Showing papers on "Voltage regulator published in 2020"
TL;DR: The obtained results show that the proposed controller fulfilled the recent standard requirements in mitigating power quality (PQ) events, and can increase the effort towards the development of smooth PVPP integration by optimizing the design, operation and control strategies towards high PQ and green electricity.
Abstract: The generation and integration of photovoltaic power plants (PVPPs) into the utility grid have increased dramatically over the past two decades. In this sense, and to ensure a high quality of the PVPPs generated power as well as a contribution on the power system security and stability, some of the new power quality requirements imposed by different grid codes and standards in order to regulate the installation of PVPPs and ensure the grid stability. This study aims to investigate the recent integration requirements including voltage sag, voltage flicker, harmonics, voltage unbalance, and frequency variation. Additionally, compliance controls and methods to fulfill these requirements are developed. In line with this, a large-scale three-phase grid-connected PVPP is designed. A modified inverter controller without the use of any extra device is designed to mitigate the sage incidence and achieve the low-voltage ride-through requirement. It can efficiently operate at normal conditions and once sag or faults are detected, it can change the mode of operation and inject a reactive current based on the sag depth. A dynamic voltage regulator and its controller are also designed to control the voltage flicker, fluctuation, and unbalance at the point of common coupling between the PVPP and the grid. The voltage and current harmonics are reduced below the specified limits using proper design and a RLC filter. The obtained results show that the proposed controller fulfilled the recent standard requirements in mitigating power quality (PQ) events. Thus, this study can increase the effort towards the development of smooth PVPP integration by optimizing the design, operation and control strategies towards high PQ and green electricity.
66 citations
TL;DR: In this paper, the authors derived the ac-side impedance matrices (IMs) of the MMC with the open-loop and closed-loop voltage control and their relationship is also explicitly given.
Abstract: This paper addresses the small-signal stability of voltage-controlled modular multilevel converters (MMCs) feeding linear ac systems. By using the harmonic state-space (HSS) modeling method, the ac-side impedance matrices (IMs) of the MMC with the open-loop and closed-loop voltage control are derived and their relationship is also explicitly given. It is revealed that the ac voltage regulator has the same effect on the centered diagonal element of the IM of the MMC as that of two-level voltage-source converters (VSCs). Moreover, when the MMC is feeding linear ac loads, the return-ratio matrix of the cascaded system has an eigenvalue that is equal to the ratio between the centered diagonal element of the IM of the MMC and the load impedance, which, consequently, facilitates the stability evaluation by checking that single-input single-output impedance ratio as a necessary condition. These findings also provide physical insights into the subsynchronous oscillation (SSO) of the voltage-controlled MMC with the proportional-resonant (PR) regulator, and a proportional-integral-resonant (PIR) regulator is further introduced to mitigate the SSO. Finally, time-domain simulations verify the effectiveness of the theoretical analysis.
63 citations
TL;DR: It has been revealed that the proposed TSA-based PID controller improves tracking properties under load change thus it can be effectively used for synchronous generator automatic voltage regulator terminal voltage stability.
Abstract: In this study, an optimal Tree-Seed Algorithm (TSA) algorithm-based Proportional-Integral-Derivative (PID) controller is proposed for automatic voltage regulator (AVR) system terminal tracking problem. PID controller gains Kp, Ki, and Kd are optimized with the proposed TSA algorithm based on different objective functions. The TSA-based optimal PID controller's performance is compared with numerous PID controllers, which were developed using different meta-hermetic optimization algorithms in the literature. Several analysis methods including root locus, bode analysis, robustness, and disturbance rejection are studied and compared with reported works in the literature. It is shown that there is still a research gap to improve the tracking performance of the AVR system due to its importance in electrical systems. According to the obtained comparison results, it has been revealed that the proposed TSA-based PID controller improves tracking properties under load change thus it can be effectively used for synchronous generator automatic voltage regulator terminal voltage stability.
54 citations
TL;DR: A double-time-scale coordinated voltage control scheme for distribution networks with distributed generators (DGs) based on model predictive control (MPC) to regulate the voltage profile across a network to capture more renewable energy.
