The difference between resonant commutation and self commutation isa)b...
Resonant commutation and self commutation are two different methods used in power electronic circuits for the commutation of power devices such as thyristors or transistors. Let's understand the difference between these two methods:
1. Resonant Commutation:
- Resonant commutation is based on the principle of using resonant elements such as inductors (L) and capacitors (C) to achieve the rapid turn-off of power devices.
- In resonant commutation, the commutating elements (inductors and capacitors) are designed in such a way that they resonate at a specific frequency.
- When the power device needs to be turned off, a resonant voltage is applied across the device, causing the current to decrease rapidly.
- Resonant commutation is commonly used in high-frequency power electronic circuits, where the switching speed is crucial.
2. Self Commutation:
- Self commutation, also known as natural commutation or line commutation, is a method where the power device is turned off by the natural behavior of the circuit without using any external commutating elements.
- In self commutation, the commutation process relies on the circuit's inductance and capacitance, rather than external components.
- When the current through the power device reaches zero naturally, the voltage across the device changes polarity, allowing it to turn off.
- Self commutation is commonly used in AC-to-DC converters or DC-to-AC inverters, where the power device needs to be turned off at a specific point in the AC cycle.
Explanation of the Correct Answer:
The correct answer is option 'A' - both these methods are based on entirely different principles.
- Resonant commutation and self commutation are indeed based on entirely different principles of operation.
- Resonant commutation relies on the use of resonant elements (L and C) to achieve rapid turn-off, while self commutation relies on the natural behavior of the circuit for turn-off.
- Therefore, there is a fundamental difference in the principles of operation between these two methods.
In summary, resonant commutation and self commutation are two distinct methods used for the commutation of power devices. Resonant commutation uses resonant elements (L and C) to achieve rapid turn-off, while self commutation relies on the natural behavior of the circuit. Therefore, option 'A' is the correct answer as it accurately describes the difference between these two methods.
The difference between resonant commutation and self commutation isa)b...
Resonant commutation and self commutation are two different methods used in power electronics for the commutation of power semiconductor devices like thyristors and transistors. Let's understand the difference between these two methods:
1. Resonant commutation:
- Resonant commutation is based on the principle of creating a resonant circuit using inductance (L) and capacitance (C) elements.
- In this method, the commutation process is initiated by applying a voltage across the commutating elements (L and C) of the circuit.
- The commutating elements carry load current during the commutation process.
- The resonance created by the L and C elements helps in transferring the load current from the turned-off device to the newly turned-on device.
- Resonant commutation is commonly used in high-power applications where the switching frequency is low and high energy transfer is required.
2. Self commutation:
- Self commutation, also known as line commutation or natural commutation, is based on the principle of the natural voltage or current reversal in the circuit.
- In this method, the commutation process occurs automatically without any external control or additional circuit elements.
- The commutating elements do not carry load current during the commutation process.
- Self commutation is achieved by utilizing the natural conditions of the circuit, such as the reversal of voltage or current.
- Self commutation is commonly used in low-power applications where the switching frequency is high and less energy transfer is required.
Explanation of the correct answer (option A):
The correct answer is option A, which states that resonant commutation and self commutation are based on entirely different principles. This is true because resonant commutation relies on the creation of a resonant circuit using L and C elements, whereas self commutation relies on the natural conditions of the circuit for commutation. Resonant commutation requires external control and the commutating elements carry load current, while self commutation occurs automatically without external control and the commutating elements do not carry load current. Therefore, the two methods are fundamentally different in their principles of operation.