测试大型汽轮发电机组轴系扭振模态的扫频法
技术领域
本发明涉及电力系统、大型火力发电厂,需要汽轮发电机组或大容量电动机的工业领域
背景技术
大型火力汽轮机组技术是我国重大装备的关键设备之一,发电厂的大规模建设是我国工业快速发展的保障。大功率机组的轴系具有轻质柔性、多支承、大跨距、高功率密度的特征,发电机材料利用系数提高,轴系截面功率密度相对增大,轴系的加长使扭转刚度下降,轴系固有频率谱相对较密,诱发振动的能量较低;同时电网也在朝着超高压大区域的方向发展,超高压远距离输电大量采用串补电容提高电网输电能力,以及新型采用电力电子元件的输配电和控制技术的应用,所有这些都使诱发机组振动的潜在因素日益增加,使机组轴系扭振问题越来越严重。另一方面,扭振也会激发电网的振荡,造成线路跳闸或机组解列,直接影响到系统的稳定运行和大量用户的经济利益。
如何准确测试现场安装后的大型汽轮发电机组的轴系机械扭振模态是保护机组轴系的关键。目前国内测试该项内容的方法是大型发电机运行起来后做多种扰动试验,包括机组同期、解列、线路投切、机组甩负荷等,不能保证试验每次是充分有效的,且对机组和电网运行有一定的破坏性。本发明涉及一种可控的测试大型汽轮发电机组轴系模态的扫频法,通过专门的试验装置和控制软件与被测试机组接口,通过对发电机组励磁系统注入可调节小控制信号,在机组轴系产生控制力矩,进而测试机组轴系的频率相应,并最终确定轴系的模态。
发明内容
研究了检测汽轮发电机组轴系扭振模态的扫频法,开发了大型汽轮发电机组轴系扭振控制器的软硬件和扭振测试仪,结合系统的测试方法,可实现对发电机组连续变频率的扭振力矩扫描,同时测试轴系的扭振响应,进而得到轴系的扭振模态。
本发明适用于1000MW、600MW、300MW的主力大型汽轮发电机组,也同样适用于300MW以下的小型汽轮发电机组和大容量电动机。
扫频法测试汽轮发电机组轴系扭振模态的检测方法的具体步骤:
通过装置发出4~20mA正弦电流信号,转换为2~10V的电压信号作为激励信号注入发电机励磁系统,在励磁系统的电流、电压中产生和注入的激励信号频率相同的信号;
励磁系统随发电机组转子旋转,在发电机组轴系产生与注入信号频率相同的电磁扭矩;
连续调节注入正弦信号的频率,调节范围为2~48Hz,步长为0.1Hz,发电机组轴系随注入激励信号的频率变化,产生2~48Hz的电气扭矩,扭矩作用在轴系产生扭振;
实时测量发电机组机端转速传感器信号,实时计算并监视激励信号在轴系产生的扭振的强度;
在某个频率点附件,实时测量的扭振强度达到局部极大值,则判断这个频率点是发电机组轴系的一个扭振模态;
在扭振模态频率值附近缓慢改变注入信号频率,反复试验得到精确的扭振模态,精度精确到0.1Hz。
本发明给出了一种测量大型汽轮发电机组轴系扭振模态的试验方法。该方法能够非常可靠、准确实际测量大型汽轮发电机组的轴系扭振模态。随着大容量汽轮发电机组和远距离大容量输电技术的应用,在机组和电网中发生次同步振荡(SSO)的情况越来越严重,测试机组轴系扭振模态是解决SSO问题的根本,是抑制次同步振荡、保护发电机组等电力设备的运行安全的基础,本方法相对于现有的通过大型发电机组人工并解列、甩负荷、人工接地等试验手段相比具有准确、经济、可重复等突出优点。对解决发电厂和电网的次同步振荡问题具有重大意义。
附图说明
图1示意了测量机组轴系扭振响应的装置(CSC-812T)的具体接线;
图2示意了CSC-812T装置的输出接线;
图3示意了提供机组轴系扭振力矩的扭振激发装置(CSC-811T)的具体接线;
图4示意了CSC-811T装置将扫频控制信号注入励磁系统的接口;
图5示意了扫频法试验的输入频率与输出响应的关系。
具体实施方式
通过研究检测汽轮发电机组轴系扭振模态的扫频法,开发了大型汽轮发电机组轴系扭振控制器的软硬件和扭振测试仪,结合系统的测试方法,可实现对发电机组连续变频率的扭振力矩扫描,同时测试轴系的扭振响应,进而得到轴系的扭振模态。
图1示意了测量机组轴系扭振响应的装置(CSC-812T)的具体接线。其中图的上部分示意了机组的汽轮机高压缸(HP)、中压缸(IP)、低压缸(LP)和发电机(GEN)。从高压缸的首端安装一对轴系的转速传感器。装置采集轴系冗余的转速传感器发出转速信号,计算轴系转速变化率dW。CSC-812T装置通过以太网与HMI相连,试验人员通过HMI记录试验过程并显示试验结果。
图2示意了CSC-812T装置的输出接线。CSC-812T装置在试验过程中可以输出D0和A0信号,其中D0信号表示dW信号出现,并超过设定门槛值;A0信号将dW信号实时输出到端子上,可外接示波器显示dW信号的波形。