Abstract: This paper proposes a double-time-scale coordinated voltage control scheme for distribution networks with distributed generators (DGs) based on model predictive control (MPC) to regulate the voltage profile across a network. The slow-time-scale control scheme is designed to correct long-term voltage deviations while reducing the number of actions of the on-load tap changer, step voltage regulators, and capacitor banks. The MPC problem is formulated as a mixed-integer quadratic programming (MIQP). A tailored exaction solution method based on the branch-and-bound algorithm embedded with an alternating direction method of multiplier-based QP solver is developed to efficiently solve the MIQP problem. In the fast-time-scale control, the active and reactive power outputs of DGs are optimally coordinated to handle the fast voltage fluctuations as well as capture more renewable energy. An efficient analytical sensitivity calculation method is used to update the voltage sensitivities online. The effectiveness of the proposed control scheme along with the exact solution method is verified on a modified real 20 kV distribution system.
50 citations
TL;DR: A droop-free distributed cooperative control with precisely regulated voltage variance and admissible voltage profile guarantees for AC microgrids is proposed and it is shown that the steady-state solution of the proposed control can be obtained by solving a set of nonlinear equations.
Abstract: In this paper, we propose a droop-free distributed cooperative control with precisely regulated voltage variance and admissible voltage profile guarantees for AC microgrids. First a distributed voltage variance observer is proposed and proven to be able to converge to global voltage variance using only local measurements and information from neighboring distributed generators (DGs). A droop-free distributed control with average voltage regulator, voltage variance regulator, and relaxed reactive power regulator is then designed and shown to be able to achieve the regulation of average voltage and voltage variance and relaxed reactive power sharing in steady-state. For relaxed reactive power sharing, one special DG that could be a community-owned or utility-owned DG will not participate in reactive power sharing and this flexibility is utilized to regulate the voltage profile. The small-signal stability of the system with the proposed control is evaluated by measurement-based Prony analysis, which can also guide the control parameter selection. It is also shown that the steady-state solution of the proposed control can be obtained by solving a set of nonlinear equations, which allows more efficient evaluation of the control performance under different operating conditions and various controller settings. To validate the performance of the proposed control, extensive real-time simulation studies are performed in OPAL-RT on a four-DG test microgrid.
46 citations
01 Jul 2020
TL;DR: In this article, the principle of operation of an optoelectronic voltage relay for switching windings of a boost voltage transformer of a voltage stabilizer was discussed, and it was determined that the change in the shape of the output voltage curve is close to a sinusoid and coincides with the results obtained by the experimental path.
Abstract: The article discusses the principle of operation of an optoelectronic voltage relay for switching windings of a boost voltage transformer of a voltage stabilizer. Based on the simulation of the proposed optoelectronic contactless voltage stabilizer using the MATLAB R2014a program, it was determined that the change in the shape of the output voltage curve is close to a sinusoid and coincides with the results obtained by the experimental path. When modeling a voltage stabilizer, the structure of the circuit does not change, but the parameters of the resistor elements corresponding to the open or closed state of the semiconductor device at the time of switching the vents change. The characteristic of voltage changes "input-output" and the analysis of existing voltage stabilizers on the principle of "quality voltage" in rural areas
40 citations
TL;DR: The results show that the proposed voltage control strategy can optimally and effectively manage the voltage regulators in the UDS, which decrease their operation stresses and minimize the overall voltage deviation.
Abstract: The rapid increase in the installation of renewable energy sources, particularly solar photovoltaic (PV) sources associated with unbalanced features of distribution systems (DS), disturbs the classic control strategy of voltage regulation devices and causes voltage violation problems. This paper proposes an effective control strategy for voltage regulators in the DS based on the voltage sensitivity using a multi-agent system (MAS) architecture. The features of the unbalanced distribution system (UDS) with the PV and different types and configurations of voltage regulators are considered in the proposed strategy. The novelty of the proposed method lies in realizing both the control optimality of minimizing voltage violations and the flexibility to accommodate changes in the DS topology using an MAS scheme. An advantageous feature of using the MAS scheme is the robust control performance in normal operation and against system failure. Simulation studies have been conducted using IEEE 34-node and 123-node distribution test feeders considering high PV penetration and different sun profiles. The results show that the proposed voltage control strategy can optimally and effectively manage the voltage regulators in the UDS, which decrease their operation stresses and minimize the overall voltage deviation.
37 citations
01 Feb 2020
TL;DR: This work embraces current-domain ‘signature attenuation’ (CDSA) as a low-overhead generic countermeasure against both EM and power side-channel attacks to achieve the highest minimum traces to disclosure (MTD) reported to date.
