JP2015149270A - Cooling water state-determining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling water state-determining method capable of determining whether or not cooling water is in a state of shortage and whether or not cooling water circulation is abnormal.SOLUTION: A cooling water state-determining method includes following steps of: operating a pump driving motor for circulating cooling water at a fixed current, a fixed torque, or a fixed output; calculating an average rotational speed for a predetermined time period of the motor during the operation; and determining normal circulation of the cooling water on the basis of an error between the calculated average rotational speed and a predetermined reference rotational speed.

Description

  The present invention relates to a cooling water state determination method, and more particularly, to a cooling water state determination method by analyzing torque, output, and rotation speed of a cooling water circulation pump.

  A fuel cell system mounted on a fuel cell vehicle includes a hydrogen supply system that supplies hydrogen to the fuel cell stack, and an air supply system that supplies oxygen in the air, which is an oxidant necessary for an electrochemical reaction, to the fuel cell stack. A fuel cell stack that generates electricity through an electrochemical reaction of hydrogen and oxygen, and a heat and water management system that removes the electrochemical reaction heat of the fuel cell stack and controls the operating temperature of the stack.

  However, the heat and water management system described above filters a pump that circulates cooling water to the fuel cell stack, a radiator that cools the cooling water discharged from the fuel cell stack, and ions that are eluted from the cooling loop. Includes ion filter. An atmospheric pressure cap is attached to the upper end of the radiator of such a heat and water management system, the reservoir is provided with an open-air structure, and a water level sensor is attached inside. In order to install the cooling water level sensor in the reservoir, a predetermined package space is required, and it is difficult to secure the package space. Even if the water level sensor is installed, water and air are mixed in the cooling water. In the case of circulation, the water level sensor cannot detect that the cooling water has been lost, and has a problem of recognizing the normal level. (For example, refer to Patent Document 1.)

  In other words, the cooling water shortage phenomenon has already been judged by the water level sensor or the pressure sensor installed in the pipe. However, this method is a disturbance, that is, the temperature change of the cooling water, the change of the cooling loop due to the opening and closing of the cooling line valve, Or the detection value is often misdetected by the influence of the vibration of the equipment.

  In order to improve this, a flow sensor may be attached to the cooling water pipe, but the price of the sensor becomes high, and there is a problem that it is not easy to attach due to inconvenience such as installation of a separate pipe for attaching the sensor. .

Korean Application Publication No. 10-2013-0124789A Specification

  The present invention has been made in view of the above points, and an object of the present invention is to provide a cooling water state determination method capable of determining whether or not cooling water shortage and cooling water circulation are abnormal. With the goal.

  In order to achieve such an object, a cooling water state determination method according to an embodiment of the present invention includes operating a pump driving motor for circulating cooling water at a fixed current, a fixed torque, or a fixed output, A step of calculating an average rotation speed during a preset time of the motor, and a step of determining normal circulation of the cooling water based on an error between the calculated average rotation speed and a preset reference rotation speed , Including.

  The step of calculating the average rotational speed further includes a step of calculating a rotational speed deviation during the preset time.

  The step of determining normal circulation of the cooling water is a step of determining normal circulation of the cooling water by comparing a magnitude of the calculated rotational speed deviation and a preset reference deviation. .

  The preset reference rotational speed is a rotational speed of the motor corresponding to the fixed current, fixed torque, or fixed output.

  According to another embodiment of the present invention, there is provided a cooling water state determination method of maintaining a rotation speed of a pump driving motor for circulating cooling water at a constant level, and maintaining the rotation speed at a constant level. Determining a normal circulation of the cooling water using a reference output or torque value in a normal state corresponding to the output or torque value and the maintained rotation speed.

  When rotating at the motor output or torque value and the rotation speed, the output or torque value is confirmed using the current command value to the motor and the current command value in the normal state corresponding to the maintained rotation speed, respectively. It is characterized by that.

  The step of determining the normal circulation of the cooling water is a step of calculating an average value of current command values to the motor during a preset time after maintaining the rotation speed constant, and the calculated average value And determining a normal circulation of the cooling water based on an error between a normal current command value corresponding to the maintained rotation speed.

