Voltage Loop Research Articles

Correction of crosstalk effect in the Low Energy RHIC electron Cooler Booster Cavity

The Low Energy Relativistic Heavy Ion Collider (RHIC) electron Cooler (LEReC) is designed to deliver a 1.6 MeV to 2.6 MeV electron beam, with rms dp/p less than 5e-4. The superconducting radiofrequency (SRF) Booster Cavity is the major accelerating component in LEReC. It is a 0.4 cell cavity operating at 2 K, providing a maximum energy gain of 2.2 MeV. It is modified from an experimental Energy Recovery Linac (ERL) photocathode gun, and thus has fundamental power couplers (FPCs), pickup (PU) couplers (field probes) and HOM coupler close to each other on the same side of the cavity. Direct capacitive coupling between the FPC and PU, called the crosstalk effect, combined with microphonic detuning, can induce closed loop voltage fluctuations that exceed the total energy spread requirement of LEReC. The crosstalk effect in this cavity is modelled, simulated, and measured, and a correction method is proposed and demonstrated to suppress the voltage fluctuation so that energy spread requirement can be met.

Studies of EC pre-ionization in DIII-D to support development of ITER plasma initiation

New experiments have been conducted at DIII-D to improve the physics understanding of plasma initiation assisted by electron cyclotron (EC) wave injection, allowing better extrapolation to ITER. This has been achieved by applying an EC pulse prior to start of the inductive plasma initiation (i.e. the generation of a loop voltage). A pre-plasma was formed during the EC pulse that was characterized in terms of the maximum density and temperature. Parametric scans were performed to study the influence of the EC injected power, EC injection angle, and pre-fill gas pressure on the pre-plasma creation process. These experiments showed that pre-ionized plasma of good quality can have a significant effect on the subsequent V loop induced plasma initiation process, i.e. a high density pre-plasma, increases the plasma current rise and speed at which ionization is achieved when the V loop is applied. A good quality pre-plasma is one that achieved a significant degree of ionization, mainly obtained by providing sufficient ECH power in DIII-D of the order of 1 MW. It was found that a minimum EC power of 0.5 MW was required in DIII-D to create ionization, and this would scale to a minimum power of roughly 6.5 MW for ITER.

Passivity‐based control for a DC/DC high‐gain transformerless boost converter

AbstractIn this work, an adaptive passivity‐based controller for a DC‐DC high‐gain transformerlessdouble‐inductor boost converter is fully detailed. The proposed current‐mode control scheme results in two feedback loops, a current controller for tracking the inductor current considering damping injection and energy shaping, and a voltage loop composed by a proportional‐integral action to guarantee output voltage regulation. Furthermore, a parametric uncertainty estimator using immersion‐invariance approach is designed to improve the robustness of the current loop. As a result, a multi‐loop adaptive nonlinear energy‐based controller, which ensures regional asymptotic stability via Lyapunov analysis is accomplished. In addition, considering practical conditions, real‐time numerical simulations, using a 1 kW case‐study converter, are carried out in order to assess the effectiveness of the proposed control scheme. Results for output voltage regulation, current tracking, and parametric uncertainty estimation under input voltage and load step changes are shown.

Current drive experiments in SST1 tokamak with lower hybrid waves

The steadystate superconducting tokamak (SST1) is aimed to demonstrate long pulse plasma discharges employing non-inductive current drive by means of lower hybrid current drive (LHCD) system. The major and minor radius of the machine is 1.1 m and 0.2 m, respectively. The LHCD system for SST1 comprises of klystrons, each rated for 0.5 MW-CW rf power at a frequency of 3.7 GHz. The grill antenna comprises of two rows, each row accommodating 32 waveguide elements. Electron cyclotron resonance breakdown assisted Ohmic plasma is formed in SST1 to overcome the issues associated with low loop voltage start-ups. With recent modifications in the poloidal coils configuration, even with narrow EC pulse (∼50 ms), good repeatable and consistent Ohmic plasmas could be produced which helped in carrying out LHCD current drive experiments on SST1. These experiments demonstrated both fully as well as partially driven non-inductive plasma current in SST1 tokamak. Discharges with zero loop voltages were obtained. The interaction of lower hybrid waves with plasma and generation of suprathermal electrons could be established using energy spectra measured by CdTe detectors. Various other signatures like drop in loop voltages, negative loop voltages, spikes in hard x-rays and increase in second harmonic ECE signal, further confirmed the current drive by LHW’s. The beneficial effect of LHW’s in suppressing hard x-rays was also demonstrated in these experiments. The longest discharge of ∼650 ms could be obtained in SST1 with the help of LHW’s. In this paper, the experimental results obtained with LHCD experiments on SST1 is reported and discussed in more details.

