Uniterruption power supply unit, changer and parallet work type changer

Abstract

An uninterruptible power systems each are constituted by an inverter circuit and an inverter circuit control device. The inverter circuit control device includes a PWM control signal generating means. The PWM control signal generating means generates a PWM control signal so as to gradually reduce an output voltage of the inverter circuit as supply active power increases and until a judging means judges that the supply active power has reached a predetermined level and so as to reduce the output voltage at a reduction ratio increased as compared with before to keep it from falling into an overload condition when the judging means judges that the supply active power has reached the predetermined level. The parallel operation-type uninterruptible power system capable of preventing one of uninterruptible power systems from being extremely increased in load sharing ratio without having to operate each uninterruptible power system while watching operation of the remaining uninterruptible power systems.

Description

technical field [0001] The invention relates to a non-interruptible power supply device, a parallel working type non-stop power supply device, a conversion device, and a parallel working type conversion device. Background technique [0002] In the conventional uninterruptible power supply device, that is, in the uninterruptible power supply device of the so-called normal conversion method, the commercial power supply converts the DC power obtained by converting the AC power from the commercial power supply into DC power even under normal conditions. It is converted into AC power and output to the load. When the commercial power supply fails, the DC power from the battery is converted into AC power and output to the load. Moreover, the uninterruptible power supply device includes: a conversion circuit for power conversion; a conversion circuit control device including a PWM control signal generating part for generating a PWM control signal; the PWM control signal is used to: ...

AI Technical Summary

Problems solved by technology

[0005] However, if the above-mentioned prior art of connecting a plurality of uninterruptible power supply devices in parallel to work is used, each uninterruptible power supply device must be operated according to the output of other uninterruptible power supply devices, so it is necessary to separately There is a problem that cannot be solved simply by connecting multiple uninterruptible power supply devices in parallel by providing a circuit for interconnecting each uninterruptible power supply device.

Moreover, even if the technology shown in Japanese Patent Publication No. 6-40704 is used, it can only control crosstalk, and cannot solve the problem of extremely increasing the load sharing of one converter.

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