Power stacks
PM-1844-3.3-1
Power stacks
| Type of converting: | Inverter (DC-AC) |
| Rated power: | - |
| Input voltage Uinput [V]: | 5500 |
| Output voltage Uout [V]: | 3300 |
| Input current Iinput [A]: | - |
| Output current Iout [A]: | 1844 |
| Power semiconductors: | IGBT |
| Type of cooling: | Liquid cooling |
- Documents and certificates
- Description
The FM‑1844‑3.3‑1‑V‑OM4 inverter is a three‑level DC‑AC power inverter unit built on Press‑Pack IGBT transistors and Press‑Pack FRD diodes in tablet‑type packages. The unit is designed to convert 5 500 V DC into adjustable 3 300 V AC at an output current of 1 844 A, delivering a maximum single‑phase inverter output power of up to 5 MW.
The unit implements a T‑NPC topology (Transistor Neutral Point Clamped — a three‑level inverter with transistor‑clamped neutral point). Unlike the classic NPC scheme, where clamping diodes are used to connect the midpoint, in T‑NPC this function is performed by transistors.
Key features:
- Fewer series‑commutated switches at the same number of output voltage levels — reduces switching losses;
- Improved output voltage waveform — the three‑level signal is closer to a sine wave and contains fewer higher harmonics, reducing the requirements for output filters;
- Lower dv/dt of output voltage — reduces stress on motor winding insulation and cable runs, which is particularly important for high‑voltage marine electric motors;
- Use of lower‑voltage IGBT switches at high DC bus voltage — achieved by distributing the voltage across series‑connected elements.
Press‑Pack technology. The use of Press‑Pack IGBT transistors and FRD diodes in tablet‑type packages with double‑sided liquid cooling of in‑house manufacture ensures:
- High power density — 11 kW/L — thanks to double‑sided heat dissipation from the semiconductor die and the absence of solder joints inside the package;
- Operation in aggressive environments — the hermetic metal‑ceramic package design permits use in explosive and chemically aggressive environments typical of marine and industrial applications;
- High thermal cycling capability — the absence of wire bonds inside the package eliminates metal fatigue under cyclic heating and cooling, which is critical for frequent load variation modes (vessel manoeuvring, pump start‑stop cycles);
- Safe failure behaviour — under critical overload, a Press‑Pack device enters a stable short‑circuit state rather than rupturing, allowing the inverter to continue operating with the damaged cell disconnected.
All power units manufactured by Proton‑Electrotex JSC can be additionally equipped on request: snubber circuits for protection against switching overvoltages, resistive dividers, current, voltage, and temperature sensors, and various types of drivers.
Power assemblies are developed to meet individual customer requirements — simply fill out the dedicated questionnaire to specify your parameters.
- Applications
The power unit is designed for use in high‑voltage three‑level frequency converters with T‑NPC topology, which convert DC voltage into adjustable AC voltage for powering high‑power electric motors.
Operating principle. In a high‑voltage frequency converter, the power unit functions as an inverter — it converts the DC bus voltage into a three‑level AC voltage with adjustable frequency and amplitude.
The three‑level output voltage waveform ensures a near‑sinusoidal motor current waveform, reduces torque ripple, and minimizes stress on winding insulation — which is critical for high‑voltage motors rated at 3.3 kV and above. The maximum output power of a single inverter phase reaches 5 MW, enabling the construction of frequency converters ranging from a few to tens of megawatts.
Typical applications:
- Frequency converters for icebreaker propulsion motors — nuclear and diesel‑electric icebreakers with power from 20 to 120 MW;
- Frequency converters for azimuth thrusters (Azipods) of high ice‑class vessels — LNG carriers, tankers, bulk carriers, container ships, supply vessels;
- Frequency converters for Azipods on dynamically positioned (DP) offshore platforms — drilling platforms, support vessels;
- Frequency converters for oil and gas pipeline pumping units — trunk oil and gas pipelines;
- Frequency converters for metal‑rolling mills — stand drives, winders, and shears;
- Frequency converters for main circulation pumps (MCP) of nuclear power plants — reactor cooling circuit drives.
Press‑Pack IGBT‑based power units are used where power conversion from a few to tens of megawatts is required at high voltage (3.3 kV and above), with stringent requirements for reliability, maintainability, and the ability to operate in harsh climatic conditions — including marine and Arctic installations.
