Performance Analysis of a High Gain Bidirectional DC-DC Converter Fed Drive for an Electric Vehicle With Battery Charging Capability During Braking

This research presents a novel non-isolated high gain bidirectional DC-DC converter (BDC) and its application in integrating energy storage system with electric vehicle (EV). The proposed converter can provide high voltage gain with the help of two duty cycle operation by employing fewer components in its circuit design. The proposed topology makes use of dual current path inductor structures which reduces their size and eliminates the need for an additional clamping circuit to power the load. Without using voltage multiplier cells (VMC) or hybrid switched-capacitor approaches, the proposed converter can achieve a significant voltage gain. The simulation of the proposed converter-based drive is carried out using MATLAB/Simulink and OPAL-RT software in loop (SIL) system and the performance analysis is done for different driving conditions. The converter powers the motor through the battery during the forward motoring mode. The motor acts as a generator during regenerative braking and the energy is transferred back through the converter to the battery which stores the recovered energy.


I. INTRODUCTION
Governmental bodies and organizations are enforcing stricter limits for fuel consumption and emissions due to the rising rate of oil consumption in the transportation sector, as well as growing concerns over the impact of global warming and the depletion of energy resources.By 2040, it is predicted that the yearly sales of EVs and Hybrid Electric Vehicles (HEVs) would surpass those of petrol and diesel vehicles, with sales of over 48 million [1].The automobile industry is concentrating on the development of new technologies for the power train, battery, and charging infrastructure in response to the rising demand for vehicles with better fuel efficiency and less impact on the environment.The installation of a high-energy The associate editor coordinating the review of this manuscript and approving it for publication was Liu Hongchen .battery pack and regenerative braking aid in extending the driving range and battery life of electric vehicles.
Power electronic converters find its application in drivetrain to modulate the power flow from battery to the propulsion motors and to facilitate regenerative braking in the reverse direction.To increase efficiency and power density, the drivetrain motor and propulsion inverter are made to operate at higher voltage [2].To raise the battery voltage to the desired level, a boost converter is used.It also enhances the overall performance of the drivetrain by delinking the battery voltage and the inverter dc link voltage [3].The DC-DC converter must be bidirectional because the forward mode will face transient and overload conditions during which power gets transferred from the battery to load and during the reverse mode, the battery pack is to be charged.Some of the benefits derived by providing a BDC between the battery and the inverter [4], [5] are: a) It reduces the stress on the inverter with an additional DC stage b) It adjusts the inverter supply voltage to increase the motor output, c) The cost and size of the battery can be reduced because of lower cell count requirement and d) The system voltage and battery can be individually designed by the manufacturers.This architecture thus enables versatile system designs for vehicles with various output characteristics.For instance, the battery nominal voltage in the 2010 Toyota Prius is about 200 V, while the DC-DC converter raises the voltage of the dc bus to about 650 V [2].
The most common BDC is the one with an isolated framework [2], [6], [7], [8], [9], [10], [11].These isolated converters employ the high frequency transformer throughout the operation, increasing its losses and volume.Transformer core saturation [25] is another issue with this kind of converter.Additionally, many isolated converter configurations, such as LLC converters, CLLC converters and dual-activebridge (DAB) converters, which are the most prevalent kind of isolated BDCs, call for a significant number of active switches [10], [11].Therefore, non-isolated BDCs are typically preferred when isolation is not mandatory.This is due its simple structure and low component count, which draw the attention of several researchers.They are suitable for some applications, such as the drive train of an electric vehicle, where size and weight are crucial considerations.
To attain high conversion ratios, non-isolated BDCs employ many circuit principles, including SEPIC/Cuk/Zeta, voltage multiplier cells, switching capacitors, and linked inductors.Due to their cascaded construction, SEPIC/Cuk/ Zeta converters have a low efficiency and higher voltage stress.BDCs can be designed using voltage multiplier cells; however, this is restricted by the high voltage across switches.BDCs [12], [13], [14] utilize switched capacitors that perform better, have a simpler construction, and require less control complexity.However, for high-gain applications, the circuit becomes progressively complex and is susceptible to losses with the growing number of switches and capacitors.
The system efficiency can be increased with hybrid topologies, but there is insufficient voltage gain and a greater ripple current [15] associated with few of these topologies.However, high conversion factors can be attained using hybrid architectures like SEPIC/quasi-Z source with switched capacitors [16], [17].Conversion efficiency is nonetheless limited by a high component count and its inability to provide soft switching.Large ripple current at the LV side is a prevalent issue with all high gain non-isolated BDC circuits as it shortens the life and degrade the performance of the battery.Large capacitors can control input ripple current [18], but it is not the preferred option due to the added bulk and cost to the system.Interleaved DC-DC converter is a better option to reduce the input current ripple, but it has a lower voltage gain and more components [19].
Another significant advancement in this regard is the coupled inductor-based bidirectional converter (CIBDC) architecture [20], [21], [22], [23], [24], [25] that aims to achieve a high voltage conversion ratio.Contrary to transformer-based topologies, these coupled inductor-based systems [20] allow energy exchange at several instants during the course of a single time period.By carefully planning the circuit, switch current and voltage stress can be reduced as well.Clamping the coupled inductor's leakage energy and minimizing voltage spikes and stress across switches are major challenges in coupled inductor topologies.By raising the coupled inductance at the low voltage side, the CIBDC proposed in [21] could minimize the current ripple.But it restricts the number of turns of other windings and in turn the voltage transfer ratio of the BDC.The CIBDC suggested in [24] employs two secondary coupled inductor branches to obtain a greater voltage conversion ratio and current sharing features in addition to soft switching.A non-isolated high gain converter for microgrids is suggested in [26], where coupled inductor is substituted by a normal inductor to make the topology appropriate for high voltage conversion application.However, it is unidirectional.The proposed converter is a modified version of the converter in [26] with bidirectional capability for electric vehicle applications.
The proposed high gain bidirectional converter (HGBDC) utilizes only four active power switches which makes its construction simple.High voltage gain is achieved by choosing the appropriate duty cycle and designing proper inductor and capacitor values.Operation of the converter at a lower duty ratio reduces the core saturation problem of the inductor.Furthermore, the input current is divided among the inductors, which reduces their size and eliminates the need for an additional clamping circuit to give energy to the load.The performance analysis of the converter fed drive has also been carried out using MATLAB/Simulink and OPAL-RT SIL system to prove the viability of the converter in interfacing energy storage device to the dc link in electric vehicles.The converter successfully controls the power flow from the energy source to the motor and vice versa during forward motoring and regenerative braking.
In Section II, the topology and operation of the proposed HGBDC is covered, and in Section III, the specification and design of the converter fed drive system are discussed.The modelling and simulation of the converter fed drive in MAT-LAB/Simulink is given in Section IV.Section V describes the implementation of the proposed converter in RT-LAB real time simulation system.The summary of the work is presented in Section VI.

