Operation of household appliance having BLDC drive motor

Abstract

The invention relates to a method (S0-S6) for operating a domestic appliance (1), in which, in order to start a BLDC drive motor (5) of the domestic appliance (1), an actual rotational speed (omega) of a rotor (7) of the BLDC drive motor (5) is set up from its rest state by means of a deterministic setting torque (Mref, det), and an actual angle (theta) and the actual rotational speed (omega) of the rotor (7) are determined by means of high-frequency injection; when the actual rotational speed (omega) reaches or exceeds the first switching rotational speed, the actual rotational speed (omega) is adjusted to the set rotational speed (omega ref), and when the actual rotational speed (omega) reaches or exceeds the second switching rotational speed, the actual angle (theta) and the actual rotational speed (omega) are determined from the EMK signal. The invention also relates to a household appliance (1) having a BLDC drive motor (5), the household appliance (2) being designed to carry out the method (S0-S6). The invention can be advantageously applied in particular to the start-up of a BLDC drive motor which drives a reciprocating piston compressor of a refrigeration circuit of a domestic refrigeration appliance, in particular of a refrigerator.

Description

Technical Field

[0001] The invention relates to a method for operating a household appliance, in which, for starting a BLDC drive motor of the household appliance, the actual rotational speed of the rotor of the BLDC drive motor is increased from its standstill, and the actual angle and the actual rotational speed are determined by means of high-frequency injection. The invention also relates to a household appliance with a BLDC drive motor, wherein the household appliance is configured to carry out the method. The invention can be used in particular to advantage for starting a BLDC drive motor which drives a reciprocating piston compressor of a refrigeration circuit of a household refrigeration appliance, in particular a refrigerator. Background Art

[0002] DE 10 2020 203 488 A1 discloses a household appliance and a method for operating a household appliance. The household appliance comprises a component and a regulated electric drive, the electric drive having a permanent-magnet three-phase synchronous motor, in particular a converter for controlling an adjustment element of the three-phase synchronous motor and a field-oriented regulator for controlling the adjustment element. The three-phase synchronous motor comprises a stator and a rotor rotatably supported relative to the stator and is part of the component or is configured to drive the component, the method comprising the following method steps: during an operating phase of the electric drive, the regulated electric drive is operated in a speed-regulated manner by means of a field-oriented regulation and according to an angular position of the rotor relative to the stator determined by means of longitudinal and transverse currents of the three-phase synchronous motor and a mathematical model, and during a braking phase after the operating phase of the electric drive, the regulated electric drive is operated in a speed-regulated manner by means of a field-oriented regulation and according to an angular position of the rotor relative to the stator determined by means of longitudinal and transverse currents of the three-phase synchronous motor and a mathematical model. The invention relates to a method for reducing the rotational speed of a three-phase synchronous motor by operating the motor until the rotational speed reaches a predetermined limiting speed, - superimposing a supply voltage generated by an adjusting element and provided for operating the three-phase synchronous motor with a high-frequency voltage, whereby the line current and the longitudinal and transverse currents of the three-phase synchronous motor have corresponding high-frequency current components, - determining the high-frequency current components of the longitudinal and transverse currents, - determining the angular position of the rotor relative to the stator based on the high-frequency current components of the longitudinal and transverse currents, and - further reducing the rotational speed of the three-phase synchronous motor by speed-controlled operation of a regulated electric drive by means of field-oriented regulation and based on the angular position of the rotor relative to the stator determined by means of the high-frequency current components of the longitudinal and transverse currents.

