Maintaining a reliable supply of electricity is an absolute requirement for production of the goods and services that fuel our economy, yet it is often one of the most difficult problems faced by facility managers. The requirement to improve productivity is forcing many facility managers into the difficult dilemma of how best to balance the need for reliability with the demand to reduce costs for energy-hungry profit centers. Unfortunately, confusion over deregulation threatens to further erode energy reliability despite the fact that North American industry incurs billions of dollars annually in loses as a direct consequence of power interruptions, voltage sags or other power quality problems.
The increased use of sensitive electronic equipment, with its stringent input power requirements, has forced companies to place greater emphasis on the quality and reliability of their energy supply. Ironically, much of this emphasis has been directed towards costly solutions that place the primary responsibility for power quality and reliability on local electric utilities. While electric utilities continually strive to improve the quality and reliability of their energy delivery, the requirements for maintaining a reliable and cost-effective distribution system often conflict with the specific power quality requirements of a particular application or customer. The resulting solution is often an unsatisfactory compromise for both the utility and the user.
Fortunately, innovative solutions are emerging which enable facility managers to find the delicate balance between reliability and cost, ensuring that vital energy supplies are available to maintain critical operations. The broad range of technologies available within today’s market, including flywheels, batteries, capacitors, harmonic filters and active power conditioners to name a few, greatly enhance the possibility of finding a costeffective solution for most power quality problems. An added benefit often overlooked by those focusing on the new generation of "critical" applications is that many of these same advancements can also improve the productivity of common industrial processes, which have historically been referred to as “less sensitive” although no less critical to overall productivity.
Investigating Power Quality Problems
Investigation of any power quality or reliability problem should involve a thorough review of the critical load’s function and power requirements, along with the operation of the electrical supply. A thorough analysis at the point of use may reveal that a defective load or improper application is the problem, saving a great deal of time and energy in finding a solution. An outward approach will assist the investigator in determining the critical point in the distribution system at which it is most cost effective to implement a solution.
Many electric utilities offer services which can assist with these investigations, however it is important to recognize that power quality problems experienced by customers often originate within their own facility and not the utility supply. Initiating an investigation under the premise that the utility source is the cause of the problem may cause investigators to provide an incorrect diagnosis, leading to a broad-based solution that greatly increases the cost of implementation.
The increased demand for these types of investigative services has resulted in the proliferation of high-speed diagnostic equipment with enhanced capabilities for capturing and recording intermittent or high-speed power quality events. When combined with the experience of a competent power quality professional, these instruments provide a wealth of information that can be used to diagnose power quality problems, evaluate power requirements, verify equipment performance and specify appropriate solutions.
PQ Investigations
PQ Solutions
The importance of using an experienced power quality professional to evaluate the data collected with diagnostic equipment cannot be overstated. Power distribution systems are highly technical by their nature and an accurate evaluation of system characteristics and resulting interactions can easily overwhelm those with limited experience and/or expertise in the field.
Since the investigation of a power quality problem can represent a significant investment in both time and money, it is important to set a benchmark for evaluating this expenditure. An excellent benchmark for such an evaluation is the level of expenditure created by the problem. It may be expressed as the value of lost production, cost of unplanned down time, rework of off-spec product, equipment damage and repair, or any other parameter resulting from a power quality event which impacts the profitability of a cost center. The advantage of creating this benchmark early in the investigative process is that it may be used to evaluate proposed solutions upon completion of the investigation.
Selection of Power Quality Solutions
Selection and implementation of an effective power quality solution should be centered on the specific load that created the requirement for the enhanced level of service. Implementing a broadbased solution that provides an enhanced level of service for adjacent equipment that does not require it may be uneconomical resulting in cancellation of the project. Since the desired objective is to solve the power quality problem, it is important to seek the most cost-effective solution. If the investigative process has not revealed a definite source or condition responsible for the power quality problem, its findings should be reviewed to ensure that the proposed solution does not further aggravate the problem or prove to be ineffective.
