Two-Switch Boost Converter With Improved Voltage Gain and Degree of Freedom of Control

The use of renewable resources for low power generation has led to extensive research on power converters for reliable and efficient power conversion. Though conventional boost converter (CBC) remains the widely used topology, its operating range is limited due to constraints on voltage gain and degree of freedom of control (DoFoC). This paper presents a two-switch boost converter (TSBC) which improves the voltage gain and DoFoC by cascading an additional switch-diode pair to the CBC circuit. The additional switch enhances the range of voltage gain without operating CBC at high duty ratios. Additionally, TSBC offers more choices to adjust voltage gain, which enhances DoFoC. The switching interval selection is detailed considering the voltage gain and constraints on circuit variables. The design formulations of TSBC are examined to facilitate optimal choice of components. The features of TSBC are theoretically established with mathematical derivations and are validated by simulations and experiments. The experimental results indicate that for a duty ratio of 0.7 for the existing switch of CBC, an increase in voltage gain from 3.2 to 4.3 is achieved when the duty ratio of the additional switch in TSBC is varied from 0 to 0.1. Similarly, improved DoFoC is demonstrated with inductor current control as well as with constant ripple ratios while maintaining the required output voltage. The proposed converter can easily replace the commonly CBC to improve the gain and DoFoC by simply cascading a switch-diode pair at the input-side of CBC.


I. INTRODUCTION
Renewable resources and energy storage systems such as solar photo-voltaic (PV), wind turbines, fuel cells, and battery storage have steadily gained acceptance as dependable and low-cost means of fulfilling the ever-increasing energy demand. As a result, the number of non-conventional sources integrated into the existing distribution system has extensively increased over the past few decades. This escalating use of renewable resources along with the advancement in the area of semiconductor devices and the competitive energy market has influenced the research on power converter The associate editor coordinating the review of this manuscript and approving it for publication was Chi-Seng Lam .
interfaces (PCIs) [1], [2]. PCIs are primarily ought to have a simple structure with small size and high efficiency [3]. To achieve safe, stable, cost-effective, and reliable integration, developing converters that comply with updated standards and achieve increased efficiency is critical.
Several existing low-power renewable resources have high power to voltage ratio and therefore require a voltage boosting stage [4], [5]. The conventional boost converter (CBC) is most commonly used for this purpose due to its simple circuit and available comprehensive analysis [2]. However, CBC exhibits several inadequacies in many applications, one of which is the constraint on its practical voltage gain. Although CBC theoretically yields significant voltage gains, it is practically unattainable due to parasitic resistances, stresses on VOLUME 11, 2023 This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ switching devices, as well as stability and efficiency concerns at high duty ratios. This limit on voltage gain can lead to over-sizing of the sources [6], [7]. To this end, several step-up converters have been proposed in the existing literature. The topologies for step-up DC-DC converters can be categorized as isolated and non-isolated converters [8]. Isolated converters use traditional or multi-winding transformers to achieve the necessary voltage gain and maintain isolation between input and output sides [9], [10], [11], [12]. The existence of a transformer, on the other hand, necessitates a high-frequency stage and increases the total loss. Due to low cost, size, and efficiency, non-isolated converters are frequently preferred in low-power systems [6]. Many existing non-isolated converters achieve high voltage gain ratios by increasing the voltage multiplier cells [4], [5], using coupled inductors with high turns ratios or with switched capacitor [13], [14] or inductor modules [15], [16], [17]. Though transformer-based or coupled-inductor-based highgain converters have several advantages, the presence of magnetic elements with strict design constraints degrades its structural simplicity [10], [18]. The switched capacitor and inductor converters, on the other hand, necessitate a large number of high-frequency switching devices and suffer from excessive current and voltage spikes during transients [13]. Another method to attain high voltage gain is with cascaded converters [19], [20]. If integrated with careful design of components, the cascading technique can be used to develop converters with improved voltage gains.
Another restriction of CBC is the lack of diverse degrees of freedom of control (DoFoC) under continuous conduction mode (CCM). This implies the duty ratio is varied to control only one variable. Due to this, the CBC is designed at the rated maximum operating conditions which results in over-sizing of the converter. This initiated the development of converters with higher DoFoC. High gain converters based on coupled-inductor impedance sources depend on the inductor turns ratio and coupling to increase DoFoC [21], [22], [23], [24]. In [25], a boost converter with interleaved inductor and switched capacitor voltage multiplier to eliminate input current ripple at a pre-selected duty ratio is presented. However, pre-selection of duty ratio may not be feasible in many applications. A soft-switching boost converter with unidirectional cell to increase DoFoC and efficiency is proposed in [18]. However, its voltage gain require further analysis and comparison. Several high-gain converters in literature achieve higher DoFoC with complex circuit or control strategies. Contrarily, cascaded converter configurations resolve the constraint on DoFoC and attain increased voltage gains.
Considering the above-mentioned factors as motivation, a two-switch boost converter (TSBC) is proposed in this paper to improve the voltage gain of CBC by cascading a switchdiode pair. The inclusion of extra switch increases the DoFoC in comparison to CBC. The proposed TSBC circuit is easy to implement by including a switch-diode pair to CBC in case of an existing PCI or by using two half-bridges in a new system. The significant contributions of the paper are as follows.
• A novel TSBC with improved voltage gain with minimal circuit changes to CBC • Analysis to apprehend the increased DoFoC due to the inclusion of the additional switch • A meticulous switching interval selection to provide ease of control implementation • A detailed formulation for component sizing of the proposed TSBC to facilitate simple hardware development The rest of the paper is organized as follows. Section II discusses the proposed TSBC circuit and analyzes it during different states of operation to derive Important formulations including the voltage gain and current relations. The increased DoFoC due to the availability of multiple switching combinations is explained in section III. In section IV, the improvement in voltage gain of the proposed TSBC in comparison to CBC is presented. The selection of duty ratios considering constraints on different variables is discussed in section V. Section VI contains formulations for optimal component sizing, followed by a comparison of specifications for the proposed TSBC and CBC. The simulation and experimental findings are reported in section VII to validate the theoretical claims of improved voltage gain and DoFoC. The conclusions from the theoretical analysis and results are finally summarized in section VIII.

