Electric compressor and control method thereof

Abstract

Disclosed are an electric compressor and a control method thereof. The present embodiment provides logic for protection before an inverter element of an inverter portion provided in an electric compressor is damaged due to overheating, and enables stable operation of the electric compressor to ensure stability.

Description

Technical Field

[0001] The present invention is used to prevent the inverter section of an electric compressor from overheating and becoming a high temperature. More specifically, it relates to an electric compressor and a control method thereof. Background Technology

[0002] Generally, the compressor used in a car's air conditioning system draws in refrigerant that has completed evaporation from the evaporator, converts it into a high-temperature, high-pressure state that is easily liquefied, and then passes it to the condenser. Such compressors can be either reciprocating or rotary, where the structure that compresses the refrigerant performs compression.

[0003] The aforementioned rotary compressors are divided into mechanical types, which use an engine as a drive source to perform rotation, and electric types, which use an electric motor as a drive source.

[0004] Regarding refrigerants, during periods of low outside temperature, such as seasonal changes or winter, the refrigerant temperature drops below its boiling point, resulting in a phase change from gaseous to liquid. While compressors can compress gaseous refrigerants, they cannot compress liquid refrigerants. Therefore, when liquid refrigerants flow in, the fluid resistance causes a gradual accumulation of fatigue in the compression system.

[0005] When liquid compression begins in the compressor of an air conditioning system, the pressure and enthalpy of the refrigerant rise and the refrigerant changes to a gaseous state. The time required until this point has a significant impact on determining the durability of the compressor.

[0006] Among them, the electric compressor is a compressor with a scroll compressor. The motor is connected to the compressor, so the refrigerant is compressed as the motor drives it. The motor drive is controlled by an inverter on the printed circuit board.

[0007] The aforementioned electric compressor generates heat during operation. This heat continues to be generated during operation, especially under high load conditions. As the motor speed increases, more heat is generated in multiple components such as the motor and inverter, causing the temperature of the electric compressor to rise significantly.

[0008] Excessive temperature rise in such electric compressors can cause damage to multiple components of the electric compressor. Therefore, methods such as cooling the electric compressor by installing a heat sink to dissipate heat to the outside or sometimes stopping the electric compressor to reduce heat generation are used.

[0009] However, even if the temperature of the electric compressor is reduced through such a process, the energy efficiency of the electric compressor is low because the waste heat is directly discarded.

[0010] Furthermore, when the electric compressor is driven under high load conditions, the rapid temperature rise also affects the driving performance, resulting in a performance degradation problem as the maximum speed per minute of the electric compressor decreases. Here, "high load conditions" can be an example of a high-temperature state where the outside air temperature remains around 50 degrees Celsius while the vehicle is parked, or a state where the vehicle is parked in the field under direct sunlight, but it can also include other conditions.

[0011] The air conditioning system installed in the aforementioned vehicles draws in the refrigerant that has completed evaporation in the evaporator, converts it into a high-temperature, high-pressure state that is easily liquefied, and then passes it to the condenser.

[0012] The electric compressor mentioned above generates heat during the driving process, and this heat continues to be generated during the driving process. Especially when driven under high load conditions, as the motor speed increases, more heat is generated in multiple parts such as the motor and inverter, resulting in a significant increase in the temperature of the electric compressor.

[0013] Excessive temperature rise in this type of electric compressor can cause damage to multiple components of the electric compressor. Therefore, methods such as cooling the electric compressor by installing a heat sink to dissipate heat to the outside or sometimes stopping the electric compressor to reduce heat generation are used.

[0014] As an example, the inverter described above is configured to include a motor drive circuit and a control unit. There is a situation where the motor drive circuit becomes hot due to the heat generated by the semiconductor switching elements and other components constituting the circuit.

