De-icing method using an electric motor

Abstract

The application provides an ice removing method using an electric machine, the electric machine comprising a stator, a rotor and a transmission shaft, the transmission shaft being mechanically connected with a driven component so that the driven component can be driven to rotate by the electric machine, wherein the ice removing method comprises the following steps: in response to a jam of the electric machine, acquiring an ambient temperature and a stator temperature of the electric machine; and when the ambient temperature and the stator temperature of the electric machine are lower than respective limit values, supplying an alternating current with a predefined current value and frequency to the electric machine to make the electric machine generate heat, so that the generated heat is transmitted to the driven component through the transmission shaft to remove ice from the driven component. The application also provides an electric machine suitable for executing the ice removing method according to the application and a computer program product capable of implementing the ice removing method according to the application. By using the ice removing method according to the application, ice removal of the driven component is allowed to be realized only by controlling the electric machine. This reduces the risk of failure of the electric machine and also reduces the manufacturing cost of the electric machine.

Description

Technical Field

[0001] This invention relates to the field of electromechanical engineering, and in particular to a de-icing method using an electric motor, an electric motor, and a computer program product. Background Technology

[0002] As global calls for carbon neutrality grow louder, people are increasingly opting for electric vehicles to replace existing gasoline-powered cars in order to reduce carbon emissions. In some electric vehicles, fuel cell systems that generate electricity through the electrochemical reaction of fuel and oxidant are being used more and more widely, with the proton exchange membrane fuel cell (PEMFC) system being the most representative. PEMFCs typically use hydrogen as fuel and only emit water as a reaction product. During PEMFC operation, hydrogen as fuel is supplied to the anode of the PEMFC stack and is adsorbed by the catalyst, ionizing into hydrogen ions and electrons. The hydrogen ions are transferred to the cathode via the proton exchange membrane, while the electrons flow to the cathode through an external circuit to form an electric current.

[0003] In general, to ensure uninterrupted electrochemical reactions in the battery, excess hydrogen is introduced into the anode of the fuel cell stack. This excess hydrogen then needs to be recovered and reused to improve fuel efficiency. The PEMFC fuel subsystem includes an ARB (Aeration Recirculation Circuit), which includes a hydrogen recirculation pump to pump excess hydrogen back into the fuel circuit for further electrochemical reactions.

[0004] However, since water inevitably enters the anode side of the fuel cell stack during the electrochemical reaction, the hydrogen entering the recirculation loop is also inevitably mixed with water (e.g., gaseous water, i.e., "wet" hydrogen). In this situation, when electric vehicles undergo cold starts in the low temperatures of winter, icing often occurs in the recirculation loop, especially between the impeller and housing of the hydrogen recirculation pump. Mild icing can cause a momentary increase in the instantaneous power of the hydrogen recirculation pump motor, adversely affecting motor life; severe icing can cause the impeller to completely fail to rotate, thus jamming the motor and ultimately burning out the motor or damaging the impeller.

[0005] Solutions to the icing problem include: using an additional heater to melt the ice when the motor stalls; installing additional heating elements inside the motor to generate heat; and melting the ice by allowing hot water to flow through the casing (e.g., cooling pipes with hot water). While these methods can solve the icing problem, they not only increase the cost of manufacturing the motor but may also be unsuitable for motors used in electric vehicles, and increase the risk of malfunctions such as short circuits.

[0006] Similarly, in other scenarios where motors are used, there are situations where driven parts may freeze, requiring external heating to defrost them.

[0007] Therefore, a new de-icing method is needed that can solve the icing problem without changing the existing hardware, thereby reducing costs and improving the safety factor of the motor. Summary of the Invention

[0008] The purpose of this application is to provide a de-icing method using an electric motor, an electric motor suitable for using the de-icing method, and a computer program product containing the de-icing method, in order to solve at least one problem existing in the prior art.

[0009] Therefore, according to one aspect of this application, a de-icing method using an electric motor is proposed. The electric motor includes a stator, a rotor, and a drive shaft, the drive shaft being mechanically connected to a driven component so that the driven component can be driven to rotate by the electric motor. The de-icing method includes the following steps: in response to motor jamming, acquiring the ambient temperature and the motor stator temperature; and when the ambient temperature and the motor stator temperature are below their respective limits, passing an alternating current with a predetermined current value and frequency into the motor to generate heat in the motor, such that the generated heat is transferred to the driven component via the drive shaft to de-ice the driven component.

