【作者】 孟镇；

【导师】 朴在林；

【作者基本信息】 沈阳农业大学 ， 农业电气化与自动化， 2013， 博士

【摘要】 变压器是电力工业的主要设备之一,它在传输电能的同时也在消耗着电能。在我国整个电网的损耗当中,变压器的损耗所占的比重是最大的,其损耗占电网总损耗的60%以上。其中,中低压配电网由于使用了大量的配电变压器,使得配电变压器的损耗大约占变压器总损耗的30%左右。因此,推广研制高效节能的配电变压器来减少其损耗已经成为电力系统节能工作的重点之一。我国农村电网的负荷具有用电集中、季节性负荷变化大、峰谷差异明显以及年平均负载率低等特点。这样就在配电变压器容量选择的问题上提出了难题,如果按照平均负荷或者最小负荷来选择配电变压器的容量就会在用电旺季出现比较严重的过负载现象；如果按照最大负荷来选择则会使变压器长期处于“大马拉小车”的状态,造成大量不必要的电能浪费。在这种情况下使用调容变压器,既可以使变压器在轻载时处于经济运行状态,又能够确保变压器在用电高峰时的供电容量充裕,最终达到降低变压器综合电能损耗的效果。因此,研究配电变压器调容的相关技术具有十分重大的现实意义。论文根据我国农村配电网的特点,针对无载调容配电变压器与机械式有载调容配电变压器的缺陷与不足,对配电变压器的有载无弧自动调容技术进行研究。在分析调容变压器调容原理以及降损节能原理的基础上,提出了一种配电变压器有载无弧自动调容临界经济容量的选取策略。该选取策略是以经济运行方式为基础来进行选择的,应用该选取策略对各容量组合调容变压器的临界经济容量进行了计算。在此基础上,分析有载调容配电变压器的有功损耗率与负载率之间的关系。同时以SZ11-M-T315(100)和S11型额定容量为315kVA的配电变压器为例,对比分析了两者的效率特性。根据实际的日、月负荷曲线对有载调容配电变压器与单一容量配电变压器的动态损耗进行计算分析,结果显示使用调容变压器的节电效果十分明显。在分析现有调容变压器缺陷与不足的基础上,提出了以反并联晶闸管作为调容开关的配电变压器有载无弧自动调容的总体设计方案以及调容开关的布置方案。通过计算调容开关在使用中所承受的电压、导通时流过的电流情况,从理论上验证了以晶闸管作为配电变压器有载无弧自动调容开关的可行性。在介绍晶闸管工作原理、特性以及相关参数的基础上,对晶闸管阀组中晶闸管串联个数以及动态、静态均压电路的参数进行了相关计算。提出了一种配电变压器有载无弧自动调容的控制策略。该控制策略以在线负荷与基于灰色负荷预测模型预测的负荷共同做为调容依据,以某单班制企业的实际数据为例,利用该控制策略对其进行容量调节,有效地避免了负荷由于短时波动而引起调容开关频繁切换的弊端。在MATLAB/SIMULINK中搭建了有载无弧调容变压器的仿真模型,对某单班制企业中使用本控制策略的有载无弧自动调容变压器进行仿真分析,验证了本控制策略的实用性与有效性。对配电变压器有载无弧自动调容的控制系统进行研究设计。该控制系统通过三相电能专用计量芯片ATT7022B对变压器低压侧的电压、电流进行数据采集生成在线负荷,主控芯片ATmega128根据本文所提出的控制策略发出相应的控制指令,由基于MOC3061的低压侧晶闸管触发电路触发导通有载无弧自动调容配电变压器低压侧对应的调容开关,由晶闸管阀光电触发与在线监测的方式来触发并监测变压器高压侧对应的晶闸管阀组。针对论文提出的配电变压器有载无弧自动调容的各种优化方法,通过实例进行计算和仿真分析,结果验证了论文提出方案的正确性和有效性。更多还原

