| 摘要 |
PURPOSE:To optimally and accurately protect or control an inverter by reading out an internal time and sinusoidal approximate data from memory means and forming a PWM signal. CONSTITUTION:An interval time corresponding to frequency is previously memorized in interval time memory means 2. A carrier pulse number corresponding to the frequency is memorized previously in carrier pulse number memory means 15. A plurality of amplitudes of sinusoidal wave approximate data corresponding to a load state is memorized in amplitude memory means 16. A plurality of sets of sinusoidal approximate data corresponding to the carrier pulse number and amplitude of one period are previously memorized in sinusoidal wave approximate data memory means 17. The data read out from these memory means are inputted through interval time inserting means 14, synchronizing means 22 to PWM signal forming means 23, which forms a PWM signal. |