[0010] According to another aspect of this application, an electric motor is provided, wherein the electric motor includes a stator, a rotor, a drive shaft and a control unit, the control unit being adapted to perform the de-icing method as described above.

[0011] According to another aspect of this application, a computer program product is provided, the computer program product including a computer program, wherein the computer program, when executed by a processor, implements the de-icing method as described above.

[0012] By using the method proposed in this application, existing components can be used, thus avoiding the need for additional components to assist in de-icing and significantly reducing the risk of component failure. Furthermore, since no additional components are introduced, the overall cost of the motor will be lower, and it will be more suitable for scenarios where additional components cannot be installed. Attached Figure Description

[0013] Exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be understood that the embodiments described below are for illustrative purposes only and are not intended to limit the scope of this application. In the accompanying drawings:

[0014] Figure 1 A portion of a fuel cell system is shown, comprising an electric motor using a de-icing method according to an exemplary embodiment of this application;

[0015] Figure 2 A schematic diagram of a hydrogen circulation pump using a de-icing method according to an exemplary embodiment of this application is shown;

[0016] Figure 3 A flowchart of a de-icing method according to an exemplary embodiment of this application is shown;

[0017] Figure 4 The circuit diagram shows a motor comprising a hydrogen circulation pump using a de-icing method according to an exemplary embodiment of this application; and

[0018] Figure 5 A flowchart of a de-icing method according to another exemplary embodiment of this application is shown. Detailed Implementation

[0019] Preferred embodiments of this application are described in detail below with reference to examples. In the embodiments of this application, the motor of a hydrogen circulation pump in the recirculation loop of a hydrogen fuel cell system is used as an example for description. However, those skilled in the art should understand that these exemplary embodiments do not imply any limitation on this application. Furthermore, features in the embodiments of this application can be combined with each other unless otherwise specified. In different drawings, the same elements are represented by the same reference numerals, and other elements are omitted for brevity, but this does not mean that the motor of this application cannot include other components or that the method of this application cannot include other steps. It should be understood that the dimensions, scale relationships, and number of components in the drawings are not intended to limit this application.

[0020] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of this application.

[0021] The following section uses the motor of a hydrogen circulation pump used in a hydrogen fuel cell system as an example to describe this method in detail.

[0022] Hydrogen fuel cell systems can be used in vehicles to provide electricity, thereby driving the vehicle's electric motor to provide power or enabling onboard systems to perform various functions. Figure 1 A portion of a hydrogen fuel cell system is schematically shown, including a recirculation loop for an electric motor controlled using this method.

[0023] Figure 1 A portion of the hydrogen fuel cell system shown may include a fuel cell stack and a hydrogen supply system (such as...) Figure 1(Indicated by the dashed box in the diagram). The fuel cell stack 100 includes an anode 110 and a cathode 120. During operation of the hydrogen fuel cell system, as schematically indicated by arrow 11, hydrogen from a hydrogen source 200, such as a hydrogen tank, is supplied to the input 111 of the anode 110 via a hydrogen supply device 310 (e.g., an ejector) of the hydrogen supply system. Air is supplied to the cathode 120. Hydrogen atoms entering the anode 110 are adsorbed by a catalyst and ionized into hydrogen ions and electrons. The hydrogen ions are transferred to the cathode 120 via a proton exchange membrane (not shown), and the electrons flow to the cathode 120 through an external circuit (not shown) to form an electric current. Oxygen in the air combines with hydrogen ions and electrons at the cathode 120 to form water molecules. Typically, during operation of the hydrogen fuel cell system, excess hydrogen is supplied to the input 111 of the anode 110 to ensure that all cells in the fuel cell stack 100 have sufficient hydrogen available. Product water, unconsumed hydrogen, and waste gases accumulate at the output 112 of the anode 110. As used herein, the term "inactive gas" refers to a gas that does not participate in the reaction, primarily nitrogen.

