The Study On SVC Response Time And Its Impact On Vltage Stability

With the development national economy, more and more asynchronous motors, transformers and other equipments as shock loads which spend a lot of reactive power are on distribution grid. The increasing number of long-distance transmission lines in the transmission grid which make the system voltage lower and less dynamic reactive power. So the focus of power system studies is how to ensure the quality of power, the grid security and reliability.The most effective measures to compensate the reactive power consumed by loads in the distribution grid and to improve transmission capacity and stability in the transmission grid is to parallel reactive power compensation devices. Static Var Compensator (SVC) is currently one of the most widely used reactive power com-pensation device. The characteristic response time is one of the important features about SVC reactive power compensation capacity in the various characteristics of the SVC. But few researches of SVC response time characteristics in various studies.Based on the status of less researches of SVC response time, this paper has studied the characteristics of SVC response time. Establish a SVC system-level con-trollable current source model which is based on the characteristics of SVC response time. This paper analyzed the simulations of SVC physical model and SVC sys-tem-level controlled current source mode to get their reactive power compensation capacity respectively.Through the load and system compensation capacity simulations by software PSCAD and BPA respectively, this paper could get the results which are as follows: the SVC physical model and the controlled current source model had same response time, the controlled current model's compensation capability is similar to the SVC physical model in the load compensation and better than SVC physical in the system compensation.