Motor controller and IGBT overheating protection device and method

Abstract

A motor controller and an IGBT overheat protection device and method, the motor controller comprises the IGBT overheat protection device, the IGBT overheat protection device and method are used for protecting an IGBT module of the motor controller from being overheated to affect the service life or be damaged, and the IGBT overheat protection method comprises the following steps: obtaining the output torque and the rotating speed of a motor, and recording the working time of the motor controller; when the working time of the motor controller meets a preset time range, collecting an IGBT real-time temperature value of the motor controller; calculating a temperature change slope K of adjacent time intervals of an IGBT (Insulated Gate Bipolar Translator) of the motor controller within a preset time range; comparing the temperature change slope K with a standard temperature change slope threshold value K, and comparing the IGBT real-time temperature value Tn with an IGBT protection absolute temperature T0 at the same time; and selecting the motor controller to be in a normal working state or be switched to be in a working stop state according to a comparison result.

Description

Technical Field

[0001] The invention relates to electric vehicle motor control technology, in particular to a motor controller and an IGBT overheat protection device and method. Background Art

[0002] The motor controller of the motor vehicle drive system drives and controls the operation of the motor. The IGBT (Insulated Gate Bipolar Transistor) module is a key component of the motor controller. The commonly used cooling method is water cooling. The IGBT module in the motor controller is the main heat source, and the normal operation and heat dissipation requirements of the cooling system are relatively high. At present, the IGBT overheat protection of the motor controller usually adopts the absolute temperature protection point method. The absolute temperature protection point is set by absolute temperature protection. Once the absolute temperature point is reached, the output will be reduced or the work will stop.

[0003] When the motor system is running, if the water pump of the cooling system is not started, or the cooling system circuit fails and becomes blocked, there is water in the cooling system pipe but the water does not flow, or the water flows very slowly. At this time, the whole vehicle is operated normally and instructions are sent to the motor controller. Since the IGBT of the motor controller dissipates heat slowly, the temperature of the IGBT changes rapidly. Using absolute temperature protection point for protection will cause delayed protection, causing the IGBT of the motor controller to overheat, affecting the life of the device or even causing breakdown damage. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a motor controller and an IGBT overheat protection device and method in view of the above-mentioned defects of the prior art.

[0005] In order to achieve the above object, the present invention provides an IGBT overheat protection method for a motor controller, wherein the method is used to protect the IGBT module of the motor controller from overheating and affecting its life or damage, and comprises the following steps:

[0006] S100, obtaining the output torque and motor speed of the motor, and recording the working time of the motor controller;

[0007] S200, when the working time of the motor controller meets the preset time range, collecting the real-time temperature value of the IGBT of the motor controller;

[0008] S300, calculating the temperature change slope K of the IGBT of the motor controller in adjacent time intervals within a preset time range;

[0009] S400, comparing the temperature change slope K with the standard temperature change slope threshold ΔK, and at the same time comparing the IGBT real-time temperature value T nIGBT protection absolute temperature △T 0 ;as well as

[0010] S500, selecting the motor controller to be in a normal working state or switched to a stopped working state according to the comparison result.

[0011] The above-mentioned IGBT overheat protection method of the motor controller, wherein step S100 further includes determining the output torque T of the motor rq With the maximum torque T max , and the relationship between motor speed n and stall speed N.

[0012] The above-mentioned IGBT overheat protection method of the motor controller, wherein the preset time range is 0~t 0 , t 0 is the preset time point, t 0 =15-25s.

[0013] In the above-mentioned IGBT overheat protection method of the motor controller, the standard temperature change slope threshold △K includes △K 0 and △K 1 , △K 0 is the standard temperature change slope threshold of the motor controller when the motor is at maximum torque and n≤N; △K 1 is the standard temperature change slope threshold of the motor controller when the motor torque is at maximum and n>N.

[0014] The above-mentioned IGBT overheat protection method of the motor controller, wherein △K 0 =3.5, △K 1 =2.0.

[0015] In the above-mentioned IGBT overheat protection method of the motor controller, when T rq =T max , and n≤N, if K≥△K 0 , the motor controller stops working; when K<△K 0 , and T n ≥△T 0 When K<△K 0 , and T n <△T 0 , the motor controller works normally according to the actual working conditions.

[0016] In the above-mentioned IGBT overheat protection method of the motor controller, when T rq =T rmax , and n>N, if K≥△K 1 , then the motor controller stops working; if K<△K 1 , and Tn ≥△T 0 When K<△K 1 , and T n <△T 0 , the motor controller operates normally according to the actual working conditions.

[0017] In the above-mentioned IGBT overheat protection method of the motor controller, the locked-rotor speed N is 50 rpm.

