Remmy Musumpuka - Academia.edu (original) (raw)
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Papers by Remmy Musumpuka
Energies
Large induction motors can have a high inrush and run-up current during starting, often up to ten... more Large induction motors can have a high inrush and run-up current during starting, often up to ten times the rated current. In weak supplies, this could be a problem, causing system stability issues and the voltage to dip below acceptable levels. In islanded systems, the capacity could be pulled below its maximum. There are several different starting methods possible, but they are often only suitable for smaller machines. One method not investigated is the use of parallel capacitor compensation during the starting because large induction motors are very inductive during the starting sequence, so that supplying reactive power may be more effective than supplying energy. This paper first investigates several different induction motors with increasing size and assesses their compensation requirements in terms of the reactive power requirement during starting. It is shown that they do generally become more inductive as they increase in size. It is illustrated, using simulations, that usi...
2021 IEEE Southern Power Electronics Conference (SPEC)
Power loads can have high starting. These can be a serious source of concern in weak grids. This ... more Power loads can have high starting. These can be a serious source of concern in weak grids. This problem is envisaged to be exacerbated by the rollout of smart microgrids. When a high power induction motor is turned on, its inrush current drawn can be more than ten times the full-load current. This transient current can cause problems in weak grid connections. The increased current is due to both power required to start the load and the increased reactive power demand during the starting process. To protect the grid connection as well as the load, energy storage units can be used to compensate for the increased power requirement. A more pragmatic approach is to reduce the reactive power requirement using tuned compensation capacitors in order to reduce the inrush current. The aim of this work is to address the selection, calculation and switching of the capacitor bank for reactive power compensation. This first requires the study of the reactive power drawn by an induction motor during starting. The capacitances are calculated and switched on to compensate the starting transient and disconnected when the machine has run up to speed using a point-on switching approach that reduces the switching transient.
IEEE Transactions on Industrial Electronics, 2022
2021 IEEE Southern Power Electronics Conference (SPEC)
2021 IEEE Southern Power Electronics Conference (SPEC)
The advent of multimedia applications over wireless networks has necessitated the need for high d... more The advent of multimedia applications over wireless networks has necessitated the need for high data rates and a reliable communication over dynamic wireless links. Adaptive Modulation and coding (AMC), Automatic Repeat re-Quest (ARQ) and Forward Error Correction (FEC) have been widely used to overcome the time varying nature of these links and consequently enhancing their performance. When AMC is used, variable number of packets can be transmitted per Coherence Time Interval (CTI) depending on the Transmission Mode (TM). The number of packets transmitted per CTI is a function of the received Signal-to-Noise Ratio (SNR). For time correlated fading, this entails that the service process is non-Markovian. In this paper we derive the first and Second Moments of the service time distribution for an M/G/1 queuing model that employs AMC for TDMA systems over time correlated Nakagamim Fading channel. We consider service times for geometrically distributed message lengths with fixed packet ...
IEEE Communications Letters, 2016
2015 6th International Conference on the Network of the Future (NOF), 2015
Energies
Large induction motors can have a high inrush and run-up current during starting, often up to ten... more Large induction motors can have a high inrush and run-up current during starting, often up to ten times the rated current. In weak supplies, this could be a problem, causing system stability issues and the voltage to dip below acceptable levels. In islanded systems, the capacity could be pulled below its maximum. There are several different starting methods possible, but they are often only suitable for smaller machines. One method not investigated is the use of parallel capacitor compensation during the starting because large induction motors are very inductive during the starting sequence, so that supplying reactive power may be more effective than supplying energy. This paper first investigates several different induction motors with increasing size and assesses their compensation requirements in terms of the reactive power requirement during starting. It is shown that they do generally become more inductive as they increase in size. It is illustrated, using simulations, that usi...
2021 IEEE Southern Power Electronics Conference (SPEC)
Power loads can have high starting. These can be a serious source of concern in weak grids. This ... more Power loads can have high starting. These can be a serious source of concern in weak grids. This problem is envisaged to be exacerbated by the rollout of smart microgrids. When a high power induction motor is turned on, its inrush current drawn can be more than ten times the full-load current. This transient current can cause problems in weak grid connections. The increased current is due to both power required to start the load and the increased reactive power demand during the starting process. To protect the grid connection as well as the load, energy storage units can be used to compensate for the increased power requirement. A more pragmatic approach is to reduce the reactive power requirement using tuned compensation capacitors in order to reduce the inrush current. The aim of this work is to address the selection, calculation and switching of the capacitor bank for reactive power compensation. This first requires the study of the reactive power drawn by an induction motor during starting. The capacitances are calculated and switched on to compensate the starting transient and disconnected when the machine has run up to speed using a point-on switching approach that reduces the switching transient.
IEEE Transactions on Industrial Electronics, 2022
2021 IEEE Southern Power Electronics Conference (SPEC)
2021 IEEE Southern Power Electronics Conference (SPEC)
The advent of multimedia applications over wireless networks has necessitated the need for high d... more The advent of multimedia applications over wireless networks has necessitated the need for high data rates and a reliable communication over dynamic wireless links. Adaptive Modulation and coding (AMC), Automatic Repeat re-Quest (ARQ) and Forward Error Correction (FEC) have been widely used to overcome the time varying nature of these links and consequently enhancing their performance. When AMC is used, variable number of packets can be transmitted per Coherence Time Interval (CTI) depending on the Transmission Mode (TM). The number of packets transmitted per CTI is a function of the received Signal-to-Noise Ratio (SNR). For time correlated fading, this entails that the service process is non-Markovian. In this paper we derive the first and Second Moments of the service time distribution for an M/G/1 queuing model that employs AMC for TDMA systems over time correlated Nakagamim Fading channel. We consider service times for geometrically distributed message lengths with fixed packet ...
IEEE Communications Letters, 2016
2015 6th International Conference on the Network of the Future (NOF), 2015