CN117811457A

CN117811457A - Control circuit, method, device, electronic equipment and storage medium for motor

Info

Publication number: CN117811457A
Application number: CN202311318009.2A
Authority: CN
Inventors: 张勤建; 姚辉军; 吴立建; 张振洋; 王文婷; 张兵; 王浩
Original assignee: Zhejiang University ZJU; Jiaxipera Compressor Co Ltd
Current assignee: Zhejiang University ZJU; Jiaxipera Compressor Co Ltd
Priority date: 2023-10-11
Filing date: 2023-10-11
Publication date: 2024-04-02

Abstract

The invention provides a control circuit, a control method, a control device, an electronic device and a storage medium of a motor. The control circuit includes: the controller, the first switch and the second switch; the motor is connected with a single-phase alternating current power grid through a first switch; the motor is connected with the controller through a second switch; the controller is respectively connected with the first switch and the second switch, responds to a control signal of the motor, determines a target rotating speed matched with the type of the control signal, and controls the switching states of the first switch and the second switch according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to switch the running state of the motor; the running states comprise a grid-connected running state and an off-grid running state. The controller determines the target rotating speed of the motor according to the type of the control signal, so that the motor can be flexibly switched between a grid-connected running state and a grid-off running state according to the control signals of different types, and the increase of the energy consumption of the controller of the motor caused by the fact that the motor runs in a single running state all the time can be avoided.

Description

Control circuit, method, device, electronic equipment and storage medium for motor

Technical Field

The present invention relates to the field of motor control technologies, and in particular, to a method and a system for controlling a motor, an electronic device, and a storage medium.

Background

Nowadays, a refrigeration home appliance represented by a refrigerator generally uses a motor for refrigeration, and as the home appliance starts to pursue efficient weight reduction of the motor, a motor system driven by a variable-frequency permanent magnet synchronous motor gradually highlights its advantages. In addition, the motor running speed condition of the motor is about 1000-4500rpm, wherein the light-load low-speed working condition belongs to the common working condition, the highest efficiency of a motor system is generally required, and the running of the motor is controlled in a variable-frequency speed-regulating mode by a controller. However, the control mode of variable frequency speed regulation can cause the increase of energy consumption of the controller and the loss of the motor.

Disclosure of Invention

The invention aims to overcome the defects that the energy consumption of a controller is increased and the loss of a motor is caused by a control mode of variable frequency speed regulation of the motor in the prior art, and provides a control circuit, a method, a device, electronic equipment and a storage medium of the motor.

The invention solves the technical problems by the following technical scheme:

in a first aspect, there is provided a control circuit for an electric machine, the control circuit comprising: the controller, the first switch and the second switch;

The motor is connected with a single-phase alternating current power grid through the first switch;

the motor is connected with the controller through the second switch;

the controller is respectively connected with the first switch and the second switch, responds to a control signal of the motor, determines a target rotating speed matched with the type of the control signal, and controls the switch states of the first switch and the second switch according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to switch the running state of the motor and achieve the control target of the control signal; the operation states comprise a grid-connected operation state and an off-grid operation state; the motor in the grid-connected operation state is directly powered by the single-phase alternating current power grid; and the motor in the off-grid running state is powered by the output of the controller.

In a second aspect, there is provided a control method of an electric motor, the control method of the electric motor including:

determining a target rotational speed that matches a type of the control signal in response to the control signal of the motor;

switching the running state of the motor according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to achieve the control target of the control signal; the operation states comprise a grid-connected operation state and an off-grid operation state; the motor in the grid-connected operation state is directly powered by the single-phase alternating current power grid; and the motor in the off-grid running state is powered by the output of the controller.

In a third aspect, there is provided a control device of an electric motor, the control device of an electric motor including:

a determining module, responsive to a control signal of the motor, for determining a target rotational speed of the motor corresponding to the control signal;

the control module is used for switching the running state of the motor according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to achieve the control target of the control signal; the operation states comprise a grid-connected operation state and an off-grid operation state; the motor in the grid-connected operation state is directly powered by the single-phase alternating current power grid; and the motor in the off-grid running state is powered by the output of the controller.

In a fourth aspect, there is provided an electronic device comprising a memory, a processor and a computer program stored on the memory for running on the processor, the processor implementing the method of controlling a motor according to the second aspect when executing the computer program.

In a fifth aspect, there is provided a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method of controlling a motor according to the second aspect.

On the basis of conforming to the common knowledge in the field, the above preferred conditions can be arbitrarily combined to obtain the preferred examples of the invention.

The invention has the positive progress effects that: the controller determines the target rotating speed of the motor according to the type of the control signal, and controls the motor to switch between a grid-connected running state and a grid-off running state according to the target rotating speed and the working frequency of the single-phase alternating current power grid, so that the motor can flexibly switch between the grid-connected running state and the grid-off running state according to different types of the control signals; on one hand, the method has the advantages that no intervention of a controller is needed during grid-connected operation, the efficiency is high, no controller loss exists, the increase of the energy consumption of the controller of the motor caused by the fact that the motor always operates in a single operation state can be avoided, if the controller has a problem, the controller can also cut into the grid-connected operation state, the continuous operation of the motor is ensured, and certain fault tolerance capability is realized; on the other hand, the motor is directly powered by a single-phase alternating current power grid in the grid-connected mode, the single-phase alternating current power grid has good sine property and less harmonic wave, and the loss of the motor can be reduced.

Drawings

Fig. 1 is a circuit diagram of a control circuit of a motor according to an exemplary embodiment of the present invention;

fig. 2 is a circuit diagram of a controller included in a control circuit of a motor according to an exemplary embodiment of the present invention;

fig. 3 is a circuit diagram of a voltage conversion circuit of a controller included in a control circuit of a motor according to an exemplary embodiment of the present invention;

Fig. 4 is a circuit diagram of a voltage conversion circuit of a controller included in a control circuit of another motor according to an exemplary embodiment of the present invention;

fig. 5 is a circuit diagram of a control circuit of another motor according to an exemplary embodiment of the present invention;

fig. 6 is a circuit diagram of a control circuit of another motor according to an exemplary embodiment of the present invention;

FIG. 7 is a schematic diagram of a rotational speed condition of a control circuit of a motor for running in parallel according to an exemplary embodiment of the present invention;

FIG. 8 is a schematic diagram of a rotational speed condition of a control circuit of another motor according to an exemplary embodiment of the present invention for operating a grid-tie;

FIG. 9 is a schematic diagram of a rotational speed condition of a control circuit of another motor according to an exemplary embodiment of the present invention for operating a grid-tie;

FIG. 10 is a schematic diagram of a rotational speed condition of a control circuit of another motor according to an exemplary embodiment of the present invention for operating a grid-tie;

FIG. 11 is a schematic diagram of a rotational speed condition of a control circuit of another motor according to an exemplary embodiment of the present invention for operating a grid-tie;

FIG. 12 is a schematic diagram of a rotational speed condition of a control circuit for another motor according to an exemplary embodiment of the present invention for operating a grid-tie;

Fig. 13 is a flowchart of a control method of a motor according to an exemplary embodiment of the present invention;

fig. 14 is a schematic block diagram of a control device for an electric motor according to an exemplary embodiment of the present invention;

fig. 15 is a schematic structural diagram of an electronic device according to the present embodiment.

Detailed Description

The invention is further illustrated by means of the following examples, which are not intended to limit the scope of the invention.

