**4.2 Input power clamp (IPC) method**

The input power clamp (IPC) method [19] is used for braking the electrical energy in a matrix converter motor drive. The IPC method requires only one braking resistor and a UDS, as shown in **Figure 10**, when compared to the BDS method, which requires three switches in series with three resistors. Electrical braking circuit or regeneration control circuit (RCC) for the input power clamp (IPC) method

**Figure 9.** *Bidirectional switch (BDS) method.*

**Figure 10.** *The input power clamp (IPC) method.*

is located across the input filter capacitors (*CAB*, *CBC*, and *CAC*). The RCC of IPC is controlled using either power comparison (PC) technique or the input voltage reference (IVR) technique.

The main power electronic components for RCC of IPC are conventional uncontrolled six-pulse rectifier and a UDS in series with a braking resistor (R), as shown in **Figure 10**. This braking resistor does not have inductive property to help to achieve better electrical braking when regeneration happens in MC drive. It is believed that IPC method is the best method when compared to BDS method because it requires only fewer power semiconductor switching components but not suitable for aerospace applications because it has electrolytic capacitor in the RCC.