图3示意了提供机组轴系扭振力矩的扭振激发装置(CSC-811T)的具体接线。通过HMI软件与扭振激发装置CSC-811T通信,扭振激发装置按照扫描频率变化,输出恒定幅值(励磁满输出的60%)的单一频率控制信号(4~20mA电流信号),接入发电机组的励磁控制器(AVR),AVR自动将CSC-811T的控制信号调制在励磁系统的输出上,进而通过励磁系统在发电机转子中建立与输入激励信号相同频率的磁场,该磁场对发电机轴系产生电磁扭矩,从而激发发电机组发生轻微的扭振。
励磁控制器(AVR)是发电机励磁系统的控制装置,其作用是通过励磁系统在发电机转子中产生励磁电流,建立旋转磁场,从而使发电机定子中产生工频电流,实现机械能与电能的转换。本试验方法在励磁控制器(AVR)的输入端叠加了一个可控频率的控制信号Usedc,通过励磁产生一个特殊的磁场,从而激发特殊频率的扭振。
图4示意了CSC-811T装置将扫频控制信号注入励磁系统的接口。其中CSC-811T装置输出控制4~20mA的电流信号,经电阻变为电压信号(Usedc),接入励磁控制器(AVR)装置,AVR采集该控制信号,叠加在AVR的控制输出中,输出Uc信号,Uc经励磁系统内部的触发、整流,在励磁电压(Uf)、励磁电流(If)中调制出与输入Usedc相同频率的信号,最终作用在发电机组产生与CSC-811T装置注入频率相同的扭矩。
按照图1、图2、图3、图4在试验机组上接线;注意转速传感器的安装和信号线屏蔽。CSC-811T和CSC-812T与HMI相连接。HMI同时监控CSC-811T和CSC-812T;
扫频法测试汽轮发电机组轴系扭振模态的检测方法的具体步骤如下:
1、通过CSC-811T装置产生可控的模态激励信号
通过上位机HMI软件可设置CSC-811T装置输出频率可变、幅值可变的正弦信号;
频率变化从2Hz按照0.1Hz步长增长到48Hz,每个步长持续时间为10S;
对应每个频点,输出的模态信号为最大4~20mA电流信号,经外接500欧姆电阻转换为2~10V电压信号,其中2V对应励磁的负向顶值输出,10V对应励磁的正向顶值输出;
测试过程输出信号按在励磁输出范围的60%输出,即输出3.6V~8.4V;
输出信号可通过控制软件取消或闭锁。
2、通过CSC-812T装置实时测量汽轮发电机组轴系扭振响应
CSC-812T通过安装在轴系的转速传感器实时采集计算轴系的dW(转速变化率)大小;
在HMI上可自动记录并显示dW的大小及其变化趋势。
3、自动记录激励信号与响应的轴系响应信号的曲线
HMI软件自动记录输出的激励信号频率和强度、采集的轴系响应信号的模态强度,生产激励响应曲线;
识别曲线中的局部极大值,局部极大值所对应的频率是机组轴系的模态;
机组模态数量通常为3~5个。
以国内某电厂600MW汽轮发电机组(目前国内的主力发电机组容量为600MW)为例,按照上述图1~图4完成试验接线,CSC-811T装置依次间隔0.1Hz输出2Hz、2.1Hz、2.2Hz…48Hz的控制信号,各持续10S。CSC-812T装置通过位于汽轮发电机组机端的转速传感器测量该激励下的响应输出dw的幅值。试验记录数据如表1,图5给出了该试验中输入信号的频率和输入响应幅值的关系,从中可以识别出该机组轴系的3个固有模态:15.1Hz、20.6Hz、30.5Hz。
表1:某600MW机组扫频法试验数据
输入信号频率(Hz) |
输入信号强度(满输出的百分比) |
响应信号强度dw(弧度/s) |
2 |
60% |
0 |
2.1 |
60% |
0 |
2.2 |
60% |
0 |
2.3 |
60% |
0 |
2.4 |
60% |
0 |
2.5 |
60% |
0 |
2.6 |
60% |
0 |
2.7 |
60% |
0 |
2.8 |
60% |
0 |
2.9 |
60% |
0 |
3.0 |
60% |
0 |
2.1 |
60% |
0 |
2.2 |
60% |
0 |
2.3 |
60% |
0 |
2.4 |
60% |
0 |
2.5 |
60% |
0 |
2.6 |
60% |
0 |
2.7 |
60% |
0 |
2.8 |
60% |
0 |
2.9 |
60% |
0 |
3.0 |
60% |
0 |
2.6 |
60% |
0 |
3.1 |
60% |
0 |
3.2 |
60% |
0 |
3.3 |
60% |
0 |
3.4 |
60% |
0 |
3.5 |
60% |
0 |
