1. DOUBLE INPUT Z-SOURCE DC-DC CONVERTER
Presented by

2. ABSTRACT
In this project presents a dynamic voltage restorer (DVR) that is characterized by the use of a high-frequency unidirectional isolated dc–dc converter is proposed. A traditional DVR has a large and bulky series transformer even for three-phase low-voltage up to 480-V applications because the transformer operates at the line frequency. This project discusses the control and performance of a low-voltage DVR using a high-frequency isolated dc–dc converter. The high-frequency transformer in the dc–dc converter is much smaller. Experimental results obtained from the prototype confirm the viability and effectiveness of the system configuration.

3. BLOCK DIAGRAM TMS PROCESSOR 5V DC SUPPLY 12V DC SUPPLY AC SUPPLY
DRIVER CIRCUIT
AC SUPPLY
RECTIFIER AND FILTER
Z SOURCE INVERTER
LOAD

4. BLOCK DIAGRAM EXPLANATIONS
Input supply:-Solar energy
BRIDGE RECTIFIER : It is Converted into AC TO DC Supply..
Filter: It is to remove unwanted frequency components from AC signal
Driver circuit:- It has two functions,
a) Amplification
b)Isolation.
It can be used to amplify the 5V pulses to 12V for using transistor technology and provided isolations for using optocoupler.
Pulse generator:- Here we have used PIC microcontroller(PIC 16F877A) to make a switching signal.
MULTILEVEL INVERTER : It can output ac voltage with the same dc power supply, which has a wider modulation index range than a traditional inverter.
Load:- AC load

5. Rectifiers
Here in our project for full wave rectification we use bridge rectifier.From the basic bridge configuration we see that two diodes(say D2 & D3) are conducting while the other two diodes (D1 & D4) are in off state during the period t = 0 to T/2.Accordingly for the negative cycle of the input the conducting diodes are D1 & D4 .Thus the polarity across the load is the same

6. filter
In order to obtain a dc voltage of 0 Hz, we have to use a low pass filter. So that a capacitive filter circuit is used where a capacitor is connected at the rectifier output& a dc is obtained across it. The filtered waveform is essentially a dc voltage with negligible ripples & it is ultimately fed to the load.

7. Power Supply Circuit

8. Driver Unit

9. Why Driver Circuit?
This driver circuit, which produces amplified, pulses for the Mosfet’s power circuit, which uses emitter coupled amplifier circuit to boost the triggering pulse low voltage to the high voltage.

10. Advantages
It is used to provide 9 to 20 volts to switch the MOSFET Switches of the inverter. Driver amplifies the voltage from microcontroller which is 5volts. Also it has an optocoupler for isolating purpose. So damage to MOSFET is prevented.

11. CIRCUIT DIAGRAM

12. EQUIVALENT CIRCUIT

14. CIRCUIT EXPLANATION
State 1, both source 1 and source 2 are active shows equivalent circuit of this state. When both source1 and source 2 are active, the converter input dc voltage is sum of voltage of two series dc sources. In this state, because both two sources are active, D1 and D2 are forward biased and D3 and D4 are reverse biased. Thus the sources current enters in Z-network through D1 and D2 and after passing load impedance, comes back into sources through negative polarity. State 2, source 1 is active and source 2 is inactive In this state, source 1 is active, so only this source provides converter (consequently load) energy. Because of source 1 is active then D1 is forward biased and D3 is reverse biased, so Current follows from D1 to Z-network to load.

15. State 3, source 1 is inactive and source 2 is active If source 1 is eliminated for each reason and source 2 is active, the converter can operate normally without effect of source 1 elimination.In state 3, it’s only source 2 that supplies converter and load. Source 2 activation causes forward bias of D2 and reverse bias of D4. Because of source 1 disconnection, current passes through D3 and indeed, current turns it on forcedly to complete current path. In this state, converter input dc voltage is only provided by source 2. State 4, both source 1 and source 2 are inactive Basically, this state is only following of one of the previously mentioned three states. Because in this state both dc sources are inactive and disconnected from converter, D1 and D2 are forcedly turned off and consequently, the only existing path for remain current, from previous state, is provided by D3 and D4. Thereupon, in state4 D3 and D4 are turned on.

16. Power supply
The power supply model consists of the 230V supply which is to be rectified and fed to the converter. To perform this operation we go for the diode bridge rectifier with capacitors.

