Permanent Magnet Brushless DC Generator Research Articles

Wind–PV–Battery Hybrid Off-Grid System: Control Design and Real-Time Testing

The paper presents the design and implementation of decentralized control for a PV–wind–battery hybrid off-grid system with limited power electronics devices and sensors. To perform well without using any maximum power point tracking (MPPT) technique from the wind turbine (WT) based on a permanent-magnet brushless DC generator (PMBLDCG) and solar panels (PVs) and balance the power in the system, a cascade control structure strategy based on a linear active disturbance rejection controller (LADRC) is developed for the two-switch DC-DC buck-boost converter. Moreover, to ensure an uninterruptible power supply to the connected loads with a constant voltage and frequency, a cascade d-q control structure based on LADRC is developed for the interfacing single-phase inverter. Furthermore, the modeling and controller parameters design are presented. The performance under all operation conditions of the hybrid off-grid configuration and its decentralized control is validated by simulation using MATLAB/Simulink and in real-time using a small-scale hardware prototype.

Grid Sychronization of Wind Based Microgrid

Abstract: This paper presents the methods for synchronization of a wind based micro grid with main grid. The wind power is generated using the permanent magnet brushless DC generator (PMBLDCG) and the MPPT (Maximum Power Point Tracking) is executed with P&O (Perturb & Observe) approach to extract the maximum power from the wind generation. This power is fed to the AC load using a voltage source inverter (VSI) through the battery bank (BSS) at DC link. The control algorithm operates in standalone mode and grid connected mode. It can switch between islanded and grid connected modes seamlessly according to the wind conditions. In standalone mode, this wind power is fed to the load through a VSI, during low wind conditions; the battery discharges itself to fulfill the load demand. After that, the grid is connected to give power to the load during low wind conditions, and for this, control algorithm operates in grid connected mode. Therefore, the control algorithm switches from voltage control to current control mode to provide smooth synchronization and vice versa at de-synchronization. A MATLAB Simulink model is developed to simulate the system performance during wind variations and load, and during synchronization and de-synchronization.

Sliding Mode Control of Hybrid Renewable Energy System

This paperpresents an ANFIS based adaptive sliding mode control (ASMC) of a standalone single phase microgrid system. The proposed microgrid system integrates a micro-hydro turbine driven single-phase two winding self-excited induction generator (SEIG) with a wind driven permanent magnet brushless DC (PMBLDC) generator, solar photo-voltaic (PV) array and a battery energy storage system (BESS). These renewable energy sources are integrated using a single-phase voltage source converter (VSC). The ASMC based control algorithm is used to estimate the reference source current which controls the single-phase VSC and regulates the voltage and frequency of the microgrid in addition to harmonics current mitigation. The adaptive sliding mode control with ANFIS is used to maintain the energy balance among wind, micro-hydro, solar PV power and BESS, which controls the frequency of standalone microgrid. Simulation results from MATLAB/SIMULINK of the proposed microgrid shows that the grid voltage and frequency are maintained constant while the system is following various changes in dynamic state such as sudden change in wind speed, changes in solar insolation level and changes in loads.

Voltage Regulation of Hydro Standalone 1-Φ Micro Grid using Fuzzy Logic Based Adaptive Sliding Mode Control Algorithm

This paper presents an adaptive sliding mode control (ASMC) of an improved power quality standalone single phase microgrid system. The proposed microgrid system integrates a governor-less micro-hydro turbine driven single- phase two winding self-excited induction generator (SEIG) with a wind driven permanent magnet brushless DC (PMBLDC) generator, solar photo-voltaic (PV) array and a battery energy storage system (BESS). These renewable energy sources are integrated using only one single-phase voltage source converter (VSC). The ASMC based control algorithm is used to estimate the reference source current which controls the single-phase VSC and regulates the voltage and frequency of the microgrid in addition to harmonics current mitigation. The proposed ASMC estimates the reference real and reactive powers of the system, which is adaptive to the fluctuating loads. The sliding mode control is used to estimate the reference real power of the system to maintain the energy balance among wind, micro-hydro, solar PV power and BESS, which controls the frequency of standalone microgrid. The proposed microgrid is implemented in real time using a DSP (Digital Signal Processor) controller. Test results of proposed microgrid shows that the grid voltage and frequency are maintained constant while the system is following a sudden change in loads and under intermittent penetration of wind and solar energy sources.

