In the steelmaking process of an Electric Arc Furnace (EAF), heat is generated by electric arcs between the electrodes and the steel or iron materials inside the furnace. This intense energy melts the scrap and heats the molten steel. However, the arc striking process causes sudden surges that impact the transformer and upstream power grid. These fluctuations generate high-order harmonics and reduce the power factor of the grid, affecting overall power quality and system stability.
To address these issues, installing a power compensation device has become a key solution to protect the power grid and enhance power supply quality.
Types of Power Compensation Devices
Power compensation systems generally fall into two categories: Static Compensation and Dynamic Compensation.
Static Compensation
Static compensation refers to a type of reactive power compensation where the harmonic compensation parameters remain unchanged during furnace operation. It uses fixed capacitor or reactor banks, which are configured to target the specific harmonics most commonly generated during steelmaking processes.
There are two typical approaches:
- Fixed installation based on known harmonic content during melting;
- Selective configuration that engages different compensation units for different melting stages.
This method is widely applied in EAF power systems due to its simplicity and reliability. It is easier to operate and maintain compared to dynamic systems.
Dynamic Compensation
Dynamic compensation, on the other hand, is a real-time solution that adjusts its response based on varying harmonic content in the power network during different furnace operation stages. It automatically calculates and distributes the appropriate compensation ratio to match dynamic load conditions.
Though highly effective in improving power quality and increasing the power factor, dynamic compensation systems are more complex and expensive. As such, they are less commonly used but offer excellent performance where grid stability is critical.
What Is an SVC?
SVC stands for Static Var Compensator, a high-efficiency energy-saving technology that combines thyristor-controlled power electronics with automated digital control systems. An SVC typically consists of a thyristor-controlled reactor (TCR) and a capacitor bank working in parallel.
SVC provides rapid, dynamic, smooth, positive and negative reactive power reactive power compensation to:
- Improve power factor
- Enhance power quality
- Track and offset varying loads in real time
- Reduce reactive power flow and its associated losses
- Lower transmission voltage drop and resistive heating losses
- Suppress voltage flicker and harmonic distortion