[0015] In this situation, the current control value of the semiconductor components inside the inverter decreases due to high temperature. When a current exceeding the control value flows, the semiconductor components may break. Furthermore, since the electric compressor is located in the engine compartment, the inverter may also become hot due to the heat generated by the engine.

[0016] To prevent overheating of such inverters, the compressor was previously stopped when the inverter temperature rose above a predetermined temperature until the inverter temperature dropped sufficiently to protect the inverter. However, there is still a risk of damage, so countermeasures are needed. Summary of the Invention

[0017] Technical issues

[0018] This embodiment provides an electric compressor and its control method for reliably preventing damage to the inverter section of an electric compressor due to overheating.

[0019] Technical solution

[0020] The control method for the electric compressor based on this embodiment includes: a first step, including a step of judging the current discharge pressure state of the electric compressor when the air conditioning in the vehicle is on; a second step, judging the current speed per minute information, inverter temperature information, and phase current information of the electric compressor when the discharge pressure is equivalent to overload pressure; a third step, maintaining the high temperature error signal on when the inverter is in an overheated state; and a fourth step, judging whether the electric compressor is operating based on the discharge pressure of the inverter after the high temperature error signal is on.

[0021] The first step mentioned above also includes a cooling fan operation confirmation step, which confirms whether the cooling fan installed in the vehicle is working.

[0022] The first step mentioned above also includes an inverter section temperature detection step, which detects the current temperature of the inverter section when the output pressure is below the overload pressure.

[0023] The second step mentioned above includes: a speed per minute determination step, which determines the current speed per minute status of the electric compressor; an inverter temperature determination step, which determines whether the temperature of the inverter is equivalent to the set overheating temperature range; and a phase current determination step, which determines whether the phase current of the electric compressor is maintained above a certain value.

[0024] The aforementioned speed per minute determination step is characterized by being equivalent to the electric compressor operating at a speed of less than 1000 RPM.

[0025] The inverter temperature determination step described above is characterized by being equivalent to either the inverter temperature being higher than the outside air temperature or maintaining a temperature above a first temperature.

[0026] The above phase current determination steps are equivalent to maintaining the first current value or higher.

[0027] The second step above is equivalent to the situation where the current speed per minute of the electric compressor is low. When the temperature of the inverter section is maintained within the overheating temperature range and the phase current is maintained above a certain value, it is determined that the inverter section is in an overheating state.

[0028] The third step mentioned above also includes a step of switching to a state where the high temperature error signal is turned on while the operation of the electric compressor is temporarily stopped.

[0029] The third step mentioned above also includes a high-temperature error standby step, which maintains the standby state during the first time period after a high-temperature error code is generated.

[0030] Following step 3 above, step 4 above also includes a reconfirmation step of the discharge pressure, which reconfirms the discharge pressure after the first time.

[0031] The fourth step described above is characterized in that, after the above-mentioned discharge pressure reconfirmation is achieved, and the discharge pressure continues to be maintained above the predetermined pressure, the process moves to before the above-mentioned discharge pressure reconfirmation step.

[0032] The fourth step above includes the following steps: after moving to the above-mentioned discharge pressure reconfirmation step, when the discharge pressure continues to maintain the predetermined pressure, the vehicle power is switched to the off state.

[0033] Step 4 above also includes the following step: restarting the electric compressor when the pressure is below the predetermined pressure in the above discharge pressure reconfirmation step.

[0034] After the electric compressor is restarted, proceed to step 1 above to reconfirm the discharge pressure status.

[0035] A control method for an electric compressor based on another embodiment of the present invention includes: a first step, comprising determining the current discharge pressure state of the electric compressor when the air conditioning in the vehicle is on; a second step, simultaneously determining the current rotational speed per minute of the electric compressor, the temperature information of the inverter section, the phase current information, the temperature rise rate of the inverter section, and the cumulative time information when the discharge pressure is equivalent to an overload pressure; a third step, maintaining the high temperature error signal on when the inverter section becomes overheated; and a fourth step, determining whether the electric compressor is operating based on the discharge pressure of the inverter section after the high temperature error signal is on.

