Permanent magnet synchronous motor permanent magnet linkage online measurement system and method

Abstract

The present invention relates to a permanent magnet synchronous motor permanent magnet linkage online measurement system. The system comprises a vehicle control unit, a motor control unit, an inverter and a permanent magnet synchronous motor. The method comprises the following steps: performing initialization of the system electrifying; reading the temperature of the motor stator; checking the table according to the read temperature of the motor stator to obtain the initial linkage of the permanent magnet; determining an active short circuit instruction; determining whether the rotation speed of the motor exceeds an inflection point rotation speed [Omega]g or not; enforcing the active short circuit; detecting any two-phase current and rotor position, and calculating the phase current amplitude and the motor rotation speed; and checking the table of the permanent magnet linkage, and obtaining the relation curve between the phase current amplitudes and the rotation speeds of different permanent magnet linkage values with the permanent magnet linkage. The permanent magnet synchronous motor permanent magnet linkage online measurement system and method are able to measure independent of motor body parameters such as the resistance of the stator, the rectangular axis inductance, the rectangular axis voltage and the like and with no need for extra hardware circuit and software algorithm, only need enforcement of active circuit control, are compatible to the control of the permanent magnet synchronous motor, and are simple and reliable.

Description

technical field [0001] The invention belongs to the technical field of motor drive control, and in particular relates to an online measurement system and a measurement method for permanent magnet flux linkage of a permanent magnet synchronous motor. Background technique [0002] New energy vehicles are driven by multiple power sources, among which, the power sources include motors and engines. In general, the motor can be driven simultaneously with the engine or independently to complete various vehicle working modes. Permanent magnet synchronous motors have become the mainstream of automotive motors due to their high efficiency, high power density and high torque density. The working environment temperature of most permanent magnet synchronous motors for vehicles is between -40°C and 150°C. In this temperature range, the characteristics of permanent magnets can change by more than 20%. As the temperature increases, the magnetic properties gradually decrease, and exceeding...

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Problems solved by technology

This method is limited by the accuracy of AC phase voltage measurement. It is difficult for general voltage sensors to meet the requirements, and a high-precision voltage sensor is required. In addition, this sensor must have good environmental adaptability (such as operating temperature from -40 ℃ to 125℃), so it will increase the hardware cost

[0008] In summary, since the online identification method of the permanent magnet flux depends on the L of the permanent magnet synchronous motor body d , L q and R s As well as parameters that are difficult to measure such as the conduction voltage drop and dead time of the inverter, and the use of wireless telemetry technology will inevitably introduce a large number of sensors, resulting in increased costs and complicated space layout. Therefore, a simple and reliable On-line identification system and method for permanent magnet flux linkage of permanent magnet synchronous motor is imperative

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