Understanding the merits of six-phase interior permanent magnet synchronous machines (IP-MSMs) over their three-phase counterparts, this paper analyses the six-phase machine for optimal parameter and performance considerations. Initially, a mathematical model of the six-phase IPMSM is developed employing the dq-axis theory and performance predicted by the model is verified under identical operating conditions with those using a machine designed and tested through finite element analysis (FEA). The developed and verified machine model is then employed to exclusively derive the relation between various machine parameters in order to obtain optimum flux weakening region in the six-phase IPMSM. Thereafter, the equations derived on the basis of maximum torque per ampere (MTPA) control theory are analyzed to understand the effect of various parameters and variables in influencing the machine’s performance in the ‘constant torque’ region and ‘constant power’ region, power output capability, a ratio of reluctance torque to magnet-assisted torque with changes in the stator current vector etc. This is the contribution of this paper.

Amid the COVID-19 pandemic and countrywide lockdown, the super-cyclone Amphan collided with the eastern coast of India, majorly affecting the Indian state of West Bengal. The lockdown restricted the industrial emissions of greenhouse gases known for increasing the average global temperature, however the sea-surface temperature (SST) profile over the Bay of Bengal indicated higher than average SST values in preceding 5 years. The unexpected increase in sea-surface temperature might have played a major role in formation cyclonic disturbances over the Bay of Bengal, which might have triggered the formation of super cyclone Amphan. The anomalous increase in average SST could be attributed to the sudden lowering of particulate matter concentration due to the lockdown, which resulted in the increase in levels of solar insolation on the sea-surface due to the absence of particulate matter load, which reflects/absorbs the incoming solar radiation to the surface keeping the sea-surface temperature at lower levels.

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ABSTRACT. This paper deals with the security aspects of power system by evaluating the severity of transmission line outage. MW security assessment is made by determining the power flow in the line using load flow for each contingency. The severity of contingency is measured using a scalar index called performance index (PI). DC load flow and Fast Decoupled load flow are used as approximate and exact load flow methods for MW security assessment respectively. Contingency analysis is carried out and ranked lists in the decreasing order of severity based on PI values are prepared for standard test systems. The severity of line is evaluated and compared using these load flow methods. A new method is proposed to avoid Masking problems in MW security assessment. Security analysis is made on standard test systems such as 5, 6, IEEE 14 and IEEE 30 bus systems under present study.

This paper deals with the security aspects of power system by evaluating the severity of transmission line outage. MW security assessment is made by determining the power flow in the line using load flow for each contingency. The severity of contingency is measured using a scalar index called performance index (PI). DC load flow and Fast Decoupled load flow are used as approximate and exact load flow methods for MW security assessment respectively. Contingency analysis is carried out and ranked lists in the decreasing order of severity based on PI values are prepared for standard test systems. The severity of line is evaluated and compared using these load flow methods. A new method is proposed to avoid Masking problems in MW security assessment. Security analysis is made on standard test systems such as 5, 6, IEEE 14 and IEEE 30 bus systems under present study.