Generator Control Research Articles

Mitigation of severe false data injection attacks (FDIAs) in marine current turbine (MCT) type 4 synchronous generator renewable energy using promoted backstepping method

False data injection attack (FDIA) is kind of the most important and prevalent cyber attacks, influencing in power systems and renewable energy resources in microgrids (MGs). The destructive effects caused by FDIAs in the voltage components of synchronous generator with full converter in AC microgrid (ACMG) renewable energy production would seriously damage the DC link voltage, network frequency and also, the active power. The extracted voltage components in the d and q axes to control the grid side converter (GSC) as the main control section, are the important signals for power control process of the synchronous generator with wind or marine current turbine (MCT). In this regards and due to the nonlinear behavior caused by cyber attacks in the generator control process, the robust performance of modified nonlinear backstepping method would be an appropriate alternative, instead of the conventional linear control including PI controllers. Thus, a remedial action against various FDIAs caused in the voltage control commands of the GSC is proposed. Moreover, promotion of the backstepping control by combining with the switching terms, adopted from the higher order super twisting sliding mode control (HOSTSMC), the performance of the proposed method would be precisely robust. To verify the proposed method, severe FDIAs by injecting various constant values, periodic and also, noisy signals are our case studies which are simulated via MATLAB software in the weak grid connect and standalone operation modes.

An Improved Grid-connected Pre-Synchronization Method based on Virtual Synchronous Generator Control in Power Conversion System

Under the background of vigorously promoting the construction of new power system，the power conversion system(PCS) plays an important role to transfer high reliable electrical power quality to grid. However, the system is sensitive to the voltage deviation on both side of point of common coupling(PCC) when switching from off-grid mode to grid-connected mode directly, it leads to surge currents or even threaten system stability.In this paper, an improved grid-connected pre-synchronization method for smooth grid connection is proposed. The system adds a pre-synchronization module on the basis of virtual synchronous generator(VSG) control to synchronize the voltage between the PCS and the grid. In addition, a slope control unit is introduced to further avoid the potential surge current problem at the moment of grid connection. Finally, the experimental results of simulation is verified the effectiveness and feasibility of the proposed scheme.

Adaptive Inertial Control for Wind Turbine Generators in Fast Frequency Response Based on the Power Reduction Period Assessment

Adaptive Inertial Control for Wind Turbine Generators in Fast Frequency Response Based on the Power Reduction Period Assessment

Grid Forming Fast Frequency Response for PMSG-Based Wind Turbines

Electric power systems are undergoing a rapid transition from fuel-based generation using synchronous generators to renewable generation interfaced by power electronics. In this context, a key challenge is using renewable generation with limited controllability to contribute to power system stability. In this work, we investigate grid-forming control of permanent magnet synchronous generator (PMSG) wind turbines. The proposed control and curtailment strategy supports the entire spectrum of standard functions of grid-following (e.g. maximum power point tracking (MPPT) and grid-forming control (e.g., primary frequency control) without explicit mode switching. A detailed case study is used to compare the performance of the proposed control at operating points corresponding to MPPT and frequency control with standard grid-forming and grid-following controls. The results demonstrate that (i) the proposed energy balancing grid forming control is self-synchronizing in MPPT mode, (ii) the (limited) energy storage and controllability of wind turbines can be adequately utilized to provide grid support, and (ii) the proposed control exhibits good performance under variable wind speeds and does not result in a significant increase of wind turbine fatigue loads.

