Singles or doubles?

Power Systems International has introduced its new EL series of solid state industrial frequency converters with 400Hz output for point of use application.

Suitable for both military and civil usage, these compact frequency converters can be supplied in single module or in parallel configuration to provide 400Hz power through a ring main distribution system for individual point of use power outlets for service installations in workshops, hangars and in hard shelters.

If desired, the frequency converters can be supplied with a second output 28VDC DC for helicopter starting and for auxiliary generator starting duty: they can also be installed outdoors in all weather environments on offshore helipads and landing platforms.

In single module guise, the 400Hz point of use application converters can be used for installation adjacent to aircraft parking positions or fitted to the passenger loading bridges; alternatively, they can be floor mounted in workshops, hangars or where a centralised system with distribution would not be a cost-effective alternative consideration. This point of use power unit has an obvious application in airport expansion projects where a pier is added to a passenger terminal.

These converters are simple to connect to normal power sources and they can be located close to the aircraft, without the need for line drop compensators, supplementary transformers, specialised pits, ducts or any other apron excavation work.

The frequency converters can also be provided with telemetering, a remote monitoring feature that allows full observation of critical functions and operational behaviour: this permits interfacing with the connected load and the power consumption at the point of use. Moreover, Power Systems International is able to offer design consultancy and project management for the application of frequency converter systems and power distribution for connecting into existing or new apron pit systems. It also supplies automatic cable handling and retrieval systems for passenger loading bridge mounting or a flexible, Z fold crocodile system for use at the apron point of aircraft parking and ground service.

The EL series 400Hz frequency converters are available in capacities of 2kVA to 25kVA, with single phase output, and from 7.5kVA to 300kVA with three phase output. The input stage can be 6 or 12 pulse rectifiers; the inverters use IGBT PWM commutating technology and the indoor maintenance hangar versions have ingress protection P21, whilst the outdoor versions benefit from IP54 protection.

A new dual 2 x 90kVA version frequency converter system is now available. This compact unit contains a 12 pulse rectifier and two separate 90kVA inverters with two separate outputs and connections for feeding a wide-bodied aircraft that requires external power from two input cables. The output of each inverter can be switched to deliver power through either of the dedicated cables or the outputs can be connected in parallel.

The control logic detection circuit on all of the EL series converters synchronises the output to the onboard aircraft 400Hz service and thus ensures there is a continuous transfer of power to the aircraft power distribution system when the converter is connected.