CN105696250B - A kind of energy-saving control method and washing machine of washing machine - Google Patents

Abstract

The invention discloses an energy-saving control method of a washing machine and the washing machine. When the washing machine is controlled to finish rinsing and dehydration and/or spin-drying and dehydration operations, the induced current generated by the motor in the washing machine due to inertial operation is recovered and stored. When the power meets the power supply requirements of the low-voltage load in the washing machine, the low-voltage load is supplied with power. The invention recovers and stores the energy of the reverse electromotive force generated by the motor due to inertial operation when the washing machine completes the rinsing and dehydration and spin-drying dehydration operations, and when the stored electricity reaches the power supply requirements required by the control circuit in the washing machine, the energy is reversed. It replaces the main power supply circuit to supply power to the control circuit, thus effectively solving the problem of energy waste caused by washing machines after rinsing and dehydration and drying and dehydration in the past, effectively reducing the consumption of external energy, realizing the maximum utilization of energy, and then significantly improving The energy efficiency of the washing machine.

Description

Energy-saving control method of washing machine and washing machine

technical field

The invention belongs to the technical field of washing machines, and in particular relates to an energy-saving control technology for recycling the energy generated by the washing machine during operation and a washing machine designed based on the energy-saving control technology.

Background technique

Under the grim situation that the global energy demand continues to grow and the actual supply continues to decline, the country's energy efficiency standards for the home appliance industry have been continuously improved, and the requirements for energy conservation have been greatly increased. In the existing DC frequency conversion washing machine, the motor used inside is a DC brushless motor, and the body stator of this DC brushless motor is a three-phase winding connected in a star shape. In order to realize the driving control of the DC brushless motor, a power supply system and a control system are usually set in the DC frequency conversion washing machine. Among them, the power supply system is used to rectify, filter, and stabilize the externally connected AC mains into the DC power supply required by each load in the control system to meet the power demand of each load. The control system is mainly composed of a power circuit and a control circuit, responsible for running the washing program, and driving the DC brushless motor to run in an orderly manner according to the program process to complete the entire washing process. Among them, the control circuit is composed of a single-chip microcomputer with high-speed computing capability, a drive circuit and other auxiliary circuits. The power circuit is a three-phase inverter composed of six high-power IGBT modules. Under the action of the control signal output by the control circuit, the three-phase inverter inverts the DC bus voltage output by the power circuit into a three-phase AC , to drive the DC brushless motor to run and output power.

The traditional washing machine will perform dehydration treatment at the end of rinsing clothes and when the washing is finally completed, and a complete washing process needs to perform dehydration treatment at least three times. When the DC brushless motor is running at high speed, a reverse electromotive force will be generated in the coil. After the dehydration is completed and the control of the motor is turned off, due to the resistance, the speed of the motor will become smaller and smaller, and the reverse electromotive force will also become smaller and smaller. Finally, the kinetic energy is converted into electrical energy, and the electrical energy is converted into heat energy and consumed. It can be seen that the DC brushless motor in the existing washing machine is only used as a motor, and the energy of the reverse electromotive force generated by it is not fully utilized, resulting in unnecessary waste of energy.

Contents of the invention

In order to reduce the power consumption of the washing machine, the present invention proposes an energy-saving control method for the washing machine. The design purpose of saving energy is achieved by recovering, storing and utilizing the reverse electromotive force energy generated by the motor in the washing machine.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions to achieve:

An energy-saving control method for a washing machine. When the washing machine is controlled to finish rinsing and dehydration and/or spin-drying and dehydration operations, the induced current generated by the motor in the washing machine due to inertial operation is recovered and stored, and the stored power meets the low voltage in the washing machine. When the power supply required by the load is required, supply power to the low-voltage load.

In order to effectively recover and store the induced current generated by the motor, and maintain the aesthetics of the overall appearance of the washing machine, it is preferable to build an energy storage element in the washing machine to rectify the induced current generated by the motor during the inertial operation. , to charge and store energy for the energy storage element; detect the total voltage of the energy storage element in real time, and when the total voltage is lower than the power supply requirement, cut off the discharge circuit of the energy storage element and switch back to the main power supply powered by.