  The method further includes the step of normalizing by dividing the calculated average value by a current command value in a normal state corresponding to the maintained rotation speed.

  When the state where the error exceeds the preset error reference value continues for a preset time, it is determined that the cooling water is in an abnormal circulation state.

  The method may further include enabling a test mode when the error exceeds a preset error reference value.

  When the state in which the error between the average value calculated in the test mode and the current command value during rotation at the maximum rotation speed exceeds the preset error reference value continues for the preset time, the cooling water It is characterized in that it is in an abnormal circulation state.

  The error reference value is changed according to the rotation speed of the motor.

  When the test mode is enabled, the motor is maintained at a maximum rotation speed.

  The current command value corresponding to the rotation speed is obtained from a current command map already set according to the rotation speed.

  The step of determining normal circulation of the cooling water calculates a deviation or variance value of a current command value during the preset time, and compares the calculated deviation or variance value with a preset reference value. And determining a normal circulation of the cooling water based on the determination.

  When the calculated deviation or variance value exceeds a preset reference value and continues for a preset time, it is determined that the cooling water is in an abnormal circulation state.

  The method further includes enabling a test mode when the calculated deviation or variance exceeds a preset reference value.

  When the test mode is enabled, the motor is maintained at a maximum rotation speed.

  The step of determining normal circulation of the cooling water integrates an error between a current command value corresponding to the rotation speed and a current command value to the motor, and is based on a comparison result between the integrated value and a preset reference value. And determining the normal circulation of the cooling water.

  The method further includes the step of normalizing by dividing the calculated average value by a current command value in a normal state corresponding to the rotation speed.

  When the integral value exceeds a preset reference value and continues for a preset time, it is determined that the cooling water is in an abnormal circulation state.

  The method may further include enabling a test mode when the integral value exceeds a preset reference value.

  When the test mode is enabled, the motor is maintained at a maximum rotation speed.

  According to another embodiment of the present invention, there is provided a cooling water state determination method of maintaining a rotation speed of a pump driving motor for circulating cooling water at a constant level, and maintaining the rotation speed at a constant level. And enabling a test mode when an error occurs between the output or torque value and the reference output or torque value in a normal state corresponding to the maintained rotation speed.

  In the test mode, normal circulation of the cooling water is determined with the motor maintained at a maximum rotation speed.

It is a graph which shows the relationship between the rotational speed of a cooling water motor, and the pressure difference of a cooling water pump inlet / outlet end. It is a graph which shows the relationship between the rotational speed of a cooling water motor, and the cooling water flow rate of a cooling water pump inlet / outlet end. It is a graph which shows the relationship between the rotational speed of a cooling water motor, and the output or torque of a motor. 6 is a graph illustrating motor speeds in a normal state and an abnormal state when a cooling water motor is operated at a fixed current in a cooling water state determination method according to an embodiment of the present invention. 6 is a graph illustrating an average value of the output or torque of a cooling water motor according to a cooling water circulation state in the cooling water state determination method according to an embodiment of the present invention. It is a flowchart which shows the cooling water state judgment method by one Example of this invention. It is a flowchart which shows the cooling water state determination method by the other Example of this invention. It is a flowchart which shows the cooling water state determination method by the other Example of this invention. It is a flowchart which shows the cooling water state determination method by the other Example of this invention. It is a flowchart which similarly shows the cooling water state determination method by another Example. It is a flowchart which similarly shows the cooling water state determination method by another Example. It is a flowchart which similarly shows the cooling water state determination method by another Example.

  The specific structural or functional descriptions of the embodiments of the present invention disclosed in this specification or the application are merely illustrative for the purpose of illustrating the embodiments of the present invention, and The examples may be implemented in a variety of forms and should not be construed as limited to the examples set forth in this specification or application.

  While embodiments according to the present invention may be modified in various ways and may have a variety of forms, specific embodiments are illustrated in the drawings and will be described in detail herein. However, this is not to limit the embodiments according to the concept of the present invention to a specific form of disclosure, but to be understood to include all modifications, equivalents or alternatives that fall within the spirit and scope of the present invention. There must be.