[0024] Please continue to refer to this. Figure 1 The recirculation loop 300 is arranged between the output 112 of the anode 110 and the hydrogen supply device 310 for receiving the recirculation flow 12 from the output 112 of the anode 110 of the fuel cell stack 100 and circulating the recirculation flow 12 to the hydrogen supply device 310 during operation of the hydrogen fuel cell system. As used herein, the recirculation flow 12 refers to a fluid mixture comprising product water, unconsumed hydrogen, and ineffective gases.

[0025] The recirculation loop 300 includes a hydrogen separator 320 configured to physically separate at least a portion of the hydrogen from the recirculation stream 12 as it passes through, allowing the separated hydrogen to flow to a hydrogen supply device 310 (illustratively indicated by arrow 12a), and discharging the remaining components of the recirculation stream 12, excluding the separated hydrogen, from the hydrogen fuel cell system (illustratively indicated by arrow 12b). As used herein, “physically separating at least a portion of the hydrogen from the recirculation stream” means physically separating at least a portion of the hydrogen from the recirculation stream using physical methods, without any chemical reaction, by means of the different physical properties of hydrogen and other components in the recirculation stream.

[0026] In the process of supplying the separated hydrogen to the hydrogen supply device, a hydrogen circulation pump 330 is usually provided to pressurize the separated hydrogen and push it to the hydrogen supply device 310. Figure 2 A schematic diagram of a hydrogen circulation pump 330 is shown.

[0027] like Figure 2As shown, the hydrogen circulation pump 330 includes at least an impeller 331, a drive shaft 332 mechanically connected to the impeller 331, and a motor 333 (not shown in detail) that drives the drive shaft to rotate. The impeller 331 is housed within a circulation pump housing 334. As indicated by the arrows, the separated hydrogen enters the hydrogen circulation pump 330 in the direction of the arrows and is pressurized at the impeller 331, then flows to the hydrogen supply device 310. It can be seen that there is a gap between the impeller 331 and the circulation pump housing 334, where icing is most likely to occur at low temperatures. The motor can be a common permanent magnet three-phase motor with a stator and a rotor (not shown). The rotor is connected to the drive shaft 332, thereby generating torque and driving the driven component to rotate (in this example, the driven component is the impeller 331). When icing occurs at the aforementioned gap, the impeller 331 can no longer rotate, causing the motor 333 to jam and damaging the hydrogen circulation pump 330. At this time, the jammed motor can be advantageously de-iced using the method according to this application.

[0028] Figure 3 A flowchart illustrating a de-icing method according to an illustrative embodiment of this application is shown.

[0029] The de-icing method includes step S1: receiving a motor start request. Typically, the motor start request originates from the vehicle control system's start request for each subsystem when the electric vehicle is started. Alternatively, it is conceivable to have a dedicated icing monitoring system that determines the icing status of the driven components connected to the motor by starting the motor.

[0030] Upon receiving a motor start request, the de-icing method proceeds to step S2 to determine if the motor is jammed. As mentioned above, iced driven components will cause the motor to jam. Therefore, for motors that are not jammed, de-icing is obviously unnecessary; only jammed motors require de-icing. Whether the motor is jammed can be determined by changes in output power.

[0031] In response to the jamming of motor 333, the method according to an exemplary embodiment of this application proceeds to step S3. In step S3, the ambient temperature and the motor stator temperature are acquired. The ambient temperature can be provided by a temperature sensor of the hydrogen fuel cell system, or alternatively, by a temperature sensor of the electric vehicle. That is, the ambient temperature is not limited to being near the motor or driven component, but can also be the temperature measured by the system containing the motor or driven component. However, it is understood that, preferably, the ambient temperature should be measured near the driven component or motor 333. Similarly, the motor stator temperature is obtained by a motor temperature sensor, without the need for additional temperature sensors.

[0032] After obtaining the ambient temperature and the motor stator temperature, these two temperatures are judged. For example, it can be envisioned that when the ambient temperature is above a certain temperature (which depends, for example, on the working environment of the driven parts or the part to be de-iced), icing is unlikely to occur under any circumstances. Therefore, this method will only proceed to subsequent steps when the ambient temperature is below a certain temperature (limit). This judgment logic also applies to the motor stator temperature. Due to motor 333 jamming, the power of motor 333 will be entirely dissipated as heat, so when the motor stator temperature is too high, the winding coils are at risk of burning out. Therefore, when the motor stator temperature is too high, the subsequent steps of this method cannot be performed.

