Voltage Variation Analysis

Utilities

A voltage variation analysis is used to determine the probability of nuisance tripping of sensitive electrical and electronic loads and to evaluate the effectiveness of possible corrective measures. In some cases a substation or circuit may be prone to generating voltage sags and momentary interruptions. Some commercial and industrial customers may use electrical and electronic equipment or may be operating processes too sensitive to these disturbances.

Voltage sags and momentary interruptions (see IEEE 1159-2009 for their definitions – the development of this standard was led by Electrotek Concepts) are the most frequently occurring typically non-destructive PQ disturbances on the utility grid and in customer facilities. Normal day-to-day grid operations can cause voltage sags & momentary interruptions to occur. However, the cycling of loads (ON and OFF) inside customer facilities can easily cause these disturbances resulting in the malfunction or shutdown of other loads too sensitive to these disturbances.

Electrical and electronic equipment are frequently too sensitive to voltage sags and momentary interruptions and trip offline in commercial facilities and industrial plants. These disturbances can easily cost commercial and industrial customers to lose thousands to millions to even billions of dollars in lost product, plant clean up costs, rework costs and delayed shipping penalties among other financial losses.

Electrotek expert engineers can conduct a voltage variation analysis to determine where these disturbances originate, why they occur and PQ mitigations to avoid them as well as mitigation methods to increase the immunity of critical equipment to these disturbances. Electrotek’s analysis also includes the economical analysis regarding the cost to purchase and maintain such PQ mitigation, comparison of various sag and momentary interruption mitigation technologies, engineering specifications for technology bids, engineering design for installation, production cost-benefit analysis and total turn-key project management. 

Architecture & Engineering Firms

A facility and plant power system and equipment owned / operated by commercial and industrial customers may be the design of an A&E firms. If customers suddenly start experiencing the tripping offline of electrical and electronic equipment, they may turn to their A&E firm for help. A&E firms are not likely to have the expertise to characterize, analyze, understand, identify and solve these power system and PQ problems. Having modeling / simulation software that can be used to study these problems doesn’t provide all the tools or expertise needed to address these PQ problems.

Electrotek’s expert engineers invite A&E firms and their customers to develop a working team relationship to properly and effectively address voltage sag and momentary interruption sensitivity issues occurring in commercial facilities and industrial plants. Electrotek’s PQView® PQ database library—largest in the world—allows our expert engineers to benchmark these PQ problems against the same and similar problems which have occurred on the same utility power system and geographical area as the problem at hand and compare these problems with the same and similar problems on other utility power systems, geographical locations and even in the same type of customers producing the same types of products.

Electrotek’s approach to addressing these problems can provide A&E firms with the required expertise to characterize, analyze, understand, identify and solve these power system and PQ problems for their customers. Electrotek’s PQ measurement monitoring systems from Dranetz Technologies combined with our PQView® PQ data management and analysis system allows utility and customer PQ data to be downloaded remotely from customer facilities and plants with any intervention from the utility or customer. Analyzed PQ data from customer facilities and plants can be served to the A&E firm’s project manager and to the customer at the click of a mouse.

Electrotek expert engineers can conduct a voltage variation analysis to determine where these disturbances originate, why they occur and PQ mitigations to avoid them as well as mitigation methods to increase the immunity of critical equipment to these disturbances. Electrotek’s analysis also includes the economical analysis regarding the cost to purchase and maintain such PQ mitigation, comparison of various sag and momentary interruption mitigation technologies, engineering specifications for technology bids, engineering design for installation, production cost-benefit analysis and total turn-key project management.

Equipment Manufacturers

Few electrical and electronic systems and equipment have sufficient PQ immunity to voltage sags and momentary interruptions. Although the PQ immunity of equipment including variable frequency drives (VFDs), computer and industrial power supplies, programmable logic controllers (PLCs) and electronic lighting devices among many others to common every day voltage sags and momentary interruptions has improved to some extent, many types of equipment are susceptible to these disturbances.

Complete systems used in commercial facilities and industrial plants made up of many individual devices and equipment still cannot ride-through common every day voltage sags and momentary interruptions. This results in the loss thousands to millions to even billions of dollars in lost product, plant clean up costs, rework costs and delayed shipping penalties among other financial losses. For example, a recently-constructed metal fabrications plant suffered several shutdowns of critical equipment in their steel making process which causes several hours of downtime and lost production. These shutdowns were caused by shallow voltage sags. The system controlling this process could not ride-through these minor sags. This deficiency in the PQ sag immunity of the process control system is a shortcoming in the equipment’s design on the part of the manufacturer.

Electrotek’s approach to addressing these problems can provide the equipment manufacturer with the required expertise to characterize, analyze, understand, identify and solve these power system and PQ problems for their customers. Electrotek’s PQ measurement monitoring systems from Dranetz Technologies combined with our PQView® PQ data management and analysis system allows utility and customer PQ data to be downloaded remotely from customer facilities and plants with any intervention from the utility or customer. Analyzed PQ data from customer facilities and plants can be served to the manufacturer and to the customer at the click of a mouse.

Electrotek expert engineers can conduct a voltage variation analysis to determine where these disturbances originate, why they occur and PQ mitigations to avoid them as well as mitigation methods to increase the immunity of critical equipment to these disturbances. Electrotek’s analysis also includes the economical analysis regarding the cost to purchase and maintain such PQ mitigation, comparison of various sag and momentary interruption mitigation technologies, engineering specifications for technology bids, engineering design for installation, production cost-benefit analysis and total turn-key project management.

End Users

Research and discussions with end users show that system and equipment malfunctions and failures caused by common every day voltage sags and momentary interruptions still occur frequently in commercial facilities and industrial plants. Customers experience thousands to millions of dollars in in lost product, plant clean up costs, rework costs and delayed shipping penalties among other financial losses. Many customers do not have specific or custom PQ mitigation systems and equipment to help them ride-through these PQ disturbances.

Most customers do not even monitor for power quality in their plant. Many that do own and operate PQ monitors do not know how to use them or are not using them to their fullest capability. Many customers that do have monitors permanently installed in their facilities and plants have monitors that do not record waveforms.

Most customers who experience malfunctions and shutdowns from voltage sags and momentary interruptions realize fairly quickly that they cannot endure similar PQ events, because of the lost product, plant clean up costs, rework costs and delayed shipping penalties among other financial losses that these disturbances typically cause.

Electrotek’s expert engineers can schedule an on-site PQ investigation to a customer’s facility or plant to conduct real-time voltage sag and momentary interruption testing. This unique testing is typically performed on the specific part of the facility equipment or plant process affected by the disturbances. If the customer is not sure which specific part is the weak link, Electrotek can conduct on-site testing to identify the weakest link. Testing can also be conducted on a single piece of equipment or on an entire assembly line, depending upon the electrical requirements of the process or line.

Electrotek engineers will also conduct a detailed technical review of each piece of process equipment or equipment used in an assembly line. Sometimes it is possible to determine the weak link(s) by Electrotek’s expert knowledge regarding which systems, equipment and devices are typically most sensitive to voltage sags and momentary interruptions. In any event, Electrotek can determine the weak links internal to a piece of equipment or within a process. Our expertise also includes determining the most appropriate PQ mitigation option for voltage sag and momentary interruption immunity problems.