Kawalwa na Gwaji a Turbin da Duka ta Hanyar Chopper

Akwai

• Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

• Farkon Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

• Kammalwa na Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

Abubuwan Da A Samu:

• Bayanin Kudin Kwamfuta: Bayanin kudin kwamfuta yana nufin tsafta tsarin kwamfutan DC a cikin makinta na tsari don kawo shiga kyakkyawar da ita.

• Tattalin Da'aya: Tattalin da'ayin makinta na tsari da amfani da chopper yana iya zama ta hanyar gada voltaji da kuma kawo shiga shi a kan PWM signals don samun bayanin kwamfuta da ake bukata.

• Muhimmancin Chopper: Amfani da chopper don bayanin kudin kwamfuta yana ba da muhimmanci masu adadin daidai, sassan daidai, tsaftukan daidai, da kuma fadada daidai.

• Dukiyoyi a Cikin Tsarin Chopper: Dukiyoyi mai muhimmanci sun hada da MOSFET, pulse width modulation signal, rectifier, capacitor, inductor, da kuma abubuwan da suke sauti waɗanda suke samu MOV da fuse.

• Farkon Yakin: Farkon yakin za su iya haɗa da kontrollo na doka mai karɓi don tare da mazauna da dabara, da kuma abubuwan da suke sauti masu daidai don inganta kyakkyawan da kuma yaɗuwar tattalin jiki.

Makinta na tsari yana daya daga cikin abubuwan da ake amfani da su a matsayin yanayin kasa, da kuma tsaftukan daidai, da kuma inganta power factor correction. Power factor yana kontrollo a kan tsaftukan daidai. Wannan raka yana nuna yadda ake iya kontrollo kudin kwamfuta a cikin makinta na tsari daidai.

An samu nasarorin wuya da kula da sabbin metoda na kudin kwamfuta na DC saboda slip rings, brushes, da commutators, musamman idan alternator ratings yana zama daidai. Tsarin kudin kwamfuta na zamani sun yi aiki don kawo nasarorin wadannan abubuwa ta hanyar kadan cikin sliding contacts da brushes.

Wannan al'adu yana ba da farkon yakin da ke samu da amfani da chopper. Tsarin zamani sun amfani da semiconductor switching devices kamar diode, thyristors da transistors. A cikin electronics na kasa, ana iya tattara adadin daidai na energy na electrical, AC/DC converters sun fi sani a matsayin abubuwan da ake amfani da su.

Tsari na adadin daidai yana tafi daga tens zuwa hundreds watts. A kasuwanci, wani amfani da take da yawa shine variable speed drive don kontrollo tsarin induction motor. Tsarin tattarwa na energy sun kategorize a kan input da output power types.

• AC to DC (rectifier)

• DC to AC (inverter)

• DC to AC (DC to DC converter)

• AC to AC (AC to AC converter)

Yana da ayyuka da yanayin daidai da kuma abubuwan da suke sauti don tattara, tattara, da amfani da adadin daidai na electrical power. DC-DC converter yana daya daga cikin yanayin da ake amfani da su don tattara source of direct current from one voltage level zuwa level na biyu.

Muhimmancin power electronic converters sun haɗa da kowane:

• Adadin daidai masu daidai saboda adadin daidai na loss a cikin power semiconductor devices.

• Kyakkyawan daidai na system na power electronic converter.

• Tsari mai yau da kula da kula saboda bane da dukiyoyi masu yau.

• Tsaftukan daidai.

• Fadada daidai musamman idan a yi karshe da electromechanical converter system.

Akwai kuma wasu abubuwan da suke so kuɗi a cikin power electronic converters kamar haka-

• Circuit a cikin system na power electronic sun fi son harmonics a cikin supply system da kuma load circuit.

• AC to  DC and DC to AC converter sun yi aiki a cikin low input power factor under certain operating condition.

• Regeneration of power is difficult in power electronic converter system.