[0033] When the ambient temperature and the motor stator temperature are below their respective limits, the de-icing method proceeds to step S4: an alternating current with a predetermined current value and frequency is supplied to the motor 333. Preferably, the same energizing method as during normal motor operation is used, thereby avoiding the need for additional parts or components. However, other energizing methods are also contemplated, which will be discussed later. Figure 4 Let me explain further.

[0034] Subsequently, the generated heat is transferred to the driven component via the drive shaft 332 to de-ice the driven component. When heat is generated in the coil, its temperature rises, causing the overall stator temperature to rise, which in turn heats the motor 333 and the drive shaft 332, raising the temperature of the drive shaft 332. The heated drive shaft 332 then transfers heat to the impeller 331 connected to it, thereby heating the impeller 331 and ultimately causing the ice between the impeller 331 and the circulating pump housing 334 to melt. Since the heat is transferred from the motor 333 to the impeller 331 via simple thermal conduction, some heat remains in the conduction path during this process. This "lost" heat effectively heats the ambient temperature around the driven component (impeller 331), thus not only preventing possible icing inside the driven component but also significantly reducing icing around it. In other words, the self-heating of the motor can de-ice not only the driven component directly mechanically connected to the motor but also components near the motor or connected to the driven component. Thus, by using the de-icing method according to this application, de-icing of the driven component and its surrounding components is performed solely through the control of the motor without the addition of any other components. Furthermore, once the icing has been eliminated, the driven component can immediately enter working condition under the drive of the motor. At this point, the motor's power shifts from generating heat to providing torque, thereby preventing potential damage to the coils or stator due to overheating.

[0035] According to some exemplary embodiments of this application, the de-icing method further includes step S5: obtaining the motor rotor temperature. Similar to the motor stator, the motor rotor should also be protected from damage due to overheating. Although the rotor itself does not generate heat, the heat radiated by the stator is sufficient to raise the rotor temperature. Therefore, in the method of this application, it is also necessary to monitor the rotor temperature. The rotor temperature can be obtained directly through the motor's own temperature monitoring system or through an additional temperature monitoring device, or it can be indirectly calculated from the internal temperature of the motor.

[0036] After obtaining the motor rotor temperature, based on the motor rotor and stator temperatures, step S6 is then performed to determine the predetermined current value and frequency of the applied alternating current, as well as the de-icing time. Due to the characteristics of alternating current, the coil can be considered as an equivalent resistance (inductance). Therefore, the heat generated in the coil can be simplified as being proportional to the current value and frequency passing through the coil. Thus, it is conceivable that when the stator or rotor temperature is too high, a lower current value and lower frequency can be applied, or a shorter de-icing time can be set, thereby preventing overheating damage to components; while when the stator and rotor temperatures are low, a higher current value and higher frequency can be applied to complete the de-icing step as quickly as possible, or a longer de-icing time can be set to complete the de-icing step in extreme cases. Preferably, the ambient temperature can also be referenced to make a preliminary judgment on the de-icing time. Based on different motor models and the aforementioned stator and rotor temperatures, the predetermined current value and frequency of the alternating current can be determined. For example, in the case of the hydrogen circulation pump 330 of this application, the value of the alternating current can be 30A to 60A, such as 30A or 60A or some intermediate value, and the frequency of the alternating current can be 500Hz to 1500Hz, such as 500Hz or 1500Hz or some intermediate value. The specific current value and frequency are preferably determined through simulation and experimental data.

[0037] Furthermore, the aforementioned limits for ambient temperature and motor stator temperature can also be determined through simulation and experimental data. Normally, icing will not occur when the ambient temperature is above 0 degrees Celsius. However, due to differences in air pressure, icing temperatures may exceed 0 degrees Celsius. Therefore, preferably, the ambient temperature limit is set to 5 degrees Celsius; that is, it is assumed that icing will not occur when the ambient temperature is above 5 degrees Celsius, and conversely, icing may occur below 5 degrees Celsius, requiring the use of the de-icing method according to this application. As for the motor stator temperature, preferably, the motor stator temperature should not exceed 165 degrees Celsius, otherwise there is a risk of burnout.

