MANAGEMENT OF A PHOTOVOLTAIC POWER SYSTEM BY A POWER CONDITIONING UNIT (PCU) CALCULATING THE MAXIMUM POWER POINT (MPPC)

摘要

The present invention relates to a power conditioning unit (1) which manages a power system consisting of n identical solar panels (2), a battery (3) and a utilization network (4). This unit is modular represented in fig1 is composed of 2 types of power regulators: a non-dissipative shunt (5) formed of n shunts, one per panel, a charger-discharger bidirectional battery (6), that is to say say a regulator capable of both charging or discharging a battery and a calculation module (7). This module is able to calculate the maximum power point of solar panels, called MPP, with current and voltage information, and generate a reference voltage, image of the MPP voltage, and transmit it the power regulators (8) for regulating the VMPP voltage (9) which is distributed to the utilization network. The calculation of the MPP voltage by the MPPC-uP (7) module is the result of a mathematical process, solving a system of 3 equations with 3 unknowns. This calculation is fast, a few microseconds, accurate, and the MPP voltage does not vary if the illumination conditions do not change. It allows a constant follow-up of the evolution of the conditions of exposure to the sun. This calculation involves knowing 3 parameters. One of them, the current of short-circuit of a panel is immediate: it is the current that provided the panel which is shortcircuit by a shunt module, here the module 1 (10). The knowledge of the other 2 parameters requires the measurement of the coordinates, current and voltage, of a point M of the electrical characteristic of a panel, in nominal operation and of 2 points in forced mode (very strong power which involves the discharger of drums).