Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928912
N. A. Rufa'I, Li Zhang, B. Chong
Renewable energy sources such as solar and wind require power converters and harmonic filters for interconnection with the grid. Central to the operation of such systems is the controller, which ensures that the maximum possible power is transferred from the source to the grid. Of these controllers, the proportional-integral (PI) controller is the most commonly used, owing to its ease of implementation. This report therefore aims at comparing the operation of the PI controller with its stationary reference frame equivalent known as the proportional-resonant (PR) controller. Both controllers are implemented in the voltage oriented control scheme for a three phase converter connected to a weak grid through an LCL filter. The characteristics of the controllers are analysed and compared in both the time and frequency domains. Simulation results validate the performance of each controller.
{"title":"Comparison of PI and PR Controllers with Adaptive Notch Filter for LCL Filtered Grid-Tie Converters under Weak Grid","authors":"N. A. Rufa'I, Li Zhang, B. Chong","doi":"10.1109/PowerAfrica.2019.8928912","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928912","url":null,"abstract":"Renewable energy sources such as solar and wind require power converters and harmonic filters for interconnection with the grid. Central to the operation of such systems is the controller, which ensures that the maximum possible power is transferred from the source to the grid. Of these controllers, the proportional-integral (PI) controller is the most commonly used, owing to its ease of implementation. This report therefore aims at comparing the operation of the PI controller with its stationary reference frame equivalent known as the proportional-resonant (PR) controller. Both controllers are implemented in the voltage oriented control scheme for a three phase converter connected to a weak grid through an LCL filter. The characteristics of the controllers are analysed and compared in both the time and frequency domains. Simulation results validate the performance of each controller.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121026143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928795
J. Kalezhi, D. Rwegasira, I. Dhaou, H. Tenhunen
The depletion of water table coupled with the decrease in rainfall due to climate change has pushed international communities to look for better ways to save water. Furthermore, access to the water table in disconnected communities in off-grid locations is a challenge to many African countries. These challenges negatively affect farming activities where irrigation plays an important role. In this paper, we propose a sustainable and smart DC microgrid irrigation system using multi-agent systems along with Internet of Things technologies. The system is composed of a microgrid connected water pumping system and Internet of Things enabled sensors for irrigation. An algorithm that uses an agent-based approach to regulate energy demand from the PV system and controls irrigation is also introduced. The features of the proposed system have been compared against features for related systems.
{"title":"A DC Microgrid Smart-Irrigation System Using Internet of Things Technology","authors":"J. Kalezhi, D. Rwegasira, I. Dhaou, H. Tenhunen","doi":"10.1109/PowerAfrica.2019.8928795","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928795","url":null,"abstract":"The depletion of water table coupled with the decrease in rainfall due to climate change has pushed international communities to look for better ways to save water. Furthermore, access to the water table in disconnected communities in off-grid locations is a challenge to many African countries. These challenges negatively affect farming activities where irrigation plays an important role. In this paper, we propose a sustainable and smart DC microgrid irrigation system using multi-agent systems along with Internet of Things technologies. The system is composed of a microgrid connected water pumping system and Internet of Things enabled sensors for irrigation. An algorithm that uses an agent-based approach to regulate energy demand from the PV system and controls irrigation is also introduced. The features of the proposed system have been compared against features for related systems.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121233923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928743
Ahmed Ali
This research paper is presented to design a system that will monitor and protects the electrical loads from under voltage and over voltage supply, which may be due to unforeseen adverse effects of electrical voltages or voltage fluctuations. These adverse effects of voltage will affect the power quality that is being supplied to the electrical loads. Power quality can be defined as a steady supply voltage that stays within the prescribed ranges without the adequate/prescribed range of power supply; the electrical loads may malfunction, overheat, fail prematurely, or not operate at all, subsequently it is very vital to ensure that the correct range of voltage is being supplied to electrical loads. With this system in place, any adverse effects of voltages, by activating its tripping mechanism if the voltage supplied to the loads is not within the desired range/limits and safely isolate the electrical loads.
