Project 1 - Loss calculation for a DC/DC converter-MATLAB
- Extending the learned lessons in previous module, you will be diving into another power electronics concept on your own.
- Design of boost converter, and calculating the loss of different components including power switching device and deriving efficiency of boost converter. This is applicable in power supply industry, electric vehicles etc where DC-DC converter is required to boost the voltage from DC source. All the aspects of this project with loss calculation, device selection, simulation etc are industry relevant.
AIM :
To design and derive the power electronics concept of boost converter and calculation of the losses of different components including power switching derive and DC-DC converters.
THEROY OF DC-DC converter :
The DC-DC Converter block represents a behavioral model of a power converter. This power converter regulates voltage on the load side. To balance input power, output power, and losses, the required amount of power is drawn from the supply side. Alternatively, the converter can support regenerative power flow from load to supply.
Voltage Droop
Voltage droop is the loss in output voltage for a device that drives a load. Droop is important in voltage regulation circuits as it increases the tolerance of the systems towards load transients.
A separate value for the droop allows you to control how the output voltage varies with the load regardless of load-dependent losses. To enable droop, select the Enable droop parameter. To specify the droop, set the Droop parameterization parameter to:
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By voltage droop with output current— Set the voltage droop directly by specifying the value of the Output voltage droop with output current parameter. -
By percent voltage droop at rated load— This equation calculates the voltage droop as a percent of the Output voltage reference demand parameter, based on the value of the Voltage droop percent at rated load parameter:
ΔV=Dpercent100Vref_droop
D=ΔV(Vref_droop−ΔV)Prated
Synchronous vs. Asynchronous Boost Converters
The two primary types of DC-DC converters used in electronics are buck converters and boost converters. A buck converter steps down the output voltage, and a boost converter steps up the output voltage. There is also the buck-boost converter, where the step-up or step-down function is controlled by adjusting the duty cycle of a PWM signal, which is used to switch a transistor in the converter circuitry.
Among boost converters, there are two different types: synchronous and asynchronous boost converters. The L-filter across the output is intended to remove any residual ripple or high frequency noise at the output from the boost converter (it is a low-pass filter). These converters use power MOSFETs driven with a PWM signal to hold charge and a stable voltage across the output capacitor. The images below show the topology of synchronous and asynchronous boost converters.
MATLAB SIMULINK MODEL OF DC-DC CONVERTER :
Given value :
- Vin = 100 V;
- Vout = 200 V;
- L = 200uH ;
- C = 400uF;
- R= 10 Ohms;
- rL = 10 mOhms;
- rC = 2 mOhms;
Circuit Diagram of DC-DC converter :
This means that the output voltage flies back to the switching node and the voltage across the inductance V(L1) becomes the output voltage minus the voltage drop of the diode: V(L1)M = VO – VF. Vice versa, the maximum voltage V(L1)M is defined as the maximum output voltage minus the voltage drop of the diode.
Calculation of losses :
CONCLUSION :
To completed all the claculation of boost converter, and calculating the loss of different components including power switching device and deriving efficiency of boost converter. This is applicable in power supply industry, electric vehicles etc where DC-DC converter is required to boost the voltage from DC source. All the aspects of this project with loss calculation, device selection, simulation etc are industry relevant.