  Terms such as first and / or second can be used to describe various components, but such components should not be limited to the terms. The term is used for the purpose of distinguishing one component from other components. For example, the first component may be named as the second component within a scope that does not depart from the scope of rights according to the concept of the present invention. Similarly, the second component can be named the first component.

  When a component is referred to as being “connected” or “connected” to another component, it may be directly connected to or connected to another component, It should be understood that other components may exist. On the other hand, when a component is referred to as being “directly connected” or “directly connected” to another component, it must be understood that there are no other components in between. Other expressions describing the relationship between the components, such as “between” and “immediately between” or “adjacent to” and “adjacent to” must be interpreted in the same way.

  The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. A single expression includes the plural unless the context clearly dictates otherwise. In this specification, terms such as “including” or “having” are intended to indicate that the indicated feature, number, step, action, component, part, or combination thereof is present. It should be understood that the possibility of existence or addition of one or more other features or numbers, steps, actions, components, components or combinations thereof is not excluded in advance.

  Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. is there. Commonly used terms, such as those that are predefined, must be construed to have a meaning consistent with the meaning in the context of the related art, and are ideally or excessively defined unless explicitly defined in this specification. Do not interpret it in a formal sense.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. The same reference numerals in the drawings indicate the same members.
In addition, the pump driving motor, the cooling water motor, the cooling water pump motor, and the motor for circulating the cooling water in the sentence all refer to the same thing.

  1 to 3 are graphs showing the relationship between the pressure difference at the inlet / outlet end of the coolant pump, the coolant flow rate, and the motor output or torque depending on the rotational speed of the coolant motor.

  1 to 3, when the cooling water circulates normally without a shortage in the cooling system, the pressure difference between the inlet and outlet ends of the cooling water pump and the flow rate of the cooling water are normal values. The torque required to drive the cooling water pump at a constant speed also appears within a certain range of normal state values. However, if the cooling water cannot circulate normally, the cooling water flow rate and pressure difference will be outside the normal range, and the motor torque or output will also be outside the normal state range. The cooling pump operating speed also vibrates without following the speed command value.

  FIG. 4 is a graph showing motor speeds in a normal state and an abnormal state when the cooling water motor is operated at a fixed current in the cooling water state determination method according to an embodiment of the present invention.

  Referring to FIG. 4, when the cooling water motor is operated at a fixed current and the output or torque of the motor is constant over time, the rotation speed of the motor is constant when the cooling water circulation state is normal. In some cases, that is, when the cooling water is insufficient, when the cooling water leaks, or when the piping is clogged, the load fluctuates and the rotation speed of the motor vibrates.

  Specifically, when the output or torque of the motor is constant over time and the cooling circulation state is abnormal and the cooling water is small and short, the cooling water pump (motor ) Is reduced, the average rotational speed is increased as compared with the normal state, and when the bubbles flow into the pump, the rotational speed vibrates due to a rapid load fluctuation.

  In addition, when the cooling water is insufficient due to leakage of cooling water, bubbles are continuously flowing into the pump and the rotation speed continuously oscillates or water cannot be discharged. It rotates much faster than the rotation speed.

  When foreign matter circulates in the cooling water pipe, the load of the cooling water pump may change and vibration of the rotation speed may occur, as in the case where bubbles flow in. In addition, when the cooling water pipe is clogged due to foreign matter or physical damage, the load is rapidly reduced and the rotation speed of the cooling water pump is greatly increased compared to the normal state.

  FIG. 5 is a graph showing an average value of the output or torque of the cooling water motor according to the cooling water circulation state in the cooling water state determination method according to one embodiment of the present invention.

  Referring to FIG. 5, FIG. 5 shows data comparing the motor output or torque when the coolant flow rate is normal and when the coolant flow rate is insufficient in the vehicle. However, if the coolant flow rate is insufficient, the motor output or torque will vibrate. FIG. 5 shows the average value of the motor output or torque. As the cooling water flow rate becomes insufficient, the average value of the motor output decreases and the deviation becomes severe.

  Motor output or torque can be obtained by measuring DC single current and voltage, measuring three-phase current and voltage, measuring using a torque sensor, and speed and input after three-phase current measurement. There is a method of using a preset torque map by voltage change. Since the current command has a proportional relationship with the motor torque, the torque can be calculated based on the current command and the three-phase current measurement value (vector sum of the three-phase current) confirmed by the current sensor.

