Indonesian J our nal of Electrical Engineering and Computer Science V ol. 39, No. 3, September 2025, pp. 1499 1513 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v39.i3.pp1499-1513 1499 An impr o v ed h ybrid A C to DC con v erter suitable f or electric v ehicles applications Khaled A. Mahafzah 1 , Mohamad A. Obeidat 2 , Hesham Alsalem 3 , A yman Mansour 4 , Eleonora Ri v a Sanse v erino 5 1 Department of Electrical Engineering, F aculty of Engineering, Al-Ahliyya Amman Uni v ersity , Amman, Jordan 2 Department of Electrical and Mechatronics Engineering, F aculty of Engineering, T ala T echnical Uni v ersity , T ala, Jordan 3 Department of Mechanical Engineering, F aculty of Engineering, T ala T echnical Uni v ersity , T ala, Jordan 4 Department of Computer and Communications Engineering, F aculty of Engineering, T ala T echnical Uni v ersity , T ala, Jordan 5 Department of Engineering, Uni v ersity of P alermo, P alermo, Italy Article Inf o Article history: Recei v ed Oct 24, 2024 Re vised Apr 17, 2025 Accepted Jul 3, 2025 K eyw ords: EV char ging Flyback HVDC grid Hybrid con v erter SEPIC ABSTRA CT This paper introduces a no v el h ybrid A C-DC con v erter designed for v arious ap- plications lik e DC micro-grids, electric v ehicle (EV) setups, and the inte gration of rene w able ener gy resources into electric grids. The suggested h ybrid con- v erter in v olv es a diode bridge rectier , tw o interconnected single ended primary inductor con v erter (SEPIC) and Flyback con v erters, and tw o additional auxiliary controlled switches. These e xtra switches f acilitate switching between SEPIC, Flyback, or a combination of both. The paper e x-tensi v ely discusses the oper - ational modes using mathematical equations, deri ving specic dut y c ycles for each switch based on the circuit par ameters. This h ybrid con v erter aims t o de- crease total harmonic distortion (THD) in the line current. The ndings e xhibit a THD of approximately 14 . 51 %, sho wcasing a 3 % reduction compared to prior h ybrid con v erters, thereby enhancing the po wer f actor of the line current. Fur - thermore, at rated load conditions, the proposed con v erter achie v es 90 % ef - cienc y . T o v alidate the proposed h ybrid con v erter’ s functionality , a 4 . 5 kW con- v erter is simulated and performed using MA TL AB/Simulink after conguring the appropriate passi v e parameters. This is an open access article under the CC BY -SA license . Corresponding A uthor: Khaled A. Mahafzah Department of Electrical Engineering, F aculty of Engineering, Al-Ahliyya Amman Uni v ersity Amman 19328, Jordan Email: k.mahafzah@ammanu.edu.jo 1. INTR ODUCTION Global w arming, fuel emissions, fuel prices, and politics ha v e mo v ed customers’ attention to more dependable and en vironmentally benecial rene w able and friendly ener gy sources. W ith o v er 95 million cars sold each year , the transportation sector contrib utes more than 24 % of global emissions [1]. California, Eng- land, France, German y , and man y European countries will ban selling con v entional internal comb ustion engine v ehicles starting from 2035 and after . Recent technology impro v ements in po wer electronics and the utilization of these adv ancement in transportation plays a major role for the wide spread of electric v ehicles (EV) later on [1], [2]. Demands of EVs increased rapidly and manuf acturers started to enhance their ef ciencies and competencies. Depending on the source of electricity used to char ge EV , emissions from EV can decreased to up to 90 % compared to emi s- sions from ICE. EV mainly consist of dif ferent components such as the rechar geable battery , po wer in v erters, J ournal homepage: http://ijeecs.iaescor e .com Evaluation Warning : The document was created with Spire.PDF for Python.
