Diesel Generator Set Research Articles

Influence of the shutdown process of the driveline on the generator bearing life in the diesel generator set

Diesel generator sets are commonly used as power sources in transportation due to their versatility and cost-effectiveness. During the shutdown process, the diesel engine’s cylinder compression pressure would cause forced vibration in the driveline system through the crank linkage mechanism, resulting in unsteady loads that pose a threat to the bearing life. To address this issue, a coupling forward design method is proposed that takes into account the impact of unsteady loads on bearing life. An experiment was conducted on a 16V280 diesel generator set shutdown process, and a driveline dynamic model was established. The cumulative damage value that connects unsteady loads and bearing life was introduced to quantify the effect of unsteady loads on the bearing life during the shutdown process. The unsteady loads included torque fluctuation and collision forces. The results showed that reducing the driveline key gap and increasing the coupling stiffness can decrease the combined load on bearings and improve bearing life. A large stiffness coupling was designed to achieve shutdown smoothness and a 43.19% reduction in bearing life damage, confirming the design method’s feasibility concerning bearing life.

A Bi-Level Optimization of Speed and Energy Management for Diesel-Electric Hybrid Train

Diesel-electric hybrid trains (DEHT) equipped with battery systems can effectively reduce fuel consumption and greenhouse gas emissions. For chasing the best fuel consumption efficiency, the coupled optimization problem of driving strategy and energy management for DEHT is addressed in this paper. We propose a bi-level optimization method that jointly designs driving strategy and energy management for DEHT. The optimal driving strategy is obtained by modeling a particle swarm optimization problem in fuel consumption reduction at the top level. The power allocation for the diesel generator set and the battery is described as a convex optimization problem and solved at the bottom level. The proposed method can converge to an optimal value after cyclic iterations. In each iteration, the top-level outputs the current optimal driving strategy to the bottom problem. Based on this current optimal driving strategy, the bottom level calculates the current best fuel consumption and energy management, then feeds back to the top level to start a new iteration. To verify our introduced method, the proposed optimization is compared with the common problems, such as single energy management optimization, single-speed optimization, and sequence optimization. Results show that the maximum and minimum fuel consumption reduction by the introduced optimization method is 20.0% and 2.7%, respectively.

Improving the quality of electricity in power supply systems with reservation from diesel generator plants

Subject of research: substantiation of the parameters and application of FACTS-devices of the STATCOM type for improving the quality of electricity in power supply systems with redundancy from diesel generator sets.
 Purpose of research: is to substantiate technical solutions based on semiconductor devices with reactive and active power generation aimed at improving the quality of electricity in remote power supply systems powered in backup mode from diesel generator sets.
 Methods and objects of research: fast Fourier transform, instantaneous power theory, simulation in Matlab Simulink. The object of research is the power supply system with a complete transformer substation 10/0.4 kV and redundancy from diesel generator sets.
 Main results of research: the article presents the features of ensuring the redundancy of the considered power supply system, taking into account the quality of electricity and the rationale for technical solutions to improve it when supplying the household loads of the village in the backup mode from the DGU based on simulation modeling. A spectral analysis of a sharply variable load curve was performed. It is proposed to use a three-level STATCOM at a voltage of 0.4 kV with a supercapacitor storage, which requires less storage energy than a buffer storage, to ensure the quality of electricity when powered by a diesel generator set. The results of the studies carried out testify to the prospects of using STATCOM with a storage device to improve the quality of electricity in low-voltage networks.

Challenges of renewable energy communities on small Mediterranean islands: A case study on Ponza island

Italy has reconsidered incentives on Renewable Energy Sources (RES) to implement the EU clean energy transition and Renewable Energy Communities (REC). Legislation on RECs shifted the focus of incentives from production to self-consumptions. In this paper, the REC model is studied in a minor island disconnected from the national grid, with strongly seasonal energy load and water demand. This is a typical Mediterranean scenario where energy demand is covered by Diesel gensets and water supply is provided with tankers. The implementation of RES is investigated, exploiting the current REC model of incentives. Two sub-optimal REC configurations were defined using time-dependent simulations on pyRES, an in-house code for energy systems. Results show the economical unfeasibility of REC when there is a poor mix of users. In contrast, REC can achieve economic profitability including industrial demand of a desalination unit (DES). The increase of self-consumption guaranteed from the DES allows to increase the NPV of the community and results in major cuts in CO2 emissions (60% of those related to water supply and 10% of those from Diesel gensets) and a reduction of fuel costs of 22%. This method can be applied to investigate the performance of a REC in a local environment and help stakeholders in planning the expansions of RECs on the territory.

