Plaset, S.p.a.

United Technologies Motor Systems, Inc.

Brea Impianti S.u.r.l.

Askoll P&c S.r.l.

Emerson Appliance Motors Europe S.r.l.

Motors Acquisition Corp.

Encosys S.r.l.

Sebastiano Acquaviva

Nicolino Alvaro

Piergiorgio Ricco

Domenico Diacono

A control system for a hydraulic elevator. The system () controls an elevator () which includes an elevator cylinder () with a piston () coupled to a car (), a pump () having an outlet coupled to the elevator cylinder (), and an electric motor () coupled to the pump (). A speed regulator () for controlling the speed of the car () is driven in predetermined modes, such that the pump () rotates at predefined speed. The speed regulator () is driven such that the motor () of the pump () is supplied with a voltage having a frequency (f) the value of which corresponds to a predefined speed value (&#x3c9;), increased by an amount (cf; f, f) which is a predetermined function of the working pressure (P) of the pump (). This balances the effect of the leakage of operating hydraulic fluid in the pump ().

Control system for a hydraulic elevator, which includes a speed regulator for controlling the speed of displacement of the elevator car

A control system is provided and includes energy accumulators () coupled to a first inverter () and controlled through a second inverter (). These accumulators () are adapted to store the energy generated by an electrical machine () associated with the elevator apparatus (), and the energy coming by a source and optionally not used by the machine (), as well as to deliver the stored energy towards the machine () when this requires energy with a power higher than a threshold. The system is arranged to automatically cause the lifting of the car () up to the highest floor when preset conditions occur in a time interval of inactivity of the elevator apparatus ().

Control system and energy storage for an elevator apparatus

A control system for a motor, including a first detector providing signals indicative of the sign and zero-crossings of a supply voltage, and a second detector providing signals indicative of the sign and the zero-crossings of BEMF developed in the stator winding. A switch is driven to cause a first current pulse through the winding at a first delay relative to the zero-crossing of the supply voltage. The system checks if the BEMF has a first zero-crossing within a predetermined period of time preceding a third zero-crossing of the voltage, and if so, causes an opposite second current pulse through the winding with a second delay relative to the third zero-crossing of the supply. If not, the first current pulse is repeated, reducing or increasing the duration of the first delay if the first zero-crossing of the BEMF took place after or before the predetermined period of time.

Control system without position sensors for a synchronous electric motor

The control system comprises a switch (TR) in series with a stator winding (W) between two terminals (A, B) connected to an alternating supply voltage source (V), a first detector circuit () capable of providing a signal (V) indicating when the current (I) in that winding (W) is zero, a second detector circuit () capable of providing a signal (V) indicating the magnitude of the supply voltage (V), and a control unit (MC) connected to the first and second detection circuits () and designed to control the switch (TR) in such a way as to cause an alternating current (I) of the same frequency as the supply voltage (V) and having alternating positive and negative phases (11, 12) to pass through the winding (W), separated by intervals during which it remains at zero, of a duration (t) which varies according to an increasing function of the magnitude of the supply voltage (V).

System for controlling the steady-state rotation of a synchronous electric motor

The system (ECS) comprises a rectifier circuit (RC) to supply a direct current voltage (VB) as output; a driver circuit (DC) which is connected to a rectifier circuit (RC) and includes a plurality of controlled switches (SW-SW) which can permit passage of a current in the stator winding (W) selectively in one direction and in the opposite direction; a sensor (PS) which can supply a signal (H) which is indicative of the angular position of the rotor (R); and a control circuit (CC) which is designed to receive a signal (RS) which is indicative of the speed of rotation required (&#x3c9;ref) for the motor (M), and is connected to the position sensor (PS). The control circuit is designed to generate, from the passage of the rotor (R) to a predetermined position, a counting signal (N) which is a function of the time (t), and to reset this signal (N) when it reaches a predetermined value (Nref) corresponding to the speed of rotation required (&#x3c9;ref) for the motor (M); and then to control the driver circuit (DC) selectively on the basis of the position signal (H) of the rotor or on the basis of the counting signal (N), when the speed of rotation (&#x394;) of the motor (M) is respectively lesser and greater than the speed required (&#x394;ref).

System and method for controlling a synchronous electric motor, particularly for household appliances

The drive circuit () includes a processing and control circuit () comprising a protection circuit (), designed to generate at its output a logical inhibiting signal (C) starting from every zero crossing of the motor supply volts (V), the inhibiting signal (C) having a predetermined duration (t) which is less than a quarter of the period of the supply voltage (V); and an enabling circuit (), connected to a sensor of the position of the rotor () and designed to enable a first and a second controlled conduction device () associated with the stator winding () to conduct current alternately, in synchronization with the signal (H) supplied by the position sensor (). The enabling circuit () is connected to the protection circuit () in such a way that the conduction of current through the controlled conduction device () enabled at any time is inhibited for the duration (t) of the inhibiting (C).