Abstract: Computationally-secure cryptographic algorithms when implemented on physical platforms leak critical physical signals correlated with the secret key in the form of power consumption and electromagnetic (EM) emanations. This can be exploited by an adversary, leading to side-channel attacks (SCA) that can recover the secret key. Circuit-level on-chip countermeasures include a switched-capacitor current equalizer [1], charge-recovery logic [2], an integrated voltage regulator (IVR) [3], and an all-digital low-dropout (LDO) regulator [4], which suffer from performance degradation, high power/area overheads because of large embedded passives, as well as EM leakage from large metal-insulator-metal (MIM) capacitor top plates. Alternatively, simulations of shunt LDO-based regulators have been shown to be effective for power SCA resistance [5]. Noting that the correlated current is the source of both power (at supply pin) and EM leakage (radiation throughout current path), this work embraces current-domain ‘signature attenuation’ (CDSA) as a low-overhead generic countermeasure against both EM and power side-channel attacks to achieve the highest minimum traces to disclosure (MTD $> 1\mathrm{B})$ reported to date.
35 citations
TL;DR: It is revealed that the proposed controller can be considered as a significant device in the subject area of the power systems as it offers, more energy efficient, robust, and fast convergence characteristics than the controllers.
Abstract: This paper presents a new design technique to determine the optimal values of proportional-integral-derivative controller gains of an automatic voltage regulator, using the evolutionary algorithm namely 'Cuckoo Search'. The dynamic performance of the proposed controller is evaluated by estimating its transient response characteristics, such as, rise time, settling time, maximum peak overshoot, and steady-state error. In addition, a thorough comparison of the time response characteristics, obtained with proposed controller and other existing evolutionary algorithm based controllers is made to demonstrate its external attributes and adeptness. Comparative analysis illustrates that the proposed controller can be considered as a significant device in the subject area of the power systems as it offers, more energy efficient, robust, and fast convergence characteristics than the controllers, considered here for the discussions. Furthermore, robustness of proposed controller has also been investigated by allowing 50% uncertainty in the automatic voltage regulator system. Finally, the stability of an automatic voltage regulator system with proposed controller is investigated through root-locus and bode plots. It is revealed that the proposed controller not only capable to provide good dynamic response, but also exhibits stable performance for wide range of open loop gains.
34 citations
TL;DR: A modified binary gray wolf optimization (MBGWO) algorithm has been proposed and in association with PVSI droop control has been employed to control the voltage violations during cloudy day condition and for service restoration considering voltage regulation and peak demand reduction under faulty condition.
Abstract: Reduction of energy consumption and energy losses is a major concern of the distribution network operator in the present scenario. Traditionally, on-load tap changers, a shunt capacitor bank, and a voltage regulator have been employed as volt-var control (VVC) devices for savings in energy consumption and losses. In this paper, an efficient and optimally coordinated operation of traditional VVC devices, a distribution network reconfiguration (DNR), and a photovoltaic smart inverter (PVSI) for energy savings has been proposed. In order to achieve the optimal solution, a modified binary gray wolf optimization (MBGWO) algorithm has been proposed. Besides, the proposed method in association with PVSI droop control has been employed to control the voltage violations during cloudy day condition. Furthermore, the proposed method has been employed for service restoration considering voltage regulation and peak demand reduction under faulty condition. For validation, the performance of the proposed algorithm has been tested on balanced as well as unbalanced distribution systems. The test results demonstrate the significance of the DNR associated with VVC devices and PVSI for energy savings under different load models. Outcome of the proposed algorithm has been compared with other existing metaheuristic algorithms and test results demonstrate the benefit of the proposed method.
31 citations
TL;DR: A hierarchical-hybrid architecture for Volt/Var control of distribution grids in the presence of high penetration of distributed generators (DGs), which includes three layers with specific operational goals associated with each layer based on data resolution, communication network, and control device response time is presented.