[0018] In order to better achieve the above-mentioned purpose, the present invention further provides an IGBT overheat protection device for a motor controller, which is installed in a housing of the motor controller and is used to implement the above-mentioned IGBT overheat protection method for the motor controller. The IGBT overheat protection device includes an IGBT drive module and a control module connected to each other, and the IGBT drive module is connected to the IGBT module of the motor controller. The IGBT overheat protection device includes:

[0019] The acquisition unit is used to obtain the output torque and motor speed of the motor and determine the output torque T of the motor. rq With the maximum torque T max , and the relationship between the motor speed n and the stall speed N;

[0020] A timing unit, used for recording the working time of the motor controller;

[0021] A collection unit, used for collecting the real-time temperature value of the IGBT of the motor controller when the working time meets the preset time range;

[0022] A calculation unit, used to calculate a temperature change slope K of adjacent time intervals of the IGBT within the preset time range;

[0023] A comparison unit is used to compare the temperature change slope K with the standard temperature change slope threshold ΔK, and to compare the IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 ;as well as

[0024] The control unit is used to select the motor controller to be in a normal working state or to switch to a stopped working state according to the comparison result of the comparison unit.

[0025] In order to better achieve the above-mentioned purpose, the present invention also provides a motor controller, which includes the above-mentioned IGBT overheat protection device.

[0026] The technical effects of the present invention are:

[0027] The present invention compares the temperature change slope value K of the IGBT module of the motor controller in real time adjacent time intervals with the corresponding standard temperature change slope threshold △K under different working conditions within a preset time range. 0 , △K 1 Compare and judge, and according to the detected IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 The comparison is combined to effectively control the motor controller, thereby solving the problem that when a cooling system circuit fails, the IGBT module of the motor controller is affected by overheating and even suffers breakdown damage.

[0028] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a motor controller according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic structural diagram of an IGBT overheat protection device according to an embodiment of the present invention;

[0031] Figure 3 A working principle diagram of a motor controller according to an embodiment of the present invention;

[0032] Figure 4 This is a flow chart of an IGBT overheat protection method according to an embodiment of the present invention;

[0033] Figure 5 This is a working principle diagram of IGBT overheat protection according to an embodiment of the present invention.

[0034] Among them, the reference numerals

[0035] 1. Drive motor

[0036] 2 Motor Controller

[0037] 21 Cabinet

[0038] 22IGBT overheat protection device

[0039] 221 driver board

[0040] 222IGBT driver module

[0041] 223 control module

[0042] 23IGBT module

[0043] 24 Film capacitors

[0044] S100-S500 steps DETAILED DESCRIPTION

[0045] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0046] See also Figure 1-Figure 3 , Figure 1 This is a schematic diagram of the structure of a motor controller 2 according to an embodiment of the present invention. Figure 2 FIG. 2 is a schematic structural diagram of an IGBT overheat protection device 22 according to an embodiment of the present invention. Figure 3 The working principle diagram of the motor controller 2 of one embodiment of the present invention. The motor controller 2 of the present invention is electrically connected to the power supply and the drive motor 1, and is connected to the drive motor 1 through a data line to perform rotation and temperature detection on the drive motor 1. The motor controller 2 is used to drive the motor 1, and can obtain the motor output torque and motor speed in real time, and control the motor output torque and motor speed. The motor controller 2 includes a housing 21 and an IGBT module 23, a thin film capacitor 24 and an IGBT overheating protection device 22 installed in the housing 21. Since the composition, structure, relative position relationship, connection relationship and function of other parts of the motor controller 2 are all relatively mature existing technologies, they will not be repeated here. Only the IGBT overheating protection device 22 of the present invention is described in detail below.

[0047] The IGBT overheat protection device 22 of the motor controller 2 of the present invention is installed in the housing 21 of the motor controller 2, and is used to implement the IGBT overheat protection of the motor controller 2. The IGBT overheat protection device 22 includes an IGBT drive module 222 and a control module 223 connected to each other. The IGBT drive module 222 and the control module 223 are connected by a wiring harness. The IGBT drive module 222 is installed on a drive board 221 and is connected to the IGBT module 23 of the motor controller 2. The IGBT module 23 is connected to a thin film capacitor 24. The IGBT overheat protection device 22 includes: an acquisition unit, which is used to acquire the output torque and motor speed of the motor, and judge the output torque T of the motor. rq With the maximum torque T max , and the relationship between the motor speed n and the stall speed N; a timing unit for recording the working time of the motor controller 2; a collection unit for collecting the real-time temperature value of the IGBT of the motor controller 2 when the working time meets the preset time range; a calculation unit for calculating the temperature change slope K of the adjacent time intervals of the IGBT within the preset time range; a comparison unit for comparing the temperature change slope K with the standard temperature change slope threshold △K, and at the same time comparing the real-time temperature value T of the IGBT n IGBT protection absolute temperature △T 0and a control unit for selecting the motor controller 2 to be in a normal working state or to be switched to a stop working state according to the comparison result of the comparison unit.

