**2.2.4 Switch-mode rectifier**

The SMRs possess many categories in circuit topology and switching control approaches. A single-phase boost-type SMR is shown in Fig. 2(a), and the typical waveforms of *ac i* using low-frequency (LF) and high-frequency (HF) switchings are sketched in Figs. 2(b) and 2(c). The features of HF-SMR comparing to LF-SMR are: (i) more complicated in control; (ii) high control performances in line drawn current, power factor and output voltage; (iii) lower efficiency. More detailed survey for SMRs will be presented in the latter paragraphs.

Fig. 2. Boost-type SMR: (a) circuit; (b) sketched key waveforms for low-frequency switching; (c) sketched waveforms for high-frequency switching
