26-03-2011, 11:45 AM
presented by:
G.HARINATHAREDDY
[attachment=11046]
Abstract
In little more than ten years, electricity power quality has grown from obscurity to a major issue. Electronic converters and power electronics gave birth to numerous new applications, offering unmatched comfort, flexibility and efficiency to the customers.These equipments are highly sensitive to poor power quality. These require reliable and good power quality free from all power quality issues.However, their proliferation during the last decade is creating a growing concern and generates more and more problems: not only these electronic loads pollute the AC distribution system with harmonic currents, but they also appear to be very sensitive to the voltage distortion. Then, electricity power quality is becoming a major issue for utilities and for their customers, and both are quickly adopting the philosophy and the limits proposed by the new
Today, recent advances in power electronic technology are providing an unprecedented capability for conditioning and compensating harmonic distortion generated by the non-linear loads. This new innovative active conditioner appears to be the easiest of use, the most flexible, the most efficient and cost effective one Power quality monitors assist the troubleshooter to identify and solve many power quality problems. The paper presents examples showing how to analyze these clues, but also shows that similar disturbance wave shapes may still have radically different causes.
INTRODUCTION:
The power quality problem is defined as any problem manifested in voltage, current or frequency deviations that results in mal-operation of customer equipment. The power quality problem causes the deterioration of performance of various sensitive electronic and electric equipments. The good quality of power can be specified as The supply voltage should be within guaranteed tolerance of declared value.The waveshape should be pure sine wave within allowable limits for distortion.The voltage should be balanced in all three phases.Supply should be reliable i.e continuous availability without interruption Modern industrial machinery and commercial computer networks are prone to many different failure modes. When the assembly line stops, or the computer network crashes for no apparent reason, very often the electric power quality is suspected. It is a convenient culprit, as it is invisible and not easy to defend. Power quality problems may be very difficult to troubleshoot, and often the electric power may not have any relation to the actual problem. For example, in an industrial plant the faults of an automated assembly machine may ultimately be traced to fluctuations in the compressed air supply or a faulty hydraulic valve. Or in an office building, the problems on a local area network may be find their root cause with coaxial cable tee locations that are too close together, causing reflections and signal loss. Monitoring after the event has already happened tells us little about the past.
Why power quality is so important?
Power quality is an increasingly important issue for all businesses. Problems with powering and grounding can cause data and processing errors that affect production and service quality.
Lost production: Each time production is interrupted, your business loses the margin on the product that is not manufactured and sold.
Damaged product: Interruptions can damage a partially complete product, cause the items to be rerun or scrapped.
Maintenance: Reacting to a voltage disruption can involve restoring production, diagnosing and correcting the problem, clean up and repair, disposing of damaged products and, in some cases, environment costs.
Hidden costs: If the impact of voltage sag is a control error, a product defect may be discovered after customer delivery. The costs of losing repeat sales, product recalls and negative public relations can be significant and hard to quantify.
G.HARINATHAREDDY
[attachment=11046]
Abstract
In little more than ten years, electricity power quality has grown from obscurity to a major issue. Electronic converters and power electronics gave birth to numerous new applications, offering unmatched comfort, flexibility and efficiency to the customers.These equipments are highly sensitive to poor power quality. These require reliable and good power quality free from all power quality issues.However, their proliferation during the last decade is creating a growing concern and generates more and more problems: not only these electronic loads pollute the AC distribution system with harmonic currents, but they also appear to be very sensitive to the voltage distortion. Then, electricity power quality is becoming a major issue for utilities and for their customers, and both are quickly adopting the philosophy and the limits proposed by the new
Today, recent advances in power electronic technology are providing an unprecedented capability for conditioning and compensating harmonic distortion generated by the non-linear loads. This new innovative active conditioner appears to be the easiest of use, the most flexible, the most efficient and cost effective one Power quality monitors assist the troubleshooter to identify and solve many power quality problems. The paper presents examples showing how to analyze these clues, but also shows that similar disturbance wave shapes may still have radically different causes.
INTRODUCTION:
The power quality problem is defined as any problem manifested in voltage, current or frequency deviations that results in mal-operation of customer equipment. The power quality problem causes the deterioration of performance of various sensitive electronic and electric equipments. The good quality of power can be specified as The supply voltage should be within guaranteed tolerance of declared value.The waveshape should be pure sine wave within allowable limits for distortion.The voltage should be balanced in all three phases.Supply should be reliable i.e continuous availability without interruption Modern industrial machinery and commercial computer networks are prone to many different failure modes. When the assembly line stops, or the computer network crashes for no apparent reason, very often the electric power quality is suspected. It is a convenient culprit, as it is invisible and not easy to defend. Power quality problems may be very difficult to troubleshoot, and often the electric power may not have any relation to the actual problem. For example, in an industrial plant the faults of an automated assembly machine may ultimately be traced to fluctuations in the compressed air supply or a faulty hydraulic valve. Or in an office building, the problems on a local area network may be find their root cause with coaxial cable tee locations that are too close together, causing reflections and signal loss. Monitoring after the event has already happened tells us little about the past.
Why power quality is so important?
Power quality is an increasingly important issue for all businesses. Problems with powering and grounding can cause data and processing errors that affect production and service quality.
Lost production: Each time production is interrupted, your business loses the margin on the product that is not manufactured and sold.
Damaged product: Interruptions can damage a partially complete product, cause the items to be rerun or scrapped.
Maintenance: Reacting to a voltage disruption can involve restoring production, diagnosing and correcting the problem, clean up and repair, disposing of damaged products and, in some cases, environment costs.
Hidden costs: If the impact of voltage sag is a control error, a product defect may be discovered after customer delivery. The costs of losing repeat sales, product recalls and negative public relations can be significant and hard to quantify.
