Power Transfer Control Strategy Based on True Bipolar MMC-MTDC System

The true bipolar modular multilevel converter-based multi-terminal direct current (MMC-MTDC) DC transmission line is prone to single-pole grounding fault, which may cause overload and overcurrent of the non-fault DC line with fault poles, resulting in system protection misoperation and system collapse. Therefore, the power transfer control strategy should be adopted to improve system stability. In addition, considering that the commutator stations of true bipolar MMC-MTDC system may have unipolar faults, it is necessary to adopt the control strategy of inter-pole power transfer or inter-station power transfer to improve the transmission capacity of the system under fault conditions. In this paper, a power transfer control strategy is proposed, which is widely applicable to MMC-MTDC system. In the case of line fault, the power transfer takes into account the line power margin and the power margin of converter station. The inter-pole power transfer is better than the inter-station power transfer under the converter station fault condition, and the inter-station power transfer takes into account the priority of the power margin of the converter station. At the same time, based on the Zhangbei four-terminal flexible direct current transmission project, the Zhangbei four-terminal flexible direct current transmission system is built by using PSCAD/EMTDC, and the flexibility and effectiveness of the proposed strategy are verified by simulation.

The Mirror Reversal Mechanism on Black Hole Collapse and Singularity Eruption in Cosmic Continuum

In the Big Bang Theory and the Black Hole Theory, the existing laws of physics all fail atthe singularity, and the singularity has become a blind spot in the existing scientific theories. In Cosmiccontinuum, the cosmic system collapse into a Schwarzschild black hole under the action of a stronggravitational field, and the Planck spheres at the center of the black hole continues to collapse into darkmass bodies, forming dark celestial body and singularity. The Schwarzschild radius is the upper limit ofa black hole, and the Planck sphere is the lower limit of a black hole. The singularity is the conversionpoint between the old and new cosmic systems. The singularity erupts the Planck spheres under theaction of a strong gravitational field, and the Planck spheres expands outward to form a new cosmicsystem. The Planck sphere is both the end of the old cosmic system and the starting point of the newcosmic system. The black hole collapse and the singularity eruption are mirror images of each other.The Planck sphere is the front of the mirror, and the singularity is the back of the mirror.

The Mirror Reversal Mechanism on Black Hole Collapse and Singularity Eruption in Cosmic Continuum

In the Big Bang Theory and the Black Hole Theory, the existing laws of physics all fail atthe singularity, and the singularity has become a blind spot in the existing scientific theories. In Cosmiccontinuum, the cosmic system collapse into a Schwarzschild black hole under the action of a stronggravitational field, and the Planck spheres at the center of the black hole continues to collapse into darkmass bodies, forming dark celestial body and singularity. The Schwarzschild radius is the upper limit ofa black hole, and the Planck sphere is the lower limit of a black hole. The singularity is the conversionpoint between the old and new cosmic systems. The singularity erupts the Planck spheres under theaction of a strong gravitational field, and the Planck spheres expands outward to form a new cosmicsystem. The Planck sphere is both the end of the old cosmic system and the starting point of the newcosmic system. The black hole collapse and the singularity eruption are mirror images of each other.The Planck sphere is the front of the mirror, and the singularity is the back of the mirror.

The Mirror Reversal Mechanism on Black Hole Collapse and Singularity Eruption in Cosmic Continuum

In Cosmic continuum, the cosmic system collapse into a Schwarzschild black hole under the action of a strong gravitational field, and the Planck spheres at the center of the black hole continues to collapse into dark mass bodies, forming dark celestial body and singularity. The Schwarzschild radius is the upper limit of a black hole, and the Planck sphere is the lower limit of a black hole. The singularity is the conversion point between the old and new cosmic systems. The singularity erupts the Planck spheres under the action of a strong gravitational field, and the Planck spheres expands outward to form a new cosmic system. The Planck sphere is both the end of the old cosmic system and the starting point of the new cosmic system. The black hole collapse and the singularity eruption are mirror images of each other. The Planck sphere is the front of the mirror, and the singularity is the back of the mirror.

Predicting system collapse : application of kernel-based machine learning and inclination analysis

While many modelling methods have been developed and introduced to predict the actual state of a system at the next point of time, the purpose of this research is to present and discuss two approaches NOT to predict the exact future states, but to identify the potential for final collapse of a system. The first approach is based on kernel methods, a sub category of supervised learning, and attempts to provide a visualization method to classify the active and dead companies and predict the potential collapse of a system. The second method aims to analyze the inclination of a system by looking at the local changes that have been observed over a certain period of time in the past. Application of these modelling approaches to predict collapse in different companies belonging to two industrial sectors by looking at behaviour of their closing stock prices are discussed in this research. Advantages and limitations of each approach are also discussed.

Predicting system collapse : application of kernel-based machine learning and inclination analysis

While many modelling methods have been developed and introduced to predict the actual state of a system at the next point of time, the purpose of this research is to present and discuss two approaches NOT to predict the exact future states, but to identify the potential for final collapse of a system. The first approach is based on kernel methods, a sub category of supervised learning, and attempts to provide a visualization method to classify the active and dead companies and predict the potential collapse of a system. The second method aims to analyze the inclination of a system by looking at the local changes that have been observed over a certain period of time in the past. Application of these modelling approaches to predict collapse in different companies belonging to two industrial sectors by looking at behaviour of their closing stock prices are discussed in this research. Advantages and limitations of each approach are also discussed.

Assessing the Brazilian Electric Sector’s Financial Monitoring Milestone

The Brazilian energy sector adopted a new regulation system in 2015 due to a system collapse threat. The system was changed to contractually incorporate firms’ economic-financial monitoring. This paper aims to assess the progress of this monitoring model toward achieving its goals. Thus, we proceed with a triangulation with three analyses. First, we analyse the literature to indicate if the economic-financial monitoring shows a hybrid form of adoption as suggested by the literature as the most suitable towards achieving regulatory goals. Second, we verify the perception of the economic-financial monitoring efficiency by the regulatory agency. Third, we evaluate the behaviour of some financial indicators before and after the new regulation. Our results show that, first, the economic-financial monitoring adopts a hybrid form which may drives better monitoring. Second, the perception of the regulator regarding efficiency of the financial monitoring model is favourable. Third, our results show that the sector leverage and profitability variances were significantly reduced after the implementation of financial monitoring which indicates less Asymmetric Information and consequently, better monitoring. In general, our results indicate some uncertainty reduction and more uniform behaviour of the entire sector after adopting an economic-financial monitoring system.

Voltage Stability Analysis of Nigerian 330kV Power Grid using Static P-V Plots

Nigeria power system has been experiencing total or partial system failures in recent times and voltage instability is a strong factor. The paper seeks to perform the voltage stability analysis, based on static P-V plots, on buses located around and within the South East zone of Nigeria. An injection group containing generators to serve as the source and a sink group as loads to be monitored are created. The generators are assumed to be within their min/max MW limits. The load is increased in the sink group as well as in the source group to maintain the same generation/load balance. Load power and bus voltages (P-V) curves are plotted on the load busbars and the first busbar to reach the voltage collapse and MW transfer limit are determined. From the results obtained, at a load of 100 MW, Makurdi bus recorded a voltage of 0.9301 pu which is already below the regulatory standards of ±5% of the nominal line voltage. It entered the region of instability at a load of 245 MW. This created a situation of system instability and a possible partial system collapse. Subsequently, at a load of 260 MW, the system clearly entered unstable region giving rise to partial system collapse of the network.