3.6 |
60% |
0 |
3.7 |
60% |
0 |
3.8 |
60% |
0 |
3.9 |
60% |
0 |
4.0 |
60% |
0 |
4.1 |
60% |
0 |
4.2 |
60% |
0 |
4.3 |
60% |
0 |
4.4 |
60% |
0 |
4.5 |
60% |
0 |
4.6 |
60% |
0 |
4.7 |
60% |
0 |
4.8 |
60% |
0 |
4.9 |
60% |
0 |
5.0 |
60% |
0 |
5.1 |
60% |
0 |
5.2 |
60% |
0 |
2.6 |
60% |
0 |
5.3 |
60% |
0 |
5.4 |
60% |
0 |
5.5 |
60% |
0 |
5.6 |
60% |
0 |
5.7 |
60% |
0 |
5.8 |
60% |
0 |
5.9 |
60% |
0 |
6.0 |
60% |
0 |
6.1 |
60% |
0 |
6.2 |
60% |
0 |
6.3 |
60% |
0 |
6.4 |
60% |
0 |
6.5 |
60% |
0 |
6.6 |
60% |
0 |
6.7 |
60% |
0 |
6.8 |
60% |
0 |
6.9 |
60% |
0 |
7.0 |
60% |
0 |
7.1 |
60% |
0 |
7.2 |
60% |
0 |
7.3 |
60% |
0 |
7.4 |
60% |
0 |
2.6 |
60% |
0 |
7.5 |
60% |
0 |
7.6 |
60% |
0 |
7.7 |
60% |
0 |
7.8 |
60% |
0 |
7.9 |
60% |
0 |
8.0 |
60% |
0 |
8.1 |
60% |
0 |
8.2 |
60% |
0 |
8.3 |
60% |
0 |
8.4 |
60% |
0 |
8.5 |
60% |
0 |
8.6 |
60% |
0 |
8.7 |
60% |
0 |
8.8 |
60% |
0 |
8.9 |
60% |
0 |
9.0 |
60% |
0 |
9.1 |
60% |
0 |
9.2 |
60% |
0 |
9.3 |
60% |
0 |
9.4 |
60% |
0 |
9.5 |
60% |
0 |
9.6 |
60% |
0 |
8.4 |
60% |
0 |
9.7 |
60% |
0 |
9.8 |
60% |
0 |
9.9 |
60% |
0 |
10.0 |
60% |
0 |
10.1 |
60% |
0 |
10.2 |
60% |
0 |
10.3 |
60% |
0 |
10.4 |
60% |
0 |
10.5 |
60% |
0 |
10.6 |
60% |
0 |
10.7 |
60% |
0 |
10.8 |
60% |
0 |
10.9 |
60% |
0 |
11.0 |
60% |
0 |
11.1 |
60% |
0 |
11.2 |
60% |
0 |
11.3 |
60% |
0 |
11.4 |
60% |
0 |
11.5 |
60% |
0 |
11.6 |
60% |
0 |
11.7 |
60% |
0 |
11.8 |
60% |
0 |
8.4 |
60% |
0 |
11.9 |
60% |
0 |
12.0 |
60% |
0 |
12.1 |
60% |
0 |
12.2 |
60% |
0 |
12.3 |
60% |
0 |
12.4 |
60% |
0 |
12.5 |
60% |
0 |
12.6 |
60% |
0 |
12.7 |
60% |
0 |
12.8 |
60% |
0 |
12.9 |
60% |
0 |
13.0 |
60% |
0 |
13.1 |
60% |
0 |
13.2 |
60% |
0 |
13.3 |
60% |
0 |
13.4 |
60% |
0 |
13.5 |
60% |
0 |
13.6 |
60% |
0 |
13.7 |
60% |
0 |
13.8 |
60% |
0 |
13.9 |
60% |
0 |
14.0 |
60% |
0 |
14.2 |
60% |
0 |
14.3 |
60% |
0 |
14.4 |
60% |
0.01 |
14.5 |
60% |
0.03 |
14.6 |
60% |
0.06 |
14.7 |
60% |
0.11 |
14.8 |
60% |
0.24 |
14.9 |
60% |