{"title":"Under Voltage and Over Voltage Monitor to Protect the Electrical Load","authors":"Ahmed Ali","doi":"10.1109/PowerAfrica.2019.8928743","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928743","url":null,"abstract":"This research paper is presented to design a system that will monitor and protects the electrical loads from under voltage and over voltage supply, which may be due to unforeseen adverse effects of electrical voltages or voltage fluctuations. These adverse effects of voltage will affect the power quality that is being supplied to the electrical loads. Power quality can be defined as a steady supply voltage that stays within the prescribed ranges without the adequate/prescribed range of power supply; the electrical loads may malfunction, overheat, fail prematurely, or not operate at all, subsequently it is very vital to ensure that the correct range of voltage is being supplied to electrical loads. With this system in place, any adverse effects of voltages, by activating its tripping mechanism if the voltage supplied to the loads is not within the desired range/limits and safely isolate the electrical loads.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123357892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928639
O. Okpako, H. Rajamani, K. Anoh, P. Adamu, Raed Abdel-Alhameed
In residential homes, domestic energy storage in batteries have been proposed by many to support the grid. To foster its integration into the grid, virtual power plant (VPP) technology is used. In this paper, we evaluate Peukert condition of domestic battery storage within a given distribution level market. An evolutionary algorithm is applied to optimize the social welfare of stakeholders in a community VPP at different levels of Peukert conditions. The dynamic load performance of the VPP with respect to the grid requirements for demand-side management (DSM) is also presented to evaluate the impact of the Peukert effect on DSM. The results show that the social welfare of the VPP stakeholders decreases as Peukert effects increase.
{"title":"Peukert Effects on Domestic Energy Storage in Virtual Power Plants","authors":"O. Okpako, H. Rajamani, K. Anoh, P. Adamu, Raed Abdel-Alhameed","doi":"10.1109/PowerAfrica.2019.8928639","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928639","url":null,"abstract":"In residential homes, domestic energy storage in batteries have been proposed by many to support the grid. To foster its integration into the grid, virtual power plant (VPP) technology is used. In this paper, we evaluate Peukert condition of domestic battery storage within a given distribution level market. An evolutionary algorithm is applied to optimize the social welfare of stakeholders in a community VPP at different levels of Peukert conditions. The dynamic load performance of the VPP with respect to the grid requirements for demand-side management (DSM) is also presented to evaluate the impact of the Peukert effect on DSM. The results show that the social welfare of the VPP stakeholders decreases as Peukert effects increase.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124042918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928641
A. Aluko, D. Dorrell, R. Pillay-Carpanen, E. Ojo
modern power systems present an energy mix that incorporates an increasing number of power electronics based devices such as energy storage systems, solar power systems, high voltage direct current links, etc. These devices do not have inherent inertia like traditional systems to counteract frequency deviations during disturbances such as load imbalance. A virtual inertia controller in an energy storage system is presented in this paper to mitigate the frequency instability during system disturbances. Fuzzy logic control is proposed as an intelligent control technique to provide adequate inertia response to drive the system back to steady state during load disturbance. The system was modelled and analysed using MATLAB/SIMULINK software.
{"title":"Frequency Control of Modern Multi-Area Power Systems Using Fuzzy Logic Controller","authors":"A. Aluko, D. Dorrell, R. Pillay-Carpanen, E. Ojo","doi":"10.1109/PowerAfrica.2019.8928641","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928641","url":null,"abstract":"modern power systems present an energy mix that incorporates an increasing number of power electronics based devices such as energy storage systems, solar power systems, high voltage direct current links, etc. These devices do not have inherent inertia like traditional systems to counteract frequency deviations during disturbances such as load imbalance. A virtual inertia controller in an energy storage system is presented in this paper to mitigate the frequency instability during system disturbances. Fuzzy logic control is proposed as an intelligent control technique to provide adequate inertia response to drive the system back to steady state during load disturbance. The system was modelled and analysed using MATLAB/SIMULINK software.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131463306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928646
R. Chidzonga, B. Nleya
This article looks at optimizing cost of electricity for a small residential microgrid. Each household has renewable generation capability and daily load is portioned into essential and schedulable loads. Dual tariffs exist, for buying and the other for in-feed into the grid. The optimization consist of scheduling decisions for suitable loads as well amount of power to sell or procure from the utility depending on availability and prevailing pricing. Assuming availability of time-variant energy parameters, a global optimization problem is formulated whose solutions leads to quantification of the optimal quantity of energy purchased and sold for each of the households. When the unrealistic assumption of availability of information is removed from the implementation of the global optimization, an online algorithm that only requires the current values of the time varying supply and demand processes shows by simulation that the distributed algorithm can realise credible scheduling of prosumer household electricity usage.
