Advanced Digital Power System Simulator Research Articles

Modeling and fault diagnosis of distribution networks cyber physical system based on IEC61850

In order to improve the fault tolerance and solution efficiency of power grid fault diagnosis model, a distribution network cyber physical system (CPS) fault diagnosis model based on advanced digital power system simulator (ADPSS) and IEC61850 is proposed. Firstly, the action rules and action status of CPS fault mode of distribution network from the whole correlation of fault element, protection action and circuit breaker trip, and the CPS grid topology of distribution network is constructed in ADPSS based on the topology and component characteristics of system. Secondly, according to the IEC61850 unified information model and modeling rules for the protection function of system equipment and operation function of circuit breaker, an information model with alarm, measurement, protection and fault recording logic is established. Then, the action status is obtained and used for the establishment of the distribution network fault diagnosis model by parsing the GOOSE message. Finally, the proposed modeling method and fault diagnosis strategy is validated through the test case.

Digital/analog hybrid simulation platform of distributed power flow controller based on ADPSS and dSPACE

Distributed power flow controller, which is among the most powerful distributed flexible transmission equipments, is still only in the stage of the theoretical research and digital simulation. In order to promote the engineering demonstration of a distributed power flow controller, it is urgent to establish a digital/analog simulation platform that supports closed-loop real-time simulation of a distributed power flow controller. In this paper, the electromagnetic transient model of a distributed power flow controller is established on ADPSS (advanced digital power system simulator). The rapid control prototype realized by dSPACE is connected to ADPSS to form a digital/analog simulation platform for a distributed power flow controller. Through a voltage control and power flow control simulation of the test system with a distributed power flow controller, the correctness and effectiveness of the constructed simulation platform are verified, which provides a new way for the verification of the new theory of a distributed power flow controller.

Influence Factors of Stability on Offshore HVDC Transmission Systems

Sun, L.; Liu, H., and Bian, D., 2019. Influence factors of stability on offshore HVDC transmission systems. In: Guido-Aldana, P.A. and Mulahasan, S. (eds.), Advances in Water Resources and Exploration. Journal of Coastal Research, Special Issue No. 93, pp. 561–571. Coconut Creek (Florida), ISSN 0749-0208.Offshore wind energy has been recognized as one of the most promising renewable energy resources available. High-voltage direct current (HVDC) appears to be the most viable option for solving the transmission of the large amount of energy over long distances of the integration of offshore wind farms. However, HVDC with large capacity is continually being commissioned, the coupling and interaction between the sending-side and receiving-side AC systems interconnected by large-scale DC links are becoming significant. Power impacts caused by DC commutation failures (CFs) may lead to power fluctuation on two-area interconnected power system. If the DC capacity is large enough, the stability of power system may be threatened. In this paper, using equal area rule, the stability limit of DC transmission capacity is analyzed. In addition, based on the power system three-stage power allocation theory after power impacts, the power fluctuation of the two-area AC/DC parallel transmission system caused by CFs was represented as the impulse response of a two-order linear system model. The key factors affecting the stability limit are furtherly discussed. Then the results are verified using advanced digital power system simulator (ADPSS) for the two-area IEEE-39 network model for AC/DC parallel transmission. Finally, the control measures for improving the stability of AC/DC parallel transmission system were put forward.

Modelling and control of a back‐to‐back MMC–HVDC system using ADPSS

Back-to-back modular multilevel converter–high-voltage direct current (MMC–HVDC) can realise the asynchronous interconnection of two regional power grids. It can effectively solve the power grid stability problems caused by AC–DC power transfer and avoid the risk of large-scale blackouts. Existing MMC–HVDC modelling methods are usually based on Power Systems Computer Aided Design/Electromagnetic Transients including DC (PSCAD/EMTDC), immensely simplifying the AC system. The simplified model is incapable to reflect the interaction characteristics accurately. To solve this problem, a hybrid simulation model of an actual back-to-back MMC–HVDC system is built using Advanced Digital Power System Simulator (ADPSS). ADPSS is a software developed by China Electric Power Research Institute that can realise multi-time scale hybrid simulation to simulate the mutual coupling characteristics accurately. The model includes the electromagnetic transient simulation model of the DC system, and the control system is designed. Steady-state and transient simulations are carried out to verify its function. In summary, the study provides a better reference for the analysis and designing of the practical system.

