idijoeteque11
Newbie level 4
Hello,
I have seen a few posts on here regarding whether the full bridge or half bridge circuit topology is best within a SMPS. However, not in regards to power density.
I am designing a power supply that requires a high step up (of 1:20) and must achieve the highest possible power density. Although FB is typically used in this domain, I have also recently seen some topologies for high step-up that use the HB, leading me to get thinking a bit more as to why.
My question is, if one was wishing to attain the highest power density, which would they choose as the main inverter bridge - the FB or the HB? One would assume the FB, because the HB presents half the input voltage to the transformer and thus it has to step up the voltage by an even larger margin. However, the addition of two extra switches means the requirement for extra gate drives, and larger heat sinks. Furthermore, if one was to use a resonant topology, there are smarter things that can be done with the half bridge to get high performance than with the full bridge, such as clamping etc.
Full bridge is usually used with high power, higher input current supplies - however mine is moderate power <1kW, and input current is not significant (<5A).
Therefore, although the obvious choice for me originally was the full bridge due to the step up aspect - I am now leaning towards possibly using the half bridge instead. Also oftentimes, when I see the HB, it seems to be switched at a much higher frequency than the FB - leading to reduced passives sizes etc.
I suppose the drawback of using the HB (lower output voltage) could be mitigated by boosting in a pre-converter, for e.g.
Your opinions on this matter are greatly appreciated! Thanks. opcorn:
I have seen a few posts on here regarding whether the full bridge or half bridge circuit topology is best within a SMPS. However, not in regards to power density.
I am designing a power supply that requires a high step up (of 1:20) and must achieve the highest possible power density. Although FB is typically used in this domain, I have also recently seen some topologies for high step-up that use the HB, leading me to get thinking a bit more as to why.
My question is, if one was wishing to attain the highest power density, which would they choose as the main inverter bridge - the FB or the HB? One would assume the FB, because the HB presents half the input voltage to the transformer and thus it has to step up the voltage by an even larger margin. However, the addition of two extra switches means the requirement for extra gate drives, and larger heat sinks. Furthermore, if one was to use a resonant topology, there are smarter things that can be done with the half bridge to get high performance than with the full bridge, such as clamping etc.
Full bridge is usually used with high power, higher input current supplies - however mine is moderate power <1kW, and input current is not significant (<5A).
Therefore, although the obvious choice for me originally was the full bridge due to the step up aspect - I am now leaning towards possibly using the half bridge instead. Also oftentimes, when I see the HB, it seems to be switched at a much higher frequency than the FB - leading to reduced passives sizes etc.
I suppose the drawback of using the HB (lower output voltage) could be mitigated by boosting in a pre-converter, for e.g.
Your opinions on this matter are greatly appreciated! Thanks. opcorn: