🔍 Key Concepts

• Identify the power flow in the block diagram: AC input → rectifier → DC link → inverter → AC motor • Know the difference between a direct AC‑to‑AC converter (no DC link) and an AC‑DC‑AC converter (with a DC link) • Recall how a controlled rectifier and an inverter/frequency controller are combined and what overall converter type that forms

💭 Think About

• Look at the labeled sections: what does the presence of a DC link between rectifier and inverter tell you about how the frequency and voltage are being changed? • Which of the answer choices normally uses a large DC link between stages, and which ones typically convert AC to AC directly without an intermediate DC stage? • Does the illustration show the output frequency being derived by chopping a DC voltage, or by directly reshaping the input AC waveform?

✅ Before You Answer

• Verify whether a DC link (with inductance) is characteristic of any of the answer choices • Check if a cycloconverter or synchroconverter would normally be drawn with a separate rectifier and inverter stages, or with a single stage of bidirectional switches from input to output • Confirm which option’s name best matches a system that clearly has a controlled rectifier plus an inverter/frequency controller feeding an AC synchronous motor