II. PROPOSED HIGH GAIN BIDIRECTIONAL DC-DC CONVERTER (HGBDC)
The proposed HGBDC shown in figure 1 has four active power switches (S 1 , S 2 , S 3 , and S 4 ), two identical inductors (L 1 and L 2 ), a diode (D 1 ), and a capacitor (C H ) at the high voltage side.Diode D 1 helps in blocking the reverse voltage V L appearing across the MOSFET while the switches S 1 and S 2 are conducting in boost mode.A switching frequency of f s is used by the switches S 1 , S 2 , S 3 , and S 4 .During boost mode, switches S 1 and S 2 have a duty ratio of d 1 , and switch

1) MODE I
The switches S 1 and S 2 are turned on in this mode (t 0 , t 1 ), while the switches S 3 and S 4 are turned off for the duration of d 1 T s .Energy flow is from the battery to the inductors L 1 , L 2 which are connected in parallel, as shown in figure 2(a).The energy stored in the capacitor; C H is released to the load.The voltage across the inductors is expressed in (1) to (3).
where v L1 and v L2 are the voltages across inductors L 1 and L 2 respectively.

2) MODE II
Switch S 3 is active for the duration of d 2 T s , while switches S 1 and S 2 are turned off in Mode II (t 1 , t 2 ).As displayed in figure 2(b), current flow is through L 1 , D 1 , S 3 and L 2. The energy from the source is delivered to the inductors.The load receives the energy that is stored in the capacitor.Source is in series with the inductors in this mode.Equations ( 4) and ( 5) represent the currents flowing through and the voltages across the inductors.where i L1 and i L2 are the current through inductors L 1 and L 2 respectively. whereas, 3) MODE III The MOSFET switches S 1 , S 2 and S 3 are turned off in this mode (t 2 , t 3 ), whereas the body diode of the MOSFET S 4 conducts during (1-d 1 -d 2 )T S .Diode D 1 is reverse biased.The load is supplied by both the source and the inductors as depicted in figure 2(c).The capacitor C H is in charging mode as the body diode of S 4 is forward biased.The inductors are connected in series to the source.The current through and the voltage across the inductors are given in ( 8) to (10).
From ( 9) and (10), (3), (7), and (11) are combined to get (12) using the state space averaging technique: The modes of operation are indicated by the superscripts I, II, and III.The resulting voltage gain is given by (13).

