摘要:
A system for controlling power from an AC voltage to an induction motor to reduce surge when power is restored to a power grid is disclosed including, a device for switching power to the induction motor that has a trigger controllable to enable the device to provide a variable amount of power to the induction motor. The system includes a second device for measuring the AC voltage at the source to determine when power is available, hence determining when the AC voltage is within operating range. Responsive to the AC voltage coming within operating range, the system delays for a time period then initiates power to the induction motor by controlling the device for switching power.
摘要:
In order to realize, without inviting cost increase, a control for maintaining a pressure of fluid delivered from a pump at a target value, a pump control unit is provided with a driver control unit controlling a rotational speed of a hydraulic pump through adjustment of a duty ratio of a PWM signal driving excitation coils of an electric motor. Further, the pump control unit is provided also with a signal correction circuit configured to convert a current flowing in the excitation coils to a voltage signal with using a shunt resistor and to divide the voltage signal with using a voltage division ratio setting circuit and to shorten an ON signal of the PWM signal by increasing the divided voltage. The voltage division ratio setting circuit has a characteristics of setting the divided voltage higher, the longer an ON period of the PWM signal.
摘要:
The present invention relates to a method, a system and an electronic device (15), especially designed for start and control of the functioning of a single-phase induction motor (12). Said motor (12) comprises a run winding (10) and a start winding (11), the start winding (11) is electrically associated to an electronic start device (15), the run winding (10) and the electronic start device (15) are electrically associated to an alternating voltage source (F) configured to supply feed energy to the motor (12), the start winding (11) is kept de-energized at a first operation instant (Top1) of the motor (12). More particularly, the present invention is configured to energize the start winding (11) through the electronic start device (15) in the condition in which a first voltage signal (Vsamp1), sampled from the alternating voltage source (F), through a sensor element (7), is lower than or equal to a first voltage reference (V1), or higher than or equal to a second voltage reference (V2), so as to initiate a start period of the motor (12).
摘要:
A control system for a single-phase induction motor including at least: one electronic control, a main switch, an auxiliary switch, one voltage conditioner block, the main switch being electrically associated to the main winding and the auxiliary switch to the auxiliary winding, the control circuit being electrically associated to the voltage conditioner block and to the switches, the switches being turned on or off by the control circuit, the control system and the motor being electrically associable to an alternating voltage source, the conditioner block is associated in parallel to the auxiliary switch, the conditioner block being capable of accumulating energy when the auxiliary switch is turned off, the conditioner block being arranged to supply electrical power greater than a minimum value to the control circuit, for at least a start-up time, by way of the energy accumulated in the conditioner block, when the switches are turned on.
摘要:
A system for controlling power from an AC voltage to an induction motor to reduce surge when power is restored to a power grid is disclosed including, a device for switching power to the induction motor that has a trigger controllable to enable the device to provide a variable amount of power to the induction motor. The system includes a second device for measuring the AC voltage at the source to determine when power is available, hence determining when the AC voltage is within operating range. Responsive to the AC voltage coming within operating range, the system delays for a time period then initiates power to the induction motor by controlling the device for switching power.
摘要:
A polyphase electric motor has a rotor, a stator with a plurality of slots, a plurality of main windings and a plurality of auxiliary windings installed in slots of the stator, and a main winding and an auxiliary winding that correspond to a selected phase of an alternating current power source. The auxiliary windings are connected to the motor terminals through a plurality of capacitors, and the auxiliary windings and corresponding capacitors are connected in parallel to the main windings. The main winding and the auxiliary winding of the selected phase are offset by about 60 to about 120 electrical degrees. A power of the plurality of main windings is at least 75% of a power of the polyphase electric motor at full load rating and the power of the plurality of main windings is motoring at 25% of the full load rating.
摘要:
An energy saver delay circuit for an induction motor is disclosed. The energy saver delay circuit includes a power factor control circuit including an integrator, the integrator having a negative summing junction and a current injection circuit electrically connected to the negative summing junction, the current injection circuit configured for injecting an offset current into the negative summing junction to cause about the maximum available voltage from a power source to be supplied to the motor for a predetermined amount of time. Current injection may be triggered by voltage being applied to the motor, wherein the voltage exceeds a predetermined value. Alternatively, current injection may be triggered by current flowing through the motor, responsive to the current exceeding a predetermined threshold current. Alternatively, current injection may be triggered by voltage across the power factor control circuit, responsive to the voltage exceeding a predetermined threshold voltage.
摘要:
A method and device for starting single-phase asynchronous motors which substantially consists in disengaging the start winding of a single-phase asynchronous motor, after its starting, by using a switching means that is connected in series to the start winding. The switching means is controlled as a function of a starting time and of a starting voltage.
摘要:
A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.
摘要:
Method and device for operating an asynchronous motor having increased efficiency. According to the invention, ranges for a motor size of the asynchronous motor are specified. In addition, a value of the motor size is calculated depending on at least one measurement value of a measurement parameter during the operation of the asynchronous motor, wherein the respective calculated value of the motor size is allocated to one of the ranges. Furthermore, a control parameter is changed depending on the range to which the calculated motor parameter is allocated to provide an optimised control parameter such that the control parameter is changed beginning from a starting value specified for the respective range of the motor size until a predetermined criterion for a specific motor size is reached. Furthermore, the optimised control parameter is stored as a support point of a continuous optimal characteristic curve for the control parameter depending on the range to which the calculated motor size is allocated.The asynchronous motor can thus be more effectively operated by actuation by means of the provided continuous optimal characteristic curve.The invention also relates to a block wiring diagram for a corresponding device, to process diagrams for corresponding methods and to a computer program product for carrying out said method.