16 - Captive (Emergency) Power Generation

The DG (Diesel Generator) set generally operates at the low power factor due to the harmonics and reactive power demand of the loads and its voltages and currents deteriorate because of unbalanced and/or nonlinear loads. Moreover, in the existing system, the solar photovoltaic (PV) plant operates during the daytime only at unity power factor. Hence, the utilization factors of both the DG set and the solar PV plant are poor. This paper presents the use of a solar PV plant to improve the utilization of the DG set by controlling its voltage source converter (VSC). The VSC regulates its currents to reduce the flow of the reactive component currents, negative sequence currents, and harmonics currents in the DG set. In this work, an adaptive algorithm is used to filter the nonlinear load currents and perturb and observe (P& O) based tracking algorithm is used to extract the maximum power from the solar PV array. A simulation study is carried out to show the effectiveness of this work and to validate the performance of the control algorithm.

This paper discusses the unit template control strategy for load balancing and voltage regulation of induction generator based DG (Diesel generator) set for islanded system. The proposed system consists of DG set along with DSTATCOM (Distributed Static Compensator) and BESS (Battery Energy Storage System) is used for load balancing along with harmonics elimination and reactive power compensation. An isolated T-T Connected transformer is used to reduce size of two-leg VSC and also neutral current compensation. The battery on two-leg VSC (Voltage Source Converter) of DSTATCOM with BESS is able to supply active power when the load requirement is more than rating of DG set and battery can store energy when load requirement is less than DG set rating. The reference sources for two-leg VSC are estimated using unit template control strategy and this algorithm has quick dynamic response. The proposed DG set system with DSTATCOM is modeled in MATLAB R2009a along with Simulink and results are verified under three phase linear/non-linear loads.

Renewable energy sources powered charging station (CS) is necessary for the sustainability of electric vehicle (EV). Therefore, this paper uses photovoltaic (PV) array and wind energy conversion system (WECS) as main energy sources for the EV charging station. Moreover, diesel generator (DG) set and grid power are also used as back-up power providing the continuous power to the EV. The charging station, has the provision to power the local house hold loads using PV array and WECS energy in islanded and grid or DG set connected modes. While charging EV and feeding household loads, the charging station compensates for the local reactive power and harmonics current demand for achieving unity power factor (UPF) operation of the grid or a DG set. In addition, various other complementary features of the charging station such as a vehicle to home, vehicle to grid, harmonics elimination, vehicle to grid reactive power compensation, and synchronization capability are considered in this work. Prototype of the proposed charging station is developed in the laboratory and steady state as well as dynamic test results are discussed in detail.

In this paper, a solar photovoltaic (PV) array, a battery energy storage (BES), a diesel generator (DG) set, and a grid-based EV charging station (CS) enable continuous charging of electric cars (EVs) in islanded, grid-connected, and DG set linked modes. The CS's primary function is to use a solar PV array and a BES to power the EV battery. The shared link voltage and the grid/generator voltage are synchronized to allow continuous charging. On the mains side, a fuzzy logic processor is used to analyze and decrease overall harmonic distortion. CS also oversees active/reactive power transfers from cars to the grid, residences, and other vehicles in order to increase operational efficiency. The CS, however, makes intelligent use of grid or DG electricity. When the solar PV array production is unavailable and the storage battery is depleted. The power from DG sets is drawn so that it always operates at 80% to 85% loading in order to get the best fuel economy under all loading conditions. Furthermore, the CS works with the storage battery to regulate the generator's output and frequency in the absence of a mechanical speed regulator. Furthermore, it ensures that the power drawn from the grid or DG set has a power factor of unity even in the case of erratic loads. The grid/generator voltage and the shared coupling voltage location are synchronized to enable continuous charging. Additionally, a fuzzy logic processor is used to analyze and minimize the overall harmonic distortion at the grid side. To improve its operational efficiency, the CS performs vehicle-to-vehicle power transfers, vehicle-to-house power transfers, and vehicle-to-grid active/reactive power transfers in addition to simulating and analyzing its performance.

Diesel Generator (DG) sets are used in industries as backup power sources which will automatically start up when grid supply is lost. In order to reduce fuel consumption, DG sets are synchronized with solar power plants dually monitoring the load requirements in industries so that DG sets will work under the optimum condition of 30% load when excess solar power is available. There will be no problem when the load is higher than the solar power supply, solar power is fully consumed and the remaining power required for load is taken from DG. But, if the load is lesser than to the solar power supply after the load is fed using solar power, the remaining power left in solar will reverse back to the DG set which causes tripping and also damages the key components of the generator. To curb this problem, an electronic controller is designed to control the operation of DG and solar plants so that solar power can be used efficiently by using LabVIEW software.