Improvement of the Control of a Grid Connected Photovoltaic System Based on Synergetic and Sliding Mode Controllers Using a Reinforcement Learning Deep Deterministic Policy Gradient Agent

This article presents the control of a grid connected PV (GC-PV) array system, starting from a benchmark. The control structure used in this article was a cascade-type structure, in which PI or synergetic (SYN) controllers were used for the inner control loop of id and iq currents and PI or sliding mode control (SMC) controllers were used for the outer control loop of the udc voltage from the DC intermediate circuit. This paper presents the mathematical model of the PV array together with the main component blocks: simulated inputs for the PV array; the PV array itself; the MPPT algorithm; the DC-DC boost converter; the voltage and current measurements for the DC intermediate circuit; the load and connection to power grid; the DC-AC converter; and the power grid. It also presents the stages of building and training the reinforcement learning (RL) agent. To improve the performance of the control system for the GC-PV array system without using controllers with a more complicated mathematical description, the advantages provided by the RL agent on process controls could also be used. This technique does not require exact knowledge of the mathematical model of the controlled system or the type of uncertainties. The improvement in the control system performance for the GC-PV array system, both when using simple PI-type controllers or complex SMC- and SYN-type controllers, was achieved using an RL agent based on the Deep Deterministic Policy Gradient (DDPG). The variant of DDPG used in this study was the Twin-Delayed (TD3). The improvement in performance of the control system were obtained by using the correction command signals provided by the trained RL agent, which were added to the command signals ud, uq and idref. The parametric robustness of the proposed control system based on SMC and SYN controllers for the GC-PV array system was proven in the case of a variation of 30% caused by the three-phase load. Moreover, the results of the numerical simulations are shown comparatively and the validation of the synthesis of the proposed control system was obtained. This was achieved by comparing the proposed system with a software benchmark for the control of a GC-PV array system performed in MATLAB Simulink. The numerical simulations proved the superiority of the performance of control systems that use the RL-TD3 agent.

Improved weighted average current control of LCL grid‐connected inverter and analysis of its order reduction characteristics

LCL grid-connected inverter is good at suppressing the high frequency current, but the inherent resonance frequency of the filter will lead to the resonance peak. Therefore, the active damping is commonly used to suppress the resonance effect. Since the weighted average current control can provide better bandwidth for the system with high frequency and has the characteristics of system reduction, it is often used to replace the traditional dual-loop current control in the application of LCL grid-connected inverter. However, the reduction of current resonance peak at the grid side by the weighted average current control is limited, so it is necessary to combine the grid voltage and capacitor current feedback loop to achieve the ideal results. In weak grid, the newly added feedback path would easily lead to the loss of system reduction, which results in the existence of transient variables in the transfer function affecting the stability of the control strategy. To solve this technical problem, this paper addresses a new control method of LCL grid-connected inverter based on weighted average current control. By adding a capacitor current feedback path, pole-zero cancellation of the control system is realised as to reduce the systematic order and improve the robustness of the controller under the time-varying weak grid.

Equivalent SM Controller for Load-Sharing and Dynamic Performance in a DC Microgrid Application

Load-sharing and voltage regulation are key challenges in low voltage dc microgrid systems. Droop-based decentralized control methods are used to control dc grids which cannot achieve these challenges simultaneously due to unequal voltages and load power variations. Centralized control schemes can achieve these challenges using high bandwidth communication. However, the failure of a single central controller can degrade performance and reliability. In addition, cascaded proportional-integral (PI) type controllers are used to control the voltage and current loop of each power electronic converter. These controllers suffer stability and show slower dynamic responses. Furthermore, control parameters cannot be optimized for different operating conditions. To address these challenges, a distributive control method using an equivalent sliding mode (SM) controller utilizing low bandwidth communication is proposed in this paper. The distributive method improves reliability and achieves load sharing and voltage regulation simultaneously. Furthermore, in SM, both voltage and current loop operate in the parallel configuration which improves the dynamic response and shows stability in all operating conditions. To analyze, a system model is developed, and existence and stability conditions are verified. Detailed simulations are carried out to show the steady-state and transient performance. The presented results show the effectiveness of the proposed scheme.

