8results about How to "Reduce the absolute value" patented technology

The utility model relates to the technical field of power electronics, and discloses an overcurrent protection circuit and a power supply circuit, the overcurrent protection circuit comprises a voltage sampling circuit, a current sampling circuit, a voltage threshold determination circuit and a current threshold determination circuit, the second input end inputs reference voltage, and the output end is connected with the first input end of the current threshold judgment circuit; the second input end of the current threshold judgment circuit inputs the output current of the to-be-protected equipment, and the output end of the current threshold judgment circuit is connected with the control end of the to-be-protected equipment; when the voltage threshold judgment circuit judges that the bus voltage is smaller than or larger than the reference voltage, the absolute value of an overcurrent protection point in the current threshold judgment circuit is a first current value or a second current value, and the first current value is larger than the second current value. According to the utility model, when the bus voltage is higher than a threshold value, an over-current protection point is lowered, so that the device stress and turn-off loss of equipment to be protected are reduced.

The present application provides a method, device, vehicle and storage medium for controlling mode switching, the method comprising: in the process of switching the vehicle from the series mode to the direct drive mode, when it is determined that the second clutch is open, controlling the second input shaft to be engaged in an even gear; if it is detected that the gear position of the second input shaft is neutral, determining that the even gear on the second input shaft is unavailable; when it is determined that the even gear on the second input shaft is unavailable, if it is monitored that the vehicle meets the preset conditions for switching to the series mode, controlling the second clutch to close; when the second clutch is in a closed state, controlling the first clutch to open, so that the vehicle switches back from the direct drive mode to the series mode. The method can automatically switch back to the series mode when the vehicle is stuck during the mode change process, ensuring the normal power output of the vehicle.

The utility model relates to a cooling structure of a segmented stator core and a flat wire motor, the cooling structure comprises a stator core, the stator core comprises at least two segments including a first iron core segment and a second iron core segment, a gap is left between the first iron core segment and the second iron core segment, and the first iron core segment and the second iron core segment are arranged in parallel. The stator slots on the first iron core section and the second iron core section are open slots and are formed by enclosing two adjacent stator teeth, two sides of one end, close to the rotor, of each stator tooth are respectively provided with a convex block, and each convex block is provided with a notch and shoulder oil duct hole. According to the utility model, the absolute value of AC copper loss is reduced; meanwhile, a groove shoulder area is secondarily utilized, an oil duct hole is designed, the temperature of a groove opening conductor is further reduced from the heat dissipation angle due to the fact that a cooling medium is close to a heating source, the oil duct is close to an air gap and is also close to a permanent magnet on the rotor side, the heat transfer path is short, a good cooling effect on the permanent magnet is achieved, and the high-temperature demagnetization risk of the permanent magnet is greatly reduced.

The application discloses a neodymium-iron-boron permanent magnet and a preparation method thereof. The neodymium-iron-boron permanent magnet is in the shape of a cuboid, the height direction of the neodymium-iron-boron permanent magnet is the orientation direction, and the height of the neodymium-iron-boron permanent magnet is greater than or equal to 8 mm. The content of heavy rare earth elements at the top corner of the neodymium-iron-boron permanent magnet is greater than 0.65 wt%, the content of heavy rare earth elements at the edge of the neodymium-iron-boron permanent magnet is greater than 0.43 wt%, the content of heavy rare earth elements at the outer layer of the neodymium-iron-boron permanent magnet is greater than or equal to 0.22 wt%, and the content of heavy rare earth elements at the core of the neodymium-iron-boron permanent magnet is greater than or equal to 0.003 wt%. The content of heavy rare earth elements at the top corner is greater than that at the edge, the content of heavy rare earth elements at the edge is greater than that at the outer layer, and the content of heavy rare earth elements at the outer layer is greater than that at the core. The neodymium-iron-boron permanent magnet has a large size in the orientation direction and good heat demagnetization resistance.

The invention discloses a permanent magnet synchronous motor predictive current control method and system, and belongs to the technical field of permanent magnet synchronous motor control. When a torque instruction changes drastically in a medium-high speed range, output voltage saturation is extremely easy to occur in dead-beat predictive current control, so that q-axis current is difficult to excite to an instruction value by the saturated output voltage in a sampling period, and the dynamic performance of torque rise at the medium-high speed is seriously reduced. Therefore, under the condition, the rising speed of the q-axis current is increased through flux weakening operation, and then the operation of increasing the torque is carried out at the higher q-axis current rising speed. The optimal flux-weakening current is determined based on a q-axis current rise time prediction algorithm, so that the total time required by flux-weakening operation and torque rise operation is minimum, and the torque dynamic performance of dead-beat prediction current control under medium and high speeds can be effectively improved.

Disclosed is a display device including: a display panel including a plurality of pixels configured to receive an initialization voltage through an initialization voltage line; a controller configured to output a voltage control signal for controlling a voltage level of the initialization voltage; and a power manager configured to provide the initialization voltage to the initialization voltage line, the power manager changes the voltage level of the initialization voltage to an initialization level at or after a power-on time at which power is started to be supplied and before a display-on time at which an image is started to be displayed, based on the voltage control signal, and the power manager changes the voltage level of the initialization voltage to a target level corresponding to the brightness of the image at or after the display on time based on the voltage control signal.

The present application relates to a liquid crystal alignment agent which satisfies at least one selected from the group consisting of (I) and (II). (I): contains a polymer (A) having a repeating unit selected from the group consisting of a repeating unit represented by the following formula (1-a) and a repeating unit represented by the following formula (1-i), and an epoxy compound (B) represented by the following formula (2). (II): contains a reaction product of the polymer (A) and the epoxy compound (B).

The invention relates to a method and a controller for operating a motor vehicle designed as a fuel cell vehicle. The motor vehicle has a high-voltage system, an electric machine, a high-voltage energy store and a fuel cell system, the method having the following steps: When the high-voltage energy store is operated with an operating power which is greater in absolute terms than a continuous power and smaller in absolute terms than a maximum permissible peak power, a period of time is detected in which the high-voltage energy store is operated with the electrical power. When the detected period of time reaches a maximum permissible period of time, the maximum permissible peak power of the high-voltage energy store is reduced by a time gradient in absolute terms to the continuous power. When the difference between the maximum permissible peak power and the operating power reaches a threshold value, the electrical operating power of the fuel cell system is increased in a traction mode and reduced in a coasting mode, wherein the electrical operating power of the high-voltage energy store is reduced in absolute terms to less than the continuous power in order to provide the electrical power requirement of the motor vehicle in total.