Increasing capacity, achieving savings, and no reactive power costs at Nijsen

The Challenge

Nijsen has been working on more sustainable animal feed production every day for over 30 years. The family business in Veulen, Limburg, turns food industry waste streams into animal feed via its own chains. Electrical installations at Nijsen use a relatively large amount of reactive power: energy which is supplied to the installation, but not absorbed. This energy places a burden the grid and the transformer, creating a real possibility of higher energy bills, reactive power penalties and reduced transformer capacity. Real power – energy that is actually absorbed and used to perform work – together with reactive power, form the total, or apparent power of an installation.

“Nijsen has two production facilities at the same location,” says Joost Giesbers, Engineer at HyTEPS. “Both have their own transformer and main power supply. A sizeable solar farm, which also has its own connection, will be added to that. To avoid penalties, Nijsen wanted to reduce the reactive power. This is achoeved by improving the Cosinus Phi.”

Goal

• Improve Power Factor, making the electrical system work more efficiently.
• Detect causes and propose solutions
• Ensure optimal power factor under various operating conditions
• Prevent excessive reactive power

Solution

The Power Factor (PF) in an electrical system indicates how effectively electrical power is used. A Power Factor of 1 means that 100% of the electrical power is effectively used to perform useful work. To achieve a higher Power Factor at Nijsen, reactive power needed to be reduced.

Commissioned by Nijsen, HyTEPS began measuring and analyzing in consultation with Fudura. We advised placement of two capacitor banks to compensate inductive power in the installation with capacitive power. Capacitors store electrical energy in an electrical field. They can cause a phase shift opposite to that caused by inductive loads which allows capacitors to neutralize reactive power generated by inductive loads. This eliminates the need for reactive power to be supplied from the mains and will significantly reduce the apparent power through the main supply. As a result, RMS current through the main power supply will also decrease.

Results

After commissioning of the capacitor banks on two different main distribution boards, reactive power was soon significantly reduced. This results in a lower load on the transformer. In the meantime, Nijsen no longer needs to pay reactive power penalties.

The capacitor bank actively measures how much reactive power is being absorbed and regulates itself to continuously meet this demand.

On one main distribution board, total RMS current was reduced from approximately 1150 A to 900 A. With the capacitor bank in automatic mode, the PF improved from 0.76 to 0.96. On the other main distributor, total RMS current was reduced from approximately 1350 A to 950 A. With the capacitor bank in automatic mode, PF improved from 0.79 to 0.96. THDu in both installations remains below the recommended 4% limit throughout the measurement.

Joost: “Based on measurement data, we could conclude that the capacitor bank improved the Power Factor by up to 20% when switching on successive steps. In addition to eliminating reactive power costs, this RMS current reduction also frees up installation capacity on the supplying transformers. Joint savings on the two transformers (250 + 300 Amps) yield 550 Amps.”

The table shows how effective the operation of the capacitor bank is on reactive power and how this reduces the RMS current in the installation. Please note, during these measurements load in the installation changes so results may vary from step to step. The plant isn’t even running close to full power – if expanded the bank can easily keep up – there is still 150 kVAR left!

Through ‘inspansion’, capacity can be created behind transformer(s) in electrical installations. In this way, greater performance can be obtained from existing systems in a safe, smart, sustainable way. This is particularly interesting for any parties that requires more capacity, but is facing the limits of the power grid, for example.

“Good Power Quality is crucial for customers’ continuity as well as sustainable deployment of our assets,” says Ulas Köse, Infra Services Product Manager, Fudura. “Reactive power is a clear example of an area in which we can help, as the work at Nijsen demonstrates. Based on data we collect as a recognized metering company, we can immediately determine where issues are being caused. By measuring Power Quality in greater detail with the experts from HyTEPS, we can provide cost-efficient and effective customized solutions.”

“This is a win-win situation: customers achieve an efficient installation and savings, while we can offer customers the highest possible levels of energy security.”