NOVELTY - The apparatus has an electric power combining unit (100) to measure electrical characteristic values of source and transfer measured values to a central control unit. The source terminals are connected in serial or parallel combination according to measured results. The impedance between source and load terminals that are connected in series or in parallel are matched. A voltage converting unit (200) which is connected to the load terminal, converts electric power signal collected by electric power combining unit to generate power supply voltage.    USE - Electric power conversion apparatus in energy harvesting system for producing large electric power such as photovoltaic power generation, tidal power generation and wind power generation.    ADVANTAGE - Since the electric power conversion apparatus adjusts and couples impedance to maximally use the available electric power of each source, the maximum electric power can be generated effectively. Since the electric power conversion apparatus adjusts a connection structure between the sources based on the electrical characteristic values of each source and adjusts impedance of the load including loads according to the connection structure, the inefficiency at the time of the electric power conversion is eliminated effectively. The electric power capable of driving and charging electronic devices from various types of energy sources even at locations where electricity is absent is obtained effectively by collecting several small electric power sources to obtain the increased electric power.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an electric power conversion method in an energy harvesting system.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the electric power combining unit.    Electric power combining unit (100)    Input select unit (110)    Serial and/or parallel combining unit (120)    Voltage and/or current measuring unit (130)    Voltage converting unit (200)