[0003] DE 10 2020 203 489 A1 discloses a household appliance and a method for operating a household appliance. The household appliance comprises a component and a regulated electric drive, the electric drive having a permanent-magnet three-phase synchronous motor, in particular an adjusting element configured as an inverter for controlling the three-phase synchronous motor, and a field-oriented regulator for controlling the adjusting element. The three-phase synchronous motor comprises a stator and a rotor rotatably supported relative to the stator and is part of the component or is configured to drive the component, the method comprising the following method steps: during the starting phase of the electric drive, - a supply voltage generated by the adjusting element and configured to operate the three-phase synchronous motor is superimposed with a high-frequency voltage, whereby the line current of the three-phase synchronous motor has a corresponding high-frequency current component, - a longitudinal and transverse current associated with the three-phase synchronous motor, formed by the line current having a high-frequency current component corresponding to the high-frequency voltage, - a current is determined based on the high-frequency current components of the longitudinal and transverse currents. the angular position of the rotor relative to the stator, and - increasing the speed of the three-phase synchronous motor by means of field-oriented regulation and speed-regulated operation of the regulated electric drive as a function of the angular position of the rotor relative to the stator determined by means of the high-frequency current components of the longitudinal and transverse currents, until the three-phase synchronous motor reaches a predetermined limiting speed, and during an operating phase following the starting phase, speed-regulated operation of the regulated electric drive by means of field-oriented regulation and as a function of the angular position of the rotor relative to the stator determined by means of the longitudinal and transverse currents of the three-phase synchronous motor and a mathematical model.

[0004] For example, it is known from DE 10 2016 210 443 A1 or DE 10 2017 213 069 A1 to superimpose a high-frequency voltage on the supply voltage of a three-phase synchronous motor, which high-frequency voltage results in a corresponding, superimposed high-frequency component of the line current of the three-phase motor in order to determine the angular position of the rotor of the three-phase AC motor relative to the stator. Summary of the invention

[0005] The object of the present invention is to at least partially overcome the disadvantages of the prior art and in particular to provide the possibility of starting or starting the BLDC drive motor of a reciprocating piston compressor of a household appliance more gently and quietly for the mechanical parts of the household appliance, in particular to reduce the disturbing noise of knocking (the so-called "Knocking Noise").

[0006] This object is achieved according to the features of the independent claims. Preferred embodiments can be gathered in particular from the dependent claims.

[0007] This object is achieved by a method for operating a domestic appliance, in particular for starting a BLDC drive motor of a domestic appliance, in which method:

[0008] - increasing the actual rotational speed ω of the rotor of the BLDC drive motor from its rest state in a controlled manner by means of a deterministic set torque, and determining the actual (position) angle θ and the actual rotational speed ω of the rotor by means of high frequency injection HFI,

[0009] - If the actual speed ω reaches or exceeds the predetermined first switching speed, the actual speed ω is adjusted to the set speed ω ref ,and

[0010] If the actual rotational speed ω reaches or exceeds a predefined second switching speed, the actual angle θ and the actual rotational speed ω are determined with the aid of the EMK.

[0011] This method has the following advantages: Since the position angle or the angular position is known exactly when the HFI method is used and the actual speed ω is low, an effective use of the adjustment torque is achieved, because the torque can be adjusted safely. As a result, the BLDC drive motor can be started more gently for the mechanical parts of the household appliance. In this way, the probability of the occurrence of interference noise (knocking noise) is also kept low. It is used here that the HFI method can determine the actual angle θ and the actual speed ω with sufficient accuracy starting from a speed ω of zero.

[0012] Switching from the HFI method to the EMK method at higher actual speeds results in the following advantages: The disadvantages of determining the actual angle and the actual speed by means of high-frequency injection at higher actual speeds are avoided. Thus, at higher actual speeds, it may happen, for example, that the computing power is insufficient to calculate the actual angle and the actual speed in a short time.

[0013] The household appliance may be a refrigeration appliance such as a refrigerator, a freezer or a combination thereof. The household appliance may be a laundry processing appliance such as a washing machine, a laundry dryer or a combination thereof (washing and drying machine). However, the household appliance may also be a dishwasher, for example.

[0014] A “BLDC drive motor” is understood to be a brushless direct current motor that is provided (ie, arranged and configured) for driving further components of a domestic appliance. In particular, the rotor of the BLDC drive motor can serve as a drive shaft.

[0015] The start-up may also be referred to as starting or beginning. One configuration is that, in the stationary state of the BLDC drive motor, the actual rotation speed ω of the BLDC drive motor is zero, that is, the BLDC drive motor starts from this state.

[0016] A "deterministic" set actuating torque is in particular a set actuating torque which is not generated by regulation but is calculated from measured data or stored data and / or read out from a data memory, for example with the aid of at least one characteristic curve or with the aid of table values. The deterministic set actuating torque can be parameterized, ie it is output as a function of at least one parameter.