1500 ISSN: 2502-4752 electric traction motor , po wer electronics controller , char ging port, and transmission. The rechar geable battery (v oltages v ary from 200 V to 450 V) that passes DC v oltage to the in v erter . Po wer in v erters changes the current from DC current to an A C current [3]. Electric t raction motor turns the transmission and the traction wheels, and the po wer electronics controller w orks as a con v erter/in v erter combination. The char ging port allo ws the EV to be connecting to an e xternal source to char ge the traction battery pack whene v er needed. There are four major types of EVs; battery electric v ehicle or all electric v ehicle (BEV or EV), h ybrid electric v ehicle (HEV), plug in h ybrid electric v ehicle (PHEV), fuel cell electric v ehicle (FCEV) [1]-[3]. EV is a noise free v ehicle, with the most ef cient components that o v ercome all ICEs [4]-[6]. EVs can be di vided into three main subsystems cate gories [1], [7], [8]. First, the high v oltage circuit which includes the rechar geable battery between 200 to 800 v olts, contractors which relay po wer to motor which propel the v ehicle controlled by in v erters, DC to DC con v erter , on board char ging unit, smart shunt used for battery managements and can b us which control po wer deli v ery and implement performance and safety features. Second, lo w-v oltage circuit, which is responsible for operating the accessory de vice through rear PDU-8 which programmed to acti v ate the in v erters cooling pump, tai llight blink ers and re v erse light. Front PDU-8 controls the CAN k e ypad, digital dash display accurately . T w o additional PDU-8 used to acti v a te the contractors for the high v oltage systems and control the headlights. Third, multiple can netw orks. Which allo ws multiple de vices to share data between the netw orks and guarantee an optimal and safe performance. In v erters can be the k e y solution in the eld of h ybrids and electrical v ehicles. The motor in h ybrid and EVs utilize three phase v oltage source in v erters (VSI) based on insulated g ate bipolar transistors IGBTs made of silicon carbides or g allium nitrides to turn on and of f within fe w mile or nano-seconds [9], [10]. The e xploration of a three-phase modular dif ferential in v erter (MDI) inte grating single ended prim ary inductor con- v erter (SEPIC) modules and SiC de vices is discussed, deli v eri ng A C po wer to the grid with enhanced ef cienc y and reduced total harmonic distortion (THD) through high-frequenc y switching and modular e xibility [11]. T akaoka et al. [12] introduces of an isolated DC to single-phase A C con v erter that incorporates acti v e po wer decoupling using a coupled inductor and interlea v ed boost con v erter , achie ving i ndependent control of po wer con v ersion, an 84 . 5 % reduction in second-order harmonics, and a maximum ef cienc y of 94 . 5 %. Larouci et al. [13] e xamines a yback con v erter using a mix ed conduction mode, balancing ef cienc y and transformer v olume by combining discont inuous and continuous conduction modes within an optimized control frame- w ork, f a v oring continuous conduction for ef cienc y and discontinuous conduction to minimize component v olume. Collecti v ely , these studies adv ance po wer con v ersion technologies by enhancing grid-connected sys- tem ef cienc y , reducing harmonic distortions, and optimizing design approaches for impro v ed performance and scalability . Another type of in v erters is the current source in v erters (CSI) with the aid of a capacitor lters to re gu- late the distortion currents. Z source in v erter (ZSI) is an in v erter that combine both VSI and CSI. The produced v oltage from ZSI is either higher or lo wer than the input v oltage source. Three le v el in v erters used in EV with switches that are more ef cient especially for m o de rate to high frequenc y le v els with lo wer v oltage distortion and higher motor ef cienc y . Insulated g ate bipolar transistors (IGBTs) is a major part used in in v erters [14]- [18]. Po wer module as well as g ate dri v ers are responsible for the dynamic beha vior of the diodes. Current sensor and DC link capacitor are components used in in v erters as a means of protection and better performance control [19]. All in v erters are equipped with a thermal management system to control T empera-ture through cooling system (w ater -cooling or forced air -cooling). Che vrolet MY2016 V olt used traction po wer in v erter module (TPIM) with dual VSIs and wide bandg ap (WBG) [20]. T o yota MY2016 Prius used tw o VSIs, a boost con v erter . Nissan MY2012 LEAF used a single VSI. T esla model S uses 5 . 8 kg 6 . 