Voltage stabilization control for dual three-phase permanent magnet synchronous generator based on cascaded linear active disturbance rejection control

Voltage stabilization control for dual three-phase permanent magnet synchronous generator based on cascaded linear active disturbance rejection control

Peak Shaving Control for a Virtual Synchronous Generator in Island Grids

Peak Shaving Control for a Virtual Synchronous Generator in Island Grids

Feedback Control of Doubly-Fed Generator Connected to Current Source Converter

Feedback Control of Doubly-Fed Generator Connected to Current Source Converter

Efficiency Enhancement Using Fault-Tolerant Sliding Mode Control for the PMVG-Based WTS Under Actuator Faults

This study focuses on efficiency enhancement using fault-tolerant sliding mode control (SMC) for permanent magnet vernier generator (PMVG)-based wind turbine system (WTS) under actuator faults. To do this, the dynamical model of the WTS is constructed with the actuator fault model. Next, the optimum tip speed ratio-based SMC method is proposed to calculate the optimum speed reference of the maximum power point tracking controller that achieves the maximum power capture of the WTS. And then, to effectively track the optimum rotor speed under actuator faults, a disturbance attenuation-based sliding surface is proposed with a novel time-varying exponential reaching law. At the same time, the stability conditions of the SMC are also derived using the appropriate Lyapunov function. Finally, the resilient performance and superiority of the proposed control method are demonstrated through simulation for 5-kW PMVG-based and, 4.8-MW benchmark WTSs and its applicability is proven through an experimental prototype for the 5-kW PMVG-based WTS.

Real-time Neural Sliding Mode Linearization Control for a Doubly Fed Induction Generator under Disturbances

Abstract This paper presents an experimental implementation of a Neural Sliding Mode Linearization approach for the control of a double-fed induction generator connected to an infinite bus via transmission lines. The rotor windings are connected to the grid via a back-to-back converter, while the stator windings are directly coupled to the network. The chosen control scheme is applied to obtain the required stator power trajectories by controlling the rotor currents and to track the desired values of the DC-link output voltage and the grid power factor. This controller is based on a neural identifier trained online using an Extended Kalman Filter. Based on such identifier, an adequate model is obtained, which is used for synthesizing the required controllers. The proposed control scheme is experimentally verified on 1/4 HP DFIG prototype considering normal and abnormal grid conditions. In addition, maximum power extraction from a random wind profile is tested in the presence of different grid scenarios. Moreover, a comparison with conventional control schemes is performed. The obtained results illustrate the capability of the proposed control scheme to achieve active power, reactive power, and DC voltage desired trajectories tracking and to operate the wind power system even in the presence of parameter variation and grid disturbances, which helps to ensure the stability of the system and improve generated power quality.

Passive Control for Brushless Doubly-Fed Reluctance Generator under Unbalanced Grid Voltages

Passive Control for Brushless Doubly-Fed Reluctance Generator under Unbalanced Grid Voltages

Framework for Sensorless Control and Flying Start of a Permanent Magnet Generator Based on a Sliding Mode Observer

This paper deals with a sensorless control of permanent magnet generators (PMGs) including a method of flying start. Flying start involves synchronization between the voltages of the generator-side converter (GSC) and the PMG, as well as switching on the GSC. Without a proper flying start, inrush current and impact torque can cause undesirable side effects. In this paper, a framework for the sensorless control of the PMG based on a sliding mode observer (SMO) is proposed, which includes the flying start method. The flying start is performed during a discontinuous operation of the GSC. This method ensures the flying start and continuous operation of the PMG, with few adjustments required between the two modes. In addition, the self-commissioning method is used to determine the PMG parameters required to tune the SMO and current controllers, and to reduce the SMO estimation error. The new method is verified experimentally on a 5.5 kW PMG.

Transient Stability Enhancement Control for Virtual Synchronous Generator Controlled Isolated Power Grid

Transient Stability Enhancement Control for Virtual Synchronous Generator Controlled Isolated Power Grid

A Novel Adaptive Nonlinear Reaching Law for DC-link Voltage Control of DC-biased Vernier Reluctance Generator

A Novel Adaptive Nonlinear Reaching Law for DC-link Voltage Control of DC-biased Vernier Reluctance Generator

Stability Analysis and Enhanced Virtual Synchronous Control for Brushless Doubly-fed Induction Generator Based Wind Turbines

Stability Analysis and Enhanced Virtual Synchronous Control for Brushless Doubly-fed Induction Generator Based Wind Turbines

Grid-Forming Control of DFIG-based Wind Turbine Generator by Using Internal Voltage Vectors for Asymmetrical Fault Ride-Through

Grid-Forming Control of DFIG-based Wind Turbine Generator by Using Internal Voltage Vectors for Asymmetrical Fault Ride-Through

Synthesis, dynamic modeling, prototyping and control of a handheld rotational inertia generator.

