A simple approach to this problem would be to begin by deciding the voltage gain that you desire and then backtracking the steps followed while applying volt-sec balance on the inductor to obtain the voltages across the inductor in DTs and (1-D) Ts intervals. After deciding the inductor voltages in energy storage and energy releasing intervals, you can then arrange the switches, source and load so as to get the desired characteristics in the converter. This could be done in a number of ways and in fact you can choose the switches thereafter depending upon the current carrying capability and the voltage blocking capacity that is required based on your design.

visit the following link below:

Conference Paper Derivation of the buck-boost PWM DC-DC converter circuit topology.

https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7872494

https://core.ac.uk/download/pdf/53188154.pdf

Thanks for the answers Uzmah Javed Mohammed Bilal Danoune Adnan Majeed

Say I want to propose a new(not design an existing) ZVS buck converter for a charger from 300v to 60V of 1 KW capacity. For the purpose i will use a buck converter topology. To reduce the switching losses by resonance, I will have to add a resonance network(extra Inductors, capacitors, diodes). Now my question is how I will come up a with resonance network that is entirely new(not published before.).

I have read some papers and seen that the authors proposed new resonance network that increases the efficiency. But how they start their journey in finding the new networks?

Any new design that is proposed should aim at getting the maximum efficiency at a minimal cost .While designing a resonant converter as well the aim is to keep the circulating current losses in the resonant tank minimum (of course quite low in comparison to the switching transition losses that you are aiming to minimise) so that the overall system efficiency is improved. Also in order to maximize the power density and minimise the overall cost , you would want to use minimum additional components. A basic resonant tank circuit would require an inductor and a capacitor. So, its for you to figure out how efficiently you could fit in the basic resonant tank circuit in your converter topology so as to achieve a soft switching operation in your converter. You could even make use of stray inductance and capacitances(eg. Switch capacitance) present in your converter while designing the resonant tank circuit. I would suggest reading some basics of resonant converters (almost all the famous textbooks in power electronics have a chapter on resonant converters) and to go for an in depth literature survey around the topic before you begin designing your converter.

Uzmah Javed Thanks again for the helpful reply.

Quote, "So, its for you to figure out how efficiently you could fit in the basic resonant tank circuit in your converter topology so as to achieve a soft switching operation in your converter." - in that regard, is there any principle/process in proposing the new resonant network. I mean, various authors used complex resonant network comprised of inductors, capacitors and diodes[some used more and others used less components]. It bewilders me that how they are perfectly managing the flow of voltage and currents and achieving the ZVS/ZCS.

Are these the correct steps to follow:

1. Insert an entirely new[1 or more (L, C)+ diodes maybe] resonant network inside buck topology

2. Derive the newly formed mode equations

3. Justify the equation by arbitrary simulation

4. Use energy balance eqn to draw the voltage conversion ratio vs normalized frequency curve and find resonant switching range.

5. Justify the resonant switching from simulation. If verified then that resonant network is a new one.

Am I understanding it correctly?

@zubair In my knowledge you are following the right approach for design. This should work perfectly provided the resonant tank is oscillating at the right frequency and at that the oscillations are synchronised properly with the transition intervals. But since you are working on topology development , this would require a lot of patience. Wishing you all the luck throughout the process!