Energy Management Strategies for Hybrid Power Systems Considering Dynamic Characteristics of Power Sources

Abstract

Due to the rising concern of environmental problems, fuel cell hybrid power systems have been proposed to be an ideal substitution to diesel engines. However, the hybrid power system has brought many challenges, one of which is the power splitting among different power generation technologies. In this paper, a wavelet transform and fuzzy logic based energy management strategy is proposed for a fuel cell/battery/ultra-capacitor hybrid power cruiser considering their dynamic characteristics. The energy demand of the cruiser is decoupled into different frequencies by wavelet transform and distributed to different energy sources according to their dynamic characteristics. To ensure long-term reliable operation of the hybrid power system, fuzzy logic is proposed to keep the state of charges of the battery and ultracapacitor within safe range. The proposed energy management strategy is applied to a hybrid power cruiser in MATLAB/Simulink and two cases are studied considering different initial states of charge of the energy storage system. The results show that the proposed energy management strategy enables the fuel cell to supply about 50% of the high frequency power and reduce the peak power supplied by the fuel cell by 80% -100% when the initial state of charge of the ultra-capacitor is low, and the fuel cell supplies around 400% higher than the low peak power and 20% of the high peak power when the initial state of charge of the battery is low.

Optimal Planning for Wind Turbines in Mega Seaports Considering Practical Application Constraints: A Case Study of Ningbo-Zhoushan Port

“…The comprehensive evaluation value reflects the superiority or inferiority of wind turbine selection alternatives in practical engineering. The calculation formula is as follows [34]: (7). Based on the comprehensive evaluation values, rank the alternatives in descending order.…”

“…Otherwise, it is necessary to reconstruct the judgment matrix. The consistency index and the ratio of random consistency can be obtained using Equations ( 6) and (7), respectively:…”

“…In recent years, the construction of wind power systems in ports has gradually developed in response to greening efforts. Unlike on land and offshore, port areas have more compact site utilization and harsher surrounding climatic conditions, with diverse variations in wind speed and wind energy [7]. When designing wind power systems, there are more complex factors to consider [8,9].…”

Optimization of power and energy management for fuel cell-fed hybrid electric system in marine applications

“…The Wavelet approach, as one of the global optimization algorithms, has been mentioned in [26,148,168] to decouple the power load demand into high and low frequency. Similarly, frequency-division load sharing control in [81,83] and the sensitivity function method in [141] are proposed to capitalize the multi-time scale property of the integrated hybrid power system.…”

“…As a result, global optimization PMSs are typically utilized solely for verifying different control strategies. [26,148,168] decouple the power load into high and low frequency Wavelet [81,83] capitalize the multi-time scale property of the integrated hybrid power system frequency-devision [141] handle the multi-time scale property of hybrid power system sensitivity function method [6] reduce fuel consumption and maintain FCs' performance generic programming [87] optimize the power and voltage control BBO, GA [86] lower the operation cost and limit the GHG emission requirements fuzzy logic, PSO [85] minimize the AES operating cost and the GHG emissions DP, PSO, MINLP [43,44] minimize the total fuel cost ECMS [95] decrease hydrogen consumption for FCHEV ECMS [162] balance the power supply and demand, reduce fuel consumption ECMS [156] realize the fuel consumption reduction and battery lifetime saving prediction-based scheme [129] manage a hybrid shipboard power plant with fuel cells, batteries and cold-ironing meta-heuristic approach, sine cosine algorithm [13] regulate the power electronic converter modules MPC [122] coordinate sources and loads based on future demand MPC [157] optimize the coordination between the energy storage and DGs MPC [71] address the power flow tracking between super-capacitors and batteries, and achieve energy saving prefiltering MPC [121] achieve power-sharing between different power sources and maintain the DC voltage stability PSO, MPC [70] handle the marine load fluctuations, improve system efficiency and reduce mechanical wear and tear AMPC [17,64] minimize the system's total cost MPC [57] optimize the system configuration and sizing MPC [27] optimize the ESS size, minimize the cost and emissions MPC [126] achieve optimal power distribution for EVs RL, DQL-H [133] minimize hydrogen fuel consumption and reduce battery SOC fluctuation for a FCHEV RL, Q-learning [167] mi...…”