2. Contents
1. INTRODUCTION
2. TECHNICAL BACKGROUND ON INVERTERS
3. OVER VIEW OF ADVANCED INVERTER
FUNCTIONS.
4. IMPACTS AND CHALLENGES OF ADVANCED
INVERTERS ADOPTION
5. ADVANCEMENT IN PV INVERTER
6. ADVANCEMENT IN AIR CONDITIONER
7. CONCLUSION
3. Introduction
Inverters are power electronics-based
devices which convert direct current (DC)
to an alternating current (AC).
Widely used in photovoltaic, wind turbine
generators and energy storage resources.
In these applications, inverters convert a
generated or stored DC to a precisely
modulated and grid synchronized AC
waveform.
4. Contd…
.
As DER (Distribution Energy Resources) become
incorporated onto the grid at higher penetration levels,
advances in inverter functionalities represent a
significant opportunity to improve the stability,
reliability, and efficiency of the electric power
distribution system.
5. Classification of inverter
Based on charging process
Power inverter
Solar inverter
Wind power inverter
Based on utility
Independent control inverter
Grid-connected inverter
Based on nature
Voltage source inverter
Current source inverter
6. Input voltage
A typical power inverter device or circuit requires a
relatively stable DC power source capable of
supplying enough current for the intended power
demands of the system. The input voltage depends on
the design and purpose of the inverter. Examples
include :
300 to 450 V DC, when power is from electric vehicle
battery packs in vehicle-to-grid systems.
Hundreds of thousands of volts, where the inverter is
part of a high voltage direct current power
transmission system
7. Contd…
12 V DC, for smaller consumer and
commercial inverters that typically run from a
rechargeable 12 V lead acid battery.
24 and 48 V DC, which are common
standards for home energy systems.
200 to 400 V DC, when power is from
photovoltaic solar panel.
8. Technical Background on Inverters
Standard Inverter Key Concepts:
• Fundamentally, an inverter is a device which converts a
direct current (DC) input to an alternating current (AC)
output.
• Inverters are used in a range of applications, including
consumer power electronics, electric vehicles, and
photovoltaic and energy storage interconnections to power
distribution systems at the primary (4 kV, 13.8 kV, 27 kV,
and 33 kV) and secondary (120/240 V, 120/208 V,
240/480 V) levels.
• In distribution applications, these devices produce a
sinusoidal waveform of the appropriate frequency.
9. Advancements in inverter
Forced commutated thyristor inverter (1933)
Three phase bridge inverter (1968)
Pulse width modulated inverter (1975)
PWM Z-source neutral point clamped inverter (1988)
Dual buck inverter with unified PWM (1989)
Current fed switched inverter (1990)
HIGH FREQUENCY LINK INVERTER (2001)
10. Overview of Advanced Inverter
Functions
Advanced Inverter Key Concepts
• An advanced inverter has the capacity
To supply or absorb reactive power
To control and modulate frequency and voltage
Induction heating
• As a flexible source and sink of both active and
reactive power, advanced inverters provide an
opportunity for the extensive control that enables
safety and reliability in DER applications.
11. Contd….
Capacitors could be installed to either supply
or absorb reactive power. Practical
limitations include:
Limited variability of reactive power that can be
supplied or absorbed dependent on the ability to switch
on/off various combinations of capacitors at a location.
Reactive power supplied or absorbed by capacitors will
greatly change with minor changes in voltage level.
12. Advanced Inverter Functionalities
Reactive Power Control:
The presence of inductive loads results in a phase
difference between voltage and current waveforms,
causing losses which reduce the efficiency of real power
distribution.
Less efficient power distribution requires greater
current, which magnifies the impact of line losses.
13.
14. Impacts & Challenges of Advanced Inverters
Adoption
Impacts:
• Reactive power control increases efficiency of power
distribution by reducing line losses.
• The voltage and frequency ride-through functionalities
provide dynamic grid support in the presence of a fault
along the interconnected line.
• Avoiding “unnecessary” disconnection, especially of
large distributed energy resources, could improve grid
reliability.
15. Contd…
Challenges:
There is ongoing work to develop interoperability
standards for DER devices including inverters and
inverter controllers. Therefore, limitations are there
to how much these advanced functionalities can be
used autonomously without impacting the grid or
other customers’ equipment .
Different safety requirements and standards are to be
implemented for residential and small commercial
applications.
16. Advancements in pv inverter
Over the last 40 years, solar panels are connected
together into strings and the DC power is wired to a
large inverter in a central location called string
inverter.
In 1996s, Micro inverter technology came into
existence, in which inverter installed behind each
solar module. All the inverters connected through bus
bar.
17. Advancements in air conditioner
• Compressor motor is driven by inverter to control its
speed.
• Inverter technology provides a more precise room
temperature without the temperature fluctuations.
• A microwave inverter is a system used in microwave
powering which uses inverter power supply as
opposed to traditional magnetic coils or
transformers. It is more efficient and powerful.
• Other applications include welding, HVDC, UPS,
LCD screen, Electric tasers, Hybrid vehicles etc
18. •A microwave inverter is a system used in microwave
powering which uses inverter power supply as opposed to
traditional magnetic coils or transformers. It is more
efficient and powerful.
19. Conclusion
• Advanced inverter is a simple but versatile
circuit.
• It is Extensively used as buffer in the output
stage to reduce the loading effect of the
previous stage.
•Advanced inverter functionalities may lend
significant improvement to the stability,
reliability, and efficiency, of the electric
power distribution system.
20. References
• M.Amirabadi,A. Balakrishnan, H.A.Toliyat, andW. C.
Alexander,“High frequency AC-link PV inverter,” IEEE
Trans. Ind. Electron., vol. 61,no.1,pp. 281–291, Jan. 2014.
•T. Kerekes, M. Liserre, R.Teodorescu, C. Klumpner, and M.
Sumner,“Evaluation of three-phase transformerless
photovoltaic inverter topologies,” IEEETrans. Power
Electron., vol. 24, no. 9, pp. 2202–22 Sep. 2009.
