A control method and system for a resonant linear compressor applied for controlling the capacity of a cooling system. The method includes: a) reading a reference operation power (P.sub.ref) of the motor of the compressor; b) measuring an operation current (i.sub.MED); c) measuring an operation voltage of a control module of the compressor; d) calculating an input power (P.sub.MED) of the motor as a function of the operation current (i.sub.MED) and of the operation voltage; e) comparing the input power (P.sub.MED) with the reference operation power (P.sub.ref); f) if the reference operation power (P.sub.ref) is higher than the input power (P.sub.MED), then increase an operation voltage of the compressor (UC); g) if the reference operation power (P.sub.ref) is lower than the input power (P.sub.MED), then decrease the operation voltage of the compressor (UC).

The invention relates to a Direct Current (DC) air conditioning compressor drive unit for use in both buildings and in vehicle installations. Energy savings can be demonstrated in the automotive industry when compared to the current status of known DC air conditioning drive units and in particular those relying on direct or pulley drive. More particularly, when coupled to DC battery and inverter technology for air conditioning purposes within domestic housing, commercial and industrial buildings, it can provide extreme energy savings. Preferably, the purpose of this innovation is to enhance the viability and energy savings opportunities of using DC power in air conditioning if used in conjunction with smart compressor technology.

A pump device including a first piezoelectric pump, a second piezoelectric pump connected in series with the first piezoelectric pump on a downstream side of the first piezoelectric pump, a drive unit configured to supply AC power as input power to each of the first piezoelectric pump and the second piezoelectric pump, a control unit configured to control input power to the first piezoelectric pump and the second piezoelectric pump, and a power supply unit configured to supply power to the drive unit, in which the control unit sets input power of the second piezoelectric pump to be larger than input power of the first piezoelectric pump.

A linear compressor or method of operation may provide for driving a motor of the linear compressor to a reference current and detecting a sampled current during driving the motor. The linear compressor or method may also provide for calculating a variance in current using the sampled current, determining the calculated variance exceeds a variance threshold, and restricting the reference current based on determining the calculated variance exceeds the variance threshold.

An oscillating positive displacement pump with at least one mobile part arranged to be movable relative to a fixed part. The mobile part is driven and drives a displacement element of the positive displacement pump. An electrodynamic drive is provided as a drive, on which a plurality of coils and permanent magnets are provided that are arranged on the mobile part of the drive respectively, and at least one guide member is provided on the drive, which allows the mobile part to move only along a degree of translation freedom. The positive displacement pump is designed as a diaphragm pump, which is associated with a measurement and control unit with a data storage and data processor, which processes a position signal of the mobile part and the strength of the drive current as a measured and/or control variable. An arrangement of a plurality of such positive displacement pumps and a method of operating at least one such oscillating positive displacement pump are also provided.

Provided is a linear motor control apparatus capable of improving estimation accuracy of a resonance frequency immediately after start, and a compressor equipped with the linear motor control apparatus. A linear motor control apparatus includes a winding to which an AC voltage is applied and a mover which is connected to an elastic body, in which the linear motor control apparatus includes an operation mode (1) which monotonously increases amplitude of the AC voltage while keeping a frequency of the AC voltage substantially constant, and an operation mode (2) which changes the frequency of the AC voltage while keeping the amplitude of the AC voltage substantially constant, and executes the operation mode (1) and the operation mode (2) in this order.

A linear compressor according to the present disclosure may include a piston reciprocating within a cylinder, a motor providing a driving force for the motion of the piston, a sensing unit configured to sense a motor voltage and a motor current associated with the motor, a discharge portion provided at one end of the cylinder to regulate the discharge of refrigerant compressed in the cylinder, a control unit configured to compute at least one control parameter associated with the motion of the piston using at least one of the motor voltage and the motor current sensed by the sensing unit, and a deep learning operation unit configured to receive the control parameter, and output a compensation value associated with an absolute position of the piston using artificial neural network technology.

An actuation system for a resonant linear compressor (50), applied to cooling systems, the latter being particularly designed to operate at the electromechanical frequency of said compressor (50), so that the system will be capable of raising the maximum power supplied by the linear actuator, in conditions of overload of said cooling system. Additionally, an actuation method for a resonant linear compressor (50) is disclosed, the operation steps of which enable one to actuate the equipment at the electromechanical resonance frequency, as well as to control the actuation thereof in over load conditions.

Method for controlling a linear pump (9) of a vapour recovery system in a fuel dispensing unit (1). The linear pump (9) is flow controlled by a signal. The method comprises applying (SI) a known voltage to a solenoid coil (10) of the linear pump (9) for a predetermined time period, measuring (S2) a current consumption of the solenoid coil (10) during the predetermined time period, and adjusting (S3) the signal based on the measured current consumption. The invention also relates to a vapour recovery system for recovering vapour from a motor vehicle tank via a fuel dispensing nozzle (7) to a vapour tank.

The invention relates to a method for controlling a linear pump of a vapour recovery system in a fuel dispensing unit. The linear pump is flow controlled by a signal. The method comprises applying a known voltage to a solenoid coil of the linear pump for a predetermined time period, measuring a current consumption of the solenoid coil during the predetermined time period, and adjusting the signal based on the measured current consumption. The invention also relates to a vapour recovery system for recovering vapour from a motor vehicle tank via a fuel dispensing nozzle to a vapour tank.