Voltage Overshoot Research Articles

Energy management of a DC microgrid with hybrid energy storage system using PI and ANN based hybrid controller

An energy management system incorporating a hybrid control scheme based on artificial neural networks (ANN)-based controller and a classical proportional–integral (PI) controller is proposed for a DC microgrid (DCMG) consisting of a fuel cell (FC) and a hybrid energy storage system (HESS) under variable load demand. The HESS incorporates a battery energy storage system (BESS) and a supercapacitor (SC) to cater high energy and high-power demands, respectively. The HESS with the proposed controller and energy management strategy (EMS) admits improved time response for sudden and slowly varying load demands, resulting in reduced battery stress with an improved battery life span. The microgrid configuration with a proposed hybrid controller is simulated on the Simulink® platform to establish its efficacy over a conventional controller. The proposed controller effectively minimises peak overshoot, settling time and deviation in DC bus voltage (DBV) , in comparison to the conventional one. Furthermore, simulation results are validated using a real-time OPAL-RT platform to ascertain effectiveness of the proposed strategy.

Seamless Transition and Fault-Ride-Through by Using a Fuzzy EO PID Controller in AVR System

One of the most crucial control aspects in electric power networks is ensuring constant voltage levels throughout different circumstances. To overcome this problem, an automatic voltage regulator (AVR) is installed in the electrical power networks to preserve the voltage at its allowable range. In this paper, a fuzzy-based PID controller was used to enhance the AVR dynamic performance under several operating conditions. Moreover, an Equilibrium Optimizer (EO) algorithm was used to initialize the controller gains. The validation of the proposed controller was proven through three different systems. The first was a simple AVR system under fixed and dynamic references. The proposed fuzzy EO PID controller proved its superiority in this case through the reduction of voltage overshoot by around 3–28% compared with the reported methods in the literature. Then, the fault-ride through capability of the proposed controller was proven through the second system, which was the Kundur two-area system suffering from a 3-phase fault condition, where the overshoot with the proposed controller was reduced by 4–7% compared with the default controller and modern weighted method reported in the literature. Lastly, an IEEE 9-bus system performance was tested with the proposed controller under normal, faulty, and dynamic loading conditions. Again, the proposed controller succeeded in reducing the maximum overshoot by around 5% compared with the default controller in the system. Moreover, the proposed controller achieved a seamless transition between the islanding and grid-connected mode of operation.

Performance Analysis and Comparison of Non-Inverting Buck-Boost Converter Using PI, OCC, and Hybrid OCC-PI Control

The study compares and analyses the performance of the one-cycle control (OCC), hybrid one-cycle-proportional integral control (OCC-PI), and the conventional PI control method applied to the non-inverting buck-boost converter. The hybrid OCC-PI control method combines the OCC and PI control techniques to provide a hybrid non-linear closed-loop control technique for regulating the buck-boost converter. The MATLAB/Simulink equivalent system model was simulated with design parameter variations using a wide input voltage range of 9 – 36 V, a nominal output voltage of 28 V, and a fixed switching frequency of 250 kHz to validate the control response speed, reliability, and robustness of the proposed control technique. The simulation results due to input voltage, output voltage, and load variations were carried out whiles recording the settling time, overshoots, efficiency, output voltage, and inductor current ripples due to each applied control technique. The simulation results indicated that the Hybrid OCC-PI control provides better response speed and a lower output voltage overshoot relative to the PI. It also provides better reference voltage tracking compared to the OCC control method.

Analysis, Design, and Experimental Results for a High-Frequency ZVZCS Galvanically Isolated PSFB DC-DC Converter over a Wide Operating Range Using GaN-HEMT

This paper investigates the potential of the emerging gallium nitride (GaN) high-electron mobility transistors (HEMT) power devices to meet certain power conversion challenges. The advantages of utilizing GaN HEMT transistors in a high-frequency, high-power isolated DC-DC topology are explored experimentally. Using the GaN HEMT’s parasitic elements, e.g., output capacitance, and the leakage inductance of the transformer, a soft switching zero-voltage zero-current switching (ZVZCS) phase shift converter is proposed. Accordingly, the freewheeling current is terminated, and soft switching is realized for most of the primary and secondary active devices. Furthermore, without using any additional circuitry, the overshoot voltage across the bridges of active rectifier diodes is clamped at their voltage level. In addition, a high-frequency power transformer is optimized to minimize the overall transformer losses (e.g., winding and core losses). Combined the conductor types, e.g., litz wire and copper foil, shows good electrical and thermal performance by reducing the AC and DC resistance. Finally, a 5 kW, 100–250 kHz prototype is built and tested. The experimental results show a conversion efficiency of up to 98.18% for the whole converter.