This paper explores the design and experimental validation of a three-degree-of-freedom variable inertia generator. An inertia generator is a handheld haptic device that renders a prescribed inertia. In the mechanism proposed in this paper, three-dimensional torque feedback is achieved by accelerating three pairs of flywheels mounted on orthogonal axes. While the primary objective of this work is to design an inertia generator, this study also includes developing other functionalities for the device that exploit its torque generation capabilities. These include the ability to generate a predefined torque profile and to simulate a viscous environment through damping, which are both utilized to assess the device's performance. The device proved to accurately render the necessary torques for every functionality while presenting some limitations for damping and rendering an inertia smaller than the device's inherent inertia.

Designing a Fertilizing Robot Application Considering Energy Efficiency

Abstract Electrically driven agricultural robots encounter accelerated battery depletion compared to vehicles operating on asphalt due to heightened rolling and traction resistance necessitating increased energy consumption. This issue becomes pronounced in regions devoid of access to the electrical grid, precluding the possibility of recharging electrically driven agricultural robots and consequently leading to interruptions in their uninterrupted functionality. To address this challenge, the agrorobotics working group at the Estonian University of Life Sciences devised a novel solution: a combined energy production station leveraging biogas, hydrogen, and solar energy. This station was integrated with a prototype autonomous fertilizing robot tailored for blueberry plantations to conduct precision fertilization on depleted milled peat fields. Distinctive features of the station encompass an automated battery exchange system and an electric generator equipped with a membrane motor. These components, in conjunction with a solar energy and electric generator control system, alongside a battery charger, are affixed onto a mobile platform. The primary objective of this study was to ascertain the energy requisites of an autonomous fertilizing robot during field traversal and while executing technological operations. To achieve this aim, the mechanical power and energy necessary for the operation of the robot fertilizer spreader were initially quantified. Subsequently, an accumulator possessing suitable power and capacity for the operation of the robot fertilizer spreader was chosen. The article further delineates the determination of the travel distance achievable by the robot on a single charge of the selected accumulator, in addition to evaluating the traction power efficiency and specific power.

A Bidirectional Grid-Friendly Charger Design for Electric Vehicle Operated under Pulse-Current Heating and Variable-Current Charging

Low-temperature preheating, fast charging, and vehicle-to-grid (V2G) capabilities are important factors for the further development of electric vehicles (EVs). However, for conventional two-stage chargers, the EV charging/discharging instructions and grid instructions cannot be addressed simultaneously for specific requirements, pulse heating and variable-current charging can cause high-frequency power fluctuations at the grid side. Therefore, it is necessary to design a bidirectional grid-friendly charger for EVs operated under pulse-current heating and variable-current charging. The DC bus, which serves as the medium connecting the bidirectional DC–DC and bidirectional DC–AC, typically employs capacitors. This paper analyzes the reasons why the use of capacitors in the DC bus cannot satisfy the grid and EV requirements, and it proposes a new DC bus configuration that utilizes energy storage batteries instead of capacitors. Due to the voltage-source characteristics of the energy storage batteries, EV instructions and grid instructions can be flexibly and smoothly scheduled by using phase-shift control and adaptive virtual synchronous generator (VSG) control, respectively. In addition, the stability of the control strategy is demonstrated using small signal modeling. Finally, typical operating conditions (such as EV pulse preheating, fast charging with variable current, and grid peak shaving and valley filling) are selected for validation. The results show that in the proposed charger, the grid scheduling instructions and EV charging/discharging instructions do not interfere with each other, and different commands between EVs also do not interfere with each other under a charging pile with dual guns. Without affecting the requirements of EVs, the grid can change the proportion of energy supply based on actual scenarios and can also obtain energy from either EVs or energy storage batteries. For the novel charger, the pulse modulation time for EVs consistently achieves a steady state within 0.1 s; thus, the pulse modulation speed is as much as two times faster than that of conventional chargers with identical parameters.

