Frequency Converters, Motor Drives & Military UPS Systems

At 400 Hz, transformers and motors can be smaller and lighter for the same power, which is why many shipboard, radar and weapon-system subsystems are designed for a 400 Hz supply. Site and camp grids deliver 50 or 60 Hz, so a static frequency converter rebuilds the supply at 400 Hz electronically, without a motor-generator set. The 115/200 VAC 400 Hz Static Frequency Converter has its output voltage and frequency requirements defined to MIL-STD-1399-300B for shipboard use, and its output is adjustable between 60 and 400 Hz. Where 400 Hz and 60 Hz loads run side by side, the PowerGuard Outdoor and the AC-AC Frequency Converter Transformer System each provide 2 × 400 Hz and 5 × 60 Hz outputs at 12 kVA; for low-power electronics that also need 28 VDC, the TPS-115 delivers 3-phase 115 VAC 400 Hz (600 VA) alongside three isolated 28 VDC outputs.

For 60 Hz and 400 Hz at the same time on separate channels outdoors, the PowerGuard Outdoor: 12 kVA, 7 isolated outputs (5 × 60 Hz + 2 × 400 Hz), −32 °C … +55 °C, smart PDU included. For a variable 115–220 VAC output adjustable between 60 and 400 Hz from one unit, the PowerGuard 115/200 VAC 400 Hz Static Frequency Converter: 3-phase 360–440 VAC input, star or delta connection. For naval and land platforms that want transformer, converter and distribution in one cabinet, the AC-AC Frequency Converter Transformer System: 12 kVA, 2 × 400 Hz + 5 × 60 Hz outputs, per-output on/off, CAN-Bus. For low-power mission electronics that need 400 Hz and 28 VDC from the same unit, the PowerGuard TPS-115: 3-phase 115 VAC 400 Hz (600 VA) + 3 × isolated 28 VDC (600 W) from a 230 VAC input, 215 × 340 × 123 mm, fanless. If you are looking for a 115/200 VAC 400 Hz power supply, the Static Frequency Converter delivers it in star connection (115 VAC line-to-neutral); in delta it gives 115 VAC line-to-line. The PowerGuard Outdoor's two 4 kVA, 3-phase 115 VAC 400 Hz outputs are delta-connected (line-to-line, no neutral). Selection criteria are in How to select a 115 VAC 400 Hz power supply.

No. The "400" in the name is the input voltage: the PowerGuard 400/115 VAC AC-AC Inverter converts a 3-phase 400 VAC, 50/60 Hz input into a 115 VAC, 50 Hz output and splits a total of 10 kVA across four outputs (3.6 + 2.4 kVA three-phase, 2 + 2 kVA two-phase). The output is delivered through an isolated transformer, so it suits 115 VAC equipment at a site or platform connected to a 400 VAC grid. For equipment that needs 400 Hz, see the static frequency converters above.

Mil-Drive-55 is an FOC (field oriented control) drive for three-phase asynchronous motors: 5.5 kW nominal, 3 × 400 VAC / 0–500 Hz output, 14 A motor current, 400 VAC ±10% input. It supports resolver, incremental and absolute encoder and NTC temperature sensor inputs, and has dual-channel Safe Torque Off (STO), an emergency input and RS-485 and CAN-Bus communication. With a sealed aluminium enclosure and fanless passive cooling it operates from −32 °C to +55 °C, and is designed for applications such as turret drives, antenna positioning, hydraulic pumps and pedestal motion. Alternative power levels, additional I/O channels and custom communication protocols can be configured per project thanks to the modular design.

When the load must see no interruption at all if the mains or shore supply fails, the PowerGuard MIL-UPS-2K3 feeds the load through its inverter at all times with a double-conversion online topology; there is no transfer moment when the battery takes over. It runs from a 115 VAC ±20%, 45–65 Hz, 3-phase input, delivers 115 VAC 60 Hz pure sine at 2.3 kVA and provides 30 minutes of backup at a 2 kW load from a VRLA gel battery. It runs stably on capacitive loads down to a 0.3 power factor, and the manual bypass keeps the load running during maintenance. Radar, communication and console loads on naval and shore systems are the typical use.

Each product has its own interface; choose the one that matches your specification. The PowerGuard Outdoor is monitored from a browser through its built-in web server without additional software and communicates over Ethernet and RS-422 via KN9. The 115/200 VAC 400 Hz Static Frequency Converter uses RS-422 and Ethernet-based desktop software; the 400/115 VAC AC-AC Inverter and the MIL-UPS-2K3 are monitored and switched on and off remotely over Ethernet on the KN6 connector. The AC-AC Frequency Converter Transformer System uses CAN-Bus, the TPS-115 RS-485 HD (10 Mbps), and the Mil-Drive-55 RS-485 and CAN-Bus. Most units also carry an OLED display and/or BIT (built-in test) on the unit itself.

The PowerGuard Outdoor completed MIL-STD-810G CHG-1 environmental (temperature, vibration, shock) and MIL-STD-461E EMI/EMC testing at an ISO/IEC 17025 accredited laboratory, and the PowerGuard 115/200 VAC 400 Hz Static Frequency Converter has passed MIL-STD-810G CHG-1 and MIL-STD-461G testing at an accredited laboratory. The other products are designed to the standards stated in their datasheets: MIL-STD-810G and MIL-STD-461F for the Mil-Drive-55 and MIL-UPS-2K3, MIL-STD-810G and MIL-STD-1399B for the 400/115 VAC AC-AC Inverter, while the AC-AC Frequency Converter Transformer System has been assessed to military test methods. When requesting a report, ask for the standard and method number, the laboratory name, the test date and the serial number of the unit tested. For a quotation, send the input voltage and number of phases, output frequency, total power and number of outputs, indoor or outdoor use and the monitoring interface through the quote form.

All three names describe the same kind of device: a power conversion unit that changes the frequency, and usually the voltage, of an AC supply and rebuilds it at the value the equipment expects, such as 400 Hz or 60 Hz. "Static converter" and "static frequency changer" point to how the conversion is done: with power electronics and no rotating machine. The real distinction is between static and rotary designs: a rotary converter, or motor-generator set, uses a mains-fed motor to turn a generator at the output frequency. The frequency converters in this category are static. In industry, "frequency converter" is also used for variable-speed motor drives; in this category that job belongs to the Mil-Drive-55, which controls motor speed and torque through a variable 0–500 Hz output. Because "converter" on its own can also mean an AC-DC or DC-DC unit, state the input and output frequency in your specification.