共查询到19条相似文献,搜索用时 203 毫秒
1.
2.
海上风电经长距离高压交流海底电缆接入电网,海底电缆容升效应显著,容易引起工频过电压,同时电力电子器件和线路电容引起的谐波谐振问题也严重影响着电网电能质量,因此进行海上风电场无功配置时应充分考虑过电压和谐波谐振问题。针对上述问题,建立了海上风电场谐波模型,对海上风电场的谐波模态阻抗进行扫描,继而分析海上风电场的谐振特性;然后研究了海上风电场无功特性,计算各种发电出力水平和并网点电压下的风电场无功缺额;接着以降低综合成本为目标,以静态电压稳定裕度、最小补偿容量、谐波谐振及过电压为约束,进行海上风电场无功优化配置;最后通过Matlab/Simulink仿真验证所提方法的有效性。 相似文献
3.
4.
5.
6.
7.
考虑传统无功调节设备调节次数限制和双馈感应电机无功容量限制等约束条件,提出一种基于双馈感应电机与传统无功调节设备协调控制的分时段分层无功优化策略。首先,该策略采用谱系聚类算法对预测等效负荷曲线进行分段;其次,在每个时段采用分层调控策略进行无功优化,建立以网损和平均电压偏离度之和为目标函数的无功优化模型,上层利用改进粒子群算法计算出包括双馈感应机组在内的各种无功调节设备的优化运行状态,并预先对变压器、电容器动作;在此基础上,下层利用双馈感应机组的无功调节能力对上层优化得出的并网点电压进行自动跟踪控制,由此实现了每个时段内接入点电压控制和全局无功优化相结合,最后以IEEE33节点配电系统为算例来验证上述策略的有效性。 相似文献
8.
9.
随着风光储以及电动汽车的迅猛发展,高比例分布式能源和大量电动汽车接入配电网,导致电网控制难度增加,电压稳定性降低,有功网损增大。在高比例光伏和电动汽车接入配电网的基础上,接入储能装置,利用无功补偿装置对该配电网进行无功优化调节,构建了含PV,EV,DS,SVG的无功优化数学模型,并且利用粒子群算法进行寻优,最后通过IEEE30节点进行验证。根据结果分析可知,利用粒子群优化算法求解投切电容器组数的方案相较于传统投入固定电容器组数的方案,其网损明显降低,系统优化率大大提高。以22:00节点电压为例,优化后全时间段节点电压在0.94 p.u.~1.05 p.u.之间,电压波动较优化前趋于平缓,电压质量有所提高;采用PSO算法进行寻优计算,运行结果证明该算法收敛速度快、寻优能力强,验证了所提出的无功优化模型的有效性。 相似文献
10.
11.
Brahim Berbaoui 《International Journal of Hydrogen Energy》2018,43(12):6275-6293
This paper is proposed to establish an optimal control method for UPQC (Unified Power Quality Conditioner) to improve power quality and manage effectively equal power sharing between shunt and series inverter of UPQC under electrical faults condition. The UPQC is modeled to protect sensitive load from source side voltage disturbances under nonlinear load conditions. A hybrid power generator that integrates a proton exchange membrane fuel cell (PEMFC) as the main energy source and a super capacitor (SC) as secondary source is proposed to feed the FACT device. In this work, a new control strategy is presented for considering the voltage sag, power factor and total harmonic distortion (THD) as multi-objective of UPQC controller. For this purpose, a new powerful algorithm named virus colony search (VCS) is used for determining the coefficients of the PI controller of UPQC. By using the fuzzification process for the objectives function, a suitable fitness function is established for the optimization method. From the simulations, it can be seen that the results obtained by the proposed algorithm are best and attractive compared to other method. Consequently, the proposed strategy is effective and outstrips other strategies. 相似文献
12.
Power quality improvement using fuzzy logic controller for five-level shunt active power filter under distorted voltage conditions 总被引:1,自引:1,他引:0
In this paper, a five-level inverter is used as a shunt active power filter (APF), taking advantages of the multilevel inverter such as low harmonic distortion and reduced switching losses. It is used to compensate reactive power and eliminate harmonics drawn from a thyristor rectifier feeding an inductive load (RL) under distorted voltage conditions. The APF control strategy is based on the use of self-tuning filters (STF) for reference current generation and a fuzzy logic current controller. The use of STF instead of classical extraction filters allows extracting directly the voltage and current fundamental components in the α-β axis without phase locked loop (PLL). The MATLAB fuzzy logic toolbox is used for implementing the fuzzy logic control algorithm. The obtained results show that the proposed shunt APF controller has produced a sinusoidal supply current with low harmonic distortion and in phase with the line voltage. 相似文献
13.