A Fast Transient Low-Dropout Regulator with High-Power Supply Rejection

With the continuous popularization of portable electronic products in electronic information, aerospace, biomedicine and other fields, low-dropout regulator (LDO) has become an important part of modern power management chips. Compared with other power management modules, it has the advantages of low power consumption, high power supply rejection, and strong anti-noise capability. However, the LDO power tube has a large width-to-length ratio, so when the load changes transiently, the gate of the power tube cannot respond in time, resulting in an overshoot and undershoot of the output voltage and a long recovery time. In this paper, the LDO transient enhancement circuit is designed. When the load changes transiently, the power tube gate capacitor is quickly charged and discharged, which overcomes the overshoot voltage and undershoot voltage. While improving the transient response of traditional LDO, the structure ensures the power supply rejection (PSR) and other performance of the circuit. According to the results, with an input of 2.5 V, the output voltage is regulated to 1.2 V, and PSR is -80 dB. When the load changes by 20 mA in 1 μs, it is stable within 1.2 μs while the undershoot voltage is controlled at 51 mV and the overshoot voltage is controlled at 65 mV.

Analysis of time‐frequency characteristic parameters of electromagnetic interference sources in the basic commutation unit

Establishing accurate electromagnetic interference (EMI) sources of the basic commutation unit is the key to accurately predicting the EMI of the converter equipment. To compensate for the insufficiency of the reported works, that is to use asymmetric trapezoidal waveforms (ATW) as common mode (CM) and differential mode (DM) EMI sources, this paper analyzed the switching transient process of insulated gate bipolar transistor (IGBT) device in the basic commutation unit, and then proposed the equivalent waveform of EMI sources with multi-polylines-damped oscillation waveform (MP-DOW). The spectrum envelop characteristic parameters of MP-DOW were obtained by the frequency domain analysis method, and its correctness was experimentally verified. Comparison with the reported works shows that the proposed spectrum envelope of MP-DOW can take into account the voltage and current overshoot during the switching transients of IGBT devices, and the spectrum characteristic parameters are more accurate. This paper is beneficial to the prediction of EMI for the converter already in operation, and can also provide theoretical guidance for the converter to be designed in conjunction with the analytical formula of the EMI source.

Intelligent control of integrated on-board charger with improved power quality and reduced charging transients

This paper proposes an intelligent control scheme for a two-stage integrated onboard electric vehicle (EV) battery charger connected to a single-phase household outlet which offers a close to ideal battery charging profile with power factor correction feature. Generally, the front-end AC–DC​ conversion stage is controlled by dual loop proportional–integral (PI) controllers, and tuning their gain constants is a difficult task. Furthermore, to achieve a close to ideal charging profile for an EV battery, the DC–DC conversion stage switches from constant current (CC) and constant voltage (CV) mode after a certain state of charge (SOC) which may lead to discontinuity in the charging current and voltage. This paper attempts to solve these issues by proposing an intelligent control scheme that includes the dynamic estimation of PI controller gain constants as well as provides a seamless mode transfer feature for battery charging. It is achieved by using fuzzy-PI-based control in the AC–DC conversion stage and Bayesian Regularization (BR) algorithm trained artificial neural network (ANN)-based control in the DC–DC conversion stage. The performance of the proposed control scheme is assessed both in steady-state and transient conditions in MATLAB® Simulink environment by comparing it against similar control schemes. The proposed intelligent control approach improves the dynamic response of DC link voltage, offers unity power factor operation and maintains the line current harmonics within IEEE 519 standards even during the switchover from CC to CV charging mode. Also, there is a decrease of 85% in the third harmonic component of the source current, 23.2% improvement in DC link voltage undershoot and 6.5% reduction in DC link voltage overshoot with reduced settling times using the proposed unified control scheme.