【Abstract】 The transformer is one of the main equipments in the electricity industry. It also consume energy during the transmission of electrical energy. The transformer loss is the largest in the entire power loss in our country, which accounts for more than60%of the total power loss. Lots of distribution transformers are used in the low-voltage distribution network, which make the power loss of distribution transformers occupy30%i n the total transformers power loss. Therefore, developing and spreading the efficient energy-saving transformer become the main work in the field of energy saving in electric power system.The rural loads in our country have such characteristics, for instance electric centralized, seasonal load changing greatly, obvious difference between peak and valley and the low annual average load rate. Therefore, it is difficult to choose the proper capacity of distribution transformers. If the capacity of distribution transformers is chosen according to the average load or minimum load, then, it will emerge serious overload phenomenon in the peak of power consuming; If the capacity of distribution transformers is chosen according to maximum load, then, the transformer can not be fully operational in long time,and caused a lot of waste of electric energy. Based on these, the regulating capacitive transformer will not only make it run with the economic state under low load, but also make sure the transformer can supply enough power energy during the peak of consuming. Finally, it can reduce the comprehensive energy consumption of transformer. Therefore, researching regulating capacity technology of distribution transformer is of great realistic significance.According to the characteristics of China’s rural distribution network, and aiming at the shortcomings of no-load regulating capacity distribution transformers and mechanical on-load regulating capacity distribution transformers, this paper studies distribution transformer on-load automatic regulating capacity technology without arc.Based on the regulating capacity principle and loss reduction and energy saving principle, it proposes a kind of selection strategy of critical economic capacity for distribution transformer on-load automatic regulating capacity technology without arc. The method is selected based on the economic operation and calculates the critical economic capacity.Based on this, it analyses the relationship between the active power loss rate and the load rate of the on-load regulating capacity distribution transformers. Meanwhile, this paper takes the example of SZ11-M-T315(100) and S11distribution transformers, and compares the efficiency characteristics. In this paper, Calculating and analysising the dynamic loss of the on-load regulating capacity distribution transformers and the single capacity distribution transformer based on the daliy and monthly load curve, the results show that the regulating transformer has an obvious power saving effect.Based on the defects and shortcomings of existing regulating capacity transformer, the paper proposes the overall arcless on-load automatic capacity regulation design and regulating capacity switch arrangement.By calculating the withstand voltage and conduction current, it proves the feasibility about the issue which was proposed above that the thyristor is used as the regulating capacitive switch. Based on the introduction of thyristor working principle, characteristics and related parameters, the paper calculates the numbers of the thyristors series in thyristor valve group,and circuit parameters of dynamic and static average voltage.This paper proposes a kind of arcless automatically regulating distribution capacity control strategy. This control strategy bases on online load and the load prediction from grey load forecasting model, takes the actual data from a single-shift system as real examples, then regulates the capacity using the control strategy, which avoid the malpractice that causes by the regulating capacitive switch changes frequently. Build a simulation model for arcless on-load automatic capacity regulation distribution transformer under the MATLAB/SIMULINK,and simulation analysis the arcless on-load automatic capacity regulation distribution transformer to some single-shift enterprise, test and verify the validity and practicability of this control strategy.This paper researchs and designs the control system of arcless on-load automatic capacity regulation distribution transformer. The system captures the voltage and current data from low-voltage side of the transformer through a three-phase power metering chip ATT7022B, which generates a online load. The master chip ATmegal28sends corresponding control command. MOC3061low voltage side thyristor trigger circuit triggers the regulating capacitive switch which is corresponding to the low voltage side of the arcless on-load automatic capacity regulation distribution transformer, meanwhile, thyristor valve photoelectric trigger and online monitoring together triggers and monitors corresponding thyristor valve group of the high-voltage side of the transformer.According to the different kinds of optimization methods of arcless on-load automatic capacity regulation distribution transformer, this paper analyzes the caculation and simulation.The results show the scheme that is introduced in the paper is correct and effective.更多还原