MULTILEVEL INVERTERS ARE THE ALTERNATIVE FOR MEDIUM VOLTAGE APPLICATIONS. WITHIN THIS TYPE OF INVERTERS ARE THE ASYMMETRIC INVERTERS, WHICH HAVE DIFFERENT VALUES IN THEIR DC VOLTAGES. THE DC VOLTAGE RATIOS CAN BE OF THE TRINARY OR BINARY TYPE, THE FIRST BEING THE MOST DOCUMENTED, WITH WHICH AN AC VOLTAGE OF 3 N = 27 LEVELS IS OBTAINED, USING N = 3 INVERTERS IN CASCADE AND NLM MODULATION, WHICH GENERATES A FLOW OF POWER FROM THE LOAD TO THE INVERTERS (REGENERATION). IN THIS PAPER WE ANALYZE TWO TYPES OF NON-REGENERATIVE SINGLEPHASE ASYMMETRIC INVERTERS, OF 15 AND 27 LEVELS, WHERE THEIR QUALITY OF OUTPUT VOLTAGE WAVEFORM (THD) AND EFFICIENCY ARE ANALYZED. THE LATTER WILL BE FOCUSED ON THE COMMUTATION AND CONDUCTION LOSSES IN THE SEMICONDUCTORS. IN SUCH A WAY TO BE ABLE TO MAKE A CHOICE OF THE INVERTER CONSIDERING THESE TWO INDICES. FINALLY TO CHECK WHAT IS PROPOSED, SIMULATION RESULTS ARE SHOWN.

IN PREVIOUS WORK, IT WAS PROPOSED TO USE MULTILEVEL CURRENT SOURCE CONVERTERS TO INCREASE THE CURRENT CAPACITY AS WELL AS IMPROVE THE HARMONIC PROFILE OF MEDIUM VOLTAGE AND HIGH CURRENT DRIVES. RECENT PUBLICATIONS SUGGEST THAT BOTH (A) ITS INTRINSIC BOOSTER CHARACTERISTICS AND (B) ITS EASY WAY TO HANDLE INDEPENDENT DC SOURCES OPERATING IN PARALLEL MAKE THIS TOPOLOGY AN ATTRACTIVE ALTERNATIVE FOR THE DIRECT CONNECTION OF PHOTOVOLTAIC PLANTS TO THE GRID. FURTHERMORE, STAGGERED OPTIMIZED PATTERNS WERE PROPOSED TOGETHER TO MODULAR TOPOLOGIES REGARDING THE IMPROVEMENT ON HARMONIC PROFILE OF INJECTED CURRENTS TO THE GRIDS. ONE OF THESE TECHNIQUES ARE THE STAGGERED SELECTIVE HARMONIC ELIMINATION. AN ALTERNATIVE IS THE STRAIGHTFORWARD OPTIMIZATION FOR REDUCE THE ERROR AMONG A TIME-BASED REFERENCE AND THE MODULATED CURRENT PATTERN. THIS WORK PRESENTS A COMPARISON BETWEEN THREE OPTIMIZED PATTERNS FOR THE OPERATION OF STAGGERED PATTERNS IN CURRENT SOURCE CONVERTERS, FOR BOTH SYMMETRIC AND ASYMMETRIC CASES. THEORETICAL RESULTS THAT ARE VALIDATED BY SIMULATION ARE PRESENTED.

THE GENERATION OF COLD PLASMA IS APPLIED TO DIFFERENT PROCESSES AS GRINDING OF ROCKS, HARDENING OF METALS AND STERILIZATION OF FOOD. TO OBTAIN COLD PLASMA IN A VACUUM CHAMBER, IT IS NECESSARY TO PARTIALLY IONIZE THE GAS BETWEEN THE ELECTRODES, GENERATING HIGH VOLTAGE PULSES OF THE ORDER OF MICROSECONDS. THE REPETITION FREQUENCIES OF THESE PULSES DEPEND ON THE SPECIFIC APPLICATION. THE DESIGN OF THE POWER SOURCES CAN INCLUDE A SYNTHETIC PULSE FORMATION LINE (PFN) TRIGGERED OR USING VACUUM VALVES OR STATIC CONVERTER ARRAYS. IN LABORATORY APPLICATIONS WHERE APPLICATIONS FOR COLD PLASMA ARE STUDIED, IT IS CONVENIENT TO DESIGN A POWER SOURCE THAT CAN PROVIDE DIFFERENT LEVELS OF VOLTAGE AND CURRENT, WITH DIFFERENT PULSE WIDTHS, REPETITION FREQUENCIES, AS WELL AS SYSTEMS FOR PLASMA CHARACTERIZATION, AND AUTOMATION. OF EQUIPMENT OPERATING PROCEDURES FOR SAFETY. THIS WORK PRESENTS THE DESIGN OF A PULSATING SOURCE AND ITS ATTACHED SYSTEMS USING LOWCOST COMPONENTS, CONTRASTING THE THEORETICAL RESULTS WITH EXPERIMENTAL RESULTS.