[0017] The controlled increase of the actual speed by means of a deterministic setpoint actuating torque comprises in particular providing the deterministic setpoint actuating torque as an input variable or a predefined parameter of a controller. This may in particular be a torque controller.

[0018] In the case of high-frequency injection, a high-frequency voltage is superimposed on the supply voltage of the BLDC drive motor, which leads to a corresponding, superimposed high-frequency component of the line current or motor current of the BLDC drive motor in order to determine the actual angle of the rotor of the BLDC drive motor relative to the stator. The actual angle can also be called the actual position angle or the actual angular position. The actual rotational speed of the rotor can be determined from the actual angle.

[0019] The actual speed is controlled to the setpoint speed, in particular, by outputting the setpoint actuating torque as a manipulated variable of the speed controller. That is, when a first speed threshold value (first “switching speed”) is reached, a switch is made from a control with the aid of a deterministic setpoint actuating torque to a control in which the setpoint actuating torque is generated with the aid of the speed controller.

[0020] If the actual speed reaches or exceeds a predetermined second switching speed, determining the actual angle and the actual speed by means of EMK includes, in particular, when reaching a second speed threshold (second “switching speed”), switching from determining the actual angle and the actual speed by means of high-frequency injection or a high-frequency injection method to determining the actual angle and the actual speed by means of EMK (“electric motor force”) or an EMK method. EMK can also be referred to as BEMF (“back electromotive force”).

[0021] In one embodiment, the HFI method and / or the (“Electric Motor Force”) method can be implemented in a corresponding observer. The observer can be designed, for example, as a Romberg observer, a Kalman observer, etc. or can have a Romberg observer, a Kalman observer, etc.

[0022] In one embodiment, the second switching speed is greater than the first switching speed, so that the speed is first switched to speed regulation and then switched to determining the actual angle and the actual speed by means of the EMK. However, the method is not limited to this, and the second switching speed can also be less than the first switching speed. There is also an extension scheme that the first switching speed is consistent with the second switching speed.

[0023] As the set adjustment torque, a value corresponding to the physical meaning of the torque can be used. Alternatively, at least one value can be used as the set adjustment torque, the at least one value similarly describing the physical meaning of the torque for the motor, such as a set current in a d / q system. Therefore, exemplarily, the torque value (or equivalently, the set current in a d / q system) can be output as a deterministic set adjustment torque.

[0024] One embodiment is that a control signal for supplying current to a coil of a BLDC drive motor is generated by means of a vector controller from a set actuating torque and an actual angle, wherein:

[0025] - when the actual speed has not yet reached or exceeded the first switching speed, the setpoint actuating torque supplied to the vector controller is a deterministic setpoint actuating torque, and

[0026] When the actual rotational speed ω reaches or exceeds the first switching speed, the set actuating torque supplied to the vector controller is the actuating variable of the speed controller, the command variable of which is Corresponding to the set speed, the feedback parameter of the speed regulator Corresponds to the actual speed.

[0027] Vector control (Field-Oriented Control, FOC) can include space vector modulation (Space Vector PWM, SVPWM). Vector control uses, in particular, a set current in a d / q system, in particular a set I d Current and setting I q Current as set variable. These set currents in the d / q system can be calculated from the set actuating torque and can correspond to the set actuating torque with high accuracy. That is, the set current in the d / q system can be regarded as a representative of the set actuating torque in the d / q system. One development is that the vector controller outputs measured or internally calculated variables as measured variables for the observer, such as measured motor currents and / or voltages and / or currents in the rotor-related α / β system.

[0028] One embodiment is that the deterministic setpoint actuating torque is generated by means of a signal transmitter. The signal transmitter generates an output signal corresponding to the deterministic setpoint actuating torque based on an input value, for example a value calculated in a formula or retrieved from a data memory. In particular, the signal transmitter is not a controller and can therefore also be referred to as a "non-controllable" signal transmitter.

[0029] One embodiment provides that the deterministic setpoint actuating torque is a constant setpoint actuating torque. This can advantageously be implemented particularly easily.

[0030] In one embodiment, the deterministic setpoint actuating torque is a temporal profile of the setpoint actuating torque or has more than two different values ​​that follow one another in time. This achieves the advantage that the start-up can be carried out particularly smoothly.