The concept of direct adaptive control for improving voltage and frequency regulation loops in several power system applications

This article presents the idea of direct adaptive control for several power system applications such as the Egyptian power system (EPS), a three-zone interconnected microgrid (MG), and a single machine connected to the grid (SMIB). The main concept of the proposed adaptive method is built on the tuning of the controller gains using Harris hawks optimizer (HHO). In order to maintain the frequency and voltage at their nominal values, a modified virtual rotor (virtual inertia + virtual damping) is investigated as a tertiary control loop within the proposed EPS and the 3-area MG system. For SMIB application, a secondary automatic voltage regulator (AVR) has been added to the primary AVR within the excitation system to offer more adequate damping characteristics for the synchronous generator of the studied system. Where the proportional-integral-derivative power system stabilizer (PID-PSS) is connected to the excitation system for a single machine tied to the grid to significantly mitigate low-frequency oscillations due to various expected faults and undesirable operating conditions. The proposed direct adaptive control strategy has been used to tune the integral controller of the secondary AVR and PID for SMIB application, and also to adjust the virtual rotor in the EPS and the 3-area MG applications. The operative performance of the introduced adaptive secondary AVR is assessed against the conventional system (no PSS), Lead-Lag PSS, and PSS type 2 based PSO and WECC standard under the effect of a 3-φ short-circuit fault subjected at the grid bus considering solar photovoltaic (PV) farm-based grid. Moreover, the EPS system and 3-area MG are evaluated under the effect of load change conditions and partial injection of PV and random loads. The final findings prove that the direct adaptive concept can provide robust performance and effectively maintain the dynamic stability of the main grid against fluctuations.

A switched quasi Z-source three-port (SqZSTP) DC-DC converter for a photovoltaic power generation system

In this paper, a modified wide-input switched quasi Z-source three-port (SqZSTP) DC-DC converter is proposed to interface a photovoltaic inverter with a distributed power generation system. The proposed SqZSTP DC-DC converter constructed with a quasi Z-source impedance network and a three-winding high-frequency transformer offers high voltage gain over a wide input voltage range. In the proposed topology, the input port is divided into two ports, to reduce the power rating and voltage stress across each component. The design and operating principles of the SqZSTP DC-DC converter are presented. The steady state and dynamic performance of the proposed SqZSTP DC-DC converter are compared to other converters that have an impedance network in front. The fuzzy logic controller used in the voltage loop avoids variation in the output voltage when a wide variation in the input voltage happens. In order to test the proposed topology, a scaled-down model with a voltage and power rating of 400 V/1400 W was developed. AT conversion efficiency of 94.5% is achieved.

Low-Frequency Oscillation Analysis in Train-Traction Power Supply System Using an SISO Voltage Loop Model

Low-frequency oscillation (LFO) in the train-grid coupling system severely endangers the stability and safety of railway operation. It is well known that this phenomenon is caused by impedance mismatch among the trains and the traction power supply system (TPSS). A novel voltage loop model of the single-phase pulsewidth modulation rectifier is proposed in this article. Unlike the commonly adopted multi-input multi-output (MIMO) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$d$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> impedance model in the literature, this is a single-input single-output (SISO) model that enjoys some advantages, such as easier calculation of the system poles and quantitative analysis of the stability margin. The most attractive character of this model in comparison to the MIMO one is perhaps the decoupling of the controller and the voltage loop. This paves the way toward the analytical design of the dc-link voltage controller (DVC), whereas the impedance model is mainly useful for analysis. Furthermore, the maximum amount of trains allowed for keeping stability is derived from the steady-state equation. Robust stability margin (RSM) and sensitivity analysis are adopted to quantitatively investigate the influence of the control parameters and the circuit element parameters. LFO is guaranteed to be eliminated permanently by adjusting the controller parameters.