Preferably, the energy storage element is a battery pack. When charging the battery pack, first detect the size of the back electromotive force generated by the motor, and then select a battery pack with a corresponding voltage level for charging according to the size of the back electromotive force Energy storage to improve charging efficiency.

In order to ensure the safety of the operation of the energy storage element and the control circuit, the temperature and the charge and discharge current of the energy storage element are detected in real time, and the energy storage element is cut off when the temperature of the energy storage element is too high or the charge and discharge current is too large The charging and discharging circuit to avoid damage to the energy storage element.

Based on the above energy-saving control method, the present invention also proposes a washing machine, which is provided with a main power circuit, a control circuit, a motor, and a power circuit for driving the motor; Induced current is generated due to inertial operation, and the induced current is rectified into a DC current by a rectifier circuit, and then transmitted to an energy storage element for charging and energy storage; the energy stored in the energy storage element meets the power supply requirements of the control circuit , the output power supplies power for the control circuit.

In order to control the charging and discharging sequence of the energy storage element in an orderly manner, a controller and a voltage detection circuit are arranged in the control circuit, and the voltage detection circuit detects the electric quantity stored in the energy storage element and feeds it back to In the controller, the controller performs gating switching between the power supply loop where the control circuit is connected to the main power supply circuit and the power supply loop where the control circuit is connected to the energy storage element according to the detected electric quantity.

Preferably, the energy storage element is a battery pack. In order to improve charging efficiency, the voltage detection circuit detects the total voltage of the battery pack and the voltage of a single battery, and detects The back electromotive force generated by the motor is detected; the controller gates the battery pack of the corresponding voltage level to charge according to the detected back electromotive force.

Further, the control circuit is also provided with a current detection circuit and a temperature detection circuit, which respectively detect the charging and discharging current of the battery pack and the temperature of the battery pack, and feed back to the controller; the controller detects When the temperature of the battery pack is too high or the charging and discharging current is too large, the charging and discharging circuit of the battery pack is cut off to ensure the safe operation of the battery pack.

In order to minimize the modification of the existing electronic components in the control circuit, the present invention preferably adds a power management chip to the control circuit, and the detection signals generated by the voltage detection circuit, current detection circuit and temperature detection circuit are first After being transmitted to the power management chip and processed into a digital signal, it is then transmitted to the controller through the bus.

Further, the motor is a DC brushless motor; a three-phase inverter circuit connected by six power tubes is provided in the power circuit, and a freewheeling diode is connected in reverse parallel to each power tube , six freewheeling diodes constitute the rectification circuit, and rectify and output the induced current output by the motor.

Compared with the prior art, the advantages and positive effects of the present invention are: the present invention recovers and stores the energy of the reverse electromotive force generated by the motor due to inertial operation when the washing machine completes the rinsing and dehydration and spin-drying dehydration operations, When the stored electricity reaches the power supply requirements required by the control circuit in the washing machine, it will in turn replace the main power supply circuit to supply power to the control circuit, thereby effectively solving the problem of energy waste caused by washing machines after rinsing and dehydration and drying and dehydration in the past. The consumption of external energy realizes the maximum utilization of energy, and then significantly improves the energy efficiency value of the washing machine.

Other features and advantages of the present invention will become more apparent after reading the detailed description of the embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a block diagram of the overall structure of the circuit of an embodiment of the washing machine proposed by the present invention;

Fig. 2 is a partial circuit block diagram of an embodiment of a control circuit and a power circuit in Fig. 1;

Fig. 3 is a circuit principle block diagram of an embodiment of charge and discharge control of the energy storage element in Fig. 1;

FIG. 4 is a specific circuit schematic diagram of FIG. 3 .

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

In this embodiment, the washing machine energy-saving control method of the present invention is specifically described by taking a DC frequency conversion washing machine equipped with a DC brushless motor as an example.

