Hybrid Systems I

This work is concerned with the control strategy for the parallel operation of distributed generation systems (DGS) in a standalone ac power supply. The proposed control method uses only low-bandwidth data communication signals between each generation system in addition to the locally measurable feedback signals. This is achieved by combining two control methods: droop control method and average power control method. The average power method with slow update rate is used in order to overcome the sensitivity about voltage and current measurement errors. In addition, a harmonic droop scheme for sharing harmonic content of the load currents is proposed based on the voltages and currents control algorithm. Experimental and simulation studies using two parallel three-phase pulsewidth modulation (PWM) inverters are presented to show the effectiveness of the proposed control.

Control of distributed generation systems - Part II: Load sharing control

The continuous decline of costs for renewable energy technology, together with the establishment of a mature alternative energy industry, has led to the increased utilisation of renewable energy sources for remote area power generation. Rural households in industrialised and less developed countries attach high value to a reliable supply of electricity even if its capacity is limited. The paper reviews the current state of the design and operation of stand-alone PV-diesel hybrid energy systems. It highlights future developments, which have the potential to increase the economic competitiveness of such systems and their acceptance by the user.

PV-diesel hybrid energy systems for remote area power generation — A review of current practice and future developments

This paper presents system modeling, modified space vector PWM implementation (MSVPWM), and control system design of a Z-source converter. For an electrical analysis of the fuel cell powered systems, the fuel cell system is modeled by an R-C circuit including its voltage-current polarization characteristics. A discrete-time state space equation is given to implement digital control and a space vector pulse-width modulation technique is modified to realize the shoot-through zero vectors that boost the dc-link voltage. Three discrete-time controllers and an asymptotic observer are designed.

Control of a Fuel Cell Based Z-Source Converter

On the policy of photovoltaic and diesel generation mix for an off-grid site: east malaysian perspectives

This paper presents a project undertaken in Mexico to electrify the remote village of San Antonio Agua Bendita (SAAB) using a custom designed hybrid power system. The hybrid power system will provide grid quality electricity to this community which would otherwise not have been electrified via traditional distribution lines. The hybrid power system was designed to electrify the entire community, incorporate multiple sources of renewable power with on-demand power, operate autonomously, and be cost effective in dollars per watt of electricity generated over the system's usable life. A major factor in the success of this project is the use of renewable energy for economic development and community partnership. Many rural electrification projects have provided power for domestic use but few have successfully provided power to improve the economic condition of the people served by the system. The SAAB hybrid avoids this pitfall by providing 120 VAC power at 60 Hz to anticipated industrial loads in the village, as well as providing grid quality power for domestic use. The system consists of the following modules: a controller, battery storage, a PV array, two 1O kW wind turbines, a diesel generator, a micro-hydro generater, power output control. >

J. Gutierrez-Vera

Papers

Use of renewable sources of energy in Mexico case: San Antonio Agua Bendita