{"title":"Energy Optimization for a Smart Home with Renewable Generation","authors":"R. Chidzonga, B. Nleya","doi":"10.1109/PowerAfrica.2019.8928646","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928646","url":null,"abstract":"This article looks at optimizing cost of electricity for a small residential microgrid. Each household has renewable generation capability and daily load is portioned into essential and schedulable loads. Dual tariffs exist, for buying and the other for in-feed into the grid. The optimization consist of scheduling decisions for suitable loads as well amount of power to sell or procure from the utility depending on availability and prevailing pricing. Assuming availability of time-variant energy parameters, a global optimization problem is formulated whose solutions leads to quantification of the optimal quantity of energy purchased and sold for each of the households. When the unrealistic assumption of availability of information is removed from the implementation of the global optimization, an online algorithm that only requires the current values of the time varying supply and demand processes shows by simulation that the distributed algorithm can realise credible scheduling of prosumer household electricity usage.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127359134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928856
I. Okoro, Clinton Enwerem
The separately-excited DC motor is a high-performance variable speed drive vital for industrial applications such as robotics, actuation, control and guided manipulation because of its precision, simplicity, continuous control feature and wide speed range. Hence there is need to accurately regulate and drive the motor at desired speed. The individual armature voltage and field current methods are flawed in their inability to control the motor speed over a wider range. Hence this paper is proposing a combined armature voltage and field current control method using Internal Model Control (IMC) feedback control scheme that will ensure reference speed tracking, a fast and non-oscillatory response for the DC motor speed. The armature voltage and field current control techniques are both modelled, fully capturing the dynamic effects of the armature and field excitation of the DC motor. The derived model is then used to obtain optimal settings for a PID controller that will control the motor speed. This model-based controller enhances the performance of the motor. Computer simulations are presented to show the effectiveness of the proposed control scheme.
{"title":"Model-based Speed Control of a DC Motor Using a Combined Control Scheme","authors":"I. Okoro, Clinton Enwerem","doi":"10.1109/PowerAfrica.2019.8928856","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928856","url":null,"abstract":"The separately-excited DC motor is a high-performance variable speed drive vital for industrial applications such as robotics, actuation, control and guided manipulation because of its precision, simplicity, continuous control feature and wide speed range. Hence there is need to accurately regulate and drive the motor at desired speed. The individual armature voltage and field current methods are flawed in their inability to control the motor speed over a wider range. Hence this paper is proposing a combined armature voltage and field current control method using Internal Model Control (IMC) feedback control scheme that will ensure reference speed tracking, a fast and non-oscillatory response for the DC motor speed. The armature voltage and field current control techniques are both modelled, fully capturing the dynamic effects of the armature and field excitation of the DC motor. The derived model is then used to obtain optimal settings for a PID controller that will control the motor speed. This model-based controller enhances the performance of the motor. Computer simulations are presented to show the effectiveness of the proposed control scheme.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126767507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928657
O. J. Ayamolowo, Ayodeji Olalekan Salau, S. Wara
Nigeria being the most populous African nation has recorded an increasing gap between the power supplied and power demanded. In order to curb this challenge, the Nigeria power sector has undergone several power reforms. However, these reforms have only helped in restructuring the power sector with no significant improvement in power delivery. During the past decades, several reforms have been geared towards restructuring the power generation, transmission and distribution sector in order to improve industrialization. This paper reviews the various reforms which have taken effect in the Nigeria power sector and their influence in improving the Nigerian power sector. Furthermore, succinct information on the present performance of the power sector is provided highlighting its deficiency, but however, proffering workable solutions to the lingering challenges considering the abundant availability of renewable energy sources in Nigeria as a means of meeting the goals of Vision 20:2020.