[0036] The electric compressor based on this embodiment includes: a compression section having a compressor for compressing refrigerant; a motor section having a motor attached to one side of the compression section and providing driving force to the compressor; an inverter section having an inverter attached to one side of the motor section and providing control over the motor section; a detection section for detecting the discharge pressure of the compression section, the rotational speed per minute, the temperature of the inverter section, the phase current applied to the compression section, and the rate of temperature rise of the inverter section; and a control section for receiving input from the information detected in the detection section and determining the overheating state of the inverter section.

[0037] The control unit, together with the information detected in the detection unit, simultaneously receives information on whether the cooling fan installed in the vehicle is operating, and determines whether the inverter unit is overheating.

[0038] Invention Effects

[0039] In this embodiment, in a vehicle equipped with an electric compressor, after the inverter is switched to a stopped state before it is damaged due to overheating, it can be restarted or stopped based on the discharge pressure state, thereby improving stability.

[0040] In this embodiment, the input of the overheating judgment condition of the inverter section is received more accurately, thereby enabling the electric compressor to be controlled before the failure of the inverter components or immediately after the inverter section overheats.

[0041] In this embodiment, control stability is maintained consistently even when the electric compressor is operating normally or when the inverter is not operating normally due to overheating, thereby improving durability. Attached Figure Description

[0042] Figure 1 This is a sequence diagram illustrating the control method of the electric compressor based on this embodiment.

[0043] Figure 2 Based on Figure 1 Work sequence diagram.

[0044] Figure 3 This is a sequence diagram illustrating a control method for an electric compressor based on another embodiment of the present invention.

[0045] Figure 4 This is a graph showing the rate of temperature rise of the inverter section based on this embodiment and the corresponding conditions.

[0046] Figure 5 This is a perspective view showing the electric compressor based on this embodiment.

[0047] Figure 6 This is a diagram showing the control unit and surrounding structure based on this embodiment. Detailed Implementation

[0048] By reference and appendix Figure 1 The detailed description of the embodiments will make the advantages, features, and methods of implementing this disclosure clear. However, this disclosure is not limited to the embodiments disclosed below, and can be implemented in various ways, different from each other. These embodiments are provided only to improve the disclosure and to fully inform those skilled in the art of the scope of the disclosure, which is defined only by the scope of the claims. Throughout the specification, the same reference numerals denote the same constituent elements.

[0049] A component being "connected to" or "coupled to" another component includes cases where it is directly connected to or coupled to another component, or cases where other components are involved in the connection. Conversely, a component being "directly connected to" or "directly coupled to" another component means that no other components are involved in the connection. "And / or" includes each of the multiple items mentioned, as well as all combinations of more than one.

[0050] The terminology used in this specification is for illustrative purposes and is not intended to limit this disclosure. In this specification, unless otherwise specified, a single form of statement also includes multiple forms. The terms "comprises" and / or "comprising" as used in this specification do not exclude the presence or addition of more than one other constituent element, step, action, and / or element mentioned.

[0051] Although terms like "first," "second," etc., are used to describe various constituent elements, these constituent elements are certainly not limited to these terms. These terms are used only to distinguish one constituent element from another.

[0052] The control method for the electric compressor based on this embodiment will be described with reference to the accompanying drawings. For reference, Figure 1 This is a sequence diagram illustrating the control method of the electric compressor based on this embodiment. Figure 2 Based on Figure 1 Work sequence diagram.

[0053] Reference Figure 1 and Figure 2 The control method for the electric compressor based on this embodiment operates under conditions where the cooling of the inverter section becomes unstable or the cooling fan is not working due to a lack of refrigerant in the vehicle's air conditioning system or insufficient intake of refrigerant.