Abstract: This paper presents a hierarchical-hybrid architecture for Volt/Var control of distribution grids in the presence of high penetration of distributed generators (DGs). The architecture includes three layers with specific operational goals associated with each layer based on data resolution, communication network, and control device response time. The top layer carries out central optimization and seeks to minimize power losses via optimal 15-minute scheduling of load tap changers (LTCs), voltage regulators (VRs), and capacitor banks (CBs), and DGs. The middle layer ensures voltage regulation using a distributed approach for reactive power provisioning by fast response DGs. The bottom layer carries out local decision making that enlists edge intelligence to operate LTCs, VRs and CBs to cope with fast and real-time changes in DGs and loads. The top layer generates overall references for the lower layers optimized over a 24-hour horizon, updated at 15-minute intervals, which are then suitably corrected at faster time-scales of seconds in the middle and bottom layers. Appropriate coordination is introduced between each layer so as to meet combined goals of optimization and accommodation of load and generation uncertainties in near real-time. The proposed method is validated using a modified IEEE 34 bus test feeder and at 80% penetration of DGs.
TL;DR: The comprehensive study carried out in this paper implies that ICA optimized controller operates properly and has proven its robustness for ± 10% variations in system parameters and physical constraints.
TL;DR: It is too complicated to design a decoupling control structure that can eliminate the dynamic interference of IVSRs to OVRs by using traditional control strategies, so the two controllers can be independently designed.
Abstract: This paper proposes a novel input voltage balancing control strategy for dual-active-bridge (DAB) input-series-output-parallel (ISOP) DC-DC converters. The proposed strategy not only aims at balancing the input voltage among modules but also at eliminating the coupling effect between input voltage sharing regulators (IVSR) and output voltage regulators (OVR). Specifically, this paper reveals it is too complicated to design a decoupling control structure that can eliminate the dynamic interference of IVSRs to OVRs by using traditional control strategies. Thus, an intermediate control variable, which was adjusted by the IVSR and OVR to simplify the decoupling control structure design, was introduced to calculate the phase-shift ratio. Furthermore, a new control law was derived, and an expression for the intermediate control variable modification was proposed to achieve decoupling control. Moreover, to complete the discussion, the main transfer functions were deduced and the design procedure was illustrated. Based on the novel control strategy, the interference of an IVSR to an OVR was eliminated, so the two controllers can be independently designed. Finally, both the simulation and experimental results were used to verify the performance of the novel control strategy.
TL;DR: The proposed Improved Whale Optimization Algorithm benefits from an evolutionary operator crossover to promote the diversity of solutions while maintaining a reasonable local search behavior and reliably outperforms most of the current techniques.
Abstract: The paper proposes an Improved Whale Optimization Algorithm (IWOA). Its performance is validated by solving 23 benchmark functions. Comparing the results of IWOA with well-known meta-heuristic algo...
TL;DR: This dual inductor hybrid (DIH) converter features a smaller number of switches and more effective switch utilization than a recently reported hybrid Dickson converter, yielding substantially less switch losses represented by smaller volt–ampere products and smaller equivalent output resistance.
Abstract: Achieving high-efficiency power conversion with high power density for a large conversion ratio is crucially needed yet challenging in point-of-load applications because of increasing demands of loads. This article presents a new hybrid converter to address this need. The converter uses two interleaved inductors for complete soft charging of flying capacitors to provide high output currents with no capacitor hard-charge loss. This dual inductor hybrid (DIH) converter features a smaller number of switches and more effective switch utilization than a recently reported hybrid Dickson converter, yielding substantially less switch losses represented by smaller volt–ampere products and smaller equivalent output resistance. Converter operation principle is analyzed in detail to confirm the feasibility and benefits, and design considerations are provided to identify a practical design process. Experimental results verify the converter's operation principles and advantages with a 300-kHz 20-W prototype achieving 95.02% peak efficiency and 225-W/in3 power density. The converter's advantages and performance make the point-of-load converter architecture a good candidate for demanding applications, such as in data centers, telecommunications, and high-performance digital systems.
TL;DR: Time-domain simulations demonstrate the robustness and appropriate performance of the proposed decentralized control under different large disturbances.
Abstract: This paper proposes an interconnection and damping assignment passivity-based control (IDA-PBC) for multimachine power systems including hydro-turbine governing systems (HTGS) with surge tank. The main objective is to stabilize the rotor speed and regulate the terminal voltage of each synchronous machine in a power system. The proposed control is decentralized, thus avoiding challenges of communication between generators. Passivity theory is used since the open-loop of the HTGS presents a port-Hamiltonian structure. IDA-PBC allows a control law that maintains the passive structure in closed-loop, guaranteeing its asymptotic stability using Lyapunov's theory. The dynamics of each HTGS are described by an eleventh-order model, which can be reduced to a tenth-order. The proposed control is tested in a 12-bus test system and compared to a standard control, which considers a voltage regulator and exciter based on the IEEE type ST1A excitation system model and power system stabilizer IEEE-PSS1A. The governing system based on a PID control with static and transient droop is also employed. Additionally, the proposed controller is compared to a sliding mode controller. Time-domain simulations demonstrate the robustness and appropriate performance of the proposed decentralized control under different large disturbances.
