無功補(bǔ)償畢業(yè)設(shè)計(jì)外文翻譯--在解除管制的環(huán)境下功率和電壓控制的定價(jià)問題

1、文獻(xiàn)翻譯 文獻(xiàn)翻譯英文原文： 英文原文：Issues for reactive power and voltage control pricing in aderegulated environmentAbstractIssues related to reactive power, voltage support and transmission losses as dictated from a certain class of e

2、lectric loads are addressed. Specifically, the impact of predominantly induction motor loads on voltage support, reactive power requirements, and transmission losses is examined. These issues are examined with a model,

3、 which explicitly models the induction motor mechanical load. Simulation results on a simplified electric power system are presented. Based on these results, a pricing structure for voltage and reactive power support is

4、proposed. The basic assumption of the paper is that, in a deregulated environment, the expense of the incremental requirements for voltage control should be charged to the member causing the additional requirements. Th

5、e results of this work can also be used to justify long-term pricing agreements between suppliers and customers. Keywords: Reactive power; Induction motor loads; Voltage support; Reactive power pricing 1. IntroductionVol

6、tage control in an electric power system is important for many reasons: _a. all end-use equipmentneed near-nominal voltage for their proper operation, _b. near-nominal voltage results in near- minimum transmission losses

7、, and _c. near-nominal voltages increase the ability of the system to with-stand disturbances _security.. A reasonable voltage profile throughout an electric power system is associated with the ability of the system to

8、transfer power from one location to another. When the voltage sags to low values, this ability of the system is compromised. The onset of power transfer inability can be detected with sensitivity analysis of reactive p

9、ower requirements vs. real power load increases. This sensitivity is dependent on the characteristics of the electric load. Such sensitivity analyses have been performed using various electric load models, i.e. constant

10、 power load, constant impedance load, or combination of the two _voltage-dependent load. The majority of electric loads are induction motors. These loads do not fit into any of the load model categories mentioned. Yet,

11、 they drastically affect the stability of the electric power system. In this paper, we assert the need to model induction motor loads within the power flow formulation and directly evaluate the effects of such loads on

12、reactive power requirements. It is shown that the power flow formulation can be augmented to include the specific induction motor loads. Interesting nonlinear phenomena occur when the voltage at induction motor loads s

13、ags to low values. These phenomena affect the performance of the transmission system. In a deregulated environment, it makes sense to examine these phenomena and design a pricing model based on the reactive power to rat

14、ed load is 1.0, i.e. any additional 1 MW of load will require 1 MVA of generated reactive power. When the induction motor load becomes 1.0 p.u., the sensitivity becomes 1.58 MVA /MW. Similarly, the transmission loss sen

15、sitivity with respect to load increases drastically as the induction motor load reaches 1.0 p.u. For example, when the load is 1.0 p.u., the incremental losses become 4%, a relatively high value.Figs. 4–6 illustrate th

16、at at the point before the voltage collapse, the sensitivities become very high. Specifically, the voltage sensitivity is y1.0, the reactive power sensitivity is 3.8 MVA rMW and the transmission loss sensitivity is 0.094

17、. This data can be used in two ways. First, application of limits on system sensitivities will ensure that the system never operates near the point of voltage collapse. Second, the sensitivities can provide the basis fo

18、r setting tariffs for voltage support and reactive power of predominantly induction motor loads. The basis of the tariff structure and its implementation is discussed in Section 5. One can argue that these tariffs may b

19、e applied to all loads for simplicity.The results in Figs. 3–6 were obtained for a specific system. The same information can be obtained for any system using the proposed model. Then this information can be utilized to i

20、mpose tariffs for loads that are predominantly induction motors.5. Tariff structureThe basis of the tariff structure is the cost of providing voltage and reactive power support subject to acceptable system performance. A

21、cceptable system performance can be established by imposing limits to the sensitivities of voltage magnitude and reactive power requirements. These limits are system dependent and should be decided upon extensive studie

22、s of the system. The same studies will providethe range of sensitivities of voltage magnitude, reactive power requirements and transmission losses. Adirect cost can be associated with the transmission losses. An investme

23、nt cost can also be associatedwith reactive power requirements. Let x be the average transmission loss sensitivity and z be the maximum reactive power sensitivity. Then the cost of providing these services is:C=p1 x+p2

24、 z， where p1 is the price of electric energy, and p2 is the investment cost of reactive power sources.Note that the investment cost must be computed on the basis of the maximum requirements throughout the study period.

25、 The cost C provides the basis for establishing the actual tariffs. It is also important to note that, today, technology exists to monitor the impact of a specific load on the system resources. Using this technology, o

26、ne can monitor the voltage magnitude, reactive power and most importantly the sensitivities of voltage magnitude, reactive power requirements, and transmission losses. It is conceivable that pricing can be performed in