The embodiment of the invention provides a control circuit of a motor, which is a motor with the capacity of running at the working frequency of single-phase alternating current and the capacity of running at variable frequency, such as a single-phase permanent magnet motor with the number of poles equal to the number of slots. The control circuit of the embodiment of the invention does not limit the operation mode of the motor, and is suitable for motors operated in a stepless speed regulation mode and motors operated in a stepped speed regulation mode.

Referring to fig. 1, the control circuit includes: a controller 11, a first switch K1 and a second switch K2. The motor 12 is connected to the single-phase ac power grid S through the first switch K1, and the motor 12 is connected to the controller 11 through the second switch K2. The controller 11 is also connected to the first switch K1 and the second switch K2, respectively. It should be noted that, in this embodiment, the connection manner of the devices may be wired connection or wireless connection, which is not particularly limited to this embodiment of the present invention.

The controller 11 determines a target rotation speed matched with the type of the control signal in response to the control signal of the motor 12, and controls the switching states of the first switch K1 and the second switch K2 according to the target rotation speed and the operating frequency of the single-phase alternating current network to switch the operating state of the motor 12, thereby achieving the control target of the control signal.

The operation states of the motor 12 include a grid-connected operation state and an off-grid operation state. The motor in the grid-connected operation state is directly powered by a single-phase alternating current power grid; the motor in the off-grid running state is powered by the output of the controller. The switch state includes closed and open.

The control signal is a signal transmitted by an external device or an upper system of the motor 12, and may include, but is not limited to, at least one of the following: voltage regulation signals, frequency regulation signals, rotation speed regulation signals, temperature regulation signals, refrigerating capacity regulation signals and the like. It will be appreciated that the type of control signal for the motor 12 will vary depending on the actual application scenario of the motor 12. The application scenario of the motor 12 may include, but is not limited to: the refrigerator motor 12 is driven to operate, and is used for smoke exhaust of a range hood, air conditioning refrigeration and the like.

In the embodiment of the invention, the controller 11 determines the target rotating speed of the motor 12 according to the type of the control signal, and controls the motor 12 to switch between the grid-connected running state and the off-grid running state according to the target rotating speed and the working frequency of the single-phase alternating current power grid, so that the motor 12 can flexibly switch between the grid-connected running state and the off-grid running state according to different types of control signals; on one hand, the method has the advantages that no intervention of a controller is needed in a grid-connected mode, the efficiency is high, no controller loss exists, the increase of the energy consumption of the controller 11 of the motor 12 caused by the fact that the motor 12 always operates in a single operation state can be avoided, if the controller has a problem, the method can also cut into the grid-connected operation state, the motor can be guaranteed to continue to operate, and certain fault tolerance capability is achieved; on the other hand, in the grid-connected mode, the motor is directly powered by the single-phase alternating-current power grid, the single-phase alternating-current power grid has good sine property and less harmonic waves, and compared with the PWM wave adopted for frequency conversion working condition power supply, the loss of the motor can be reduced.

In one embodiment, when the target rotation speed of the motor accords with the working frequency of the single-phase alternating current power grid, the first switch K1 is closed, the second switch K2 is opened, the controller 11 does not supply power to the motor 12 any more, the single-phase alternating current power grid supplies power to the motor 12, the motor 12 is driven to operate, and the motor 12 is in a grid-connected operation state. When the target rotation speed of the motor 12 does not meet the working frequency of the single-phase alternating-current power grid, namely, does not meet the grid-connected condition, the first switch K1 is opened, the second switch K2 is closed, the single-phase alternating-current power grid does not supply power to the motor 12 any more, the controller 11 supplies power to the motor 12, the motor 12 is driven to operate, and the motor 12 is in a grid-off operation state. When both the first switch K1 and the second switch K2 are turned off, the motor 12 is in a stopped state.

It will be appreciated that the motor is to be operated in a grid-connected condition, and that the current voltage of the motor is required to be consistent with the grid voltage in addition to the target rotational speed being required to meet the operating frequency conditions of the single-phase ac grid.

Wherein the first switch K1 and the second switch K2 may be, but not limited to, solid state relay or electromagnetic relay.

In the embodiment of the invention, as long as the target rotation speed of the motor 12 accords with the working frequency of the single-phase alternating current power grid, the single-phase alternating current power grid supplies power to the motor 12 to drive the motor 12 to operate, and the motor 12 is in a grid-connected operation state, so that the energy consumption of the controller 11 of the motor 12 can be reduced as much as possible. When the target rotation speed of the motor 12 does not accord with the working frequency of the single-phase alternating current power grid, the controller 11 is switched to supply power to the motor 12, the motor 12 is driven to operate, and the motor 12 is in an off-grid operation state, so that the motor 12 effectively operates.

In one embodiment, referring to fig. 1, L1 and L2 are power supply lines of the single-phase ac power grid S, the controller 11 is connected to the single-phase ac power grid S through lines L3 and L4, the controller 11 is further connected to the motor 12 through lines L5, L6, and the second switch K2, and the motor 12 is further connected to the single-phase ac power grid S through lines L7, L8, and the first switch K1. When the second switch K2 is closed, the controller 11 converts the electric energy of the single-phase ac power grid into electric energy satisfying the operation of the motor 12 at the target rotational speed, and supplies power to the motor 12.

In this embodiment, the controller 11 is directly powered by the single-phase ac power grid, and no additional power source is needed for the controller 11, so that the cost of the control circuit of the motor 12 can be saved.

In one embodiment, referring to fig. 2, the controller 11 includes: a voltage conversion circuit 111, a driving circuit 112, and a signal processing module 113. The input end of the voltage conversion circuit 111 is connected to a single-phase alternating current power grid, the output end of the voltage conversion circuit 111 is connected to the input end of the driving circuit 112, and the output end of the driving circuit 112 is connected to the motor 12 through the second switch K2. The signal processing module 113 is connected to the driving circuit 112, the first switch K1, and the second switch K2, respectively.

The voltage conversion circuit 111 is used to convert the alternating current of the single-phase alternating current network into direct current.

The voltage conversion circuit 111 shown in fig. 2 is a bridge type uncontrolled rectifying circuit, which rectifies alternating current into direct current to supply power to the driving circuit 112, and in this circuit structure, when the voltage of the alternating current is U, the rectified direct current voltage isU _dio Is the terminal voltage at which the diode is closed.

In addition to the voltage conversion circuit 111 shown in fig. 2, the voltage conversion circuit 111 may be realized by a full-wave rectification circuit structure with an autotransformer shown in fig. 3, which can realize an increase in the bus voltage after rectification. The voltage conversion circuit 111 may also be implemented by a full-wave rectifying circuit structure of the voltage doubling structure shown in fig. 4, where the voltage doubling structure may implement doubling of the rectified bus voltage, or may implement outputting the bus voltage to be any multiple of the voltage amplitude of the input terminal by adopting a similar structure.

The drive circuit 112 is used to convert the direct current into alternating current for operation of the power supply 12.

The signal processing module 113 is configured to determine a target rotation speed that matches a type of the control signal, and control the switching states of the first switch K1 and the second switch K2 according to the target rotation speed and an operating frequency of the single-phase ac power grid.

When the target rotation speed of the motor 12 accords with the working frequency of the single-phase alternating-current power grid, the signal processing module 113 controls the first switch K1 to be closed and the second switch K2 to be opened. When the target rotation speed of the motor 12 does not accord with the working frequency of the single-phase alternating-current power grid, the signal processing module 113 controls the first switch K1 to be opened and the second switch K2 to be closed.

