The supply of quality energy is a major concern for distribution network managers. This is the case for the company ASEMI, whose subscribers on the DJEGBE mini-power station network are faced with problems of current ...The supply of quality energy is a major concern for distribution network managers. This is the case for the company ASEMI, whose subscribers on the DJEGBE mini-power station network are faced with problems of current instability, voltage drops, and repetitive outages. This work is part of the search for the stability of the electrical distribution network by focusing on the audit of the DJEGBE mini photovoltaic solar power plant electrical network in the commune of OUESSE (Benin). This aims to highlight malfunctions on the low-voltage network to propose solutions for improving current stability among subscribers. Irregularities were noted, notably the overloading of certain lines of the PV network, implying poor distribution of loads by phase, which is the main cause of voltage drops;repetitive outages linked to overvoltage caused by lightning and overcurrent due to overload;faulty meters, absence of earth connection at subscribers. Peaks in consumption were obtained at night, which shows that consumption is greater in the evening. We examined the existing situation and processed the data collected, then simulated the energy consumption profiles with the network analyzer “LANGLOIS 6830” and “Excel”. The power factor value recorded is an average of 1, and the minimum value is 0.85. The daily output is 131.08 kWh, for a daily demand of 120 kWh and the average daily consumption is 109.92 kWh, or 83.86% of the energy produced per day. These results showed that the dysfunctions are linked to the distribution and the use of produced energy. Finally, we proposed possible solutions for improving the electrical distribution network. Thus, measures without investment and those requiring investment have been proposed.展开更多
The electrical energy produced must be consumed at the same time, hence the need to achieve a balance between supply and demand. Therefore, the production, transport, and distribution systems together constitute an el...The electrical energy produced must be consumed at the same time, hence the need to achieve a balance between supply and demand. Therefore, the production, transport, and distribution systems together constitute an electricity network. The distribution networks are designed to deliver energy to consumers. Unacceptable voltage drops are observed in the distribution networks of developing countries such as Burkina Faso. A study was carried out on the distribution network of the city of Bobo-Dioulasso in Burkina Faso. It allowed for experimentation with the “Megger MPQ1000” network analyzer to evaluate the quality of the voltage supplied to households. To this end, tests were carried out in a public distribution station and at a few subscribers in the Sarfalao district of the city of Bobo-Dioulasso. These tests were used to assess the percentage of voltage drops. These values, which are higher than 8% of the nominal voltage, are not regulatory. The load curves of the consumers in the district were also drawn. Indeed, the period of the high load is between 19:00 and 23:00 Local Time (LT), while the period of the medium and low load is between 00:00 and 18:00 LT.展开更多
高间歇性、高波动性分布式电源(distributed generation,DG)的持续大量接入给配电网的无功电压管理带来严峻挑战,对无功优化的时效性提出了更高要求。现有电压无功控制研究普遍基于单一电压等级和三相平衡网络模型假设,但实际中低压配...高间歇性、高波动性分布式电源(distributed generation,DG)的持续大量接入给配电网的无功电压管理带来严峻挑战,对无功优化的时效性提出了更高要求。现有电压无功控制研究普遍基于单一电压等级和三相平衡网络模型假设,但实际中低压配网两侧的DG、负荷通过配电变压器的耦合互动不断加剧。同时,由于换相缺失、线路不对称布置、负荷及DG不均匀接入等因素,配电网不平衡特性日益加剧,沿用单一电压等级和三相平衡网络可致电压无功控制决策结果不合理甚至不可行。为此,提出一种基于线性规划的中低压不平衡配电网电压无功实时优化方法。具体通过中压配网静止无功发生器(static var generator,SVG)和低压配网分布式光伏逆变器的协调控制,在满足电网运行约束和控制设备能力约束的情况下,实现中低压不平衡配电网节点电压偏差的最小化。同时,为满足高间歇性DG接入对电压无功控制实时性的要求,对上述非线性电压无功优化问题进行线性化逼近,并采用CPLEX求解器对相应线性规划问题进行有效求解。最后,基于某澳大利亚真实配网开展24h仿真,验证了所提基于线性规划的中低压不平衡配电网电压无功实时优化的有效性和优越性。展开更多
