Harold R. Chamorro

Wind power impact on power system frequency response

The use of high power electronics in the large scale integration of wind power in the transmission and distribution systems can affect the system inertia response and the ability to recover frequency stability after large disturbances. Different approaches have been presented to show the system dynamic behaviour, and to quantify the wind power impact on the system inertial and frequency response. This paper gives a short overview of studies performed regarding the system inertia issues under high penetrations of wind power. Also, it presents the results of a case study to show how the system inertia can be affected by high penetrations of wind power.

Partitioning power grids via nonlinear Koopman Mode Analysis

This paper proposes a new method for partitioning power grids based on the nonlinear Koopman Mode Analysis (KMA). Grid partitioning is the fundamental problem in the controlled islanding strategy. The KMA is a new technique of nonlinear modal decomposition based on properties of the point spectrum of the so-called Koopman operator. The key idea in the proposed method is to determine a set of islanded sub-grids using KMA of data on voltage angle dynamics of every bus. The method is numerically investigated with the IEEE 118-bus test system. It is shown that the proposed method provides partitions on a multiple frequency scale as well as captures the intrinsic structural properties of a grid characterized by spectral graph theory.

Consensus control for induction motors speed regulation

Cyber Physical Energy Systems (CPES) development requires the combination of distributed intelligence to fulfill the future complex tasks and reach the increase the energy demands. Electrical Industrial Systems (EIS) are in continuous evolving integrating new technologies allowing to a better performance and increase the efficiency. This paper applies the consensus protocol for Multi-Agent Systems (MAS) to control the speed of multiple induction motors. In this paper, the behaviour of the system under different disturbances and scenarios has been simulated, thus, confirming the suitability and simplicity of this method for coordinating the control actions.

Hardware-in-the-loop simulation of PV systems in micro-grids using SysML models

This paper outlines a methodology for modeling photovoltaic systems in embedded hardware. This methodology uses the HiLeS platform to transform SysML models in Petri nets and generate VHDL code. The proposed methodology is intended for Hardware-in-the-Loop simulations of power converters and PV panels in microgrids. In addition, this methodology allows the design of MPPT controllers for their direct implementation in FPGA.

Energy management of distributed resources in microgrids

The rapid increase in the integration of distributed resources such as distributed generation (DG), demand response (DR) and electricity storage (ES) requires management schemes to integrate distributed resources into low and medium electricity networks. Energy management represents a challenge for operation of electric grids when distributed resources are merged into the network. This paper address the energy management of distributes resources considering a complete characterization of them. The feasibility of those resources is considered into a microgrid model, so, the distributed resources are integrated through of a microgrid. This paper proposes the integration of distributed resources using a microgrid concept because there are relevant advantages of this model. The operational advantages are evident from the results. The results show how effectively different energy resources can be managed into the grid in the most efficient way.

On the influence of the backlash governor settings on the frequency response in power systems

The automatic frequency containment reserve (FCR-N) is in place to keep the electric frequency within the interval 50.0 +/- 0.1 Hz during normal operation. This function is mainly provided by a number of hydropower plants where the turbine governor is set to control the discharge in proportion to the measured frequency deviation. In later years it has been shown that the disturbance damping is very low in an interval around 1/60 Hz and it is believed that proper tuning of the turbine governors that provide FCR-N can help mitigating this problem. New regulator settings have been suggested to improve the performance of the FCR-N, yet keeping the system robust and the wear on participating units at a minimum. It is now desired to investigate the possible effects of new governor settings on the overall power system frequency response. In a word, the overall performance for new governor settings are tested in a large scale power system model in this thesis paper. The frequency response with the newly suggested governor settings have been investigated when introducing a disturbance into the system. Secondly, the effects of the new governor settings on electro-mechanical oscillations are also investigated.

Prony-based on-line oscillation detection with real PMU information

Wide-area monitoring systems are a requirement in the current power systems in order to provide an appropriate monitoring, supervision and protection from undesired events. Electromechanical oscillations can provoke critical situations and affect the power transmission capability. This paper applies the Multi-Prony Analysis (MPA) to estimate the critical modes by using the tie-lines power measurements from Phasor Measuerement Unit (PMU)-data. The modes observation including an online sliding window give the frequency and damping variation allowing to detect and classify the range of the oscillation.

A high efficiency fluorescent lamp electronic ballast design

This paper presents the design and implementation of an electronic ballast for powering a fluorescent lamp. The purpose of this work is to improve the efficiency of the ballast by implementing a Series Resonant Inverter (SRI) in half-bridge configuration instead classic Series-Parallel Resonant (SPRI); in order to allow to provide the voltage steady state of the lamp. By other hand, this DC-AC converter will supply the voltage lamp ignition. Results on the proposed experimental prototype, using a fluorescent lamp of 32W, shows a better efficiency compared to traditional SPRI configurations.

Development of real-time control emulator in FPGA using HiLeS methodology

Embedded systems (ES) based on field programmable gate arrays (FPGAs) enhance the overall computational capability and relieve computational load. The lack on design and implementation methods for specific control functions in hardware limits the application of complex control techniques. Therefore, a design methodology approach is showed in the current work. Fuzzy, LQR, and PI control systems are modeled using HiLeS-RCP (High Level Specification of Embedded Systems-Rich Client Platform), a methodology that links the requirements formalization step using SySML and the virtual prototyping based on Petri Nets which takes place in the system design within the process of functional modeling, generating VHDL-AMS code to implement in FPGA.

Supervisory Control for Interleaved Boost Converters using HiLeS-Designer

This paper presents the application of HiLeS (High Level Specification of Embedded Systems) formalism to design a supervisory controller based on FPGA for interleaved boost converters. This controller is intended to increase the versatility and efficiency of interleaved boost converters. Furthermore, the proposed supervisory controller uses Petri nets for structural analysis and stability. HiLeS-Designer tool, which is a platform based on HiLeS formalism, is used to design and implement the supervisory controller in embedded hardware. This approach uses the digital component of VHDL-AMS code generated by the HiLeS-Designer tool to implement the supervisory controller in FPGA. Simulations and experimental results show that the proposed control strategy increases the operating range and efficiency of interleaved boost converters.