Detailed Solution
- There is an instantaneous voltage difference at the DC terminals of the two converters
- It produces enormous circulating current between the converters and that will flow through the load.
- Therefore, in the practical dual converter, it is necessary to control the circulating current.
- The advantage of this scheme is that we can get smooth operation of the converter at the time of inversion.
What is the purpose of circulating current in a dual converter?
In a dual converter, the circulating current allows smooth reversal of load current with improved speed of response The circulating current helps in maintaining continuous conduction of both the converters irrespective of load and the time response to change the operation from one quadrant to other is faster.
What happens when two converters are out of phase?
Since the instantaneous output voltages of two converters are out of phase, there will be an instantaneous voltage difference and this will result In circulating current between two converters. This circulating current will not flow through the load and is normally limited by circulating current reactor L 1 as shown in Fig. 1.
What happens when two full converters are connected back to back?
If two full converters are connected back to back as shown in Fig. 1 both the output voltage and load current flow can be reversed. The system will provide four quadrant operation and is called as dual converter. Dual converters are normally used in high power variable speed drives.
Do I need a reactor between the two converters?
Considering a dual converter operating without circulating current, the AC current is barred from flowing by controlled firing pulses. This ensures that the converter carrying the load current conducts while the other converter is blocked. This means that a reactor between the converters is not needed.
What is dual converter?
What are the two types of dual converters?
What is ideal output voltage?
What is the firing angle of a converter 2?
How many converters can be used at a time?
What is a three phase rectifier?
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What are the advantages of circulating current mode of single phase dual converter?
It produces enormous circulating current between the converters and that will flow through the load. Therefore, in the practical dual converter, it is necessary to control the circulating current. The advantage of this scheme is that we can get smooth operation of the converter at the time of inversion.
How does a dual converter work?
Dual Converter is an Electronic Device or Circuit made by the combination of two bridges. One of them works as Rectifier(Converts A.C. to D.C.) and other bridge works as Inverter(converts D.C. into A.C.). Thus an electronic circuit or device in which two processes take place at same time, is known as Dual Converter.
What is non-circulating current mode?
Non-Circulating Current Mode: The circulating current does exist in both the converter circuits, but it is avoided by using a reactor in non-circulating type and by operating only one circuit in case of circulating type. During the converter 1 operation, firing angle (α1) will be 0 < α1 < 90o; Vdc and Idc are positive.
What is a dual converter explain the principle of operation of a dual converter in a circulating current mode how the same is used for speed control of dc drive?
In a dual converter, two converters are connected together back to back. One of the bridge works as a rectifier (converts AC to DC), another half bridge works as an inverter (converts DC to AC) and connected commonly to a DC load.
What happens if there is no circulating current in dual converter?
1) Dual Converter Operation without Circulating Current In this type of dual converter, only one converter is in conduction and another converter is temporarily blocked. So, at a time one converter operates and the reactor is not required between the converters.
What is the ideal condition for dual converter?
Ideal Dual Converter The firing angles must be properly controlled here so that the average output voltage of the two converters must have the same magnitude and polarity. To attain this condition, out of the two, one converter must act as a rectifier while another as inverter.
What are the two models of dual converter control?
Here, three-phase rectifier and three-phase inverter are used. The processes are similar to single-phase dual converter. The three-phase rectifier will do the conversion of the three-phase AC supply to the DC. This DC is filtered and given to the input of the second converter.
What is the major advantage of using dual converters?
Explanation: Dual converters provide four quadrent operation, which means voltage can be positive or negative and so can be the current.
What is dual converter controlled drive?
Dual converters are commonly used to operate the dc drives where the four-quadrant operation needed. Two back to back connected full controlled converters are called as dual converter. One of the converter works as a ac to dc converter and the other one works as a dc to ac converter.
What is the difference between full converter and dual converter?
Full wave rectifiers have three configurations - fully controlled, semi controlled and uncontrolled. Fully controlled config has 4 SCRs, semi controlled config has 2 SCRs and 2 diodes and uncontrolled config has 4 diodes. SCRs make the control over the output voltage possible (by controlling the firing angle).
