CN111245204A - Motor controller and method and system for adaptively changing IBGT gate-level resistance value of motor controller - Google Patents

Abstract

The invention discloses a motor controller and a method and system for adaptively changing its IBGT gate-level resistance value. The method includes the following steps: (1) Detecting the best gate-level corresponding to the motor controller under different working conditions resistance value, obtain the corresponding relationship of “working condition-optimal gate-level resistance value”; (2) in the running state, measure the current motor controller working condition, according to the corresponding relationship of “working condition-optimal gate-level resistance value” Determine the optimal gate-level resistance value corresponding to the current working condition; (3) adjust the gate-level resistance value in the IGBT drive circuit to the optimal gate-level resistance value described in step (2). The invention can minimize the loss of the IGBT and improve the working efficiency of the IGBT under the premise of ensuring the safe operation of the IGBT.

Description

Motor controller and method and system for adaptively changing its IBGT gate resistance value

technical field

The invention relates to an IGBT driving method, in particular to a motor controller and a method and system for adaptively changing the value of its IGBT gate-level driving circuit.

Background technique

The power electronic system is mainly composed of the main circuit and the control circuit. Among them, the main circuit is composed of switching devices such as IGBTs. The operating environment of high-power IGBTs is generally harsh, and the voltage it can withstand can be as high as 1000 volts. If it is dealt with in time, it will cause very serious consequences. Especially in the field of new energy vehicles, IGBT is one of the core devices of the motor control unit in electric vehicles, and the design of the resistance value of its gate-level gate-level resistance is a key factor determining its performance.

The input voltage of the motor controller bus is both the output voltage of the high-voltage battery. Since the output voltage of the high-voltage battery has a wide range (200V-450V) or a higher voltage range, and the gate-level resistance of the current IGBT is mostly fixed resistance, in order to ensure that the IGBT gate is in the The turn-off voltage stress of the IGBT at the highest voltage and low temperature has a reasonable derating, and the gate-level resistance parameter needs to be increased. However, a larger gate-level resistance will increase the turn-off time of the IGBT, increase the loss, and at the same time increase the junction temperature, resulting in the IGBT Both the operating efficiency and the power density of the electronic control are affected. Taking Figure 1 as an example, the existing controller BUS input voltage range is relatively wide, and the rated voltage time of the electronic control operation is long. In order to ensure a reasonable derating of the IGBT turn-off voltage stress at the highest voltage, it is necessary to increase the gate resistance. R1 and R2 are design parameters, but obviously, larger R1 and R2 lead to longer turn-off time, larger IGBT loss, lower efficiency, and higher junction temperature, sacrificing the power density of electronic control; on the contrary, if R1 and R2 If the parameter design is too small, in extreme cases, the IGBT may exceed the SOA safe operating area.

In view of the above problems, the Chinese Patent Publication No. CN209375598U provides an IGBT varistor turn-on circuit, which realizes the varistor turn-on by dividing the voltage of the resistor, which reduces the risk during the operation of the IGBT to a certain extent, but it can only To achieve the switching of two different resistance values, the resistance value cannot be adjusted adaptively, and the problems of low switching efficiency and large loss of IGBT cannot be fundamentally solved.

The Chinese patent with publication number CN107342759A provides a digital intelligent IGBT driving method and system. The solution can be used to control the IGBT module to be turned on or off at a fixed time between power-on and power-off, further reducing the power consumption. It reduces the operational risk of the IGBT, but it cannot adjust the resistance value of the gate resistor of the IGBT to an optimal value, that is, it cannot maximize the loss reduction and improve the power density of the electronic control.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the first object of the present invention is to provide a method for adaptively changing the IGBT gate resistance value of the motor controller, which can minimize the loss of the IGBT under the premise of ensuring the safe operation of the IGBT, Improve the working efficiency of IGBT.

The second object of the present invention is to provide a system for adaptively changing the IGBT gate resistance value of a motor controller, which can be used to run the above method.

The third object of the present invention is to provide a motor controller, which includes the above-mentioned system for adaptively changing IGBT gate resistance.