In this embodiment, if one of the voltage conversion circuit, the driving circuit and the signal processing module has a problem, the motor can be switched into a grid-connected operation state, so that the motor can be ensured to continue to operate, and certain fault tolerance capability is provided.

In one embodiment, the drive circuit 112 includes a switching tube. The switching tube can be realized by one of a MOS tube, a triode and a transistor.

Referring to fig. 6, the control circuit further includes a voltage acquisition module 13. The voltage acquisition modules are respectively connected with the single-phase alternating current power grid and the controller 11.

The voltage acquisition module is used for acquiring a voltage signal of the single-phase alternating current power grid and sending the voltage signal to the controller 11, so that the controller 11 controls the switching state of a switching tube included in the driving circuit 112 according to the voltage signal, a control signal of the motor 12 and operation data of the motor 12, and the driving circuit 112 converts direct current into alternating current which meets the operation of the motor 12 at a target rotating speed. For a specific control procedure of the switching state of the switching tube, refer to the description of the related art, and will not be described herein.

Wherein the voltage signal includes, but is not limited to, amplitude, frequency, phase, etc. The operational data of the motor 12 includes at least one of the following parameters: actual rotational speed, rotor position, phase (line) voltage for each phase of the motor, amplitude of phase (line) current, phase, etc. The operational data of the motor 12 may be, but is not limited to, collected by at least one of the following: the motor is characterized by being acquired by sensors deployed on the motor 12, acquiring voltage and current on motor connecting lines, calculating the rotating speed and the rotor position through an algorithm.

It should be noted that, the motor 12 is operated at the target rotational speed, which does not mean that the actual rotational speed of the motor 12 is completely equal to the target rotational speed, and is substantially equal to the target rotational speed, and when the difference between the actual rotational speed of the motor 12 and the target rotational speed is smaller than the difference threshold, it is determined that the motor 12 is operated at the target rotational speed. The difference threshold can be determined according to the actual situation.

It will be appreciated that when the driving circuit 112 adopts the H-bridge structure shown in fig. 2, the second switch K2 may be omitted. When all the four switching transistors in the driving circuit 112 are turned off, the state is equivalent to the state in which the second switch K2 is turned off. When the first switch K1 is opened, the four switching transistors of the driving circuit 112 are operated, which is equivalent to a state in which the second switch K2 is closed.

In one embodiment, referring to fig. 5, the controller 11 includes: a voltage conversion circuit 111, a driving circuit 112, a signal processing module 113, and a switch control circuit 114. The signal processing module 113 gives on-off signals of the first switch K1 and the second switch K2 to the switch control circuit 114, so that the switch control circuit 114 controls the on-off states of the first switch K1 and the second switch K2 according to the on-off signals given by the signal processing module 113.

In one embodiment, a dc power source (e.g., a battery) is additionally provided to supply power to the controller 11, that is, the controller 11 is connected to the dc power source through the lines L3 and L4, the controller 11 of this embodiment may omit the voltage conversion circuit 111, and the controller converts the dc power provided by the dc power source into the electric energy satisfying the operation of the motor 12 at the target rotation speed to supply power to the motor 12.

In this embodiment, by providing a dc power supply, the controller 11 does not need to convert ac power into dc power, and the voltage conversion circuit 111 can be omitted, so that the power consumption of the controller 11 is reduced, and the structure of the controller 11 is simplified.

In one embodiment, the type of control signal is characterized by the frequency and/or duty cycle of the control signal, from which the controller 11 determines the target rotational speed.

For example, when the control signal is a single frequency signal f, the frequency signal may be obtained by signal sampling processing, and the controller 11 calculates the target rotation speed n by the following formula:

n＝f×k ₁ 。

wherein k is ₁ Representing the conversion factor, is a positive number and may be set to, but is not limited to, 30.

In one embodiment, the control signal may be converted to the target rotational speed by an internally stored signal conversion rule. For example, when the control signal is a voltage signal, the period of the control signal can be judged according to the waveform of a section of continuous voltage signal, so that a frequency signal can be calculated, and a target rotating speed is calculated according to the relation between the rotating speed and the frequency; when the control signal is a temperature signal, the required refrigerating capacity can be calculated according to the difference between the target temperature and the current temperature, the refrigerating capacity and the rotating speed are in positive correlation, and the target rotating speed can be obtained through proportional conversion.

For another example, when the control signal is a single square wave signal, the duty ratio is x, and the controller 11 calculates the target rotation speed n by the following formula:

n＝k ₂ x；

wherein k is ₂ The conversion coefficient is represented as a positive number.

In one embodiment, a square wave signal and a rotational speed n may be used _min And n _max And correspondingly establishing a conversion rule, and further converting the square wave signal into a target rotating speed.

The operation of the control circuit will be further described with reference to the control circuit controlling the motor 12 in the stepless speed regulation mode.

The controller 11 determines a rotation speed condition allowing the grid connection according to the working frequency of the single-phase ac power grid, when the target rotation speed falls into the rotation speed condition, the operation state of the control motor 12 is switched to the grid connection operation state or the off-grid operation state, and when the target rotation speed falls into the rotation speed condition, the control motor 12 is preferably operated in the grid connection operation state, from the viewpoint of saving the energy consumption of the controller 11. When the target rotation speed does not fall into the rotation speed condition, the operation state of the control motor 12 is switched to the off-grid operation state.

It will be appreciated that the performance parameters of the different models of motor 12 are different (including minimum speed, grid-tie speed, maximum speed, and threshold speed of motor 12), and that it is also desirable to combine the performance parameters of motor 12 in determining the speed condition. Specifically, the grid-connected rotational speed is determined according to the operating frequency of the single-phase ac power grid and the number of poles of the motor, and the rotational speed condition is determined according to the grid-connected rotational speed and the performance parameter of the motor 12.

The calculation formula of the grid-connected rotating speed is as follows:

n _s ＝f _g *60/p；

wherein f _g For the operating frequency of the single-phase ac network, p is the pole pair number, n, of the motor 12 _s The grid-connected rotating speed is the grid-connected rotating speed.

1. For the lowest rotation speed n _min And critical rotation speed n ₂ Equal motor 12, see fig. 7, if n _s ＝n _min ＝n ₂ (△n ₁ ＝△n ₂ ＝0，△n ₁ Characterization of n _s And n _min Delta n of the difference of (a) ₂ Characterization of n ₂ And n _s The difference of (c) and the rotational speed condition is that the target rotational speed is equal or nearly equal to the grid-connected rotational speed.

(1) If the target rotation speed n ^* ∈[0，n _min ) There are several cases:

when the motor 12 is in the shutdown state at present, the controller 11 does not act, and the shutdown state of the motor 12 is maintained;

when the motor 12 is in the grid-connected operation state currently, the controller 11 controls the first switch K1 to be switched off, and the single-phase alternating current power grid stops supplying power to the motor 12;

when the motor 12 is currently in the off-grid operation state, the controller 11 performs a speed regulation operation on the motor 12 until the rotation speed of the motor 12 reaches a low speed, and then controls the second switch K2 to be turned off.

(2) If n ^* ＝n _s Or the two are almost equal, the rotation speed conditions allowing the grid connection are met, and a plurality of processing modes can be selected:

the operation state of the control motor 12 in the first mode is the off-grid operation state:

when the motor 12 is currently in the shutdown stateIn the state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* The motor 12 is operated in an off-grid operation state;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n ^* The motor 12 is operated in an off-grid operation state;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n ^* And (5) performing later operation.

