外文翻譯---基于實時頻率特性的agc方案研究

1、畢業(yè)設(shè)計（論文）專用紙第 1 頁附 錄英文原文：A Study on AGC Scheme Based on Real Time Frequency CharacteristicsHyun-Shin Park,Chungnam National University, Koreamrhspark@hanmail.netChungnam National University, Koreakjkim@cnu.ac.krAbstract-

2、 Automatic generation control (AGC) has been one of the important issues in the operation of local area and interconnected power systems. AGC provides power demand signals for AGC power generators to control frequency.

3、In AGC, some variables of power system such as frequency and power generation are measured to calculate the area control error (ACE). The ACE value is an important factor of AGC performance. Generally, ACE value is deter

4、mined by a constant frequency bias factor of power system or 1% of load method. The ACE value based on the constant frequency bias factor or1% of load method, however, may not represent the real time status of power sys

5、tem correctly. The incorrect ACE value is a cause of over regulation of power system. This paper presents the method to decide actual frequency bias factor on real time frequency characteristics. In this paper, the actu

6、al frequency bias factor is determined by the measured variables such as generator power output change and frequency deviation due to disturbance of power system. The actual frequency bias factor calculated is used to d

7、etermine the ACE of power system. The AGC divides the calculated ACE among AGC power generators periodically. The period is determined by the time of recovered frequency. This paper also presents the simulation results

8、 for the power system model about the proposed AGC scheme. The simulation results show that the performance of AGC is improved when the proposed AGC scheme is applied to AGC.I. INTRODUCTIONThe scheduling and control of

9、power generation are vital aspects in the daily operation of power systems. Generally, energy management system is provided to control the electrical power output so as to supply ever changing system load for power as

10、economically as possible. Automatic generation control (AGC) program 畢業(yè)設(shè)計（論文）專用紙第 3 頁fs : Nominal frequency B : Frequency bias factor ΔPtie : Power interchange deviationΔf :Frequency deviationFrequency bias factor, B, is

11、 determined as followsBsys ??? Req ? DReq ???（?? R1? ?? R2? ?? R3 ? ???? ?? Rn）whereR : Speed regulation parameter or DroopD : Load damping constantBsys : System frequency bias factor Req : System droopSince the objectiv

12、e of AGC is to regulate generation of units, the input of AGC should be the actual ACE. When the frequency bias of the ACE matches with the actual frequency bias of the area, the calculated ACE and the actual ACE are ide

13、ntical [3]. However, it is not practical to consider the frequency bias factor of (2) as the actual frequency bias, because the actual frequency bias is non-linearly related to the operating state of control area, i.e.,

14、 frequency, load, generation and voltage [2].For example, the speed-droop characteristic ideally ranges from 3 to 5 percent. However, the actual speed-droop characteristic may thus exhibit incremental regulation ranging

15、from 2 to 12 percent, depending on the unit output [2]. The speed-droop characteristic also depends on the type of units, such as steam unit and hydraulic unit. For example, steam turbines have a number of control valve

16、s, each having nonlinear flow area versus position characteristic [2]. The generator response is not always predictable and has time delay. Load damping characteristic, D, is the relationship between the changes in actu

17、al load due to a change in frequency. The relationship cannot be measured and varies continuously with the system status. Typical values of D are 1 to 2 percent [2]. Therefore, the fixed estimated frequency bias value

18、such as (2) is not the same as the actual frequency bias.If the estimated frequency bias is much higher than the actual frequency bias, then variations in the calculated ACE can be much larger than variations in the act

19、ual ACE. It causes often over-regulation. The AGC depends on the calculated ACE using constant frequency bias using system frequency, generator regulation and load damping as inputs. Therefore, it is critical to get ac

20、tual frequency bias value for better AGC performance.In conclusion, ACE calculation method using constant frequency bias cannot represent the actual power system status correctly.B. One-percent of load methodNorth Amer

21、ica Electric Reliability Council (NERC) offers several possible ways to calculate frequency bias. The general practice is to establish frequency bias in each control area once a year based on the area’s natural regulat