01 Feb 2020
TL;DR: A fully synthesizable, Distributed, and scalable all-Digital LDO (D-DLDO) voltage regulator with the following salient features: (1) fast single-cycle voltage monitoring using a Digital Supply-Voltage Sensor (DSVS), (2) fast digital PID-based controller, and (3) APR-friendly and tile-able design without the need to generate or route any global or inter-LDO digital/analog signals.
Abstract: Integrated LDOs cost-effectively enable fine-grain voltage regulation for digital IP blocks. A distributed LDO architecture, where a number of dispersed LDO units supply a single domain with shared power delivery network (PDN), has been recently proposed for point-of-load regulation improving both local IR-drop and transient droop response across the IP domain [1]–[3]. However, previous distributed LDOs used custom communication between a global controller and local distributed LDO controllers [1], custom communication between neighboring LDO controllers [2], and/or analog voltage sensors with associated shared $\mathrm{V}_{\mathrm{REF}}$ generation and routing [1]–[3]. This paper presents a fully synthesizable, Distributed, and scalable all-Digital LDO (D-DLDO) voltage regulator (Fig. 25.1.1) with the following salient features: (1) fast single-cycle voltage monitoring using a Digital Supply-Voltage Sensor (DSVS), (2) fast digital PID-based controller, and (3) APR-friendly and tile-able design without the need to generate or route any global or inter-LDO digital/analog signals. A test-chip is implemented with 9 DLDO units in 10nm CMOS (Fig. 25.1.7). Each DLDO unit, including its power gates (PGs), DSVS, and controller, was fully synthesized using standard library cells and industry-standard automatic placement-and-routing (APR) tools.
TL;DR: It is proven that the proposed voltage-mode SO-SMC controller has a superior performance and it increases efficiency in the extraction of maximum power from WECS with the fast and robust voltage tracking.
TL;DR: The proposed controller works on adaptive droop and voltage shifting technique, which equalises the current sharing whether line resistances are similar or not and controls each output voltage to follow the respective bus reference voltage.
Abstract: DC microgrid is becoming popular because of its high efficiency, high reliability and connection of distributed generation with energy storage devices and dc loads. The main objective in the dc microgrid is to keep the dc bus voltage constant and equalise per unit current sharing among converters. The conventional droop control is used to equalise per unit current sharing similar to reactive power sharing in an ac microgrid. Nevertheless, the problem in conventional droop control is that equal current leads to a reduction of dc bus reference voltage and voltage regulation becoming unequal across each node due to unequal line resistance drop. The proposed controller works on adaptive droop and voltage shifting technique, which equalises the current sharing whether line resistances are similar or not and controls each output voltage to follow the respective bus reference voltage. The isolated dc–dc converters are used to simulate and validate the proposed control technique.
TL;DR: In this paper, a smoothing solution that modulates HVAC power in response to volatile PV generation is presented to mitigate fluctuations in the net demand and generation, which can be considered as flexible loads due to the inherent building thermal inertia.
TL;DR: A novel gain adaptation for the voltage regulator, the F-W behavior is decoupled from the speed control response at speed steady-state (at constant or slowly changing torque), improving performance of the overall drive control.
Abstract: Flux-weakening (F-W) based on feedback voltage regulation is commonly adopted in interior permanent magnet synchronous motor drives. Voltage space vector magnitude is controlled in a closed loop, modifying the current reference, following a value related to the inverter limitations. A stable and fast voltage control allows to operate with lower voltage margin, leading to higher torque versus speed capability. Theoretical analysis and gain adaptation of the F-W regulation loop was reported by Bolognani et al . partially overcoming the difficulties due to the strong nonlinearity of the plant. An approximated closed-form design method was proposed and refined by Bedetti et al . This allowed the application of the algorithm to drives where autotuning is needed, ensuring stability and dynamical performances. A fundamental enhancement is introduced in this article, namely the use of a speed regulator with explicit torque reference output. An advantage of this technique is that the speed loop becomes linear in the whole operating range and an accurate control of machine torque is possible. Thanks to a novel gain adaptation for the voltage regulator, the F-W behavior is decoupled from the speed control response at speed steady-state (at constant or slowly changing torque), improving performance of the overall drive control. Adoption of this novel method allows smooth operation with invariant dynamical behavior of both the speed and F-W control loops. Extensive simulations and experimental tests are reported to prove the validity of the proposal. A sensorless operation of the drive system has also been considered in the tests to further validate the proposed solution.