Interpolation algorithm considering simultaneous solution and instantaneous solution for power electronics electromagnetic transient simulation

In order to correctly simulate the simultaneous switching of power electronics circuits and to solve the problems of virtual power loss existing in the traditional interpolation algorithm, this article proposes interpolation algorithm considering simultaneous solution and instantaneous solution. After each integration, it searches for the switching events and determines the simultaneous switching. The simultaneous switching events are solved simultaneously. Instantaneous solution is carried out at forced commutation switching instant. The historical terms calculation method in instantaneous solution under different conditions is given, and the exact power loss of forced commutation switch is obtained. After processing all switching events during one time-step, the half-step interpolation is performed to eliminate numerical oscillations. The proposed algorithm is applied to the electromagnetic transient programme of advanced digital power system simulator (ADPSS), and the correctness and effectiveness of the algorithm are verified by simulation tests for typical power electronics circuits. The simulation results show that the proposed algorithm has high simulation accuracy and can satisfy requirements of power electronics simulation.

Online decision-making and control of power system stability based on super-real-time simulation

During power grid cascading failure, the operating point changes frequently, resulting in a mismatch or inaccuracy of online pre-decision making emergency control strategy. To solve this problem, an online power system stability decisionmaking and control method based on super-real-time simulation is presented in this paper. A decision-making and control system is developed in which the three main operation modes, offline pre-decision-making, online pre-decision-making, and real-time control, are all coordinated. To verify the method, ADPSS (advanced digital power system simulator) is used to simulate a digital power grid with about 20,000 buses. The closed-loop operation of the digital power grid and the online decisionmaking and control system are implemented. Test results show that when online pre-decision making control strategies are mismatched, aided real-time control works well and can prevent power grid stability loss.

Hybrid electromechanical-electromagnetic simulation to SVC controller based on ADPSS platform

To test the dynamic performance and damping features of a static var compensator (SVC) controller accurately in large-scale interconnected AC/DC hybrid power systems, it is of vital significance to build the detailed electromagnetic transient model. However, it is unrealistic and time-consuming to build the detailed models of all the devices in the actual large-scale power grid. Utilizing the hybrid simulation function in the advanced digital power system simulator (ADPSS) and by dividing the large-scale power grid into the electromagnetic transient sub-grids and electromechanical sub-grids, the computation speed of real-time simulation is remarkably enhanced by the parallel computational capabilities of digital simulator. The SVC controller and the nearby substation are modelled in the electromagnetic transient sub-grid, and the residue sub-networks are modelled in the electromechanical sub-grid. This paper focuses on the mechanism of the hybrid electromechanical and electromagnetic simulation, the detailed modelling and the ADPSS-based digital closed-loop test methodologies of the SVC controller. Eventually, the validity and effectiveness of the modelling and control methods are confirmed by the experimental results.

Shunt Reactors Compensation Research of UHV Accessed to Jiangxi Power Grid

Jiangxi ultra high voltage (UHV) accessed program is introduced. Based on uniform transfer equation, UHV π-type equivalent circuit is derived by considering the distributed parameter characteristics of UHV transmission line without conductance. Based on advanced digital power system simulator, the relationship of shunt reactor and steady-state voltage, as well as the relationship of shunt reactor and transient voltage, is achieved by using electromechanical and electromagnetic hybrid simulation, where the UHV between Hubei and Jiangxi is considered. Influences of shunt reactors’ location and the degree of compensation on UHV’s steady-state voltage and transient power frequency overvoltage are analyzed. The Logical results provide a meaningful guidance for the introduction of UHV power grid into Jiangxi power grid.

Influence Assessment of UHV Project on Jiangxi Power Grid

In order to face the challenge of our economy and the environment, it is needed to speed up the energy structure transition and UItra High voltage (UHV) transmission has become an inevitable choice. Researches on the influence of UHV project to Jiangxi power grid are carried out in this paper. Using advanced digital power system simulator (ADPSS), the real-time simulation model of Jiangxi power grid is build up including the UHV project. Based on the simulation model, the problem of low frequency oscillation in Jiangxi power system is studied after the UHV power transmission project accessed. The influence of the UHV transmission line faults on system stability of Jiangxi grid is also researched.

Dynamic Modeling and Power Swing Damping Control (PSDC) of SVC Using ADPSS-Based Hardware-in-the-Loop (HID) Approach

This paper presents the dynamic modeling and power swing damping control (PSDC) of the static var compensator (SVC) using hardware-in-the-loop (HID) approach based on the advanced digital power system simulator (ADPSS) platform. A brief review of the SVC and the Phillips-Heffron model of the power system with the SVC controller are presented. The power swing damping control (PSDC) is devised to enhance power system damping and mitigate low frequency oscillation of the power system under grid disturbance conditions. The coordinated HID-based real-time digital simulation method using the electromagnetic and electromechanical transient programs is proposed. To analyze the dynamic and transient control behavior of the SVC, the closed-loop control strategy of the SVC controller on the ADPSS platform is designed. The validity and effectiveness of the modeling and control methods are confirmed by the experimental results