[0038] However, not all situations are suitable for starting or continuing the de-icing method according to this application. Besides the aforementioned situations where the stator or rotor temperature is too high or the ambient temperature exceeds the limit, as mentioned above, whether the motor 333 is stuck is also an important basis for determining whether to start or continue the de-icing method according to this application. For a motor that is not stuck, it is obviously difficult for ice to form at the driven component connected to it. Alternatively, after the de-icing process has been running for a certain period of time, as the ice formation at the driven component gradually disappears, the driven component can begin to move, thereby freeing the motor 333 from sticking. In these cases, the de-icing method according to this application will proceed to step S8: the de-icing method ends. Simultaneously, based on the input control parameters, the motor 333 is energized to allow the motor 333 to operate normally.

[0039] The previous section described how using a normal energizing method to self-heat the motor 333 enables de-icing of the driven components connected to the motor 333. In the aforementioned embodiment, although the current value and frequency of the alternating current supplied to the motor 333 can be determined based on the obtained ambient temperature and motor stator temperature, this energizing method is still sufficient to operate the motor 333. That is, it may cause the motor 333 to burn out if the output is limited (motor jamming). Furthermore, the current value used in this method is significantly higher than that used by a normally operating motor, increasing the risk of burning out the motor 333 or the battery supplying it. The following section describes another energizing method that periodically heats the stator using different coils, thereby minimizing the possibility of coil burnout.

[0040] Figure 4 The diagram illustrates the power supply circuit for the motor. Typically, in electric vehicle systems, the motor connected to the hydrogen recirculation pump is powered by a battery, Ud. The battery Ud provides direct current (DC), which is converted to alternating current (AC) usable by the motor via an inverter. The inverter... Figure 4 The circuit is simplified to consist of six switching transistors, with each pair of transistors positioned on a bridge arm (i.e., the first bridge arm includes the first switching transistor Q1 and the second switching transistor Q2, the second bridge arm includes the third switching transistor Q3 and the fourth switching transistor Q4, and the third bridge arm includes the fifth switching transistor Q5 and the sixth switching transistor Q6). Each bridge arm is correspondingly connected to one phase of the motor's three-phase windings (first winding U, second winding V, and third winding W) and together connected to the battery Ud. The switching transistors can be, for example, insulated-gate bipolar transistors (IGBTs) or metal-oxide-semiconductor effect transistors (MOSFETs). As can be seen, the circuit consists of the existing motor drive circuit and components, requiring no additional components or wiring. Although not shown in the figures, the connection of the motor windings does not affect the implementation of the method described in this application.

