Reactive Power Compensation in Impact Load Applications

November 18 , 2024

Reactive Power Compensation in Impact Load Applications

What are Impact Loads?

Impact loads are electrical devices that need a lot of power. They often use more than 30% of the transformer's capacity. These loads can change quickly and unpredictably. These loads can significantly affect power quality and stability, making their management a key challenge in modern power systems.

Characteristics of Impact Loads

Impact loads are common across various industries and can be categorized into three main types:

1. Inverter Welding Equipment

These cause current distortion, leading to fluctuating harmonic levels.

2. Frequent Start-Stop Motors

Equipment like punches, paper cutters, and grain carts experience rapid load changes, affecting both active and reactive power levels.

3. Arc Furnace Loads

These exhibit completely random, phase-uncorrelated load variations, making them particularly difficult to predict and manage.

Power Quality Issues Caused by Impact Loads

Impact loads can lead to several problems:

· Reactive Power Fluctuations: Increased losses and higher operational costs.

· Harmonics: Distorted waveforms that affect equipment performance.

· Voltage Fluctuations: Sudden changes causing instability.

· Three-Phase Imbalance: Increased system losses and inefficiencies.

Traditional compensation methods, such as capacitor banks, struggle to handle these rapid changes, leading to inefficiencies, equipment wear, and potential over compensation penalties.

A Modern Solution: SVG Technology for Impact Loads

Static Var Generators (SVG) offer a cutting-edge solution for reactive power compensation, especially for fast-changing impact loads. Using advanced IGBT-based technology, SVGs respond within 10ms, addressing rapid fluctuations efficiently.

In a hybrid SVG-capacitor system, SVG handles immediate, high-speed adjustments, while the capacitors provide bulk compensation. This synergy reduces switching frequency, extends capacitor life, and prevents issues like over compensation.

Example Configuration

For a 100 kVAR SVG paired with a 400 kVAR capacitor bank:

· Compensation Range: -100 kVAR (inductive) to +500 kVAR (capacitive).

· The SVG automatically adjusts reactive power. It fixes any excess or shortfall from the capacitors. This keeps a stable power factor.

For fast-impact loads, the SVG size should match the capacitor bank’s capacity to handle peak demands effectively. For example, a 400 kVAR capacitor bank needs a 400 kVAR SVG. This helps manage quick changes and stops over or under-compensation during load changes.

Wiring the Hybrid Compensation System

In hybrid systems, the current transformer (CT) for the SVG should be placed upstream of the capacitor bank. This ensures the SVG accurately compensates for any reactive power imbalance caused by the capacitor steps. The result is improved compensation performance and precise power factor correction at the grid metering point.

YT Electric is the biggest OEM manufacturer of low-voltage AHF and SVG with more than 15 years' experience. All products hold certifications for ISO9001, CE, and CQC standards; type test reports support them.

YT Electric’s Advanced Power Quality Solutions

Static Var Generator (SVG)

YT Electric's SVG offers accurate power factor correction. It also fixes three-phase imbalances and filters harmonics below the 25th order. It is particularly well-suited for photovoltaic systems and applications requiring quick reactive power compensation.

· Product Range:

· Rack-mounted or wall-mounted types: 10–150 kVAR

· Cabinet solutions: Up to 600 kVAR

Active Harmonic Filter (AHF)

YT Electric's AHF reduces harmonic distortions, ensuring improved equipment performance and system reliability. Along with its harmonic filtering abilities, it has all the functions of the SVG. This provides a complete solution for managing power quality.

· Product Range:

· Rack-mounted or wall-mounted types: 15A–200A

· Cabinet solutions: 50A–750A

With these products, YT Electric addresses complex power quality challenges, ensuring efficient and reliable solutions for various industrial and commercial applications. YT Electric designs its products for harmonic filtering, reactive power compensation, and load balancing.