Power quality and food waste

Fixing power quality, from the grid, can reduce food waste in an increasingly autonomous and continuous production cycle, explains Darcy Simonis, Vice President of ABB’s Food and Beverage segment.

Food is delicate, so even slight power disruptions can lead to food wastage. Disruption of machines in food production and refrigeration can lead to food being burnt, spoiled or contaminated. Due to stringent health and safety regulations, this food must then be discarded. This can escalate fast in a continuous production system because if even one piece of equipment goes out of sync, and is not caught quickly, large quantities of products will go to waste.

Low power quality is when power supplies are disrupted and no longer power machinery properly, such as voltage drops. These are sudden increases in current that cause voltage to drop over the impedance of a supply network, causing the voltage to vary. Disruptions from low power quality can cause machinery to shut down in an unsafe manner.

For example, if a conveyor was to break down while feeding bread through an oven, it could lead to the loaves igniting, which would not only cause severe damage to the conveyor belt and oven, but the fire could then spread putting the whole plant at risk. Improper shutdowns for smart machines can also damage internal systems, scrambling the data and leading to faults and loss of precision.

The effects of power disruptions are also financial. The Pan-European Power Quality Survey reports that annual losses from power quality issues may amount to 4% of business turnover. This is set to grow as more processes become automated leading to power disruptions having larger effects on operations.

Food manufacturers understand that reducing food waste is a key method for creating a strong operation. The main way to reduce food waste is to have good control over processes. However, modern methods of increasing control through software and improved monitoring cannot have the desired effect if they are damaged through grid disruptions. As such, plant power quality should be closely monitored to prevent any unexpected interruptions.

Protecting systems

Research shows that over 90% of power quality issues that lead to industrial equipment malfunctions are voltage sags. These happen when the RMS voltage decreases between 10 and 90% of nominal voltage for up to one minute. Voltage sags are generally caused by weather events such as high winds, heavy rain or snow build-up, but can also be triggered by traffic accidents and construction works. These sags can cause short circuits and overloads.

Businesses, sadly, cannot influence the weather or external works and must rely on other methods to protect equipment. Active voltage conditioners, such as ABB’s PCS100 AVC range, can sense power disruptions, such as voltage sags, and perform corrective measures returning the voltage to nominal levels. This will allow for undisrupted production reducing unwanted downtime and eradicating food wastage caused by system faults.

If an unprotected bottling plant for soft drinks was hit by power disruptions this could cause large losses through, for example, misalignment of injector and bottles. Formulas for soft drinks are also very delicate and loss of precision could mean that ingredient amounts could become skewed altering the taste of the product. By installing active voltage conditioners plant managers can ensure the delicate processes are protected.

As food and beverage production becomes a 24-hour process, manufacturers need to take greater precautions to ensure both their equipment and staff remain safe while reducing food waste.