Small‐signal modelling considering internal perturbations for modular multilevel converters

Small-signal modelling of modular multilevel converters (MMC) has drawn lots of attention recently. Existing research mainly studies MMC terminal impedances by injecting corresponding AC-side and DC-side external small-signal perturbations. This paper focuses on the MMC internal small-signal perturbations, that is, perturbations in control signal and their effect. There are two kinds, that is, differential-mode and common-mode, of internal small-signal perturbations, which influence MMC external and internal state variables, respectively. Then, the existing MMC small-signal model is improved. With its help, accurate MMC control-signal to state-variables transfer functions are established, which can aid precise MMC controller analysis and performance optimization. In this paper, an analysis of MMC phase capacitor voltage regulation control is demonstrated as an example. The stability can be precisely ascertained based on the obtained transfer function. The effect of parameter variation of the proportional-integral controller is also studied. Moreover, an additional compensator is introduced in the existing control loop to attenuate resonance peaks in the transfer function, which mitigates the large voltage overshoot and makes the transient state much smoother. Simulation and experimental results support and well confirm the analysis of this paper.

An efficient switched inductor–capacitor‐based novel non‐isolated high gain SEPIC for solar energy applications

AbstractThe solar photovoltaic (PV) sources have low voltage output and hence cannot be used directly in micro‐grid applications. Therefore, to boost the low voltage output, a novel high gain single‐ended primary inductor converter (SEPIC) is proposed in this manuscript. The proposed high gain SEPIC (HGS) has an advantage of obtaining high voltage gain at a low duty ratio and continuous input current, which makes it viable for PV applications. The proposed converter offers simple control, and the high gain is obtained without the use of any transformer or coupled inductor so the semiconductor switch will not experience a voltage overshoot during the turn‐off operation. Hence, the conduction losses of the converter switch are reduced, and the performance of the converter is enhanced. Additionally, this manuscript also investigates the effectiveness of the proposed HGS in integration with the PV array. An extensive performance evaluation of the proposed HGS is investigated and compared with different SEPIC topologies in irradiance change conditions. Experimental implementation of the proposed HGS confirms the theoretical analysis and verifies the performance. Also, the real time (RT) analysis of the proposed HGS with PV array is conducted to show the validation of high gain operation for the PV application.

Main Circuit Topology and Electromagnetic Interference of Electric Vehicle Bidirectional Charger

In order to improve the electromagnetic compatibility performance of electric vehicle bidirectional chargers, the authors propose a main circuit topology and electromagnetic interference of the electric vehicle bidirectional charger. The design adopts the parallel connection of silicon carbide (SiC) MOSFETs and completes the bidirectional charging system based on the cascade connection of dual active bridge (DAB) and three-phase four-wire inverter. This paper mainly analyzes the influence of parasitic inductance on the drive and power loop of the T0-247 packaged switch in actual use, and according to the operating characteristics of the system, different gate resistors are used to reduce switching losses and improve system efficiency. And, we explore on how to reduce the overshoot voltage through the RC absorption circuit, thereby reducing the conducted interference. The result shows the following: the primary side absorption circuit resistance is 470 Ω and the capacitor is 47 nf, the secondary side absorption circuit resistance is 40 Ω and the capacitance is 4.7 nf, and the circuit power is 5000 W. Under the same conditions, without adding the RC absorption circuit, the conducted interference on the AC side does not meet the standard, and the amount of disturbance is large. After adding a suitable RC absorption circuit, the conducted interference on the AC side reaches the required value. Conclusion. This research provides a systematic design scheme and optimization method for designing power electronic devices using SiC.

An Improved Control Scheme for Reducing Circulating Current and Reverse Power of Bidirectional Phase-Shifted Full-Bridge Converter

Phase-shifted full-bridge (PSFB) converter is widely adopted in electric vehicle and energy storage applications. However, it suffers from serval technical drawbacks such as voltage overshoot, hard switching, severe circulating current, and large reverse power. To address such issues, an improved control scheme is proposed to enhance the performances of bidirectional operation in the PSFB converter. In this method, the precharge stage and the co-charge stage are added by adjusting the phase shift angle and duty ratio. The reverse power, circulating current and transformer Root Mean Square (RMS) Current can be reduced with the co-charge stage. Due to the precharge stage, this method can constrict voltage overshoot, while achieving zero current switching (ZCS) on the large current side devices and zero voltage switching (ZVS) on the high voltage side devices nearly along all the load range. The proposed method is described, analyzed, and validated in a 1 kW prototype which presents 96.1% peak efficiency and improves average efficiency by about 2% in the experimental results.

