Motor Control

Load Commutated Chopper Circuit

Load Commutated Chopper Circuit: In this method of Load Commutated Chopper Circuit, the load current flowing through the thyristor is made to become zero while the motor current is conducted by the free-wheeling diode. Figure 10.36(a) shows the circuit of a Load Commutated Chopper. The thyristor pairs Th1Th2 and Th3Th4 alternatively conduct the load current. …

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What is TRIAC?

What is TRIAC? | Symbolic Representation | VI Characteristics of TRIAC: What is TRIAC? – The full form of TRIAC is Triode for Alternating Current (TRIAC) or Triode for AC. It is a bilateral switch with three terminals—anode, cathode and a single gate. It conducts in either direction being equivalent to two SCRs connected in …

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Types of Forced Commutation

Types of Forced Commutation: It was observed from the discussion on choppers and inverters that in thyristor systems fed from dc supply, the forward current does not pass through zero naturally and must therefore be forced to become zero at appropriate instants by means of auxiliary circuitry, called the commutation circuit. Apart from forcing the …

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What is PWM Inverter?

What is PWM Inverter?: What is PWM Inverter? – In presenting the arguments here attention will be focused on a single-phase inverter. Instead of the single rectangular pulse output of Figs 11.46 and 11.48 during each half-cycle, a commutation circuitry can be devised to produce a series of short duration pulses as output in each …

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Three Phase Bridge Inverter

Three Phase Bridge Inverter | Working Principle: The basic three phase bridge inverter is a six-step inverter. A step is defined as a change in the firing sequence. A 3-phase thyristor bridge-inverter is shown in Fig. 11.49. Th1 to Th6 are the six load-carrying thyristors while D1 to D6 are the free-wheeling diodes. Each pair …

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