, improving grid acceptance capacity and ensuring full delivery of generated electricity to the grid.
The fully enclosed containerized structure offers excellent protection against dust, moisture, and condensation, making it suitable for foggy and high-temperature-difference mountain environments. The equipment has operated fault-free for extended periods, significantly reducing maintenance workload.
Reactive Power Compensation Project for a Large Cement Production Line 10kV System
Project Background
A modern dry-process cement production line relied heavily on large motors such as kiln exhaust fans and ball mills. These loads generated significant reactive power impacts during start-up and operated with relatively low power factors, resulting in higher transformer loading and increased line losses. Harmonic interference within the plant also required effective harmonic suppression capabilities.
Solution
Dongguan Electric's 10kV High-Voltage Automatic Reactive Power Compensation Device was deployed with dedicated filtering reactors. The system utilizes a staged switching strategy that combines reactive power compensation and harmonic mitigation functions. The entire solution is integrated into a containerized enclosure installed within the plant's power distribution area.
Project Results
After compensation, the system power factor remained above 0.95, while transformer loading decreased by approximately 10%, reducing operating temperatures and extending transformer service life.
Harmonic currents were effectively suppressed, preventing damage to compensation capacitors and ensuring long-term stable operation. Annual equipment maintenance costs were reduced by approximately 30%.
The containerized design enabled direct on-site installation without extensive civil construction, making it ideal for plants with limited space and allowing rapid commissioning.
Urban 10kV Distribution Network Reactive Power Optimization Project
Project Background
An aging urban 10kV distribution network experienced long feeder distances, low voltage at line terminals, and concentrated inductive loads during peak residential electricity consumption periods. These conditions resulted in low power factors, increased line losses, and poor voltage compliance at the end-user level. The available space for network upgrades was also limited.
Solution
Dongguan Electric's Containerized 10kV High-Voltage Automatic Reactive Power Compensation Device was installed at intermediate nodes along the distribution feeders. The system automatically switches compensation capacity according to line voltage and reactive load conditions, enabling localized reactive power compensation.
Project Results
Terminal line voltage increased by approximately 5%, while voltage compliance improved from 92% to 99.5%, completely resolving low-voltage issues during peak consumption periods.
Reactive power losses along the feeder were reduced by approximately 40%, resulting in annual line loss reductions exceeding 100,000 kWh and significantly improving overall network efficiency.
The compact footprint allows installation directly on available land within the distribution area without constructing new electrical rooms. This makes the solution highly suitable for upgrading aging distribution networks with limited space while minimizing construction time and avoiding interruptions to customer power supply.