THIS WORK DEALS WITH A DISTRIBUTION STATIC SYNCHRONOUS COMPENSATOR (D-STATCOM) BASED ON A CURRENT-SOURCE CONVERTER FOR LOW AND MEDIUM VOLTAGE DISTRIBUTION SYSTEMS, SPECIFICALLY SMALL AND MEDIUM MANUFACTURES INDUSTRIES WHICH ARE FINED IF THE DISPLACEMENT POWER FACTOR IS BELOW GIVEN LIMITS. THE D-STATCOM IS ANALYZED USING ITS MATHEMATICAL MODEL, SHOWING THE STRONG RELATION OF THE D-STATCOM POWER LOSSES AND ITS DC CURRENT LEVEL. USING THE OPERATING REGION OF THE D-STATCOM, AN OPERATING SUB-REGION IS DEFINED SUCH THAT THE MINIMUM DC CURRENT IS USED FOR A REQUIRED REACTIVE COMPENSATION, WHICH LEADS TO REDUCING THE OPERATING LOSSES IN THE D-STATCOM. ALSO, SELECTIVE ELIMINATION HARMONIC IS USED TO MODULATE THE EQUIPMENT TO REDUCE THE SWITCHING FREQUENCY WHILE ENSURING A DESIRED CURRENT QUALITY IN THE D-STATCOM INPUT. AS A RESULT, A SIMPLE CONTROL STRATEGY IS PROPOSED THAT USES A FIXED MODULATION INDEX WHILE A PHASE CONTROL REGULATES THE DC CURRENT TO THE LOWEST VALUE REQUIRED FOR REACTIVE POWER COMPENSATION. MATHEMATICAL ANALYSIS JOINTLY WITH SIMULATED AND EXPERIMENTAL RESULTS CORROBORATES THE PROPOSAL, SHOWING THAT IT IS POSSIBLE TO ACHIEVE A SUITABLE COMPENSATION CAPABILITY FOR IMPROVING THE EFFICACY OF THE STATCOM.

COUPLED-INDUCTOR BUCK-BOOST DC-DC SWITCHING CONVERTER HAS EMERGED AS AN ALTERNATIVE TO MANAGE POWER IN SEVERAL HYBRID SYSTEM ARCHITECTURES. THIS IS DUE TO FEATURES SUCH AS A NONINVERTING VOLTAGE STEP-UP AND STEP-DOWN CHARACTERISTIC, HIGH EFFICIENCY, WIDE BANDWIDTH, AND THE POSSIBILITY TO REGULATE ITS INPUT OR OUTPUT CURRENTS AS HAS BEEN REPORTED IN PREVIOUS WORKS. ALL OF THEM ARE BASED ON A SMALL-SIGNAL LINEARIZED MODEL AROUND AN OPERATING POINT. IN THIS ARTICLE, A MODEL PREDICTIVE CONTROL STRATEGY IS PROPOSED TO INCREASE THE OPERATION POINT DOMAIN. THE PROPOSAL CONSISTS IN THE USE OF THE MATHEMATICAL MODEL OF THE SYSTEM IN DISCRETE TIME TO OBTAIN THE OPTIMAL SWITCHING STATE TO BE APPLIED IN THE CONVERTER BASED ON A COST FUNCTION OPTIMIZATION, WHICH SIMULTANEOUSLY IMPROVES THE CURRENT TRACKING AND REDUCES THE CONVERTER POWER LOSSES. EXPERIMENTAL RESULTS VALIDATE THE PROPOSAL DEMONSTRATING THAT THIS IS A GOOD ALTERNATIVE FOR THE CONTROL OF THIS KIND OF POWER CONVERTERS.

FINITE CONTROL SET MODEL PREDICTIVE CONTROL CAN BE APPLIED TO A POWER CONVERTER IF THERE IS AN ACCURATE EXISTING MODEL OF THE CONVERTER. THE BEST RESULTS WILL BE ACHIEVED IF AND ONLY IF THE PARAMETERS AND VARIABLES THAT MAKE UP THE SYSTEM ARE PROPERLY ESTIMATED. IF THIS IS NOT THE CASE, THE PREDICTIONS MADE USING THESE STRATEGIES MAY BE ERRONEOUS AND CAUSE PROBLEMS, SUCH AS STEADY-STATE ERROR WITH RESPECT TO THE ASSIGNED DESIRED REFERENCES. THIS PAPER PRESENTS A PREDICTIVE CONTROL STRATEGY WITH INTEGRAL ACTION THAT COMPENSATES FOR THE DIFFERENCES BETWEEN THE ESTIMATED MODEL AND THE INVERTER WITH THE OBJECTIVE OF ACHIEVING A ZERO STEADY-STATE ERROR WITHOUT REQUIRING EXTERNAL LOOPS OR STATE OBSERVERS. THE PROPOSED STRATEGY IS TESTED ON A SINGLE-PHASE Z-SOURCE INVERTER SO AS TO EVALUATE THE ERROR IN BOTH THE AC AND DC CONTROLLED VARIABLES WITH RESPECT TO THEIR REFERENCES TO THEIR COSIGNS. THE EXPERIMENTAL RESULTS CONFIRM THAT THE PROPOSED STRATEGY ACHIEVES A ZERO ERROR IN THE STEADY STATE WHILE MAINTAINING