[0041] During heating, the de-icing method of this application causes the motor to periodically switch between a first step, a second step, and a third step at predetermined time intervals. The predetermined time interval can be, for example, 10 seconds. In the first step, the circuit switches between a state where the first switch Q1 and the fourth switch Q4 are on and the second switch Q2 and the third switch Q3 are off, and a state where the second switch Q2 and the third switch Q3 are on and the first switch Q1 and the fourth switch Q4 are off, at a predetermined frequency, while the fifth switch Q5 and the sixth switch Q6 remain off (i.e., switching between a state where only the first switch Q1 and the fourth switch Q4 are on and a state where only the second switch Q2 and the third switch Q3 are on, at a predetermined frequency). In this way, the first winding U and the second winding V of the motor 333 are used and heated, while the third winding W remains without current. In the second step, the circuit switches between a state where the first switch Q1 and the sixth switch Q6 are on and the second switch Q2 and the fifth switch Q5 are off, and a state where the second switch Q2 and the fifth switch Q5 are on and the first switch Q1 and the sixth switch Q6 are off, at a predetermined frequency, while the third switch Q3 and the fourth switch Q4 remain off (i.e., switching between a state where only the first switch Q1 and the sixth switch Q6 are on and a state where only the second switch Q2 and the fifth switch Q5 are on, at a predetermined frequency). In this way, the first winding U and the third winding W of the motor are used and generate heat, while the second winding V remains without current. In the third step, the circuit switches between a state where the third switch Q3 and the sixth switch Q6 are on and the fourth switch Q4 and the fifth switch Q5 are off, and a state where the fourth switch Q4 and the fifth switch Q5 are on and the third switch Q3 and the sixth switch Q6 are off, at a predetermined frequency, while the first switch Q1 and the second switch Q2 remain off (i.e., switching between a state where only the third switch Q3 and the sixth switch Q6 are on and a state where only the fourth switch Q4 and the fifth switch Q5 are on, at a predetermined frequency). In this way, the second winding V and the third winding W of the motor are used and heated, while the first winding U remains without current flow. In this manner, without using additional components and wiring, the windings can be heated using a lower alternating current value and a lower frequency (thus heating the stator of the motor). Meanwhile, since in each step, at any given time, one phase winding is not conducting electricity (the current flowing through that phase winding is 0), and the non-conducting time is much longer than the non-conducting time during normal operation, the temperature of each phase winding will not become too high, thereby preventing the winding from burning out. In other exemplary embodiments according to this application, the de-icing method may also perform only the first, second, or third step, thereby protecting a specific phase winding from overuse under adverse conditions (e.g., localized corrosion).

[0042] Now back Figure 3 In some cases, the degree of icing on the driven component may be so high that a single de-icing operation (i.e., one de-icing cycle, including at least steps S1 to S4) cannot completely melt the ice, and the driven component may still be icy (the driven component cannot rotate). Therefore, after the de-icing operation is performed within a predetermined time, the de-icing method also includes determining again whether the driven component needs to be de-iced. The determination method is the same as the aforementioned determination method, that is, obtaining the ambient temperature and the motor stator temperature, and comparing the ambient temperature with the motor stator temperature. If both the ambient temperature and the motor stator temperature are lower than their respective limits, and the motor is still stuck, it is determined that icing still occurs, and further de-icing of the driven component is required. At this time, the de-icing method again uses an appropriate method to heat the motor, thereby achieving de-icing of the driven component. That is, after the de-icing is completed, steps S1 to S3 are performed again. If the determination result still requires de-icing, step S4 is repeated; otherwise, the de-icing method ends, and step S8 is entered, and the de-icing method ends (i.e., the motor 333 (hydrogen circulation pump 330) is started normally).

[0043] It should be noted that in the cases described above, the jamming of motor 333 is presumed to be caused by icing. However, in other cases, the jamming of motor 333 may be due to mechanical failure, such as jamming of drive shaft 332 or impeller 331 breaking and causing restricted rotation. In these cases, it is desirable to detect these failures as soon as possible rather than allowing the motor to rotate and causing further damage. Therefore, the de-icing operation (i.e., repeating steps S1 to S4 indefinitely) will not be performed. Experimental data shows that after three cycles of the de-icing method, almost no icing remains at the driven part. Therefore, it is conceivable that if motor jamming still occurs after three cycles, such motor jamming is not caused by icing. Therefore, preferably, as Figure 5 As shown, the de-icing method according to another embodiment of this application further includes step S7 after step S4: determining whether the de-icing cycle (steps S1 to S4) has been performed three times. When three de-icing operations have been performed, it can be determined that the motor 333 or its connected components have experienced other mechanical failures and require repair, or that the icing phenomenon has disappeared, thus proceeding to step S8: ending the de-icing method. Conversely, if three de-icing cycles have not been performed, steps S1 to S4 are repeated. The maximum number of de-icing operations can vary depending on the usage environment and motor type, and can be set according to specific circumstances.

[0044] In summary, the embodiments of this application provide a de-icing method using an electric motor. According to the technical solution of this application, by obtaining and judging the ambient temperature, motor stator temperature, and motor jamming status, the motor is heated, and the generated heat is used to melt the ice at the driven parts to perform the de-icing operation. Using this de-icing method, existing components can be used, advantageously avoiding the use of additional components to assist in de-icing, thereby significantly reducing the risk of component failure. At the same time, since no additional components are introduced, the overall cost of the motor will be lower, and it will be more suitable for scenarios where additional components cannot be installed.