In order to effectively improve the energy efficiency value of the DC inverter washing machine in this embodiment, after the washing machine completes the rinsing and dehydration and/or spin-drying dehydration functions and closes the control of its internal motor, the motor maintains high-speed operation due to inertia during this period. The energy of the reverse electromotive force is stored, that is, the motor is reversed into a generator to output energy during this period, and by effectively recovering this part of energy, and when the stored energy can meet the power supply requirements required by the low-voltage load in the washing machine , which in turn replaces the original main power supply circuit in the washing machine to supply power to the low-voltage load in the washing machine, thereby reducing the external energy consumption of the washing machine and achieving the design purpose of energy saving.

In this embodiment, the low-voltage loads may specifically refer to the electrical loads arranged in the control circuit on the internal system board of the washing machine, and the power supply voltage thereof is generally required to be below 15V. As for the power circuit used to drive the motor in the washing machine, since the required DC bus voltage has a relatively high amplitude, often above 300V, it is still necessary to use the power supply method of the existing main power supply circuit for its power supply.

In this embodiment, in order to effectively recover and utilize the induced current generated by the motor running under the action of inertia, an energy storage element is added inside the washing machine, as shown in FIG. 1 . The energy storage element may be a storage battery, or a battery pack or a large capacitor formed by connecting multiple lithium batteries in series. Since the stator in the DC brushless motor is a three-phase winding with a star connection, the current induced by the three-phase winding is an alternating current during the inertial operation of the motor. Therefore, it is necessary to rectify the induced current output by the motor into DC. In order to meet the charging requirements of the energy storage element. For this reason, in this embodiment, a rectifier circuit is provided on the internal circuit board of the washing machine, connected to the DC brushless motor, receiving the alternating current induced and output by the DC brushless motor, and rectifying it into a DC current, and outputting it to The energy storage element charges and stores energy for the energy storage element.

In order to simplify the circuit design, in this embodiment, the power circuit used to drive the motor in the washing machine is preferably also used as a rectifier circuit to realize the rectification and transformation of the induced current. Specifically, in the existing washing machine circuit, its power circuit is usually a three-phase inverter connected by six high-power IGBT tubes V1-V6 or MOSFET tubes, as shown in Figure 2, used to The DC bus voltage output by the main power supply circuit is inverted to generate a three-phase AC power supply with the required frequency, which drives the DC brushless motor to run at the required speed and output kinetic energy. In this embodiment, a freewheeling diode D1-D6 is respectively connected in reverse parallel to each power transistor V1-V6. Taking the IGBT transistor V1-V6 shown in FIG. 2 as an example for illustration, each IGBT transistor V1-V6 can be A freewheeling diode D1-D6 is connected between the collector and the emitter, and the cathode of the freewheeling diode D1-D6 is connected to the collector of the IGBT tube V1-V6, and the anode of the freewheeling diode D1-D6 is connected to the IGBT tube V1-V6 the emitter. As a result, the six freewheeling diodes D1-D6 are connected to form a three-phase full-bridge rectifier circuit, which is connected to the three-phase winding of the DC brushless motor. When the motor is used as a generator to output the induced current, after the induced current is rectified and transformed, Output direct current to the energy storage element to charge and store energy for the energy storage element.

In order to make reasonable use of the electric energy stored in the energy storage element, in this embodiment, a power management circuit is further provided on the internal circuit board of the washing machine, and as shown in Figure 1 and Figure 3, the energy storage element is connected to detect the energy storage The electric energy stored in the energy element, and when the stored electric energy is sufficient to meet the power demand of the control circuit, cut off the power supply from the main power supply circuit to the control circuit, and transfer the energy storage element to supply power for each electric load in the control circuit, so as to reduce the The consumption of external energy achieves the design purpose of energy saving.