[0031] In one embodiment, the deterministic set adjustment torque depends on at least one pressure present in a reciprocating piston compressor driven by a BLDC drive motor of a household appliance or a variable derived therefrom, such as a pressure ratio. Advantageously, the set adjustment torque can thus be adapted in a targeted manner to the pressure or pressures in the reciprocating piston compressor and thus to the desired load pressure. This in turn enables a particularly smooth start. A further advantage of the method when used with a reciprocating piston compressor is that, when starting with a deterministic set adjustment torque, "sticking" is avoided during the first compression, more precisely, "sticking" is also avoided in the case of high load ratios.

[0032] In one embodiment, the MTPA (“Maximum Torque per Ampere”) logic is connected before the vector control logic, and the MTPA logic converts the set adjustment torque into the set I d Current and setting I q The current can be transmitted as an input variable, for example, to the vector control logic. This is advantageous so that the BLDC motor can be operated particularly efficiently starting from the set actuating torque. For the same purpose, a development is to integrate the field weakening logic into the MTPA logic.

[0033] One embodiment is that the reciprocating piston compressor is driven or drivable by means of a BLDC drive motor. The method can be used particularly advantageously for this purpose, since in this case, during startup, components of the household appliance are mechanically loaded and the probability of generating disturbing noises is particularly high.

[0034] One development is that the reciprocating piston compressor is a component of a refrigeration circuit. Then, one configuration is that the household appliance is a refrigeration appliance, such as a refrigerator, a freezer or a combination thereof.

[0035] One development is that the reciprocating piston compressor is a component of a heat pump. In particular, in this case, the household appliance can be a laundry processing appliance such as a washing machine, a laundry dryer or a combination thereof (washing and drying machine). However, the household appliance can also be a dishwasher.

[0036] One development consists in that a laundry drum of a laundry treatment appliance is driven or drivable by means of a BLDC drive motor.

[0037] This object is also achieved by a domestic appliance having a BLDC drive motor, wherein the domestic appliance is configured to carry out the method as described above. The domestic appliance can be designed similarly to the method and vice versa and has the same advantages.

[0038] The domestic appliance may be, for example, a refrigeration appliance in which a compressor of a refrigeration circuit, in particular a reciprocating piston compressor, can be driven by means of a BLDC drive motor.

[0039] In one embodiment, the BLDC drive motor is controllable by means of a converter circuit and the converter circuit is configured to carry out the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The characteristics, features and advantages of the invention described above and the manner in which they are achieved become clearer and more clearly understandable in conjunction with the following exemplary description of an embodiment, which is explained in more detail in conjunction with the drawings.

[0041] Figure 1 A sketch showing a household appliance in the form of a refrigerator in side view as a cross-sectional representation;

[0042] Figure 2 Shown for drive Figure 1 Possible functional structures of a motor control of a drive motor of a household appliance;

[0043] Figure 3 Shown in more detail Figure 2 Possible functional structures of vector control of motor control;

[0044] Figure 4 A possible sequence of a method for starting a drive motor is shown. DETAILED DESCRIPTION

[0045] Figure 1A sketch of a household appliance in the form of a refrigerator 1 is shown in a side view as a sectional illustration. The refrigerator 1 has a refrigerated space 2, the charging opening of which can be closed at the front by means of a door 3. The refrigerator 1 is controlled by means of a control device 4. In an extension, the control device 4 can control a BLDC drive motor 5 of a compressor or gas compressor 6 of a refrigeration circuit. Here, the compressor 6 is designed as a reciprocating piston compressor. The BLDC drive motor 5 has a rotor 7 used as a drive shaft and can be controlled by means of a motor controller 8, which generates a control signal for supplying current to the coils of the BLDC drive motor 5. The motor controller 8 can be a component of the BLDC drive motor 5, for example integrated in a converter circuit 9 of the BLDC drive motor 5 by hardware and / or software, in particular integrated in a controller 10 of the converter circuit 9, see Figure 2 Alternatively, the converter circuit 9 or the entire motor controller 8 can also be integrated in the control device 4 of the refrigerated container 1 .

[0046] Figure 2 A possible functional structure of the motor control 8 based on different functional blocks is shown.