4 L, T O-247 w ater -cooled in v erter . Dif ferent generations of in v erter were used by each indi vidual EV Automak er to o v ercome short- comings from pre vious models and ha v e an impro v ed performance. Some EV and HEV has dif ferent types of in v erters that perform as an in v erter/con v erter assembly that w orks as boost con v erter , boost con v erter module, and the coil that produce the v oltage higher than battery v oltage. EVs and PHEVs tend to ha v e higher po wer in v erters in the range of 100 500 kW compared to the 30 to 60 kW range in HEV [5], [21], [22]. In response to the demand for adv anced po wer electronics systems tailored specically for EVs, this paper introduces a cutting-edge h ybrid A C-DC con v erter , redening the landscape of ener gy con v ersion tech- nology . Recognizing the need for a more nuanced focus on con v erters within the EV domain, we ha v e tailored our introduction to pro vide a comprehensi v e o v ervie w of our inno v ati v e solution, minimizing redundant infor - mation commonly kno wn about EVs. The de v eloped h ybrid con v erter , designed with a primary dedication to EV applications, transcends con v entional boundaries by of fering a v ersatile solution for a range of scenarios. Indonesian J Elec Eng & Comp Sci, V ol. 39, No. 3, September 2025: 1499–1513 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 1501 Be yond EVs, its applications e xtend to DC micro-grids and the seamless inte gration of rene w able ener gy re- sources into electric grids. This adaptability is achie v ed through a sophist icated architecture, featuring a diode bridge rectier , coupled SEPIC, and yback con v erters. The inte gration of tw o auxiliary switches further ele- v ates the con v ert-er’ s e xibi lity , allo wing dynamic selection between SEPIC, yback, or a h ybrid mode to suit di v erse operational requirements. This paper e xplores specic duty c ycles for each switch, le v eraging mathe- matical calculations grounded in circuit parameters. This in-depth analysis ensures optimal performance across v aried operational modes, emphasizing the practical utility and adaptability of our con v erter to meet the unique demands of EV applications [23]-[25]. One study e xamines the direct po wer control (DPC) technique for three-phase PWM A C-DC con v er t- ers under un ba lanced v oltage conditions. It highlights ho w such conditions can lead to signicant performance de gradation due to the presence of ne g ati v e v oltage components in the grid, which adv ersely af fect the operation of grid-connected VSIs. By modifying the con v entional DPC input structures with simpler sequence netw orks, the study achie v ed a 70 % impro v ement in input po wer under unbalanced conditions, measured through a re- duction in THD [26]. Another research paper e xtends this w ork by emphasizing the necessity of addressing symmetrical components to mitig ate the adv erse ef fects of unbalanced v oltage, impro ving po wer quality and reducing THD [27]. A dif ferent approach in v olv es the analysis of virtual ux direct po wer control (VFDPC) for A C-DC con v erters. This technique eliminates the need for v oltage sensors by estimating grid virtual ux based on con v erter switching states, line current, and DC-link output v oltage. This method not only simplies the control system b ut also achie v es lo w harmonic distortion (belo w 5 %) and near unity po wer f actor , making it highly suitable for EV applications [28]. Additionally , another study proposes a tw o-stage bidirectional A C- DC con v erter utilizing w a v elet modulation for EV char ging systems. The results demonstrate a signicant reduction in output v oltage ripple and harmonic distortion, enhancing the o v erall performance of the char ging infrastructure [28]. The paramount objecti v e of the proposed h ybrid con v erter is to address the follo wing issues: Inte grated SEPIC and yback con v erters: the combination allo ws the con v erter to switch between SEPIC and yback modes or use both simultaneously . This e xibility optimizes performance under v arying load conditions, which is not typically seen in con v entional topologies. Auxiliary controlled switches: these additional switches pro vide a mechanism to dynamically select the op- timal mode of operation. This is a unique feature that dif ferentiates your design from more static approaches in traditional and inte grated con v erters. Reduced THD: the proposed con v erter achie v es a THD of 14 . 