An Improved Voltage and Frequency Control for Islanded Microgrid Using BPF Based Droop Control and Optimal Third Harmonic Injection PWM Scheme

Droop control is commonly used for primary control of island microgrids at the expense of voltage deviations. Furthermore, voltage and frequency restoration can be achieved using droop control along with the communication line. However, system complexity increases and reliability decreases due to the communication delay and data loss. Also, overmodulated voltage source converters (VSCs) degrade the ac output in a converter-dominated islanded microgrid. In this article, an improved technique is proposed to control voltage and frequency for an islanded microgrid. The band-pass filter-based droop control (an equivalent secondary control without a communication line) is developed to control distributed inverters to enhance voltage and frequency regulation by reducing response time, overshoot, and steady-state error. Furthermore, a modified proportional integral derivative (MPID) controller is adopted for inner voltage and current loop control to handle the system response fluctuation subject to perturbation and eliminate further voltage quality deterioration. For optimal control action of MPID controller, the controller parameters are tuned using dynamic weighted salp swarm algorithm and validated by both bode plot and step response. Furthermore, an optimal third harmonic injection-sine pulsewidth modulation technique is proposed to reduce the harmonic generation for the entire operation region of the VSC. The proposed control technique is simulated in MATLAB Simulink, and its performance is compared with a state-of-the-art method. Also, the proposed control technique is validated on the OPAL-RT real-time simulator test bench. Investigation revealed that the proposed technique improved the voltage and frequency regulation and effectively minimized overshoots and steady-state errors of the system.

Synchronous Generator Imitation Control and Dynamic Power Sharing for Distributed Power Generation Systems

In this paper, a control method called synchronous generator imitation control (SGIC) as well as a dynamic power sharing for distributed power generation systems (DPGSs) are presented. In order to imitate the behavior of a synchronous generator (SG), the SGIC method for the voltage source converter (VSC) station is proposed. The SGIC includes three loops, namely active power and frequency loop (Pf loop), reactive power and voltage loop (QU loop) as well as inner current loop. The Pf loop is used to emulate the swing equation of the SG. The exciter of the SG is mimicked by the QU loop. The inner current loop is developed for fast current and voltage regulations as well as current limiting. The system stability performances are analyzed through small-signal model, and the effectiveness of the proposed control is validated by PSCAD/EMTDC simulations. The results show that the Pf loop of the VSC emulates the motion equation of the SG rotor very well, which makes the VSC station to have inertia just as a SG; the VSC station can maintain a stable output voltage and regulate the reactive power at the same time; through the dynamic power sharing, precise power control, frequency offset elimination and system stability improvement are achieved; the system has the merits of fault ride-through capability as well as good dynamic performance.

Damping of Subsynchronous Resonance in Utility DFIG-Based Wind Farms Using Wide-Area Fuzzy Control Approach

This paper presents a novel fuzzy control scheme for damping the subsynchronous resonance (SSR) according to the wide-area measurement system (WAMS) in power systems including doubly fed induction generator (DFIG)-based wind farms connected to series capacitive compensated transmission networks. The SSR damping is attained by adding the fuzzy controller as a supplementary signal at the stator voltage loop of the grid-side converter (GSC) of DFIG wind farms. Additionally, time delays due to communication signals are important when using WAMSs. If the time delays are ignored, it causes system instability. In this paper, the time delays are modeled with a separate fuzzy input to the controller. The new fuzzy control approach is executed by using the angular velocity of synchronous generators (w) and its variation in the angular velocity (dw/dt). The effectiveness and success of the WAMS-based fuzzy controller is demonstrated by comparison with the particle swarm optimization (PSO) and imperialist competitive algorithm (ICA) optimization methods. The efficacy and validity of the planned auxiliary damping control are verified on a modified version of the IEEE second benchmark model including DFIG-based wind farms via time simulations using the MATLAB/Simulink toolbox.