[0047] One of the functional blocks is a speed regulator 11, which adjusts the speed of the rotor 7 according to the set speed ω. ref And the actual speed ω to calculate the set adjustment torque M ref，stell as an adjustment parameter.

[0048] Another of the functional blocks is a signal transmitter 12 which outputs a deterministic setpoint actuating torque M independently of the actual rotational speed ω. ref，det The deterministic setting adjustment torque M ref，det It can be constant or can also vary over time. In particular, the deterministic setting of the adjustment torque M ref，det Can be parameterized.

[0049] The MTPA logic 13 may also include a field weakening or “field-weakening” logic, which, based on the input setpoint actuating torque M ref Based on the calculation of the setting I from the d / q system d Current I d,ref and Setting I q Current I q,ref The equivalent pair of MTPA logic 13 is input to the vector controller 14. As schematically indicated by the switch symbol, the set control torque M ref Alternatively, the set actuating torque M output from the speed regulator 11 ref，stell , or the deterministic setting adjustment torque M output from the signal transmitter 12ref，det .

[0050] The vector regulator 14 is set by the rotor 7 d Current I d，ref 、Set I q Current I q，ref And the control signal for supplying current to the coil of the BLDC drive motor 5 is calculated from the actual angle θ.

[0051] The motor controller 8 further comprises an observer 15, for example a Romberg observer, which receives an input or measured variable B from the vector controller 14 and calculates or estimates the actual angle θ and the actual speed ω of the rotor 7 from the input or measured variable B. The actual angle θ is transmitted to the vector controller 14 and the actual speed ω is transmitted to the speed controller 11.

[0052] Here, the observer 15 includes an HFI (high frequency injection) observer 16, which determines (especially estimates) the actual angle θ and the actual rotational speed ω from the measured variable B in the form of the motor current (the motor current has a high-frequency component generated by the high-frequency injection). The observer 15 also includes an EMK observer 17, which determines (especially estimates) the actual angle θ and the actual rotational speed ω from the measured variable B in the form of the transformed measured motor current and the motor voltage calculated in the vector controller 14 via the EMK.

[0053] Figure 3 A possible more detailed configuration of the vector controller 14 and the observers 16 and 17 is shown.

[0054] First, the setting I supplied from the MTPA logic 13 d Current I d，ref and actual I d Current I d Produce a difference, and similarly generate setting I q Current I q，ref and actual I q Current I q These differences are fed into a corresponding regulator 19, such as a PI regulator. The regulator 19 can also be called a current regulator. The controller 19 outputs a voltage V d or V q , the V d or V q is passed to the inverse Park transform 20.

[0055] Inverse Park transformation 20 is obtained by voltage V d and V q And the actual angle θ calculates the voltage V in the α / β system α and V βAnd it is passed to the space vector modulation 21 (English: "Space Vector PWM", SVPWM). The space vector modulation 21 generates a control signal GS, for example, a gate signal for a transistor, for a four-quadrant regulator 22, which no longer needs to be part of the vector controller 14. The four-quadrant regulator 22 supplies current to the BLDC drive motor 5 according to the control signal GS.

[0056] Furthermore, the vector controller 14 comprises a Clarke transformation 23 which transforms the measured motor current I a , I b , I c Converted to the current I in the α / β system α , I β , knowing the actual angle θ, the current I α , I β It is then converted to the actual I by means of Park transformation 24 d Current I d and actual I q Current I q Blocks 23 and 24 may also be collectively referred to as Clarke-Park transforms. d Current I d and actual I q Current I q With setting I d Current I d，ref Or set I q Current I q，ref are returned together to generate the difference.

[0057] The HFI observer 16 receives the motor current I which is still loaded with high frequency from the vector controller 14 a , I b , I c As the measured variable B, the actual angle θ and the actual rotation speed ω of the rotor 7 are estimated therefrom. In an extended solution, the HFI observer 16 may include a Romberg observer, a Kalman observer, and the like.

[0058] The EMK observer 17 obtains the current I in the α / β system from the vector regulator 14 α , I β and the voltage V in the α / β system α , V β As measured variable B, the actual angle θ and the actual rotational speed ω of the rotor 7 are estimated therefrom. In a further development, the EMK observer 17 can be designed as a Romberg observer, a Kalman observer or the like.