II. CIRCUIT ANALYSIS OF PROPOSED CONVERTER
The circuit of the proposed TSBC is shown in Fig. 1 with an input voltage V in and output voltage V o across a load R o . It consists of an input filter capacitor C in , a pair of switches (S 1 , S 2 ), a pair of diodes (D 1 , D 2 ), an inductor L, and output capacitor C o . The average input, output and inductor currents are denoted by I in , I o and I L respectively. The switches can be operated synchronously or independently. The circuit implementation of TSBC is considered to be simple as it comprises of a switch and diode at the input side of CBC.

A. CIRCUIT ANALYSIS
Assuming CCM operation, diodes D 1 and D 2 conduct in complement to switches S 1 and S 2 respectively. Hence, there exist four states of operation based on switching conditions of S 1 and S 2 as shown in Table 1 and are discussed as follows.

1) STATE 0
The circuit operates in state 0 for the time interval t 0 when both the switches are OFF. If the inductor current i L is nonzero, the diodes D 1 and D 2 conduct as shown in Fig. 2. The input source along with the inductor supply power to the load. The voltage and currents of energy storage elements are determined by circuit analysis as shown in (1).
2) STATE 1 During state 1, the switch S 1 is ON while S 2 is OFF as shown in Fig. 2b. The time interval for this state is t 1 . The input source supplies the input capacitor C in while the output capacitor C o supplies the load. The inductor current i L remains constant and circulates through S 1 and D 2 . The following equations are obtained by circuit analysis of Fig. 2b.

State 2
The circuit operates in state 2 for t 2 , during which the switch S 1 OFF while switch S 2 is ON. The inductor is charged from the input via the diode D 1 and switch S 2 , while the load is supplied solely by the output capacitor C o . The following equations are obtained for this state. [

State 3
Both switches S 1 and S 2 are ON for a interval of t 3 in state 3. The inductor L discharges to the output capacitor C o and the load, while the capacitor C in is sourced from the input.
The equations that characterize this state are as follows. [ From the circuit analysis, the operation of TSBC in state 0 and state 2 are noted to be identical to that of CBC. Hence, the proposed TSBC operates as a CBC when switch S 1 remains off throughout the circuit operation.

B. VOLTAGE AND CURRENT RATIOS
If the passive components are assumed to be loss-less, the average energy dissipated across C in , L and C o during one (3) and (4), the following relation can be derived considering zero energy dissipation in the inductor.
Therefore, the relation between the output and input voltages can be derived in terms of the switching intervals as Similarly, by equating the average energy dissipated in the capacitors C in and C o to zero, we obtain (7) and (8).
From (7) and (8), the relation between average currents in the circuit is derived an in (9).
It is observed from (6) and (9), there exist multiple combinations of time intervals t 0−3 that yield the same voltage or current relation. This enables control of additional variables.

