Abstract:
A surge voltage generated by the switching operation of an IGBT element and voltage variation generated in an equivalent series resistance of a capacitor are superimposed on an input voltage of an inverter. The equivalent series resistance has a temperature dependence that a resistance value increases with a decrease in a capacitor temperature. The IGBT element has a temperature dependence that an element withstand voltage decreases with a decrease in an inverter temperature. When capacitor temperature is lower than a predetermined threshold value, a control device reduces an upper limit value of the input voltage by an amount corresponding to the voltage variation from its upper limit value at a high temperature, and controls a target voltage of a boost converter such that an output voltage does not exceed the upper limit value. Consequently, the allowable range of the surge voltage can be ensured.
Abstract:
A controller for a vehicle including at least one motor driving wheels, an inverter driving the motor, and a boosting converter supplying a dc power supply current to the inverter, is provided with a control portion performing rectangular wave control and non-rectangular wave control on the inverter in a switched manner. The control portion has an emergency switching condition for switching control from the rectangular wave control to the non-rectangular wave control, as a determination reference, and when the emergency switching condition is satisfied while the rectangular wave control is being executed (YES at step S5), the control portion instructs the boosting converter to lower target output voltage (S7). Preferably, the control portion determines that the emergency switching condition is satisfied when a q-axis current supplied from the inverter to the motor exceeds a prescribed threshold value.
Abstract:
An upper limit value setting unit of a control device conducts integration on the change in battery power, and determines whether the integrated value is lower than a preset first threshold value (negative value). When determination is made that the integrated value is lower than the first threshold value, and the battery power difference is lower than the second threshold value (negative value), the upper limit value setting unit sets Vup2 that is lower than the general Vup1 as the upper limit value of the inverter input voltage command.
Abstract:
A wind turbine control system for twin turbines mounted in common on an accelerator comprising a DC boost converter having pulse width capability, power, speed, current and voltage sensors responsive to an generator driven by one turbine, and a controller. The controller adjusts the PWM duty cycle to adjust generator output whereby to control turbine thrust and thereby adhere to a desired performance curve, and also changes thrust to adjust angular position of the accelerator and thus maintain optimum angle of attack of the wind on turbine blades.
Abstract:
In a motor drive control system configured to include a converter capable of stepping up the voltage, when the locked state of MG2 operating as an electric motor does not occur (NO in S130), a voltage command value VHref for the converter output voltage is set according to respective required voltages of MG1 operating as an electric generator and MG2 (S140). In contrast, when the locked state of MG2 occurs (YES in S130), the voltage command value VHref is set to a limit voltage Vlmt or less for limiting the voltage step-up by the converter (S150, S180). When the locked state occurs, the converter output voltage is decreased and accordingly the DC voltage switched by the inverter is lowered, so that a switching loss at the switching device forming a part of the inverter is reduced and the temperature increase due to the heat generation can be suppressed.
Abstract:
In one technique of the present invention, DC electric power from a DC bus is inverted to provide AC electricity to one or more electrical loads, and AC power from a variable speed generator is rectified to provide a first variable amount of electric power to the DC bus. This technique also includes determining power applied to the electrical loads, and dynamically controlling the amount of power supplied from the generator and an electrical energy storage device in response to the power applied to the loads.
Abstract:
Method of controlling a movable member driven by an electric motor by monitoring current circulating through the electric current and ripples therein. The method including detecting current peaks and count the number of current peaks falling within sampling windows such that the number of current peaks falling within the sampling windows are used to determine an angular position of the electric motor for use in facilitating the control thereof.
Abstract:
A system and method of starting or restarting an engine on a locomotive having at least one of another engine, a fuel cell system and an energy storage system. The method is applicable to large systems such as trucks, ships, cranes and locomotives utilizing diesel engines, gas turbine engines, other types of internal combustion engines, fuel cells or combinations of these that require substantial power and low emissions utilizing multiple power plant combinations. The method is directed, in part, at a flexible control strategy for a multi-engine systems based on a common DC bus electrical architecture so that prime power sources need not be synchronized.
Abstract:
A voltage command value of a converter is set by executing the step of determining a candidate voltage of a system voltage VH as a converter output voltage in a voltage range from the minimum necessary voltage corresponding to induction voltage of a motor generator and a maximum output voltage of the converter; the step of estimating power loss at the battery, converter, inverter and motor generator, at each candidate voltage, and calculating total sum of estimated power loss of the overall system; and the step of setting the voltage command value VH# based on the candidate voltage that minimizes the total sum of estimated power losses among the candidate voltages.
Abstract:
A power converter for a switched reluctance motor or a permanent magnet brushless direct current (dc) motor may include first and second partial circuits for forming multiple conduction circuits in cooperation with first and second phase windings of the motor. The controller also includes a switch operable to open and close a first conduction circuit, which includes the first phase winding, and to regulate energization of the first and second phase windings of the motor through opening and closing the first conduction circuit. Control of the switch provides four-quadrant operation of the motor through regulated energization of the first and second phase windings.