0.43 |
15.0 |
60% |
0.83 |
15.1 |
60% |
1.24 |
15.2 |
60% |
1.05 |
15.3 |
60% |
0.62 |
15.4 |
60% |
0.21 |
15.5 |
60% |
0.10 |
15.6 |
60% |
0.04 |
15.7 |
60% |
0.01 |
15.8 |
60% |
0 |
15.9 |
60% |
0 |
16.0 |
60% |
0 |
16.1 |
60% |
0 |
16.2 |
60% |
0 |
14.2 |
60% |
0 |
16.3 |
60% |
0 |
16.4 |
60% |
0 |
16.5 |
60% |
0 |
16.6 |
60% |
0 |
16.7 |
60% |
0 |
16.8 |
60% |
0 |
16.9 |
60% |
0 |
17.0 |
60% |
0 |
17.1 |
60% |
0 |
17.2 |
60% |
0 |
17.3 |
60% |
0 |
17.4 |
60% |
0 |
17.5 |
60% |
0 |
17.6 |
60% |
0 |
17.7 |
60% |
0 |
17.8 |
60% |
0 |
17.9 |
60% |
0 |
18.0 |
60% |
0 |
18.1 |
60% |
0 |
18.2 |
60% |
0 |
18.3 |
60% |
0 |
18.4 |
60% |
0 |
14.2 |
60% |
0 |
18.5 |
60% |
0 |
18.6 |
60% |
0 |
18.7 |
60% |
0 |
18.8 |
60% |
0 |
18.9 |
60% |
0 |
19.0 |
60% |
0 |
20.1 |
60% |
0 |
20.2 |
60% |
0 |
20.3 |
60% |
0 |
20.4 |
60% |
0 |
20.5 |
60% |
0 |
20.6 |
60% |
0 |
20.7 |
60% |
0 |
20.8 |
60% |
0 |
20.9 |
60% |
0 |
21.0 |
60% |
0 |
21.1 |
60% |
0 |
21.2 |
60% |
0 |
21.3 |
60% |
0 |
21.4 |
60% |
0 |
21.5 |
60% |
0 |
21.6 |
60% |
0 |
21.0 |
60% |
0 |
21.7 |
60% |
0 |
21.8 |
60% |
0 |
21.9 |
60% |
0 |
22.0 |
60% |
0 |
22.1 |
60% |
0 |
22.2 |
60% |
0 |
22.3 |
60% |
0 |
22.4 |
60% |
0 |
22.5 |
60% |
0 |
22.6 |
60% |
0 |
22.7 |
60% |
0 |
22.8 |
60% |
0 |
22.9 |
60% |
0 |
23.0 |
60% |
0 |
23.1 |
60% |
0 |
23.2 |
60% |
0 |
23.3 |
60% |
0 |
23.4 |
60% |
0 |
23.5 |
60% |
0 |
23.6 |
60% |
0 |
23.7 |
60% |
0 |
23.8 |
60% |
0 |
21.0 |
60% |
0 |
23.9 |
60% |
0 |
24.0 |
60% |
0 |
24.1 |
60% |
0 |
24.2 |
60% |
0 |
24.3 |
60% |
0 |
24.4 |
60% |
0 |
24.5 |
60% |
0 |
24.6 |
60% |
0 |
24.7 |
60% |
0 |
24.8 |
60% |
0 |
24.9 |
60% |
0 |
25.0 |
60% |
0 |
25.1 |
60% |
0 |
25.2 |
60% |
0 |
25.3 |
60% |
0 |
25.4 |
60% |
0.02 |
25.5 |
60% |
0.05 |
25.6 |
60% |
0.13 |
25.7 |
60% |
0.30 |
25.8 |
60% |
0.56 |
25.9 |
60% |
1.03 |
26.0 |
60% |
1.66 |
21.0 |
60% |
0 |
26.1 |
60% |
1.97 |
26.2 |
60% |
1.20 |
26.3 |
60% |
0.67 |
26.4 |
60% |
0.41 |
26.5 |