TL;DR: An optimal voltage regulator (OVR) is proposed for controlling IIDG units to achieve a free/wide range of impedance shaping and facilitates the optimal impedance shaping based on the control requirement and grid's impedance characteristics, which makes the I IDG units consistent with the power network thus contributing to stabilizing modern power systems.
Abstract: The stable operation of conventional power systems greatly depends on coherent impedances of the bulk power networks’ elements. However, penetration of inverter interfaced distributed generation (IIDG) units put the stability of modern power systems into a risk due the vague and arbitrary output impedance of IIDG units. Besides, the impedance specification of IIDGs can only be established by means of a virtual impedance loop, which needs extra control efforts also imposes voltage drops. Especially, the virtual impedance depends on the output current and cannot be thus freely adjusted. To this end, an optimal voltage regulator (OVR) is proposed for controlling IIDG units to achieve a free/wide range of impedance shaping. The OVR facilitates the optimal impedance shaping based on the control requirement and grid's impedance characteristics, which makes the IIDG units consistent with the power network thus contributing to stabilizing modern power systems. The OVR's control system is based on the state feedback control and the impedance shaping is achieved through an appropriate feedback gain adjustment process. Simulation results prove the effectiveness of the method to achieve the desired impedance shaping.
13 Apr 2020-Compel-the International Journal for Computation and Mathematics in Electrical and Electronic Engineering
TL;DR: In a power system, the purpose of automatic voltage regulator (AVR) is the voltage control of synchronous generator that depends on the AVR.
Abstract: In a power system, the purpose of automatic voltage regulator (AVR) is the voltage control of synchronous generator. Power system stability and security depends on the AVR.
15 Mar 2020
TL;DR: In this paper, a design of 1 MHz isolated auxiliary power supply system using gallium nitride (GaN) devices with medium voltage insulation reinforcement is presented, which is capable to simultaneously supply multiple gate drivers and auxiliary components for 10 kV silicon carbide (SiC) MOSFETs based converter systems with a strong high dv/dt common-mode noise immunity.
Abstract: This paper presents a design of 1 MHz isolated auxiliary power supply system using gallium nitride (GaN) devices with medium voltage insulation reinforcement The designed power supply is capable to simultaneously supply multiple gate drivers and auxiliary components for 10 kV silicon carbide (SiC) MOSFETs based converter systems with a strong high dv/dt common-mode noise immunity In the system, a highfrequency soft-switched resonant topology and current-fed switching voltage regulator are applied to the power supplies sending and receiving sides respectively To achieve medium voltage insulation (PD free) as well as low coupling capacitor (<2 pF) of the system, a current based transformer with single turn on the sending side is designed This complete auxiliary power supply design is capable of driving more than 6 distributed loads with total power of 120 W under different conditions and it is immune to load failures
TL;DR: Within this work, a novel controller in terms of H infinity (H∞) and structured singular value decomposition has been presented to provide the robust performance of the Automatic Voltage Regulator (AVR) system.
Abstract: Within this work, a novel controller in terms of H infinity ( H ∞ ) and structured singular value decomposition has been presented to provide the robust performance of the Automatic Voltage Regulator (AVR) system Six real structured uncertainties in actuator, exciter and generator have been assumed for the linear transfer functions of the AVR system. Each uncertain parameter varies between a minimum and a maximum value due to the load variations in a period of time and aging effects over the life time. The efficiency of the presented design lies on two main reasons. The first is the simultaneous considering of the output disturbances, sensor noises and system uncertainties in the controller design approach. The second is the non-conservative modeling of all six structured parameters in the required μ -synthesis P − Δ − K configuration. By suboptimal H ∞ control design technique and μ -analysis theorem, a single input single output (SISO) controller comprising a closed loop system with μ
TL;DR: Experimental results show that the fast energy recovery of the on-chip solar cell and PMU permits the system to replenish the supercapacitor with enough charge as to sustain Bluetooth Low Energy (BLE) communications even with input light powers of 510 nW.