FIG. 6 is a flowchart showing a cooling water state determination method according to an embodiment of the present invention.
First, a cooling water pump, that is, a cooling water motor is operated with a fixed current (S401). In a state where the cooling water motor is operated with a fixed current, the average rotation speed (Rpm_mean) or rotation speed deviation (Delta_Rpm) of the cooling water motor during the preset time (T1) is calculated (S403). After a predetermined time (Time1 + ΔT) has elapsed (S405), it is determined whether a predetermined time (Time1) longer than the preset time (T1) has elapsed (S407). This is for judging the cooling water state after normally calculating the average rotation speed and speed deviation during the preset time (T1).

If it is confirmed that the preset time (T1) has elapsed, it is determined whether or not the motor rotation speed is normal compared to the preset reference rotation speed (S411). The preset reference rotational speed can be obtained by setting the fixed current to the preset value when the motor is operating at a fixed current, whereby the rotational speed of the normal state cooling water pump at the fixed current (Rpm_Normal) ) Is calculated (S409).
Based on the error between the calculated average rotational speed (Rpm_mean) and the normal state rotational speed (Rpm_Normal) at a fixed current, or the rotational speed deviation (Delta_Rpm) between the preset time (T1) and the preset reference Based on the difference from the magnitude of the deviation (ε), it is determined whether or not the rotation speed of the cooling water motor is normal.

  Specifically, when determining whether or not the cooling water is normally circulated, an error between the calculated average rotational speed (Rpm_mean) and a normal state rotational speed (Rpm_Normal) at a fixed current is an error criterion that has been set. If the rotation speed deviation (Delta_Rpm) during the preset time (T1) is greater than the preset reference deviation (ε) during the preset time (T2) S413, S415), it can be determined that the cooling water is in an abnormal circulation state.

  If the preset time (T1, T2) has not elapsed, or the error between the calculated average rotational speed (Rpm_mean) and the normal state rotational speed (Rpm_Normal) at a fixed current is the preset error reference value (β) If it is smaller, or if the rotational speed deviation (Delta_Rpm) during the preset time (T1) is smaller than the preset reference deviation (ε), the process returns to the logic start stage again. Thereafter, the operation of operating the cooling water motor with a fixed current (S401) is repeatedly performed.

  When calculating the rotational speed deviation (Delta_Rpm) during the preset time (T1), the dispersion of the rotational speed during the preset time, the standard deviation, the average of the absolute error, and the like can be used. Further, it is possible to determine the normal circulation of the cooling water using both the average rotation speed and the rotation speed deviation, or using only one of them.

  7 to 9 are flowcharts showing a cooling water state determination method according to another embodiment of the present invention.

  7 to 9, first, it is confirmed whether or not the speed command has changed (S501, S601, S701). The speed command is a control command value for the rotational speed of the motor, and the reason for confirming the change of the speed command is that when the speed command is changed, the current command value changes in order to increase or decrease the speed. In order to increase the accuracy of the determination of the current command value, the cooling water state determination logic is advanced after maintaining the rotation speed constant.

  After maintaining the rotation speed constant, normal circulation of the cooling water is determined using a current command value to the cooling water motor for a preset time and a current command value corresponding to the rotation speed maintained constant.

  Specifically, referring to FIG. 7, after maintaining the rotation speed of the motor constant, an average value ((Iqmd) of the current command value (Iqcmd) to the cooling water motor during the preset time (T1). mean) is calculated (S505). Whether or not the average value of the current command value during the preset time (T1) has been normally calculated is the first elapsed time (Time1) after the predetermined time (ΔT) has passed with respect to the first elapsed time. Confirmation is made by comparison with the preset time (T1) (S507, S509). If the first elapsed time is less than the preset time, the rotation speed of the motor is further controlled to be constant (S501).

  On the other hand, when the rotation speed of the motor is not maintained constant, the first elapsed time is reset (S503), and the rotation speed is further maintained constant (S501).