由于电弧炉在运行过程中的功率因数低,无功功率波动急剧,负载变化大,产生大量的高次谐波电流,电压畸变,对电网产生不利影响,严重影响电能质量,造成大量的能量消耗,同时影响工业产量和质量。通过对电弧炉运行时的电气特性进行分析,采用TCR_TSC型SVC协调控制的补偿方法对无功进行补偿,滤除谐波。MATLAB/ Simulink仿真结果表明该装置滤波效果良好。 相似文献
14.
含分布式发电系统的配电网无功优化研究 总被引:2,自引:0,他引:2
引入有功网损、电容器以及分布式发电的费用,并充分考虑了电压质量和无功补偿容量作为罚函数的综合目标函数,采用PSO算法时运用改变更新方式,并在后期引进变异因子,建立了含分布式发电系统的配电网无功优化模型.通过算例表明,验证了模型和算法是可行的,具有较强的收敛性,对分布式发电并入配电网的运行具有一定的参考价值. 相似文献
15.
农村配电网无功补偿是保证电网安全、经济运行的重要手段,是降低电网损耗、提高电压质量的重要措施。基于此,提出了一种农村配电网无功补偿方法,该方法首先建立农电网无功优化规划数学模型,然后针对无功优化问题的特点,采用免疫遗传算法对数学模型进行求解。通过实际算例和结果分析,表明了所建立无功优化规划模型的合理性和免疫遗传算法的有效性。 相似文献
16.
Harmonic control using matrix converter of unbalanced input voltage supplied from solar power system
Most of the renewable energy sources are not distributed directly to consumer. It gone through several section to get optimum output voltage and current with the almost zero distortion. Direct Matrix converters are well known of its better power quality and low power distortion to the reactive loads. Conversely, multilevel H bridge inverters are broadly used to attain a sinusoidal output voltage in solar photovoltaic application. Reactive power is subject to high importance for the operation of alternating current (AC) power systems. Moreover there is always a challenge to obtain the balance current control from an unbalanced supply voltage with minimum harmonic distortion for reactive load application from solar power system. The main objective of the proposed system is to maximize the power usage by maintaining the current and power factor nearby unity. There are many different optimization techniques are used so far in matrix converter, a novel method of optimization BAT algorithm is proposed for the power quality to get the best result. This work mainly deals with the compensation of reactive power used in Solar Photovoltaic Power System. Bidirectional energy flow is possible with matrix converter for battery charging. Simulation results are presented to confirm the appropriate operation of the system under different of operating conditions. Also, in the proposed method the percentage of the higher order harmonics can reduced less than 9% of matrix converter for solar photovoltaic application. 相似文献
17.
高渗透率的间歇性分布式电源(DG)使微网在并网或孤岛模式的运行可靠性降低,而传统的无功优化方法往往因忽略微网可靠性导致优化效果较差。依据有功及无功功率充足和电压极限限制,以概率方式来评估微网的可靠性,提出了一种微网在并网及孤岛模式下的无功优化规划模型,以系统年电能损耗最小和微网可靠性最大为目标进行求解。最后,采用PGE 69节点进行算例分析,研究了优化系数的作用效果和算法的鲁棒性,并通过成本-效益分析来确定系统的电容器组的最优容量。结果表明,对微网进行分布式无功电源的优化配置能有效改善网损,并提高系统的可靠性。 相似文献
18.
随着大量出力随机波动型的分布式电源并入配电网中,使得基于并联电容器等静态无功补偿装置的无功调节方式不能满足新的配电网络结构下的无功优化要求。提出了一种利用SVG动态无功补偿以稳定其并网点电压的无功控制策略,并详细分析了SVG容量的选取方法。在此基础上,提出了一种含有出力随机型及其他不同类型分布式电源的配电网无功优化策略,并利用改进的粒子群算法,充分验证了所提出方法的可行性及改进粒子群算法的快速有效性。 相似文献
19.
以传输线联网的光伏逆变器为研究对象,当传输线中分布电容较大不能忽略时,考虑传输线分布电容的影响下,分析系统的谐振特性以及电网背景谐波在传输线中的传播特性。针对系统的谐波谐振情况,提出基于电容电压的有源阻尼策略有效抑制系统出现的多个谐振尖峰,同时抑制电网中5次背景谐波的传播放大。为更好地抑制7次背景谐波,在上述控制算法的基础上于电容电压反馈通道中引入7次谐振控制器重塑逆变器输出的7次谐波阻抗。最后,在所提方案下,对逆变器输出5次谐波阻抗进行约束来优化控制参数,有效减小背景谐波导致的入网电流畸变。仿真验证所提方案的正确性和有效性。 相似文献