Actionari Electrice Dirijate – Mijloc Eficient de

Economisire a Energie Electrice

ChisinauMoldexpo - Martie 2011

ACADEMIA DE STIINTE A MOLDOVEI Institutul de Energetica

Dr.Hab. Valentin Olesciuk

Reference

V. Oleschuk, “50 Years of Power Electronics: Its Importance

and New Dimensions”, Invited Lecture at the University of

Bologna (Italy), February 1st, 2011

What is subject of Power Electronics?

Power Electronics is the application of solid-state electronics for the control and conversion of electric power.

Power Electronics is the technology associated with the efficient conversion, control and conditioning of electric power by static means from its available input form into the desired electrical output form.

Power electronic converters can be found wherever there is a need to modify a form of electrical energy (i.e. change its voltage, current or frequency). The power range of these converters is from some milliwatts (as in a mobile phone) to hundreds of megawatts (e.g. in a high voltage transmission system). With "classical" electronics, electrical currents and voltage are used to carry information, whereas with power electronics, they carry power. Thus, the main metric of power electronics becomes

the efficiency.

What is subject of Power Electronics?

Energy saving by means of Power Electronics

CONTROL AND CONVERSION BY ELECTRONIC SWITCHING ARE HIGHLY EFFICIENT THAN BY RHEOSTATIC CONTROL

• NEARLY 60% OF GRID ENERGY IN USA AND EU IS CONSUMED IN MACHINE DRIVES – MAINLY FOR FLUID FLOW CONTROL BY PUMPS AND FANS

• TRADITIONALLY, FLUID FLOW IS CONTROLLED BY THROTTLE OR DAMPER OPENING WITH INDUCTION MOTOR RUNNING AT CONSTANT SPEED

• VARIABLE SPEED DRIVE WITH FULLY OPEN THROTTLE OR DAMPER CAN IMPROVE DRIVE EFFICIENCY BY UP TO 30% AT LIGHT LOAD

• LIGHT LOAD FLUX PROGRAMMING CONTROL CAN FURTHER IMPROVE DRIVE EFFICIENCY BY 20% • VARIABLE SPEED LOAD-PROPORTIONAL AIR-CONDITIONER/HEAT PUMP CAN SAVE ENERGY UP TO 30%

• NEARLY 20% OF GRID ENERGY IS CONSUMED IN LIGHTING

• HIGH FREQUENCY FLUORESCENT LAMPS ARE 4-TIMES MORE EFFICIENT AND HAVE 10-TIMES LONGER LIFE THAN INCANDESCENT LAMPS

• EMERGING SOLID STATE LED LAMPS ARE 8-TIMES MORE EFFICIENT AND HAVE 50-TIMES LONGER LIFE THAN INCANDESCENT LAMPS

Power electronic converters: DC-AC (inverters)

.Topology of a three-level neutral-point-clamped (NPC) inverter

High-power converters

High-power converters: application examples

Power Electronics – energy saving potential

Power Electronics – energy saving potential (drives)

Power Electronics – energy saving potential (drives)

Power Electronics – energy saving potential (drives)

Motor drives use 50-60% of all electrical energy consumed in the developed world. By usingpower electronics controlled motor drives a potential reduction in energy consumption of 20-30% is achievable

Частотно-регулируемые электроприводы насосных станций

Начиная с 80-х годов прошлого века по разработкам и рекомендациям Института энергетики АНМ внедрено более 50 систем регулируемого электропривода в мелиорации, жилищно-коммунальном хозяйстве и в промышленности Республики Молдова, с диапазоном мощностей от 1,5 до 300 кВт, в том числе на базе разработанных в Институте транзисторных и тиристорных преобразовательных устройств. Средняя экономия электроэнергии за счет использования регулируемых электроприводов составляет 25%, срок службы электродвигателей увеличивается при этом в 2 – 3 раза. В частности, в перечень базовых внедрений входят:- 6 опытно-промышленных образцов систем управления электроприводами многоагрегатных насосных установок на насосных станциях оросительных систем; -автоматизированные тиристорные электроприводы главной и районной канализационных насосных станций г Яловены мощностью соответственно 300 и 250 кВт, суммарная экономия электроэнергии на которых составляет 220 000 кВт-час в год;

Транзисторные преобразователи для систем электропривода

Транзисторные преобразователи частоты мощностью 1.5 – 5 кВт для регулируемых в широких пределах асинхронных электроприводов различного функционального назначения

Транзисторные многофункциональные преобразователи частоты с гибкими алгоритмами управления для автоматизации сложных технологических процессовв области химических технологий

Power Electronics in renewable energy systems

The global electrical energy consumption is still rising and there is a steady demand to increase the power capacity. It is expected that it has to be doubled within 20 years.