  After the rotation speed is kept constant, a current command value (Iqnormal) corresponding to the maintenance rotation speed is calculated (S511). The current command value (Iqnormal) corresponding to the rotation speed can be obtained from a current command map based on the rotation speed. The current command value (Iqnormal) corresponding to the rotation speed is a current command value when the cooling water pump rotation speed is normal. The current command map is a map in which normal current command values are mapped in accordance with the rotation speed secured by test data or calculation results when the cooling water pump normally circulates.

  When the state (S513) where the error between the calculated average value and the normal current command value corresponding to the rotation speed is equal to or greater than the preset error reference value (β) continues for the preset time (T2) (S517, S519), it can be determined that the cooling water is in an abnormal circulation state. On the other hand, if the error between the calculated average value and the normal current command value corresponding to the rotational speed is less than the preset error reference value (β), the preset time (T2) is reset and further constant at the new rotational speed. Repeat the process of maintaining.

  On the other hand, when the current command value (Iqcmd) Nom is used by dividing the current command value (Iqcmd) by the normal current value (Iqnormal) at the current rotational speed, the speed command value is continuously changed. It is possible to determine the normal circulation of the cooling water even in the section where the rotation speed is changed.

  Referring to FIG. 8, after maintaining the rotation speed of the motor constant, a deviation ((Iqcmd) sd) or a variance value of the current command value (Iqcmd) during the preset time (T1) is calculated (S605). ). It is determined whether or not the deviation ((Iqcmd) sd) or variance value during the preset time (T1) is obtained accurately (S607, S609), and the calculated deviation ((Iqcmd) sd) or variance value and Compared with the preset reference value (ε) (S611), and the calculated deviation ((Iqcmd) sd) or variance exceeds the preset reference value (ε) and continues for the preset time (T2) If so (S615, S617), it can be determined that the cooling water is in an abnormal circulation state. The parts described above in FIG. 7 are omitted. The difference from the method shown in FIG. 7 is that the standard deviation is calculated instead of the average value.

  Referring to FIG. 9, after maintaining the motor rotation speed constant, a normal state current command value (Iqnormal) at the rotation speed maintained constant is calculated (S705). The absolute value of the error between the current command value (Iqcmd) to the cooling water motor and the normal state current command value (Iqnormal) during the preset time (T1) is integrated (S707). It is determined whether or not the integral value during the preset time (T1) has been accurately obtained (S709, S711), and the integral value during the preset time (T1) and the preset reference for the absolute value of the error When the integrated value exceeds the preset reference value (k) and continues for the preset time (T2) (S717, S719), the cooling water is abnormally circulated. It can be judged that it is in a state.

  On the other hand, when the current command value ((Iqcmd) Nom) normalized by dividing the current command value (Iqcmd) by the normal current value (Iqnormal) at the current rotation speed is used, the speed command value is continuously changed and the rotation speed is changed. It is possible to determine the normal circulation of the cooling water even in a section in which is changed.

  10 to 12 are flowcharts illustrating a cooling water state determination method according to an embodiment of the present invention.

  10 to 12 are the same as S501 to S511 of FIG. 7, S601 to S609 of FIG. 8, and S701 to S711 of FIG. .

  Referring to FIG. 10, the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotation speed and the preset error reference value (β) are large. The absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotational speed is the preset error reference value (β). If it exceeds, it is determined whether or not the test mode state (Test flag = TRUE) (S815). On the other hand, when the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotation speed is equal to or less than the preset error reference value (β), the test mode is entered. No conversion is performed (S817, Test flag = FALSE), and a constant speed command is maintained (S801).

  If it is determined in the determination step (S815) that the test mode is not currently set, the test mode is set (Test flag = TRUE), and the motor of the cooling water pump is driven at the maximum rotational speed (S823). This is because the current error can be more accurately determined when the motor of the cooling water pump is driven at the maximum rotational speed. In other words, the output error appears the largest when an abnormality occurs in the cooling water circulation at the maximum rotation speed, and it can be set to a speed at which the abnormality of the cooling water circulation can be determined most easily experimentally. In addition to the maximum rotational speed drive, the current error can be determined by repeated driving of the maximum rotational speed and the minimum rotational speed, ramp acceleration / deceleration, step acceleration / deceleration driving, and the like.

