A bidirectional DC/DC converter is a multi
port, bidirectional, and variable topology power conversion device that can be
applied to various power electronic devices and new energy systems to provide
DC power. It can be used on both the input and output sides, with
characteristics such as multiple voltage levels, high power density, and wide
range of voltage and current regulation. Compared with single port converters,
the advantage of bidirectional DC/DC converters is that they can achieve
flexible configuration of system power and have better dynamic response and
higher reliability.
In high-power systems, bidirectional DC/DC
converters are usually used for bidirectional transmission of power flow, by
controlling the current flow direction to match the voltage at the input and
output terminals. Due to its ability to achieve voltage regulation on the
output side, it can achieve flexible configuration of power flow on the input
and output sides without affecting voltage accuracy. Due to the advantages of
large power capacity and good input/output characteristics of bidirectional
DC/DC converters.
1. Working principle
A bidirectional DC/DC converter generally consists of two
parts, namely a power converter and a control circuit. The power converter part
mainly completes power conversion, achieving the connection between the input
power supply and the load; The control circuit controls the flow of voltage and
current to match the input power supply.
2. Topology structure
In the topology structure of bidirectional DC/DC
converters, soft switching topology is the most common. In the topology
structure, the current source is in the forward conduction state of the switch,
and the switching off of the switch causes an increase in inductance current.
Due to the significant increase in inductance current, significant voltage
stress is generated on the inductance, so a higher switching frequency is
needed to reduce this stress. Due to the high reverse recovery loss generated
by high-frequency switching devices, it is necessary to use large capacitors
for energy storage to reduce reverse recovery loss. Due to its above
characteristics, this topology structure is widely used in high-frequency
high-power transformations.
3. Typical Applications
In situations where DC to DC conversion is required, a bidirectional
DC/DC converter can be used to convert the AC input of the mains power into DC
output, and a filtering capacitor can be connected at the input end according
to the load characteristics to keep the converter in a constant voltage working
state and feed back the input energy to the power grid. Other switching devices
or bidirectional switching devices can also be connected in series on the DC
bus to achieve DC-DC and AC-AC conversion.
4. Summary
With the development of power electronics
technology, bidirectional DC/DC converters are widely used in various power
electronic devices, such as photovoltaic power generation systems, battery
energy storage systems, fuel cell energy storage systems, electric vehicles,
etc.
The current topology structures used in
bidirectional DC/DC converters mainly include:Single level topology, two-level topology,
and multi-level topology.
In high-power systems, when the
input/output voltage of the bidirectional DC/DC converter used is of the same
voltage level, its boost ratio should not be too high, otherwise it will affect
the normal operation of electrical equipment and even cause damage to
electrical equipment due to inability to work properly. Therefore, in practical
engineering, it is necessary to choose a suitable bidirectional DC/DC converter
topology based on the actual situation. As a provider of new energy vehicle on-board
power supply solutions, Landworld is committed to providing users with more
support for bidirectional on-board power supply products.
Previous
Next
Return