60% |
0.17 |
26.6 |
60% |
0.06 |
26.7 |
60% |
0.03 |
26.8 |
60% |
0.01 |
26.9 |
60% |
0 |
27.0 |
60% |
0 |
27.1 |
60% |
0 |
27.2 |
60% |
0 |
27.3 |
60% |
0 |
27.4 |
60% |
0 |
27.5 |
60% |
0 |
27.6 |
60% |
0 |
27.7 |
60% |
0 |
27.8 |
60% |
0 |
27.9 |
60% |
0 |
28.0 |
60% |
0 |
28.1 |
60% |
0 |
28.2 |
60% |
0 |
26.8 |
60% |
0.01 |
28.3 |
60% |
0 |
28.4 |
60% |
0 |
28.5 |
60% |
0 |
28.6 |
60% |
0 |
28.7 |
60% |
0 |
28.8 |
60% |
0 |
28.9 |
60% |
0 |
29.0 |
60% |
0 |
29.1 |
60% |
0 |
29.2 |
60% |
0 |
29.3 |
60% |
0 |
29.4 |
60% |
0 |
29.5 |
60% |
0 |
29.6 |
60% |
0 |
29.7 |
60% |
0.01 |
29.8 |
60% |
0.04 |
29.9 |
60% |
0.07 |
30.0 |
60% |
0.21 |
30.1 |
60% |
0.34 |
30.2 |
60% |
0.82 |
30.3 |
60% |
1.45 |
30.4 |
60% |
2.12 |
26.8 |
60% |
0.01 |
30.5 |
60% |
2.46 |
30.6 |
60% |
2.27 |
30.7 |
60% |
1.32 |
30.8 |
60% |
0.71 |
30.9 |
60% |
0.34 |
31.0 |
60% |
0.16 |
31.1 |
60% |
0.09 |
31.2 |
60% |
0.04 |
31.3 |
60% |
0.02 |
31.4 |
60% |
0 |
31.5 |
60% |
0 |
31.6 |
60% |
0 |
31.7 |
60% |
0 |
31.8 |
60% |
0 |
31.9 |
60% |
0 |
32.0 |
60% |
0 |
32.1 |
60% |
0 |
32.2 |
60% |
0 |
32.3 |
60% |
0 |
32.4 |
60% |
0 |
32.5 |
60% |
0 |
32.6 |
60% |
0 |
32.7 |
60% |
0 |
32.8 |
60% |
0 |
32.9 |
60% |
0 |
33.0 |
60% |
0 |
33.1 |
60% |
0 |
33.2 |
60% |
0 |
33.3 |
60% |
0 |
33.4 |
60% |
0 |
33.5 |
60% |
0 |
33.6 |
60% |
0 |
33.7 |
60% |
0 |
33.8 |
60% |
0 |
33.9 |
60% |
0 |
34.0 |
60% |
0 |
34.1 |
60% |
0 |
34.2 |
60% |
0 |
34.3 |
60% |
0 |
34.4 |
60% |
0 |
34.5 |
60% |
0 |
34.6 |
60% |
0 |
34.7 |
60% |
0 |
34.8 |
60% |
0 |
32.6 |
60% |
0 |
34.9 |
60% |
0 |
35.0 |
60% |
0 |
35.1 |
60% |
0 |
35.2 |
60% |
0 |
35.3 |
60% |
0 |
35.4 |
60% |
0 |
35.5 |
60% |
0 |
35.6 |
60% |
0 |
35.7 |
60% |
0 |
35.8 |
60% |
0 |
35.9 |
60% |
0 |
36.0 |
60% |
0 |
36.1 |
60% |
0 |
36.2 |
60% |
0 |
36.3 |
60% |
0 |
36.4 |
60% |
0 |
36.5 |
60% |
0 |
36.6 |
60% |
0 |
36.7 |
60% |
0 |
36.8 |
60% |
0 |
36.9 |
60% |
0 |
37.0 |
60% |
0 |
32.6 |
60% |
0 |