A cikin wannan project, an kontrollo average voltage across the field of a synchronous machine using a boost chopper. A boost chopper yana daya daga cikin DC to DC converter that provides a higher controlled output voltage from a fixed input DC voltage.

MOSFET yana daya daga cikin abubuwan da ake amfani da su don kontrollo switch (a switch whose turn on and turn off both can be controlled). MOSFET is used as the switching device in this Boost chopper circuit. The gate terminal of MOSFET is driven by a pulse width modulation (PWM) signal. Which is generated by using a microcontroller. The supply voltage of the chopper has been taken from a diode bridge rectifier by conversion of single phase AC/DC.

This scheme of field excitation control is extremely efficient and compact sized, due to the involvement of power-electronic circuitry. In many industrial applications, such as reactive power control, power factor improvement of transmission line it’s required to change field excitation.

This drive take power from fixed DC source and convert it to variable DC voltage. Chopper systems offer smooth control, high efficiency, faster response and regeneration facility. Basically a Chopper may be considered as DC equivalent of an AC transformer since they behave in an identical manner. As chopper involves one stage conversion, these are more efficient.

Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

To understand details of project plan let’s consider this block diagram below:

From the above diagram we can say that for 230V input of a full wave rectifier the output voltage is 146 (Approx.) the field voltage of the machine is 180V so we have to step up the voltage though the step up chopper. Now the adjusted DC voltage is fed to the field of the synchronous machine. The output voltage of the chopper can be varied by changing the duty cycle to do so we have to make a pulse generator of adjustable pulse width, and this can be done with help of a Microcontroller.

In microcontroller by comparing a random sequence signal with a constant magnitude we can generate a pulse signal but to avoid loading effect it’s advisable an electrical isolation to do this we are using an Opto coupler. A capacitor has been used in the chopper circuit in order to remove the ripple from the output voltage. It has been simulated that the inductor which has been used in the chopper circuit should be capable of handling 2-3 A of current during the short circuit period. Apart from the desired output voltage, we should also design the circuit so that it can withstand any fault condition.

• For  overvoltage protection, we will use a metal oxide varistors (MOV) whose resistance depends upon the voltage.

• For  overcurrent protection, we can use first acting current limiting Fuse.

To improve the quality of the waveform we can use filter circuit basically L or LC filter at the output of the bridge rectifier. The diode which has been should have less reverse recovery time here we can use fast recovery diode.

Values of circuit components that have been used

Input DC Voltage = 100V
Pulse voltage = 10V, Duty = 40%
Chopping frequency = 10 KHz
R = 225 ohm (As calculated from the machine rating)
L = 10mH
C = 1pF

Data obtained from the output
Output voltage: 174 V (Average)
Load current: 0.775 A (Average)
Source current: 0.977 A

Farkon Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

There is still much room for future development that would enhance the system and increase its business value.

Closed loop control

Application areas where the user deals with variable load, needs a closed loop control scheme to maintain constant excitation. Reference voltage and actual output voltage will be compared first and an error signal is generated. This error signal will decide the duty cycle of the chopper.

Reduction in temperature effect

Use of precision capacitor, switching diode can definitely improve the performance, but they will aid to the cost of the project.

Kammalwa na Tattalin Da'ayin Makinta na Tsari da Amfani da Chopper

In our project, we designed and implemented a low-cost and user-friendly excitation controller using Chopper. The target users of the system are industries requiring smooth, efficient and small controller which gives a wide range of voltage variation. This type of project is really useful in the industrial fields of developing countries like India, where energy crisis is a great concern.

We have learned much through the project. We got the lesson of team work, co-ordination, leadership while going through various phases of development of the project. We were challenged by the complexity of the technologies needed to build the system. This helped us to co-relate and apply the theoretical knowledge we obtained in engineering course.

None of us had experience with electronic control of motor before the project. We needed to learn different concepts and techniques quickly and apply them in the system. The project also provided a chance for us to accumulate experience in pulse signal generation and power MOSFET control area. This project experience has greatly enriched our knowledge and sharpened our technical skills.