[0045] According to another aspect of this application, an electric motor is provided, comprising a stator, a rotor, a drive shaft, and a control unit, wherein the control unit is adapted to perform the aforementioned de-icing method, such that icing at components connected to the motor can be eliminated solely by heating the motor without the need for additional components. For example, the motor may be the motor 333 for the hydrogen circulation pump 330 described in the above embodiments. Alternatively, the motor may be a motor connected to a cooling fan of an electric vehicle, or any other motor connected to a driven component that may ic up.

[0046] According to another aspect of this application, a computer program product is also provided, the computer program product including a computer program that can be executed by a processor to implement the above-described de-icing method.

[0047] By using the motor or computer program product according to this application, it is possible to de-ice the driven parts solely through the control of the motor without adding any other components. This reduces the risk of motor failure and also lowers the manufacturing cost of the motor.

[0048] The present application has been described in detail above with reference to specific embodiments. Obviously, the above description and the embodiments shown in the accompanying drawings should be understood as exemplary and not as limiting the present application. Those skilled in the art can make various modifications or alterations without departing from the spirit of the present application, and such modifications or alterations do not depart from the scope of the present application.

Claims

1. A de-icing method using an electric motor, the motor (333) comprising a stator, a rotor, and a drive shaft (332), the drive shaft being mechanically connected to a driven component such that the driven component can be driven to rotate by the motor, characterized in that, The de-icing method includes the following steps: In response to the motor jamming, the ambient temperature and the motor stator temperature are acquired; and When the ambient temperature and the motor stator temperature are below their respective limits, an alternating current with a predetermined current value and frequency is passed through the motor to generate heat, and the generated heat is transferred to the driven component via the drive shaft to de-ice the driven component.

2. The de-icing method according to claim 1, characterized in that, The de-icing method also includes: Before applying the alternating current to the motor, the rotor temperature of the motor is obtained; and Based on the motor rotor temperature and the motor stator temperature, the current value and frequency of the alternating current and the de-icing time are determined.

3. The de-icing method according to claim 2, characterized in that, The alternating current has a current value range of 30A to 60A and a frequency range of 500Hz to 1500Hz.

4. The de-icing method according to any one of claims 1 or 3, characterized in that, The limit for ambient temperature is 5 degrees Celsius, and the limit for motor stator temperature is 165 degrees Celsius.

5. The de-icing method according to claim 1, characterized in that, If the ambient temperature or the motor stator temperature is not lower than its respective limit or the motor is not stuck, the de-icing method ends.

6. The de-icing method according to claim 1, characterized in that, The circuit of the motor includes a first bridge arm connected to a first winding (U), a second bridge arm connected to a second winding (V), and a third bridge arm connected to a third winding (W). The first bridge arm includes a first switch (Q1) and a second switch (Q2), the second bridge arm includes a third switch (Q3) and a fourth switch (Q4), and the third bridge arm includes a fifth switch (Q5) and a sixth switch (Q6). Generating heat in the motor also includes controlling the motor to heat the coils in a periodic, stepwise manner as follows: First step: Switch the circuit between a state where only the first and fourth switching transistors are turned on and a state where only the second and third switching transistors are turned on at a predetermined frequency; The second step: Switching the circuit between a state where only the first and sixth switches are on, and a state where only the second and fifth switches are on, at a predetermined frequency; and The third step: to switch the circuit between a state where only the third and sixth switches are turned on and a state where only the fourth and fifth switches are turned on at a predetermined frequency.

7. The de-icing method according to claim 1, characterized in that, The de-icing method also includes performing the de-icing process a maximum of three times, after which the de-icing method ends.

8. The de-icing method according to claim 1, characterized in that, The driven component is an impeller (331) connected to the drive shaft, and the de-icing method is adapted to remove ice formed between the impeller and the circulating pump housing (334) surrounding the impeller.

9. An electric motor, characterized in that, The motor includes a stator, a rotor, a drive shaft, and a control unit, the control unit being adapted to perform the de-icing method according to any one of claims 1 to 8.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the de-icing method according to any one of claims 1 to 8.

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