Interleaved Buck Converter Analysis

Abstract— In the conventional buck converter the supply current is discontinuous which may produce electromagnetic interference (EMI). In order to minimize the EMI problems an interleaved buck converter with continuous supply current has been introduced. Also due to the advantage of improved step-down conversion ratio, the interleaved buck converter can be used for high step-down and high frequency applications. The main features of the converter also include lower switch stress and lower output current ripple. The topology consists of two input capacitors which help in the reduction of the voltage stress across the switches. One-cycle control (OCC) technique is used to provide the switching pulses for the switches. The simulation has been
In [8], an interleaved buck converter using a coupled inductor is discussed. The size of the converter is reduced by replacing normal inductors by coupled inductors. But the main disadvantage of using coupled inductors is the presence of leakage inductance in the coupled inductors which may cause a huge voltage spike during transients. In [9], in order to extend the duty cycle of the interleaved converter two extra phase windings has been introduced. In order to minimize the voltage spike caused due to the leakage inductance an extra clamp circuit has also been added to the circuit. However, the complexity of the circuit is increased. A tapped inductor structure is described in [10]. By increasing the turns ratio of the tapped inductor, the duty cycle can be extended and the voltage stress experienced by the switch can be decreased. But in this topology also requires a clamp circuit in order to reduce the voltage spike during transients, this makes the circuit more complex. In [11], an interleaved topology is discussed in which zero voltage switching (ZVS) is achieved using an auxiliary switch, a diode and a coupled inductor. The main drawback of the circuit is that in order to achieve ZVS in one switch, a number of components have to be added to the circuit. In [12], ZVS is achieved in the switch using a transformer, thus the voltage stress is reduced. In this
In [17], a hysteretic controller which provides the required pulses for an interleaved converter with N number of phases is discussed. Fig. 2 shows the control pulse generation circuit, proposed in [17], for two and four interleaved phases.
In this paper, an interleaved buck converter with continuous supply current using OCC technique is introduced. The converter primarily consists of two input capacitors which help to reduce the semi-conductor voltage stress. The main advantage of the proposed converter is the continuous input current. Compared to the conventional IBC, the introduced converter also has an improved step-down conversion ratio. Due to the interleaved structure the output current ripple is also highly reduced. OCC technique is employed to provide the gate pulses which provide the benefit of faster transient response time.
The paper is arranged as follows: Section II describes the circuit configuration and the converter operation is explained in Section III. The control strategy employed is stated in Section IV. The simulation of the circuit along with the results is provided in Section V. Lastly, the conclusion is given in Section