[0059] Figure 4A possible embodiment showing how the motor controller 8 can perform the starting or actuation of the BLDC drive motor 5:

[0060] It is assumed that the BLDC drive motor 5 is at rest in step S0 , in which its actual rotational speed ω is zero, for example because no current is flowing through it.

[0061] In step S1, the HFI signal is applied to the motor current I a , I b , I c and the motor current I a , I b , I c The actual angle θ and the actual rotational speed ω of the rotor 7 are determined by means of the HFI observer 16, in particular periodically, for example with a period duration T of approximately 250 μs. A In this case, it is advantageous if ω=0 can also be detected by means of a high-frequency injection method.

[0062] In step S2, a deterministic setpoint actuating torque M is generated by means of the signal transmitter 12. ref，det (That is, M ref =M ref，det Applicable) and output it to the MTPA logic 13. Therefore, the calculation setting I d Current I d and Setting I q Current I q，ref and forwards it to the vector controller 14. As already explained above, the vector controller 14 generates the control signal GS from these and from the actual angle θ estimated by the HFI observer 16 and also outputs the measured variable B for the HFI observer 16.

[0063] In step S3 , it is checked whether the actual rotational speed ω determined by means of the HFI observer 16 reaches or exceeds a first threshold value, ie, the first switching rotational speed. If not (“N”), the process returns to step S1 .

[0064] In steps S1 to S3 , the rotation speed regulator 11 is not used.

[0065] If yes ("J"), the process proceeds to step S4, in which the deterministic setpoint torque M generated by means of the signal transmitter 14 is no longer set. ref，det The output to the MTPA logic 15 is the set adjustment torque M calculated by the speed regulator 11. ref，stell , that is, apply M ref，sstell .

[0066] Similar to step S2, the MTPA logic 13 is composed of M ref =M ref，stell Calculation Settings I d Current I d，ref and Setting I q Current I q，ref This is passed on to the vector controller 14 , which generates therefrom and from the actual angle θ estimated by the HFI observer 16 a control signal GS and outputs a measured variable B for the HFI observer 16 .

[0067] In step S5, it is checked whether the actual speed ω determined by means of the HFI observer 16 reaches or exceeds the second threshold value, ie the second switching speed. If not ("N"), then return to step S4. However, if this is the case ("J"), then go to step S6.

[0068] In step S7 , the actual angle θ and the actual rotational speed ω are now determined with the aid of the EMK observer 17 , but otherwise proceed in a manner analogous to step S4 .

[0069] Naturally, the invention is not limited to the embodiments shown.

[0070] Therefore, in Figure 4 In the embodiment described in , it is assumed that the second switching speed is greater than the first switching speed. However, alternatively, the first switching speed may be greater than the second switching speed, or the two switching speeds may be the same.

[0071] Furthermore, the MTPA logic 13 can also be omitted. In this case, the setting torque M can be adjusted by means of other calculation criteria. ref To calculate the setting I d Current I d and Setting I q Current I q , or it can be converted in the vector controller 14 , or it can be directly output from the speed controller 11 and the signal transmitter 12 .

[0072] Furthermore, instead of the observer 15 , the actual angle θ and / or the actual rotational speed ω may be determined by means of sensors, for example by means of at least one Hall sensor installed in the BLDC drive motor 5 .

[0073] In general, “a” or “an” may be understood as one or more, especially in the sense of “at least one” or “one or more” etc., as long as this is not explicitly excluded, for example by the expression “exactly one” etc.

[0074] Furthermore, numerical specifications may include exactly the specified numeral as well as the customary tolerance ranges, unless this is explicitly excluded.

