Category: Analysis, Design and Implementation of a High Efficiency Multilevel Converter for Renewable Energy Systems

Inverter improvement

Further inverter no-load reduction can be mainly achieved by modifying the multiple­winding transformer design. The simplest way to reduce the transformer no-load consumption is to increase the number of turns in its primary. In this case, if a same core is used, then coil wire area must be decreased in order to fit the same […]

Economical viability

Table 7.2 shows the average price of some commercial inverters that were obtained thought internet from diverse worldwide sellers. Table 7.2 – Prices of selected commercial inverters. Inverter Power Mean Price [€]* €/W Phoenix 48/3000/35 3000 2.800 0.93 Studer C3548 3500 1.800 0.51 Xantrex SW2548 2500 1.800 0.72 SMA Sunny Island 3324 3300 2.300 0.70 […]

Final Analysis

7.1 Comparison with other inverters A summary of the main characteristics of the implemented prototype and some commercial inverters is shown in table 7.1. Table 7.1 – Specification data of some commercial converters and implemented prototype. No Inverter Vin [Vdc] Vout [VRMS] Power [VA] npk [%] No-Load [W] Surge Power Surge Current Weight [kg] 1 […]

Non-conventional experiments

The maximum allowed THD of 5% has imposed a limit to the hold-on-at-zero interval so all presented experiments were done with a fixed value of 0.7 ms. However, if the hold-on-at-zero interval is increased, then it is possible to reduce de no-load consumption and consequently increase efficiency at light loads. On the other hand, the […]

Efficiency characteristic

In this section the efficiency characteristic of the proposed converter is investigated according to the variation of input voltage, output voltage, temperature and type of load. 400 1 20 Because the operation frequency is low, losses are mainly attributed to conduction losses in cables, protection devices, connections, switches and transformer. Figure 6.37 shows the conduction […]

Characteristic curves

6.7.1 No-load consumption Figure 6.34(a) shows the no-load consumption as a function of the input voltage. As can be seen, the input voltage has great influence in the no-load consumption and its characteristic looks like an exponential curve. This fast increase can be associated with the increase of the transformer no-load losses as its primary […]

Battery-charge-mode using Sunny Boys

The proposed converter is bi-directional and this feature can be used to charge the battery bank if its output is connected to a power source with current source characteristic. This type of operation was realized by using solar panels and grid inverters, using the configuration shown in figure 6.31. The prototype was connected to 2 […]

Startup of loads

In practice, most loads do not act like pure resistance, inductance or capacitance. Non linear characteristic and high startup currents are usually presented by real loads, such as refrigerators, incandescent and fluorescent lights, single phase motors, computers, and general electronic apparatus. The capability of the proposed inverter to operate such loads is demonstrated in this […]