[0048] See also Figure 4 and Figure 5 , Figure 4 This is a flow chart of an IGBT overheat protection method according to an embodiment of the present invention. Figure 5 The IGBT overheat protection working principle diagram of an embodiment of the present invention. The IGBT overheat protection method of the motor controller 2 of the present invention is used to protect the IGBT module 23 of the motor controller 2 from overheating and affecting the life or damage, and includes the following steps:

[0049] Step S100, obtaining the output torque and motor speed of the motor, and recording the working time of the motor controller 2;

[0050] Step S200: When the working time of the motor controller 2 meets the preset time range, the real-time temperature value of the IGBT of the motor controller 2 is collected; wherein the preset time range is 0~t 0 , t 0 is the preset time point, t 0 =15-25s, preferably t 0 =20s;

[0051] Step S300, calculating the temperature change slope K of the IGBT of the motor controller 2 in adjacent time intervals within a preset time range;

[0052] Step S400, compare the temperature change slope K with the standard temperature change slope threshold ΔK, and simultaneously compare the IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 ; Wherein, the standard temperature change slope threshold △K includes △K 0 and △K 1 , △K 0 is the standard temperature change slope threshold of the motor controller 2 when the motor torque is at maximum and n≤N; △K 1 is the standard temperature change slope threshold of the motor controller 2 when the motor is at maximum torque and n>N; preferably △K 0 =3.5, △K 1 = 2.0; and

[0053] Step S500: Select the motor controller 2 to be in a normal working state or switched to a stopped working state according to the comparison result. rq =T max , and n≤N, if K≥△K 0 , the motor controller 2 stops working; when K<△K0 , and T n ≥△T 0 When K<△K 0 , and T n <△T 0 , the motor controller 2 works normally according to the actual working conditions. rq =T rmax , and n>N, if K≥△K 1 , then the motor controller 2 stops working; if K<△K 1 , and T n ≥△T 0 When K<△K 1 , and T n <△T 0 , the motor controller 2 operates normally according to the actual working conditions.

[0054] In step S100 of this embodiment, it also includes determining the output torque T of the motor. rq With the maximum torque T max , and the relationship between the motor speed n and the stall speed N, the stall speed N is preferably 50rpm.

[0055] In this embodiment, when the motor controller 2 outputs the motor torque T rq =T rmax , when the speed n≤50rpm:

[0056] At the preset time 0~t 0 Within the range, the temperature value of the IGBT is obtained in real time. 1 ,t 2 ,t 3 ……t n The IGBT temperature values ​​are T 1 , T 2 , T 3 ……T n At this time, the temperature change slope of the motor controller 2 IGBT is The calculation unit calculates the temperature change slope value K of adjacent time intervals in real time and compares it with the corresponding standard temperature change slope threshold △K 0 For comparison, if the temperature change slope K ≥ △K 0 , then the motor controller 2 stops working;

[0057] At time 0~t 0 Within the range, when the temperature change slope K<△K 0 , and the actual IGBT real-time temperature value T n ≥△T 0 When , the motor controller 2 stops working;

[0058] At time 0~t 0 Within the range, when the temperature change slope K<△K 0 , and the actual IGBT real-time temperature value T n <△T 0 , no alarm is given, and the motor controller 2 operates normally according to the actual working conditions.

[0059] When the motor controller 2 outputs torque T rq =T rmax , when the speed n>50rpm:

[0060] At the preset time 0~t 0 Within the range, the temperature value of the IGBT is obtained in real time. 1 ,t 2 ,t 3 ……t n The IGBT temperature values ​​are T 1 , T 2 , T 3 ……T n At this time, the temperature change slope of the motor controller 2 IGBT is The calculation unit calculates the temperature change slope value K of adjacent time intervals in real time and compares it with the corresponding standard temperature change slope threshold △K 1 For comparison, if the temperature change slope K ≥ △K 1 , then the motor controller 2 stops working;

[0061] At time 0~t 0 Within the range, if the temperature change slope K<△K 1 , when the actual IGBT real-time temperature value T n ≥△T 0 When , the motor controller 2 stops working;

[0062] At time 0~t 0 Within the range, if the temperature change slope K<△K 1 , and the actual IGBT real-time temperature value T n <△T 0 , the motor controller 2 works normally according to the actual working conditions.