In order to achieve the above object, one aspect of the present invention provides a method for adaptively changing the IGBT gate-level resistance value of a motor controller, the method comprising the following steps:

(1) Detect the optimal gate-level resistance value corresponding to the motor controller under different working conditions, and obtain the corresponding relationship of "working condition-optimal gate-level resistance value";

(2) In the running state, measure the current working condition of the motor controller, and determine the optimum gate-level resistance value corresponding to the current working condition according to the corresponding relationship of the “working condition-optimal gate-level resistance value”;

(3) Adjust the gate-level resistance value in the IGBT drive circuit to the optimum gate-level resistance value described in step (2).

Preferably, in step (1), detecting the optimal gate-level resistance value corresponding to different working conditions of the motor controller includes the following steps:

1) Set the initial working condition, and preset the initial value of gate resistance under the initial working condition;

2) Determine whether the IGBT exceeds the safe working area under the current gate resistance value;

If so, increase the gate-level resistance value, and then re-judg whether the IGBT exceeds the safe working area;

If not, judge whether it meets the derating standard. If so, take the current gate-level resistance value as the best gate-level resistance value under the current working condition. If not, reduce the gate-level resistance value until it decreases. As small as the minimum value that meets the IGBT derating standard, the minimum value is used as the optimal gate-level resistance value;

Adjust the working conditions and repeat steps 1)-2) until the detection of the optimal gate-level resistance value for all working conditions is completed.

Preferably, the derating standard of the IGBT is not higher than 80% of the full capacity.

Preferably, the corresponding relationship of "working condition-optimal gate-level resistance value" is a relation table of "working condition-optimal gate-level resistance value" or a relation curve of "working condition-optimal gate-level resistance value".

Preferably, in step (1), the operating conditions include the voltage value of the motor controller bus and the ambient temperature value.

Preferably, the method for adjusting the gate-level resistance value of the IGBT to the optimum gate-level resistance value described in step (2) is: according to the optimum gate-level resistance value, adjusting the gate level in the IGBT gate-level drive circuit connected in parallel number of resistors.

Another aspect of the present invention provides a system for adaptively changing the IGBT gate-level resistance value of a motor controller, the system includes a control unit, a detection unit, a high-low voltage isolation unit, an optimal gate-level resistance value adjustment unit, and a control unit with the motor The IGBT connected to the controller, the first connection end of the control unit is connected to the detection unit, and the second connection end of the control unit is connected to the optimum gate resistance value adjustment unit through the high and low voltage isolation unit , the IGBT is connected to the optimal gate-level resistance value adjustment unit, wherein,

The detection unit is used to determine the current working condition of the motor controller;

The control unit determines the optimal gate-level resistance value corresponding to the current working condition according to the corresponding relationship of the "working condition-optimal gate-level resistance value", and sends an adjusted gate-level resistance value to the optimal gate-level resistance value adjustment unit. control signal;

The optimum gate-level resistance value adjusting unit adjusts the gate-level resistance value of the IGBT to the optimum gate-level resistance value described in step (2) according to the control signal of the control unit.

Preferably, the optimal gate-level resistance value adjustment unit includes a plurality of reference resistors connected in parallel with each other, and each reference resistor is connected in series with an electrical switch, which is controlled to be turned on or off according to a control signal of the control unit The switch is used to adjust the reference resistance connected to the circuit, so as to adjust the gate resistance value of the IGBT to the optimum gate resistance value.

Preferably, the electrical switch includes a MOS transistor.

In yet another aspect of the present invention, a motor controller is provided, including the above-mentioned system for adaptively changing the IGBT gate resistance value of the motor controller.

Compared with the prior art, the beneficial effects of the present invention are:

The invention adaptively adjusts the IGBT gate-level resistance value to the optimum gate-level resistance value corresponding to the current working condition. The optimum gate-level resistance value not only prevents the gate-level circuit from being too small, but also ensures the safe operation of the IGBT. It also avoids the gate-level resistance from being too large. By selecting the best gate-level resistance, the loss of the IGBT can be minimized, the working efficiency of the IGBT can be improved, and the electrical control power density of the IGBT can be improved at the same time.

Description of drawings

The accompanying drawings that constitute a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute a limitation to the present application.