Mode two, the running state of the control motor 12 is a grid-connected running state, and the rotating speed is n ^* ＝n _s ：

When the motor 12 is in the shutdown state, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n _s When the voltage of the motor 12 meets the grid-connected condition, the first switch K1 is controlled to be closed, and the second switch K2 is controlled to be opened, so that the motor 12 operates in a grid-connected operation state;

when the motor 12 is in the grid-connected operation state at present, the controller 11 does not act, namely the current state of the motor 12 is kept unchanged;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s And controls the first switch K1 to be closed and the second switch K2 to be opened, so that the motor 12 operates in a grid-connected operation state.

It should be noted that, the first mode and the second mode may be selected according to the actual requirement, and of course, the second mode is preferably selected in view of saving the energy consumption of the controller 11.

(3) If n ^* >n _s The controller 11 controls the motor 12 to rotate at a speed n, which does not meet the speed condition for allowing the grid connection ^* The operation is in the off-line operation state:

when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* ；

When the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speedTo n ^* Operating;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n ^* And (5) running.

2. For the lowest rotation speed n _min Less than critical rotation speed n ₂ Referring to fig. 8, if n _s ＝n _min ＜n ₂ (△n ₁ ＝0，△n ₂ >0) The rotation speed condition is n ^* ∈[n _min ，n ₂ ]。

(1)n ^* ∈[0，n _min ) There are several cases:

when the motor 12 is in the off-grid running state currently, the controller 11 performs speed regulation operation on the motor 12 until the rotation speed of the motor 12 reaches a low speed, and then the second switch K2 is controlled to be turned off; or the controller 11 directly controls the second switch K2 to be turned off.

(2)n ^* ∈[n _min ，n ₂ ]According to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

Mode one, the control motor 12 is in an off-grid operating condition and has a rotational speed n ^* ：

When the motor 12 is in the stop state, the controller 11 controls the motor 12 to regulate the speed to n ^* And controls the second switch K2 to be closed, so that the motor 12 operates in the off-grid operation state;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the second switch K2 to be closed, the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n ^* The motor 12 is operated in an off-grid operation state;

Mode two, the operating state of the control motor 12 is a grid-connected operating stateThe rotation speed is n _s ：

When the motor 12 is in the stop state, the controller 11 controls the motor 12 to regulate the speed to n _s And controls the first switch K1 to be closed so that the motor 12 operates in a grid-connected operation state;

Mode three, if n ^* ＝n _s Or n ^* ＝n ₂ Either mode one or mode two operation may be selected. If n _s <n ^* <n ₂ The controller 11 is based on the step rotation speed n _x The motor 12 is controlled to regulate speed, the signal period is T, and the signal period contains (i+j) or (i+j+1) and the rotating speed n ^* ) The rotation speed, i is more than or equal to 1, j is more than or equal to 1, and is recorded as 0 to n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n ^* ，n ₁₊ ，…，n _j+ One of (2) and all > n _s : when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _x Off-line operation; when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n _x Off-line operation; when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x And (5) running.

When the step rotation speed n _x Is n _1- ，…，n _i- One of them is to make the following determinationBreaking:

a、n _x ＝0

when the motor 12 is currently in a stop state, the controller 11 does not act, and the motor 12 maintains the current state;

when the motor 12 is in the grid-connected operation state currently, the controller 11 controls the first switch K1 to be turned off;

When the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to be low, and then controls the second switch K2 to be turned off; or directly controls the second switch K2 to be opened.

b、n _x ＝n _s And requires motor 12 to be n _s Operating in a grid-connected operating state

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _s When the voltage of the motor 12 meets the grid-connected condition, the first switch K1 is controlled to be closed, and the second switch K2 is controlled to be opened, so that the motor 12 operates in a grid-connected operation state;

when the motor 12 is in the grid-connected operation state at present, the controller 11 does not act, and the motor 12 keeps the current state unchanged;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s After the controller 11 further controls the terminal voltage of the motor 12 to reach the grid-connected condition, the motor 12 is operated in a grid-connected operation state.

c、n _x ＝n _s And requires motor 12 to be n _s Operates in an off-line operation state

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _s Off-line operation;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be closed and the second switch K2 to be opened, and controls the motor 12 to regulate the speed to n _s Off-line operation;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s And (5) running.

d、n _x ≠n _s And n is _x ≠0

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _x Off-line operation;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _x Off-line operation;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x And (5) running.

It should be noted that, the modes one to three can be selected according to the actual requirement, and naturally, in consideration of saving the energy consumption of the controller 11, when the target rotation speed of the motor 12 meets the grid-connected condition, the motor 12 is preferentially controlled to be switched to the grid-connected operation state.

(3)n ^* >n ₂ The controller 11 controls the motor 12 to operate in the off-grid operating state at a rotational speed n:

when the motor 12 is in a stop state currently, the controller 11 controls the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n;

when the motor 12 is in a grid-connected operation state currently, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n-times operation;

When the motor 12 is currently in the off-grid operation state, the controller 11 controls the motor 12 to regulate speed to n-th operation.

3. For the lowest rotation speed n _min Less than or equal to critical rotation speed n ₂ Referring to fig. 9, if n _min <n _s ≤n ₂ (△n ₁ >0，△n ₂ Not less than 0), the rotation speed condition is the target rotation speed n ^* ∈[n _min ，n ₂ ]。

(1)n ^* ∈[0，n _min ) There are several cases:

(2)n ^* ∈[n _min ，n _s ]A variety of processing modes may be selected:

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* The motor 12 is operated in an off-grid operation state;

Mode two, the running state of the control motor 12 is a grid-connected running state, and the rotating speed is n _s ：

When the motor 12 is in a shutdown state currently, the controller 11 controls the first switch K1 to be closed, so that the motor 12 operates in a grid-connected operation state;

Mode three, if n ^* ＝n _min Or n ^* ＝n _s Either mode one or mode two operation may be selected. If n _min <n ^* <n _s The controller 11 is controlled based on the stepped rotation speed signalThe motor 12 is speed-regulated and has a signal period T, which includes (i+j) or (i+j+1), including a rotation speed n ^* ) The rotation speed, i is more than or equal to 1, j is more than or equal to 1, and is recorded as 0 to n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n _1- ，…，n _i- ，n ^* One of (n) _x =0 or all n _min ≤n _x <n _s )：

a、n _x ＝0

b、n _min ≤n _x <n _s

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n _x Off-line operation;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x And (5) off-line operation.

When the step rotation speed n _x Is n ₁₊ ，…，n _j+ One of the following is performed:

a、n _x ＝n _s and requires the motor 12 ton _s Operating in a grid-connected operating state

b、n _x ＝n _s And requires motor 12 to be n _s Operates in an off-line operation state

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n _s Off-line operation;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s And (5) off-line operation.

c、n _x ≠n _s

When the motor 12 is in the stop state, the controller 11 controls the motor 12 to regulate the speed to n _x Off-line operation;

when the motor 12 is currently in the grid-connected operation state, a grid-off command is executed, and the controller 11 controls the motor 12 to regulate the speed to n _x Off-line operation;

(3)n ^* ∈(n _s ，n ₂ ]According to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

Mode three, if n ^* ＝n _s Or n ^* ＝n ₂ Either mode one or mode two operation may be selected. If n _s <n ^* <n ₂ The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, the signal period is T, and the signal period contains (i+j) or (i+j+1) and contains the rotation speed n ^* ) The rotation speed, i is more than or equal to 1, j is more than or equal to 1, and is recorded as 0 to n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* Time, all rotational speedsThe total time of operation is T.