B. OPERATION OF THE PROPOSED HGBDC IN BUCK MODE
The buck operation of the converter is explained in two different phases during the same switching cycle.The current flow path of the proposed HGBDC operating in buck mode is depicted in figure 4. Energy is transferred from the high voltage side to the low voltage side with the help of controlled switches S 4 , S 1 and S 2 in this mode.The switch S 4 is operated through the PWM control with a duty ratio of d b.Operational waveforms of the proposed HGBDC in buck mode for continuous conduction mode (CCM) are depicted in figure 5.

1) MODE I
In this mode (t 0 , t 1 ), S 4 is turned on and S 1 /S 2 /S 3 are turned off for a duration of d b T s .The inductors L 1 and L 2, which are connected in series with the load and the battery, facilitate the transfer of energy from the high voltage side to the low voltage side of the converter as shown in figure 4(a).Equations ( 14) to (16) give the current flowing through and the voltage across the inductors in this mode.
14502 VOLUME 12, 2024 Authorized licensed use limited to the terms of the applicable license agreement with IEEE.Restrictions apply.whereas, 2) MODE II The body diodes of the MOSFETs S 1 and S 2 conduct for a duration of (1−d b )T s in this mode (t 1 , t 2 ), while the MOSFET S 4 is turned off. Figure 4(b) depicts the current flow path.Inductors L 1 and L 2 discharge their stored energy to the load on low voltage side.Because L 1 and L 2 are in parallel, the voltages across them are as given in (17).
Equations ( 16) and ( 19) are combined to get (20) using the state space averaging technique.
The modes of operation are indicated by the superscripts I and II.The resulting voltage gain in buck mode is given by (21).
where, d b is the duty ratio of the HGBDC in buck mode of operation.

C. EFFICIENCY ANALYSIS
In order to determine the theoretical efficiency curve and compute converter losses, the efficiency of the proposed converter is derived by taking the parasitic elements into consideration.To make the mathematical analysis simpler, the ripple in the capacitor voltage and inductor current is ignored.By taking these parasitic elements into consideration, the expression for voltage V H at the high voltage side of the converter, is given by (22). where, where, r L1 and r L2 are the ESR of the inductors L 1 and L 2 respectively.Similarly, r S1 , r S2 , r S3 and r S4 represent the ONstate resistances of the switches S 1 , S 2 , S 3 and S 4 respectively.r D1 and V D1 are the internal resistance and the voltage drop across the diode D 1 respectively.The resulting equation for efficiency of the proposed converter in boost mode of operation is given in (23).
where, P H and P L are the power at high voltage side and low voltage side of the converter respectively.R H is the load resistance at high voltage side.P SW is the switching loss across the power switches which is given by (24).The rise and fall time of the power switches are represented by t r and t f respectively.
The expression for voltage V L at the low voltage side of the converter, by taking the parasitic elements into consideration is given in (25). where, The calculated efficiency of the proposed converter in stepdown mode is given by (26).
where, R L is the load resistance at low voltage side.