Drive circuit for a synchronous electric motor

The driver circuit (,) comprises a first triac or the like (,) for connection in series with the stator winding (,) of the motor between the terminals (,) of an alternating-current voltage supply, the gate of the first triac (,) being arranged for connection to an intermediate point (C) of the stator winding (,) of the motor (M). A second triac or the like (,) is connected between the intermediate point (C) of the winding (,) and the terminal (,) of the voltage supply to which the first triac (,) is connected. A control circuit (,) is connected to the gate of the second triac (,) such that, each time the motor (M) is connected to the voltage supply, it initially makes the second triac (,) conductive and consequently cuts off the first triac (,) for a predetermined initial period of time. and cuts off the second triac (,) and allows the first triac (,) to become conductive after this period of time.

Electric motor and driver system

The system comprises sensors (PS) for detecting the angular position of the rotor (R) of the motor and a driver circuit (DC) arranged to control conduction in the controlled switches (SW) associated with the phases (W) of the motor and in a regulation switch (RSW) in predetermined manner in dependence on the position signals emitted by the sensors (PS). The regulation switch (RSW) is driven in an on/off manner by means of a square-wave signal. The system further comprises a protection circuit (PC) with a capacitor (C) connected to the control input of the regulation switch (RSW) so that the capacitor (C) is charged each time the regulation switch (RSW) is made conductive by the square-wave signal in operation, and with a control switch (T) connected between the control input of the regulation switch (RSW) and a pole (GND) of the direct-current supply and having a control input connected to the capacitor (C). The control switch (T) is made conductive and cuts off the regulation switch (RSW) when the latter remains conductive continuously for a period of time longer than a predetermined period.

Electric motor and motor control system

The motor comprises a rotor with permanent magnets with at least one pair of poles, a stator having a winding wound around a magnetic circuit, position-detectors for providing driving signals in dependence on the angular position of the rotor, and a driver circuit for controlling the flow of current in the stator winding in dependence on the signals supplied by the position-detectors. The winding is divided into a first half-winding and a second half-winding wound around the magnetic circuit in opposite directions. The driver circuit comprises first and second controlled switches in series with the first stator half-winding and with the second stator half-winding, respectively, in respective circuit branches arranged in parallel between the supply terminals. These switches have respective control inputs connected to the position-detectors in an arrangement such that, during steady-state operation, respective unidirectional currents having a frequency equal to half of the frequency of the alternating supply voltage flow through the half-windings alternately.

Synchronous electric motor

A brushless electric motor has a rotor carrying a plurality of permanent magnet elements uniformly spaced apart and a stator armature separated from the rotor by a circumferential air gap of uniform thickness and having a plurality of uniform slots provided therein at equally spaced intervals and facing the air gap. The cogging torque associated with the motor is reduced by bevelling the inner corners of the magnet elements and spacing the magnet elements apart at a desired spacing so as to provide a desired distribution for the density of magnetic energy stored in the air gap. Magnetic flux conductors may also be disposed on the magnet elements to affect the distribution of the density of the magnetic energy stored in the air gap.

Permanent magnet electric motor having reduced cogging torque

The driver circuit (10) comprises a first triac or the like (11) for connection in series with the stator winding (5, 6) of the motor between the terminals (12, 13) of an alternating-current voltage supply, the gate of the first triac (11) being arranged for connection to an intermediate point (C) of the stator winding (5, 6) of the motor (M). A second triac or the like (15) is connected between the intermediate point (C) of the winding (5, 6) and the terminal (13) of the voltage supply to which the first triac (11) is connected. A control circuit (15-27) is connected to the gate of the second triac (15) such that, each time the motor (M) is connected to the voltage supply, it initially makes the second triac (15) conductive and consequently cuts off the first triac (11) for a predetermined initial period of time, and cuts off the second triac (15) and allows the first triac (11) to become conductive after this period of time.

Driver circuit for a synchronous, alternating current electric motor

System for controlling a brushless electric motor

A method and system is provided for controlling the operation of a brushless electric motor of the type having at least two phase windings, each of the phase windings being connected in series with a respective switch to form a respective circuit branch between the terminals of a constant voltage source thereby forming a plurality of said circuit branches in parallel to each other. A plurality of signals, each signal indicative of the electromotive force developed in a respective one of the phase windings during operation of the motor, is generated and compared with a predetermined reference value so as to generate synchronization logic signal. A control signal indicative of the angular rotor position of the motor is generated using the synchronization signal and compared with a first and a second reference signal for generating respective processing signals for controlling the current flow in each said respective circuit branch. The reference signals may be varied so as to modify the time of initiating the flow of current and ceasing the flow of current in the respective phases.

Method and system for controlling a brushless electric motor for optimal

A continuous current brushless electric motor is disclosed in which the phases (W1, W2, W3) are energized sequentially, so that a time interval exists in which one phase being deactivated and another phase being activated are both energized with current. During this time interval, the current supplied to the phase being deactivated is decreasing while the current supplied to the phase being activated is increasing. The rate of decrease in the current in the phase being deactivated is controlled to be equal approximately to the difference between a predetermined reference current (Iref) and the increasing current in the phase being activated.

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Pino Torinese, Italy

Sebastiano Acquaviva