[0054] In addition, this embodiment prevents the inverter components from being damaged due to overheating when the electric compressor operates under conditions where the outside air temperature is maintained at around 50 degrees Celsius and the vehicle is directly exposed to sunlight.

[0055] Therefore, this embodiment includes: a first step (ST100), which includes determining the current discharge pressure state of the electric compressor when the air conditioning in the vehicle is on (ST110); a second step (ST200), which, when the discharge pressure is equivalent to the overload pressure, determines the current speed per minute information of the electric compressor, the temperature information of the inverter section, and the phase current information; a third step (ST300), which, when the inverter section is in an overheated state, maintains the high temperature error signal on (ST400); and a fourth step (ST400), which, after the high temperature error signal is on (ST400), determines whether the electric compressor is working based on the discharge pressure of the inverter section.

[0056] The first step (ST100) mentioned above also includes a cooling fan operation confirmation step (ST120) to confirm whether the cooling fan installed in the vehicle is working. When the air conditioning system installed in the vehicle is working normally, outside air is supplied to the condenser through the cooling fan, thereby cooling the condenser and lowering its temperature to induce a phase change in the refrigerant.

[0057] If the aforementioned cooling fan is not operating, external air is not supplied to the condenser, thereby interrupting cooling of the condenser and maintaining a high-temperature state. In the aforementioned electric compressor, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor undergoes a phase change to a liquid refrigerant state in the condenser, converting into a liquid refrigerant while stably achieving cooling based on external air.

[0058] If the cooling fan is not working, the refrigerant exists in the condenser in a high-temperature, high-pressure gaseous state, causing the temperature of the electric compressor to rise sharply to a high temperature, and the temperature of the inverter section also rises at the same time. Therefore, the operation of the cooling fan is an important condition that can prevent damage or failure of the inverter components.

[0059] This embodiment also includes an inverter section temperature detection step (ST130) that detects the current temperature of the inverter section when the output pressure is below the overload pressure. Regarding the aforementioned overload pressure, although 350 psi is used as an example for explanation, it can be changed according to design conditions.

[0060] When the electric compressor is operating under normal conditions, although the discharge pressure does not maintain an overload pressure state, it is judged to discharge at a discharge pressure of 350 psi or higher and the current discharge pressure becomes an overload pressure state under conditions equivalent to the outside air temperature maintaining around 50 degrees Celsius when the cooling fan is not working and the vehicle is directly exposed to sunlight, as described above.

[0061] If the output pressure is below the overload pressure, the current temperature of the inverter section is detected (ST130) to determine whether overheating has occurred.

[0062] For example, when the inverter section temperature is above 125 degrees Celsius, the high temperature error signal is kept on (ST132). Furthermore, the temperature and output pressure of the inverter section are reassessed to determine whether the inverter section is actually overheated, thereby reconfirming whether the inverter section is overheated (ST134).

[0063] If the temperature of the inverter section is measured to be below 115°C and the discharge pressure is below 275 psi, the electric compressor will restart.

[0064] In this embodiment, as described above, when the electric compressor is working normally, the discharge pressure and inverter temperature are judged to keep the electric compressor working continuously. Conversely, if the discharge pressure is still above 350 psi, it is equivalent to the inverter overheating and not working normally.

[0065] In this embodiment, even if the electric compressor is operating abnormally, logic can be implemented to prevent malfunctions caused by overheating of the inverter section, and this will be explained.

[0066] The second step (ST200) mentioned above includes: a speed per minute determination step (ST210), which determines the current speed per minute of the electric compressor under conditions equivalent to overload pressure; an inverter section temperature determination step (ST220), which determines whether the temperature of the inverter section is equivalent to the set overheating temperature range; and a phase current determination step (ST230), which determines whether the phase current of the electric compressor is maintained above a certain value.