While the specific requirements for an effective power quality solution can vary dramatically between applications or facilities, they generally fulfill four basic functions. These functions, which can be identified as Electrical Isolation, Power Conditioning Glitch Protection and Outage Protection, are described in more detail in the table below.
Each application requires careful consideration to determine the type of power quality mitigation needed to ensure the safe and reliable operation of critical equipment. Benchmarks created during the investigation of the problem can be used to evaluate performance variations between proposed solutions verifying that the most cost-effective solution is selected. The Institute of Electrical and Electronic Engineers (IEEE) has published a series of recommended practice guides and standards related to classification and performance of electrical distribution systems. These publications provide excellent information intended to assist investigators and facility managers in implementing standardized definitions for power quality events and quantifying the performance of proposed solutions.
A question that commonly arises when selecting a power quality solution is how much protection is enough? While a full-coverage system capable of isolating an entire facility from all types of power quality problems may be desirable, it is often impractical, uneconomical and most importantly, unnecessary. It is important not to be constrained by the view that the solution must be electrical or based on conventional battery-based technologies. Minor process changes and/or selection of equipment that is less susceptible to common power quality problems may be more economical than the implementation of an electrical power protection system. This is particularly true for many industrial processes that are relatively immune to transients or waveform distortion but are highly susceptible to momentary power interruptions that typically represent more than 95% of all outages.
External factors such as available space, distribution configuration, environmental conditions, infrastructure requirements and ongoing operating and maintenance costs all influence the selection of the appropriate power quality solution. The costs to accommodate these variables can often exceed the cost of the power protection equipment and should therefore be part of the selection criteria. Careful equipment selection can dramatically reduce the infrastructure costs associated with implementation of a power quality solution.
A typical industrial application highlights the need for careful consideration of all factors when selecting a power quality solution. The traditional approach to power protection is built on a model that is entirely at odds with the setting in many industrial facilities. Conventional systems are based largely on technologies developed for the protection of large computer systems where power demands are relatively stable and predictable, and a clean, temperature-controlled environment is provided to ensure reliable operation of computer equipment. It is therefore not surprising that traditional solutions relying on batteries have many of the same characteristics as the computer equipment they were designed to protect. Since the infrastructure and space needed to provide a clean air-conditioned environment is often at a premium in an industrial setting, implementing a conventional power protection solution can be a costly undertaking.
The past decade has seen the emergence of several new technologies that address many of the constraints limiting the application of conventional power quality solutions. The primary advantage of these systems is their ability to eliminate the need for energy-storage batteries along with their associated infrastructure and maintenance costs, resulting in lower life cycle costs and improved performance. Other advantages include the ability to reduce space and infrastructure requirements by integrating key elements of power protection solution into a single footprint. While these alternative technologies do not eliminate all of the constraints faced by facility managers seeking a power quality solutions, they do open the window to a range of new options which may be better suited to meeting the needs of their specific application.
When a power quality problem is properly analyzed, it becomes possible to select the proper power protection solution for most situations. Once installed and verified, these systems become a valuable ally in the facility manager’s quest to provide critical profit centers with a reliable supply of electricity.
About the Author
Mr. Friesen is the General Manager of Meridium Power Inc. a Canadian company providing power protection solutions based on Written-Pole® Technology. He can be contacted via email at sales@meridiumpower.ca.
The increased use of sensitive electronic equipment, with its stringent input power requirements, has forced companies to place greater emphasis on the quality and reliability of their energy supply. Ironically, much of this emphasis has been directed towards costly solutions that place the primary responsibility for power quality and reliability on local electric utilities. While electric utilities continually strive to improve the quality and reliability of their energy delivery, the requirements for maintaining a reliable and cost-effective distribution system often conflict with the specific power quality requirements of a particular application or customer. The resulting solution is often an unsatisfactory compromise for both the utility and the user.