What is the addition of the firing angle of rectifier A & B in dual converter?
The firing angles are adjusted such that. Firing angle of converter 1 (α 1) + firing angle of converter 2 (α 2) = 180° Converter 1 as rectifier when 0° < α 1 < 90° and converter 2 as inverter when 90° < α 2 < 180°
What will required for four quadrant dual operation?
Detailed Solution. The full converter is operated in two quadrants hence to obtain four-quadrant operation the drive requires another two quadrants; this will be obtained by reversal of current. The reversal of current can be done by connecting two full converters back to back.
What are the disadvantages of dual converter?
The dual conversion uses two local oscillators in the circuit, the circuit can act as power hungry due to extra matching required. Hence, modern receivers tends to avoid this kind of structure for receivers.
What is the difference between converter and dual converter?
Single Phase Dual Converter The input is given to the converter 1 which converts the AC to DC by the method of rectification. It is then given to the load after filtering. Then, this DC is provided to the converter 2 as input. This converter performs as inverter and converts this DC to AC.
What is the major advantage of using dual converters?
Explanation: Dual converters provide four quadrent operation, which means voltage can be positive or negative and so can be the current.
What is the difference between full converter and dual converter?
Full wave rectifiers have three configurations - fully controlled, semi controlled and uncontrolled. Fully controlled config has 4 SCRs, semi controlled config has 2 SCRs and 2 diodes and uncontrolled config has 4 diodes. SCRs make the control over the output voltage possible (by controlling the firing angle).
Single Phase Dual Converter | PDF | Direct Current | Rectifier - Scribd
A.D. PATEL INSTITUTE OF TECHNOLOGY. Subject :ELECTIRCAL DRIVES (2160910) Topic: SINGLE PHASE DUAL CONVERTER. Prepared by: KHICHADA BHAVIN(140013109005) Guided by: HARDIK SIR Contents Introduction Principle of Dual Converter Circuit Diagram Waveform Non-Circulating Current Mode of Operation Circulating Current Mode Of Operation Advantage Disadvantage Reference ...
Three phase dual converter drive - ECSTUFF4U
The schematic diagram of three phases dual converter d drive as shown in the figure. As per the circuit diagram converter, 1 allows motor control 1 and 4 quadrants whereas with converter 2 the operation in 2 and 3 quadrants obtained
Power Electronics - Dual Converters - tutorialspoint.com
Power Electronics - Dual Converters, Dual converters are mainly found in variable speed drives (VFDs). In a dual converter, two converters are linked together back to back. The operation of a dual
Electrical Seminar Report on Three Phase Dual Converter - 1000 Projects
Introduction to Three Phase Dual Converter Seminar Topic: For power conversion from ac to dc in industries thyristor based three phase controlled rectifiers which offers a reliable conversion and have a long life time.
What is dual converter?
Dual converter, the name itself says two converters. It is really an electronic converter or circuit which comprises of two converters. One will perform as a rectifier and the other will perform as an inverter. Therefore, we can say that double processes will occur at a moment.
What are the two types of dual converters?
They are of two types: Single-phase dual converter and three-phase dual converter.
What is ideal output voltage?
The term ‘ideal’ refers to the ripple free output voltage. For the purpose of unidirectional flow of DC current, two diodes (D 1 and D 2) are incorporated between the converters. However, the direction of current can be in any way. The average output voltage of the converter 1 is V 01 and converter 2 is V 02. To make the output voltage of the two converters in same polarity and magnitude, the firing angles of the thyristors have to be controlled.#N#Average output voltage of Single-phase converter =#N#Average output voltage of Three-phase converter =#N#For converter 1, the average output voltage,#N#For converter 2, the average output voltage,#N#Output voltage,#N#The firing angle can never be greater than 180 o. So,
What is the firing angle of a converter 2?
During the converter 2 operation, firing angle (α 2) will be 0<α 2 < 90 o; V dc and I dc are negative.
How many converters can be used at a time?
One converter will perform at a time. So there is no circulating current between the converters.
What is a three phase rectifier?