In this embodiment, the main power supply circuit may be composed of main parts such as a bridge rectifier, a filter circuit, and a DC converter, as shown in FIG. 1 . Among them, the bridge rectifier is used to receive the external AC mains, rectify the AC mains into a DC power supply, and then output it to the filter circuit for filtering processing, and then generate a stable high-voltage DC power supply, such as +310V DC power supply, and output it to The three-phase inverter in the power circuit provides the DC bus voltage required by the three-phase inverter. The DC converter is used to step down the DC bus voltage output by the filter circuit to generate a low-voltage DC power supply VDD, such as a +15V low-voltage DC power supply, which is output to the DC-DC converter and generated by the DC-DC converter in the control circuit. The DC power supply VCC required by different electrical loads, such as +5V or +3.3V DC power supply.

In order to ensure the effective power supply of the energy storage element to the control circuit, the power management circuit is designed to switch to the energy storage element to supply power to the control circuit after detecting that the power stored in the energy storage element reaches VDD, such as +15V. Specifically, the electrical energy output by the energy storage element can be transmitted to the input end of the DC-DC converter, and the DC-DC converter can be used to convert the electrical energy output by the energy storage element into the DC power required by each electrical load in the control circuit VCC, supplies power to the control circuit.

In the power management circuit of this embodiment, a voltage detection circuit, a current detection circuit, and a temperature detection circuit are provided, which are used to detect the voltage, charge and discharge current, and operating temperature of the energy storage element respectively as shown in FIG. 3 , and according to The detection results generate corresponding detection signals and output them to the power management chip. After the power management chip processes the received detection signals into digital signals, they are transmitted to the controller in the control circuit through a communication circuit (such as a bus), such as a high-speed The single-chip microcomputer with data processing capability generates corresponding control signals through the controller to accurately gate and switch between the power supply circuit where the control circuit is connected to the main power supply circuit and the power supply circuit where the control circuit is connected to the energy storage element. At the same time, the controller can accurately judge whether the current working state of the energy storage element is normal according to the received charging and discharging current and temperature changes. When an abnormality occurs, the controller can cut off the charging of the energy storage element in time. circuit and discharge circuit to ensure the safety of the energy storage components and the circuit of the entire system.

In this embodiment, a battery pack is used as the energy storage element as an example for illustration. The voltage detection circuit of this embodiment respectively detects the total voltage of the battery pack and the voltage of a single battery, and when the washing machine finishes rinsing and dehydration and/or spin-drying and dehydration operations, the controller controls the switch element K8 to close, and uses the voltage detection circuit to The back electromotive force generated by the motor is detected, and one or more of the switching elements K2-K6 are selected to be turned on according to the detected back electromotive force, so as to gate the battery pack of the corresponding voltage level for charging, so as to improve the charging efficiency. The controller determines which power supply method to choose according to the detected total voltage of the battery pack. When it is detected that the total voltage of the battery pack exceeds the set threshold, for example, when it exceeds VDD, the control switch element K7 is closed, and the main power supply circuit is cut off at the same time to control The power supply of the circuit is then transferred to the battery pack to supply power for the control circuit to save external energy.

As an optimal circuit construction method of the voltage detection circuit, in this embodiment, a multi-channel resistor voltage divider network is provided in the voltage detection circuit. Taking N batteries connected in series in the battery pack BAT as an example, then N+1 resistance voltage divider networks should be set in the voltage detection circuit, where N is a positive integer greater than 1. As shown in Figure 4, taking N=5 as an example for illustration, in order to realize the detection of the voltage of a single battery and the detection of the reverse electromotive force generated by the motor, this embodiment connects the positive electrode of each battery and the ground one by one Correspondingly connect one resistor voltage divider network, for example, a five-way resistor voltage divider network composed of resistors R32-R36, R39-R43, and output five sampling voltages VS1- VS5 is respectively transmitted to the five ADC pins AD2-AD6 of the power management chip U1, which is converted into a digital signal by the analog-to-digital converter inside the power management chip U1, and thus the voltage of each single battery and the entire battery can be calculated The total voltage of the group. The power management chip U1 transmits the calculated voltage value to the controller MCU through the communication circuit for subsequent charging control. Connect the resistors R48 and R49 to form a sixth resistor voltage divider network, connect one end of the sixth resistor voltage divider network to ground, and connect the other end to the DC side of the power circuit IPM through the switch element K8, and connect the voltage divider node to the power supply Another ADC pin AD1 of the management chip U1 is used for sampling and detecting the back electromotive force VF generated by the motor.