III. DUTY RATIOS AND OVERLAP OF SWITCH PULSES
Based on (6), different combinations of time intervals t 0−3 can be used to achieve a required voltage ratio. For ease of control implementation, these time intervals are hereafter expressed in terms of the duty ratios of switching pulses and the ratio of their overlap. Let the duty ratios of the switching pulses to S 1 and S 2 be d 1 and d 2 respectively while their ratio of overlap time to time period T be d OL as shown in Fig. 3. The duty ratios d 1 and d 2 and their overlap ratio can be expressed in terms of the intervals t 0−3 as in (10).
It is observed from (10) that for the same set of duty ratios (d 1 , d 2 ), the time intervals t 0−3 vary when overlap ratio d OL is varied. From Fig. 3, d OL can be varied by introducing a phase shift between the switching pulses S 1 and S 2 . The phase shift VOLUME 11, 2023  θ OL of S 2 w.r.t. S 1 in seconds for an overlap ratio d OL , can be obtained using (11) Multiple control parameters of TSBC, namely d 1 , d 2 and d OL , provide higher DoFoC in comparison to CBC in which d 2 is the only controllable parameter. The presence of the additional S 1 -D 1 pair also help improve the voltage gain.

IV. IMPROVEMENT IN VOLTAGE GAIN
To demonstrate the improvement in voltage gain, the proposed TSBC is compared with CBC. In (6), the voltage relation of TSBC is presented as a function of the switching intervals. However, a relation in terms of duty ratios provides a more perceptive representation for the purpose of comparison. Substituting time intervals from (10) in the voltage relation of (6), the voltage gain of TSBC is obtained as The CBC has only one switch and operates in two states which correspond to states 0 and 2 of TSBC. Hence, if S 1 is turned off throughout the operation of the converter, the proposed TSBC performs identical to CBC. The time intervals in CBC is obtained as t 1 = t 3 = 0 and t 0 + t 2 = T , and duty ratio d 1 = 0. The voltage gain of CBC is as in (13).
The voltage gain ratios of CBC and TSBC, G v C and G v , for varying duty ratios are presented in Fig. 4. The duty ratio d 2 is varied continuously while d 1 takes values from 0 to 0.8.
Considering the constraint of d 1 + d 2 < 1 from (12), the operating and non-operating ranges of TSBC are indicated in Fig. 4. When d 1 =0, the voltage gain of the TSBC is identical to that of the CBC. On the other hand, if d 1 > 0, the TSBC is capable of operating at higher voltage gains. For instance, at d 2 =0.7, the voltage gain of CBC (d 1 =0) is 3.33. If d 1 is varied to 0.1 and 0.2 while d 2 remains at 0.8, the voltage gain of TSBC is increased to 4.5 (35% increase) and 8 (140% increase) respectively. This improved voltage gain effectively implies that the operating range of TSBC is improved.
From (12), the voltage gain ratio G v is noticed to be independent of the overlap ratio d OL . As a result, the phase shift on the switching pulse S 2 w.r.t. S 1 has no effect on the voltage gain. The same voltage gain can be obtained with multiple choices of duty ratios, thereby increasing the DoFoC which is further explained in the following section.

V. INCREASE IN DoFoC AND CHOICE OF DUTY RATIOS
In CBC, the magnitude and ripples of the currents and voltages vary with the gain ratio and cannot be controlled as it has only one control variable d 1 i.e. one DoFoC. However, the proposed TSBC has more than one combination of d 1 , d 2 and d OL that yield the same voltage gain, which implies multiple DoFoC. Duty ratios can be chosen in accordance with multiple constraints in addition to voltage gain such as magnitude and ripple of currents and voltages, switching frequency, and/or switching losses. In this paper, the output ripple voltage V o and inductor current ripple I L are considered for the choice of duty ratios. Similar analysis can be performed for other parameters, such as inductor current magnitude, based on the application. The voltage gain G v and switching frequency f sw = 1 T are predefined. Additionally, for the simplicity of analysis and implementation, complete overlap case is assumed here. Therefore, the overlap ratio between the two switching pulse is fixed based on the following conditions. A

