Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a driver section may be provided in a free-piston combustion engine for storing energy during an expansion stroke. The driver section may be configured to store sufficient energy to perform the subsequent stroke. In some embodiments, the driver section may be configured to store sufficient energy so as to enable the engine to operate continuously across engine cycles without electrical energy input. A linear electromagnetic machine may be provided in a free-piston combustion engine for converting the kinetic energy of a piston assembly into electrical energy.

A load adaptive linear electrical generator system is provided for generating DC electrical power. The electrical generation system includes one or more power generation modules which will be selectively turned on or off and additively contribute power depending on the DC power demand. Each power generating module includes a pair of linear electrical generators connected to respective ones of a pair of internal combustion piston based power assemblies. The piston in the internal combustion assembly is connected to a magnet in the linear electrical generator. The piston/magnet assembly oscillates in a simple harmonic motion at a frequency dependent on a power load of the electrical generator. A stroke limiter constrains the piston/magnet assembly motion to preset limits.

Systems and methods are provided for braking a translator of a linear multiphase electromagnetic machine. The system detects a fault event, and in response to detecting the fault event, causes the translator to brake using an electromagnetic technique. Braking includes causing the translator to stop reciprocating, by applying a force opposing an axial motion, which may occur within one cycle, or over many cycles. The fault event may include, for example, a fault associated with an encoder, a controller, an electrical component, a communications link, a phase, or a subsystem. The system includes a power electronics system configured to apply current to the phases. The system may use position information, current information, operating parameters, or a combination thereof to brake. Alternatively, the system need not use position information, current information, and operating parameters, and may brake the translator independent of such information.

Systems and methods for providing power to devices at a well site employ a linear alternator to generate power at a well site. The linear alternator is mounted on a pump at the well site and uses the up-and-down motion of the pump to generate power. The pump may be a nodding donkey head pump or other sucker rod pump mechanisms that operate based on linear vertical motion. The linear vertical motion drives a linear rotor back and forth through a linear stator to induce current in the linear alternator. This allows the linear alternator to convert a portion of the mechanical work performed by the pump into electrical energy that can be supplied to the devices. In some embodiments, the pump-mounted linear alternator can be equipped with a position sensor to directly measure a vertical position of the pump as the alternator travels up and down with the pump.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a driver section may be provided in a free-piston combustion engine for storing energy during an expansion stroke. The driver section may be configured to store sufficient energy to perform the subsequent stroke. In some embodiments, the driver section may be configured to store sufficient energy so as to enable the engine to operate continuously across engine cycles without electrical energy input. A linear electromagnetic machine may be provided in a free-piston combustion engine for converting the kinetic energy of a piston assembly into electrical energy.

Systems and methods are provided for braking a translator of a linear multiphase electromagnetic machine. The system detects a fault event, and in response to detecting the fault event, causes the translator to brake using an electromagnetic technique. Braking includes causing the translator to stop reciprocating, by applying a force opposing an axial motion, which may occur within one cycle, or over many cycles. The fault event may include, for example, a fault associated with an encoder, a controller, an electrical component, a communications link, a phase, or a subsystem. The system includes a power electronics system configured to apply current to the phases. The system may use position information, current information, operating parameters, or a combination thereof to brake. Alternatively, the system need not use position information, current information, and operating parameters, and may brake the translator independent of such information.

An engine includes an engine block with at least one cylinder bank including cylinder bores formed therein. A piston is reciprocatingly disposed in each of the cylinder bores. A crankshaft is rotatably mounted to the engine block. Connecting rods are rotatably attached to the crankshaft and are coupled to the piston. A cylinder head with intake valves and exhaust valves in fluid communication with the cylinder bores is mounted to each cylinder bank. At least one permanent magnet is disposed in a skirt of each piston. At least one electromagnet is positioned adjacent to the permanent magnet(s). A control system selectively provides an electrical current to the electromagnets to produce a desired magnetic field, wherein the magnetic field of the electromagnets cooperates with a magnetic field of the permanent magnets to affect a motion of the piston in respect of the engine block.

A free piston generator based on a rigid synchronous transmission system is provided, which belongs to the technical field of power energy. The present disclosure solves the problems of low power generation efficiency and low stability of the existing free piston generator. The free piston generator based on the rigid synchronous transmission system includes a first linear generator set, a second linear generator set, a rigid synchronous transmission assembly, two high-pressure cylinders arranged at two ends of the first linear generator set, and two low-pressure cylinders arranged at two ends of the second linear generator set. The combustion product is firstly subjected to first-stage expansion in the high-pressure cylinder and is then subjected to second-stage expansion in the low-pressure cylinder, which effectively increases the energy utilization in exhaust gas, also increases the expansion work, and further improves the thermal efficiency and the power generation efficiency of the free piston generator. By means of the rigid synchronous transmission assembly, high-pressure pistons and low-pressure pistons are always kept in stable phase operation, so as to avoid the problems of wall-impingement and insufficient pressure of compressed air due to the phase mismatching.

A load adaptive linear electrical generator system is provided for generating DC electrical power. The electrical generation system includes one or more power generation modules which will be selectively turned on or off and additively contribute power depending on the DC power demand. Each power generating module includes a pair of linear electrical generators connected to respective ones of a pair of internal combustion piston based power assemblies. The piston in the internal combustion assembly is connected to a magnet in the linear electrical generator. The piston/magnet assembly oscillates in a simple harmonic motion at a frequency dependent on a power load of the electrical generator. A stroke limiter constrains the piston/magnet assembly motion to preset limits.

Systems and methods are provided for braking a translator of a linear multiphase electromagnetic machine. The system detects a fault event. A polarity indicative of an electromotive force in determined in at least one phase of the linear multiphase electromagnetic machine caused by a motion of the translator. In response to detecting the fault event, the system causes, based on the polarity, a current to be applied to a respective phase of the at least one phase to cause a force acting on the translator that opposes an axial motion of the translator to cause the translator to brake. Braking includes causing the translator to reciprocate at a reduced velocity by opposing axial motion over one or more cycles. The system may use one or more of position information, current information, operating parameters, to brake, or may brake the translator independent of such information.