The frequency of an isolated microgrid (MG) varies with the loading condition based on the droop characteristics of diesel generator (DG) set. Although droop controllers are used to increase or decrease generation to match the loads and to reduce frequency variations, it takes more time as mechanical time constant is more than electrical time constant. The frequency variations cause system instability due to improper active and reactive power flow and degrade the power quality of the system. DG set side power quality problems exist in presence of nonlinear loads. This paper aims to make the system frequency adaptive in islanded condition as well as to mitigate the power quality problems in presence of nonlinear loads and, also, during single phase loads. In this work, a mixed second and third order generalized integrator with frequency locked loop (MSTOGI-FLL) cascaded with reduced order generalized integrator (ROGI) based control is used to eliminate the harmonics and DC offset from the DG voltages and currents, and to make the system frequency adaptive. The standalone system comprises of a single stage solar photovoltaic (SPV) array, a synchronous reluctance generator (SyRG) based DG set and, a battery energy storage (BES) interfaced with a bidirectional converter (BDC). SPV is operated by perturb and observe (P&O) MPPT. The DG set is operated in its fuel economic zone (FEZ). The system performance is analyzed under several dynamic conditions using developed simulink model.

Air pollution has become a growing problem in megacities and large urban areas throughout the globe, and transportation is recognized as the major source of air pollution in many cities, especially in developing countries. Contribution of automobiles is reported in the range of 40 to 80% of the total air pollution. The challenge facing megacities is how to reduce the adverse environmental impacts and other negative effects of transportation without giving up the benefits of mobility. This research paper includes the testing of bio-signal ring developed by Wellan International Limited for reduction of pollution levels in petrol and diesel vehicles and generator sets. The ring when attached to the inlet of the fuel pipe acts on the fuel through bio-signals. The bio-signals help in atomization of the fuel and reduce the pollutants by further enhancing the combustion process, and thus reducing the un-burnt pollutant particles from the exhaust. The ring was tested on diesel engines, petrol engines and generator sets. For diesel engine and generator set, reduction in smoke was measured, while in the petrol engine parameters such as CO, CO2, SOx and NOx were measured before and after attaching the ring. The percentage reduction of the pollutants obtained from the ring for the diesel engine is about 16.4%, and in petrol engine, significant reduction in the pollutants is observed. The average reduction in the opacity of the diesel generator set exhaust was 54.7%. Therefore, it is evident that the device can effectively control the issue of rising air pollution levels in residential, commercial as well as industrial zones.

This paper presents the operational strategy and controller implementation of a grid-interactive hybrid AC/DC microgrid for remote areas, which possess favorable wind and solar generation capabilities but have unreliable grid connection. The AC/DC microgrid, operable in both gridinteractive and islanded conditions, employs wind generation through doubly-fed induction generator (DFIG), meanwhile, solar generation is facilitated by a solar photovoltaic (SPV) array. During islanded operation, the self-sufficiency of the microgrid to supply local AC/DC loads, is assisted by a diesel generator (DG) set. For economic benefits, the DFIG and SPV array are operated for peak power extraction, while the DG set is operated within an optimal fuel utilization zone. The microgrid structure is instilled with an uninterrupted supply feature at all possible operating modes, as well as with a seamless mode transition functionality. These features are administered through the controlled operation of three distinct solid-state transition switches. The overall microgrid control framework utilizes an arctangent least mean logarithmic square (ATLMLS) algorithm. The ATLMLS-based control framework is designed to enable smooth operation at mode transition scenarios, while ensuring uninterrupted supply for local loads. The AC/DC microgrid operation and control are verified using results from MATLAB/Simulink platform.

In recent years, microgrids (MGs) with renewable energy sources, diesel gen-sets, and droop-controlled converters have been increasingly used to guarantee the continuity of power supply in remote areas. Renewable energy sources have been typically connected to MGs by using an electronic converter that features the two controllers: a current-control loop and a phase-locked loop (PLL). Stability issues related to the PLLs application in electrical grids have already been addressed in the literature; however, dynamic interactions in MGs caused by PLLs have not been sufficiently explored. In this article, an MG that includes a grid-feeding voltage source converter and a grid-forming device (diesel gen-set or converter) is studied. All network elements are modeled analytically and the eigenvalue and participation-factor analyses are used to analyze the interactions between the devices. It is demonstrated that MGs formed by diesel gen-sets have reduced stability limits. Also, it is shown that stability margins of MGs formed by droop-controlled converters can be improved by changing the control parameters (e.g., PLL and internal controllers bandwidths). The main findings and conclusions are summarized and presented as a practical MG design guide. Theoretical results are validated in a lab environment comprising two 15 kW converters and one 75 kW grid emulator.

