Stability Analysis Of Power Grid Research Articles

Power grid stability analysis using pipeline machine

Power grid stability analysis using pipeline machine

Dynamic stability analysis of power grid in high proportion new energy access scenario based on deep learning

The “carbon peaking and carbon neutralization” scheme formulated to solve the power energy shortage makes the new energy units incorporated into the power grid on a large scale. The randomness and volatility caused by the high proportion of new energy access have a certain impact on the dynamic stability of the power grid. Based on the dynamic stability theory, this paper applies the dual-stream CNN algorithm in the deep learning technology to model, takes the power of each node and line as the input and the key eigenvalue as the output, quickly identifies the main oscillation modes of the power system, makes a qualitative evaluation. Combined with the actual power grid analysis, the interval oscillation frequencies of the system are 0.57 Hz and 0.53 Hz respectively, which belong to strongly damped oscillation and can be quickly subsided after being excited. It can be concluded that the dual-stream CNN algorithm can provide reliable technical support for subsequent dispatching operation, and is conducive to improving the safe and stable operation level of power system.

Stability Analysis of Power Grid Connected With Direct-Drive Wind Farm Containing Virtual Inertia Based on Integrated Dissipation Energy Model

Concerning the difficulty in unified modeling of direct-drive wind farm with virtual inertia and the unknown cause of low frequency oscillation, a detailed model of integrated dissipation energy of direct-drive wind farm is built. First, the dissipation energy model of wind generator and the integrated dissipation energy model of direct-drive wind farm containing virtual inertia and PLL is derived and built. On this basis, according to different sources of integrated dissipation energy, it is decomposed into free dissipation energy, resonant dissipation energy and forced dissipation energy. These three components respectively characterize the contribution of inherent damping, generator-grid coupled resonance and generator-grid interaction to the stability of system. And then, how the variation of wind speed and generator location affects the stability of system is analyzed quantitatively using the integrated dissipation energy. Finally, the model of IEEE 10-machine 39-bus system connected with direct-drive wind farm is built in RTDS for hardware-in-the-loop tests. Simulation results verify that, the detailed model exhibits three different oscillation states, and each generator in the wind farm contributes differently to system oscillation. The traditional equivalent model of wind farm only exhibits one oscillation state and cannot reflect the difference in contributions of generators, thus it may wrongly identify the stability of system, even aggravate oscillation.

Transient stability analysis of power grids with admissible and maximal robust positively invariant sets

Abstract The energy transition is causing many stability-related challenges for power systems. Transient stability refers to the ability of a power grid’s bus angles to retain synchronism after the occurrence of a major fault. In this paper a set-based approach is presented to assess the transient stability of power systems. The approach is based on the theory of barriers, to obtain an exact description of the boundaries of admissible sets and maximal robust positively invariant sets, respectively. We decompose a power system into generator and load components, replace couplings with bounded disturbances and obtain the sets for each component separately. From this we deduce transient stability properties for the entire system. We demonstrate the results of our approach through an example of one machine connected to one load and a multi-machine system.

Research on obtaining method of rotor moment of inertia of synchronous generator set suitable for different rated speed

Aiming at the problem that the moment of inertia of the rotor of the generator set is different from that of the generator set under different load rejection, according to the energy conversion characteristics of the generator set during the rotor rotation, the energy conversion balance equation of the rotor rotation process is put forward, which is applied to the load rejection process of the generator set under different load and calculated and analyzed, and the accurate moment of inertia of the rotor of the generator set is obtained, this method improves the accuracy of kinetic energy of generator, which is one of the parameters of generator model in power grid stability analysis.

A Framework for Dynamic Stability Analysis of Power Systems With Volatile Wind Power

We propose a framework employing stochastic differential equations to facilitate the long-term stability analysis of power grids with intermittent wind power generations. This framework takes into account the discrete dynamics which play a critical role in the long-term stability analysis, incorporates the model of wind speed with different probability distributions, and also develops an approximation methodology (by a deterministic hybrid model) for the stochastic hybrid model to reduce the computational burden brought about by the uncertainty of wind power. The theoretical and numerical studies show that a deterministic hybrid model can provide an accurate trajectory approximation and stability assessments for the stochastic hybrid model under mild conditions. In addition, we discuss the critical cases that the deterministic hybrid model fails and discover that these cases are caused by a violation of the proposed sufficient conditions. Such discussion complements the proposed framework and methodology and also reaffirms the importance of the stochastic hybrid model when the system operates close to its stability limit.

Modeling & Simulating of Hami-Zhengzhou UHVDC Transmission Project and Security & Stability Analysis of Send-Side Power System

Hami-Zhengzhou ±800kV DC project is the first ultra high-voltage project for Xinjiang power transmission, it is also the first DC transmission project binding thermal and wind power, with bipolar low-end operation in 2013 and bipolar operation in the middle of 2014. The rated power is 8,000MW. This article focused on Hami-Zhengzhou HVDC transmission system, established the electromechanical model, which improved commutation failure treatment in the traditional DC control system and made the simulation results more close to the real operation condition. Based on this model, security and stability analysis of power grid was carried out and the corresponding control strategies/schemes were brought up.