PARALLEL CONTROLLER OF ONLINE UNINTERRUPTIBLE POWER SUPPLY UNIT

摘要

PURPOSE: A parallel controller of an online uninterruptible power supply unit is provided to form a load assignment control algorithm by compensating the power deviation according to a synchronous coordinate axis variable. CONSTITUTION: A parallel controller of an online uninterruptible power supply unit includes a phase synchronization unit(10), a voltage detection unit(12), a phase detection unit(14), low pass filters(22,24), a reference current setup unit(26), the first mixer(28), error detectors(30,32), the second mixers(38), an amplification unit(42), a pulse width modulation unit(44), an inverter(46), and the second power supply unit(48). The phase synchronization unit(10) synchronizes a phase of the third power. The voltage detection unit(12) detects an output voltage of the third power. The phase detection unit(14) detects the phase according to the first and the second input signals of the phase synchronization unit(10) and the voltage detection unit(12). The low pass filters(22,24) are used for forming the effective power or the ineffective power by means of outputs of the phase detection unit(14). The reference current setup unit(26) sets up the current of the low pass filters(22,24) as the reference current. The first mixer(28) is used for mixing the current of the low pass filters(22,24) with the reference current of the reference current setup unit(26). The error detectors(30,32) are used for detecting the power deviation by using the voltage of the phase detection unit(14) and the current of the first mixer(28). The second mixers(38) is used for mixing the output voltages of the error detectors(30,32). The amplification unit(42) amplifies the voltages of the second mixers(38). The pulse width modulation unit(44) changes the pulse width according to the amplitude of an output signal of the amplification unit(42). The inverter(46) is used for inverting the DC power of pulse width modulation unit(44) to the AC power. The second power supply unit(48) supplies the second power.