Modelling And Analysis Of Pvsc Type Buck Buck-Boost Dc-Dc Converter

In the era of modern industrial development, power electronics equipment has been developed aggressively and brought dc system again in power utilization to use clean energy resources like solar array, fuel cell, wind generator, etc. Since the past decade, power electronics equipment has become very popular; hence, the switch-mode converter requirement is increasing rapidly day by day in applications like communication power supply, space crafts, hybrid electric vehicles, micro-grid and nano-grids. Among the various available configurations of converters, Multi-Input DC/DC converters became more and more popular in power electronics field, especially, for provide interface of various renewable energy sources and deliver regulated power to several loads. In this article, a PVSC type Buck Buck-Boost Dual-Input DC- DC Converter (DIDC) is designed and modelled for DC grid application. The proposed converter is driven with two renewable energy sources PV cell and a battery having different amplitudes which can able to deliver the power from source to load individually or simultaneously. DIDC tropology is simply configured with two passive elements L, C, diodes D1 D2 and switches S1 , S2. The Dual-Input DC-DC Converter suitability is validated by carrying out simulations in different modes of operation. The de-centralized PID controller is designed for voltage and current loop controller to ensure the DC output voltage of 48 V, load current of 4.8 A and power of 230W. The Stability of the closed-loop converter is also verified under all possible source and load disturbance conditions. The simulations and analysis of the proposed converter are carried out using MATLAB and PSIM software.

Dynamo chiral plasma instabilities from charges and oscillations driven by torsion fluctuations

Recently, Barrow et al. showed that chaotic dynamical systems may be obtained from small fluctuations of torsion in cosmological plasmas. Following this idea our goal in this paper is to show analytically that torsion fluctuations in primordial plasmas induce chiral fluctuations, magnetic field fluctuations, dynamo plasma instabilities, as well as rapid oscillations in the chiral plasma. These phenomena are important in plasma relaxation to allow for a plasma dynamo instability to induce a lower electric voltage in plasmas. This phenomenon is induced in Minkowskian plasma physics, but to our knowledge it is proved for the first time in Einstein–Cartan sort of cosmology. In cosmological models where torsion gravity and electromagnetic fields are non-minimally coupled, dynamo instability is obtained when conductivity fluctuations are driven by torsion. Moreover, symmetry breaking of plasmas is shown here to be obtained from conductivity torsion fluctuations, which serves to bypass Zeldovich anti-dynamo theorem, inducing a dynamo onset, as shown recently in domain planar walls [L. Garcia de Andrade, Einstein–Cartan spin-polarised nucleons in domain wall dynamos, Ann Phys. (N.Y.) 432 (2021) 168558.]. Moreover, chiral charge fluctuations are shown to be induced by torsion fluctuations. It is shown that chiral charges may vanish, whereas the effective chiral charges may be driven by torsional fluctuations. It is also shown that dynamo electric field induces a magnetic helicity which oscillates and dynamo action is shown to dominate oscillations. This agrees with the results obtained from loop voltage. Chiral effective charges’ fluctuations are derived to be proportional to the product of anisotropic conductivity and magnetic field fluctuations.

Modified zeta inverter intended for single-phase grid-tied photovoltaic system

A novel integrated converter structure intended for a single-phase grid-tied photovoltaic (PV) system is proposed in this paper. The proposed topology, named Modified Zeta Inverter (MZI), is deployed using two modified Zeta converters operating in discontinuous conduction mode. The main advantage of the MZI is its capability to step-up the input voltage while injects into the single-phase utility grid the energy produced from photovoltaic arrangements. Besides low total harmonic distortion in the grid-injected current, the proposed MZI topology was conceived to replace the conventional two-stage grid-tied system. A comprehensive study involving both static and dynamic analyses is presented. Furthermore, small-signal modeling is developed to give subsidies for designing the controllers' gains adopted in the voltage and current control loops. After a proper system sizing, it was developed a prototype setup with 432 W. Simulation and experimental results are presented to evaluate and demonstrate the feasibility of the proposed system.

