摘要:
A drive control signal is effectively obtained. An offset control circuit (32) adds an offset to a rotational state signal. An added signal is obtained by adding an offset to the rotational state signal by repeating a process in which, when it is detected that an added signal in which a predetermined offset amount is added to the rotational state signal on a side approaching a reference value becomes the reference value from one direction at a first time, the offset amount is added to the rotational state signal in a direction returning from the reference value, when it is detected that the obtained added signal becomes the reference value from the one direction at a second time, no value is added to the signal, and, when it is detected that the added signal becomes the reference value at a first time from another direction which is a direction opposite to the one direction and which reaches the reference value, the offset amount is added to the rotational state signal on a side approaching the reference value. A drive control signal is generated in which the level is reduced compared to the sine wave shape signal for a predetermined period of the obtained added signal between the reference value at the second time and a reference value at a next time.
摘要:
A circuit suitable for formation as a small sized IC, able to decrease the number of externally attached parts and reduce the size, and stably rotating a motor. When rotating a rotor 101 by three-phase drive signals U, V, and W generated based on a CLK signal from a VCO 7, induction voltages induced in the three-phase coils 102 are monitored and a phase deviation of a rotor phase relative to an electric phase is detected. As a result, when the rotor phase is late relative to the electric phase, a charge pump circuit 5 is driven by an up signal f_up which becomes active for exactly a time in accordance with the phase delay amount, while when the rotor phase is advanced, the charge pump circuit 5 is driven by a down signal f_down which becomes active for exactly a time corresponding to a phase advance amount. In this motor drive circuit 1, the voltage of a VCO control terminal T_cp is directly and instantaneously and dynamically changed not in accordance with detected phase deviation information without going through a smoothing filter.
摘要:
A control apparatus for an asynchronous machine, in particular as a drive for electric vehicles, is equipped with an incremental transducer for the rotation speed of the asynchronous machine and a torque setpoint transducer, the signals of which can be delivered to a setpoint-value entry device in order to generate setpoint values (three-phase reference sine-wave system) for a closed-loop-controlled inverter or inverter power section to operate the asynchronous machine. The setpoint-value entry device contains means for defining at least the rotor frequency (slip frequency) and the amplitude as a function of the desired torque setpoint value. The setpoint-value entry device contains a summing device for adding or subtracting the rotor frequency to or from the mechanical rotation frequency, corresponding to the rotation speed, of the asynchronous machine as a function of the instantaneous rotation direction, the desired rotation direction, and the direction of the desired torque. On the basis of the output signal of the summing device, current setpoint profiles for the inverter or inverter power section, the amplitudes of which can be set as a function of the predefined amplitude, can be selected from a setpoint memory. This control apparatus allows many advantages of the field-oriented control method, and in particular improved efficiency in part-load operation, to be achieved with little outlay and in economical manner. In the particular case of electric vehicles, smooth starting from rest, or from a rolling motion at any speed opposite to the desired direction of motion, is guaranteed.
摘要:
For achieving an air conditioner being applicable to various a-c source voltages in common and operative with high power factor by suppressing generation of high harmonics, an a-c source voltage from an a-c electric power source 1 is rectified in full-wave by a rectifier 2, and a d-c source voltage Ed of an inverter 13 is obtained by being charged in a condenser 5. Here, there are a-c source voltages of 100 V and 200 V, and a divided voltage Ed1 of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 100 V, a divided voltage Ed2 (here, Ed1>Ed1) of the d-c voltage of the condenser 5 is selected when the a-c source voltage is 200 V, respectively by an exchange switch 18, and is used as a d-c voltage Ed' for controlling on and off of a switch element 6. Though the d-c source voltage Ed differs depending on the a-c source voltage of 100 V or 200 V, it is possible to set the d-c source voltage Ed at a voltage value for operating the inverter 13 with low loss and high efficiency, for each one of the a-c source voltages, by setting a ratio of the voltage division appropriately.