51 %, which is lo wer than man y e xisting h ybrid con v erters. This impro v ement in THD directly contrib utes to better po wer quality and more ef cient operation. Ef cienc y impro v ements: at rated load conditions, the proposed con v erter reaches 90 % ef cienc y . Discuss ho w the inte gration of SEPIC and yback con v erters, along with the auxiliary switches, contri b utes to this high ef cienc y . Fle xibility in application: by accommodating dif ferent operational modes (SEPIC, yback, or a combina- tion), the con v erter can be tailored to specic applications lik e DC micro-grids or EV installations, pro viding superior adaptability compared to single-mode con v erters. Impro v ed po wer f actor: highlight ho w the reduction in THD contrib utes to an impro v ed po wer f actor , making the proposed con v erter more suitable for sensiti v e applications where po wer quality is critical. The rest of the paper is or g anized as follo w . Section 1 introduces the paper . Section 2 discusses the proposed h ybrid con v erter . Section 3 discusses the simulation results. Section 4 discusses the ability of the proposed con v erter to impro v e the grid current po wer f actor . Finally , section 5 concludes the paper . 2. THE PR OPOSED HYBRID CONVER TER Figure 1 sho ws the impro v ed h ybrid A C-DC con v erter . It comprises of con v entional diode bridge rectier , tw o DC-DC con v erters (yback and SEPIC con v erters), one main switch M 1 , tw o additional switches A 1 and A 2 and lo w pass lter capacitor C o (This capacit or represents C f or C s ). The use of tw o DC-DC con v erters, without introducing tw o auxiliary switches, is proposed in [22]. In this paper , the impro v ed h ybrid A C-DC con v erter is dedicated to EVs applications. T o char ge the main and auxiliary storage system in EVs An impr o ved hybrid A C to DC con verter suitable for electric vehicles applications (Khaled A. Mahafzah) Evaluation Warning : The document was created with Spire.PDF for Python.
1502 ISSN: 2502-4752 from electrical grids, such conguration must be used. Ho we v er , due to non-linearity of output capacitance beha vior of the semiconductor switches at high switching frequenc y in the circuit, the po wer f actor of the line current will be smashed. Therefore, tw o auxiliary switches are inserted as seen in Figure 1 to reduce the THD in the line current (the input v oltage of Figure 1 is rectied v oltage by diode bridge rectier . The condition of A 1 and A 2 determines the combination of the tw o con v erters (yback or yback/SEPIC). The operation mode is dened by the condition of A 1 and A 2 . As a result, the switching frequenc y of the auxiliary switches is substantially lo wer than the switching frequenc y of t he main switch M 1 . Therefore, additional tw o auxiliary switches are switched at grid frequenc y ( 50 Hz or 60 Hz) to reduce the switching losses, because these losses increase dramatically with the switching frequenc y [29], [30]. Second, these switches are used to select the operated DC-DC con v erter . Conducted a comprehensi v e re vie w of three-port DC–DC con v erters’ topologies for inte grating rene w able ener gy and ener gy storage systems. Their w ork delv es into v arious con v erter con- gurations, shedding light on the e v olving landscape of sustainable ener gy inte gration. The authors analyze the strengths and limitations o f dif ferent topologies, contrib uting v aluable insights to the ongoing ef forts in adv ancing rene w able ener gy technologies. Figure 1. The proposed h ybrid A C-DC con v erter 2.1. Modes of operations The proposed h ybrid con v erter has a number of moods of operation depending on the status of s witches M 1 , A 1 , and A 2 . F or simplicity , all de vices are assumed to be ideal. The analysis is discussed in the follo wing detail. Mode 1 ( M 1 is on A 1 is of f and A 2 is of f): Figure 2 sho ws the rst tw o modes . During this mode, SEPIC and yback inductors are ener gized through the current path sho wn in Figure 2(a). When M 1 