Optimization tool for operating isolated diesel-photovoltaic-battery hybrid power systems using day-ahead power forecasts

This paper presents a computational tool based on a genetic algorithm and artificial neural network for optimizing the operation of isolated diesel-photovoltaic-battery hybrid power systems using day-ahead power forecasts obtained with quantile random forests. The optimization tool was conceived to be flexible, i.e., it can be used to operate isolated power systems with multiple configurations of diesel generator sets (DGS), to work with a reduced number of input data, and to be as simple as possible to be used. The optimization relies on combining valley-filling and peak-shaving strategies using battery energy storage systems while considering the combined forecast of demand and photovoltaic (PV) generation. The tool also simulates the behavior of the DGS to define the optimum arrangement of diesel generators considering the variability of both demand and PV generation. The output consists of hourly values of energy storage power dispatch, DGS arrangement, and, if necessary, load shedding and/or PV curtailment. The algorithm that implements the optimization tool, which is currently in the phase of field-test in the isolated diesel-photovoltaic-battery hybrid power system of Fernando de Noronha, Brazil, demonstrated a good performance in computer simulations validated with real measured data.

Multi-state optimal power dispatch model for power-to-power systems in off-grid hybrid energy systems: A case study in Spain

The electricity production from Renewable Energy (RE) in isolated locations requires long-term energy storage systems. To that end, Hybrid Energy Storage Systems (HESS), through a combination of hydrogen and batteries, can benefit from the different advantages of both technologies. This paper presents a hybrid Power-to-Power (PtP) Optimal Power Dispatch (OPD) model for isolated systems with no electric grid access. Currently, the electricity supply in such cases is usually based on a mix of RE as the primary energy source sustained by a diesel genset acting as a backup generator. In this context, the model delivers the hourly energy flows between renewable production sources, energy storage devices and the electrical load, which minimises costs and Green House Gases (GHG) emissions. For validation purposes, the model was tested through its application to a case study in an isolated area in the Canary Islands, Spain. The results show that the algorithm calculates the hourly OPD successfully for a given plant sizing, considering the defined operational states of the different assets. These operational constraints showed a decrease in the PtP round-trip efficiency of 5.4% and a reduction of the hydrogen production of 9.7%. Finally, the techno-economic analysis of the results proves that the combination of hydrogen and batteries with RE production is a feasible alternative to phasing out fossil fuels for the selected case study – reducing the diesel generator usage down to 1.2% of the yearly energy supply.

Health Condition Identification and Quantitative Assessment of Emergency Diesel Generator Sets Based on Back Propagation Neural Network and Mahalanobis Distance

To address the problem of a comprehensive assessment of emergency diesel generator set health status, a quantitative assessment method of emergency diesel generator set health status based on data-driven and distance measurement is proposed. BP neural network was used to extract the feature sequences of emergency diesel generator sets under different health states. An emergency diesel generator set health state identification model was established. To further quantitatively evaluate the health level of the emergency diesel generator set, the distance between each state of the emergency diesel generator set and the health state is measured by introducing the Mahalanobis distance algorithm, which realizes the unification of both qualitative and quantitative evaluation of the health state of the emergency diesel generator set. The operating states of diesel generator sets were subdivided into four states: healthy, sub-healthy, abnormal, and fault, and a simulation test study was conducted using the actual measurement data set of emergency diesel generator set operation. It is verified that the proposed method can classify the operating status of diesel generator sets more accurately and obtain the health assessment score index. The integration of qualitative and quantitative assessment of the health status of emergency diesel generator sets is realized, and the status warning is carried out accordingly, which provides an accurate basis for taking different maintenance and repair measures in a targeted manner.

Energy management strategy of field power station based on differential hysteresis voltage stabilization

The existing field power stations mainly use diesel generator sets for power supply, with poor power supply stability and no uninterrupted power supply capability. Therefore, a hybrid energy storage device is introduced into the field power station to improve it. According to the working characteristics of different energy sources, an energy management strategy based on differential hysteresis voltage stabilization is proposed. Hysteresis voltage stabilization control makes it true that the diesel generator set as the main energy source works for a long time, and the battery as a backup energy source works when necessary. Differential voltage stabilization control realizes coordination control of the two, which allows the battery to exit work smoothly. The strategy can get transient stability and stable economy, and extend the life of the battery. Simulation results show that this strategy is superior to the traditional hysteresis voltage stabilization strategy.