THE PRESENT WORK PRESENTS THE STATE OF ART REVISION FOR THE CHILEAN LEGISLATION, NORMS AND GUIDES TO CARRY OUT A PHOTOVOLTAIC INSTALLATION AT THE UNIVERSIDAD DEL BÍO-BÍO. THE CHILEAN SOLAR POTENTIAL WITH RESPECT THE REST OF THE WORLD, HIGH-LIGHTING CHILE AS THE WORLD LEADER IN SOLAR RESOURCE AVAILABILITY, WITH THE HIGHEST RADIATION RATES, EVEN BIGGER THAN COUNTRIES AS GERMANY, SPAIN, CHINA, UNITED STATES, WHICH HAVE A SIGNIFICANT AMOUNT OF PHOTOVOLTAIC (PV) ENERGY INSTALLED. TO ATTAIN A PV INSTALLATION IT IS NECESSARY TO CARRY OUT AN ENERGY CONSUMPTION STUDY, CONSIDERING THE INVOICES OF THE ELECTRICAL CONSUMPTION AND THE DAILY CONSUMPTION CURVE, IN ORDER TO DIMENSION THE NUMBER OF PV MODULES TO BE INSTALLED. IN ADDITION, THE PV CURVES ARE STUDIED TO EXTRACT THE MAXIMUM POWER FROM THE PV MODULES BY THE USE OF ALGORITHMS CAPABLE TO WORK INTO THE WHOLE SYSTEM OPERATING REGION, OPTIMIZING THE ENERGY INJECTION TO THE GRID AND/OR BATTERIES. FINALLY, AN ECONOMIC STUDY IS PRESENTED WHERE ECONOMICS TOOLS SUCH AS THE NET PRESENT VALUE (NPV) AND INTERNAL RATE OF RETURN (IRR) ARE EMPLOYED TO SHOW THIS PROJECT FEASIBILITY.

THIS PAPER PRESENTS THE COMPARISON BETWEEN THREE CONTROL STRATEGIES: A PID BASED CONTROL, THE GAINS SCHEDULE PID BASED CONTROL AND A COMBINATION OF PID AND STATES FEEDBACK BASED CONTROL FOR A DC-DC POWER CONVERTER. THE DC-DC CONVERTER IS USUALLY EMPLOYED ON RENEWABLES ENERGIES TO PUMP THE VOLTAGE UP TO STANDARD VALUES ON THE GRID COUPLE POINT, WHICH IN THE CASE OF CHILE IS 220V RMS AND 50HZ; OR TO BE USED ON VOLTAGE REGULATORS, WHICH NEEDS TO MAINTAIN THE VOLTAGE TRACKING A REFERENCE INDEPENDENTLY OF THE INPUT VOLTAGE SUPPLY. THE MAIN OBJECTIVE IS TO ACHIEVE CONTROLLABLE SYSTEM INTO THE WHOLE POWER CONVERTER OPERATING REGION, WITH SIMILAR DYNAMIC RESPONSES. TO CORROBORATE THE MATHEMATICAL STUDY AND THE PROPOSED DESIGN, SIMULATIONS TESTS WERE PERFORMED IN SIMULINK/MATLAB ENVIRONMENT SHOWING EVERY STRATEGY STRENGTHS TO FAIRLY COMPARE THE RESULTS UNDER DISTURBANCES AND REFERENCES CHANGES.

A SERIES ACTIVE COMPENSATOR BASED ON SINGLE-PHASE CURRENT SOURCE CONVERTERS IS STUDIED. THE PROPOSAL HAS TWO ADVANTAGES; FIRST, IT REQUIRES JUST A FIRST ORDER CAPACITIVE FILTER ON THE AC SIDE AS COMPARED TO THE SECOND ORDER LC FILTER NEEDED BY VOLTAGE SOURCE BASED TOPOLOGIES. AS A RESULT, SAGS AND SWELLS CAN BE COMPENSATED WITHOUT THE HASSLE OF OSCILLATIONS AT THE LOAD VOLTAGE SIDE; SECOND, AN EXTERNAL CONTROL LOOP IS ADDED TO REGULATE THE DC CURRENT VALUE. THIS TECHNIQUE IS BASED ON THE CONVERTER MODULATING VECTOR MAGNITUDE CONTROL, AND IT GUARANTEES THE SYSTEM OPERATION AT MINIMUM DC LINK CURRENT, WHICH MINIMIZES THE CONDUCTING AND COMMUTATING LOSSES. THE TOPOLOGY AND CONTROL SCHEME CAN BE EXTENDED TO MULTI-LEVEL CONFIGURATIONS, WHICH MAKES THE ARRANGEMENT SUITABLE FOR MEDIUM TO HIGH VOLTAGE APPLICATIONS USING STANDARD SEMICONDUCTORS.