Improved Methodology for Parasitic Analysis of High-Performance Silicon Carbide Power Modules

The high edge rates of wide bandgap (WBG) semiconductors are known to excite resonances within device packaging, resulting in increased voltage overshoot and electromagnetic signatures. Simulation tools based on finite-element analysis (FEA) are commonly used during design to optimize device geometry and minimize parasitics. However, developing an accurate model to extract these parameters is challenging and requires an extensive understanding of the simulation environment. This article presents three custom power module geometries that are measured empirically and evaluated in COMSOL multiphysics. The included sensitivity analysis demonstrates that even a well-designed FEA model may offer poor predictions of module parasitics compared to empirical measurements. A virtual compensation procedure is then proposed that greatly improves the accuracy of the COMSOL FEA predictions by removing the contribution of the return path. This approach does not require empirical measurements to implement and can be applied generally to a variety of geometries. Finally, the technique is applied to a high-performance WBG power module, for which good agreement is demonstrated between empirical measurements and simulation predictions.

A PCB-Embedded 1.2 kV SiC MOSFET Half-Bridge Package for a 22 kW AC–DC Converter

This article presents the design and analysis of a double-side-cooled printed circuit board (PCB) embedded silicon carbide (SiC) MOSFET half-bridge package with low loop inductances and an integrated gate driver. The 1.2 kV SiC MOSFET dies used in the half-bridge package are embedded in the PCB using AT&S's patented technique. The dies are cooled and electrically connected to traces in the PCB through copper-filled microvias. The design methodology accounts for both electrical and thermal performance, limiting the power-loop inductance to 2.3 nH and the maximum package temperature to less than the 175 °C limit. The integration of the gate drive circuitry allows for a high power density and 2.2 nH gate-loop inductances. At 0.12 K/W, the measured junction-to-case thermal resistance with double-sided cooling is 57% lower than that of a TO-247 package. Under similar operating conditions, the PCB-embedded half-bridge package also achieves a 5.6 times lower voltage overshoot and a 0.5% higher peak efficiency than a TO-247-based half-bridge. This article reports the first demonstration of PCB-embedded 1.2 kV SiC MOSFET packages in buck, boost, and ac–dc converters. The prototype three-phase ac–dc converter for an electric vehicle on-board charger is composed of six PCB-embedded half-bridge packages and achieves an efficiency of 98.2% and a power density of 182 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> .

Research on the Voltage Spike Suppression Strategy for Three-Phase High Frequency Link Matrix-Type Inverter

The problem of high-voltage spikes on the secondary side of a high-frequency transformer (HFT) in the commutation process of a three-phase high-frequency link matrix-type inverter (HFLMI) is studied. Considering the parasitic capacitance of MOSFETs, the mechanism of voltage spikes during HFLMI commutation is revealed. According to the characteristics of the topology, the later stage matrix converter (MC) is decoupled into two groups of conventional three-phase voltage type inverters by the de-re-coupling idea, and the space vector pulsewidth modulation (SVPWM) is carried out, respectively. The zero vector is inserted between two nonzero voltage vectors to accomplish smooth commutation for addressing the problem of voltage overshoot on the secondary side of HFT due to the switching of HFT leakage inductance and filter inductance to the same path. Due to the existence of parasitic capacitance, the voltage spikes caused by its resonance with the system’s stray inductance cannot be solved by optimizing modulation strategies. In order to further suppress voltage spikes, a flyback clamp circuit is proposed to absorb the leakage inductance energy. Ultimately, a prototype with a rated power of 200 W is developed for experimental verification. The results show that the peak efficiency of three-phase HFLMI with the flyback clamp circuit is 92.6% in the full power range, the voltage spikes on the secondary side of HFT are clamped to about 1.2 times the rated voltage, and all switches realize soft-switching.

Energy management and control for direct current microgrid with composite energy storage system using combined cuckoo search algorithm and neural network

This paper describes a novel energy management strategy (EMS) based on a combined cuckoo search algorithm and neural network (CCSNN) for the control of a DC microgrid (DCMG) with composite energy storage system (CESS). The presented control technique intends to enhance the power-sharing between batteries and supercapacitors (SCs) in order to handle the demand-generation discrepancy, preserve state-of-charge (SOC) inside predetermined parameters, and manage DC bus voltage (DBV). Furthermore, the efficacy of the suggested technique for enactment in terms of voltage overshoot and settling time was compared to conventional control strategy-based findings. The results are validated by experimental studies employing a hardware-in-loop (HIL) configuration on an FPGA-based real-time simulator.