摘要:
A motor drive system for selectively supplying a drive current to a multiple phase motor having each phase winding divided into a plurality of discrete windings includes a plurality of H-bridge drives to control the polarity and magnitude of the drive current. Each H-bridge drive include a pair of half bridge drives interconnected to the terminals of each of the discrete windings. Each of the half bridges have an upper bridge switching element and a lower bridge switching element for coupling the positive and negative potential, respectively, of a DC power source to each discrete winding. The discrete windings of each phase winding are coupled in series by a plurality relays which are selectively actuated by a controller to interconnect the discrete windings in predetermined groups dependent upon the shaft speed of the motor. The controller also controls the excitation of the bridge switching elements whereby the bridge switching elements disposed at the end terminals of each group of discrete windings are actuated and the other bridge switching elements are turned off to provide the desired current to the phase windings of the motor.
摘要:
The invention relates to a method for detecting a threshold-crossing of a back electromotive force (bemf) measured in one phase of a multiple-phase motor, the one phase being set at a high impedance while at least one other phase is supplied by pulse-width modulation signal. The method includes the step of comparing the bemf with a threshold. The method includes, prior to the step of comparing, the steps of sampling the bemf during on-periods of the pulse-width modulation signal, and holding the bemf during off-periods of the pulse-width modulation signal.
摘要:
Electric motors having controllable induced armature fields, such as induction motors and synchronous reluctance motors, are used in power assisted steering systems for motor vehicles. Power is conserved by tailoring induced armature fields or rotor flux in accordance with the speeds of motor vehicles including the power assisted steering system. In particular, one or more flux programs or maps are provided for the power assisted steering system with the flux map or program being accessed or addressed by means of the vehicle speed. During low speed operation of the motor vehicle, for example to perform parking maneuvers where speeds are near zero and steering forces are near or at maximum, the rotor flux is programmed to maximum. For high speed operation, such as highway and rural motor vehicle operation, the rotor flux is programmed to a low value so that internal loss mechanisms in the power assist motor and motor controller are minimized yet provide sufficient rotor flux to meet steering needs such as lane changes, obstacle avoidance and the like. Various transition speeds and flux transition curves provide smooth transitions between high flux levels and low flux levels.
摘要:
A control unit for a motor and a control method for it, which are adapted for conducting control at a high speed so that efficiency of the motor by inverter operation of an induction motor is maximum at all times. This unit comprises means (3) for detecting effective power delivered to a motor (14), calculation means (1, 2, 4, 5, 6, 7, 8 16, S.sub.1, S.sub.2, S.sub.3) for calculating, from the detected effective power and frequency (f) of an A.C. voltage delivered to motor (14), supply voltage (V.sub.1) to motor (14) where efficiency of motor (14) becomes maximum, and means (9, 10, 11, 12) for delivering the calculated supply voltage (V.sub.1) to motor (14).
摘要:
A current regulation process and device for a three-phase, static-converter-fed, permanently excited synchronous machine with a trapezoidal magnet wheel voltage. A phase angle sensor is mounted on the motor shaft of the machine and is coupled to an evaluating device providing an actual speed of rotation value. Current measurement devices measure the currents to the machine. A current actual value spatial vector is generated from two phase current actual values, which spatial vector is estimated as a function of a calculated normalized magnet wheel voltage, whose rotor flux-oriented current components are supplied to current regulators, which generate a voltage spatial vector. A simple field-oriented current regulation is achieved for a three-phase, static-converter-fed, permanently excited synchronous machine with a smooth torque at low rotation speeds and low intermediary circuit or battery current ripple at high rotation speeds.
摘要:
Polarity change of a feed-forward compensation signal for compensating for a dead-time voltage disturbance is synchronized with zero crossings of a load current reference. The load current reference is advanced in time by adding a fixed phase angle, scaled by the synchronous frequency, to the synchronous coordinates angle. The load current reference is time-advanced only for timing the polarity change of the feed-forward compensation signal and not for application to the current regulators; the current regulators still use the load current reference (unadvanced). For a converter, the load current would be an AC mains input current. For an inverter, the load current could, for example, be an induction motor stator current. The shape of the feed-forward compensation signal is approximately trapezoidal and is obtained from the limited, amplified, advanced load current reference. The shape of the feed-forward compensation signal is a function of at least one of: the load current frequency, the load current amplitude and an amplification scaler.