Fortunately, innovative solutions are emerging which enable facility managers to find the delicate balance between reliability and cost, ensuring that vital energy supplies are available to maintain critical operations. The broad range of technologies available within today’s market, including flywheels, batteries, capacitors, harmonic filters and active power conditioners to name a few, greatly enhance the possibility of finding a costeffective solution for most power quality problems. An added benefit often overlooked by those focusing on the new generation of "critical" applications is that many of these same advancements can also improve the productivity of common industrial processes, which have historically been referred to as “less sensitive” although no less critical to overall productivity.
Flywheel energy storage systems isolate critical
electrical equipment from utility disturbances
Investigating Power Quality Problems
Investigation of any power quality or reliability problem should involve a thorough review of the critical load’s function and power requirements, along with the operation of the electrical supply. A thorough analysis at the point of use may reveal that a defective load or improper application is the problem, saving a great deal of time and energy in finding a solution. An outward approach will assist the investigator in determining the critical point in the distribution system at which it is most cost effective to implement a solution.
Many electric utilities offer services which can assist with these investigations, however it is important to recognize that power quality problems experienced by customers often originate within their own facility and not the utility supply. Initiating an investigation under the premise that the utility source is the cause of the problem may cause investigators to provide an incorrect diagnosis, leading to a broad-based solution that greatly increases the cost of implementation.
The increased demand for these types of investigative services has resulted in the proliferation of high-speed diagnostic equipment with enhanced capabilities for capturing and recording intermittent or high-speed power quality events. When combined with the experience of a competent power quality professional, these instruments provide a wealth of information that can be used to diagnose power quality problems, evaluate power requirements, verify equipment performance and specify appropriate solutions.
PQ Investigations
- Identification
Clearly identify the problem and its impact
on the facility and critical processes - Evaluation
Evaluate the methods, equipment and
expertise needed to properly investigate the
problem - Investigation
Perform a thorough investigation of the
problem identifying the cause and related
impacts - Review
Review the technical findings of the investigation
and relate them to the costs associated
with the problem
PQ Solutions
- Identification
Identify potential solutions for the problem
based on the criteria established by the
investigation - Investigation
Investigate the costs and benefits associated
with implementation of each solution - Evaluation
Evaluate each option from a technical and
economic base to ensure that it meets the
criteria established by the investigation - Implementation
Implement the solution that best meets the
requirements set out by the investigation - Verification
Verify the performance of the equipment
and ensure that it performs as specified
Performance verification of a 75-hp high inertia Power-Ride“ motor designed to provide reliable shaft horsepower during short interruptions.
The importance of using an experienced power quality professional to evaluate the data collected with diagnostic equipment cannot be overstated. Power distribution systems are highly technical by their nature and an accurate evaluation of system characteristics and resulting interactions can easily overwhelm those with limited experience and/or expertise in the field.
Since the investigation of a power quality problem can represent a significant investment in both time and money, it is important to set a benchmark for evaluating this expenditure. An excellent benchmark for such an evaluation is the level of expenditure created by the problem. It may be expressed as the value of lost production, cost of unplanned down time, rework of off-spec product, equipment damage and repair, or any other parameter resulting from a power quality event which impacts the profitability of a cost center. The advantage of creating this benchmark early in the investigative process is that it may be used to evaluate proposed solutions upon completion of the investigation.
| Function | Requirement | Benefit |
| Electrical Isolation | Mitigation against the flow of undesirable voltage and/or current to or from critical electrical equipment | Prevents damage or interference with critical equipment caused by transients, harmonics and noise. |
| Power Conditioning | Provision of a regulated source of voltage and/or frequency protecting against voltage sags, swells or frequency variations | Prevents short and long-term variations of voltage and/or frequency from interfering with the operation of critical equipment |
| Glitch Protection | Mitigation against interruptions caused by momentary loss of voltage lasting from several milliseconds to seconds (typically more than 95% of all utility interruptions) | Prevents momentary loss of voltage resulting from events such as utility re-closure operations from interfering with the operation of critical equipment |
| Outage Protection | Mitigation against interruptions of supply voltage lasting minutes or hours. | Prevents unplanned shutdown of critical equipment due to utility interruptions caused by equipment failures or weather events. |
Selection of Power Quality Solutions
Selection and implementation of an effective power quality solution should be centered on the specific load that created the requirement for the enhanced level of service. Implementing a broadbased solution that provides an enhanced level of service for adjacent equipment that does not require it may be uneconomical resulting in cancellation of the project. Since the desired objective is to solve the power quality problem, it is important to seek the most cost-effective solution. If the investigative process has not revealed a definite source or condition responsible for the power quality problem, its findings should be reviewed to ensure that the proposed solution does not further aggravate the problem or prove to be ineffective.