D. COMPARISONS WITH OTHER CONVERTERS
A comparison of the proposed converter with similar non isolated bidirectional converters is listed in Table 1.The comparison is made in terms of voltage gain, number of inductors, capacitors and switches, frequency of operation, power level, intended application and efficiency.The proposed HGBDC uses only four power switches and one diode, which is minimal when compared to the converters in [12], [16], [17], [19], and [25].The number of inductors and capacitors are also least in comparison with the other converters.In Figure 6, the voltage gain against duty cycle is plotted for each of these converters.The voltage gain of the proposed HGBDC is higher than in other converters between a duty cycle range of 0.45 to 0.6 as can be seen in figure 6.The proposed HGBDC uses two different duty ratios 'd 1 ' and 'd 2 ' to achieve high voltage gain.With a constant duty ratio 'd 2 ' as 0.35, 'd 1 ' is varied for plotting the graph.The converters in [24] and [25] use coupled inductors for which the turns ratio 'n' is taken as unity for plotting the graph.When duty ratio d 1 is at 0.6, the proposed HGBDC offers a high voltage gain of 32.However, the voltage gain of other converters are less than 15 for the same duty ratio.
14504 VOLUME 12, 2024 Authorized licensed use limited to the terms of the applicable license agreement with IEEE.Restrictions apply.The efficiency of the proposed converter calculated based on equations ( 23) and ( 26) for boost and buck mode respectively.Table 2 lists the parasitic parameters of components for the MOSFET (IXFH120N30X3) and diode (STTH6004W) as given in the datasheets.ESR of the inductor is estimated to be 24 m .The voltages at the high voltage side and low voltage side of the converter are 240V and 48V respectively.Theoretical efficiency curves in both boost and buck modes are plotted in figure 7. The calculated efficiency for a rated power of 3.73 kW is found to be 94.12% in boost mode and 95.51% in buck mode.The maximum efficiencies are 95.7% and 96.6% in boost and buck modes which are comparable to the efficiencies of the counterparts presented in Table 1 and better than that of the converter presented in [21].Frequency, power level and intended application of the converters are also compared in Table 1.Even though the applications of the compared converters are meant for interfacing storage devices to the dc link, the performance analysis for the complete system is not discussed in the reference papers.

III. CONVERTER DESIGN AND MOTOR CONTROL
The proposed HGBDC may be used to test its viability for applications like electric automobiles by integrating it into a simple DC motor drive.In this work, the converter is operated in continuous conduction mode to drive the dc motor in forward motoring and regenerative braking modes.The HGBDC is connected to a battery and a dc motor load as shown figure 8.The light electric vehicle industry makes extensive use of DC motors, which are chosen for their simplicity and to check the viability of the converter operation in the proposed scheme.A 5 HP separately excited DC motor model rated at 240 V and 1750 rpm is utilized as the load to analyze the performance of the HGBDC in both MATLAB/Simulink and the OP4500 real-time simulation mode.The converter specifications are given in Table 3.The simulation makes use of the lithium ion (Li-ion) battery, whose specifications are listed in Table 4.The lithium-ion battery has a strong possibility of replacing other batteries as the foreseeable future of electric vehicle batteries.This is due to its fascinating properties including large power density, high energy density, extended life cycle, absence of memory effect, and superior energy efficiency.During regenerative braking, the proposed BDC transfers power from the motor back to the battery, and when the vehicle is moving, it delivers power from the battery to the DC motor.

A. INDUCTOR DESIGN
The selection of an inductor is influenced by the motoring mode of operation, which in turn depends on the input voltage (V L ), current ripple ( iL ), frequency of switching (f s ), and the duty cycle (d 1 ).The critical inductance value for the operation of the proposed HGBDC in CCM is determined using (27).
The inductor has been designed with 50 kHz switching frequency and a specified current ripple which is considered as 12% of the input current.

B. CAPACITOR DESIGN
The rated power (P o ) of the converter, load voltage (V o ), ripple voltage ( V c ), and the frequency of switching (f s ), are used to calculate the value of the capacitor, C H on the high voltage side using (28).
A voltage ripple of 1% of the output voltage, V H is used for the design of the capacitor.

C. VOLTAGE STRESS OF THE SWITCH AND DIODE
The voltage stress V DS1 , V DS2 , V DS3 and V DS4 across switches S 1 and S 2 , S 3 and S 4 for boost mode of operation are given by ( 29), ( 30) and (31).
The voltage stress V D1 on the diode D 1 for both buck and boost mode of operations are given by equation (32).
The voltage stress V DS1 , V DS2 , V DS3 and V DS4 across switches S 1 and S 2 , S 3 and S 4 for buck operation are given in (33) and (34).

D. CONTROL TECHNIQUE
A practical technique for adjusting the speed of the drive is to control the output voltage of the BDC.A PID controller is used to ensure that the vehicle reaches the target speed and reacts quickly to rapid changes in speed without oscillations.Figure 9 depicts the control circuitry for the HGBDC.It senses the motor speed ω motor and compares it to the reference speed ω ref .
The error signal is processed by the PID controller and compared to a high-frequency sawtooth signal to generate the PWM control signals.