Energy Transition Scenarios in Off-grid Communities using SOFC-CHP/Battery Hybrid Systems

Today, off-grid communities rely mainly on diesel gensets with limited electrical efficiency and diesel furnaces for electricity and heat generation, respectively. The CO2 emissions associated with this electricity production can be reduced by improving the electrical efficiency of the system thus reducing the fuel consumption. Additionally, waste heat from the electricity production can be recovered for heating thus creating a combined heat and power system. In this work, a solid oxide fuel cell combined heat and power system hybridized to a battery was proposed for this purpose. Simulation of the annual electricity and heat production were performed using real temporal electrical demand data. Results showed that a reduction of up to 36 % in primary energy consumption can be reached compared with the current situation.

Assessment of a methanol-fueled integrated hybrid power system of solid oxide fuel cell and low-speed two-stroke engine for maritime application

An integrated solid oxide fuel cell (SOFC)-internal combustion engine (ICE) system was proposed in this paper. Methanol was used as the fuel in the system, meaning that the SOFC exhaust gas could not enter the engine with methanol, due to the high-injection pressure of fuel in engine and difficulty of pressurizing SOFC exhaust gas. Therefore, this paper proposed SOFC exhaust gas was delivered with engine intake air to achieve waste gas reutilization, which could also reduce oxygen concentration and increase specific heat capacity of in-cylinder gas for low NOx emissions. Two modes were proposed, including delivering SOFC anode-off gas into engine for Tier II requirements and delivering SOFC cathode and anode off gas into engine for Tier III requirements. The effects of power ratio of SOFC and engine on proposed system were analyzed based on the electrochemical model of SOFC and filling and emptying model of engine. The results indicated that increasing the power ratio in both modes led to an increase in brake power but a decrease in indicated efficiency, mainly due to the increase in energy input and the decrease in exergy-to-power conversion efficiency. In addition, at Tier III mode, the Tier III requirements (weighted average NOx was 3.35 g/kWh) were met at power ratio of around 1:2, at which the energy and exergy efficiency of system reached 55.6% and 57.9%. Furthermore, an improvement for a tanker was proposed, substituting proposed system for combination of marine engine and diesel genset. Specifically, SOFC and ICE were used for auxiliary power unit and propulsion, respectively. The results showed that it could achieve better carbon-emission and techno-economic performances. The payment period of such improvement was 3.08 years taking carbon trading and government support into account.

Investigation of hybrid power plant configurations for an offshore vessel with co-simulation approach

This work presents a full-system simulator consisting of a generic power system integrated with a vessel model and real-time capabilities. The whole system simulation facilitates evaluating the overall system performance by considering components’ interactions according to the maneuvering and environmental effects. Indeed, flexibility in the configuration and size of the power system enables the investigation of different concepts according to various maneuvering scenarios. Co-simulation approach is employed to integrate the models with various domains effectively. In addition, the bond graph modeling strategy as a power based method is used. The developed power system contains a diesel genset, a PEMFC, a battery with average electrical components, and a power management system. The configuration of the power system and size of power sources are modifiable. Various hybrid configurations and power capacities can be designed with validated power sources against marine vendors. In addition, the integrated offshore supply vessel with Dynamic Positioning (DP) and cruise controller and sea state forces induces the corresponding load demand of the operation to the power system. In summary, different operation scenarios with sea states, the thrusters’ states and allocation algorithm, DC link voltage, power electrical converters controller, and fuel consummations are captured in one model framework. To demonstrate the application of the model and emphasis the importance of total system simulation, three power system configurations are designed and simulated with two operational modes of DP and cruise with various sea states.

MSTOGI-FLL-ROGI Based Frequency Adaptive Control for a Single Stage SPVA-BES-BDC-DG Set Connected Standalone Microgrid for Remote Areas

The operation of a standalone microgrid (MG) is severely affected by the presence of local nonlinear loads at the point of interconnection (PIC), which tend to degrade the power quality of the MG. Moreover, in MGs connected with diesel generator (DG) sets, the frequency varies with loads, which leads to poor power quality due to erroneous estimation of the fundamental components. To solve these problems, this paper presents a mixed second and third order generalized integrator with a frequency locked loop (MSTOGI-FLL) prefilter cascaded with a reduced order generalized integrator (ROGI) filter-based control for a solar photovoltaic array (SPVA), a battery energy storage (BES), and a synchronous reluctance diesel generator set (SynRDG) based standalone microgrid. The control improves the operation of the MG by providing enhanced harmonic attenuation and DC offset rejection from the DG currents and PIC voltages during distorted or single-phase load conditions without degrading the dynamic performance of the filter. The control makes the filter adaptive to the DG set frequency, which enhances the filter performance. A power management scheme (PMS) is presented to utilize the SPVA-BES combination and it minimizes the DG set operation. The presented control is compared with other GI-based controls in terms of dynamic performance, frequency tracking, and filtering capability. The MG performance is analyzed under several dynamic conditions using simulation and hardware results.

