The static var compensator is now mature technology that is widely used for transmission applications. Electric utility industry standardization of basic models is needed, and is recommended in this paper. Description and model requirements for more detailed representations, including supplementary function modules, are included. In addition to transient stability program modeling, requirements for power flow and longer-term dynamics programs are given.

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Static var compensator models for power flow and dynamic performance simulation

A systematic approach to the design of a controller for superconducting magnetic energy storage (SMES) units to improve the dynamic stability of a power system is presented. The scheme employs a proportional-integral (PI) controller to enhance the damping of the electromechanical mode oscillation of synchronous generators. The parameters of the PI controller are determined by the pole assignment method based on modal control theory. Eigenvalue analysis and nonlinear computer simulations show that SMES with the PI controller can greatly improve the damping of the system under various operating conditions. Although the PI controller is designed for a special load condition, it can also provide good damping under other load conditions. >

Application of superconducting magnetic energy storage unit to improve the damping of synchronous generator

The utilization of static VAr compensators (SVC) for supplying reactive power at certain points of an electric power system is an efficient way for fast control of transient and steady-state voltage changes following short-circuits, load rejection, opening of severely loaded transmission circuits, etc. Other SVC applications include the increase of power transmission capacity through interconnections between areas of a power system and the damping enhancement of local or inter-area electromechanical oscillation modes. This paper fundamentally deals with these last two issues by analyzing the results of synchronizing and damping torque coefficient calculations for a generation station connected radially to a much larger power system. The results presented pertain to a double-circuit, 800 km, 500 kV transmission system during a one-circuit out contingency. >

Synchronizing and damping torque coefficients and power system steady-state stability as affected by static VAr compensators

This paper describes the results of a comprehensive investigation on: (1) small-signal dynamic interactions of voltage control loops of multiple static VAR compensators (SVCs); (2) the phenomena of SVC-network interactions; and (3) torsional interactions with SVCs. This paper is concerned with small-signal dynamics in the high frequency (HF) range, i.e. above 4 Hz. The studies are conducted on various power system configurations, based on the use of a newly developed eigen analysis software tool. The eigen analysis tool provides a systematic approach to include the dynamic mathematical model of the transmission network in the overall system model, which is necessary for HF dynamic studies. The investigations identify undesirable small-signal oscillations associated with SVC-SVC and/or SVC-network interactions, and provide fundamental information for design/coordination of SVCs. >

Voltage control stability and dynamic interaction phenomena of static VAr compensators

This paper presents a novel fast frequency and voltage regulation method for battery energy storage system (BESS) based on the amplitude-phase-locked-loop (APLL). In the proposed method, the primary frequency regulation and inertia emulating control are designed based on grid frequency deviation (<inline-formula> <tex-math notation="LaTeX">${\Delta }f$ </tex-math></inline-formula>) and its differential <inline-formula> <tex-math notation="LaTeX">$(df/dt)$ </tex-math></inline-formula> signals detected by APLL, avoiding complicated and sensitive differential operation to get better dynamic support performance. Moreover, unlike the traditional voltage control only using grid voltage deviation (<inline-formula> <tex-math notation="LaTeX">${\Delta }V$ </tex-math></inline-formula>), the proposed method also uses the voltage differential control (<inline-formula> <tex-math notation="LaTeX">$dV/dt$ </tex-math></inline-formula>-control) to improve dynamic performance of traditional voltage control and behaviors of grid voltage based on the <inline-formula> <tex-math notation="LaTeX">$dV/dt$ </tex-math></inline-formula> signal from APLL. Finally, simulations and experiments are implemented to validate the effectiveness of the proposed APLL-based BESS on improving the dynamic behaviors of grid frequency and voltage.

Fast Grid Frequency and Voltage Control of Battery Energy Storage System Based on the Amplitude-Phase-Locked-Loop

The authors describe the dynamic performance of a radial weak, heavily shunt-compensated power system, with three static VAr (volt-ampere reactive) compensators (SVCs) of relatively large rating installed at short distances from one another. Dynamic interactions between the SVC control systems and between them and the network are analyzed by using eigenvalues and frequency-response techniques. Some noteworthy effects concerning the SVCs' regulator stability that can arise in such systems are described. These effects, revealed in the eigenvalue analysis, were confirmed in TNA simulations. A brief description of the mathematical formulation and the complete system data is also included. Among other results, it is shown that the operation of SVCs with low values of ESCR can exhibit oscillation mode frequencies above 5 Hz, depending substantially on SVC regulator gain. In such cases, the representation of both network dynamics and thyristor time delay is crucial in the analysis if the SVC regulator stability limits. >

H. Tyll

Papers

Dynamic performance of a radial weak power system with multiple static VAr compensators