Tatsuaki Ambo

Relevant aspects in designing a photovoltaic inverter for industrial and commercial applications

This paper presents design considerations for grid connected photovoltaic inverters intended for use in industrial and commercial applications. Important aspects such as efficiency, reliability, construction constraints, control, standards and grid codes compliance are discussed. On the other hand, characteristics of a 600 V system based on Japanese standards and a 900 V system based on IEC standards are compared and discussed. Experimental data for a 2 kW down-scaled prototype are presented along with test data for 250 kW isolated and transformerless units built under Japanese standards and IEC standards.

Development of a compact, complete shield PCS for wind turbine generators

A compact, complete shield power conditioning system (PCS) has been developed for wind turbine generators. It has high energy density, high reliability and IP 54 protective class. The PCS employs the latest converter technology comprising the latest IGBT with high cooling efficiency and the latest film capacitor instead of electrolytic capacitor. The PCS was verified at full load condition in the run-back test bench and the characteristic of output reactive power was also verified. The characteristic of the sensor-less vector control for generator and the grid connecting control were verified with the scale-down model PCS. Low voltage ride through (LVRT) function was verified at the analysis and the scale-down model PCS test.

Development of the large capacity PCS for the wind turbine

Abstract – A large capacity PCS applied to PMSG (permanent magnet synchronous generator) of wind turbine has been developed. This PCS is characterized by snubber-less circuit, as a result, it is accomplished miniaturize and high reliability. To obtain not only a maintenance-free but also robustness for dc over voltage at the over speed of the wind turbine, the film capacitor which possesses a high energy density is adopted for a dc-circuit. Three kinds of tests were carried out. First, the IGBT shut-off test was examined under the worst condition for this PCS. This test result showed that the IGBT surge voltage was less than an allowable limit. Second, the method of the run-back test was established, as the load which is actually same condition is given for the PCS. The PCS was operated stably during heat run test. Third, the characteristic test for the reactive power was carried out with run back test bench, and this test verified the reactive power of grid was able to control with tracking reference from the system controller. As a result of these tests, the PCS achieved satisfactory performance for the PMSG of the wind turbine.