When the step rotation speed n _x Is n ^* ，n ₁₊ ，…，n _j+ One of (2), and n _x Are all greater than n _s Does not meet the grid connection condition:

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x And (5) off-line operation. When the step rotation speed n _x Is n _1- ，…，n _i- One of the following is performed:

a、n _x ＝0

when the motor 12 is currently in an off-grid operating condition, the controller11 control motor 12 speed to n _s And controls the first switch K1 to be closed and the second switch K2 to be opened.

d、n _x ≠n _s And n is _x ≠0：

When the motor 12 is in the stop state, the controller 11 controls the first switch K1 to be closed and controls the motor 12 to regulate the speed to n _x Off-line operation;

When n is ^* >n ₂ The controller 11 controls the motor 12 to operate in the off-grid operating state at a rotational speed n:

The operation of the control circuit will be further described with reference to the control circuit controlling the motor 12 in the step-wise governor mode.

Referring to fig. 10, it is assumed that the rotational speed of the motor 12 is in the operable interval [ n ] in the non-stop state _min ，n _max ]The internal classification is k stages, and the rotation speeds of the k stages are respectively n _v1 ，n _v2 ，……n _vk Wherein n is _v1 ≥n _min ，n _vk ≤n _max The set of k elements is denoted as V. The k-stage rotational speed is the operational rotational speed in the case of stepped speed regulation, the classification of which is determined by the upper layer system.

1. When (when)When the rotation speed condition allowing the grid connection is not met, the motor 12 can only work in the off-grid operation state. />

(1) If the target rotation speed n ^* ∈[0，n _min ) There are several cases:

(2)n ^* ≥n _min ：

Mode one, motor 12 ultimately operating in off-grid operation, with a target speed of n ^* ＝n _vx ，n _vx For the sum n in set V ^* The nearest rotational speed:

when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _vx The operation is in an off-line operation state;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _vx And (5) performing later operation.

Mode two, record 0 as set A; n is n _v1 ，…，n _vm Is composed of m elementsThe set is B, and B epsilon n _min ，n ^* ]；n _ve ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, and e=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to 1 and less than or equal to k-m, and the rotating speed n _1- ，……n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C. Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* And corresponding to the running delta T time, wherein the total running time of all rotating speeds is T.

It should be noted that, the set a and the set B are just classified for convenience of description. A target speed n may be run for different times with a number of speeds less than n and a number of speeds greater than n to simulate the condition of running at n all times.

When the step rotation speed n _x Is n _1- ，…，n _i- One of the following is performed:

a、n _x ＝0

b、n _x ≠0

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x Off-net transportAnd (3) row.

2. When n is _s When E is V, the motor 12 can work in the grid-connected operation state

1. Referring to FIG. 11, when n _min ≤n _v1 ＝n _s ≤n ₂ (△n ₁ ≥0，△n ₂ ≥0)

(1) If the target rotation speed n ^* ∈[0，n _min ) There are several cases:

(2)n*∈[n _min ，n _s ]According to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

the operation state of the control motor 12 in the first mode is a grid-connected operation state, and the rotation speed is n _s ：

When the motor 12 is currently in the grid-connected operation state, the controller 11 does not act, namely the current state of the motor 12 is kept unchanged;

Mode two, the running state of the control motor 12 is the off-grid running state, and the rotating speed is n _s ：

The mode precondition is n _min ≤n _v1 ＝n _s ≤n ₂ I.e. n _s First-stage rotational speed n, which is a stepped rotational speed _v1 Thus n is e n _min ，n _s ]At the time of the stepped rotation speed n _v1 I.e. n _s And (5) running.

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _s Off-line operation;

Mode three, if n ^* ＝n _s Either mode one or mode two operation may be selected. If n _min ≤n ^* <n _s The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, the signal period being T, and containing (1+j) rotation speeds, denoted 0=n _1- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein j is more than or equal to 1 and less than or equal to k, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set V. Rotational speed n _1- Corresponding to run DeltaT _1- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ And the total running time of all rotating speeds is T.

When n is _x =0: when the motor 12 is currently in a stop state, the controller 11 does not act, and the motor 12 maintains the current state; when the motor 12 is in the grid-connected operation state currently, the controller 11 controls the first switch K1 to be closed; when the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to be low, and then controls the second switch K2 to be turned off, or the controller 11 directly controls the second switch K2 to be turned off.

a、n _x ＝n _s and requires motor 12 to be n _s The operation is in a grid-connected operation state:

control when the motor 12 is currently in a stopped stateThe controller 11 controls the first switch K1 to be closed and controls the motor 12 to regulate the speed to n _s The motor 12 is operated in a grid-connected operation state;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s And controls the first switch K1 to be closed and the second switch K2 to be opened, so that the motor 12 operates in a grid-connected operation state;

b、n _x ＝n _s And requires motor 12 to be n _s Operating in off-line operating state or n _x ≠n _s

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the motor 12 to regulate the speed to n _x And controls the first switch K1 to be opened and the second switch K2 to be closed;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x Off-line operation;

(3)n ^* ∈[n _s ，n ₂ ]a variety of processing modes may be selected:

mode one, the motor 12 is finally operated in the grid-connected operation state, and the rotating speed is n ^* ＝n _s ＝n _v1 ：

The mode precondition is n _min ≤n _v1 ＝n _s ≤n ₂ I.e. n _s First-stage rotational speed n, which is a stepped rotational speed _v1 。

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* ＝n _s When the voltage of the motor 12 meets the grid-connected condition, the first switch K1 is controlled to be closed, and the second switch K2 is controlled to be opened, so that the motor 12 operates in a grid-connected operation state;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n ^* ＝n _s And controls the first switch K1 to be closed and the second switch K2 to be opened so that the motor 12 operates in a grid-connected operation state.

Mode two, the motor 12 is finally operated in the off-grid operation state, and the rotating speed is n ^* ＝n _vx ，n _vx For the sum n in set V ^* The nearest rotational speed:

when the motor 12 is currently in the grid-connected operation state, the first switch K1 is controlled to be opened, the second switch K2 is controlled to be closed, and the motor 12 is controlled to regulate the speed to n _vx The operation is in an off-line operation state;

Mode three, if n ^* ＝n _s Either mode one or mode two operation may be selected. If n _s <n ^* ≤n ₂ 0 is marked as a set A; n is n _v1 ，…，n _vm Is B and B epsilon n _min ，n ^* ]；n _ve ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, and e=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to 1 and less than or equal to k-m, and the rotating speed n _1- ，……，n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C. Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding toRun DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n ^* (n ^* ∈V)，n ₁₊ ，…，n _j+ Step rotation speed n _x ＞n _s ：

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _x ；

a、n _x ＝0

when the motor 12 is in the grid-connected operation state currently, the first switch K1 is controlled to be turned off;

d、n _x ≠n _s And n is _x ≠0

(4)n ^* >n ₂ Two processing modes can be selected if the rotation speed condition allowing grid connection is not met:

mode one, the motor 12 is finally operated in the off-grid operation state with a rotational speed n ^* ＝n _vx ，n _vx For the sum n in set V ^* The nearest rotational speed:

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _vx The operation is in an off-line operation state;

Mode two, record 0 as set A; n is n _v1 ，…，n _vm Is B and B epsilon n _min ，n ^* ]；n _ve ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, and e=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to 1 and less than or equal to k-m, and the rotating speed n _1- ，……，n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C. Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n ^* (n ^* ∈V)，n ₁₊ ，…，n _j+ One of (2), and n _x Are all greater than n _s When (1):

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _x Off-netAnd (5) running.

a、n _x ＝0

when the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to be low, and then the second switch K2 is turned off; or the controller 11 directly controls the second switch K2 to be turned off.

c、n _x ＝n _s And require n _s Operating in off-line mode

the current motor 12 is in a grid-connected running state, the controller 11 controls the second switch K2 to be closed, the first switch K1 to be opened, and controls the motor to regulate the speed to n _s Off-line operation;

the current motor 12 is currently in an off-grid operating state and is controlled by a controllerMotor speed regulation to n _s And (5) off-line operation.

d、n _x ≠n _s And n is _x ≠0

when the motor 12 is currently in the off-grid operation state, the controller 11 controls the motor 12 to regulate the speed to nx off-grid operation.

