Explain the principle of a bidirectional active-clamped (AC) flyback converter.
1 Answer
A bidirectional active-clamped (AC) flyback converter is a type of power electronic circuit used for bidirectional power flow between two different voltage sources. It combines the principles of a flyback converter and an active clamp circuit to achieve bidirectional power transfer efficiently and effectively. The converter can function in both forward and reverse modes, allowing power flow in either direction.
The main principle of a bidirectional AC flyback converter involves the use of two power switches (usually MOSFETs) and an active clamp circuit to control the voltage and current flow during both power delivery and power regeneration phases. Here's a step-by-step explanation of the operating principle:
Power Delivery Mode:
When power needs to be delivered from the input source (e.g., a battery or a DC power supply) to the output source (e.g., a load or another battery), the converter operates in the forward mode.
The first power switch (S1) is turned on, connecting the input voltage source to the primary side of the flyback transformer.
Energy is stored in the transformer's primary winding during the switch-on period.
The primary current ramps up, storing energy in the transformer's core.
When the first switch (S1) turns off, the energy stored in the transformer's core causes the voltage to spike.
The active clamp circuit, which consists of a second power switch (S2) and a clamp capacitor, comes into play here.
The second switch (S2) is turned on, creating a closed loop for the energy stored in the transformer's leakage inductance to circulate through the clamp capacitor.
The active clamp circuit absorbs the energy, limiting the voltage spike and protecting the switches from excessive voltage stresses.
Power Regeneration Mode:
When power needs to be regenerated or transferred back from the output source to the input source (e.g., during regenerative braking in an electric vehicle or energy recovery in a renewable energy system), the converter operates in the reverse mode.
The second power switch (S2) is turned on, connecting the output voltage source to the primary side of the flyback transformer.
Energy is transferred from the output source to the transformer's primary winding during the switch-on period.
The primary current ramps up, transferring energy to the transformer's core.
When the second switch (S2) turns off, the energy stored in the transformer's core causes the voltage to spike.
The active clamp circuit, which now operates in reverse, absorbs the energy, limiting the voltage spike and protecting the switches.
By efficiently controlling the voltage spikes during both power delivery and power regeneration modes, the bidirectional active-clamped flyback converter ensures smooth and safe bidirectional power flow between the two sources. This converter is commonly used in applications where bidirectional energy transfer is required, such as electric vehicles, energy storage systems, and renewable energy integration.
The main principle of a bidirectional AC flyback converter involves the use of two power switches (usually MOSFETs) and an active clamp circuit to control the voltage and current flow during both power delivery and power regeneration phases. Here's a step-by-step explanation of the operating principle:
Power Delivery Mode:
When power needs to be delivered from the input source (e.g., a battery or a DC power supply) to the output source (e.g., a load or another battery), the converter operates in the forward mode.
The first power switch (S1) is turned on, connecting the input voltage source to the primary side of the flyback transformer.
Energy is stored in the transformer's primary winding during the switch-on period.
The primary current ramps up, storing energy in the transformer's core.
When the first switch (S1) turns off, the energy stored in the transformer's core causes the voltage to spike.
The active clamp circuit, which consists of a second power switch (S2) and a clamp capacitor, comes into play here.
The second switch (S2) is turned on, creating a closed loop for the energy stored in the transformer's leakage inductance to circulate through the clamp capacitor.
The active clamp circuit absorbs the energy, limiting the voltage spike and protecting the switches from excessive voltage stresses.
Power Regeneration Mode:
When power needs to be regenerated or transferred back from the output source to the input source (e.g., during regenerative braking in an electric vehicle or energy recovery in a renewable energy system), the converter operates in the reverse mode.
The second power switch (S2) is turned on, connecting the output voltage source to the primary side of the flyback transformer.
Energy is transferred from the output source to the transformer's primary winding during the switch-on period.
The primary current ramps up, transferring energy to the transformer's core.
When the second switch (S2) turns off, the energy stored in the transformer's core causes the voltage to spike.
The active clamp circuit, which now operates in reverse, absorbs the energy, limiting the voltage spike and protecting the switches.
By efficiently controlling the voltage spikes during both power delivery and power regeneration modes, the bidirectional active-clamped flyback converter ensures smooth and safe bidirectional power flow between the two sources. This converter is commonly used in applications where bidirectional energy transfer is required, such as electric vehicles, energy storage systems, and renewable energy integration.