17. Power Supply Circuit For Microcontroller
POWER SUPPLY FOR MICROCONTROLLER
Power Supply Circuit For Microcontroller

18. Microcontroller
PIC16F877A

19. +5V SUPPLY UNIT OPERATION
Initially 230 V AC supply is reduced to (0-9V) with the help of a step down transformer having a capacity of 500mA.
Since the input voltage to the regulator IC should be more than its output voltage, transformer secondary voltage is 9V.
This low voltage is rectified with the help of bridge rectifier. The ripples are minimized with the help of capacitor filter to get a smooth DC supply. The rating of the chosen capacitor filter is 1000µF.
+5V SUPPLY UNIT OPERATION

20. OPERATION CONT.,
The regulated DC voltage is obtained by using a regulator IC In the case of IC 7805, the unregulated DC voltage is applied to Pin 1, and the output is taken at Pin 3 and Pin 2 is grounded.
Another capacitor filter of rating 10µF is connected at the output of regulator IC to eliminate the voltage oscillations at the output due to the large voltage oscillations at the input of the regulator.

21. PIN Diagram

22. Features & Description of Regulators
Output Current up to 1A
Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V
Thermal Overload Protection
Short Circuit Protection
Output Transistor Safe Operating Area Protection

23. RECTIFIER
A rectifier is a device which offers a low resistance to the current in one direction and a high resistance in the opposite direction.
Such a device is  capable of converting A.C. voltage into a pulsating D.C. voltage.
The rectifier employs one or more diodes. It may be either a vacuum diode or a semiconductor diode.
There are two types
Half wave rectifier
Full wave rectifier
Bridge rectifier

24. BRIDGE RECTIFIER
Bridge rectifier is a full wave rectifier. It consists of four diodes , arranged in the form of a bridge .
It utilizes the advantages of the full wave rectifier and at the same time it eliminates the need for a centre tapped transformer.
The supply input and the rectified output are the two diagonally opposite terminals of the bridge.

25. BRIDGE RECTIFIER CONT.,
During the positive half cycle, the secondary terminal A is positive with respect to terminal B.
Now the diodes D1 and D3 are forward biased and hence do not conduct.
The current flows from terminal A to terminal B through D1, load resistance RL and the diode D3 and then through the secondary of the transformer.

26. BRIDGE RECTIFIER CONT.,
During the negative half cycle, terminal B is positive with respect to point A.
Now diodes D2 and D4 are forward biased and hence conduct.
Diode D1 and D3 are reversed biased and hence do not conduct.
The current flows from terminal B to terminal A through diode D2, the load resistance RL and diode D4 and then through the secondary of the transformer.

27. BRIDGE RECTIFIER CONT.,
On both positive and negative half cycles of the A.C. input, the current flows through the load resistance RL in the same direction.
The polarity of the voltage developed across RL is such that the end connected to the junction of the diodes D1 and D2 will be positive.

29. FEATURES OF PIC16F877A High-Performance RISC CPU
Lead-free; RoHS-compliant
Operating speed: 20 MHz, 200 ns instruction cycle
Operating voltage: V
Industrial temperature range (-40° to +85°C)
15 Interrupt Sources
35 single-word instructions
All single-cycle instructions except for program branches (two-cycle)

30. Special Microcontroller Features
Flash Memory: 14.3 Kbytes (8192 words)
Data SRAM: 368 bytes
Data EEPROM: 256 bytes
Self-reprogrammable under software control
In-Circuit Serial Programming via two pins (5V)
Watchdog Timer with on-chip RC oscillator
Programmable code protection
Power-saving Sleep mode
Selectable oscillator options
In-Circuit Debug via two pins

31. ADVANTAGES
The 16F877A is one of the most popular PIC microcontrollers and it's easy to see why - it comes in a 40 pin DIP pinout and it has many internal peripherals.  The 40 pins make it easier to use the peripherals as the functions are spread out over the pins.  This makes it easier to decide what external devices to attach without worrying too much if there enough pins to do the job.   One of the main advantages is that each pin is only shared between two or three functions so its easier to decide what the pin function (other devices have up to 5 functions for a pin).

32. BUFFER IC –CD4050
The CD4050BC hex buffers are monolithic complementary MOS (CMOS) integrated circuits constructed with N- and P-channel enhancement mode transistors. These devices feature logic level conversion using only one supply voltage (VDD). The input signal high level (VIH) can exceed the VDD supply voltage when these devices are used for logic level conversions. These devices are intended for use as hex buffers, CMOS to DTL/ TTL converters, or as CMOS current drivers, and at VDD = 5.0V, they can drive directly two DTL/TTL loads over the full operating temperature range.

33. Connection Diagrams

34. Features Wide supply voltage range: 3.0V to 15V
Direct drive to 2 TTL loads at 5.0V over full temperature range
High source and sink current capability
Special input protection permits input voltages greater than VDD

35. Absolute Maximum Ratings
Supply Voltage (VDD) -0.5V to +18V
Input Voltage (VIN) -0.5V to +18V
Voltage at Any Output Pin (VOUT) -0.5V to VDD + 0.5V
Storage Temperature Range (TS) -65°C to +150°C
Power Dissipation (PD)
Dual-In-Line 700 mW
Small Outline 500 mW
Lead Temperature (TL)
(Soldering, 10 seconds) 260°C

36. Applications CMOS hex inverter/buffer • CMOS to DTL/TTL hex converter
• CMOS current “sink” or “source” driver
• CMOS HIGH-to-LOW logic level converter.