is on, then, V ds = 0 , (ideal switch), applying KVL o v er the left loop of Figure 2(a): V in + V Ls 1 + V L M = 0 , 0 < t < T on (1) then, V Ls 1 = V in V LM . Therefor , i Ls 1 = i LM and has a linear ramp. Then, the current is gi v en by: i Ls 1 max = V in L s 1 + L M D T s (2) and the v oltage of SEPIC inductor is equal to the v oltage across the coupling capacitor . It means that: V Ls 2 = V p (3) The current of L s 2 is gi v en by: i Ls 2 max = V cp L s 2 D T s (4) Mode 2 ( M 1 is of f A 1 is of f and A 2 is of f): this mode represents the resonance mode between the parasitic capacitance of the main switch and the other passi v e components in the circuit. See Figure 2(b). This mode is too short com-pared to switching time, so it can be ignored. Indonesian J Elec Eng & Comp Sci, V ol. 39, No. 3, September 2025: 1499–1513 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 1503 (a) (b) Figure 2. The equi v alent circuit the rst tw o modes (a) mode 1 and (b) mode 2 Mode 3 ( M 1 is of f A 1 is of f and A 2 is on): based on Figure 3, during this mode, the ener gy is transferred through the yback diode to output capacitor . Whereas the SEPIC output capacitance is dischar ged through the auxiliary switch A 2 , see Figure 3(a). The load v oltage is gi v en by (k eep in mind the transformer turns ratio is a : V o = V in a = V Ls 3 (5) Writing the current in secondary side of the transformer , this is gi v en by: i L s 3 = V Ls 3 L s 3 (1 D ) K 2 T s (6) Where K 2 =1- K 1 ,is the duty c ycle of A 2 , V C f = V o,f and i Ls 3 = ai Ls 1 . Mode 4 ( M 1 is of f A 1 is on and A 2 is of f): during this mode, the con v erter operates as boost con v erter . See Figure 3(b). The currents during this mode are gi v en by , respecti v ely: i Ls 1 min = ( V in V C p V o,s ) ( L s 1 + L M ) (1 D ) T s K 1 (7) i Ls 2 min = V o,s L s 2 (1 D ) T s K 1 (8) Where K 1 is the duty c ycle of switch A 1 , V Ls 2 = V o,s , and i Ls 1 = Same as mode 3. (a) (b) Figure 3. The equi v alent circuit the rst tw o modes (a) mode 3 and (b) mode 4 2.2. Duty cycles deri v ation T o dri v e the main switch duty c ycle M 1 , starting from the condition i Ls 1– mode 1 = i Ls 1– mode 3 , this gi v es: V in L s 1 + L M D T s = V in a 2 L s 3 (1 D ) T s (9) An impr o ved hybrid A C to DC con verter suitable for electric vehicles applications (Khaled A. Mahafzah) Evaluation Warning : The document was created with Spire.PDF for Python.
1504 ISSN: 2502-4752 Solv e for D , this yields: D = 1 a 2 L s 3 1 [ 1 L s 1 + L M + 1 a 2 L s 3 ] (10) to dri v e the switch A 1 duty c ycle, this condition must be satised. i Ls 1– mode 3 = i Ls 1– mode 4 (11) Then, V in a 2 L s 2 (1 D ) T s = V in V C p V o,s L s 2 + L M (1 D ) T s K 1 (12) V in a 2 L s 2 (1 K 1 ) = V in V C p V o,s L s 2 + L M K 1 (13) solv e for K 1 gi v es: K 1 = [ V in a 2 L s 2 ] 1 [ V in V C p V o,s L s 2 + L M + V in a 2 L s 2 ] (14) it should be noted that A 1 and A 2 are both complementary to each other . The ef fecti v e duty c ycle in po wer electronics con v erters can notably increase during high-frequenc y operations due to turn-of f and turn-on delay mismatches. This phenomenon arises from a misalignment be- tween the idealized switching e v ents and the actual t iming in practical applications. The consequence is an ele v ated ef fecti v e duty c ycle, which signicantly af fects the con v erter’ s performance, especially at higher switching frequencies. T urn-of f and turn-on delay mismatches become particularly pronounced with increased switching frequencies, posing challenges in accurately controlling the duty c ycle. This discrepanc y can result in v ariations in the e xpected output and ef cienc y of the con v erter , underscoring the necessity for a thorough understanding and mitig ation of these ef fects. The consideration of turn-of f and turn-on delay mismatches has been e xtensi v ely e xplored in the liter - ature, particularly in s tudies focusing on datasheet-dri v en modeling of po wer electronics con v erters. Mahafzah et al. [31], authors present a note w orth y contrib ution in the realm of po wer electronics with their duty c ycle re gulation based PWM control for a v e le v el ying-capacitor in v erter . This w ork addresses the intricacies of control mechanisms in multile v el in v erters, sho wcasing adv ancements in po wer electronics research and application. 