Dynamometer-based method for measuring and analyzing efficiency of electric motor of electric bicycle

Abstract

The invention relates to a dynamometer-based method for measuring and analyzing the efficiency of the electric motor of an electric bicycle. The method comprises the following steps: a, a measuring device is connected with the electric bicycle; b, the output voltage of a DC stabilized power supply equals to the rated voltage of the electric motor, a rolling handle is adjusted, and the maximum open state is maintained; c, after the output voltage of the DC stabilized power supply reaches 1.25 times the rated voltage, the corresponding output voltage is gradually reduced until the undervoltage protection starts, and a measurement result is recorded; d, a power loss curve graph is drawn; the output voltage of the DC stabilized power supply equals to the rated voltage of the electric motor until the electric motor reaches the rated output power; e, the DC resistance of the electric motor is measured to obtain copper loss; f, the power loss of the controller of the electric motor is obtained according to the input power, the output power, electric copper loss, electromechanical loss, armature iron loss and stray losses of the electric motor; g, and the efficiency of the electric motor is obtained. The method is simple, economical and practical, and has the advantages of high measuring accuracy and good applicability.

Description

technical field [0001] The invention relates to a method for measuring and analyzing the efficiency of an electric bicycle motor based on a dynamometer, specifically a method for measuring and analyzing the efficiency of an electric bicycle motor considering the influence of the motor controller on the efficiency of the motor, which belongs to the measurement of electric bicycles technical field. Background technique [0002] Due to the advancement of control technology and sensor technology, the application of permanent magnet materials and Hall materials has increased, and the application of permanent magnet DC brushless motors in electric bicycles has become increasingly popular, and gradually occupies a dominant position in domestic electric bicycle products. The permanent magnet DC brushless motor and the motor controller are two important components inside the electric bicycle, and the performance of the two components has a great influence on the performance of the el...

AI Technical Summary

Problems solved by technology

But in fact, the power loss measurement schemes of the above two motor controllers are difficult to implement. On the one hand, because the power loss of the controller is not large, if the power measurement instrument is used for measurement, the measurement instrument must have high measurement accuracy ( Such as Japan's YOKOGAWAWT3000), but the cost of such equipment is generally high, so the purchase of such equipment may lead to an increase in the investment cost and production cost of the company's measuring equipment; on the other hand, due to the structure and manufacturing of controllers from different manufacturers The process is different, if the circuit analysis method is used to measure the power loss of the controller, it will inevitably consume a lot of time, thereby reducing the measurement speed, so the method of measuring the efficiency of the electric bicycle motor through circuit analysis is difficult to achieve, especially the controller of the same manufacturer There may also be differences in the types of components (such as power tubes) used in the circuit breaker, which also brings difficulties to the implementation of the circuit measurement method.

It can be seen that the power loss of the motor controller is difficult to implement in actual measurement operations

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