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World's First Large-Capacity Static Uninterruptible Power Supply (UPS)

Large-capacity power supply was made possible by the development of a power semiconductor device called a thyristor.

World's First Large-Capacity Static Uninterruptible Power Supply (UPS)

Toshiba laid the foundation for the development of the uninterruptible power supply (UPS) systems that support today's highly sophisticated information-based society.

In the past, rotating motor generators (MG sets) were used to provide a stable power supply for communication equipment and information processing systems, including computers. In 1964, Toshiba commercialized its first static UPS (5 kVA capacity), making use of a power semiconductor device called a thyristor. Three years later, in 1967, the company released a large-capacity UPS (200 kVA). This equipment was utilized in the air traffic control system at Haneda International Airport in Tokyo, where even a onesecond power outage could result in disaster.

Basically, a UPS receives commercial AC power and converts it into DC power through a silicon rectifier. The power is further converted into stable AC power by a thyristor inverter and supplied to the load system. At the same time, a battery is charged in order to supply DC power to the thyristor inverter, so that the inverter can continue to supply AC power to the load in the event of commercial power failure. In addition to making use of commercial power, a UPS is equipped with an emergency in-system power generator. The generator produces AC power in order to supply system operations in place of the commercial power supply, before the battery runs out of power.

At the time, the device was referred to as a constant voltage and constant frequency (CVCF) unit because it provided stable voltage and frequency. Today, it is called an uninterruptible power supply, or UPS for short, in order to emphasize its ability to supply power uninterruptedly. Japan was moving rapidly toward the computer era at the time the UPS was developed, and computers were becoming faster, increasingly sophisticated, and more widespread. Under these circumstances, stable and highly reliable UPS systems became essential for the protection of computers from power failure. In the 1970s, a number of technologies were developed that further enhanced the reliability of UPS systems. These technologies allowed for practical application of an uninterruptible switching device to supply power to the load uninterruptedly as a bypass power supply. It also allowed for the development of a high-speed thyristor interrupter that used a parallel redundancy system made up of several UPS units, and made possible the development of high-performance, highly reliable system control technologies. As a result, Toshiba was able to launch the TOSNIC (Toshiba noninterruptible converter) series, available in capacities from 50 to 300 kVA.

To convert DC power into AC power, the converter used a McMurray inverter incorporating a 600 V-300 A highspeed thyristor, a commutating reactor, and a commutating capacitor. Later, after a self-arc-suppression type power semiconductor device was developed, gate turn-off thyristor (GTO)-based inverters and converters were put to use, followed by insulated gate bipolar transistor (IGBT)-based inverters and converters. Thanks to the development of power semiconductor devices, UPS systems realized high efficiency, high functionality, and high reliability and have responded well to the needs of society. In the late 1980s, an online computer center equipped with a 13,000 kVA UPS was established. Today, UPS systems have become indispensable in supplying uninterrupted power for important systems at data centers, control centers, and semiconductor manufacturing sites.

TOSNIC

TOSNIC

TOSNIC

TOSNIC

TOSNIC 200kVA

TOSNIC 200kVA

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