. CASE 1: INDUCTOR CURRENT MAGNITUDE
The inductor is often a sizable component in converters. Therefore, limiting the inductor current to an optimal value is considered appropriate to reduce the weight, size and cost of converter. Further, a control on the inductor current is useful to control input/output currents based on the application. If the inductor current is limited by the equation I L = xI o , the following relation is obtained from (9).
From (15), it can be observed that the inductor current ratio is independent of the overlap ratio d OL . Solving (15) using (19), we obtain the values of d 1 and d 2 as shown in (16).
Since the duty ratios are expected to be non-negative, the above equation results in the constraint x ≥ G v . Based on the duty ratios obtained from (16), switching pulses can be generated to attain the desired voltage gain G v and inductor current ratio x, and thereby control both output voltage V o and inductor current I L .

B. CASE 2: OUTPUT VOLTAGE RIPPLE RATIO
Many applications involve loads that require the output voltage V o to be stable with minimal ripple V o . Using circuit analysis, the ripple voltage can be expressed as in (17).
Let the output voltage ripple ratio be y = V o V o . Considering this limit on ripple voltage, we obtain the following relation.
From voltage gain of (12), the duty ratio d 1 is expressed as Substituting d OL and d 1 from (14) and (19) in (18), the following relation is obtained for output voltage ripple ratio.
The duty ratio d 2 is obtained by solving (20) and d 1 is obtained by substituting this value of d 2 to (19). The values of duty ratios and overlap ratio thus obtained will result in the specified gain G v and ripple ratio y of the output voltage.

C. CASE 3: INDUCTOR CURRENT RIPPLE RATIO
The inductor current ripple is one of the factors that define the inductor value for CCM operation. Hence, operating the converter at a predefined inductor current ripple can ensure CCM operation. The ripple current I L is correlated to the inductor L as per (21), where t is the interval during which I L changes by I L and v L is the voltage across it during t.
Substituting I L and v L during the switching state t 0 from Table 1 and using the voltage gain in (12), the inductor current ripple I L can be expressed as (22).
From the current relations in (9), the inductor current can be defined in terms of duty ratios by (23).
If the ripple current ratio is fixed to x, i.e. I L = x × I L , Substituting d OL and d 1 from (14) and (19), Solving (25), (19) and (14) in order yields the values of d 2 , d 1 and d OL respectively that results in the specified inductor current ripple ratio x while retaining the voltage gain at G v .

VI. OPTIMAL SELECTION OF COMPONENTS
The size and cost of a converter are determined by the ratings of its constituent components. The design of components used in TSBC is detailed as follows. The sizing of switches, diodes, inductor, and capacitors are based on rated values of parameters such as input voltage V in , switching frequency f sw , rated output voltage V oR , and rated power S R = V oR I oR .
These parameters are assumed to be fixed prior to design.

A. INDUCTOR
The rating of the inductor is decided based on the maximum of average and ripple currents through it. The ripple current decides the inductor value while the average current determines the current rating of the inductor. The maximum ripple current I L max is required to be limited to x=(10 to 30)% of the rated inductor current I LR . Since the inductor current and output current can be related by (9), the maximum ripple current at rated condition is expressed in terms of V oR as (26).
During all operating conditions, the inductor current is expected to satisfy the condition I L < I L−max . Therefore, from (22) and (26), the limit for inductance L is obtained as Considering d OL from (14), (d 2 (1 − d 1 − d 2 + d OL )) max =0.25. Therefore, the minimum value of inductor is In addition to the inductor value, the component specification of inductor includes the average current through it at rated operating conditions of the converter. The rated inductor current I LR can be derived from (9) as The sum of duty ratios d 1 + d 2 is limited to 0.9 to enable efficient operation of the converter. Therefore, the maximum inductor current can be expressed as in The minimum inductor value from (28) and its current rating from (30) are used for the choice of a suitable inductor. VOLUME 11, 2023

B. CAPACITORS
The capacitors in a converter are chosen based on the ripple and maximum values of voltages. The ripple voltage V C across a capacitor C can be related to its capacitance by (31).
Hence, from Table 1, the ripples of input and output voltages of the proposed TSBC are obtained as (32) and (33).
The maximum ripple V C is often limited as y = (5 to 10)% of the rated capacitor voltage V C . If y in and y are the limits of ripples in V in and V o respectively, i.e. V in−max = y in V in and V o−max = yV o the constraint on capacitor ratings can be calculated using (34) and (35).
Assuming the range of duty ratios is limited by d 1 + d 2 ≤ 0.9 to avoid low efficiency operation, the values of (d 1 G v ) max and (d 1 are obtained as 2.5 and 4.95 respectively. Substituting these in (34) and (35), the minimum value of capacitors are obtained as The maximum voltages across the capacitors C in and C o are V in and V oR respectively. These voltage ratings and the corresponding capacitor values from (34) and (35) are used for the selection of capacitors.