[0067] In this embodiment, instead of judging whether the electric compressor is overheating solely by outputting pressure information, the system simultaneously judges the electric compressor's speed per minute, whether the inverter temperature is within the overheating range, and the phase current status. This allows for accurate determination of whether the inverter components are actually maintaining an overheating state, thereby preventing damage to the inverter components and ensuring stable operation of the electric compressor.

[0068] As an example, the above-mentioned speed per minute determination step (ST210) corresponds to the case where the speed per minute of the electric compressor is below 1000 RPM. The above-mentioned 1000 RPM refers to the case where the vehicle is parked and the compressor is operating at a low speed, which corresponds to the case where the pressure and temperature inside the electric compressor are at a high temperature and high pressure.

[0069] When the electric compressor operates at a speed of 1000 RPM, the circulation of refrigerant decreases compared to normal conditions, and the cooling efficiency of the inverter section also decreases relatively. Therefore, under the condition of the low speed, the overheating of the inverter section may further increase.

[0070] The inverter section temperature determination step (ST220) described above corresponds to either the inverter section temperature being higher than the outside air temperature or remaining at or above a first temperature. For example, this corresponds to the case where the first temperature is 80 degrees Celsius or higher. When the inverter section temperature rises due to self-heating, this temperature is determined to be the temperature at which an overheating state has occurred.

[0071] In addition, by accepting inputs of the inverter unit temperature and the outside air temperature, and using information to more accurately determine whether there is overheating based on the inverter unit temperature, the electric compressor can be accurately judged in terms of its status and can be used as logic to protect the electric compressor in case of abnormal operation.

[0072] The phase current determination step (ST230) described above corresponds to the case where the phase current remains at or above the first current value. For example, this corresponds to the case where the first current value remains at or above 33A. The phase current is the current applied to the three phases U, V, and W to generate the torque required for the operation of the electric compressor. When the phase current remains at or above 33A, it is determined that the inverter section is overheating.

[0073] In this embodiment, when the current speed per minute of the electric compressor is equivalent to a low speed, the temperature of the inverter section remains within the overheating temperature range, and the phase current remains above a certain value, it can be determined that the inverter section is overheating, thereby improving both accuracy and stability.

[0074] As described above, when the electric compressor meets the above-mentioned state conditions under overload pressure conditions and is thus judged to be in an overheated state (ST300), the high temperature error signal is turned on (On) and the electric compressor is switched to a state of temporary shutdown (ST310).

[0075] When the inverter unit continues to operate under overheated conditions, damage caused by malfunctions and damage to inverter components will occur. Therefore, along with the high temperature error signal, the electric compressor stops working and switches to a temporary stop state, thereby prioritizing the prevention of damage caused by overheating of the inverter unit.

[0076] The third step (ST300) mentioned above also includes a high-temperature error standby step (ST320), which maintains the standby state during the first time period after a high-temperature error code is generated.

[0077] Regarding the aforementioned high-temperature error standby step (ST320), as an example, the standby state is maintained for 15 seconds, during which the operation of the electric compressor is stopped, and this is maintained 3 times.

[0078] Furthermore, in step 4 (ST400), the discharge pressure of the current electric compressor is reconfirmed (ST410) after the first time mentioned above, thereby confirming whether it can be restarted.

[0079] If the discharge pressure of the electric compressor is above 275 psi, then go back to the point before reconfirming the discharge pressure of the electric compressor (ST410) and re-evaluate the discharge pressure (ST420).

[0080] As an example, there are also cases where the discharge pressure of the electric compressor temporarily increases and then decreases, so the discharge pressure needs to be reconfirmed.

[0081] In this embodiment, if the result of reconfirming the output pressure as described above (ST420) is that the output pressure is still above 275 psi, the vehicle power supply is forcibly disconnected (Off) to prevent damage to the inverter components caused by overheating of the inverter section (ST430).

[0082] When the vehicle power is disconnected as described above, the electric compressor stops working, thereby isolating the inverter section from an environment that may overheat. This can prevent damage caused by damage to inverter components in advance and provide stable protection for the high-performance electric compressor.