IV. MODELLING AND SIMULATION
The HGBDC fed DC motor drive is modelled and simulated using MATLAB/Simulink for a duration of 10 seconds.The steady-state inductor current and the gate drive pulses of the MOSFET switches for both boost and buck mode of operations of the converter are shown in figure 10 and figure 11 respectively.In boost (forward motoring) mode, the inductor current increases when the first three switches S 1 , S 2 and S 3 are turned on, whereas the current through the inductor decreases when the switch S 4 is turned on.As shown in figure the average value of the inductor current in steady state is 32 A. During buck (regenerative braking) mode, the steady-state inductor current is -13.5A.Negative value of the current shows the reversal of current flow from the load to source; hence the power flow.Battery is charged from the regenerative power during this braking mode.For a rated speed of 1750 rpm in forward motoring mode, the duty ratio of the PWM pulses generated by the PWM controller, d 1 and d 2 for the switches S 1 /S 2 and S 3 respectively are 0.455 and  Two different cases are considered for analyzing the dynamics of the system: (i) transition of the motor operation from forward motoring to regenerative braking.
(ii) a step change in speed during forward motoring.

A. TRANSITION OF THE MOTOR OPERATION FROM FORWARD MOTORING TO REGENERATIVE BRAKING
The converter is made to operate in boost (forward motoring) mode from 0-5 seconds and in buck (regenerative braking) mode from 5-10 seconds.Figure 12  Authorized licensed use limited to the terms of the applicable license agreement with IEEE.Restrictions apply.shown in figure 12(g) and 12(h) respectively.Around 5000J of energy is recovered during regenerative braking.

B. A STEP CHANGE IN SPEED DURING FORWARD MOTORING
A step change in motor speed from 1250 RPM to 1750 RPM at constant torque constitutes the second instance of transient operation.The battery and motor energy characteristics are shown in figure 13(h).
The theoretical efficiency of the of the proposed HGBDC is calculated for rated power and resistive load and is found to be 94.12% in boost mode and 95.51% in buck mode as discussed in section II-D.The results are in good agreement with the simulation results which are 94.57% and 95.05% respectively.

V. IMPLEMENTATION OF THE PROPOSED CONVERTER IN REAL-TIME SIMULATION SYSTEM
Software-in-the-loop (SIL) analysis is performed prior to real time Rapid Control Prototyping (RCP) or Hardware-inthe-Loop (HIL) testing of any system.The key advantage of SIL is that it does not require external input or output, ensuring signal consistency.Synchronization with the outside environment is hardly essential since the controller and the plant are functioning in the same simulator.In this section, both the controller and the plant are tested using a real-time simulator (OP4500) built on the RT-Lab platform.
The Simulink models of the battery, converter, motor, and associated control circuit are integrated with RT-Lab blocks and are accessible on the host computer which is linked to the OP4500 simulation target through a Transmission Control Protocol (TCP)/Internet Protocol (IP) communication network, as shown in figure 14.The OP4500 simulation target performs real-time computations for model inputs and outputs.To analyze the dynamics of the system, a step change in torque is applied and the forward motoring and regenerative braking modes are realized.Also, the impact of variation in speed during forward motoring mode is analyzed.The converter operating frequency is limited to 5 kHz to make it compatible with the existing RT-LAB platform.
Waveforms of the HGBDC operating in forward motoring (boost) mode are shown in figure 15.Gate pulses V gs1 , V gs2 , V gs3 and V gs4 are given in figure 15(  displays the waveforms for the inductor currents I L1 and I L2 , the armature current I a , and the armature torque T a .This demonstrates that the converter is operating in buck mode and that energy is successfully transferred from the DC motor to the battery.
The switching of the HGBDC fed drive from motoring mode to the regenerative braking mode is depicted in figure 17.The operation of the regenerative braking mode is indicated by negative torque and currents.It is observed that the results obtained using OPAL-RT software in loop test plat form is in good agreement with the simulation results obtained using MATLAB/Simulink.

VI. CONCLUSION
This paper focused on the design and development of a High Gain Bidirectional Converter (HGBDC) for electric vehicle applications with battery charging capability during regenerative braking.The performance analysis of the converter is carried out during motoring and regenerative braking modes in both MATLAB/Simulink and real time simulation environment with RT-LAB.The proposed method is simpler and the converter can attain high gain with the help of two duty cycle operation.It demonstrates a good balance among the voltage gain and the component counts which gives a viable solution to the application of interfacing storage devices to the DC link in electric vehicles which is the focus of the paper.The HGBDC also successfully controls the power flow direction by modifying the converter's working mode from motoring to regenerative braking.The efficiency of the proposed converter can further be improved by selecting SiC based power switches.Further Soft switching can be implemented to reduce the switching losses when the converter operates at higher frequency, but it adds complexity and increases the number of components.