A novel virtual synchronous generator control scheme of DFIG-based wind turbine generators based on the rotor current-induced electromotive force

This paper focuses on the research of virtual synchronous generator (VSG) control technology for the doubly-fed induction generator (DFIG)-based wind turbines. The key for DFIG VSG operation is to construct an internal electromotive force (EMF) with the virtual rotor motion characteristic in the stator. The existing control schemes use the rotor or mutual flux-induced EMF as the internal EMF. Since the flux corresponds to a composite magnetic field generated together by the stator and rotor current. Any variations in the stator current caused by external disturbances will reflect on the rotor current to keep the flux constant. The rotor overcurrent is inevitable under a large external disturbance, threatening the safety of the rotor-side converter (RSC). Moreover, the flux is immeasurable. The accurate flux control depends on flux observers, increasing the complexity; while the control without observers cannot ensure the effectiveness, leading to control failure. To address these problems, a novel DFIG VSG control scheme with the rotor current-induced EMF as the internal EMF is proposed in this paper. The internal EMF is corresponded to the single magnetic field generated only by the rotor current. This can lead to the following benefits: the rotor current will not vary with the stator current and can be limited under large external disturbances, ensuring the safety of the RSC; the rotor current can be directly measured without the need for extra observers, reducing the difficulty of control implementations; the underlying controlled vector is unified with the traditional grid-following DFIG, favoring the retrofit of the installed DFIGs. Compared to the existing schemes, this scheme has a larger equivalent internal impedance. An additional rotor current-terminal voltage magnitude droop control is added to effectively restrain the problems brought by this larger impedance. Simulation and analysis results demonstrate that the proposed DFIG VSG control scheme effectively addresses problems in the existing schemes. Moreover, the results also exhibit that the scheme has a robust adaptability across a wide range of short-circuit ratios and possesses the grid-forming ability independent of SGs.

Optimization and intelligent power management control for an autonomous hybrid wind turbine photovoltaic diesel generator with batteries

In this paper, a critical issue related to power management control in autonomous hybrid systems is presented. Specifically, challenges in optimizing the performance of energy sources and backup systems are proposed, especially under conditions of heavy loads or low renewable energy output. The problem lies in the need for an efficient control mechanism that can enhance power availability while protecting and extending the lifespan of the various power sources in the system. Furthermore, it is necessary to adapt the system's operations to variations in climatic conditions for sustained effectiveness. To address the identified problem. It is proposed the use of an intelligent power management control (IPMC) system employing fuzzy logic control (FLC). The IPMC is designed to optimize the performance of energy sources and backup systems. It aims to predict and adjust the system's operating processes based on variations in climatic conditions, providing a dynamic and adaptive control strategy. The integration of FLC is specifically emphasized for its effectiveness in balancing multiple power sources and ensuring a steady and secure operation of the system. The proposed IPMC with FLC offers several advantages over existing strategies. Firstly, it showcases enhanced power availability, particularly under challenging conditions such as heavy loads or low renewable energy output. Secondly, the system protects and extends the lifespan of the power sources, contributing to long-term sustainability. The dynamic adaptation to climatic variations adds a layer of resilience to the system, making it well-suited for diverse geographical and climatic conditions. The use of realistic data and simulations in MATLAB/Simulink, along with real-time findings from the RT-LAB simulator, indicates the reliability and practical applicability of the proposed IPMC strategy. Efficient load supply and preserved batteries further underscore the benefits of the fuzzy logic-based control strategy in achieving a well-balanced and secure system operation.