A power unit based on the technology of a Free Piston Stirling Engine (FPSE) is applied in our sources of stand-alone power supply.

The Stirling engine is a thermodynamic system with external heat supply, designed to convert thermal energy into mechanical energy of reciprocating motion.

The FPSE construction consists of two main moving parts: the displacer and the working piston. Both work in a closed helium environment and are not mechanically connected to each other.

Mechanical energy is generated through two temperature zones in the engine in which helium is heated and cooled. Due to the temperature difference and cyclical movements of the displacer, a pressure wave is created that moves the pistons.

Structurally, the engine is a combination of several heat exchangers in a single unit: a heater, a regenerator and a cooler, forming an internal circuit.

The external case of the engine forms a hermetic space filled with an inert gas - helium - under the pressure of 3.6 Mpa.

The piston and displacer move freely in the cold and hot zones of the internal circuit of the engine without any lubrication. Compaction in the gap is achieved by means of gas-dynamic pressurization in the gap and the creation of a gas cushion.

To convert the mechanical energy of the reciprocating motion of the working piston into electrical energy, a single-phase synchronous linear generator is used, the inductor of which is connected to the working piston with permanent magnets. The generator creates a sinusoidal voltage, the magnitude of which is proportional to the amplitude of the piston oscillation, and the frequency is determined by the speed of movement of the piston and is 50 +/- 0.5 Hz.

During the reciprocating motion of the inductor, the magnetic flux of the permanent magnets induces a variable sinusoidal emf with a nominal value of 230 V in the stator winding. To reduce losses from eddy currents induced by alternating magnetic flux in the hollow cup of the inductor, axial slots are made around the periphery of the cup. It also allows to reduce the mass of the movable part of the generator.

Key benefits of our product:

  1. Long service life - from 50,000 to 100,000 hours
  2. High electrical efficiency - up to 25%
  3. Low fuel consumption
  4. High efficiency in cogeneration modes
  5. No maintenance is required for the entire service life
  6. Multi-fuel capacity
  7. There is no limit on the number of start and stop cycles
  8. Exceptional reliability
  9. Wide load control range
  10. Low noise and vibration
  11. No lubrication system is required