a household appliance

Abstract

The invention discloses a household appliance, comprising: a motor, which collects the bus current through a sampling resistor set on the bus of a three-phase inverter circuit, and controls the motor by adopting a vector control method according to the bus current; a PFC circuit; a current and voltage control loop, which uses For controlling the PFC circuit; the processing unit is configured to output a variable for compensating the target value of the bus voltage according to the PWM signal output by the vector control method and the minimum sampling time Tmin, so that the difference ΔT between Ts and Tmin is greater than zero ; Ts is the sampling time of the sampling resistor. The invention adjusts the pulse signal width applied to the motor coil by compensating the target value of the bus voltage of the PFC circuit, realizes correct sampling of the bus current, and reliably controls the motor, thereby realizing reliable control of household appliances.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a household appliance. Background technique [0002] Permanent magnet synchronous motors are mostly used in household appliances (such as air conditioners, refrigerators, washing machines, etc.), and the mainstream control algorithm for permanent magnet synchronous motors is Field-Oriented Control (FOC), also known as vector control. FOC controls the current of the motor, therefore, the acquisition of the U / V / W three-phase coil phase current of the motor is necessary. [0003] Detecting the phase current of the motor by sampling the DC bus current is the so-called single-resistor sampling technique. figure 1 This is the schematic diagram of the structure of this technology. The sampling resistor R1 is connected in series between the connection point X of the three lower bridge arms and the negative terminal of the DC power supply, and the instantaneous value of the bus cur...

AI Technical Summary

Problems solved by technology

[0005] If the boost voltage of the PFC boost circuit is higher and the bus voltage is higher, in order to keep the effective voltage applied to the motor winding constant when the motor current remains constant, the pulse width will be narrowed and the sampling window will be smaller, which may lead to premature Enter the situation of Ts<Tmin and cannot sample accurately

[0006] Therefore, in order to avoid the problem of insufficient single-resistor sampling window caused by the high DC bus voltage, this application proposes a method to improve the actual sampling pulse width by adjusting the bus voltage boost target value of the PFC circuit to meet the single-resistor sampling requirements , to achieve reliable control of household appliances

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