INTRODUCTION The power quality of the electrical power is one of the important factors that hurdle to deliver power to all customers in a safe, reliable and economical mode. The power quality is defined as the electric power consisting of specific range of voltage, current and frequency that results in normal operation of customer equipment. However, this situation is difficult to achieve in practice. The term harmonics referred to Power quality in ideal world would mean how pure the voltage is, how pure the current waveform is in its sinusoidal form. Nowadays the electronic equipments became more powerful and versatile, used for the conversion, variation and regulation of electrical power in commercial, industrial and residential installations. As a result harmonic distortion has a catastrophic impact on a power system and equipment: increasing harmonics “pollution”. Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Photovoltaic has been derived from the combination of two words, "Photo" and "Voltaic". Photo means light and Voltaic means electricity. It is a technology that converts light directly into electricity. In this paper the PV system inverter is also utilized to compensate/neutralize the harmonics generated by a non-linear load and thus can help to reduce the harmonics pollution on the distribution network. In Section II, the system model is described whereas in Section III the performance and the detail simulation study results of the proposed PV-STATCOM are presented and discussed. Finally, Section IV concludes the study of this paper. SYSTEM MODEL The single line diagram for the distribution network model is pre... ... middle of paper ... ...aspects are summarized in Fig. 3.28. A and B depicts the injection of harmonic active and harmonic reactive powers by the PV solar farm inverter to compensate for the harmonics generated by the power electronics loads connected downstream of the system in night and day respectively. When the power generation from PV system is at its rated value during day-time, the solar farm inverter cannot be used to provide the reactive power. For lesser active power generation, there is always an opportunity to provide simultaneous active and reactive power. However, during night-time, the PV system will draw a very small amount of active power to maintain the voltage across the DC side capacitor. This active power is essential to overcome the losses associated with the inverter. When the PV system does not produce any active power, the available reactive power capacity is 100%.
Turchi, Craig. 2010. Solar Power and the Electric Grid. edited by National Renewable Energy Laboratory.
N. Mohan, T.M. Undeland, W.P. Robbins, “Power Electronics”, John Wiley & Sons, Inc. © 2003
Depending on excitation, a synchronous generator can either generate or consume reactive power within its capacity. Cables generate reactive power due to high shunt capacitance, while overhead lines and transformers are reactive power consumers, which cause most of reactive power losses. Most loads, either by industry consumer or by private consumer, are inductive loads, thus they also absorb reactive power. The reactive power generated by synchronous generators is usually less than the demand of loads. Hence, the generation and requirement need to be equalized by capacitive compensation devices, such as capacitor banks, SVC and STATCOM
Solar Photovoltaic power is one of the rapid growing energy sources in the world. The need for energy security and stability is driving governments across the world to promote and develop renewable power sources. The global solar Photovoltaic market witnessed high growth in 2009 and 2010, with 24,600 MW of installed capacity coming online in these two years compared to the 8,912 MW installed in 2007 and 2008. Cumulative installed capacity increased from 16,127 MW in 2008 to 40,727 MW in 2010. Europe is the leading solar PV market, with a share of 76% of the total cumulative installed capacity, followed by the Asia-Pacific region, accounting for a share of 16.0% in 2010.
As the world grows older, many new young inventors and scientists create new methods to make the world a safer and more sufficient place. There are many new methods for generating energy such as: wind, geothermal, biomass, and solar energy. Solar energy is the radiant energy emitted by the sun, which after being processed is used as solar power. Solar energy is also an example of electromagnetic radiation. The electromagnetic radiation travels to the earth in various wavelengths, most of which are invisible to the human eye like gamma or ultraviolet rays.
Rooftop solar is comprised of solar panels, an inverter, and a meter connection to the electric grid. Solar panels are made from different types of silicon that produce direct current when exposed to sunlight. The direct current from solar panels is routed via metallic wires into an inverter which converts direct current to alternating current, also known as DC to AC conversion (Solarworld, 2014). The output of the inverter is tied into an electric panel. This is where your electric meter gets involved with tracking kilowatt hours produced by your solar panels before they are fed back into the electric grid (Zipp, 2013).
Nonlinear loads are the most common causes of harmonics and neutral currents. Various electrical equipments such as transformers, motors and cables are affected by harmonics. Equipments such as PC’s and printers using switched mode power supply produce neutral currents.
The dc power input to the inverter is obtained from an existing power supply network or from a rotating alternator through a rectifier or a battery, fuel cell, photovoltaic array or magneto hydrodynamic generator. The filter capacitor across the input terminals of the inverter provides a constant dc link voltage. The inverter therefore is an adjustable-frequency voltage source. The configuration of ac to dc converter and dc to ac inverter is called a dc-link converter. Inverters can be broadly classified into two types, voltage source and current source
These inverters operate coupled to the electrical distribution network and therefore must be able to produce almost perfect sinusoidal voltages and currents.
High performance MPPT includes pulse width modulation (PWM) used in large scale PV module, whereas low performance MPPT includes pulse frequency modulation (PFM) used in small scale PV module. PFM is used instead of PWM to attain better efficiency at low power levels. PWM continuously activate the switches of the converter at a fixed frequency whereas PFM adjusts the switching activity of the available power. Higher ripple current can be produced for the frequency modulation which reduces the efficiency. To reduce this problem current limiter is used for higher switching frequency.
The proposed inverter configuration consists of boost converter, Dc bus, three phase inverter, 12 terminal transformer, LC filter and three phase load. The figure 1shows PV inverter topology and one set of five inverter depicted in figure 2.
At our new house, we have two stand alone pedestals with six 170W panels on each pedestal, making for 2040W or 2kW solar system. According to Mr. Solar.com, “this type of energy production, known as the Photovoltaic Effect, is achieved by solar panels converting sunlight into energy. Solar panels are made up of several individual solar cells, composed of layers of silicon, phosphorous (which provides the negative charge), and boron (which provides the positive charge). Solar panels absorb the sunlight’s photons and by doing so initiate an electric current, producing electrons. The resulting energy generated from photons striking the surface of the solar panel allows electrons to be knocked out of their atomic orbits and released into an electric field generated by the solar cells, which then pull these free electrons into a DC or directional current.” This electricity then proceeds to a mechanical room beneath our house to a charge controller, which regulates the amount of energy sent to our 24V batteries to be stored. From these batteries, the electricity goes to an inverter, which then changes the DC to AC or alternating current in order to use our modern electrical appliances and gadgets.
In this section, The basics of electromagnetic transients, HV Capacitors banks and their relations and functions in the power system are presented.
Occasional cloud cover or hazy skies has more effect on power generated on CSP system than PV system. Furthermore, CSP need to be scaled well. In particular, CSP systems must be large enough (tens of megawatts or larger) to reach its optimum point where maximum efficiency and minimum cost is
The power electronics equipments, such as inverter, chopper & rectifier have switching devices and their output produces voltage & current harmonics to the system from which they are working and these harmonics affect the operation of other equipments connected to the same system through conduction or by radio interference. This harmonics gives the following disadvantage: (a) harmonics current will lead to excessive heating in the induction motor connected with the thyristor system and this will reduce the load