{"title":"The Power Industry Reform in Nigeria: The Journey So Far","authors":"O. J. Ayamolowo, Ayodeji Olalekan Salau, S. Wara","doi":"10.1109/PowerAfrica.2019.8928657","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928657","url":null,"abstract":"Nigeria being the most populous African nation has recorded an increasing gap between the power supplied and power demanded. In order to curb this challenge, the Nigeria power sector has undergone several power reforms. However, these reforms have only helped in restructuring the power sector with no significant improvement in power delivery. During the past decades, several reforms have been geared towards restructuring the power generation, transmission and distribution sector in order to improve industrialization. This paper reviews the various reforms which have taken effect in the Nigeria power sector and their influence in improving the Nigerian power sector. Furthermore, succinct information on the present performance of the power sector is provided highlighting its deficiency, but however, proffering workable solutions to the lingering challenges considering the abundant availability of renewable energy sources in Nigeria as a means of meeting the goals of Vision 20:2020.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114671517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928915
O. Oni, A. Swanson, R. P. Carpanen
This paper analyzes the transient response of a multiterminal HVDC link during dc line fault and partial de-block of the inverter station. A simplified model of a four-terminal system was analyzed for current order control settings. Then, a parallel four-terminal LCC based converter system was modelled and analyzed on PSCAD. A dc line fault was applied at the middle of the transmission line. The waveforms showed a transient over-current at the rectifier station. A partial de-blocking measure was introduced to reduce the inflow of fault current into the inverter station. This resulted in a reduced active power transfer at the rectifier station. The system was able to maintain its steady state operating state after the fault period without any occurrence of commutation failure. The results validate the viability of MTDC for bulk power transfer and the fault ride through capability of the controller.
{"title":"Impact of Partial De-blocking of MTDC Link during DC Fault","authors":"O. Oni, A. Swanson, R. P. Carpanen","doi":"10.1109/PowerAfrica.2019.8928915","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928915","url":null,"abstract":"This paper analyzes the transient response of a multiterminal HVDC link during dc line fault and partial de-block of the inverter station. A simplified model of a four-terminal system was analyzed for current order control settings. Then, a parallel four-terminal LCC based converter system was modelled and analyzed on PSCAD. A dc line fault was applied at the middle of the transmission line. The waveforms showed a transient over-current at the rectifier station. A partial de-blocking measure was introduced to reduce the inflow of fault current into the inverter station. This resulted in a reduced active power transfer at the rectifier station. The system was able to maintain its steady state operating state after the fault period without any occurrence of commutation failure. The results validate the viability of MTDC for bulk power transfer and the fault ride through capability of the controller.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117330695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-08-01DOI: 10.1109/PowerAfrica.2019.8928736
I. Garba
Access to energy is vital in addressing many of the current global sustainable development adversities that continue to impact on people’s economic, social and physical well-being. Despite the expanding attention from national and international governments, agencies and academics, energy poverty remains a reality for millions of people living in Africa. As a whole, the African energy sector is described to be the most impoverished part of the global energy system. The aim of this paper is to review the challenges and opportunities of the African energy system: focusing on the most demanded, yet, most overlooked energy service - cooking. In addition, it presents empirical results illustrating the effects of the inaccessibility to modern cooking fuels on aspects of sustainable social development: using the panel data of the African region.
{"title":"Cooking fuels and sustainable social development: the case of Africa","authors":"I. Garba","doi":"10.1109/PowerAfrica.2019.8928736","DOIUrl":"https://doi.org/10.1109/PowerAfrica.2019.8928736","url":null,"abstract":"Access to energy is vital in addressing many of the current global sustainable development adversities that continue to impact on people’s economic, social and physical well-being. Despite the expanding attention from national and international governments, agencies and academics, energy poverty remains a reality for millions of people living in Africa. As a whole, the African energy sector is described to be the most impoverished part of the global energy system. The aim of this paper is to review the challenges and opportunities of the African energy system: focusing on the most demanded, yet, most overlooked energy service - cooking. In addition, it presents empirical results illustrating the effects of the inaccessibility to modern cooking fuels on aspects of sustainable social development: using the panel data of the African region.","PeriodicalId":308661,"journal":{"name":"2019 IEEE PES/IAS PowerAfrica","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129039351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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