Abstract: This paper presents experimental results from a system that comprises a fully autonomous energy harvester with a solar cell of 1 mm2 as energy transducer and a Power Management Unit (PMU) on the same silicon substrate, and an output voltage regulator. Both chips are implemented in standard $0.18~\mu \text{m}$ CMOS technology with total layout areas of 1.575 mm2 and 0.0126 mm2, respectively. The system also contains an off-the-shelf 3.2 mm $\times2.5$ mm $\times0.9$ mm supercapacitor working as an off-chip battery or energy reservoir between the PMU and the voltage regulator. Experimental results show that the fast energy recovery of the on-chip solar cell and PMU permits the system to replenish the supercapacitor with enough charge as to sustain Bluetooth Low Energy (BLE) communications even with input light powers of 510 nW. The whole system is able to self-start-up without external mechanisms at 340 nW. This work is the first step towards a self-supplied sensor node with processing and communication capabilities. The small form factor and ultra-low power consumption of the system components is in compliance with biomedical applications requirements.
TL;DR: The proposed MO-VVC reduces the power loss by adjusting capacitor banks switches, tap position of on-load tap changer transformers, voltage regulators’ taps, and active and reactive power set-points of P-DERs.
TL;DR: A novel shunt regulator with only one output diode and a protection strategy to achieve high efficiency, appropriate shunt current limitation, and low turn-off delay is proposed and an innovative self-retriggerable diode short-circuit fault detector circuit is proposed.
Abstract: Sequential switching shunt regulators (S3Rs) are widely used in the satellites owing to their simple structure and high reliability. The high-power communication satellites require a power supply with a high bus voltage and large solar array section current. However, a large solar array capacitance and new time-division multiple access operations complicate the design of a lightweight and cost-effective power supply by increasing the difficulty in dissipation and thermal control. On the basis of passive current limitation, in this article, we propose a novel shunt regulator with only one output diode and a protection strategy to achieve high efficiency, appropriate shunt current limitation, and low turn- off delay. In addition, to reduce the dissipation of an S3R cell when feeding the solar array current to the main bus and to satisfy the single point failure-free requirement, an innovative self-retriggerable diode short-circuit fault detector circuit is proposed, which includes a protection switch for a safe thermal or electrical operation. Finally, simulation and experimental results are presented to validate the proposed shunt regulator and the corresponding control method or protection strategy.
01 Jun 2020
TL;DR: The simulation results have showed that the performance of the proposed HGSO-FOPID controller is better than SSA-FopID, SFS-Pid, and IKA-PID controllers.
Abstract: Henry gas solubility optimization (HGSO) algorithm is proposed for terminal voltage control of a generator in an automatic voltage regulator (AVR) system using a fractional order proportional–integral–derivative (FOPID) controller. The proposed technique was utilized for obtaining optimal parameters of FOPID by minimizing a time domain objective function. The box plot and convergence analyses were carried out in order to show the efficiency of the proposed approach. The performance of HGSO-based FOPID controller (HGSO-FOPID) compared with salp swarm algorithm based FOPID (SSA-FOPID) controller, stochastic fractal search algorithm based PID (SFS-PID) and improved kidney algorithm based PID (IKA-PID) controllers via transient and frequency response analyses. The simulation results have showed that the performance of the proposed HGSO-FOPID controller is better than SSA-FOPID, SFS-PID, and IKA-PID controllers.
TL;DR: In this article, the use of magnetic thin-film inductors fabricated on silicon wafers is investigated as an alternative that improves conversion efficiency while achieving higher inductance per area density.
Abstract: Intel's microprocessors are powered by high-frequency fully-integrated switching regulators implemented on die. Current products use non-magnetic inductors designed in the package substrate. This article investigates the use of magnetic thin film inductors fabricated on silicon wafers as an alternative that improves conversion efficiency while achieving higher inductance per area density. This article builds on the earlier work done on thin film inductors at Intel, and explores the feasibility of using them in a high volume product. A number of different design variations are studied to look at tradeoffs between efficiency, saturation characteristics, transient response, and voltage ripple. This is accomplished through a combination of passive measurements using a vector network analyzer (VNA) and active measurements on a fully functioning integrated voltage regulator system.