Feedback energy recycling is one of the most important energy-saving technologies of diesel generator sets. The current methods of recovering feedback energy are mainly by the energy storage device. However, this method has disadvantages such as the big cost and large area of space. In order to improve the efficiency of feedback energy recycling, the use of feedback energy saving diesel generator set is an effective solution. By improving diesel generator set control system algorithm and ensuring the safety of diesel generator sets, the feedback energy can drive diesel generators running. After the actual verification, this solution is correct, the improved algorithm is effective and the energy-saving effect significantly.

Renewable sources equipped AC/DC microgrids in rural areas need to be augmented with diesel generator (DG)-set for reliable power deliverability at prolonged grid outage scenarios. In view of this, a DG set equipped AC/DC microgrid along with the control strategy is presented in this work. Here, multiple doubly-fed induction generators (DFIGs) and multiple solar photovoltaic (SPV) arrays are employed for wind and solar power generations, respectively. In this microgrid topology, the operation of DFIGs are in no way influenced by any of the grid voltage irregularities like unbalance or distortions. Microgrid control is devised for a decentralized implementation, and it ensures disruption-free power to local loads, while, also enabling smooth transitions among different operating states. The disconnections and reconnections of DFIGs and DG-set from the microgrid effectuate these operating states. A logarithmic hyperbolic cosine filter (LHCF) is utilized in the microgrid control strategy. In a healthy grid scenario, the control strategy operates to inject a constant power into the grid even amidst intermittencies in wind, solar, or load powers. Meanwhile, at prolonged grid outage when the integration of DG-set becomes indispensable, the control strategy operates to ensure an optimal consumption of diesel fuel from the generator. The AC/DC microgrid operation and the LHCF-based control strategy are validated through simulation results.

Electric propulsion systems have been recently used very often in various transport units. Traction electric motors can be powered, along with other consumers, from a uniform power station (UPS) of a selfsupporting unit. The application of a UPS promotes reliability and simplifies maintenance of the self-supporting unit’s electric system as the number of components of the latter is reduced. As a rule, a UPS is constructed on the basis of diesel generator sets (DGSs) of constant rotation frequency. The cost effectiveness of an electric station can be improved with the use of DGSs of varying rotation frequency. In this case, fuel economy is achieved by generating optimal shaft rotation frequency of the internal combustion engine, corresponding to the lowest brake-specific fuel consumption. The list of Russian and foreign published works dedicated to this topic is rather short, especially concerning research on the dynamic mode of work, the development of a mathematical model for the unit, and creation of a control system for a UPS with a DGS of varying rotation frequency. This article addresses the above issues, contains mathematical and simulation models of a self-supporting unit’s UPS with a DGS of varying rotation frequency, and shows the results of modeling.

The optimal location of renewable distributed generations (DGs) into a radial distribution system (RDS) has attracted major concerns from power system researchers in the present years. The main target of DG integration is to improve the overall system performance by minimizing power losses and improving the voltage profile. Hence, this paper proposed a hybrid approach between an analytical and metaheuristic optimization technique for the optimal allocation of DG in RDS, considering different types of load. A simple analytical technique was developed in order to determine the sizes of different and multiple DGs, and a new efficient metaheuristic technique known as the Salp Swarm Algorithm (SSA) was suggested in order to choose the best buses in the system, proportionate to the sizes determined by the analytical technique, in order to obtain the minimum losses and the best voltage profile. To verify the power of the proposed hybrid technique on the incorporation of the DGs in RDS, it was applied to different types of static loads; constant power (CP), constant impedance (CZ), and constant current (CI). The performance of the proposed algorithm was validated using two standards RDSs—IEEE 33-bus and IEEE 69-bus systems—and was compared with other optimization techniques.

The parameters of an electrical power system have wide variations during the operation of electrical devices; these changes are required to be measured using an accurate meter. A cost-effective Digital Sampling Multi-meter (DSMM) using a microcontroller and two sensors was proposed to overcome the complexity of traditional power meters. Voltage and current signals from sensors were discretely time-sampled and then analysed based on the Instantaneous Power Calculation Algorithm (IPCA) using an Arduino to measure six of the electrical quantities. It Root Mean Square (RMS) terminal voltage and load current, real, reactive, and apparent power, and finally Power Factor (PF), then these were displayed on both the LCD and the PC serial monitor. Also, the instantaneous waveforms of the voltage, current, and power are easily analysed and plotted with any type of load. The IPCA algorithm was adopted because of its real-time measurement, high accuracy, ease of implementation, and low cost. Measurements are performed for linear loads (resistive, inductive, and capacitive) and non-linear loads (rectifier circuits). The proposed meter's accuracy was found to have acceptable relative percentage errors for most measured parameters, especially at linear loads (maximum relative error for Vrms 0.7% at inductive load, 5% for Irms at capacitive load, and 5% for PF at capacitive load), calculated based on the FLUKE Power Quality Meter, which was considered a high-quality measurement instrument.

Comprehensive methodology for the integrating of the organic rankine Cycle-ORC with diesel generators in off-grid areas: Application to a Colombian case study