电力系统无功补偿林力

“地方电力系统无功补偿”设计任务书•贵州电力职业技术学院：林力总体思路：1、分析原始资料；2、求各元件参数，作等值电路；3、首先假设末端电压Ud'=9KV,经过计算后发现不满足要求，于是假设末端电压Ud'=9.4KV,经过计算满足要求，但是这只是在最大运行方式下最接近于零，最小运行方式下略大了点；4、再假设末端电压Ud'=10KV，经过计算满足要求，但同样只是在最小运行方式下最接近于零，最大运行方式则大了点；5、结论：在最大运行方式下，选择Ud'=9.4KV、在最小运行方式下，选择Ud'=10KV；6、对主系统进行潮流计算；7、根据潮流计算的结果分析，发现与送入主系统功率的功率因数不得高于0.8的规定不符，因此按照0.01元\kvar.h计算罚款；8、计算主系统与地方网上的网损；9、总结；10、结束语；一、原始资料分析在某一实际地方电力系统中，有一电厂，装机容量为3*800KW，功率因数0.8常年可发。一条10KV线路向本地方负荷供电，另一条35KV线路与主系统相连，将多余电力送入主系统或从主系统受电。按原电力系统电源及负荷点情况，简化后的接线图如下：注:图中负荷的单位为（kW＋jkvar），括号外为最大负荷，括号内为最小负荷。按规定，送入主系统功率的功率因数不得高于0.8，否则罚款0.01元/kvar·h，本地方电压水平不得低于额定电压的5%，为此，该地方电网管理机构决定进行无功补偿、及电压无功的综合控制来提高供电质量和经济效益。二、设计任务利用电力系统潮流计算分析当前电网存在的问题。线路型号电阻Ω/kM电抗Ω/kMLGJ-500.650.42LGJ-251.070.37表二：架空线路参数表一：变压器参数变压器型号短路损耗(PK)W空载损耗(P0)W阻抗电压Uk%空载电流I0SJL-1000/101373018805.51.7SJL-1600/352000030506.51.5一、各元件参数的计算及等值电路1、变压器参数（1）变压器SJL-1000/1022323200013.7310.51.5141010(%)5.510.56.0641001001.880.002%1.70.017Mvar100100kNTNkNTNNPURSUUXSPKWMWISQ（2）变压器SJL-1600/3522323220002038.511.5810101.6(%)6.538.560.2161001001.63.050.003%1.51.60.024Mvar100100kNTNkNTNNPURSUUXSPKWMWISQ1、两台变压器并联运行T000011=R11.585.79221160.21630.10822=220.0030.006220.0240.048MvarTTTRXXPPMWQQ总总总总2、架空线路参数（1）线路LGJ-50(12.5km)11R0.6512.58.1250.4212.55.25rLXxL（2）线路LGJ-35(5km)11R0.8554.250.3751.85rLXxL（3）线路LGJ-35(17km)R=r1L=0.85×17=14.45ΩX=x1L=0.37×17=6.29Ω3、发电机机组容量为3x800KW功率因数为0.8则：P=3×800=2400KW=2.4MWQ=P×tanφ=2.4×0.75=18Mvar4、等值电路29.645.14j一、假设末端电压Ud=9KV时为额定电压1、最大负荷运行方式下（1）逆推功率分布：MVAjjjXRUQpsdcdcddddc006.0013.0)29.645.14()(9257.0072.0~222222MVAjjjSSSdcdc263.0085.0006.0013.0257.0072.0~~MVAjjjsssccc609.0195.0346.011.0263.0085.0~MVAjjjxRUQPscbcbccccb009.0002.0)85.125.4()(9609.0195.0~222222'''0.220.6180.0480.171+0.002+j0.0170.270.806bbbTSSSSjjjMVA2222220.270.806()(1.5146.064)90.014+0.055bbbabababPQSRjXjUjMVA0.270.8060.0140.0550.2840.861abbaSSSjjjMVA'''0.1980.6090.0220.0090.220.618bccbSSSjjjMVA（2）正推电压分布：'10.56.310.56.30.2841.5140.8616.0640.53810.510.50.5389.962aaaTaTababaabUKUKVPRQXUKVUUUUKV''0.224.250.6181.850.2099.9629.9620.2099.753BbcBbcbcbCbbcPRQXUKVUUUUKV9.7530.3349.4199.419-9100%100%4.448%5%9.419dccddNdUUUKVUUU最大运行方式下的电压平衡率小于5%，满足要求。