There is harmful air-pollution which mainly caused by raw-coal firing for heating purpose in Ulaanbaatar, Mongolia. Although dominantly utilization of electricity-powered warmers is good solution for this issue as same as highly developed countries, local power system currently in use has already been in over-stress during sundown interval as most of residents actively use home electric appliances. Therefore, the authors intend to lessen the polluted-ingredients of urban area air by using latest technology development. The distributed-generation system with renewable source and battery storage can be the bright solution. Within this paper, an appropriate configuration of the utility-interactive photovoltaic (PV) power generation system with energy storage (ES) for locals, and its operation principle are discussed. Subsequently, an adapted operation algorithm which gives an economical advantage, and contributes for grid impact is applied. Then, the experimental setup to verify the feasibility of recommended structure and operation algorithm is implemented. Development of the PV power generation system with ES will lead to a reduction in peak power usage, and lessened amount of CO2 emissions is expected to be resulted.

Nickel metal hybrid (NiMH) batteries are the most widely used batteries in hybrid electric vehicles (HEVs). Due to an imbalance among the individual cells caused by long-term use in HEV, a large number of NiMH batteries end up as toxic waste. Although the retired batteries cannot be employed as energy storage devices (ESDs) in electric vehicles (EVs) or HEVs anymore, they still have the potential to be reused as an energy source in small-scale distributed generation systems for households. However, the cell balancing operation is mandatory, even for those applications with lower power ratings. Hence, this paper proposes an active cell balancer that equalizes the state of charges (SOCs) of the imbalanced NiMH batteries using a generation control circuit (GCC). Along with the cell balancing circuit, an active power decoupling circuit (APDC) is applied. The purpose of the APDC is to not only achieve minimization of power pulsation caused by single-phase inverter, but also reliability enhancement of the entire system.

Growth in the electric vehicle industry has resulted in considerable chemical battery waste, which requires special recycling processes. The power and recharging capacities of waste batteries are insufficient for the operation of traction motors. However, such batteries can be reused as power sources in residential renewable energy systems because household energy demands are much lower than those of electric vehicles. To enable this reuse, a battery pack should be equipped with an equalizer. Hence, in this study, we propose a battery module equalizer that adjusts the state of charge (SOC) of each battery module to the same point using a generation control circuit (GCC). By strategically changing the duty ratio of the GCC while detecting the overall voltage of the entire battery pack, the relative SOC of each battery module can be observed while the battery system is in operation. Although this approach uses only two sensors, it enables SOC observation for the entire battery pack, leading to reduced implementation costs and form factor. The equalization current is further regulated based on the observed relative SOC. The simulation and experimental results demonstrate the rapid equalization capability of the proposed GCC-type equalizer during the discharging process.

The global shift toward electrified transportation is accelerating as nations work to reduce carbon emissions and combat climate change. Second-hand hybrid electric vehicles (HEVs) have become a practical alternative in developing countries like Mongolia due to their affordability and fuel efficiency. However, the degradation of nickel-metal hydride (NiMH) batteries in aging HEVs presents a significant challenge, particularly in Mongolia’s extreme climate conditions, which accelerate battery deterioration. Existing state of health (SOH) estimation methods often face limitations in accuracy, consistency, and practicality, reducing their effectiveness in real-world applications. This paper proposes a novel SOH observation method tailored for second-hand HEVs operating in harsh environmental conditions to address these challenges. The proposed method utilizes multiple battery parameters, including current, voltage, temperature, internal resistance, and capacity, to improve estimation accuracy while maintaining simplicity and efficiency. The effectiveness of the proposed method is validated through simulation and experimental analysis, demonstrating a correlation between predicted and actual battery health. The findings offer a reliable and practical solution for battery health monitoring, enhancing vehicle performance, informing consumer decisions, and supporting the sustainable adoption of HEVs.

Adopting and widely implementing solar photovoltaic (PV) systems are regarded as a promising solution to address energy crises by providing a sustainable and independent electricity supply while significantly reducing greenhouse gas emissions to combat climate change. This encourages households, organizations, and enterprises to install solar PV systems. However, there are many solar PV systems that have been connected to the power distribution grid without following the required procedures. Power distribution grid operators cannot detect the locations of these solar PV systems. Thus, it is necessary to assess the impact of solar PV systems on the power distribution grid in detail, even though there are multiple economic and environmental advantages associated with installing solar PV systems. This study analyzes the changes in an overloaded power distribution grid’s power losses and voltage deviations with solar PV systems. There are two main factors considered for assessing the impact of the solar PV system on the power distribution grid: the total installed capacity of the solar PV systems and the location of the connection. Based on a comparison between the measurement results of three feeders with higher loads in the Ulaanbaatar area, the Dambadarjaa feeder, which has the highest load, was selected. The impact of the solar PV systems on the selected feeder was analyzed by connecting eight solar PV systems at four different locations. Their total installed capacities vary between 25 and 80 percent of the highest daily load of the selected feeder. The results show that the power loss of the feeder can be greatly reduced when the total installed capacity of the solar PV systems is selected optimally, and the location of the connection is at the end of the power distribution grid.