A Capacitorless Flipped Voltage Follower LDO with Fast Transient Using Dynamic Bias

The output capacitorless low-dropout regulator (OCL-LDO) has developed rapidly in recent years. This paper presents a flipped voltage follower (FVF) OCL-LDO with fast transient response. By adding a dynamic bias circuit to the FVF circuit, the proposed LDO has the ability to quickly adjust the gate voltage of the power transistor, without extra power consumption. The proposed LDO was designed in 0.18 μm CMOS process. The simulation results show that the recovery time is 52 ns when the load changes from 0.1 mA to 20 mA with a slew rate of 20 mA/ps, while the quiescent current is 92 μA with 1 V regulated output. The undershoot and overshoot voltage are 242 mV and 250 mV, respectively.

Design for Reliability of SiC-MOSFET-Based 1500-V PV Inverters With Variable Gate Resistance

1500-V photovoltaic (PV) configuration is the standard design in the solar PV industry. Extending the maximum dc voltage from 1000 to 1500 V can reduce the installation cost of the entire power plant. However, it may affect the reliability of the corresponding 1500-V PV inverters, due to the increased loading stresses, i.e., voltage stress and thermal loading of power devices. In this context, this article proposes a solution to the reliability enhancement of silicon carbide- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> -based 1500-V PV inverters with variable gate resistance. This solution offers a possibility to adaptively adjust the switching speed to make a compromise between the switching power loss and voltage overshoot during commutation, thus enhancing the reliability. The evaluation results based on the mission profile of a 125-kW 1500-V PV system installed in Denmark indicate that the PV inverter with the proposed design, i.e., variable gate resistance, can improve reliability performance compared to the fixed gate resistance solution while ensuring a safer operating voltage margin.

Optimal energy management of a photovoltaic-batteries-grid system

Microgrid becomes an attractive concept to meet the rapidly increasing demands for energy in worldwide and deal with air pollutions. Distributed energy resources (DERs) in Microgrid are the vital role to meet the demand of the grid locally. The performance and the PV source grid connected system's response depend on vital parameters like transient response, voltage or current overshoot, steady state error, and harmonics distortions. This research aims to optimize the proportional-integral (PI) controller for improving power quality performance and energy management of the PV battery of three phase inverter of grid connected mode scheme. Besides to the PI conventional method, three different meta-heuristic optimization algorithms are proposed and implemented in order to enhance the PI and hence all system parameters. These three algorithms are (Particle Swarm Optimization (PSO), Whale Optimization Algorithm (WOA), Dragonfly Algorithm (DA)) that can tune the PI controller's parameters by minimizing voltage regulator error, hence approving the goal of optimization in finding the optimal local or global solutions. The experimental results have been demonstrating the variety and the effectiveness of these optimization methods in convergence generation, computation time, and improving all required system parameters.

A Novel GaN-Based Solid-State Circuit Breaker With Voltage Overshoot Suppression

This article proposes a novel ultra-fast self-powered bidirectional solid-state circuit breaker (SSCB) with voltage overshoot suppression that uses gallium nitride switches with very low conduction losses. This SSCB can be used in low and medium ac/dc networks for both short-circuit protection and overcurrent protection. An exhaustive methodology for RCD snubber design applied to SSCBs is provided. A comprehensive review of the technical literature is presented exhibiting that the proposed SSCB reduces conduction losses and detection time in comparison with other similar SSCBs. The performance features of the proposed SSCB are verified through the functional tests that are carried out employing a hardware-implemented prototype. Experimental results confirm that our proposal is able to detect and process the short-circuit failure in 282 ns; the authors have not found any faster results in the literature.

A Germanium Based Quantum Well Complementary Metal-Oxide-Semiconductor Transistor

Germanium is recognized as an important prospective material due to its great carrier mobility. The current design and research of GeSn channel field effect transistors are far from mature. Especially the complementary Ge-based CMOS device is rarely reported. It significantly limits the application and development of Ge-based MOS technology. Based on this, a Si0.2Ge0.66Sn0.14-Ge0.82Sn0.18-Ge double heterojunction quantum well NMOS and PMOS are proposed. Benefiting from the high carrier mobility of Ge and the increased mobility brought by the quantum well, the proposed NMOS and PMOS device achieves mA level output current at 1 V gate bias, and the surface channel is significantly suppressed. Based on quantum well NMOS and PMOS, a new CMOS device compatible with the Si process is constructed. The quantum well CMOS inverter has a faster voltage conversion rate, a 4-fold reduction in propagation delay, a 10% reduction in output overshoot voltage, and a more robust driving capability than the Si-based CMOS inverter.