Boost converter

Proceeding similar to the buck, the steps for this topology are 

The name given this zero is the RHP zero , as indicated earlier — to distinguish it from the well-behaved (conventional) left-half-plane zero. For the boost topology, its location can be found by setting the numerator of the transfer function above to zero, that is, s x (L/R) = 1. So the frequency location of the boost RHP zero is 

Note that the very existence of the RHP zero in the boost and buck-boost can be traced back to the fact that these are the only topologies where an actual LC post-filter doesn t exist on the output. Though, by using the canonical modeling technique, we have managed to create an effective LC post filter, the fact that in reality there is a switch/diode connected between the actual L and C of the topology, is what is ultimately responsible for creating the RHP zero. 

Line-to-output Transfer Function We know that 

---

The second family of converters are the boost-mode converters. The most elementary boost-mode (or boost-derived) converter can be seen in Figure 3-3. It is called a boost converter. 

Figure 3-4 Waveforms for a discontinuous-mode boost converter.

Figure 3-5 Waveforms for a continuous-mode boost converter.

Another form current-mode control is called hysteretic current-mode control. Here both the peak and the valley currents are controlled. This is obviously better for continuous-mode forward for boost converters. It is somewhat complicated to set-up, but it does offer very fast response times. It is not a very common method of control and its frequency varies. 

Figure 3-59 The major current loops within the major switching power supply topology types (a) the nonisolated buck converter (h) the nonisolated boost converter (c) the transformer-isolated converter.

Buck/Boost Converter Buck/Boost Converter... 

Figure 2-14 The Actual Implementation of the Input Routing Scheme of a Boost Converter...

Blog Entry 1 I thought a little harder on how zeners work, and realized that placing the zeners between the Vin rails will cause the zeners to melt if >12V was constantly supplied with a large Vin source, since Vin is not current regulated. Please don t flame [blame] me for the zener question I would still like to know how the Boost converter would react to overvoltaging. Perhaps that can answer whether zener diodes can even be used. 

Zverev, L, SiC Schottky Diodes Improve Boost Converter Performance, Power Electronics Technology, Vol. 29, Issue 3, March 2003, pp. 38-49. 

More sophisticated systems are able to remove charges from cells which have a higher voltage than the others and to bring them to cells which have a lower voltage in the series connection [58], Among the main converter topologies, the bidirectional nondissipative buck-boost converter [59,60] and the flyback converter [61,62] are the most studied. Active systems appear to be sophisticated circuits and thus may be expensive in relation to the cost of the cell they are intended to protect. 

We have thus derived the classical dc transfer function of a boost converter. 

A boost converter has an input range of 12 V to 15 V, a regulated output of 24 V, and a maximum load current of 2 A. What would be a reasonable goal for its inductance, if the switching frequency is a) 100 kHz, b) 200 kHz, and c) 1 MHz What is the peak current in each case And what is the energy-handling requirement ... 

Question 5 Why do we always get only up-conversion from a boost converter ... 

Question 30 Which end of a given input voltage range Vinmin to Vinmax should we pick for starting a design of a buck, a boost, or a buck-boost converter ... 

Similarly, the input current of a boost converter flows through the inductor at all times. 

The bond graph of a boost converter in Fig. 2.3 illustrates the use of these extended junctions. 

The previous chapters address various aspects of quantitative bond graph-based FDI and system mode identification for systems represented by a hybrid model. This chapter illustrates applications of the presented methods by means of a number of small case studies. The examples chosen are widely used switched power electronic systems. Various kinds of electronic power converters, e.g. buck- or boost converters, or DC to AC converters are used in a variety of applications such as DC power supplies for electronic equipment, battery chargers, motor drives, or high voltage direct current transmission line systems [1]. 

Clearly, a bond graph approach to FDI of systems modelled as a hybrid system is not limited to switched power electronic systems but may be applied to other engineering systems as well for which a hybrid model is appropriate. In the following, the case studies consider faults in a DC to DC boost-converter, in a three-phase DC to AC inverter and in a three-phase rectifier AC to DC. In some motor drives, a rectifier and an inverter are used back-to-back [8], Computations have been performed by means of the open source software program Scilab [21],... 

This chapter considers a simple boost converter often used in power electronic systems. Figure 8.1 depicts its circuit schematic. In this circuit, the MOSFET transistor and the diode may be considered non-ideal switches. The transistor is a controlled power switch. Boost converters are designed that they operate either in so-called continuous conduction mode or in discontinuous conduction mode. In continuous conduction mode the inductor current never falls to zero. Accordingly, the converter assumes two states per switching cycle. When the transistor is on, the diode is off and vice versa. The diode commutates autonomously and oppositely to the transistor. Hence, there are two system modes in a healthy boost converter. 

---