C. SWITCHES AND DIODES
The specification of switches and diodes are decided based on the maximum voltage, current and switching frequency. Assuming loss-less components, the voltages and currents through the switching components are determined by circuit analysis for four states of operation and listed in Table 2.  The current ratings of the switching devices in TSBC can be calculated as (38).

D. COMPARISON OF SPECIFICATIONS WITH CBC
In an existing CBC based system, the voltage gain and DoFoC can be improved by implementing TSBC by cascading the CBC with an extra switch-diode pair. For this to be practically feasible, the component specifications of the proposed TSBC should be comparable to CBC. Hence, a comparison of the component ratings in both converters is presented in Table 3 and discussed further to validate the viability of incorporating TSBC into the conversion system with an existing CBC. The ratings of components in CBC are considered to be a function of d 2 while those of TSBC depend on d 1 , d 2 and d OL . To avoid low efficiency operation of CBC, d 2 is often limited, to say 0.9. Similarly, in TSBC, the sum of duty ratios d 1 +d 2 is limited to 0.9 while d OL is set to min(d 1 , d 2 ). Considering these limits, the specifications of the components in Table 3 for CBC and TSBC are found to be identical. The additional components in TSBC, S 1 and D 1 , have the same current ratings and reduced voltage ratings as the  other switching components. The comparable ratings of all constituent components support TSBC implementation by cascading a switch-diode pair with an existing CBC.

VII. RESULTS AND DISCUSSION
The theoretical analysis of the proposed TSBC is verified using simulations on MATLAB/Simulink platform and hardware prototype shown in Fig. 5. A constant input voltage of 30 V and resistive load 170 W are considered. The ratings of the converter are specified in Table 4. The performance of the TSBC is assessed using an open-loop control implemented using dSPACE MicroLab Box with duty ratios values considering d 1 + d 2 < 0.85 and d OL = min(d 1 ,d 2 ). The results of TSBC with d 1 = 0 are regarded similar to those of CBC. From (12), (13) and (16), the output voltage and inductor current in CBC and TSBC can be expressed in terms of duty ratios as shown in Table 5. Here, the input voltage V in and output resistance R o are considered known variables. Based on the equations for CBC in Table 5, if an output voltage of V o = 60 V is to be obtained from an input voltage V in = 30 V , only one value of duty ratio, i.e. d 2 = 0.5, can be used. The inductor current in CBC is as function of this duty ratio and thus cannot be independently controlled. Similarly, if I L is controlled using d 2 , V o cannot be controlled to any required value as it is dependent on and only on d 2 . Note that here the input voltage V in and output resistance R o are not used for control. On the contrary to CBC, there exists multiple combinations of [d 1 , d 2 ] for TSBC, that can be used to obtain an output voltage of V o = 60 V from V in = 30 V . This is because when only V o is controlled, it results in only one VOLUME 11, 2023 Fig 6a and the specific values are mentioned in Table 6 for the purpose of comparison.
It is noticed from Fig. 6, for CBC, one variable, i.e. either V o or I L can be controlled using d 2 . On the other hand, from Fig. 6b for TSBC, it is observed that both V o and I L can be controlled simultaneously using d 1 and d 2 . This validates the increased DoFoC due to the switch-diode pair in TSBC.

