04-05-2012, 01:57 PM
Super Capacitors Energy Storage System For Power Quality Improvement
[attachment=21267]
ABSTRACT:
Power quality problem causes a misoperation or failure of end user equipments. Distribution network, sensitive industrial loads and critical commercial operations suffer
from outages and service interruptions which can cost financial losses to both utility and
consumers. In India the use of electronic loads is increasing very fast and the gap between demand and the supply have made the reliability and power quality a critical
issue. Further there is continuous thrust on optimal utilization of the non-conventional
energy sources along with the central power station. In this paper a critical review have
been presented chronologically various work to improve quality of power with the help of energy storage device i.e. Supercapacitors energy storage systems for ASD, elevators,
UPS, and power distribution system, ride through capability, real power injection and
reactive power injection for stabilization of the system.
Supercapacitor is a double layer capacitor; the energy is stored by charge transfer at the boundary between electrode and electrolyte. The amount of stored energy is function of the available electrode and electrolyte surface, the size of the ions, and the level of the electrolyte decomposition voltage. Super capacitors are constituted of two electrodes, a separator and an electrolyte. The two electrodes, made of activated carbon provide a high surface area part, defining so energy density of the component. On the electrodes, current collectors with a high conducting part assure the interface between the electrodes and the connections of the super capacitor. The two electrodes are separated by a membrane, which allows the mobility of charged ions and forbids no electronic contact. The electrolyte supplies and conducts the ions from one electrode to the other [5, 12].
Usually super capacitors are divided into two types: double-layer capacitors and electrochemical capacitors. The former depends on the mechanism of double layers, which is result of the separation of charges at interface between the electrode surface of active carbon or carbon fiber and electrolytic solution. Its capacitance is proportional to the specific surface areas of electrode material.
Keywords:
Power Distribution System, Supercapacitors Energy Storage System, Distributed
Generation, Reliability, Power Quality, Equivalent Series Resistance and Equivalent Parallel Resistance.
Introduction
The first complete electric power system was built by the Thomas Edison in September
1882 in the New York city ;through the steam driven dc generator supplying at 110 Volt.
Due to dc system and low voltage level; the losses in transmission line (I2R) puts the
limitation for the long distance transmission
of the power.
After development of the
transformer and ac transmission system by
L. Gaulard and J.D. Gibbs led to ac electric
power system. In the year 1889, the first ac transmission line in North America was put in
to operation in Oregon between Willamette falls and Portland. So the literature reveals that
the power system was inherently of dispersed generation nature or decentralized generation
i.e. distributed generation (DG) is no new concept [1].
Nowadays the power system is in a process of undergoing from regulated market to
deregulated, centralized to more localized system that are situated to near the load; the
reason behind the increased concern for environment, to utilize renewable energy
technologies, flexibility , lower initial investment costs, lower time of project completion,
electricity market liberalization, developments in DG technology, constraints on the
construction of new transmission lines, increased customer demand for highly reliable
electricity [2,3] .Further with the fast increase in electronic loads has made the quality of
power supply a critical issue? .Since the power distribution system must be able to supply
the power reliably while maintaining the power quality through out the year; so there is
strong need of energy storage capability with the central power utility and also the non
conventional energy resource .
The reason behind overview of supercapacitors energy storage system is that
supercapacitors are less weighty than that of battery of the same energy storage capacity, a
fast access to the stored energy, Charging very fast than battery, Charge/discharge cycle is
106 time, storage capacity independent of number of charging/discharging cycles, energy
density for Supercapacitor is 10 to 100 times larger than of traditional capacitors(typical
20-70 MJ/m3), capacities up to 5F/cm2, life cycles 25-30 years, high efficiency
(95%),power density 10 times greater than batteries, Charge and discharge time very less,
rated capacitance value ranging from 0.043-2700F,nominal voltage ranging from 2.3 to 400
V,rated current ranging from 3-600 A, operating temperature ranging -40°C to
85°C,Maintenance free, very low leakage current, also non polar [4, 5, 6, 7].
Power Quality Issues
Voltage flicker
DG may cause voltage flicker as a result of starting a machine or sudden change in the
DG output which results in a significant voltage change on the feeder. In case of non
dispatchable source, the output fluctuates. This study investigates the impact of DGs on voltage flicker which is considered recently as an urgent power quality problem that can affect motor starting, temperature rise, overloading of generators, motors and may cause health risk problems due to the annoying light flicker which is consequence of voltage fluctuation. The study includes three days monitoring of a residential building with and without DG connected. Results obtained reveal a strong relation between voltage frequency deviations produced in the presence of DG and the voltage flicker detected.
