7/31/2015

Delta Power Quality Solution Delivers Reliable, Eco-friendly System for Rubber Tyred Gantry Cranes

Among different types of gantry cranes, Rubber Tyred Gantry (RTG) cranes feature many advantages such as mobility, flexibility and a relatively low cost. RTG cranes are widely used in many harbors. Recently, with the global trend toward eco-friendliness, electric RTG cranes that have replaced their traditional diesel engine with an electric power engine for oil saving and CO2 emission reduction, have become more and more popular. Many RTG cranes are adopting a power quality solution for their systems for better efficiency and energy-saving results.

Delta Industrial Automation provides a customized power quality solution that has been successfully applied to one harbor RTG system in China. This power quality solution includes a Delta Active Front End, AFE2000 series that effectively enhances system efficiency, improves power factor, and regenerates power from the system to the grid to reduce power consumption. In response to challenging weather conditions at the harbor, Delta also designed a special highly reliable box for the power quality units. The box is made with SUS304 stainless steel, has adopted IP65 high seal level waterproofing and is equipped with lightening protection units. The customized box also integrates several functions such as system control, AFE multi-function output, industrial air conditioning, and highly efficient thermal management.

The Delta power quality solution can connect in parallel to the original system without affecting daily system operations. During RTG crane system operation, the AFE2000 Series detects and transforms heat generated into power, conducts reactive power compensation and then returns the regenerated power to the grid system for reuse.

The outstanding performance of Delta's power quality solution is shown with actual operation results below:

- Lower Power Consumption: The original system consumed 196KW for material lifting and 12KW for material lowering. After adopting the Delta AFE2000 series, the system took 202KW for material lifting, and regenerated 133KW power from material lowering. The energy saving ratio may be up to 70% in the material lowering stage.

- Improved Power Factor (PF): In the original system, PF numbers for the material lifting and lowering stages were 0.92 and 0.55, respectively. The PF number for a system adopting Delta's AEF2000 series is 0.97 on average for both the material lifting and lowering stages.

- Saved Electricity Cost: Tests using the same operating conditions running the material handling process 10 times were performed for both systems. The total electricity consumption for the old and new systems with Delta's AFE2000 series was 25.62KWh and 10.79KWh, respectively. The results present an average 1.48KWh power saving for each material handling process. This could equal up to 77,000KWh electricity savings annually for a normal harbor crane helping users save electricity costs.

- Easy Maintenance: In the original system, regenerated power needs to be consumed and transformed to heat by a resistance box. This will shorten the lifetime of surrounding power lines and the resistors. The Delta AFE2000 series is able to provide more than 95% power regeneration efficiency. It is easy to maintain, and the product lifetime may be up to 10 years.

News Source:Industrial Automation Business Group