In the battery pack BAT, the positive electrode of each battery is respectively connected to the DC side of the power circuit IPM through a branch circuit formed by routing current limiting resistors R22-R36 and switching elements K2-K6 in series, and the controller MCU detects The size of the reverse electromotive force VF is controlled to control one or more of the switching elements K2-K6 to be turned on, and then the battery pack with a voltage level corresponding to the reverse electromotive force VF is selected for charging, so as to improve the charging efficiency.

In the temperature detection circuit of this embodiment, a voltage dividing circuit formed by connecting a thermistor RZ and a voltage dividing resistor R37 is provided. As shown in FIG. 4, it is connected between the DC power supply VCC and the ground. Connect to the ADC pin AD0 of the power management chip U1. The thermistor RZ is built into the battery pack BAT, senses the temperature change of the battery pack BAT, and changes its own resistance according to the temperature change of the battery pack BAT, thereby changing the voltage value at the voltage dividing node. The power management chip U1 converts the temperature value of the battery pack BAT according to the received voltage value, and transmits it to the controller MCU. The controller MCU judges whether the working temperature of the battery pack BAT is normal according to the received temperature value. If it exceeds the set safe temperature range, the output control signal controls the switching element K7 to turn off, cutting off the discharge circuit of the battery pack BAT, that is, breaking Open the connection between the battery pack BAT and the DC-DC converter U3, and at the same time control the switching element K9 connected between the DC converter U2 and the DC-DC converter U3 to close, and then the main power supply circuit supplies power to the control circuit. When the controller MCU detects that the temperature of the battery pack BAT is abnormal, in order to ensure the charging safety of the battery pack BAT, at the same time output a control signal to control the switching elements K2-K6 connected between the power circuit IPM and the battery pack BAT to be disconnected to cut off The charging circuit of the battery pack BAT.

In order to detect the charging and discharging current of the battery pack BAT, in this embodiment, the sampling resistor RS2 is connected in series in the battery pack BAT, specifically, it may be connected between the negative electrode of the battery pack BAT and the ground. One end of the sampling resistor RS2 connected to the battery pack BAT is connected to the reference power supply VREF through the first voltage dividing resistor R31 and the second voltage dividing resistor R38 connected in series, and the middle node of the first voltage dividing resistor R31 and the second voltage dividing resistor R38 is connected to The non-inverting input terminal + of the operational amplifier U4, the inverting input terminal - of the operational amplifier U4 is connected to the other end of the sampling resistor RS2 through the current limiting resistor R30, and connected to the output of the operational amplifier U4 through the feedback resistor R44 end. The current flowing through the sampling resistor RS2 is sampled through the operational amplifier U4, and output to the power management chip U1 through the resistor R45, such as the ADC pin AD7 of the power management chip U1, and then converted into a digital signal and sent to the controller MCU to realize battery monitoring. Real-time monitoring of group BAT charge and discharge current.

In order to realize over-current protection, a comparator U5 is also provided in the current detection circuit in this embodiment, as shown in FIG. 4 . Connect the inverting input terminal - of the comparator U5 to one end of the sampling resistor RS2 connected to the battery pack BAT, and connect the non-inverting input terminal + of the comparator U5 to a reference voltage, and the reference voltage can be obtained by using a voltage dividing resistor R28, R29 forms a voltage divider for the DC power supply VCC. According to the set current threshold, the resistance values of the voltage dividing resistors R28 and R29 are adjusted so that the reference voltage formed by the voltage division just corresponds to the current threshold. When the charging and discharging current of the battery pack BAT is normal, the voltage drop across the sampling resistor RS2 is less than the reference voltage, so the comparator U5 outputs a high-level signal and transmits it to the I/O port of the power management chip U1. When the charging and discharging current of the battery pack BAT increases and exceeds the current threshold, the voltage drop across the sampling resistor RS2 is greater than the reference voltage, so the comparator U5 outputs a low-level overcurrent protection signal Io, which is transmitted to the The I/O port of the power management chip U1. When the power management chip U1 detects that its I/O port is set to a low level, it outputs an alarm signal to the controller MCU, and cuts off the charging and discharging circuit of the battery pack BAT through the controller MCU, that is, controls the switch elements K2-K7 to turn off. On, overcurrent protection is performed on the battery pack BAT.