37. Transistor as an amplifier.
The above common emitter amplifier is designed so that a small change in voltage in (Vin) changes the small current through the base of the transistor and the transistor's current amplification combined with the properties of the circuit mean that small swings in Vin produce large changes in Vout.
It is important that the operating parameters of the transistor are chosen and the circuit designed such that as far as possible the transistor operates within a linear portion of the graph, such as that shown between A and B, otherwise the output signal will suffer distortion.
Various configurations of single transistor amplifier are possible, with some providing current gain, some voltage gain, and some both.

38. Conti-----
From mobile phones to televisions, vast numbers of products include amplifiers for sound reproduction, radio transmission, and signal processing. The first discrete transistor audio amplifiers barely supplied a few hundred milliwatts, but power and audio fidelity gradually increased as better transistors became available and amplifier architecture evolved.

39. gENERAL DESCRIPTION  
in our project we use transistor in driver circuit. the transistor is used to amplify the signal pulse coming from the microcontroller circuit .Here we use two main types of transistor namely
CK100
2N2222
These two transistors are present in the driver circuit which is connected in a darlington pair circuit

40. darlington pair circuit

41. cont
In electronics, the Darlington transistor (often called a Darlington pair) is a compound structure consisting of two bipolar transistors (either integrated or separated devices) connected in such a way that the current amplified by the first transistor is amplified further by the second one[1]. This configuration gives a much higher current gain (written β, hfe, or hFE) than each transistor taken separately and, in the case of integrated devices, can take less space than two individual transistors because they can use a shared collector. Integrated Darlington pairs come packaged in transistor-like integrated circuit packages
The Darlington configuration was invented by Bell Laboratories engineer Sidney Darlington in He patented the idea of having two or three transistors on a single chip (and sharing a single collector), but not that of an arbitrary number.

42. TRANSISTOR-2N2222

43. conti
The 2N2222, often referred to as the 'quad two' transistor, is a small, common NPN BJT transistor used for general purpose low-power amplifying or switching applications. It is designed for low to medium current, low power, medium voltage, and can operate at moderately high speeds. It was originally made in the TO-18 metal can as shown in the picture, but is more commonly available now in the cheaper TO-92 packaging, where it is known as the PN2222 or P2N2222.

44. FEATURES
High current (max. 800 mA)
· Low voltage (max. 40 V).

45. PINNING

46. PIC Microcontrollers I/O Pin counts Memory Size (bytes) Memory Type
6 – 17 pins
18 – 27 pins
28 – 44 pins
45 – 80 pins
0.5K – 1K
2K – 4K
8K – 16K
24K – 32K
48K – 64K
96K – 128K
Memory Type
Special Features
Flash
OTP
ROM
Nano Watt Technology
Motor Control
LCD
USB
KEELOQ
Radio Frequency

47. Hardware details

48. Pic controller

49. Driver unit

50. Pulse output

51. APPLICATIONS:
Industrial application
Power generation side

52. WORK TO BE DONE
Hardware demo

53. ADVANTAGES
Improved efficiency
Low switching losses
Low voltage stress

54. APPLICATION Industrial appliance improve the reliability.
Boosting feature of converter makes it proper for new energy applications.

55. CONCLUSION
In this project double input Z-source dc-dc converter is proposed. The operation principle, including the operation modes and steady-state analysis is explained in detail. The analysis and simulation results show the input dc sources can deliver power to the load individually or simultaneously, as failure of each input sources doesn’t disturb the other’s operation.
Two input sources can have different characteristics and voltage. Also, converter controls output power with only one active switch which can reduce cost and improve the reliability. Boosting feature of converter makes it proper for new energy applications

56. REFERENCES:
E. Milady and H. E. McKenna, “Power quality issues in a hybrid power system,” IEEE Trans. Ind. Appl., vol. 38, no. 3, pp , May/Jun  
F. Giraud and Z. M. Salameh, “Steady-state performance of a gridconnected rooftop hybrid wind-photovoltaic power system with battery storage,” IEEE Trans. Energy Convers., vol. 16, no. 1, pp. 1-7, Mar 2001.
Yaow-Ming Chen, Yuan-Chuan Liu, and Sheng- sien Lin, “DoubleInput PWM DC-DC Converter for High-/Low-Voltage Sources,” IEEE Trans. Ind. Electron., vol. 53, no. 5, October  
Yuan-Chuan Liu and Yaow-Ming Chen, “A systematic approach to synthesizing multi-input dc–dc converters” IEEE Trans. Power Electron., vol. 24, no. 1, January

57. Thank You