  When the test mode is set and the cooling water pump motor is driven at a constant maximum rotation speed, an average value of current command values (Iqcmd) to the cooling water motor during a preset time (T1) ( (Iqmd) mean) is calculated (S805). Whether or not the average value of the current command value during the preset time (T1) has been normally calculated is determined with respect to the first elapsed time (Time 1) after the predetermined time (ΔT) has elapsed with respect to the first elapsed time. Confirmation is made by comparison with the set time (T1) (S807, S809). If the first elapsed time is less than the preset time, the rotation speed of the motor is further controlled to be constant (S801). On the other hand, if the rotation speed of the motor is not maintained constant, the first elapsed time is reset (S803), and further the rotation speed is maintained constant (S801).

  Thereafter, a current command value (Iqnormal) corresponding to the maximum rotation speed is calculated (S811). The current command value (Iqnormal) corresponding to the rotation speed can be obtained from a current command map based on the rotation speed. The current command value (Iqnormal) corresponding to the rotation speed is a current command value when the cooling water pump rotation speed is normal. The current command map is a map in which normal current command values are mapped in accordance with the rotation speed secured from the test data or calculation results when the cooling water pump normally circulates.

  Further, the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotation speed is compared with the magnitude of the preset error reference value (β) ( S813), when the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotation speed exceeds the preset error reference value (β) It is determined whether or not the state is (Test flag = TRUE) (S815). Since the test mode is set in the previous step S823, the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotation speed is the preset error criterion. It is determined whether or not the state exceeding the value (β) continues for the preset time (T2) or longer, and the error between the calculated average value and the normal current command value corresponding to the rotation speed is the preset error criterion. When the state exceeding the value (β) continues for the preset time (T2) (S819, S821), it can be determined that the cooling water is in an abnormal circulation state.

  Referring to FIG. 11, the method shown in FIG. 11 is compared with the method shown in FIG. 10, and the standard deviation is calculated instead of calculating the average value of the current command value during the preset time (T1). There is a difference. Therefore, it is not whether or not the absolute value of the error between the calculated average value ((Iqcmd) mean) and the normal current command value (Iqnormal) corresponding to the rotational speed exceeds the preset error reference value (β). There is a difference in determining whether or not to enter the test mode depending on whether or not the calculated standard deviation ((Iqcmd) sd) exceeds a preset deviation value (ε).

  If the calculated standard deviation exceeds the preset deviation value (ε), it is determined whether or not the test mode state (Test flag = TRUE) (S913). On the other hand, when the calculated standard deviation is equal to or smaller than the preset deviation value (ε), the test mode is not switched (S915, Test flag = FALSE), and a constant speed command is maintained (S901).

  If it is determined in the determination step (S913) that the test mode is not currently set, the test mode is set (Test flag = TRUE), and the motor of the cooling water pump is driven at the maximum rotational speed (S921). This is because the current error can be determined more accurately when the motor of the cooling water pump is driven at the maximum rotational speed. In other words, the output error appears the largest when an abnormality occurs in the cooling water circulation at the maximum rotation speed, and it can be set to a speed at which the abnormality of the cooling water circulation can be determined most easily experimentally. In addition to the maximum rotational speed drive, the current error can be determined by repeatedly driving the maximum rotational speed and the minimum rotational speed, ramp acceleration / deceleration, step acceleration / deceleration driving, and the like.

  When the test mode is set and the cooling water pump motor is driven at a constant maximum rotational speed, the standard deviation of the current command value (Iqcmd) to the cooling water motor during the preset time (T1) ( (Iqcmd) sd) is calculated (S905). Whether or not the standard deviation ((Iqcmd) sd) of the current command value during the preset time (T1) has been normally calculated is determined after a predetermined time (ΔT) has elapsed with respect to the first elapsed time. Confirmation is made by comparing one elapsed time (Time1) and a preset time (T1) (S907, S909). If the first elapsed time is less than the preset time, the rotation speed of the motor is further controlled to be constant (S901). On the other hand, if the rotation speed of the motor is not maintained constant, the first elapsed time is reset (S903), and the rotation speed is further maintained constant (S901).

