METHOD AND APPARATUS FOR EXTRACTING ELECTRICAL ENERGY FROM PHOTOVOLTAIC MODULE

摘要

The present invention relates to the field of energetic, more particularly to generation of photovoltaic direct current followed by its transformation into alternating—AC—or direct—DC—currents. The invention is applicable to photovoltaic power plants and setups connected either to local AC electrical power distribution systems or to energy storage systems, which apply the known from the prior art devices. According to the claimed method selection electricity from photovoltaic module (1) by which the energy of solar radiation is converted to an electrical signal, pre-store energy electrical signal by using capacitor (2) not less than 0.15 Farad, charged to the maximum power voltage photovoltaic module that determined from the current-voltage characteristics, normalized voltage electrical signal using a DC/DC converter and accumulate. At the same time selected energy is converted to alternating current through DC/AC inverter (3) and continuously is served into a AC local grid (6) while power DC/DC converters and (or) DC/AC inverter installed on for at least one of three levels that is not less than the power of photovoltaic module with a minimum insolation, the maximum insolation and for at least one intermediate insolation.

主权项

1. The method for electrical energy take-off from a photovoltaic module in which on the basis of current-voltage characteristics of photovoltaic module (PVM) connected in parallel to the input of either DC/DC converter or DC/AC inverter, with a capacitor connected to them in parallel and a means for voltage measurement, connected with the control module of DC/DC converter or DC/AC inverter, the following parameters are measured: i) voltage UB at the maximum power point (MPP) of PVM under maximal level of insolation, ii) the minimum voltage U0 which is not less as 5% of the open circuit voltage of PVM in the case of DC/DC converter or not less as 25% in the case of DC/AC inverter, iii) voltage U1 at the MPP of PVM under at least one intermediate level of insolation between its maximal and minimal values; then the DC/DC converter or the DC/AC inverter is adjusted to one of the power levels (Px), which is not less as the maximal power of PVM under either minimal insolation (P0), either maximal insolation (PB), or at least one intermediate insolation (P1) between minimal and maximal insolation accordingly; at arising and increasing insolation, energy from PVM is transferred to capacitor and collected there continuously; characterized in that, voltage on the capacitor (UC) is measured simultaneously, and when UC achieves the value U0, the means for voltage measurement sends a signal to switch the control module on; when UC achieves the value U1 the control module sends a signal to the DC/DC converter or the DC/AC inverter to operate at the power level P1; when UC achieves the value UB the control module sends a signal to the DC/DC converter or the DC/AC inverter to operate at the power level PB; and vice versa, at decreasing insolation, the DC/DC converter or the DC/AC inverter consumes energy collected by the capacitor; when UC drops down to the value U1 the control module sends a signal to the DC/DC converter or the DC/AC inverter to operate at the power level P1; when UC drops down to the value U0, the means for voltage measurement sends a signal to the DC/DC converter or the DC/AC inverter to operate at the power level P0; when UC drops down to the lower value than U0, the means for voltage measurement sends a signal to switch the DC/DC converter or the DC/AC off.