Patent Publication Number: US-2018037135-A1

Title: Method of Controlling Speed of Electric Vehicle in Keeping with Controller Temperature

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to controlling speed of an electric vehicle; more particularly, relates to controlling the speed in keeping with temperature of a controller for achieving good safety on operating the electric vehicle and prolonging use-life of the electric vehicle. 
     DESCRIPTION OF THE RELATED ART 
     A common controller for an electric vehicle will generate heat on operating. If the heat is not dissipated immediately, the controller may not be operated as normal, and may be even burnt. Therefore, the electric vehicle must monitor temperature of the controller in a real time for achieving security on driving and further prolonging use-life of the electric vehicle. 
     However, the electric vehicle is mostly not set up with a device to detect the temperature of the controller. Therefore, on operating the electric vehicle, security is bad and use-life of the electric vehicle becomes short. 
     Hence, the prior art does not fulfill all users&#39; requests on actual use. 
     SUMMARY OF THE INVENTION 
     The main purpose of the present invention is to control speed of an electric vehicle in keeping with temperature of a controller for achieving good safety on operating the electric vehicle and prolonging use-life of the electric vehicle. 
     To achieve the above purposes, the present invention is a method of controlling speed of an electric vehicle in keeping with controller temperature, where the electric vehicle has an actuating device; the actuating device comprises a controller, a motor, at least two wheels and a power unit; the motor is connected to the controller; the wheels are connected to the motor; the power unit is connected to the controller; and the method comprises steps of: (a) during operating the electric vehicle, continuously detecting temperature of the controller generated; (b) comparing the temperature with a preset temperature for determining whether temperature of the controller is too high; and, (c) when the temperature of the controller is determined to be too high, reducing a current provided to the motor to lower down speed of the electric vehicle and further reduce the temperature of the controller. Accordingly, a novel method of controlling speed of an electric vehicle in keeping with controller temperature is obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which 
         FIG. 1  is the flow view showing the preferred embodiment according to the present invention; and 
         FIG. 2  is the view showing the interactions between the function blocks in the preferred embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description of the preferred embodiment is provided to understand the features and the structures of the present invention. 
     Please refer to  FIG. 1  and  FIG. 2 , which are a flow view showing a preferred embodiment according to the present invention; and a view showing interactions between function blocks in the preferred embodiment. As shown in the figures, the present invention is a method of controlling speed of an electric vehicle in keeping with controller temperature. The electric vehicle has an actuating device. The actuating device comprises a controller  21 , a motor  22 , at least two wheels  23  and a power unit  24 . The motor  22  is connected to the controller  21 . The wheels  23  are connected to the motor  22 . The power unit  24  is connected to the controller  21 . The method according to the present invention comprises the following steps: 
     (a) Temperature detection  11 : During operating the electric vehicle, temperature of the controller  21  generated is continuously detected by a temperature-detecting unit  25 . 
     (b) Comparison  12 : The temperature is transferred to a processing unit  26 . The processing unit  26  receives the temperature from the temperature-detecting unit  25  to compare the temperature with a preset temperature stored in the processing unit  26  and determine whether the temperature of the controller  21  is too high. Therein, the preset temperature is 57 celsius degrees (° C.)˜65° C. while 59° C. is preferred. 
     (c) Speed control  13 : When the temperature of the controller  21  is too high, the processing unit  26  drives a speed adjustment unit  27  to cut down a current supplied by the power unit  24  to the motor  22 . When the temperature of the controller  21  detected in step (b) is 55° C.˜72° C., the speed adjustment unit  27  is driven by the processing unit  26  to adjust the current provided by the power unit  24  to the motor  22  to limit a highest speed of the electric vehicle to 45 kilometers (km). When the temperature of the controller  21  detected in step (b) is 65° C.˜82° C., the speed adjustment unit  27  is driven by the processing unit  26  to adjust the current provided by the power unit  24  to the motor  22  to limit the highest speed of the electric vehicle to 33 km. When the temperature of the controller  21  detected in step (b) is higher than 82° C., the speed adjustment unit  27  is driven by the processing unit  26  to adjust the current provided by the power unit  24  to the motor  22  to limit the highest speed of the electric vehicle to 8 km. After the temperature of the controller  21  detected is lowered down, the highest speed of the electric vehicle is restored to the related preset value. Thus, by reducing speed when the temperature of the controller  21  is too high, good safety is achieved and use-life of the electric vehicle is prolonged. 
     To sum up, the present invention is a method of controlling speed of an electric vehicle in keeping with controller temperature, where good safety is achieved on operating an electric vehicle and use-life of the electric vehicle is prolonged. 
     The preferred embodiment herein disclosed is not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.