The processes are similar to single-phase dual converter. The three-phase rectifier will do the conversion of the three-phase AC supply to the DC. This DC is filtered and given to the input of the second converter. It will do the DC to AC conversion and the output that we get is the three-phase AC. Applications where the output is up to 2 megawatts. The circuit is shown below.
What is a dual converter?
Dual converters are mainly found in variable speed drives V F D s. In a dual converter, two converters are linked together back to back. The operation of a dual converter is explained using the diagram below. It is assumed that −
Which diodes show unidirectional flow?
Diodes D1 and D2 show the unidirectional flow of current.
How does a simple charger work?
Simple chargers − Operates by supplying a constant DC power source into the battery being charged.
What is an inductive charger?
Inductive chargers − Uses electromagnetic induction to charge the battery. Intelligent chargers − Used to charge a battery that contains a chip that communicates with the smart charger. Motion powered charger − Makes use of human motion to charge a battery.
What is the back to back connection of two fully controlled converters across the load circuit?
The back to back connection of two fully controlled converters across the load circuit is named as Dual converter. The single phase full converters allow only two quadrant operation with inductive loads to extent the operation to four quadrant the dual converters are used (Fig. 2).
What is dual converter?
The system will provide four quadrant operation and is called as dual converter. Dual converters are normally used in high power variable speed drives. If α 1 and α 2 are the delay angles of converters 1 and 2 respectively, the corresponding average output voltages are V o1 and V o2.
What happens when two converters are out of phase?
Since the instantaneous output voltages of two converters are out of phase, there will be an instantaneous voltage difference and this will result In circulating current between two converters . This circulating current will not flow through the load and is normally limited by circulating current reactor L 1 as shown in Fig. 1.
Can a dual converter be operated with or without circulating current?
The dual converters can be operated with or without circulating current, only one converter operates at a time. When circulating current is not present however, Other converter is completely blocked by inhibiting gate pulses.
Maximum circulating current Solution
Peak input voltage - Peak input voltage is the peak value of the sinusoidal input voltage V m sin (wt) to the converter. (Measured in Volt)
What causes circulating current in dual converters?
Circulating current is dual converters are caused by the out of phase voltages from both the converters. If only one converter is performing at a time, then the circulating current is not present. The circulating current is present only when both the converters are working at the same time.
How to Calculate Maximum circulating current?
Maximum circulating current calculator uses maximum_circulating_current = (2*Peak input voltage* (1- (cos(Delay angle of first converter)))/ (Angular frequency in radians/sec*Circulating current reactor)) to calculate the Maximum circulating current, The Maximum circulating current formula is the maximum value of the circulating current of the dual converter.
What is dual converter?
Dual converter, the name itself says two converters. It is really an electronic converter or circuit which comprises of two converters. One will perform as a rectifier and the other will perform as an inverter. Therefore, we can say that double processes will occur at a moment.
What are the two types of dual converters?
They are of two types: Single-phase dual converter and three-phase dual converter.
What is ideal output voltage?
The term ‘ideal’ refers to the ripple free output voltage. For the purpose of unidirectional flow of DC current, two diodes (D 1 and D 2) are incorporated between the converters. However, the direction of current can be in any way. The average output voltage of the converter 1 is V 01 and converter 2 is V 02. To make the output voltage of the two converters in same polarity and magnitude, the firing angles of the thyristors have to be controlled.#N#Average output voltage of Single-phase converter =#N#Average output voltage of Three-phase converter =#N#For converter 1, the average output voltage,#N#For converter 2, the average output voltage,#N#Output voltage,#N#The firing angle can never be greater than 180 o. So,
What is the firing angle of a converter 2?
During the converter 2 operation, firing angle (α 2) will be 0<α 2 < 90 o; V dc and I dc are negative.
How many converters can be used at a time?
One converter will perform at a time. So there is no circulating current between the converters.
What is a three phase rectifier?
The processes are similar to single-phase dual converter. The three-phase rectifier will do the conversion of the three-phase AC supply to the DC. This DC is filtered and given to the input of the second converter. It will do the DC to AC conversion and the output that we get is the three-phase AC. Applications where the output is up to 2 megawatts. The circuit is shown below.