[0083] After the compressor stops working, the air conditioner stops working, so it can be repaired after the vehicle is moved to a repair shop.

[0084] In this embodiment, when the discharge pressure is below 275 psi, switching to the step of restarting the electric compressor (ST500) enables the air conditioner to operate, thereby enabling cooling of the vehicle's interior area.

[0085] Furthermore, after the electric compressor is restarted, the discharge pressure is checked again as in step 1 (ST100) to determine whether it is equivalent to overload pressure.

[0086] A control method for an electric compressor based on another embodiment of the present invention will be described with reference to the accompanying drawings.

[0087] Reference Figure 3This embodiment includes: a first step (ST1000), which includes determining the current discharge pressure state of the electric compressor when the air conditioning in the vehicle is on; a second step (ST2000), which, when the discharge pressure is equivalent to overload pressure, simultaneously determines the current speed per minute of the electric compressor, the temperature information of the inverter section, the phase current information, the temperature rise rate of the inverter section, and the cumulative time information; a third step (ST3000), which, when the inverter section is in an overheated state, maintains the high temperature error signal on; and a fourth step (ST4000), which, after the high temperature error signal is on, determines whether the electric compressor is working based on the discharge pressure of the inverter section.

[0088] Step 1 (ST1000) is similar to the first embodiment (ST100) described above, so detailed descriptions are omitted. Step 2 (ST2000) will be described instead. The difference in Step 2 (ST2000) is that it includes: a speed-per-minute determination step (ST2100) to determine the current speed-per-minute status of the electric compressor; an inverter section temperature determination step (ST2200) to determine whether the temperature of the inverter section is within a set overheating temperature range; and a phase current determination step (ST2300) to determine whether the phase current of the electric compressor remains above a certain value. Furthermore, the temperature rise rate and accumulation time of the inverter section are simultaneously determined (ST2400) to assess whether overheating of the inverter section exists. Therefore, it is possible to more accurately determine the potential damage risk caused by a rapid temperature rise in the inverter section.

[0089] The aforementioned speed per minute determination step (ST2100) is equivalent to the electric compressor operating at a speed of less than 1000 RPM. The aforementioned 1000 RPM refers to the low-speed operation when the vehicle is stationary, which is equivalent to the operation under high temperature and high pressure conditions inside the electric compressor.

[0090] When the electric compressor operates at a speed of 1000 RPM, the refrigerant circulation is reduced compared to normal conditions, and the cooling efficiency of the inverter section is also relatively reduced. Therefore, under the condition of the low speed, the overheating of the inverter section may further increase.

[0091] The inverter section temperature determination step (ST2200) described above can be equivalent to either the inverter section temperature being higher than the outside air temperature or maintaining a first temperature or higher, where the first temperature is equivalent to maintaining a temperature of 80 degrees or higher. When the inverter section temperature rises due to self-heating, the temperature is determined to be the temperature at which an overheating state has been entered.

[0092] In addition, the inverter temperature and outside air temperature are received as inputs to more accurately determine whether there is overheating based on the inverter temperature. This allows for accurate determination of the electric compressor's status and enables the use of logic to protect the electric compressor during abnormal operation.

[0093] The phase current determination step (ST2300) described above corresponds to the case where the phase current is maintained at or above the first current value. For example, this corresponds to the case where the first current value is maintained at or above 33A. The phase current is the current applied to the three phases U, V, and W to generate the torque required for the electric compressor to operate. When the phase current is maintained at or above 33A, it is determined that the inverter section is overheating.

[0094] This embodiment is equivalent to the situation where the current speed per minute of the electric compressor is low. The temperature of the inverter section is maintained within the overheating temperature range. At the same time, it determines whether the phase current is maintained above a certain value, the temperature rise rate of the inverter section, and the cumulative time to determine whether the inverter section is overheating. Therefore, it improves both accuracy and stability.

