New energy vehicle drive motor phase loss detection method

Abstract

The invention discloses a new energy vehicle drive motor phase loss detection method. The method is based on the motor control principle. When the inverter controls the motor to run, the sum of its three-phase currents is zero. When any one phase is out of phase, the other two The phases form a loop, and when any two or three phases are missing, the loop cannot be formed; during static detection, a fixed angle is selected according to the rotor position, and a specific current vector that makes the motor not work is given, and the three-phase current is recorded. According to the rotor position and The corresponding relationship of the current judges whether there is a phase loss in the motor. After the static detection, the vehicle is dynamically detected. At this time, the real-time three-phase current value is collected, and the effective value of the phase current is calculated. According to the relationship between the three-phase effective values, the motor is judged. Whether there is a phase loss, if there is a phase loss, it will report a fault and control the vehicle to run with reduced power. The method adapts to the operating conditions of new energy vehicles, improves detection accuracy, avoids false alarms of phase loss faults, avoids missed detections, and ensures reliable operation of motors and controllers.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a method for detecting lack of phase of a driving motor of a new energy vehicle. Background technique [0002] New energy vehicles have been vigorously promoted due to their high efficiency, energy saving and environmental protection, and have become the development trend of the automobile industry. At the same time, the safety issues of new energy vehicles have gradually attracted widespread attention from the whole society. [0003] The motor and inverter are the core of the new energy vehicle power system. Once a problem occurs, the vehicle will not be able to drive, and it may cause personal injury in severe cases. Usually, the motor and the inverter are connected by a three-phase power line. After long-term use, the joints may become loose and broken due to vibration and corrosion. At the same time, because the motor and inverter need to inject a large current during n...

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Problems solved by technology

[0013] The above methods have high detection accuracy under specific working conditions. However, for new energy vehicles, which have high performance requirements and complex working conditions, it is easy to cause misjudgment or missed detection. For method a, when the battery voltage Instability, or when the torque fluctuation is large, the bus voltage will fluctuate greatly, which will affect the reliability and accuracy of detection; for method b, the three-phase imbalance is related to the control system, component accuracy, motor consistency, and operating conditions. etc. are related, so it is more difficult to use the basis for phase loss detection; for method c, it is generally considered that the motor is in normal operation, a phase current is less than a certain threshold, and a phase loss phenomenon occurs. For single-phase phase loss It has high judgment accuracy, but when there is a two-phase phase loss, the three-phase current is relatively small due to the detection error at this time, which is similar to the current when the vehicle is running at a low speed and a constant speed, unless the system has extremely high detection accuracy, otherwise method c cannot be directly applied to new energy vehicle drive motor phase loss fault detection

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