2.3. P arameters design and selection The continuous conduction mode is selected to operate the proposed con v erter . It supplies a 4 . 5 kW load at 20 kHz switching frequenc y of switch M 1 and 50 Hz grid frequenc y of both auxiliary switches A 1 and A 2 . The selected the proposed con v erter components are computed as the follo wing steps: The magnetizati on inductance ( L m ) i s designed to reduce the ripple in the primary current. Therefore, reducing the design comple xity of the circuit’ s EMI lter [25]. The lo wer limit for this inductance is: L m min = (1 D ) 2 R o 2 f s (15) where f s is the switching frequenc y , and R o is the load resistance. The yback output capacitance C o plays an important role in reducing the output v oltage ripple, set the poles of the system transfer function, and imply the response of the supply to a sudden lar ge change of the load current [29]. The minimum limit of yback output capacitance is calculated by: C o,f min = D V o V o R o f s (16) where, V o V o is the required output v oltage ripple of the yback. Indonesian J Elec Eng & Comp Sci, V ol. 39, No. 3, September 2025: 1499–1513 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 1505 The transformer turns ratio ( a = N 1 N 2 ) is set to determine the proposed con v erter duty c ycle of the yback con v erter [29]. This reduces the yback diode v oltage stress and the v oltage stress on output capacitance. Then, the turns ratio can be calculated by: a = N 1 N 2 = V in D max V o,f (1 D max ) (17) The SEPIC inductance L s 2 are designed to mak e the EMI lter is simpler [30]. The inductance is gi v en by: L s 2 = V o (1 D ) I s 2 f s (18) where I s 2 is the desired current ripple in L s 2 . The SEPIC output capacitance C o,s is designed to be: C o,s min = I 2 8∆ V o,s f s (19) The SEPIC capacitance C p is desi gn e d to pass through a high RMS current when it is compared to C o,s , therefore, it should be selected to be (where L eq is the equi v alent of parallel inductance L M and L s 3 ): C p min = L eq I 2 2 2∆ V c p (20) The suggested con v erter is designed for medium po wer applications with a rated po wer of 4 . 5 kW to demon- strate its functionality . Thus, system characteristics such as input/output po wer , input/output v oltages, and switching frequenc y are specied; the other parameters are determined using the mathematical model pro- vided thus f ar . Switching frequenc y deri v ation: Ho we v er , to dri v e the switching frequenc y of the proposed con v erter the follo wing steps should be follo wed: based on (2) and (4), if M 1 is on, the drain current is gi v en by: I M = L s 1 + L s 2 (21) I M = V in ( L s 1 + L M ) T on V cp L s 2 T on (22) solving for T on gi v es: T on = I M V in ( L s 1 + L M ) V cp L s 2 (23) and based on (7), solving for T of f gi v es: T of f = I Ls 1 K 1 V in V cp V o,s L s 1 + L M (24) therefore, the con v erter switching time is T s = T on + T of f : T s = I M V in ( L s 1 + L M ) V cp L s 2 + I Ls 1 K 1 V in V cp V o,s L s 1 + L M (25) An impr o ved hybrid A C to DC con verter suitable for electric vehicles applications (Khaled A. Mahafzah) Evaluation Warning : The document was created with Spire.PDF for Python.
1506 ISSN: 2502-4752 2.4. V oltage contr ol loops The proposed con v erter needs tw o separate cont rol loops (Figure 4). The rst one to control the main switch, M 1 as seen in Figure 1. T o k eep the output v oltage within the acceptable limit ( V r ef ), a v ery simple v oltage control loop is used. The observ ed feedback v oltage is compared to a reference v oltage, as sho wn in Figure 4(a). The PI controller is used to lo wer the comparison stage’ s steady state inaccurac y . The d ut y c ycle of the main switch is the output of the PI controller stage. The g ate to source v oltage of the chosen MOSFET is then generated using the PWM generator at a gi v en switching frequenc y ( f s ). In summery , see Figures 4(a), 4(b), and results of control loop are seen in Figure 5. (a) (b) Figure 4. The output v oltage control (a) the rst control loop and (b) the second control loop Figure 5. Results of control loops (a) auxiliary switches