Adaptive Neural Fuzzy Inference System Based Adaptive Sliding Mode Control of a Standalone Single-Phase Microgrid

This paperpresents an ANFIS based adaptive sliding mode control (ASMC) of a standalone single phase microgrid system. The proposed microgrid system integrates a micro-hydro turbine driven single-phase two winding self-excited induction generator (SEIG) with a wind driven permanent magnet brushless DC (PMBLDC) generator, solar photo-voltaic (PV) array and a battery energy storage system (BESS). These renewable energy sources are integrated using a single-phase voltage source converter (VSC). The ASMC based control algorithm is used to estimate the reference source current which controls the single-phase VSC and regulates the voltage and frequency of the microgrid in addition to harmonics current mitigation. The adaptive sliding mode control with ANFIS is used to maintain the energy balance among wind, micro-hydro, solar PV power and BESS, which controls the frequency of standalone microgrid. Simulation results from MATLAB/SIMULINK of the proposed microgrid shows that the grid voltage and frequency are maintained constant while the system is following various changes in dynamic state such as sudden change in wind speed, changes in solar insolation level and changes in loads

Robust Control Strategies for SyRG-PV and Wind-Based Islanded Microgrid

The nonlinearity in the consumption does not maintain steady voltage or frequency; therefore, in this article, a circular limited cycle oscillator frequency locked loop with prefilter (CLO-FLL-WPF) based control for voltage source converter control is used to achieve voltage and frequency regulation in an islanded microgrid (MG). This control is implemented to compensate local load reactive power, harmonic currents, and load unbalance. Besides, the active power of local loads is shared among the multiple energy sources. The CLO-FLL-WPF control technique performance is validated experimentally and through simulations by comparing it with the existing control algorithm in a MG. This MG is a combination of the solar photovoltaic array, pico-hydro turbine-driven synchronous reluctance generator, permanent magnet brushless dc generator based wind energy conversion, and battery storage. In traditional battery control, a proportional-integral control approach is used, which can cause a stability problem. Thereby, in this article, the bidirectional dc–dc converter control method is used, which provides improved stability and makes the controller design straightforward. Test results validate the effectiveness of the control algorithm under different dynamic and steady-state conditions.

Comprehensive Controller Implementation for Wind-PV-Diesel Based Standalone Microgrid

In this paper, a comprehensive controller of a standalone microgrid is implemented, which has three dispersed generation units based on a wind, solar photovoltaic (PV) array, and a diesel generator (DG). The power ratio variable step perturb and observe method is applied to achieve maximum power point tracking of a solar PV array and a variable speed wind turbine coupled a permanent magnet brushless dc generator without rotor/wind speed sensors. Moreover, to ensure perfect synchronization of a DG to the point of common coupling (PCC), a control algorithm is developed, which is based on in-phase and quadrature units. An active power control based on proportional–integral controller with anti-windup, is used for voltage and frequency regulation. The LCL filter based on virtual resistor, is used for power quality improvement at PCC. Simulation and test results are presented for the validation of the proposed system using a prototype of 2 kW in the laboratory.

Adaptive Sliding Mode Control of Standalone Single-Phase Microgrid Using Hydro, Wind, and Solar PV Array-Based Generation

This paper presents an adaptive sliding mode control (ASMC) of an improved power quality standalone single phase microgrid system. The proposed microgrid system integrates a governor-less micro-hydro turbine driven single-phase two winding self-excited induction generator with a wind driven permanent magnet brushless dc generator, solar photo-voltaic (PV) array and a battery energy storage system. These renewable energy sources are integrated using only one single-phase voltage source converter (VSC). The ASMC-based control algorithm is used to estimate the reference source current which controls the single-phase VSC and regulates the voltage and frequency of the microgrid in addition to harmonics current mitigation. The proposed ASMC estimates the reference real and reactive powers of the system, which is adaptive to the fluctuating loads. The sliding mode control is used to estimate the reference real power of the system to maintain the energy balance among wind, micro-hydro, solar PV power, and BESS, which controls the frequency of standalone microgrid. The proposed microgrid is implemented in real time using a digital signal processor controller. Test results of proposed microgrid shows that the grid voltage and frequency are maintained constant while the system is following a sudden change in loads and under intermittent penetration of wind and solar energy sources.

PMBLDCG based stand-alone wind energy conversion system for small scale applications

This paper deals with a permanent magnet brushless DC generator (PMBLDCG) based stand-alone wind energy conversion system (WECS) for small scale power generation. A buck-boost DC-DC converter is used for controlling the PMBLDCG speed to achieve optimum energy output from the wind turbine without sensing wind speeds. An uncontrolled diode bridge rectifier is used in between PMBLDCG terminals and input of a buck-boost converter. The buck boost converter feeds the generated power to a battery energy storage system (BESS) and consumer loads. A single-phase voltage source inverter (VSI) is used at the DC bus to feed regulated voltage and frequency AC supply to consumer loads. The performance of the voltage and frequency controller is demonstrated as a maximum power point tracker, a load leveler, an active filter along with a voltage and frequency controller.Keywords: Permanent Magnet Brushless DC Generator, Buck Boost Converter, Battery, Wind Power, Maximum Power Point Tracking