POWER ELECTRONIC LOADS ARE SOURCES OF UNWANTED HARMONIC AS WELL AS REACTIVE POWER. PASSIVE POWER FILTERS AND ACTIVE POWER FILTERS ARE A SUITABLE SOLUTION FOR THOSE POWER QUALITY ISSUES. IF ACTIVE POWER FILTERS ARE USED, THEN IT CONTROLS SYSTEMS NEED TO MEASURE OF HARMONIC AND REACTIVE POWER TO COMPENSATE IT THROUGH A CONTROLLED CURRENT OR VOLTAGE SOURCE. THUS, IT IS IMPORTANT TO DETERMINATE BOTH, FUNDAMENTAL COMPONENT AND HARMONICS COMPONENTS FOR THE ELECTRIC VARIABLE TO BE COMPENSATED. FURTHERMORE, IF THE DESIGN USES A MODULAR APPROACH WITH SEVERAL ACTIVE FILTERS COMPENSATING DIFFERENT HARMONICS THEN THE VALUE OF EACH HARMONIC IN REAL TIME IS REQUIRED. THIS WORK PRESENTS A METHOD TO FIND THE HARMONIC COMPONENTS OF SIGNAL BASED ON A ROBUST PLL WHERE A SINUSOIDAL BASE IS BUILT AND USED TO FIND THE FOURIER COEFFICIENTS FOR THE SELECTED HARMONICS. SIMULATED AND EXPERIMENTAL RESULTS ARE PRESENTED TO VALIDATE THE THEORETICAL CONSIDERATIONS.

THIS WORK SHOWS THE USE OF THE OPERATING REGION OF A D-STATCOM BASED ON CURRENT-SOURCE INVERTERS TO DEFINE ITS OPERATING POINT AND ITS LC FILTER. FIRST, A CURRENT-SOURCE STATCOM MODEL IS DEFINED TO COMPUTE ITS OPERATING REGION AND OBTAIN A RELATION BETWEEN REACTIVE POWER COMPENSATION AND THE DEVICE POWER LOSSES. BECAUSE THIS RELATIONSHIP DEFINES THE LOSSES COSTS OF THE REACTIVE POWER COMPENSATION, THIS RELATION IS USED TO DEFINE A METHODOLOGY TO GET AN OPERATING POINT AND DESIGN THE LC AS A FUNCTION OF THE DESIRED COST FOR NOMINAL POWER COMPENSATION. THE METHODOLOGY IS TESTED IN THE DESIGN OF A 125KVA/380V DISTRIBUTION GRID, WHERE SIMULATION RESULTS CORROBORATE THE ANALYSIS, INCLUDING CHANGES FROM ONE OPERATING POINT TO ANOTHER, IN OPEN LOOP, TO SHOW THE COMPENSATION CAPABILITIES, THE POWER TOPOLOGY EFFORT AND THE GRID MAINS VARIABLES WITH COMPENSATION.

THIS PAPER EXPLAINS THE DEVELOPMENT OF A WIRELESS POWER TRANSFER SYSTEM, WHEREBY INDUCTIVE COILS AND POWER CONVERTERS, CHARGE AN EMBEDDED ENERGY-STORAGE SYSTEM IN A MICROINVERTER, USING A PHOTOVOLTAIC PANEL. A DETAILED ANALYSIS OF THE DESIGN, IMPLEMENTATION AND CONTROL OF A STATION FOR BATTERY CHARGING, USING A PV PANEL OF 35[W] IS DEVELOPED. AN INDUCTIVE-COUPLING LINK IS USED, WHICH CONSISTS OF TRANSMITTING ELECTRICAL POWER FROM A POWER SOURCE TO A LOAD USING A MAGNETIC FIELD. FINALLY, THE RESULTS OBTAINED IN SIMULATIONS FROM PSIM SOFTWARE AND THE EXPERIMENTAL IMPLEMENTATION ARE CONTRASTED, SHOWING A 12[V] BATTERY WHICH EMULATES THE EMBEDDED ENERGY-STORAGE SYSTEM TO PROVE THE CONCEPT. THEN, THE BATTERY IS CHARGED WITH A CONTROLLED CURRENT OF 300[MA].