  Thereafter, the calculated standard deviation is compared with the preset deviation value (ε) (S911), and when the calculated standard deviation exceeds the preset deviation value (ε), the test mode state (Test flag = TRUE) It is determined whether or not (S913). Since the test mode is set in the previous step S921, when the calculated standard deviation exceeds the preset deviation value (ε) for the preset time (T2) (S917, S919), the cooling water It can be determined that there is an abnormal circulation state.

  Referring to FIG. 12, the absolute value of the error between the current command value (Iqcmd) and the normal state current command value (Iqnormal) to the cooling water motor during the preset time (T1) is integrated, and this integrated value is obtained. And the preset reference value (k) are compared (S1013). When the integral value during the preset time (T1) with respect to the absolute value of the error exceeds the preset reference value (k), it is determined whether or not the test mode state (Test flag = TRUE) (S1015). . On the other hand, when the integral value of the absolute value of the error during the preset time (T1) is equal to or less than the preset reference value (k), the test mode is not switched (S1017, Test flag = FALSE) and is further constant. The speed command is maintained (S1001).

  If it is determined in the determination step (S1015) that the test mode is not currently set, the test mode is set (Test flag = TRUE), and the motor of the cooling water pump is driven at the maximum rotation speed (S1023). This is because the current error can be determined more accurately when the motor of the cooling water pump is driven at the maximum rotational speed. In other words, the output error appears the largest when an abnormality occurs in the cooling water circulation at the maximum rotation speed, and it can be set to a speed at which the abnormality of the cooling water circulation can be determined most easily experimentally. In addition to the maximum rotational speed drive, the current error can be determined by repeated driving of the maximum rotational speed and the minimum rotational speed, ramp acceleration / deceleration, step acceleration / deceleration driving, and the like.

  When the test mode is set and the cooling water pump motor is driven at a constant maximum rotation speed, a normal state current command value (Iqnormal) at the maximum rotation speed is further calculated (S1005), and the preset time ( The absolute value of the error between the current command value (Iqcmd) to the cooling water motor and the normal state current command value (Iqnormal) during T1) is integrated (S1007). Whether or not the integral value of the preset time (T1) has been normally calculated is determined after the predetermined time (ΔT) has passed with respect to the first elapsed time, the first elapsed time (Time1) and the preset time ( Confirmation is made by comparing T1) (S1009, S1011). If the first elapsed time is less than the preset time, the rotation speed of the motor is further controlled to be constant (S1001). On the other hand, if the maximum rotation speed of the motor is not maintained constant, the first elapsed time is reset (S803), and further maintained constant at the maximum rotation speed (S801).

  Further, the absolute value of the error between the current command value (Iqcmd) and the normal state current command value (Iqnormal) to the cooling water motor during the preset time (T1) is integrated, and this integrated value and the preset reference value are integrated. The magnitudes of (k) are compared (S1013). When the integral value during the preset time (T1) with respect to the absolute value of the error exceeds the preset reference value (k), it is determined whether or not the test mode state (Test flag = TRUE) (S1015). . Since the test mode was set in the previous step S1023, when the integral value exceeds the preset reference value (k) for more than the preset time (T2) (S1019, S1021), the cooling water is abnormally circulated. It can be judged that it is in a state.

  Although the present invention has been described with reference to one embodiment shown in the drawings, this is by way of example only, and various modifications and equivalent other embodiments can be made by those skilled in the art. You will understand that. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the claims.

  The present invention is applicable to the field of a cooling water state determination method that can determine whether or not cooling water shortage and cooling water circulation are abnormal.