Back-Propagation Algorithm-Based Controller for Autonomous Wind–DG Microgrid

This paper deals with a wind–diesel generator hybrid configuration of the microgrid using a voltage source converter (VSC) as a voltage and frequency (VF) controller. The wind power generated by permanent magnet brushless dc generator, and the maximum power is captured by a maximum power point technique using a boost converter with an incremental conductance approach. This power is supplied to the consumer loads and surplus power is stored into battery system (BS). BS is attached at dc link of VSC, which provides load leveling during less or no wind conditions. With such combination of energy resources, a reduced rating, diesel engine-driven squirrel cage induction generator feeds loads, and VSC at point of common coupling (PCC) supports the system when the wind generation is unable to meet out the load demand. Back-propagation feed-forward control algorithm is used for VF control of VSC. This controller provides harmonics elimination, load leveling, and reactive power compensation, and also regulates the voltage at PCC. This microgrid is modeled in MATLAB Sim power tools, and simulation results are produced to verify the appropriate working of both the converters and the overall system. A prototype of the microgrid is also developed to validate the design and model through test results. A comparative study of simulated and experimental work is given in detail.

Control of Wind-Diesel Microgrid Using Affine Projection-Like Algorithm

This paper deals with brushless generators-based isolated wind-diesel microgrid for rural areas. Here, a permanent magnet brushless dc generator (PMBLDCG) is used to convert renewable wind power into electrical energy. A diesel engine-driven generator based on the squirrel-cage induction generator (SCIG) and a battery storage system (BSS) with a voltage source converter (VSC) deliver power to feed necessary loads. BSS provides load leveling during load variations and wind fluctuations. For such microgrid, control schemes must be accurate and robust to overcome any discrepancy, and able to provide voltage and frequency regulation to the microgrid. Here, voltage and frequency control at the point of common coupling (PCC) is achieved with affine projection-like (APL) algorithm by proper switching of a VSC. This control algorithm is also able to provide reactive power compensation, load balancing, and harmonics suppression, and therefore provides sinusoidal voltage supply. Performance of the algorithm is demonstrated with wide range of test results of developed prototype of proposed microgrid.

Design and implementation of a low-cost maximization power conversion system for brushless DC generator

This paper presents a simple and low-cost method to capture maximum power throughput of permanent magnet brushless DC (BLDC) generator. Conventional methods of rectification are based on passive converters, and because the current waveform cannot be controlled as ideal waveform, a highly distorted current is drawn from brushless generator. It leads to lower power factor and reduces the efficiency and power per ampere capability. So, in this study an active six-witch power converter is employed and based on the phase back-EMF voltage, an optimum current waveform is generated. The phase currents are controlled inphase to phase voltages and their magnitudes are adjusted to regulate the DC-link voltage. Proposed control theory is verified by simulations for BLDC generator and permanent magnet synchronous generator (PMSG). Moreover, some experimental results are given to demonstrate the theoretical and simulation results.

Reduced converter topology for integrated wind and small‐hydro energy generation system

This study presents a robust and cost-effective microgrid topology for integrating two commonly available wind and small-hydro renewable energy sources. The proposed topology has two generators, one of them is self-excited squirrel cage induction generator driven by a small-hydro turbine and other one is permanent magnet brushless DC generator driven by a small-scale wind turbine. The proposed system is integrated using a voltage source converter and a boost converter which are maintaining voltage and frequency, mitigating power quality problems and performing mechanical sensorless maximum power point tracking, respectively. A battery bank is also used to balance the load and supply power mismatch and to ensure the supply for critical loads. The proposed control algorithm is tested and verified on a developed laboratory prototype of the system. Test results verify that voltage and frequency of the system are regulated and the power-quality-related issues are also resolved in this microgrid.

Modeling, simulation, and analysis of variable-speed constant frequency power conversion scheme with a permanent magnet brushless DC generator

A variable-speed, constant-frequency (VSCF) power-conversion scheme with a permanent magnet DC (PMDC) brushless generator is proposed. The scheme is completely modeled for steady state by integrating the characteristic equations of the generator, the diode rectifier bridge and the inverter, and the harmonic characteristics for steady-state performance computation. Commutation overlap effects are also included. Key performance characteristics are experimentally verified with a laboratory prototype. The excellent correlation between the predicted and experimental results confirms the validity of the model. For the purpose of filter design, harmonics of the rectified generator voltages are analytically derived. A recommendation for overcoming the low power factor on the utility side at low speeds using the forced-commutated converters is given. >