STATCOM对电力系统继电保护的影响研究综述

静止同步补偿器（STATCOM）是目前用于电力系统中性能最好的无功补偿装置。文中介绍了静止同步补偿器的基本工作原理、类型、主电路结构控制策略，从STATCOM的谐波、控制策略、安装位置和STATCOM对保护的灵敏度等四个方面综述了STATCOM应用于电力系统后对继电保护的影响的研究现状。

逼近理想解法在台区无功补偿评估中的应用

针对目前电力系统中台区无功补偿方案优劣评估大多停留在直接经济效益层面上而忽略电压特性的问题,提出采用逼近理想解法方法从电压特性及直接经济效益两个方面对无功补偿方案综合效益优劣进行评估.首先从沿线电压特性角度建立电压特性指标并建立直接经济指标;其次依据指标属性对指标进行预处理并用序关系法确定各评估指标的权重;然后获取各指标的正向理想解和负向理想解,并采用改进相近度法计算各无功补偿方案与理想解的相对接近度,从而得出无功补偿方案综合效益优劣排序结果。最后采用文中方法对实际台区5种无功补偿方案优劣进行评估,并且与只考虑直接经济效益的优劣排序结果对比,验证文中方法的客观性和有效性.

高压电容器室运行环境治理

高压电容器作为电力系统无功补偿核心设备,其可靠运行对电网安全运行影响重大。考虑变电站集约化的需求,室内电容器占比较高;但在对高压电容器室日常运维过程中发现,室内普遍存在散热较差的情况。为解决实际运维过程中高压电容器室温升超限导致的设备故障问题,本课题对高压电容器室内热量积聚的原因进行了研究分析,并针对过热原因提出了电容器室环境治理方案。

Enhancement of Real Power Transfer Capability of Transmission Lines

As power system interconnections become more prevalent, there has been an increase in use of thyristor controlled shunt connected compensation devices for dynamic power compensation and enhancement of real power transmission capacity. In this paper, an enhancement technique of real power transfer capacity of transmission lines is presented. A SVC （static var compensator） is designed and applied to a simple power system for this purpose. Increase in power flow and improvement in bus voltage profile are observed after using the SVC. Stability analysis of the system after experiencing fault as well as consequent fault clearance by time domain analysis has also beeu performed and satisfactory results are obtained.

Stability Improvement of Power System by Using PI ＆ PD Controller

This paper presents the model of a SVC （Static VAR Compensator） which is controlled externally by a PI （Proportional Integral） ＆ PD （Proportional Differential） controllers for the improvements of voltage stability and damping effect of an on line power system. Both controller parameters has been optimized by using Ziegler-Nichols close loop tuning method. Both single phase and three phase （L-L） faults have been considered in the research. In this paper, a power system network is considered which is simulated in the phasor simulation method ＆ the network is simulated in four steps; without SVC, With SVC but no externally controlled, SVC with PI controller ＆ SVC with PD controller. Simulation result shows that without SVC, the system parameters become unstable during faults. When SVC is imposed in the network, then system parameters become stable. Again, when SVC is controlled externally by PI ＆ PD controllers, then system parameters becomes stable in faster way then without controller. It has been observed that the SVC ratings are only 50 MVA with controllers and 200 MVA without controllers. So, SVC with PI ＆ PD controllers are more effective to enhance the voltage stability and increases power transmission capacity of a power system. The power system oscillations are also reduced with controllers in compared to that of without controllers. So with both controllers the system performance is greatly enhanced.

Potential Solution of Power Flow Constraints of Bangladesh Power System

This paper presents a potential solution of power flow constraints of BPS （Bangladesh power system） using VAR （volt ampere reactive） compensation. VAR compensation is defined as the management of reactive power to improve the performance ofac power systems. The concept of VAR compensation embraces a wide and diverse field of both system and customer problems, especially related with power quality issues, since most of power quality problems can be attenuated or solved with an adequate control of reactive power. VAR compensation in transmission systems also improves the stability of the ac system by increasing the maximum active power that can be transmitted. It also helps to maintain a substantially fiat voltage profile at all levels of power transmission. BPS is currently facing problems in few 132 grid points where the thermal limits of transmission are often exceeded. BPS is also foreseeing problem in transmitting additional power from the new generating units in Sylhet to Dhaka zone. This paper investigates the potential solution to these transmission problems.

Coordination of Synergetic Excitation Controller and SVC Damping Controller Using Particle Swarm Optimization

This paper addresses the enhancement of power system stability by simultaneous tuning of synergetic excitation damping controller and SVC （static var compensator）-based damping controllers. Each machine or generator is considered as a subsystem and its interaction with the remaining part of the system, the SVC inclusive, is modeled as a quadratic function of the active power delivered by the generator. Stable manifold is constructed for each excitation controller and based on that, an effective damping controller is derived. A lead-lag compensator is employed as a supplementary controller for the SVC. PSO （particle swarm optimization） algorithm is effectively utilized to simultaneously tune the parameters for the excitation damping controller（s） and the SVC supplementary controller. The coordination of the controllers effectively dampens the power angle oscillation and regulates the generator terminal voltage when a fault occurs. Simulation results are obtained by using the PAT （power analysis toolbox） for a SMIB （single machine infinite bus） system and a two area power system.