The specific working process of the washing machine of this embodiment will be described in detail below with reference to FIG. 4 .

When the washing machine is in the state of washing, rinsing or spin-drying, the DC brushless motor operates as a motor. At this time, the controller MCU first controls the switching element K1 connected between the power circuit IPM and the main power circuit to close, and the 220V AC mains is rectified and filtered by the bridge rectifier BD1 and the filter circuits E1 and C1 to convert the AC mains into DC The bus voltage is transmitted to the DC side of the power circuit IPM through the switch element K1. During this period, the switching elements K2-K6 and K8 are all turned off, and the switching elements K7 and K9 select one of them to be closed according to the remaining power of the battery pack BAT to supply power for the DC-DC converter U3 to generate the DC required by the control circuit. powered by.

The controller MCU outputs PWM modulation signals to control the operation of the three-phase inverter in the power circuit IPM according to the current operating state of the washing machine (that is, controls the on-off sequence of six high-power IGBT tubes V1-V6), and inverts the DC bus voltage into three-phase alternating current to power the motor. When a certain two phases of the stator winding inside the motor are energized, the current interacts with the magnetic field generated by the magnetic poles of the permanent magnets of the rotor to generate torque, which drives the rotor to rotate, and then the position sensor U6 converts the position of the rotor magnets into electric current. The signal is fed back to the controller MCU. The controller MCU determines the rotor position according to the detected electrical signal, and then controls the on-off sequence of the IGBT tubes V1-V6 according to the rotor position, so that the windings of the stator are conducted in a certain order, and the stator phase current changes with the rotor position And change phases in a certain order. Since the conduction sequence of the IGBT tubes V1-V6 is synchronized with the rotor angle, it plays the role of commutation of the mechanical commutator, drives the DC brushless motor to run, and outputs kinetic energy.

When the washing machine finishes rinsing and dehydration or drying and dehydration, when the DC brushless motor is in the state of inertial operation, in order to effectively use the reverse electromotive force generated by the DC brushless motor, the controller MCU first turns on the switch element K1 and switches to the charging circuit. Close the switching element K8 to detect the magnitude of the back electromotive force generated by the motor, and then select one or more of the switching elements K2-K6 to close according to the detected back electromotive force VF, and then pass different current limiting resistors R22-R26 to the corresponding Voltage level for battery pack charging. At the same time, through the power management chip U1, the total voltage of the battery pack BAT and the voltage of the unit cells are detected in real time, and the charging current and operating temperature of the battery pack BAT are detected in real time to avoid excessive charging current and high temperature. temperature rise.

After the charging is completed, the switching elements K2-K6 are turned off, the charging circuit of the battery pack BAT is cut off, and the power supply mode to be adopted is determined according to the detected total voltage of the battery pack BAT. If the power of the battery pack BAT meets the power supply requirements, for example, VDD, then the switch element K7 is closed, and the voltage of the battery pack BAT is converted into the DC power supply VCC required by the control circuit through the DC-DC converter U3, which is used for each control circuit. power supply to the load. In the process of using the battery pack BAT for power supply, the voltage, current and temperature of the battery pack BAT are detected in real time. Once the voltage of the battery pack BAT is insufficient, the current is too large or the temperature is too high, the controller MCU will promptly control the switch element K7 Disconnect, cut off the discharge circuit of the battery pack BAT, and close the switch element K9 at the same time, and transfer the main power supply circuit to continue to supply power for the control circuit.

