Development of a High-Power Capacity Open Source Electrical Stimulation System to Enhance Research into FES-Assisted Devices: Validation of FES Cycling

Since the first Cybathlon 2016, when twelve teams competed in the FES bike race, we have witnessed a global effort towards the development of stimulation and control strategies to improve FES-assisted devices, particularly for cycling, as a means to practice a recreational physical activity. As a result, a set of technical notes and research paved the way for many other studies and the potential behind FES-assisted cycling has been consolidated. However, engineering research needs instrumented devices to support novel developments and enable precise assessment. Therefore, some researchers struggle to develop their own FES-assisted devices or find it challenging to implement their instrumentation using commercial devices, which often limits the implementation of advanced control strategies and the possibility to connect different types of sensor. In this regard, we hypothesize that it would be advantageous for some researchers in our community to enjoy access to an entire open-source FES platform that allows different control strategies to be implemented, offers greater adaptability and power capacity than commercial devices, and can be used to assist different functional activities in addition to cycling. Hence, it appears to be of interest to make our proprietary electrical stimulation system an open-source device and to prove its capabilities by addressing all the aspects necessary to implement a FES cycling system. The high-power capacity stimulation device is based on a constant current topology that allows the creation of biphasic electrical pulses with amplitude, width, and frequency up to 150 mA, 1000 µs, and 100 Hz, respectively. A mobile application (Android) was developed to set and modify the stimulation parameters of up to eight stimulation channels. A proportional-integral controller was implemented for cadence tracking with the aim to improve the overall cycling performance. A volunteer with complete paraplegia participated in the functional testing of the system. He was able to cycle indoors for 45 min, accomplish distances of more than 5 km using a passive cycling trainer, and pedal 2400 m overground in 32 min. The results evidenced the capacity of our FES cycling system to be employed as a cycling tool for individuals with spinal cord injury. The methodological strategies used to improve FES efficiency suggest the possibility of maximizing pedaling duration through more advanced control techniques.

Global Growth in Offshore Wind Turbine Technology

Due to the commissioning of floating wind units, the latest technological developments, significant growth, and improvements in turbines, developments in offshore wind power capacity are estimated to increase faster than in the last two decades. The total installed offshore wind power capacity, which is currently 35 GW, is predicted to be approximately 382 GW by 2030 and approximately 2,002 GW by 2050. For this reason, attempts are proposed to lower levelised cost of electricity (LCOE) for offshore wind power generation more than for other energy sources. In this study firstly, the global growth in the nominal capacity and size of offshore wind turbines over the last twenty years is examined. Then, the effects of this increase in nominal capacity and size on the LOCE, total installation cost (TIC), and turbine capacity factor are investigated. In parallel with this development, the changes in distance to shore and water depth for installation offshore wind power plants are reviewed according to the years. In addition, the effects of this global growth on wind farm capacity, turbine-specific power capacity, number of turbines per GW, and area needed per GW are investigated and discussed in detail.

Graphdiyne Oxide Composite Membranefor Active Electrolyte Enhanced Supercapacitor with super long self-discharge time

Activate electrolyte enhanced supercapacitors (AEESCs) are considered as promising tools for power capacity due to their high specific capacitance and simple creation form. However, there are many challenges, such as...

The Portuguese ‘New State’ and the Diffusion of Authoritarian Models in Interwar Latin America

As an authoritarian ‘gravity centre’ in the interwar period, the Portuguese New State was not the product of strong propaganda or power capacity. Its force of attraction derived, essentially, from having an international means of diffusion: important segments of the Catholic Church's organizations, its associated intellectual politicians, and particularly from having led a corporatist and authoritarian political system model. How and why did Salazar's New State inspire some of the new political institutions proposed by radical right-wing elites or created by many of these regimes? This article tackles this issue by adopting a transnational and comparative research approach, paying particular attention to the primary mediators of its diffusion and analyzing institutional reform processes in selected processes of crises and transitions to authoritarianism in Latin America.

Design of protection and control scheme for hybrid nanogrid

Nanogrid is “The new ray of hope” for people living in remote isolated locations as well as where power supply reliability is poor. A nanogrid is a small power capacity distribution system with the ability to operate standalone or with a utility grid. It consists of local power production supplying local loads and energy storage systems. In this paper, an innovative inverter design is presented, which converts the power in a single stage. It is superior to the traditional two-stage inverter system and can supply hybrid loads (AC and DC loads) with a single input. System AC and DC bus voltages are regulated under both steady-state and dynamic load variation conditions in the nanogrid. Simulation results are presented which confirm the suitability of the inverter and its control strategy for a hybrid nanogrid system.

Energy in South Africa

South Africa’s long dependence on imported oil and domestic coal leaves it ill prepared to navigate the Fourth Industrial Revolution and decarbonization. In 1998, after a long history of state intervention in energy markets, post-apartheid policy set new market-orientated reform goals. Following a promising start, the pendulum swung back towards state intervention. In 2018 a combination of factors, including an electricity supply crisis, brought about indications of a return to market reforms, albeit an attenuated version thereof, particularly in power generation. Petroleum markets have been stuck in impasses associated with old-style regulation and social policies entangled in price regulation. Mismanagement and corruption have taken a toll as has private investor insistence on financial support. Good progress has been made in electrification, electricity subsidies for the poor, gas infrastructure, and renewable power capacity auctions. Technological innovation in renewable power offers reduced economies of scale and much promise for energy markets.

Torque Analysis of 2 KW BLDC (Brushless Direct Current) Motor with Speed Variations in Electric Cars E-Falco

The motor releases torque and power to drive an electric car by carrying the load from a start position until it travels at the desired speed. The KMLI E-Falco electric car uses a BLDC type electric motor with a power capacity of 2 kW. To find out the amount of torque of a 2 kW BLDC motor when driving with variations in speed, it can be done by manual calculations using the torque equation and doing a dynotest test. The dynotest results show that the motor torque at the speed: 1 km/h is 1 Nm, 10 km/h is 131 Nm, 13 km/h is 228 Nm, 20 km/h is 225 Nm, 30 km/h is 219 Nm, 40 km / h is 188 Nm, 50 km / hour is 145 Nm, 60 km / h is 113 Nm, and 70 km / h is 85 Nm. From the results of the dynotest, it shows that the peak torque occurs at a speed of 13 km / h at 228 Nm. Racing software installed in the controller can increase the motor torque by four times at a speed variation of 13-70 km/h based on the results of the dynotest above. Keywords: motor, BLDC, torque, speed, acceleration.