[0095] Regarding the temperature rise rate and accumulation time of the inverter section mentioned above, when the temperature rise rate and accumulation time of the inverter section are equivalent to... Figure 4 When the casings 1 to 3 are shown, it can be determined that the inverter section has entered an overheated state.

[0096] As an example, even in the case of housing 1, if the cumulative time is less than the time shown in the attached figure, or the temperature of the inverter section is less than 120 degrees, the inverter section is judged to be in a pre-overheating state.

[0097] As described above, by adding information on the rate of temperature rise and cumulative time to determine whether the inverter section is overheating, together with the discharge pressure information of the electric compressor, it is possible to accurately determine whether there is normal or abnormal operation, thereby enabling immediate control and minimizing the occurrence of the aforementioned electric compressor malfunctions.

[0098] The electric compressor based on this embodiment will be described with reference to the accompanying drawings.

[0099] Reference Figures 5 to 6The system includes: a compression unit 3, which is provided with a compressor for compressing refrigerant; a motor unit 2, which is attached to one side of the compression unit 3 and is provided with a motor that provides driving force to the compressor; an inverter unit 1, which is attached to one side of the motor unit 2 and is provided with an inverter for controlling the motor unit 2; a detection unit 4, which detects the discharge pressure of the compression unit 3, the rotational speed per minute, the temperature of the inverter unit 1, the phase current applied to the compression unit 3, and the rate of temperature rise of the inverter unit 1; and a control unit 5, which receives the information detected in the detection unit 4 and determines the overheating state of the inverter unit 1.

[0100] Along with the information detected in the detection unit 4, the control unit 5 also receives input indicating whether the cooling fan in the vehicle is working in order to determine whether the inverter unit 1 is overheating.

[0101] The aforementioned detection unit 4 includes: a first detection unit 4a, which detects the discharge pressure of the compression unit 3; a second detection unit 4b, which detects the rotational speed per minute of the compression unit 3; a third detection unit 4c, which detects the temperature of the inverter unit 1; a fourth detection unit 4d, which detects the phase current applied to the compression unit 3; and a fifth detection unit 4e, which detects the rate of temperature rise of the inverter unit 1.

[0102] Along with the control of the motor unit 2, the control unit 5 receives input from the information detected by the first to fifth detection units 4a, 4b, 4c, 4d, and 4e to accurately determine whether the inverter unit 1 is overheating, thereby preventing the electric compressor from malfunctioning.

[0103] The control unit 5 compares the data preset when the electric compressor is working under normal conditions with the information input through the detection unit 4 to accurately determine whether the inverter unit 1 is overheating.

[0104] While an embodiment of the present invention has been described above, those skilled in the art can make various modifications and alterations to the present invention by adding, changing, deleting, or adding constituent elements without departing from the spirit of the present invention as stated in the claims, and these modifications and alterations should also be included within the scope of the claims of the present invention.

[0105] Industrial availability

[0106] This embodiment can prevent overheating of the inverter section and ensure stable operation of the electric compressor.

Claims

1. A control method for an electric compressor, comprising: Step 1 includes determining the current discharge pressure of the electric compressor when the vehicle's air conditioning is on. Step 2: When the discharge pressure is equivalent to the overload pressure, the current speed per minute of the electric compressor, the temperature information of the inverter section, and the phase current information are judged. Step 3: When the inverter section is in an overheated state, maintain the high temperature error signal on. as well as Step 4: After the high temperature error signal is activated, determine whether the electric compressor is working based on the discharge pressure of the electric compressor.

2. The control method for the electric compressor according to claim 1, wherein, The first step also includes a cooling fan operation confirmation step, which confirms whether the cooling fan installed in the vehicle is working.

3. The control method for the electric compressor according to claim 1, wherein, The first step also includes an inverter section temperature detection step, which detects the current temperature of the inverter section when the output pressure is below the overload pressure.