文摘The supply of quality energy is a major concern for distribution network managers. This is the case for the company ASEMI, whose subscribers on the DJEGBE mini-power station network are faced with problems of current instability, voltage drops, and repetitive outages. This work is part of the search for the stability of the electrical distribution network by focusing on the audit of the DJEGBE mini photovoltaic solar power plant electrical network in the commune of OUESSE (Benin). This aims to highlight malfunctions on the low-voltage network to propose solutions for improving current stability among subscribers. Irregularities were noted, notably the overloading of certain lines of the PV network, implying poor distribution of loads by phase, which is the main cause of voltage drops;repetitive outages linked to overvoltage caused by lightning and overcurrent due to overload;faulty meters, absence of earth connection at subscribers. Peaks in consumption were obtained at night, which shows that consumption is greater in the evening. We examined the existing situation and processed the data collected, then simulated the energy consumption profiles with the network analyzer “LANGLOIS 6830” and “Excel”. The power factor value recorded is an average of 1, and the minimum value is 0.85. The daily output is 131.08 kWh, for a daily demand of 120 kWh and the average daily consumption is 109.92 kWh, or 83.86% of the energy produced per day. These results showed that the dysfunctions are linked to the distribution and the use of produced energy. Finally, we proposed possible solutions for improving the electrical distribution network. Thus, measures without investment and those requiring investment have been proposed.
文摘The electrical energy produced must be consumed at the same time, hence the need to achieve a balance between supply and demand. Therefore, the production, transport, and distribution systems together constitute an electricity network. The distribution networks are designed to deliver energy to consumers. Unacceptable voltage drops are observed in the distribution networks of developing countries such as Burkina Faso. A study was carried out on the distribution network of the city of Bobo-Dioulasso in Burkina Faso. It allowed for experimentation with the “Megger MPQ1000” network analyzer to evaluate the quality of the voltage supplied to households. To this end, tests were carried out in a public distribution station and at a few subscribers in the Sarfalao district of the city of Bobo-Dioulasso. These tests were used to assess the percentage of voltage drops. These values, which are higher than 8% of the nominal voltage, are not regulatory. The load curves of the consumers in the district were also drawn. Indeed, the period of the high load is between 19:00 and 23:00 Local Time (LT), while the period of the medium and low load is between 00:00 and 18:00 LT.
文摘高间歇性、高波动性分布式电源(distributed generation,DG)的持续大量接入给配电网的无功电压管理带来严峻挑战,对无功优化的时效性提出了更高要求。现有电压无功控制研究普遍基于单一电压等级和三相平衡网络模型假设,但实际中低压配网两侧的DG、负荷通过配电变压器的耦合互动不断加剧。同时,由于换相缺失、线路不对称布置、负荷及DG不均匀接入等因素,配电网不平衡特性日益加剧,沿用单一电压等级和三相平衡网络可致电压无功控制决策结果不合理甚至不可行。为此,提出一种基于线性规划的中低压不平衡配电网电压无功实时优化方法。具体通过中压配网静止无功发生器(static var generator,SVG)和低压配网分布式光伏逆变器的协调控制,在满足电网运行约束和控制设备能力约束的情况下,实现中低压不平衡配电网节点电压偏差的最小化。同时,为满足高间歇性DG接入对电压无功控制实时性的要求,对上述非线性电压无功优化问题进行线性化逼近,并采用CPLEX求解器对相应线性规划问题进行有效求解。最后,基于某澳大利亚真实配网开展24h仿真,验证了所提基于线性规划的中低压不平衡配电网电压无功实时优化的有效性和优越性。
