Slope Compensation Design for a Peak Current-Mode Controlled Boost-Flyback Converter

Peak current-mode control is widely used in power converters and involves the use of an external compensation ramp to suppress undesired behaviors and to enhance the stability range of the Period-1 orbit. A boost converter uses an analytical expression to find a compensation ramp; however, other more complex converters do not use such an expression, and the corresponding compensation ramp must be computed using complex mechanisms. A boost-flyback converter is a power converter with coupled inductors. In addition to its high efficiency and high voltage gains, this converter reduces voltage stress acting on semiconductor devices and thus offers many benefits as a converter. This paper presents an analytical expression for computing the value of a compensation ramp for a peak current-mode controlled boost-flyback converter using its simplified model. Formula results are compared to analytical results based on a monodromy matrix with numerical results using bifurcations diagrams and with experimental results using a lab prototype of 100 W.

Download Full-text

Slope Compensation Design for a Peak Current-Mode Controlled Boost-Flyback Converter

10.20944/preprints201809.0554.v1 ◽

2018 ◽

Author(s):

Juan-Guillermo Muñoz ◽

Guillermo Gallo ◽

Fabiola Angulo ◽

Gustavo Osorio

Keyword(s):

High Voltage ◽

High Efficiency ◽

Power Converters ◽

Mathematical Expression ◽

Current Mode ◽

Input Voltage ◽

Switching Frequency ◽

Peak Current ◽

Flyback Converter ◽

Coupled Inductors

Power converters with coupled inductors are very promising due to the high efficiency and high voltage gain. Apart from the aforementioned advantages, the boost-flyback converter reduces the voltage stress on the semiconductors. However, to obtain good performance with high voltage gains, the controller must include two control loops (current and voltage), and a compensation ramp. One of the most used control techniques for power converters is the peak current-mode control with compensation ramp. However, in the case of a boost-flyback converter there is no mathematical expression in the literature, to compute the slope of the compensation ramp. In this paper, a formula to compute the slope of the compensation ramp is proposed in such a way that a stable period-1 orbit is obtained. This formula is based on the values of the circuit parameters, such as inductances, capacitances, input voltage, switching frequency and includes some assumptions related to internal resistances, output voltages, and some other electrical properties related with the physical construction of the circuit. The formula is verified numerically using the saltation matrix and experimentally using a test circuit.

Download Full-text

Performance Analysis of a Peak-Current Mode Control with Compensation Ramp for a Boost-Flyback Power Converter

Journal of Control Science and Engineering ◽

10.1155/2016/7354791 ◽

2016 ◽

Vol 2016 ◽

pp. 1-14 ◽

Cited By ~ 6

Author(s):

Juan-Guillermo Muñoz ◽

Guillermo Gallo ◽

Gustavo Osorio ◽

Fabiola Angulo

Keyword(s):

Closed Loop ◽

Power Converters ◽

Monodromy Matrix ◽

Current Mode ◽

Power Converter ◽

Dynamical Analysis ◽

Dynamical Equations ◽

Peak Current ◽

Operation Conditions ◽

The Stability

High voltage gain power converters are very important in photovoltaic applications mainly due to the low output voltage of photovoltaic arrays. This kind of power converters includes three or more semiconductor devices and four or more energy storage elements, making the dynamical analysis of the controlled system more difficult. In this paper, the boost-flyback power converter is controlled by peak-current mode with compensation ramp. The closed-loop analysis is performed to guarantee operation conditions such that a period-1 orbit is attained. The converter is considered as a piecewise linear system, and the closed-loop stability is determined by using the monodromy matrix, obtained by the composition of the saltation matrixes with the solutions of the dynamical equations in the linear intervals. The largest eigenvalue of the monodromy matrix gives the stability of the period-1 orbit, and a deep analysis using bifurcation diagrams let us reach a conclusion about the loss of the stability, which is experimentally verified. To avoid overcompensation effects, the minimum value required by the compensation ramp is obtained, and the minimum and maximum values of the load resistance are found too. The system has a good transient response under disturbances in the load and in the input voltage.

Download Full-text

Stability Analysis in Positive Output and Negative Output DC to DC Converters Used in Renewable Energy Applications

10.20944/preprints201911.0288.v1 ◽

2019 ◽

Author(s):

Maheswari Ellappan ◽

Kavitha Anbukumar

Keyword(s):

Renewable Energy ◽

Stability Analysis ◽

Output Voltage ◽

Monodromy Matrix ◽

Period Doubling ◽

Current Mode ◽

Power Converter ◽

Control Technique ◽

Step Down ◽

The Stability

The renewable energy source plays a major role in the grid side power production. The stability analysis is very essential in the renewable energy converters. In this paper the bifurcation is analyzed in ZETA converter and Continuous input and output(CIO) power Buck Boost converter. The ZETA converter gives positive step down and step up output voltage and the CIO power converter gives the negative step up and step down output voltage. These converters are used in the DC micro grid with renewable energy as the source. The current mode control technique is applied to analyze the bifurcation behavior and the reference current is taken as the bifurcation parameter. When the reference current is varied, both the converters loses its stability and it enters into chaotic region through period doubling bifurcation. The simulation results are presented to study the performance behavior of both the converters. The stability region of both the converters are determined by deriving the Monodromy matrix approach.

Download Full-text