State of the art of rational design of efficient mufflers

An efficient exhaust muffler needs to satisfy the rather conflicting requirements of adequate insertion loss (IL) with limited back pressure, weight, size and cost. The unmuffled exhaust noise of an internal combustion engine peaks at the engine firing frequency and the first few harmonics thereof. Designing the muffler (a wide-band low pass acoustical filter) for such low frequencies is quite a challenge. Therefore, design of efficient mufflers has remained an art as well as science. During the last two decades or so, however, (a) multi-hole cross-flow perforates, (b) multiply connected perforated pipes and baffles, and (c) the double-tuned, grazing-flow concentric tube resonators have emerged as promising constituent elements. In this paper, elements (a) and (c) have been combined ingeniously to synthesize efficient muffler configuration for diesel generator (DG) sets as well as automotive engines. Relatively simpler lumped parameter approximation for perforates opening into cavities, electro-acoustic analogies, and the simple expansion chamber equivalence of the double-tuned concentric tube resonator have been used to develop a rational design methodology. A novel feature of this methodology is incorporation of the given back-pressure limit into the acoustic design process. The resulting muffler configurations are robust and can be scaled up (and down) easily for IL as well as back pressure.

Diesel genset optimization in remote microgrids

In this paper, a new model is proposed for the real-time diesel genset optimal dispatch and unit commitment in remote microgrids. The objective is to reduce fuel consumption, while taking into account several constraints, such as maintenance considerations and prime power ratings, specific to gensets. The model described in this work is deterministic in nature and is a mixed-integer linear programming optimization problem. In order to demonstrate the correct behavior of the model, four case studies were chosen to illustrate the activation of different constraints under certain conditions. The results show that the model properly reproduces the intended behavior, and that it could have permitted to reduce fuel consumption by 4.3 % when compared to the actual dispatch during those 2 days. Finally, it was shown that the performance of the model solved with CPLEX and Gurobi is adequate for real-time optimization in remote microgrids, and that the economic gain of using a baseload strategy instead of a load sharing strategy is negligible compared to the increase of complexity in implementing this baseload strategy.

Techno-Economic Assessment of a Hybrid Solar Photovoltaic – Diesel Genset for Rural Electrification, Case study of Namabasa Village – Uganda

In recent time, hybrid renewable energy systems are increasing being utilized to provide electricity in remote areas especially where the grid extension is considered very expensive. This study presents a techno –economic analysis of a Mini grid solar photovoltaic system for five (5) typical Zonal Communities in Namabasa ward Mbale District while promoting renewable energy system adaption and rural electrification. The assessment technique includes the establishment of the socio-economic state of the rural community through a field survey. The cost of system development ,electricity tariffs and sizing of energy production are realized via the Levelized Cost of Electricity ( LCOE) technique Sensitivity analysis was carried out to identity the parameters that affect the evolution of the (LCOE) during the life of the project, the results have shown that the annual energy production at a rate of 12,693.2 Mwh/year and capacity of 1449kW, while the lowest is predict at Namabasa Zone II at the rate of 2847MWh/year a capacity of 325KW where business consumers. The standard (LCOE) for system during the 15-year lifespan in the five (5) zones is estimated 350/= per KWh except at Doko II, this cost per Kilowatt Hour is more attractive and competitive compared with the current rate charged by the National electricity company.

