Hello, my name is Steve, I am the owner of a small company of 95 people. Since 1 year we have built a new office building fully automated: it’s great! I mean, both the working comfort and energy efficiency issues.
Intelligent building : 100% building controls
In my previous article I presented the principle for avoiding production losses when photovoltaic systems are located in such cases where there is shadow of trees, dust, chimneys, antenna, other buildings … We speak of photovoltaic shading.
Then I presented a good solution to avoid these which is distributed MPP Tracking: one micro inverter per photovoltaic module to track individual Maximum Power Point. I also detailed 2 design approaches with pro’s & con’s arguments.
In this article, I will give some concerns and questions about photovoltaic reliability.
I find interesting to summarize credibility basics in this Electrical Engineering Blog because i feel this seems to apply well to this Blog and also it may help all visitors, contributors and also the moderator team, to have a better understanding.
I produced this information from a source given in Problogger site.
From ProBlogger site
7 blog quality principles are interesting to cover: Longevity, Experience, Expertise, Blog design, Writing skills, Readership volume and readers participation & Consistency. Finally it’s nice to see that this is common sense …
How to achieve “harmonic mitigation” ?
Several different solutions are proposed for Harmonic mitigation. The right choice is always dependent on a variety of factors, such as the activity sector, the applicable standards, the power level …. Several solutions are relative to Variable Speed Drives, as this type of electrical equipment represents a large part of the installed power in industrial installations and the most significant power harmonic current generators.
I will explain here the solutions and its principle for avoiding production losses when photovoltaic systems are located in cases where there is shadow of trees, dust, chimneys, antenna, other buildings or specific relief. The idea is to install one micro inverter per Photovoltaic module to track individual Maximum Power Point. I will detail 2 design approaches with their benfits & drawbacks.
photovoltaic shading
Precision timing is required for monitoring and control of electrical power networks where power system reliability is important. Circuit breaker control schemes require precise timing to ensure proper operation, and Sequence of Events Recording systems report events with one-millisecond precision to aid diagnostics and troubleshooting. Typical “critical power” applications include electric utility networks, data centres, hospitals, water treatment plants, refineries, and other process industries.
Electrical protection and lightning protection
I have a query on earthing system design. One designer has submitted me an earthing plan which interconnects the earth electrodes meant for equipment earthing and those for lightning protection purposes. By combining the earth electrodes he achieves overall earth resistance below one ohm required by IS 3043 (Indian standard). But my question is whether this is an acceptable practice followed by industry or the earth electrodes of the two systems (protective earthing and lightning protection) can not be combined this way?
Would appreciate feedback. thanks in advance.
D. Sunil
Power factor has been defined earlier as a function of active and apparent power. For sinusoidal (undistorted) voltage and current, a vector representation is also possible and helpful.
For most electrical loads like motors, the current I is lagging behind the voltage V by an angle phi.
Ia is called the “active” component of the current.
Ir is called the “reactive” component of the current.
Voltage and current vectors
looking for Donors
In 2010, many changes lie in store for us:
1. We are going to open up this blog to any interested donors. Our objective is to use the donations obtained to develop its audience and assist with support. In exchange, for those who so wish, we are proposing to allow each donor to place his logo (and Web link) on the blog. You yourself decide how much you wish to donate…
2. The aim is more than ever the technical quality of the articles and exchanges in the field of electrical equipment, electrical installation and energy management: today’s experiences and tomorrow’s solutions…
3. A team is being set up to moderate this blog: it will consist of Martine, François, Stéphane, Jean-Paul and Laurent.
Have an excellent year!
The Electrical Engineering blog moderator team
Draft for a new IEC standard
At an hour when advices for energy efficiency are to be written, the challenge is to aim at completed general installations rules for electrical installations of buildings, in the way to obtain the highest possible service for the lowest energy consumption. This shall be true in new and also in existing buildings.
electrical energy efficiency, IEC standard draft
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