2. Referring to FIG. 12, when n _min ≤n _v1 <n _vg ＝n _s ≤n ₂ (△n ₁ ≥0，△n ₂ ≥0)

(1)n*∈[0，n _min ) There are several cases:

mode one, operating the motor 12 in a grid-connected operating condition at a speed n _s ＝n _vg ，n _vg Characterizing a certain level of rotation speed:

when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _s When the voltage of the motor 12 meets the grid-connected condition, the first switch K1 is controlled to be closed, and the second switch K2 is controlled to be opened, so that the motor 12 runs in grid-connected mode Running in a state;

Mode two, the motor 12 is operated in the off-grid operation state, and the rotating speed is n ^* ＝n _vx ，n _vx For the sum n in set V ^* The nearest rotational speed:

when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n _vx Off-line operation;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _vx Off-line operation;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _vx And (5) off-line operation.

Mode three, if n ^* ＝n _s Either mode one or mode two operation may be selected. If n _min ≤n ^* <n _s 0 is marked as a set A; n is n _v1 ，…，n _vm Is B and B epsilon n _min ，n ^* ]；n _ve ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, and e=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to 1 and less than or equal to k-m, and the rotating speed n _1- ，……，n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C.Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n _1- ，…，n _i- One of (2), and n _x All < n _s At this time, the following determination is made:

a、n _x ＝0

when the motor 12 is in the grid-connected operation state currently, the controller 11 controls the first switch K1 to be closed;

when the motor 12 is in the off-grid running state currently, the controller 11 controls the second switch K2 to be turned off after the speed is regulated to be low; or directly controls the second switch K2 to be opened.

b、n _x ≠0

a、n _x ＝n _s and requires motor 12 to be n _s Operating in a grid-connected operating state

When the motor 12 is in the stop state, the controller 11 controls the first switch K1 to be closed and controls the motor 12 to regulate the speed to n _s Then, the first switch K1 is controlled to be opened, and the second switch K2 is controlled to be closed, so that the motor 12 operates in a grid-connected operation state;

(3)n ^* ∈[n _s ，n ₂ ]according to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

mode one, the motor 12 is finally operated in the grid-connected operation state, and the rotating speed is n ^* ＝n _s ＝n _vg ：

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* ＝n _s Then, the first switch K1 is controlled to be opened, and the second switch K2 is controlled to be closed, so that the motor 12 operates in a grid-connected operation state;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n ^* ＝n _s And controls the first switch K1 to be closed and the second switch K2 to be opened, so that the motor 12 operates in a grid-connected operation state.

Mode two, the motor 12 is finally operated in the off-grid operation state,the rotation speed is n ^* ＝n _vx ，n _vx For the sum n in set V ^* The nearest rotational speed:

Mode three, if n ^* ＝n _s Either mode one or mode two operation may be selected. If n _s <n ^* ≤n ₂ 0 is marked as a set A; n is n _v1 ，…，n _vm Is B and B epsilon n _min ，n ^* ]；n _ve ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, and e=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to k-m, and the rotating speed n _1- ，……，n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C. Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n ^* (n ^* ∈V)，n ₁₊ ，…，n _j+ And a step rotation speed n _x Are all greater than n _s When (1):

a、n _x ＝0

when the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to be low, and then controls the second switch K2 to be turned off; or the controller 11 directly opens the second switch K2.

c、n _x ＝n _s And requires motor 12 to be n _s OperationIn the off-line running state

d、n _x ≠n _s And n is _x ≠0

when the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _vx The operation is in an off-line operation state;

Mode two, record 0 as set A; n is n _v1 ，…，n _vm Is B and B epsilon n _min ，n ^* ]；n _vn ，…，n _vk The set of k-m elements of (C) is C, and C.epsilon.n ^* ，n _max ]M is greater than or equal to 1, n=m+1. The controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, wherein the signal period is T and comprises (i+j) or (i+j+1) and the rotation speed n ^* And n is ^* E, V) rotational speeds, denoted 0.ltoreq.n _1- ＜n _2- ＜…＜n _i- ＜n ^* ＜n ₁₊ ＜n ₂₊ ＜…＜n _j+ ≤n _max Wherein i is more than or equal to 1 and less than or equal to m+1, j is more than or equal to 1 and less than or equal to k-m, and the rotating speed n _1- ，……，n _i- All are elements of the set A U B, and the rotating speed n ₁₊ ，……，n _j+ Are all elements of set C. Rotational speed n _i- Corresponding to run DeltaT _i- Time, rotation speed n _j+ Corresponding to run DeltaT _j+ Time, rotation speed n ^* Corresponding to run DeltaT _* And the total running time of all rotating speeds is T.

When the step rotation speed n _x Is n ^* (n ^* ∈V)，n ₁₊ ，…，n _j+ In (2) is greater than n _s ：

a、n _x ＝0

when the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to be low, and then controls the second switch K2 to be turned off; or directly opens the second switch K2.

When the motor 12 is currently in the grid-connected operation state, the current state is kept unchanged;

when the motor 12 is in the off-grid running state, the controller 11 controls the motor 12 to regulate the speed to n _s When the voltage of the motor 12 meets the grid-connected condition, the first switch K1 is controlled to be closed, and the second switch K2 is controlled to be opened, so that the motor 12 operates in a grid-connected operation state.

d、n _x ≠n _s And n is _x ≠0

The working frequency f of the single-phase alternating current power grid _g 50Hz, the pole pair number p of the motor 12 is 2, and the grid-connected rotating speed n _s ＝f _g * 60/p=1500 rpm, the lowest rotational speed n of the motor 12 _min =1200 rpm, maximum rotation n _max =4500 rpm, critical rotation speed n ₂ For 2000rpm, the control process is further described.

At a rotational speed of n _min <n _s <n ₂ (△n ₁ ＝300rpm>0，△n ₂ =500 rpm)

(1) If the target rotation speed n ^* E [0, 1200), there are several cases:

when the motor 12 is in the off-grid running state currently, the controller 11 performs speed regulation operation on the motor 12 until the rotation speed of the motor 12 reaches a low speed, and then the second switch K2 is controlled to be turned off; or the controller 11 directly controls the second switch K2 to be turned off (or controls the 4 switching tubes of the driving circuit 112 to be turned off).

(2)n ^* ∈[1200，1500]According to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

When the motor 12 is in the shutdown state, the controller 11 controls the second switch K2 to be closed, controls the first switch K1 to be opened, and controls the motor 12 to regulate the speed to n ^* ；

When the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n ^* Later running, so that the running state of the motor 12 is switched to the off-grid running state;

when the motor 12 is in the off-grid running state, the controller 11 adjusts the speed to n ^* And (5) performing later operation.

