摘要:
A switched reluctance drive, operating either as a motor or a generator, is controlled in a stable manner in the continuous current mode in the presence of supply voltage or electrical load variation. The use of a current control parameter I x in addition to the conventional on- and off-angles θ on , θ off gives the ability to operate smoothly in the continuous current mode and to transition smoothly between operating modes. Once the phase current reaches a pre-determined level I x , the phase winding may be placed in a freewheel state, thereby controlling the standing current in the phase winding and/or the output voltage.
摘要:
A simple rotor position transducer for an electronically commutated electric motor has a vane mounted to rotate with the rotor and a pair of sensors. One sensor has an output coincident with positions of zero torque. The other sensor produces signals slightly in advance. Overlapping portions of the signals denote regions of different levels of torque. The second sensor output can also be used in high-speed, single-pulse control of the motor.
摘要:
An electrical drive system includes an electrical machine controlled by an electronic controller, which requires feedback of signals representing quantities associated with the operation of the electrical machine. These signals may represent, for example, flux, current and/or rotor position. The integrity of these signals is validated by setting suitable thresholds for the signals and confirming that both are present at the appropriate time.
摘要:
A switched reluctance drive, operating either as a motor or a generator, is controlled in a stable manner in the continuous current mode in the presence of supply voltage or electrical load variation. The use of a current control parameter I x in addition to the conventional on- and off-angles θ on , θ off gives the ability to operate smoothly in the continuous current mode and to transition smoothly between operating modes. Once the phase current reaches a pre-determined level I x , the phase winding may be placed in a freewheel state, thereby controlling the standing current in the phase winding and/or the output voltage.
摘要:
A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimised and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold.
摘要:
A switched reluctance drive is controlled without using a physical rotor position detector. The control method estimates the standing flux-linkage associated with the phase and uses this estimate to improve its subsequent estimate of rotor position. The method works robustly regardless of whether the current is continuous or discontinuous.
摘要:
A polyphase switched reluctance machine is controlled by a control system using sensorless position detection. The controller is robust and reliable and operates over the entire current chopping range of the machine. Diagnostic pulses of predetermined flux-linkage are injected into a phase, whether or not it has residual current flowing.
摘要:
An electrical drive system includes an electrical machine controlled by an electronic controller, which requires feedback of signals representing quantities associated with the operation of the electrical machine. These signals may represent, for example, flux, current and/or rotor position. The integrity of these signals is validated by setting suitable thresholds for the signals and confirming that both are present at the appropriate time.
摘要:
A brushless electrical machine has at least one phase winding which produces magnetic flux in the machine. A controller controls the flux in the machine with reference to a demanded flux and a stabilisation signal which, in combination, enable the controller to operate in a stable manner in the presence of disturbances in the inputs or parameters of the controller. The controller is able to operate with either a hardware rotor position detector or with a sensorless position algorithm.