[attachment=21267]
ABSTRACT:
Power quality problem causes a misoperation or failure of end user equipments. Distribution network, sensitive industrial loads and critical commercial operations suffer
from outages and service interruptions which can cost financial losses to both utility and
consumers. In India the use of electronic loads is increasing very fast and the gap between demand and the supply have made the reliability and power quality a critical
issue. Further there is continuous thrust on optimal utilization of the non-conventional
energy sources along with the central power station. In this paper a critical review have
been presented chronologically various work to improve quality of power with the help of energy storage device i.e. Supercapacitors energy storage systems for ASD, elevators,
UPS, and power distribution system, ride through capability, real power injection and
reactive power injection for stabilization of the system.
Supercapacitor is a double layer capacitor; the energy is stored by charge transfer at the boundary between electrode and electrolyte. The amount of stored energy is function of the available electrode and electrolyte surface, the size of the ions, and the level of the electrolyte decomposition voltage. Super capacitors are constituted of two electrodes, a separator and an electrolyte. The two electrodes, made of activated carbon provide a high surface area part, defining so energy density of the component. On the electrodes, current collectors with a high conducting part assure the interface between the electrodes and the connections of the super capacitor. The two electrodes are separated by a membrane, which allows the mobility of charged ions and forbids no electronic contact. The electrolyte supplies and conducts the ions from one electrode to the other [5, 12].
Usually super capacitors are divided into two types: double-layer capacitors and electrochemical capacitors. The former depends on the mechanism of double layers, which is result of the separation of charges at interface between the electrode surface of active carbon or carbon fiber and electrolytic solution. Its capacitance is proportional to the specific surface areas of electrode material.
Keywords:
Power Distribution System, Supercapacitors Energy Storage System, Distributed
Generation, Reliability, Power Quality, Equivalent Series Resistance and Equivalent Parallel Resistance.
Introduction
The first complete electric power system was built by the Thomas Edison in September
1882 in the New York city ;through the steam driven dc generator supplying at 110 Volt.
Due to dc system and low voltage level; the losses in transmission line (I2R) puts the
limitation for the long distance transmission
of the power.
After development of the
transformer and ac transmission system by
L. Gaulard and J.D. Gibbs led to ac electric
power system. In the year 1889, the first ac transmission line in North America was put in
to operation in Oregon between Willamette falls and Portland. So the literature reveals that
the power system was inherently of dispersed generation nature or decentralized generation
i.e. distributed generation (DG) is no new concept [1].
Nowadays the power system is in a process of undergoing from regulated market to
deregulated, centralized to more localized system that are situated to near the load; the
reason behind the increased concern for environment, to utilize renewable energy
technologies, flexibility , lower initial investment costs, lower time of project completion,
electricity market liberalization, developments in DG technology, constraints on the
construction of new transmission lines, increased customer demand for highly reliable
electricity [2,3] .Further with the fast increase in electronic loads has made the quality of
power supply a critical issue? .Since the power distribution system must be able to supply
the power reliably while maintaining the power quality through out the year; so there is
strong need of energy storage capability with the central power utility and also the non
conventional energy resource .
The reason behind overview of supercapacitors energy storage system is that
supercapacitors are less weighty than that of battery of the same energy storage capacity, a
fast access to the stored energy, Charging very fast than battery, Charge/discharge cycle is
106 time, storage capacity independent of number of charging/discharging cycles, energy
density for Supercapacitor is 10 to 100 times larger than of traditional capacitors(typical
20-70 MJ/m3), capacities up to 5F/cm2, life cycles 25-30 years, high efficiency
(95%),power density 10 times greater than batteries, Charge and discharge time very less,
rated capacitance value ranging from 0.043-2700F,nominal voltage ranging from 2.3 to 400
V,rated current ranging from 3-600 A, operating temperature ranging -40°C to
85°C,Maintenance free, very low leakage current, also non polar [4, 5, 6, 7].
Power Quality Issues
Voltage flicker
DG may cause voltage flicker as a result of starting a machine or sudden change in the
DG output which results in a significant voltage change on the feeder. In case of non
dispatchable source, the output fluctuates. This study investigates the impact of DGs on voltage flicker which is considered recently as an urgent power quality problem that can affect motor starting, temperature rise, overloading of generators, motors and may cause health risk problems due to the annoying light flicker which is consequence of voltage fluctuation. The study includes three days monitoring of a residential building with and without DG connected. Results obtained reveal a strong relation between voltage frequency deviations produced in the presence of DG and the voltage flicker detected.