4. The control method for the electric compressor according to claim 1, wherein, The second step includes: The step of determining the rotational speed per minute is to determine the current rotational speed of the electric compressor per minute. The inverter section temperature determination step determines whether the temperature of the inverter section is within a pre-set overheating temperature range; and The phase current determination step determines whether the phase current of the electric compressor is maintained above a certain value.

5. The control method for the electric compressor according to claim 4, wherein, The step of determining the rotational speed per minute is equivalent to the case where the electric compressor is operating at a speed of less than 1000 RPM.

6. The control method for the electric compressor according to claim 4, wherein, The inverter temperature determination step is equivalent to either the inverter temperature being higher than the outside air temperature or maintaining a temperature above a first temperature.

7. The control method for the electric compressor according to claim 4, wherein, The phase current determination step is equivalent to the case where the phase current is maintained above the first current value.

8. The control method for the electric compressor according to claim 4, wherein, The second step is equivalent to the current speed of the electric compressor being low. When the temperature of the inverter section remains within the overheating temperature range and the phase current remains above a certain value, it is determined that the inverter section is in an overheating state.

9. The control method for the electric compressor according to claim 1, wherein, The third step also includes a step of switching to a state where the high temperature error signal is activated while the operation of the electric compressor is temporarily stopped.

10. The control method for the electric compressor according to claim 9, wherein, The third step also includes a high-temperature error standby step, which maintains the standby state during the first time period after a high-temperature error code is generated.

11. The control method for the electric compressor according to claim 10, wherein, After the third step, the fourth step further includes a discharge pressure reconfirmation step, in which the discharge pressure is reconfirmed after the first time.

12. The control method for an electric compressor according to claim 11, wherein, In step 4, if the discharge pressure continues to be maintained above the predetermined pressure after the discharge pressure reconfirmation is achieved, the process moves to before the discharge pressure reconfirmation step.

13. The control method for an electric compressor according to claim 12, wherein, The fourth step includes the following steps: after moving to the discharge pressure reconfirmation step, when the discharge pressure continues to maintain a predetermined pressure, the vehicle power is switched to a state of disconnection.

14. The control method for an electric compressor according to claim 11, wherein, The fourth step further includes the following step: restarting the electric compressor when the pressure is below the predetermined pressure in the discharge pressure reconfirmation step.

15. The control method for an electric compressor according to claim 14, wherein, After the electric compressor restarts, proceed to step 1 to reconfirm the discharge pressure status.

16. A control method for an electric compressor, comprising: Step 1 includes determining the current discharge pressure of the electric compressor when the vehicle's air conditioning is on. Step 2: When the discharge pressure is equivalent to the overload pressure, simultaneously determine the current speed per minute of the electric compressor, the temperature information of the inverter section, the phase current information, the temperature rise rate of the inverter section, and the cumulative time information. Step 3: When the inverter section becomes overheated, maintain the high temperature error signal on. as well as Step 4: After the high temperature error signal is activated, determine whether the electric compressor is working based on the discharge pressure of the electric compressor.

17. An electric compressor, comprising: The compression section is equipped with a compression device for compressing the refrigerant; The motor section, which is attached to one side of the compression section, is provided with a motor that provides driving force to the compression device; The inverter section is attached to one side of the motor section and has an inverter for controlling the motor section. The detection unit detects the discharge pressure of the compression unit, the rotational speed per minute, the temperature of the inverter unit, the phase current applied to the compression unit, and the temperature rise rate of the inverter unit. as well as The control unit receives input from the information detected by the detection unit and determines the overheating state of the inverter unit. The electric compressor is controlled by the control method of the electric compressor according to any one of claims 1 to 16.

18. The electric compressor according to claim 17, wherein, The control unit, together with the information detected in the detection unit, simultaneously receives information about whether the cooling fan installed in the vehicle is operating, and determines whether the inverter unit is overheating.

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