Mode two, the operation state of the control motor 12 is a grid-connected operation state, and the rotation speed is 1500 (n _s )：

When the motor 12 is in a shutdown state at present, the controller 11 controls the second switch K2 to be closed, controls the motor 12 to regulate the speed to 1500, then controls the second switch K2 to be opened and the first switch K1 to be closed, so that the running state of the motor 12 is switched to a grid-connected running state;

when the motor 12 is currently in the off-grid operation state, the controller 11 controls the motor 12 to regulate the speed to 1500, and controls the first switch K1 to be closed and the second switch K2 to be opened under the condition that the voltage of the motor 12 meets the grid-connected condition, so that the operation state of the motor 12 is switched to the grid-connected operation state.

Mode three, if n ^* =1200 or n ^* =1500, either mode one or mode two operation can be selected. If 1200 <n ^* <1500, the controller 11 adjusts the rotational speed of the motor 12 based on the stepped rotational speed signal. For example, the signal period is T and includes 4 rotational speeds of 0, 1200, 1500, 2000, and 4 rotational speeds of T ₁ 、t ₂ 、t ₃ And T4, the total running time of all rotating speeds is T.

a、n _x ＝0

When the motor 12 is in a stop state at present, the controller 11 does not act, and the current state of the motor 12 is maintained;

when the motor 12 is currently in a grid-connected operation state, direct power off is performed;

when the motor 12 is in the off-grid running state currently, the controller 11 is powered off to stop after the speed is regulated to be low, or directly turns off the second switch K2 to stop.

b. Rotational speed n _x =1500 (or 1200, 2000) and requires operation in off-line operating state

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n _x Switching the operation state of the motor 12 to off-grid operation;

c. Rotational speed n _x =1500 (or 1200, 2000) and requires operation in grid-tie operation

When the motor 12 is in a shutdown state currently, the controller 11 controls the second switch K2 to be closed, controls the motor 12 to regulate the speed to 1500, and controls the first switch K1 to be closed and the second switch K2 to be opened under the condition that the voltage of the motor 12 meets the grid-connected condition, so that the running state of the motor 12 is switched to the grid-connected running state;

when the motor 12 is currently in the off-grid operation state, the controller 11 controls the motor 12 to regulate the speed to 1500, and controls the first switch K1 to be closed and the second switch K2 to be opened, so that the operation state of the motor 12 is switched to the grid-connected operation state.

(3)n ^* ∈(1500，2000]According to the rotation speed condition allowing grid connection, a plurality of processing modes can be selected:

mode one, the operation state of the control motor 12 is the off-grid operation state, and the rotation speed is set to n ^* ：

When the motor 12 is in the stop state, the controller 11 controls the motor 12 to regulate the speed to n ^* Operating;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n ^* Then running;

Mode two, the running state of the control motor 12 is a grid-connected running state, and the rotating speed is set to 1500:

when the motor 12 is in a shutdown state currently, the controller 11 controls the second switch K2 to be closed and the first switch K1 to be opened, controls the motor 12 to regulate the speed to 1500, and then the controller 11 controls the first switch K1 to be closed and the second switch K2 to be opened, so that the running state of the motor 12 is switched to a grid-connected running state;

Mode three, if n ^* =1500 or n ^* =2000, either mode one or mode two operation may be selected. If 1500<n ^* <2000, the controller 11 controls the motor 12 to regulate speed based on the stepped rotation speed signal, the signal period is T, the total rotation speed is 4, the rotation speeds are respectively 0, 1500, 2000 and 3000, and the running time of the 4 rotation speeds is respectively T ₁ 、t ₂ 、t ₃ 、t ₄ And the total running time of all rotating speeds is T.

a. Rotational speed value n _x ＝0，

Maintaining the current state when the motor 12 is currently in the shutdown state;

b. Rotational speed n _x =1500 and requires operation in off-line operation state or n _x When the value of =2000,3000,

when the motor 12 is in the stop state, the controller 11 controls the motor 12 to regulate the speed to n _x Off-netOperating;

when the motor 12 is currently in the grid-connected operation state, the off-grid command is executed, and the controller 11 controls the motor 12 to regulate the speed to n _x Off-line operation;

c、n _x =1500 and requires operation in grid-connected operating state

When the motor 12 is in a shutdown state at present, the controller 11 controls the motor 12 to regulate the speed to 1500, and after the controller 11 further controls the terminal voltage of the motor 12 to reach a grid-connected condition, the motor 12 is operated in a grid-connected operation state;

when the motor 12 is currently in the grid-connected operation state, keeping the current state unchanged;

when the motor 12 is in the off-grid running state currently, the controller 11 controls the motor 12 to regulate the speed to 1500, and after the controller 11 further controls the terminal voltage of the motor 12 to reach the grid-connected condition, the motor 12 is made to run in the grid-connected running state.

(4)n ^* >n ₂ The rotation speed condition allowing the grid connection is not met, the rotation speed set by the controller 11 is set as n ^* The motor 12 eventually rotates at a speed n ^* Operating in off-line mode

When the motor 12 is in the stop state, the controller 11 controls the second switch K2 to be closed and controls the motor 12 to regulate the speed to n ^* The operation is carried out, and then the second switch K2 is controlled to be opened, and the first switch K1 is controlled to be closed;

when the motor 12 is currently in the grid-connected operation state, the controller 11 controls the first switch K1 to be opened and the second switch K2 to be closed, and controls the motor 12 to regulate the speed to n ^* Operating;

In any of the above embodiments, the motor 12 is switched to the off-grid operation state, and may be realized by controlling the switching states of the 4 switching tubes of the driving circuit 112, in addition to the closing of the second switch K2.

Fig. 13 is a flowchart of a control method of a motor according to an exemplary embodiment of the present invention, the control method includes the following steps:

step 301, in response to a control signal of the motor, determining a target rotational speed matching the type of the control signal.

And step 302, switching the running state of the motor according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to achieve the control target of the control signal.

The operation states comprise a grid-connected operation state and an off-grid operation state; the motor in the grid-connected operation state is directly powered by a single-phase alternating current power grid; and the motor in the off-grid running state is powered by the output of the controller.

Optionally, in response to a control signal of the motor, determining a target rotational speed that matches a type of the control signal includes:

and determining a target rotating speed matched with the type of the control signal according to the corresponding relation between the signal frequency and the rotating speed.

Optionally, the switching the operation state of the motor according to the target rotation speed and the operating frequency includes at least one of:

determining a rotation speed condition allowing grid connection according to the working frequency;

when the target rotating speed accords with the rotating speed condition, controlling the running state of the motor to be switched into a grid-connected running state or a grid-off running state;

and when the target rotating speed does not meet the rotating speed condition, controlling the running state of the motor to be switched into the off-grid running state.

Optionally, controlling the operation state of the motor to be switched to a grid-connected operation state includes:

and adjusting the actual rotating speed of the motor to meet the rotating speed condition, and controlling the running state of the motor to be switched into a grid-connected running state.

Optionally, in the case that the motor is operated in a stepless speed regulation mode, determining a rotation speed condition allowing grid connection according to the operating frequency includes:

calculating the grid-connected rotating speed allowing grid connection according to the working frequency;

when the grid-connected rotating speed, the critical rotating speed of the motor and the lowest rotating speed of the motor are identical, the rotating speed condition comprises that the target rotating speed is equal to the grid-connected rotating speed;

when the grid-connected rotating speed is equal to the lowest rotating speed and smaller than the critical rotating speed, the rotating speed condition comprises that the target rotating speed falls into a first rotating speed range, the upper limit of the first rotating speed range is the critical rotating speed, and the lower limit of the first rotating speed range is the grid-connected rotating speed;

when the grid-connected rotating speed is greater than the lowest rotating speed and smaller than the critical rotating speed, the rotating speed condition comprises that the target rotating speed falls into a second rotating speed range, the upper limit of the second rotating speed range is the critical rotating speed, and the lower limit of the second rotating speed range is the lowest rotating speed.