selection condition and (b) pulses of all switches Finally , the auxiliary switches do not af fect the con v erter losses because the y ar e operating at 50 Hz (grid frequenc y), therefore, the associated losses are ne gligible. The determination of controller g ains within the PI controller plays a k e y role in achie ving stable and responsi v e control of the h ybrid A C-DC con v erter . W ithin the v oltage control loop go v erning the main switch ( M 1 ), the PI controller serv es to minimize steady state inaccuracies by comparing the observ ed feedback v oltage to the reference v oltage ( V r ef ). The proportional (P) component of the PI controller addresses immediate errors, while the inte gral (I) c o m ponent focuses on persistent of fsets, collecti v ely enhancing the controller’ s procienc y in maintaining the desir ed output v oltage. Selecting appropriate g ains for the PI controller in v olv es a precise tuning process, balancing the need for rapid responses to sudden system changes and the elimination of long term v oltage discrepancies. Thi s tuning is typically achie v ed through iterati v e processes, simulation studies, or empirical testing, ensuring optimal controller performance. The strate gic selection of PI controller g ains is equally crucial for the secondary control loop o v erseeing the auxiliary switches ( A 1 and A 2 ). Here, the PI controller contrib utes to maintaining equilibrium between the sinusoidal w a v eform and the DC v alue, f acilitating ef fecti v e g ating of the auxiliary switches. Analogous to the v oltage control loop, the proportional and inte gral g ains of the PI controller in this conte xt require precise tuning for swift responses to changes in the sinusoidal w a v eform and accurate control o v er the operation of the auxiliary switches. This detailed tuning process is instrumental in achie ving the desired performance characteristics of the proposed h ybrid A C-DC con v erter , ensuring a dynamic response to system changes and precise re gulation of both main and auxiliary switches. Indonesian J Elec Eng & Comp Sci, V ol. 39, No. 3, September 2025: 1499–1513 Evaluation Warning : The document was created with Spire.PDF for Python.
Indonesian J Elec Eng & Comp Sci ISSN: 2502-4752 1507 Mahafzah et al. [32], authors conduct a thorough re vie w and comparison of inte grated inducti v e-based h ybrid step u p DC-DC con v erters under continuous conduction mode (CCM). The paper contrib utes v aluable insights into the design and performance e v aluation of h ybrid con v erters. The authors’ w ork a ids in the under - standing of inte grated inducti v e based con v erters, of fering a basis for further adv ancements in DC-DC con v er - sion technology . Mo ving on to [33], authors introduce a no v el synchronized multipl e output DC-DC con v erter based on h ybrid yback-Cuk topologies. Their w ork addresses the need for ef cient and synchronized po wer con v ersion, pro viding a solution that combines the benets of yback and Cuk topologies. This no v el approach holds promise for enhancing the performance and reliability of DC-DC con v erters in v arious applications. Y an et al. [34], authors focus on adapti v e PI control for the speed re gulation of a DC motor . Their w ork introduces a reinforcement learning algorithm for adapti v e control, e xhibiting potential in achie ving precise and adaptable speed control for DC mo-tors. Mo ving be yond controller considerations, an in-depth analysis of v oltage and current stresses is important for a comprehensi v e e v aluation of the proposed h ybrid A C-DC con v erter . This process in v olv es e xploring stress f actors inherent in the con v erter’ s unique architecture and di v erse operational modes. In v estig ating v oltage stresses, which include peak and RMS v oltages, will pro vide crucial insights into their implications on o v erall performance and reliability . Simultaneously , current stresses in v olv e an assess- ment of peak and RMS current le v els, shedding light on potential challenges and optimizing the operational ef cienc y of the con v erter . Zeng et al. [35], authors present a DC capacitor -less in v erter for single-phase po wer con v ersion wit h minimized v oltage and