In this embodiment, the switching elements K1-K9 may be designed with relays or other controllable switching elements, which is not specifically limited in this embodiment.

Applying the energy-saving control technology of this embodiment to the current design of the current DC inverter washing machine can not only control the forward electric energy rotation energy of the brushless DC motor, but also make the brushless DC The energy element is charged and stored, and by effectively utilizing the reverse electromotive force generated by the DC brushless motor due to the inertial operation, energy is saved and the energy efficiency value of the DC inverter washing machine is improved.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims (8)

1. An energy-saving control method for a washing machine, characterized in that: when the washing machine is controlled to finish rinsing and dehydration and/or spin-drying and dehydration operations, the motor in the washing machine is recovered due to the induction current generated by inertial operation and the built-in electric current in the washing machine is recovered. Battery charging and energy storage, when charging the battery, first detect the size of the back electromotive force generated by the motor, the total voltage of the battery and the voltage of a single battery, and then select the corresponding voltage level according to the size of the back electromotive force The battery pack is charged and stored; when the stored electricity meets the power supply requirements required by the control circuit in the washing machine, it supplies power to the control circuit. 2. The energy-saving control method of the washing machine according to claim 1, characterized in that: after the induction current generated by the motor during the inertial operation is rectified, the battery pack is charged and stored; the battery pack is detected The total voltage of the battery pack, and when the total voltage is lower than the power supply requirement, cut off the discharge circuit of the battery pack and switch back to the main power supply for power supply. 3. The energy-saving control method of the washing machine according to claim 2, characterized in that: detecting the temperature and charging and discharging current of the battery pack, and shutting off the battery when the temperature of the battery pack is too high or the charging and discharging current is too large The charging and discharging circuit of the battery pack. 4. A washing machine, which is provided with a main power circuit, a control circuit, a motor, and a power circuit for driving the motor; it is characterized in that: the motor stops due to inertial operation when the washing machine finishes rinsing and dehydration and/or spin-drying and dehydration operations. An induced current is generated, and the induced current is rectified into a DC current by a rectifier circuit, and then transmitted to a battery pack for charging and storing energy; a controller and a voltage detection circuit are arranged in the control circuit, and the voltage detection circuit controls the battery The total voltage of the group and the voltage of a single battery are detected, and the back electromotive force generated by the motor is detected when the washing machine finishes rinsing and dehydration and/or spin-drying dehydration operations, and is fed back to the controller. The received reverse electromotive force gates the battery pack of the corresponding voltage level for charging; when the stored electricity of the battery pack meets the power supply requirement of the control circuit, the output electric energy supplies power for the control circuit. 5. The washing machine according to claim 4, wherein the voltage detection circuit detects the electric quantity stored in the battery pack and feeds it back to the controller, and the controller connects the main battery to the control circuit according to the detected electric quantity. Strobe switching is performed between the power supply loop of the power supply circuit and the power supply loop of the control circuit connected to the battery pack. 6. The washing machine according to claim 5, characterized in that: a current detection circuit and a temperature detection circuit are also provided in the control circuit to respectively detect the charging and discharging current of the battery pack and the temperature of the battery pack, and feed back to the The controller described above; when the controller detects that the temperature of the battery pack is too high or the charging and discharging current is too large, it cuts off the charging and discharging circuit of the battery pack. 7. The washing machine according to claim 6, characterized in that: a power management chip is also arranged in the control circuit, and the voltage detection circuit, current detection circuit and temperature detection circuit transmit the generated detection signals to the power management After the chip processes the digital signal, it is transmitted to the controller through the bus. 8. The washing machine according to any one of claims 4 to 7, characterized in that: the motor is a DC brushless motor; a three-phase inverter connected by six power tubes is provided in the power circuit. In the inverter circuit, a freewheeling diode is connected in reverse parallel to each power tube, and six freewheeling diodes form the rectification circuit, which rectifies and outputs the induced current output by the motor.