[0063] Among them, T rq is the output torque of the motor controller 2; T max is the maximum output torque of the motor; t 0 is the preset time point, which can be t 0 =20s; t n is the nth time point within the preset time, where n=40; ​​T n Forn At the moment, the real-time temperature value of the IGBT; K is the temperature change slope value of the adjacent time interval, K = K 1 , K 2 , K 3 ...K n-1 ; △K 0 is the standard temperature change slope threshold of motor controller 2 when the maximum torque and speed are <50rpm, which can be taken as △K 0 =3.5; △K 1 is the standard temperature change slope threshold of motor controller 2 when the maximum torque and speed are >50rpm, which can be taken as △K 1 =2.0; △T 0 is the absolute temperature of the IGBT protection of the motor controller 2, which can be taken as △T 0 =90°C. The speed of 50rpm is used as a node to determine whether the drive motor 1 is in a stalled state. A speed less than 50rpm indicates a stalled state, and a speed greater than 50rpm indicates a non-stalled state. The standard temperature change slope threshold △K 0 Compared with the standard temperature change slope threshold △K 1 These are the optimal parameter values ​​obtained based on practical applications and a large amount of experimental data.

[0064] The present invention compares the temperature change slope value K of the IGBT module 23 of the motor controller 2 in real time adjacent time intervals with the corresponding standard temperature change slope threshold △K under different working conditions within a preset time range. 0 , △K 1 Compare and judge, and according to the detected IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 By comparing and combining, the motor controller 2 is effectively controlled, thereby solving the problem that when a cooling system circuit fails, the IGBT module 23 of the motor controller 2 is affected by overheating and even suffers breakdown damage.

[0065] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. An IGBT overheat protection method for a motor controller, It is characterized in that The IGBT module used to protect the motor controller from overheating and thus affecting its life or damage includes the following steps: S100, obtaining the output torque and motor speed of the motor, and recording the working time of the motor controller; S200, when the working time of the motor controller meets the preset time range, collecting the real-time temperature value of the IGBT of the motor controller; S300, calculating the temperature change slope K of the IGBT of the motor controller in adjacent time intervals within a preset time range; S400, comparing the temperature change slope K with the standard temperature change slope threshold ΔK, and at the same time comparing the IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 ; as well as S500, selecting the motor controller to be in a normal working state or switched to a stopped working state according to the comparison result.

2. The IGBT overheat protection method of the motor controller according to claim 1, It is characterized in that Step S100 also includes determining the output torque T of the motor rq With the maximum torque T max , and the relationship between motor speed n and stall speed N.

3. The IGBT overheat protection method of the motor controller as claimed in claim 2, It is characterized in that The preset time range is 0~t 0 , t 0 is the preset time point, t 0 =15-25s.

4. The IGBT overheat protection method of the motor controller as claimed in claim 2, It is characterized in that The standard temperature change slope threshold △K includes △K 0 and △K 1 , △K 0 is the standard temperature change slope threshold of the motor controller when the motor is at maximum torque and n≤N; △K 1 is the standard temperature change slope threshold of the motor controller when the motor torque is at maximum and n>N.

5. The IGBT overheat protection method of the motor controller as claimed in claim 4, It is characterized in that △K 0 =3.5,△K 1 =2.0。 6. The IGBT overheat protection method of the motor controller as claimed in claim 4, It is characterized in that When T rq =T max , and n≤N, if K≥△K 0 , the motor controller stops working; when K<△K 0 , and T n ≥△T 0 When K<△K 0 , and T n <△T 0 , the motor controller works normally according to the actual working conditions.

7. The IGBT overheat protection method of the motor controller as claimed in claim 4, It is characterized in that When T rq =T rmax , and n>N, if K≥△K 1 , then the motor controller stops working; if K<△K 1 , and T n ≥△T 0 When K<△K 1 , and T n <△T 0 , the motor controller operates normally according to the actual working conditions.

8. The IGBT overheat protection method of the motor controller according to any one of claims 2 to 7, It is characterized in that The stall speed N is 50 rpm.

9. An IGBT overheat protection device for a motor controller, It is characterized in that Installed in the housing of the motor controller, used to implement the IGBT overheat protection method of the motor controller according to any one of claims 1 to 8, the IGBT overheat protection device comprises an IGBT drive module and a control module connected to each other, the IGBT drive module is connected to the IGBT module of the motor controller, and the IGBT overheat protection device comprises: The acquisition unit is used to obtain the output torque and motor speed of the motor and determine the output torque T of the motor. rq With the maximum torque T max , and the relationship between the motor speed n and the stall speed N; A timing unit, used for recording the working time of the motor controller; A collection unit, used for collecting the real-time temperature value of the IGBT of the motor controller when the working time meets the preset time range; A calculation unit, used to calculate a temperature change slope K of adjacent time intervals of the IGBT within the preset time range; A comparison unit is used to compare the temperature change slope K with the standard temperature change slope threshold ΔK, and to compare the IGBT real-time temperature value T n IGBT protection absolute temperature △T 0 ;as well as The control unit is used to select the motor controller to be in a normal working state or to switch to a stopped working state according to the comparison result of the comparison unit.

10. A motor controller, It is characterized in that Includes the IGBT overheat protection device as described in claim 9.

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