current stress. Their w ork addresses the challenges associated with traditional DC capacitors in in v erters. The proposed solution of fers a promising alternati v e, minimizing stress on both v oltage and current in single-phase po wer con v ersion applications. Mahafzah et al. [36], contrib ute to the eld of in v erter reliability estimation by automating c o m ponent le v el st ress measurements. Their w ork focuses on adv ancing the methodologies for ass essing the reliability of in v erters. The authors’ automated stress measurement approach enhances the ef cienc y of reliability estimation, marking a signicant step forw ard in the eld of in v erter technology . 3. SIMULA TION RESUL TS This section presents the simulation results of the proposed con v erter , see Figure 6, v alidated using MA TLAB/Simulink R2020a. The maximum step size is set to 25 ms, and the solv er utilized is an ordinary dif ferential equation (ODE23tb) with a relati v e tolerance of 10 3 . W ith a simulation time of 1 s, the proposed con v erter is e xpected to reach a steady state. The simulation results for the proposed con v erter are elaborated upon in this section. P arameters are chosen based on the preceding discussion, with minor adjustments as outlined in T able 1, summarizing the parameters selected for the 4 . 5 kW po wer appl ication emplo yed in the simulation. These characteristics are suitable for v arious applications, including EVs adapters, micro-in v erter applications, and the inte gration of h ybrid rene w able ener gy resources with po wer systems. Figure 6. Ov erall simulated system An impr o ved hybrid A C to DC con verter suitable for electric vehicles applications (Khaled A. Mahafzah) Evaluation Warning : The document was created with Spire.PDF for Python.
1508 ISSN: 2502-4752 The simulated load v oltage and current are shoen in Figure 7. As sho wn, the load v oltage (Figure 7(a)) is a DC v oltage with v alue around 500 V with the ripple in the v oltage is about 12 %. The load current is adopted in Figure 7(b). It has the same beha vior as the load v oltage. The a v erage load current is about 8 . 5 A, which is suf cient to char ge the EV auxiliary system. Due to switching beha vior of the used con- v erter during char ging the auxiliary batteries of EVs from the electrical grid, this increases the nonlinear loads are connected to the grid. Therefore, the line current suf fers from high THD. The impro v ed h ybrid con v erter can operate as a po wer f actor correction topology because it is ability to form the line current and reduces its THD (see Figure 8). As e xpected, the impro v ed con v erter can form a nearly sinusoidal grid current w a v e, see Figure 8(a), with a THD within a standard (see IEEE-519). It can be seen from Figure 8(b) that the grid current has THD about 14 . 51 %. The indi vidual 3rd harmonics has the main contrib ution. It has a magnitude of 13 . 2 %. Ho we v er , if the used lter is optimally designed, this v alue will be further reduced. T able 1. Simulation parameters V ariable D escription V alue P in / P o Input/Output po wer 4 . 5 kW V in RMS grid v oltage 220 V -rms V o Output DC v oltage 500 V I o Output DC current 8 . 5 A a T ransformer ratio 350 / 1 , 000 C p SEPIC coupling capacitor 720 µ F L s 2 SEPIC second inductor 800 µ H C s SEPIC lter capacitor 520 µ F C f Flyback lter capacitor 720 µ F (a) (b) Figure 7. Simulated v oltage and current; (a) the load v oltage and (b) the load current (a) (b) Figure 8. Simulated line current and THD; (a) the grid current and (b) THD of the grid current 4. PO WER F A CT OR CORRECTION IN THE GRID CURRENT AND EFFICIENCY CALCULA- TION The po wer f actor of the grid current has become a main concern in recent years. Ho we v er , Figure 8(b) depicts THD of a grid current. The THD of the line current in Figure 8(a) is around 14 . 51 % when utilizing the f ast fourier transform (FFT) tool in MA TLAB. Due to inserting the auxiliary switches, the THD v alue has been reduced by about 3 % compared with THD of the grid current of the h ybrid SEPIC-Flyback con v e rter proposed in [22]. Indonesian J Elec Eng & Comp Sci, V ol. 39, No. 3, September 2025: 1499–1513 Evaluation Warning : The document was created with Spire.PDF for Python.