B. CONTROL OF RIPPLE RATIOS USING DoFoC
The increased DoFoC is further validated by operating the TSBC at different voltage gain ratios while retaining constant ripple ratios as shown in Fig. 7a. The duty ratios are chosen based on (20) and (25) for constant output voltage ripple ratio and inductor current ripple ratio respectively. For simplicity of switching pulse generation, the overlap ratio between the two switching pulse is fixed as min(d 1 , d 2 ).
In Fig. 7a, the results for constant output voltage ripple ratio of y = 0.06 are presented. The duty ratios calculated based on (20) (20).     Fig. 8c. This validates the improvement of voltage gain using the control of d 1 .
The voltage gain G v , output voltage ripple ratio y, inductor current ripple ratio x obtained by theoretical calculation (Calc.), simulation (Sim.) and experiment (Exp.) are summarized in Table 7 for the ease of comparison. For all the duty ratios considered, the calculated voltage gain and ripple VOLUME 11, 2023  ratios are observed to be comparable with those obtained in simulation and experiment. This validates the theoretical analysis presented in the paper. For a constant value of d 2 , say 0.3, the calculated voltage gain G v increases from 1.43 to 1.67 and 2.5 with d 1 = 0, 0.25 and 0.5 respectively. Both simulation and experimental results for voltage gain are consistent with these theoretical values. The inductor ripple current ratio is observed to reduce as d 1 increases. Therefore, TSBC can restrain the inductor current ripple ratio at higher voltage gains due to the additional switch-diode pair. Although the output ripple voltage rises with d 1 , it can be limited by utilizing the additional DoFoC feature of the proposed converter which is detailed further in the subsequent discussion of results. If y in and y are the limits of ripples in V in and V o respectively, i.e. V in−max = y in V in and V o−max = yV o the constraint on capacitor ratings can be calculated using (34) and (35).
The above results indicate that the addition of a switch-diode leg at the CBC can aid to improve the voltage gain ratio as well as the DoFoC. Hence, the proposed TSBC can be used to control other circuit parameters, such as inductor current or voltage/current ripple ratios in addition to the evident control on voltage gain.

D. ANALYSIS OF EXPERIMENTAL EFFICIENCY
The experimental voltage gain and efficiency of the proposed TSBC for different duty ratio values are presented in Fig. 9a for the rated operating condition. In Fig. 9, the theoretically calculated gain is validated using the experimentally obtained voltage gain values. The duty ratios d 1   experimental values of voltage gain varies from the calculated ideal values. This is owing to losses incurred in the switches at high duty ratios and output voltages as can be observed from the efficiency plots in Fig. 9b. Fig. 9(i) and (ii) illustrate the relation of experimental efficiency η with d 2 and G v respectively. The maximum efficiency is observed as 96.2% and competent efficiency is observed for the range d 1 + d 2 < 0.7. The experimental efficiency reduces with increase in d 2 and G v .
The proposed TSBC can be considered as a derived topology of the CBC by cascading a switch-diode pair to bring about an improvement in voltage gain and DoFoC. There exist several derived or cascaded topologies that achieve improved variations its substituent converters. Among these, the relevant converter topologies are compared with TSBC to highlight its many advantages. Table 8 compares the experimental efficiency of the proposed TSBC is compared with other cascaded converter configurations alongside other parameters such as voltage gain and component count. Since the experimental efficiency are obtained at different system ratings for different converters in the existing literature, the voltage, power and frequency rating at which the converter topology was tested is also listed in Table 8. In comparison, the proposed TSBC has the least number of passive components as well as the least overall component count. This contributes to reduced size and initial cost of the converter. Additionally, the efficiency of TSBC is on par with that of existing converters, including those that use soft switching. The proposed converter is also observed to be the most comparable topology to CBC and hence can easily replace CBC in existing systems without inclusion of additional passive components or complex changes in circuit and control. Hence, the range of application for the proposed TSBC can be considered as all power conversion systems that conventionally employ CBC, for example, within the power conversion interface of a PV-based stand-alone or grid connected system.

VIII. CONCLUSION
In this paper, a two-switch boost converter is proposed to enhance the voltage gain and increase the DoFoC in power conversion interfaces. The circuit of TSBC is analysed for its four states of operation based on which the voltage and current ratios are derived. The combination of switching pulses for different duty ratios and overlap ratio is detailed and the improvement in voltage gain ratio is presented with a comparison to CBC. The formulations related to the choice of duty ratios based on the ripple ratios of output voltage and inductor current are derived to demonstrate the improved DoFoC of TSBC. The design of constituent components in TSBC are discussed. The simulation and experimental results validate the theoretical claims of TSBC presented in this paper. The experimental results indicate that for a duty ratio of 0.7 for the existing switch of CBC, an increase in voltage gain from 3.2 to 4.3 is achieved when the duty ratio of the additional switch in TSBC is varied from 0 to 0.1. Similarly, improved DoFoC is demonstrated with inductor current control as well as with constant ripple ratios while maintaining the required output voltage. The proposed converter can easily replace the commonly CBC to improve the gain and DoFoC by introducing only two additional components at the input side of the circuit.