WHAT IS POWER QUALITY:
Power quality is the measurement of how close to perfect an electrical voltage is at any given time or point. High-quality electrical voltage is a sine wave that measures exactly what is expected in both voltage and frequency. A high-quality electrical source is one that can deliver all the electrical energy needed without any change in the voltage. In the past, responsibility for power quality was thought to be the power companies’ problem but that isn’t really true. In almost every case, the circumstances that impact power quality are outside of the power company’s control.
Historically, most power quality problems were considered to be those things that affected the distribution of power. Lightning, line or transformer failures, and/or very high electrical demands (brownouts) on the electrical network are just a few. However, most power quality problems are due to technological changes and the way electricity is now being used by people.
With each decade, the manufacturers of Power Conditioning and Power Quality equipment are faced with a new set of challenges. As technology changes in all industries, so does the need for ensuring the new technology does not impact the older systems and cause electrical problems. Power quality problems caused by this continued equipment improvement and cost reduction have forced large critical power protection systems to look into the reasons for this change in equipment and their function. There are several facts that will force changes in the technology/topology of power protection systems.
POWER CONDITIONING:
The role of power conditioning systems in the past was to protect the customer’s equipment from power quality problems that occurred external to their facility. Today we must also deal with power quality problems caused by their own equipment.
While power requirements are decreasing for individual pieces of equipment, the electrical distortion caused by the newer, more efficient power supplies degrades the performance of the electrical system both inside and outside the facility. Utilities are unable to provide the high quality and reliability in electrical power required to meet the ever-increasing power quality standards of newer equipment.
In the 1970’s and 1980’s, the problems were most felt in large data centers using sensitive computers. Power quality problems were addressed with Uninterruptible Power Systems, Power Distribution Units, and on site Power Generation. In the 1990’s, these problems increased and moved into factories, offices, and anywhere solid-state devices are used. The question now is “Can these systems deal with the new types of critical load?” In many cases, the answer is, “Not without minor, and in some cases, major design changes.”
The issues are becoming more technical and much harder to explain to the design Engineers as they are not aware of changes that will occur after the original build. This document will explain the problems associated with harmonics.
EFFECT OF POOR POWER QUALITY:
Power quality is a very important issue that should be addressed as poor power quality costs money and in some cases downtime. We will look at some direct and indirect costs attributed to power quality.
Direct cost is the loss of production due to a voltage problem, which trips motor and control devices that stop the manufacturing process. It is the loss of products not produced and the labor charges for removing any damaged materials as well as employee wages paid while waiting for the process to restart.
Indirect cost is the replacement of other equipment that becomes stressed by changing electrical voltages. As an example, a solid-state motor drive fails due to voltage spikes over time. These are commonly caused by power factor capacitors switching on and offline to correct varying power factors. However, the failure and subsequent damage to the machine will be untimely because is not caused by any one spike but by numerous spikes occurring over a period of time. With this type of power quality damage, it is impossible to avoid an outage.
Power Quality Solutions
Delta PQC series power quality solution consists of the Active Power Filter (APF) and Static VAR Generator (SVG). Both provide an active compensation solution based on power electronics technology.
Compared with conventional passive compensation solutions such as capacitor banks, an active compensation solution improves the reliability and quality of the power distribution system.
Special Features of Delta Power Quality Solution:
High Adaptability
- A wider range of operating temperatures
Delta PQC series APF & SVG can normally work from -10~55°C, which is suitable for most applications - Withstands extreme electrical condition
Delta’s PQC series APF & SVG can withstand severe harmonic distortion of voltage, they can work normally under conditions with THDu (total harmonic distortion of voltage) up to 15% - Compatible with diesel generators
Simple and Flexible Application
- The Delta PQC series APF & SVG’s modular structure makes it easy for installation, maintenance, and capacity expansion.
- APF & SVG modules can be embedded in Delta’s standard cabinets or third-party cabinets, making it possible to customize cabinets for special requirements.
Excellent Compensation Capability
- Delta’s PQC series APF & SVG adopts 3-level inverter topology with 3pcs modular IGBT and up to 30 kHz switching frequency, which provides excellent power quality compensation accuracy, response speed and output ability.
High Reliability
- Module redundancy technology
- Intelligent air cooling technology
- Top-brand electronic components
- Advanced production technology