While the specific requirements for an effective power quality solution can vary dramatically between applications or facilities, they generally fulfill four basic functions. These functions, which can be identified as Electrical Isolation, Power Conditioning Glitch Protection and Outage Protection, are described in more detail in the table below.
Each application requires careful consideration to determine the type of power quality mitigation needed to ensure the safe and reliable operation of critical equipment. Benchmarks created during the investigation of the problem can be used to evaluate performance variations between proposed solutions verifying that the most cost-effective solution is selected. The Institute of Electrical and Electronic Engineers (IEEE) has published a series of recommended practice guides and standards related to classification and performance of electrical distribution systems. These publications provide excellent information intended to assist investigators and facility managers in implementing standardized definitions for power quality events and quantifying the performance of proposed solutions.
A question that commonly arises when selecting a power quality solution is how much protection is enough? While a full-coverage system capable of isolating an entire facility from all types of power quality problems may be desirable, it is often impractical, uneconomical and most importantly, unnecessary. It is important not to be constrained by the view that the solution must be electrical or based on conventional battery-based technologies. Minor process changes and/or selection of equipment that is less susceptible to common power quality problems may be more economical than the implementation of an electrical power protection system. This is particularly true for many industrial processes that are relatively immune to transients or waveform distortion but are highly susceptible to momentary power interruptions that typically represent more than 95% of all outages.
External factors such as available space, distribution configuration, environmental conditions, infrastructure requirements and ongoing operating and maintenance costs all influence the selection of the appropriate power quality solution. The costs to accommodate these variables can often exceed the cost of the power protection equipment and should therefore be part of the selection criteria. Careful equipment selection can dramatically reduce the infrastructure costs associated with implementation of a power quality solution.
A typical industrial application highlights the need for careful consideration of all factors when selecting a power quality solution. The traditional approach to power protection is built on a model that is entirely at odds with the setting in many industrial facilities. Conventional systems are based largely on technologies developed for the protection of large computer systems where power demands are relatively stable and predictable, and a clean, temperature-controlled environment is provided to ensure reliable operation of computer equipment. It is therefore not surprising that traditional solutions relying on batteries have many of the same characteristics as the computer equipment they were designed to protect. Since the infrastructure and space needed to provide a clean air-conditioned environment is often at a premium in an industrial setting, implementing a conventional power protection solution can be a costly undertaking.
The past decade has seen the emergence of several new technologies that address many of the constraints limiting the application of conventional power quality solutions. The primary advantage of these systems is their ability to eliminate the need for energy-storage batteries along with their associated infrastructure and maintenance costs, resulting in lower life cycle costs and improved performance. Other advantages include the ability to reduce space and infrastructure requirements by integrating key elements of power protection solution into a single footprint. While these alternative technologies do not eliminate all of the constraints faced by facility managers seeking a power quality solutions, they do open the window to a range of new options which may be better suited to meeting the needs of their specific application.
When a power quality problem is properly analyzed, it becomes possible to select the proper power protection solution for most situations. Once installed and verified, these systems become a valuable ally in the facility manager’s quest to provide critical profit centers with a reliable supply of electricity.
About the Author
Mr. Friesen is the General Manager of Meridium Power Inc. a Canadian company providing power protection solutions based on Written-Pole® Technology. He can be contacted via email at sales@meridiumpower.ca.