Claims (25)

Operating a pump drive motor for circulating cooling water at a fixed current, fixed torque or fixed output;
Calculating an average rotational speed during a preset time of the motor during the operation; and
Determining a normal circulation of the cooling water based on an error between the calculated average rotation speed and a preset reference rotation speed. The step of calculating the average rotation speed includes:
The cooling water state determination method according to claim 1, further comprising a step of calculating a rotational speed deviation during the preset time. The step of determining normal circulation of the cooling water includes:
3. The cooling water state determination method according to claim 2, wherein the cooling water state determination method is a step of determining normal circulation of the cooling water by comparing magnitudes of the calculated rotational speed deviation and a preset reference deviation.   The cooling water state determination method according to claim 1, wherein the preset reference rotation speed is a rotation speed of the motor corresponding to the fixed current, fixed torque, or fixed output. Maintaining a constant rotation speed of a pump driving motor for circulating cooling water; and
Determining the normal circulation of the cooling water using the output or torque value of the motor and the reference output or torque value in a normal state corresponding to the maintained rotation speed after maintaining the rotation speed constant; A cooling water state determination method comprising:   The output or torque value of the motor and the output or torque value at the time of rotation at the rotation speed are confirmed using the current command value to the motor and the current command value in the normal state corresponding to the maintained rotation speed, respectively. The cooling water state determination method according to claim 5. The step of determining normal circulation of the cooling water includes:
Calculating an average value of a current command value to the motor for a preset time after maintaining the rotation speed constant; and
7. The method according to claim 6, further comprising: determining a normal circulation of the cooling water based on an error between the calculated average value and a current command value in a normal state corresponding to the maintained rotation speed. The cooling water state determination method described.   8. The cooling water state determination method according to claim 7, further comprising the step of normalizing the calculated average value by dividing by a normal current command value corresponding to the maintained rotation speed.   8. The cooling water state determination method according to claim 7, wherein when the state where the error exceeds a preset error reference value continues for a preset time, the cooling water is determined to be in an abnormal circulation state. .   The method of claim 7, further comprising enabling a test mode when the error exceeds a preset error reference value.   When the state in which the error between the calculated average value in the test mode and the current command value during rotation at the maximum rotation speed exceeds the preset error reference value continues for the preset time, the cooling water The cooling water state determination method according to claim 10, wherein it is determined that is in an abnormal circulation state.   The cooling water state determination method according to claim 9, wherein the error reference value is changed according to a rotation speed of the motor.   The cooling water state determination method according to claim 10, wherein when the test mode is enabled, the motor is maintained at a maximum rotation speed.   The cooling water state determination method according to claim 6, wherein the current command value corresponding to the rotation speed is obtained from a current command map already set according to the rotation speed. The step of determining normal circulation of the cooling water includes:
Calculating a deviation or variance of the current command value during the preset time and determining normal circulation of the cooling water based on a comparison result between the calculated deviation or variance and the preset reference value; The cooling water state determination method according to claim 6, further comprising:   16. The cooling water according to claim 15, wherein when the calculated deviation or dispersion value exceeds a preset reference value and continues for a preset time, the cooling water is determined to be in an abnormal circulation state. State judgment method.   16. The cooling water state determination method according to claim 15, further comprising a step of enabling a test mode when the calculated deviation or variance value exceeds a preset reference value.   The cooling water state determination method according to claim 17, wherein when the test mode is enabled, the motor is maintained at a maximum rotation speed. The step of determining normal circulation of the cooling water includes:
Integrating the error between the current command value corresponding to the rotation speed and the current command value to the motor, and determining the normal circulation of the cooling water based on a comparison result between the integrated value and a preset reference value; The cooling water state determination method according to claim 6, further comprising:   The cooling water state determination method according to claim 19, further comprising a step of normalizing the calculated average value by dividing the average value by a current command value in a normal state corresponding to the rotation speed.   The cooling water state determination method according to claim 19, wherein the cooling water is determined to be in an abnormal circulation state when the integral value exceeds a preset reference value and continues for a preset time.   The method of claim 19, further comprising enabling a test mode when the integrated value exceeds a preset reference value.   The cooling water state determination method according to claim 22, wherein when the test mode is enabled, the motor is maintained at a maximum rotation speed. Maintaining a constant rotation speed of a pump driving motor for circulating cooling water; and
After the rotation speed is maintained constant, if an error occurs between the output or torque value of the motor and the reference output or torque value in a normal state corresponding to the maintained rotation speed, the test mode is enabled. A cooling water state determination method comprising: a step.   25. The cooling water state determination method according to claim 24, wherein normal circulation of the cooling water is determined in the test mode while the motor is maintained at a maximum rotation speed.

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