Nowadays one of the basic concepts is to change the electrical power production sources from the conventional, fossil based energy sources to renewable energy resources.

Between the most emerging renewable energy sources there are wind energy, photovoltaic, wave generators, fuel cells, small hydro.

The main advantages of using renewable energy sources are the elimination of harmful emissions and the inexhaustible resources of the primary energy.

The main disadvantage, apart from the higher costs, e.g. photovoltaic, is the uncontrollability.

The forecast for worldwide total installed capacity

Power Electronics in wind power systems

The key to reduce price is to increase the power level and today turbines of 4-5 MW are used around the world. It is expected 10 MW wind turbines will be in practice soon.

Power Electronics in wind power systems

The countries with the highest total installed capacity are Germany, Spain and Denmark. A number of other countries, including Italy, the UK, the Netherlands, China, Japan and Portugal have also reached the 1,000 MW mark of installed capacity. Europe is still leading the market.

Photovoltaic (PV) based solar power is like the wind turbines a technology for a booming industry; since 1980, when the terrestrial applications began. The annual installation of PV power has increased to above 7 GWp leading to cumulative installed PV power by the end of 2009 reaching to approximately 15 GWp according to EPIA which actually is 10 % of the wind power capacity.

Power Electronics in photovoltaic systems

Development and prognosis of specific cost and production quantity for the PV inverter of nominal powers between 1 and 10 kW during two decades (¦ indicates specific

prices of products on the market).

Historically the main market segments for PV were theremote industrial and developing country applicationswhere PV power over long term is often more costeffective than alternative power options such as diesel generator or mains grid extension.

Worldwide, the cumulative share of off-grid to gridconnected applications is approximately 1:4 at the present time. However, this is not the case in every reporting country. In Sweden, Norway and Finland, the most common applications are for vacation cottages, while in Australia, Mexico, and France achieving rural electrification is a key objective. In Canada, Israel and Korea, commercial and telecommunications applications dominate.

Power Electronics in photovoltaic systems

Example of implementation: Department of Electrical Engineering of the University of Bologna (G. Grandi et al., IEEE Tr. on PE, 2009)

Power Electronics in photovoltaic systems

Experimental set-upPV panels on the roof of the Department

Why Power Electronics is so important to-day?

INCREASINGLY IMPORTANT ROLE OF POWER ELECTRONICS IN ENERGY SAVING (CONTROLLED ELECTRIC DRIVES, ETC.) THAT HELPS TO SOLVE GLOBAL WARMING PROBLEM

• FAST GROWTH OF RENEWABLE ENERGY RESOURCES (WIND, PHOTOVOLTAIC AND FUEL CELLS) THAT ARE HIGHLY DEPENDENT ON POWER ELECTRONICS

• GROWTH OF ELECTRIC AND HYBRID VEHICLES AND OTHER GREEN TRANSPORT SYSTEMS, WHICH ARE POWER ELECTRONICS INTENSIVE

• IMPROVES PRODUCTIVITY AND PRODUCT QUALITY IN AUTOMATED INDUSTRIAL SYSTEMS

• ENABLES VERY EFFICIENT POWER CONVERSION AND CONTROL IN MODERN ELECTRICAL ENERGY PROCESSING SYSTEMS (HVDC, FACTS, UPS, ETC.)

• VERY IMPORTANT ELEMENT IN BULK ENERGY STORAGE (BATTERY, FLYWHEEL, PUMPED STORAGE, ULTRA CAPACITORS, FUTURE HYDROGEN ECONOMY)

• SMART GRID OF TOMORROW WITH INTENSIVE POWER ELECTRONICS WILL PERMITOPTIMUM RESOUCE UTILIZATION AND ENERGY SAVING IN THE GRID

Thank you for your attention!