Starting method of permanent-magnet synchronous compressor for variable-frequency air conditioner

Abstract

The invention discloses a starting method of a permanent-magnet synchronous compressor for a variable-frequency air conditioner, which comprises the following steps of: firstly locking the initial position of a rotor through a PARK process, then carrying out open-loop starting, switching to a closed-loop control mode for trial operation when the dragging frequency of a permanent-magnet synchronous motor reaches the lowest frequency Ft of switching an open loop to a closed loop when in open-loop starting, reading a magnetic flux valve to judge whether the closed-loop control mode is successfully switched for operation or not, and if the closed-loop control mode is not successfully switched, adjusting the PARK current and the frequency acceleration of the open-loop starting process for restarting according to the magnitude of the magnetic flux valve; and setting the limitation of starting times, reporting a fault signal to an upper computer after unsuccessful starting for many times, and giving a restarting signal by the upper computer. The invention can guarantee the reliable starting of the permanent-magnet synchronous compressor under the condition of heavier or lighter loads.

Description

technical field [0001] The invention relates to the field of frequency conversion air conditioners, in particular to a method for starting a permanent magnet synchronous compressor used in frequency conversion air conditioners. Background technique [0002] With the continuous development of air-conditioning technology, inverter air conditioners have gradually entered thousands of households. At the same time, people not only have higher and higher requirements for the reliability and comfort of inverter air conditioners, but also increase the energy consumption of inverter air conditioners. The more attention is paid, the energy consumption of the AC inverter compressor used in the prior art inverter air conditioner can no longer meet the user's requirements. It not only consumes a lot of iron and copper during operation, but also has a certain speed slip during operation. Optimal torque control cannot be achieved, and more useless work is done, resulting in waste of electr...

AI Technical Summary

Problems solved by technology

However, since the position of the rotor cannot be estimated when it is stationary, the start-up of the permanent magnet synchronous compressor has become a difficult problem. At present, most manufacturers use a current with a certain frequency and amplitude to make the permanent magnet synchronous compressor run in an open loop. stage, after the permanent magnet synchronous motor rotor is dragged to a certain frequency, then switch to the closed-loop stage according to the feedback rotor information

However, since the load of the motor of the permanent magnet synchronous compressor is uncertain and the sudden change is large, the above startup method is likely to cause the permanent magnet synchronous compressor to fail to start, especially when the load is heavy or light.

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