Improving the Energy Efficiency of a Ship’s Power Plant by Using an Autonomous Hybrid System with a PMSG

In ship systems, diesel power generators are used in various systems of autonomous power plants to ensure power supply security. This article presents an autonomous hybrid system of a ship power plant with a diesel generator with a permanent magnet synchronous generator and electricity storage in parallel topology (the permanent magnet synchronous generator is connected directly to the receiving network). The electricity storage through the active converter is connected to the receiving network in parallel with the permanent magnet synchronous generator. The decoupled control of the reactive and active power in the active converter enables stabilization of the voltage in the ship’s electrical power grid while ensuring the possibility of obtaining different operating regimes of the power plant at various stages of the ship’s operation. The innovative method of voltage stabilization presented in this article is based on the compensation of the unfavorable reaction of the permanent magnet synchronous generator armature through the optimal transmission of negative inductive reactive power from the active converter to the generator using the electromagnetic properties of the synchronous generator. The active converter controls the direction of the active power transmission between the DC source, the grid, and the permanent magnet synchronous generator. This paper proposes a hybrid autonomous power plant system using battery storage in place of a single diesel generator set against the commonly used two diesel generator sets, working in parallel, to increase the energy efficiency of the power plant by minimizing the specific fuel consumption of the diesel generator set. The article examines the possibilities of such a mechatronic system design based on analytical research and analysis of electromagnetic and energy characteristics using the Matlab-Simulink program.

State-of-the-Art Literature Review of Power Flow Control Methods for Low-Voltage AC and AC-DC Microgrids

The development of AC distribution systems provides for the seamless integration of low-voltage microgrids with distributed energy resources (DERs). This poses new challenges for the control of normal, emergency, and post-emergency states of microgrids, calling for the creation and development of information and communications technology infrastructure. Power converters/inverters that are used to integrate renewable DERs lack inertia. Along with them, fossil fuel-fired generation units are also being integrated into microgrids. These include gas generator sets, diesel generator sets, and microturbines, having small (up to 1–2 s) values of mechanical inertia constants—Tj. This leads to an increase in the rate of transients by a factor of 5–10. Under these conditions, the technical requirements for the speed of automatic power flow control systems, as well as the methods they rely on, have to be reconsidered. Microgrids include DC microgrids, AC microgrids, and hybrid (AC-DC) microgrids. In the case of hybrid microgrids, DERs are connected to the DC grid and are integrated into the AC grid through a common inverter. The complexity of the task of microgrid control is due to the need to choose properly the type and extent of control actions so as to prevent the emergence and development of accidents. The employed control methods must ensure the reliable power supply to consumers and the quality of power in microgrids, as well as the reliable operation of the external distribution systems into which they are integrated. The article gives an overview of control methods for low-voltage AC and AC-DC microgrids, which allow one to tackle effectively solve the tasks.

Experimental analysis of combustion with the use of ethanol-biodiesel-diesel blends in diesel generator sets

This study aims to experimentally investigate the effects of using different percentages of ethanol-biodiesel-diesel blends in diesel internal combustion engines and to analyze energy and combustion parameters. The experiments were conducted on a single-cylinder, four-stroke, air-cooled, and constant-speed diesel generator set with a rated electrical power of 4.5 kW and 79% of full engine load (3.54kW). Temperature, fuel flow, AVL pressure, and rotation sensors were installed on the crankshaft and inside the cylinder. The fuels used were commercial diesel (S-10) and blends with 1%, 2%, and 3% of anhydrous ethanol added to diesel, changing the injection pressure in only one blend. The results show a decrease in thermal efficiency and an increase in fuel consumption, in addition to an increase in ignition delay, an increase in combustion duration, a decrease in in-cylinder pressure, and a decrease in the heat release rate as the percentage of ethanol increased.

Clean Mobile Telecoms

Blue World Technologies has developed a methanol fuel cell that aims to replace the diesel gensets for telecoms networks.

Methodology of Analysis of Thermal Vision Parameters of NPP Standby Diesel Together with Standard Instrument Readings

Analytical studies of the results of thermal imaging control using IAS TIK together with the corresponding values of the temperature control results obtained in the standard DGS condition monitoring system were carried out within the framework of R&D for the development of an integrated automated system for thermal imaging control (IAS TIK). Approbation of IAS TIK in NPP conditions was carried out by thermography of standby diesel generator sets of NPP type 12zv40/48+S2445-12. At the same time, the parameters of the diesel engine and the generator were measured using the standard control system. The methodology is proposed that provides an analysis of the uniformity of the operation of diesel cylinders, the condition of the crankshaft bearings, the condition and quality of the generated electricity of the generator, as well as the analysis of the operation of lubrication and cooling systems. The practical application of the technique demonstrates the correspondence between the temperatures measured by the standard system and the IAS TIK. A joint analysis of the results obtained by the standard and developed systems provides an increase in the depth of the diagnostic examination and confirms the information content of the thermographic parameters and the quality of the measurement channels of the standard systems. The parameter values obtained from the analysis of the indicators of the standard control system, recorded at a steady power value, will be used in subsequent diagnostics to establish trends in these parameters