37.1 |
60% |
0 |
37.2 |
60% |
0 |
37.3 |
60% |
0 |
37.4 |
60% |
0 |
37.5 |
60% |
0 |
37.6 |
60% |
0 |
37.7 |
60% |
0 |
37.8 |
60% |
0 |
37.9 |
60% |
0 |
38.0 |
60% |
0 |
38.1 |
60% |
0 |
38.2 |
60% |
0 |
38.3 |
60% |
0 |
38.4 |
60% |
0 |
38.5 |
60% |
0 |
38.6 |
60% |
0 |
38.7 |
60% |
0 |
38.8 |
60% |
0 |
38.9 |
60% |
0 |
39.0 |
60% |
0 |
39.1 |
60% |
0 |
39.2 |
60% |
0 |
38.4 |
60% |
0 |
39.3 |
60% |
0 |
39.4 |
60% |
0 |
39.5 |
60% |
0 |
39.6 |
60% |
0 |
39.7 |
60% |
0 |
39.8 |
60% |
0 |
39.9 |
60% |
0 |
40.0 |
60% |
0 |
40.1 |
60% |
0 |
40.2 |
60% |
0 |
40.3 |
60% |
0 |
40.4 |
60% |
0 |
40.5 |
60% |
0 |
40.6 |
60% |
0 |
40.7 |
60% |
0 |
40.8 |
60% |
0 |
40.9 |
60% |
0 |
41.0 |
60% |
0 |
41.1 |
60% |
0 |
41.2 |
60% |
0 |
41.3 |
60% |
0 |
41.4 |
60% |
0 |
38.4 |
60% |
0 |
41.5 |
60% |
0 |
41.6 |
60% |
0 |
41.7 |
60% |
0 |
41.8 |
60% |
0 |
41.9 |
60% |
0 |
42.0 |
60% |
0 |
42.1 |
60% |
0 |
42.2 |
60% |
0 |
42.3 |
60% |
0 |
42.4 |
60% |
0 |
42.5 |
60% |
0 |
42.6 |
60% |
0 |
42.7 |
60% |
0 |
42.8 |
60% |
0 |
42.9 |
60% |
0 |
43.0 |
60% |
0 |
43.1 |
60% |
0 |
43.2 |
60% |
0 |
43.3 |
60% |
0 |
43.4 |
60% |
0 |
43.5 |
60% |
0 |
43.6 |
60% |
0 |
38.4 |
60% |
0 |
43.7 |
60% |
0 |
43.8 |
60% |
0 |
43.9 |
60% |
0 |
44.0 |
60% |
0 |
44.1 |
60% |
0 |
44.2 |
60% |
0 |
44.3 |
60% |
0 |
44.4 |
60% |
0 |
44.5 |
60% |
0 |
44.6 |
60% |
0 |
44.7 |
60% |
0 |
44.8 |
60% |
0 |
44.9 |
60% |
0 |
45.0 |
60% |
0 |
45.1 |
60% |
0 |
45.2 |
60% |
0 |
45.3 |
60% |
0 |
45.4 |
60% |
0 |
45.5 |
60% |
0 |
45.6 |
60% |
0 |
45.7 |
60% |
0 |
45.8 |
60% |
0 |
44.2 |
60% |
0 |
45.9 |
60% |
0 |
46.0 |
60% |
0 |
46.1 |
60% |
0 |
46.2 |
60% |
0 |
46.3 |
60% |
0 |
46.4 |
60% |
0 |
46.5 |
60% |
0 |
46.6 |
60% |
0 |
46.7 |
60% |
0 |
46.8 |
60% |
0 |
46.9 |
60% |
0 |
47.0 |
60% |
0 |
47.1 |
60% |
0 |
47.2 |
60% |
0 |
47.3 |
60% |
0 |
47.4 |
60% |
0 |
47.5 |
60% |
0 |
47.6 |
60% |
0 |
47.7 |
60% |
0 |
47.8 |
60% |
0 |
47.9 |
60% |
0 |
48.0 |
60% |
0 |