Electrical Energy Saving Tips

Electrical energy has become the primary need for the universe. Electricity is an important resource for industrial and agricultural aspects. It plays a vital role in improving the quality of life. Electrical energy is generated by renewable as well as nonrenewable energy resources. The power generated at generating stations is stepped up to the somewhat level to decrease the transmission losses by the transformer. Then it is transmitted to the distribution substation from where it is distributed to the various consumers like industries, organizations, homes, etc

Since it is generated at a higher cost, and also day by day nonrenewable energy resources are depleting so there is a need to conserve these energy resources. In this article energy saving by voltage, an optimization technique is discussed and also some of the tips are given to save the electrical energy.

Energy-saving by Voltage Optimization

Reducing carbon emissions and electricity bill by using PWM technology

There are different voltage optimization products in the market but most of them are based on obsolete technologies like automatic tap switching transformer, electro-mechanical stabilizers, etc. In India, the UK and many other Asian countries the electricity supply is 230V +10% /-6% (216V – 253V) and the average voltage is usually 240V. Most of the electrical equipment is designed to work in 220V. If there is a 10% increase in the supply voltage, there will be a 15% to 20% more power consumption in the equipment. This will generate heat resulting in energy loss, CO2 emission, and will substantially reduce the life of the equipment.

The latest technology in voltage optimization is IGBT based PWM type Static Voltage Regulators / Static Voltage Stabilizers. This is an SMPS type voltage stabilizer for mains voltage where PWM is made directly in AC-to-AC switching, without any harmonic distortion. Pulse Width Modulation (PWM) is a commonly used technique for generally controlling DC power to an electrical device, made practical by modern electronic power switches. However, it also finds its place in AC choppers. The average value of current supplied to the load is controlled by the switch position and duration of its state. If the On period of the switch is longer compared to its off period, the load receives comparatively higher power. Thus the PWM switching frequency has to be faster. In this method, there is no AC to DC conversion and also change over it once again to AC output.

Advantages:

• Reduces the system design
• Decreases number of components
• Increases the efficiency and reliability

This disentangles the outline, decreases the segment tally and enhances proficiency and unwavering quality. The force stage is an IGBT chopper control.

The chopping frequency is around 20 kHz which ensures absolute silent operation and pure sine wave output. In the block diagram (top), the DSP based control circuit will give the PWM drive to the IGBT by sensing the AC output voltage. If the AC output voltage is more, the DSP will reduce the duty cycle of the PWM and if the AC output voltage is less, the DSP will increase the duty cycle of the PWM. When the input is above 220V, the output is maintained at 220V constant, +/-1%.

When the input is below 220V, the PWM duty cycle will be 100% so the output voltage is the same as the input. The second and third images show PWM and output WAVEFORMs (Black = PWM, Red = Output waveform). The figures show the PWM and the output waveforms. Note that the PWM frequency is not to scale. The actual PWM will be much denser. When the PWM duty cycle decreases, the AC output will decrease and when the PWM duty cycle increases the AC output will increase.

In the IGBT chopper, the IGBTs are connected in anti-series mode so it can switch in both directions. In this way AC to AC PWM is possible. During turn-off, another set of IGBTs will be turned on for freewheeling. So the fly-back energy will go back to the load. Because the PWM frequency is 20 kHz, a small amorphous or ferrite core inductor and a small filter capacitor are sufficient to integrate the chopped waveform to a pure sine wave.

In this, we do not use any transformers. Hence the stabilizer will be compact and light-weight. The same can be used for three-phase balancing and save further energy.

13 Tips to save energy at home

• Turn off lights in rooms when not in use and also during day time at which sufficient illumination is present.
• Use the Microwave ovens for short cooking times. It is also better to replace them with the solar-type of equipment.
• Put the air-conditioners in OFF mode particularly when you are out of the home. Close the doors and windows while running the air conditioning and while it is running don’t use ceiling fans.
• Due to high current consumption replace electric water heaters by natural gas water heaters and solar water heaters.
• Replace the Furnaces which are mainly inductive with the natural gas or other conventional heaters.
• Always put your personal computer or laptop in sleep mode while you’re not working on that and shutdown it when work is completed.
• Always use the automatic temperature control type of Iron boxes.
• Always use energy-efficient appliances like Fluorescent lamps, compact fluorescent lamps (CFL), LED lamps, etc instead of incandescent lamps and other more power drawing appliances. Also, use the sodium vapor lamps in place of mercury vapor lamps to save electricity.
• Use automatic turn off appliances when they are reached to a steady-state operating point.
• While dealing with the induction motors particularly induction types use the shunt capacitors across the terminals of motor to improve the power factor.
• Use the modern type of controller drives for industrial motors such as variable frequency drives (VFDs) will be the best option to save power particularly in the industrial sector and replace the motor generating sets with thyristor drives.
• Pumps also impact on energy saving in many of the chemical industries. Improper selection of impellers and other equipment leads to a waste of much energy. So select the pump according to the right capacity.
• Provide regular preventive maintenance to all machinery and equipment and replace them with new ones if necessary.