Effect of Thermal Conductivity of Substrate on the Giant Persistent Photoconductivity of Vanadium Dioxide Device

AbstractThe substrate effect on giant persistent photoconductivity (GPPC) of VO2devices fabricated on the substrates of corning glass, Al2O3(0001), and TiO2(001) is investigated. Under the applied voltage within the hysteresis loop of voltage–current curve of the VO2device, the GPPC is achieved by a short single pulse laser at laser intensity of 8.9×106W m−2. The minimum laser pulse width (Wmin) to trigger GPPC in VO2devices is found to be as small as 80 µs in the VO2device fabricated on corning glass substrate. The magnitudes ofWminfor GPPC increase in the order of corning glass, TiO2, and Al2O3substrates. The variation of theWminon each substrate is understood as the dissimilarity of thermal conductivity of each substrate. The minimum time required to induce GPPC (the incubation time) is estimated using 1D thermal transport model, which shows good qualitative agreement with experimental results.

HfO2-ZrO2 Superlattice Ferroelectric Capacitor With Improved Endurance Performance and Higher Fatigue Recovery Capability

HfO₂-ZrO₂ superlattice (SL) ferroelectric (FE) capacitor is demonstrated to have improved endurance performance and higher fatigue recovery capability compared to the HfZrO_<i>x</i> (HZO) device. During the cycling of polarization (<inline-formula> <tex-math notation="LaTeX">${P}$ </tex-math></inline-formula>) <i>vs.</i> voltage (<inline-formula> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula>) loops, the SL metal-FE-metal (MFM) capacitor exhibits the higher <inline-formula> <tex-math notation="LaTeX">${P}$ </tex-math></inline-formula> and the lower leakage current over the HZO device indicating the lower defect density in SL. The SL capacitor achieves an endurance of <inline-formula> <tex-math notation="LaTeX">${5}\times {10} ^{{12}}$ </tex-math></inline-formula> cycles, which is three orders of magnitude higher than the HZO device. The <inline-formula> <tex-math notation="LaTeX">${P}$ </tex-math></inline-formula> fatigue of the SL capacitor can be fully recovered through a &#x007E;30 s break, and that of HZO is only partially recovered utilizing the higher field cycling. This is because the trapping/detrapping process significantly decreases in HfO₂-ZrO₂ SL over HZO capacitor by the reduced defect density. These results prove that the HfO₂-ZrO₂ SL is a promising technology for endurance unlimited FE random access memory.

A 0.8-V, 2.55-GHz, 2.62-mW Charge-Pump PLL With High Spectrum Purity

This article presents a low supply voltage and low-power charge-pump phase-locked loop (CPPLL) with phase noise (PN) improvement and reference spur reduction techniques. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$V_{\mathrm {ref}}$ </tex-math></inline-formula> adaptive adjustment mechanism is analyzed in the class-C voltage-controlled oscillator (VCO) with dual-mixed loops, which eliminates the PN’s sensitivity to temperature and process. Moreover, based on resistance-based accurate current replication, the low-power and low-current mismatch charge-pump (CP) circuit structure is proposed to reduce the reference spur of the PLL. In addition, by using the dynamic current compensation scheme, the power consumption of the CP is greatly reduced. The proposed PLL is fabricated in a 0.18- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> RF CMOS process with an area of 1.07 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> 1.07 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The measurement results show that the proposed PLL achieves a 2.24–2.85-GHz frequency tuning range and a PN of −123.97 dBc/Hz at 1-MHz offset from a 2.55-GHz carrier. The measured reference spur is −89.4 dBc at 40-MHz offset frequency and the total power consumption is 2.62 mW at the 0.8-V power supply voltage.

Improvement of Steady State Performance of Voltage Control in Switched Reluctance Generator: Experimental Validation

This paper presents a voltage control approach to a Switched Reluctance Generator (SRG) using a Proportional Integral (PI) controller. The principle of operation is described and the considerations in the design of controller are discussed. A current loop transfer function of an SRG with power converter has been systematically derived in order to obtain a small-signal model for the generator. The generated voltage is controlled by manipulation of the setpoint of the current control of the generator. The entire voltage loop controller and current control have been simulated and tested with a 250 W SRG prototype. The control law of the control system was implemented on a digital signal processor (TMS320F28379D). To verify the feasibility of the proposed voltage control, the performances are evaluated by numerical simulations and experimental tests with an 8/6 SRG for different rotational speeds and resistive loads. Experimental results demonstrate that the DC output voltage from SRG can be controlled well using a simple linear controller.