scholarly journals Design of closed-loop control for Solar PV based Multi-Level Inverter

2019 ◽  
Vol 9 (2S3) ◽  
pp. 123-129
Keyword(s):  
Closed Loop ◽  
Pulse Width Modulation ◽  
Input Voltage ◽  
Multilevel Inverter ◽  
Modulation Method ◽  
Closed Loop Control ◽  
Solar Pv ◽  
Loop Control ◽  
Switching Losses ◽  
Capacitor Voltage

Photovoltaic (PV) based multilevel inverters (MLI) have emerged as one of the best alternatives for grid/standalone applications. MLIs offer high range power handling capability with low current and voltage distortion and lesser switching losses as compare to the traditional two-level inverter. Major challenges with generally used multilevel inverter topologies relates to capacitor voltage variation, modulation techniques, and control. The major center of attention of research in this paper is to build up sophisticated modulation and voltage balancing methods for multilevel inverter topologies, competent to reach capacitor voltage parameter and to decrease power switching losses of the inverters. The present paper focuses on closed-loop control of multilevel flying capacitor inverter (FCI). In FCI, the phase shift (PS) based pulse width modulation method is designed and investigated. The closed-loop controller is designed with input voltage control of MLI, whose source is solar PV based Boost converter. Reported simulation results prove the superiority of the closed loop control in maintaining the desired output voltage for various reference values.

scholarly journals A Novel DC-DC Converter Based Closed Loop Control of BLDC Motor for SPV fed Water Pumping System

2020 ◽  
Vol 06 (09) ◽  
pp. 240-247
Author(s):  
V Mounika and Tejavath Suhasini
Keyword(s):  
Closed Loop ◽  
Maximum Efficiency ◽  
Closed Loop Control ◽  
Solar Photovoltaic ◽  
Bldc Motor ◽  
Solar Pv ◽  
Efficient Operation ◽  
Loop Control ◽  
Pumping System ◽  
Water Pumping

This Paper Presents Novel DC-DC Converter Based Closed Loop Control of BLDC Motor for SPV fed Water Pumping System Solar Photovoltaic (SPV) Array fed Water pumping System Utilizing Buck-boost DC-DC Converter in order to extract the maximum available power from Solar system. Solar energy has the greatest availability compared to other energy sources. For such solar PV systems, maximum power point tracking control is preferred for efficient operation. This concept is dealing with INC method which is one of the MPPT methods. This study deals with a buck–boost converter controlled solar photovoltaic (SPV) array fed water pumping in order to achieve the maximum efficiency of an SPV array and the soft starting of a permanent magnet brushless DC (BLDC) motor. The current sensors normally used for speed control of BLDC motor are completely eliminated. The speed of BLDC motor is controlled through the variable DC-link voltage of a voltage-source inverter (VSI). The VSI is operated by fundamental frequency switching, avoiding the losses due to high-frequency switching, in order to enhance the efficiency of the proposed system.

Improved Control of Open-Center Systems for Haptic Applications

2005 ◽  
Author(s):  
M. E. Kontz ◽  
J. D. Huggins ◽  
W. J. Book ◽  
J. G. Frankel
Keyword(s):  
Closed Loop ◽  
Input Voltage ◽  
Closed Loop Control ◽  
Pressure Regulator ◽  
Load Pressure ◽  
Loop Control ◽  
Load Sensing ◽  
System A ◽  
System Pressure ◽  
Valve Assembly

The use of haptic interfaces to control mobile hydraulic machinery has several enhancing features over traditional human-machine-interfaces compromising of joysticks/levers. A prohibitive attribute of these systems is cost due to added complexity. One way to limit this cost is to use lower cost hydraulic components such as a constant displacement pumps and proportional directional control valves. In this type of system, a main pressure regulator is needed to supply the other closed-center valves with pressure and dump the additional flow from the pump to tank. An energy-saving solution has a load-sensing pressure regulator that maintains the system pressure a preset margin above the highest active load pressure. With the addition of pressure compensators on each proportional valve, these valves can provide steady-state flow proportional to an input voltage generated from a joystick. Using these valves for haptic applications requires closed-loop control. Applying closed-loop control to these valves can excite instabilities in the valve assembly due to complex interactions and nonlinearities in the load-sensing pressure regulator. This paper describes and analyzes these interactions. It also shows through experimental examples of how these characteristics limit closed-loop performance and destabilize the system. A possible valve modification is presented and closed-loop performance is compared using the original and modified system.

scholarly journals Multiple Modulation Strategy of Flying Capacitor DC/DC Converter

Electronics ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 774 ◽  
Author(s):  
Pengcheng Li ◽  
Chunjiang Zhang ◽  
Sanjeevikumar Padmanaban ◽  
Leonowicz Zbigniew
Keyword(s):  
Closed Loop ◽  
Modulation Method ◽  
Closed Loop Control ◽  
Voltage Level ◽  
Loop Control ◽  
Dc Microgrids ◽  
Input And Output ◽  
Bidirectional Converter ◽  
Capacity Level ◽  
Current Difference

Flying-capacitor multiplexed modulation technology is suitable for bipolar DC microgrids with higher voltage levels and higher current levels. The module combination and corresponding modulation method can be flexibly selected according to the voltage level and capacity level. This paper proposes a bipolar bidirectional DC/DC converter and its interleaved-complementary modulation strategy that is suitable for bipolar DC microgrids. The converter consists of two flying-capacitor three-level bidirectional DC/DC converters that are interleaved in parallel 90°, and then cascaded with another module to form a symmetrical structure of the upper and lower arms; the complementary modulation of the upper and lower half bridges constitutes an interleaved complementary multilevel bidirectional DC/DC converter. If the bidirectional converter needs to provide a stronger overcurrent capability, more bridge arms can be interleaved in parallel. Once n bridge arms are connected in parallel, the bridge arms should be interleaved 180°/n in parallel. In bipolar DC microgrids, the upper and lower arms should be complementarily modulated, and the input and output are isolated by the inductance. To solve the current difference, caused by the inconsistent parasitic, the voltage-current double closed-loop-control is used, and the dynamic response is faster during bidirectional operation. This paper proposes theoretical analysis and experiments that verify bipolar bidirectional DC/DC converter for high-power energy storage.

Sign in / Sign up

Export Citation Format

Share Document