[0075] Reference numerals list

[0076] 1 Refrigerator

[0077] 2 Refrigerated Space

[0078] 3 doors

[0079] 4 Control device

[0080] 5BLDC drive motor

[0081] 6. Compressor

[0082] 7 Rotors

[0083] 8 Motor Controller

[0084] 9 Commutation circuit

[0085] 10 Controller

[0086] 11 Speed ​​regulator

[0087] 12Signal transmitter

[0088] 13MTPA Logic

[0089] 14 Vector Regulator

[0090] 15Observer

[0091] 16 High frequency injection observer

[0092] 17EMK Observer

[0093] 19PI regulator

[0094] 20 Inverse Park Transform

[0095] 21 Space Vector Modulation

[0096] 22 Four-quadrant regulator

[0097] 23 Clarke Transform

[0098] 24 Park Transform

[0099] B Measurement parameters

[0100] GS control signal

[0101] I a , I b , I c Motor current

[0102] I d Actual I d Current

[0103] Iq Actual I q Current

[0104] I d，ref Setting I d Current

[0105] I q，ref Setting I q Current

[0106] M ref Setting adjustment torque

[0107] M ref，det Deterministic setting of adjustment torque

[0108] M ref，stell Setting adjustment torque

[0109] S0-S6 Method Steps

[0110] Vα is the voltage in the α / β system

[0111] Vβ is the voltage in the α / β system

[0112] V d Voltage in a d / q system

[0113] V q Voltage in a d / q system

[0114] ω Actual speed

[0115] ω ref Set speed

[0116] θ Actual angle

Claims

1. A method (S0-S6) for operating a household appliance (1), in which, for starting a BLDC drive motor (5) of the household appliance (1), - Adjust the torque (M) with the help of deterministic settings ref，det ) regulates the actual rotational speed (ω) of the rotor (7) of the BLDC drive motor (5) from its stationary state, and determines the actual angle (θ) and the actual rotational speed (ω) of the rotor (7) by means of high-frequency injection; -When the actual speed (ω) reaches or exceeds the first switching speed, the actual speed (ω) is adjusted to the set speed (ω ref ) on, and When the actual rotational speed (ω) reaches or exceeds the second switching rotational speed, the actual angle (θ) and the actual rotational speed (ω) are determined from the EMK signal.

2. The method (S0-S6) according to claim 1, in which the second switching speed is greater than the first switching speed.

3. The method (S0-S6) according to any one of the preceding claims, in which the vector controller (12) is used to adjust the torque (M ref ) and the actual angle (θ) generate a control signal for passing current through the coil of the BLDC drive motor (5), wherein: - when the actual speed (ω) has not yet reached or exceeded the first switching speed, the set actuating torque (M ref ) is the deterministic set adjustment torque (M ref，det ); and - When the actual speed (ω) reaches or exceeds the first switching speed, the set actuating torque (M ref ) is the adjustment parameter (M) of the speed regulator (11) ref，stell ), the command parameter of the speed regulator corresponds to the set speed (ω ref ), and the feedback variable of the speed regulator corresponds to the actual speed (ω).

4. The method (S0-S6) according to any one of the preceding claims, in which the deterministic setting of the adjustment torque (M ref，det ) is generated with the aid of a signal transmitter (14).

5. The method (S0-S6) according to any one of the preceding claims, in which the deterministic setting of the adjustment torque (M ref，det ) is the constant set adjustment torque.

6. The method (S0-S6) according to any one of claims 1 to 4, in which the deterministic setting adjustment torque (M ref，det ) is the time variation curve of the set adjustment torque.

7. The method (S0-S6) according to any one of the preceding claims, in which the deterministic setting adjustment torque (M ref，det ) depends on at least one pressure present in a reciprocating piston compressor of the household appliance (1) driven by the BLDC drive motor (5) or on a variable derived from the pressure.

8. The method (S0-S6) according to any one of claims 3 to 7, wherein the MTPA logic (15) is connected before the vector control logic (12), and the MTPA logic sets the set adjustment torque (M ref ) is converted to setting I d Current (I d，ref ) and converted to setting I q Current (I q，ref ) and passes it as an input parameter to the vector control logic (16).

9. The method (S0-S6) according to any one of the preceding claims, in which, when the BLDC drive motor (5) is at rest, its actual rotational speed (ω) is zero.

10. A household appliance (1) having a BLDC drive motor (5), wherein: The domestic appliance (1) is configured to carry out a method (S0-S6) according to any one of the preceding claims.

11. The household appliance (1) according to claim 10, wherein: A reciprocating piston compressor (6) can be driven by means of the BLDC drive motor (5).

12. The household appliance (1) according to any one of claims 10 to 11, wherein: The household appliance (1) is a refrigeration appliance, in particular a refrigerator.

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