Optionally, in the case that the motor is operated in a step-wise speed regulation mode, determining a rotation speed condition allowing grid connection according to the operating frequency includes:

When the grid-connected rotating speed is an element in the step-by-step speed regulation set of the motor, and the grid-connected rotating speed is greater than or equal to the lowest rotating speed of the motor and less than or equal to the critical rotating speed, the rotating speed condition comprises that the target rotating speed falls into a second rotating speed range, the upper limit of the second rotating speed range is the critical rotating speed, and the lower limit of the second rotating speed range is the lowest rotating speed.

The control method of the embodiment of the invention can be realized by the control circuit provided by any one of the embodiments.

Fig. 14 is a schematic block diagram of a control device for an electric motor according to an exemplary embodiment of the present invention, where the control device includes:

a determining module 41 that determines a target rotational speed of the motor corresponding to a control signal of the motor in response to the control signal;

the control module 42 switches the running state of the motor according to the target rotating speed and the working frequency of the single-phase alternating current power grid so as to achieve the control target of the control signal; the operation states comprise a grid-connected operation state and an off-grid operation state; the motor in the grid-connected operation state is directly powered by the single-phase alternating current power grid; and the motor in the off-grid running state is powered by the output of the controller.

Optionally, the determining module 41 is specifically configured to:

Optionally, the control module 42 is specifically configured to:

Optionally, when the operation state of the motor is controlled to be switched to the grid-connected operation state, the control module 42 is specifically configured to:

Alternatively, in the case of operation of the motor in a stepless speed regulation mode, the control module 42 is specifically configured to:

Alternatively, in the case where the motor is operating in a step-wise governor mode, the control module 42 is specifically configured to:

For the device embodiments, reference is made to the description of the method embodiments for the relevant points, since they essentially correspond to the method embodiments. The apparatus embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purposes of the present invention.

Fig. 15 is a schematic structural diagram of an electronic device according to the present embodiment. The electronic device comprises a memory, a processor and a computer program stored on the memory and used for running on the processor, wherein the processor realizes the control method of the motor provided by any embodiment when executing the program. The electronic device 500 shown in fig. 15 is merely an example, and should not be construed as limiting the functionality and scope of use of embodiments of the present invention.

Referring to fig. 15, the electronic device 500 may be embodied in the form of a general purpose computing device, which may be a server device, for example. The components of electronic device 500 may include, but are not limited to: the at least one processor 501, the at least one memory 502, and a bus 503 that connects the various system components, including the memory 502 and the processor 501.

The bus 503 includes a data bus, an address bus, and a control bus.

Memory 502 may include volatile memory such as Random Access Memory (RAM) 521 and/or cache memory 522, and may further include Read Only Memory (ROM) 523.

Memory 502 may also include a program/utility 525 having a set (at least one) of program modules 524, such program modules 524 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of which may include an implementation of a network environment.

The processor 501 executes various functional applications and data processing, such as a control method of the motor of the embodiment of the present invention, by running a computer program stored in the memory 502.

The electronic device 500 may also communicate with one or more external devices 504 (e.g., keyboard, pointing device, etc.). Such communication may occur through an input/output (I/O) interface 505. Also, model-generated device 500 may also communicate with one or more networks such as a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the internet via network adapter 506. As shown, the network adapter 506 communicates with other modules of the model-generating device 500 via the bus 503. It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in connection with the model-generating device 500, including, but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, data backup storage systems, and the like.

It should be noted that although several units/modules or sub-units/modules of an electronic device are mentioned in the above detailed description, such a division is merely exemplary and not mandatory. Indeed, the features and functionality of two or more units/modules described above may be embodied in one unit/module in accordance with embodiments of the present invention. Conversely, the features and functions of one unit/module described above may be further divided into ones that are embodied by a plurality of units/modules.

The present embodiment also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the method for controlling a motor provided by any of the above embodiments.

More specifically, among others, readable storage media may be employed including, but not limited to: portable disk, hard disk, random access memory, read only memory, erasable programmable read only memory, optical storage device, magnetic storage device, or any suitable combination of the foregoing.

In a possible embodiment, the invention may also be implemented in the form of a program product comprising program code for causing a terminal device to carry out the control method of the electric motor as provided by any of the above-mentioned embodiments, when said program product is run on the terminal device.

Wherein the program code for carrying out the invention may be written in any combination of one or more programming languages, which program code may execute entirely on the user device, partly on the user device, as a stand-alone software package, partly on the user device and partly on the remote device or entirely on the remote device.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.

Claims

1. A control circuit for an electric machine, the control circuit comprising: the controller, the first switch and the second switch;

the motor is connected with the controller through the second switch;

2. The control circuit of a motor of claim 1, wherein the controller comprises: the device comprises a voltage conversion circuit, a driving circuit and a signal processing module; the voltage conversion circuit is used for converting alternating current of the single-phase alternating current power grid into direct current; the driving circuit is used for converting the direct current into alternating current for the motor to operate; the signal processing module is used for determining the target rotating speed according to the control signal and controlling the switching states of the first switch and the second switch according to the target rotating speed and the working frequency;

alternatively, the controller includes: a driving circuit and a signal processing module; the driving circuit is used for converting direct current provided by the direct current power supply into alternating current for the motor to operate; the signal processing module is used for determining the target rotating speed according to the control signal and controlling the switching states of the first switch and the second switch according to the target rotating speed and the working frequency.

3. The control circuit of a motor of claim 2, wherein the control circuit further comprises: a voltage acquisition module;

the voltage acquisition module is connected with the single-phase alternating current power grid;

The voltage acquisition module is used for acquiring a voltage signal of the single-phase alternating current power grid and sending the voltage signal to the controller;

the controller is also used for controlling the switching state of a switching tube contained in the driving circuit according to the voltage signal, the control signal and the operation data of the motor.

4. A control circuit of an electric machine according to claim 2 or 3, characterized in that the second switch is one of the following: the solid-state relay, the electromagnetic relay and the switching tube contained in the driving circuit.

5. A control method of an electric motor, characterized by comprising:

6. The method of controlling a motor according to claim 5, wherein determining a target rotational speed that matches a type of the control signal in response to the control signal of the motor includes:

7. The control method of the motor according to claim 5, characterized in that switching the operation state of the motor according to the target rotation speed and the operating frequency includes at least one of:

8. The method of controlling a motor according to claim 7, wherein controlling the operation state of the motor to be switched to the grid-connected operation state includes:

9. The method according to claim 7, wherein determining a rotation speed condition allowing grid connection according to the operation frequency in a case where the motor is operated in a stepless speed regulation mode, comprises:

10. The method according to claim 7, wherein determining a rotation speed condition allowing grid connection according to the operation frequency in a case where the motor is operated in a step-wise governor mode, comprises:

11. A control device of an electric motor, characterized in that the control device of an electric motor comprises:

12. An electronic device comprising a memory, a processor and a computer program stored on the memory for execution on the processor, characterized in that the processor implements the method of controlling the motor according to any one of claims 5 to 10 when executing the computer program.

13. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the method of controlling an electric machine according to any one of claims 5 to 10.