KVUXQRPUccdccdccd334.09.7530.263×6.290.088×45.142、最小负荷运行方式下（1）逆推功率分布：2222''''220.120.378()(4.251.85)0.0080.0049cccbcbcbcPQSRjXjjMVAU0.0450.160.0060.0020.0510.162cddcSSSjjjMVA'''0.0510.1620.0690.2160.120.378cccSSSjjjMVAMVAjjjXRUQpsdcdcddddc002.0006.0)29.645.14916.0042.0~()(222222'''0.1280.3820.030.107+0.002+j0.0170.160.506bbbYTSSSSjjjMVA2222220.160.506()(1.5146.064)90.005+0.021bbbabababPQSRjXjUjMVA0.160.5060.0050.0210.1650.527abbaSSSjjjMVA'''0.120.3780.0080.0040.1280.382bccbSSSjjjMVA（2）正推电压分布：'10.56.310.56.30.1651.5140.5276.0640.32810.510.50.32810.172aaaTaTababaabUKUKVPRQXUKVUUUUKV''0.1284.250.3821.850.12310.17210.1720.12310.049BbcBbcbcbCbbcPRQXUKVUUcUUKV10.0490.1949.8559.855-9100%100%8.68%5%9.855dccddNdUUUKVUUU最大运行方式下的电压平衡率大于5%，不满足要求。KVUXQRpUccdccdccd194.010.0490.162×6.290.051×14.45二、假设末端电压Ud=9.5KV时为额定电压1、最大负荷运行方式下（1）逆推功率分布：2222''''220.1960.608()(4.251.85)0.0190.0089.5cccbcbcbcPQSRjXjjMVAU0.0720.2570.0140.0050.0860.262cddcSSSjjjMVA'''0.0860.2620.110.3460.1960.608cccSSSjjjMVAMVAjjjXRUQpsdcdcddddc005.0014.0)29.645.145.9257.0072.0()(222222'''0.2150.6160.0480.171+0.002+j0.0170.2650.804bbbYTSSSSjjjMVA2222220.2650.804()(1.5146.064)9.50.012+0.048bbbabababPQSRjXjUjMVA0.2650.8040.0120.0480.2770.852abbaSSSjjjMVA'''0.1960.6080.0190.0080.2150.616bccbSSSjjjMVA（2）正推电压分布：'10.56.310.56.30.2771.5140.8526.0640.53210.510.50.5329.968aaaTaTababaabUKUKVPRQXUKVUUUUKV''0.2154.250.6161.850.2069.9689.9680.2069.762BbcBbcbcbCbbcPRQXUKVUUcUUKV9.7620.3299.3979.397-9.5100%100%1.098%5%9.397dccddNdUUUKVUUU最大运行方式下的电压平衡率小于5%，满足要求。KVUXQRpUccdccdccd329.09.7620.262×6.290.086×45.142、最小负荷运行方式下（1）逆推功率分布：2222''''220.120.378()(4.251.85)0.0070.0039.5cccbcbcbcPQSRjXjjMVAU0.0450.160.0060.0020.0510.162cddcSSSjjjMVA'''0.0510.1620.0690.2160.120.378cccSSSjjjMVAMVAjjjXRUQPSdcdcddddc002.0006.0)29.645.1452.916.0045.0~()(222222'''0.1270.3810.030.107+0.002+j0.0170.1590.505bbbYTSSSSjjjMVA2222220.1590.505()(1.5146.064)9.50.005+0.019bbbabababPQSRjXjUjMVA0.1590.5050.0050.0190.1640.524abbaSSSjjjMVA'''0.120.3780.0070.0030.1270.381bccbSSSjjjMVA（2）正推电压分布：'10.56.310.56.30.1641.5140.5246.0640.32610.510.50.32610.174aaaTaTababaabUKUKVPRQXUKVUUUUKV''0.1274.250.3811.850.12210.17410.1740.12210.052BbcBbcbcbCbbcPRQXUKVUUcUUKV10.0520.1949.8589.858-9.5100%100%3.63%5%9.858dccddNdUUUKVUUU最大运行方式下的电压平衡率小于5%，满足要求。KVAUXQRPUccdecdccd194.045.14