S 3
has a duty ratio of d 2 .The duty ratio of the switch S 4 is (1-d 1 -d 2 ) during boost mode and it is d b during buck mode of operation of the converter.A. OPERATION OF THE HGBDC IN BOOST MODE The boost operation of the converter is explained in three different phases namely, Mode I, Mode II and Mode III.The current flow path of the proposed HGBDC operating in boost mode is depicted in figure 2. During this mode, the energy is transferred from the low voltage side to the high voltage side of the converter with the help of controlled switches S 1 , S 2 , S 3 and S 4 .The switches S 1 , S 2 and S 3 are operated through the PWM control.Typical waveforms of the proposed HGBDC in boost mode for continuous conduction are shown in figure 3.

FIGURE 2 .
FIGURE 2. HGBDC in boost mode (a) Mode I (b) Mode II (c) Mode III.

FIGURE 7 .
FIGURE 7. Efficiency versus output power of the proposed HGBDC.

FIGURE 9 .
FIGURE 9. Block diagram of closed loop control scheme.

FIGURE 10 .
FIGURE 10.Switching signals for S 1 , S 2 , S 3 , S 4 and inductor currents in boost mode of operation.

FIGURE 11 .
FIGURE 11.Switching signals for S 1 , S 2 , S 3 , S 4 and inductor currents in boost mode of operation.

FIGURE 12 .
FIGURE 12. Simulation results for case1-transition of the motor from forward motoring to regenerative braking: (a) speed, (b) armature current, (c) armature torque, (d) armature (output) voltage of the motor, (e) battery voltage and (f) battery SoC (g) battery current (h) battery and motor energy.
action with a speed change from 1750 rpm to 1150 rpm when the motor current and torque exhibit a reversal characteristic as shown in figure12(a), 12(b) and 12(c) respectively.The change in directions of current and torque during the transition from motoring mode to regenerative braking mode indicates the reversal of power flow.As seen in figure 12(d) armature voltage decreases in proportion to the decrease in speed.There is a dip in battery voltage and reduction in SOC of the battery during forward motoring (0 to 5 seconds).But the battery voltage and SoC of the battery increases during regenerative braking as observed in figure 12(e) and 12(f).The SoC of the battery increases by 0.02% from 79.95 to 79.97 during a short span of 5s in regenerative braking mode.The battery current and the energies of battery and motor are

Figure 13 (
a) depicts the speed waveform for a duration of 10 seconds.It is observed that the system settles down at the new speed within 0.5 seconds.The momentary change in armature torque caused by a sudden alteration in the speed is seen in Figure13(c).The characteristics of current that is identical to that of torque is shown in figure13(b).The change in armature voltage with respect to the change in motor speed is depicted in figure13(d).As seen in figure13(e), when the speed increases, the motor draws more energy from the source, resulting in a fall in the SoC of

FIGURE 14 .
FIGURE 14. Real-time software in loop test platform.

FIGURE 17 .
FIGURE 17. Switching of the motor from motoring mode to regenerative braking mode: inductor currents I L1 & I L2 (CH1), armature current I a (CH2) and armature torque T a (CH3).
a), whereas the steady-state inductor currents are displayed in figure 15(b), together with switching PWMs.The inductor currents I L1 and I L2 , armature current I a , and armature torque T a are positive during motoring (boost) mode and are shown in figure 15(c).Waveforms of the output voltage, input voltage and steady state speed are shown in figure 15(d).The waveforms for the buck mode of operation of the proposed HGBDC are shown in figure 16.The steady-state inductor currents I L1 , I L2 , and switching PWMs are shown in Figure 16(a).

TABLE 1 .
Comparison of the proposed converter with other converters.
FIGURE 6. Voltage gain versus duty cycle of the converters.

TABLE 2 .
Parasitic parameters of components.
FIGURE 8. HGBDC connected to battery source and a dc motor load.
shows the motor speed, armature torque, armature current, armature voltage (output voltage V H ) of the converter, battery SoC and battery voltage for this case.Simulations are carried out for the braking