Thyristor Operation in Inverters Quiz

The process of turning off a semiconductor device using an external circuit.

Forced commutation using an LC circuit tuned to the device's turn-off time.

A circuit with inductance (L) and capacitance (C) used for resonant commutation.

Forced commutation using a resistor (R) and a capacitor (C).

Forced commutation using an external voltage source to reverse bias the device.

Forced commutation by diverting current from the device using an external circuit.

Forcing a semiconductor device off by a gate pulse, commonly used in thyristors.

A type of inverter where commutating components are connected in series with the load.

A method of commutation where the load current decays to zero naturally, without forced switching.

Components (like inductors and capacitors) used to control the switching of devices in an inverter.

RLC circuit where oscillations naturally happen.

An inverter that uses resonant frequencies for commutation.

Inverter operates in three distinct phases: T1 on, both off, and T2 on.

Not a pure sine wave, has harmonics.

Distorted output, limited operating frequency, discontinuous current flow, high component ratings, and poor load regulation.

Series inverters where modifications are done to overcome limitations like output distortion and low operating frequency limits.

A series inverter with overlapping conduction periods of thyristors, enabling higher output frequencies.

A series inverter design where power is drawn from the DC supply in both half-cycles, improving DC source requirements.

An inverter type with commutating components in parallel with the load, suitable for low-frequency applications.

A capacitor used to switch current paths in an inverter, enabling thyristor turn-off.

When a thyristor is conducting, current flows through it.

Inductor part of the circuit, stores energy during the switching process.

The range of frequencies produced by an inverter.

Inverter circuit with components in series.

Inverter circuit with components connected in parallel with the load.

Turn-off of a device when the current/voltage naturally reverses, easing commutation.

A three-phase inverter conduction mode where each thyristor conducts for 180° of the output voltage waveform. Thyristor pairs are turned on in sequence with a 180° delay, resulting in a specific output voltage pattern.

The specific order in which thyristors in a three-phase inverter are triggered to control the output voltage waveform, creating a six-step output pattern.

In this operation, each device is in conduction state for 120° with a 60° interval between them. This method is suited for load connected in Delta form and results in a 6 steps waveform across the phase.

The waveform of the voltage produced at the output terminals of a three-phase inverter. It's based on the firing sequence of the thyristors and exhibits distinct steps and zero voltage durations.

An electronic circuit converts a DC input into a three-phase AC output, commonly used in adjustable-speed drives.

A type of inverter circuit that uses complementary voltage commutation, making it simpler and more affordable.

Simple design, small size, lower cost, better output voltage compared to series inverters, small commutating components.

Requires a large transformer at low frequency, needs additional feedback diodes for the commutating capacitor, not suitable for fluctuating loads, performance affected by large power.

Limited to a few kHz frequencies. Used for high current, low voltage applications; uninterruptable power supplies (UPS); creating square waveforms from dc.

A system using two independent circuits creating single-phase PWM voltage-sourced inverters.

Generates bipolar voltage (-200V or +200V). Harmonics are around the carrier frequency with a maximum at 1620Hz, a maximum of 103%.

Generates monopolar voltage waveform (0 to +400V, then 0 to -400V). Lower harmonics, smoother currents. Double the fundamental component magnitude compared to half-bridge.

Converts DC power to three-phase AC power, typically using six thyristors.

A change in the firing sequence of thyristors, with 60-degree intervals to synthesize a 360-degree AC output.

Large transformers are needed for parallel inverter circuits, especially at low frequencies.