1 is a drive circuit diagram of an IGBT in the prior art;

2 is a flowchart of a method for determining an optimal gate-level resistance value of an IGBT under current operating conditions in an embodiment of the present invention;

FIG. 3 is a driving circuit diagram of an IGBT when applied to motor driving in an embodiment of the present invention.

Detailed ways

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

Furthermore, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front" , "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise", etc. indicate the orientation or position relationship as Based on the orientation or positional relationship shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood to limit the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise expressly defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

Below in conjunction with accompanying drawing and embodiment, the present invention will be further described:

This embodiment provides a method for adaptively changing an IGBT gate-level resistance value of a motor controller, and the method includes the following steps:

(1) Detect the optimal gate-level resistance value corresponding to the motor controller under different working conditions, and obtain the corresponding relationship of "working condition-optimal gate-level resistance value";

(2) In the running state, measure the current working condition of the motor controller, and determine the optimum gate-level resistance value corresponding to the current working condition according to the corresponding relationship of the “working condition-optimal gate-level resistance value”;

(3) Adjust the gate-level resistance value in the IGBT drive circuit to the optimum gate-level resistance value described in step (2).

As a preferred embodiment, as shown in Figure 2, in step (1), detecting the optimal gate-level resistance value corresponding to different working conditions of the motor controller includes the following steps:

1) Set the initial working condition, and preset the initial value of gate resistance under the initial working condition;

2) Determine whether the IGBT exceeds the safe working area under the current gate resistance value;

If so, increase the gate-level resistance value, and then re-judg whether the IGBT exceeds the safe working area;

If not, judge whether it meets the derating standard. If so, take the current gate-level resistance value as the best gate-level resistance value under the current working condition. If not, reduce the gate-level resistance value until it decreases. As small as the minimum value that meets the IGBT derating standard, the minimum value is used as the optimal gate-level resistance value;

Adjust the working conditions and repeat steps 1)-2) until the detection of the optimal gate-level resistance value for all working conditions is completed.

As a preferred embodiment, the derating standard of the IGBT is not higher than 80% of the full capacity.

As a preferred embodiment, the corresponding relationship of "working condition-optimal gate-level resistance value" is a relation table of "working condition-optimal gate-level resistance value" or "working condition-optimal gate-level resistance value" Relationship lines.

As a preferred embodiment, in step (1), the working conditions include the voltage value of the motor controller bus and the ambient temperature value.

As a preferred embodiment, the method for adjusting the gate resistance value of the IGBT to the optimal gate resistance value described in step (2) is: according to the optimal gate resistance value, adjust the gate resistance value connected in parallel with the IGBT gate. The number of gate resistors in the stage driver circuit.

This embodiment also provides a system for adaptively changing the IGBT gate-level resistance value of the motor controller, the system includes a control unit, a detection unit, a high-low voltage isolation unit, an optimal gate-level resistance value adjustment unit, and a connection with the motor controller IGBT, the first connection end of the control unit is connected to the detection unit, the second connection end of the control unit is connected to the optimum gate resistance value adjustment unit through the high and low voltage isolation unit, and the The IGBT is connected to the optimal gate-level resistance value adjustment unit, wherein,

The detection unit is used to determine the current working condition of the motor controller;

The control unit determines the optimal gate-level resistance value corresponding to the current working condition according to the corresponding relationship of the "working condition-optimal gate-level resistance value", and sends an adjusted gate-level resistance value to the optimal gate-level resistance value adjustment unit. control signal;

The optimum gate-level resistance value adjusting unit adjusts the gate-level resistance value of the IGBT to the optimum gate-level resistance value described in step (2) according to the control signal of the control unit.

As a preferred embodiment, the optimal gate-level resistance value adjustment unit includes a plurality of reference resistors connected in parallel with each other, and each reference resistor is connected in series with an electrical switch, which is controlled to be turned on according to the control signal of the control unit Or turn off the electrical switch to adjust the reference resistance connected to the circuit, so as to adjust the gate resistance value of the IGBT to the optimum gate resistance value.

As a preferred embodiment, the electrical switch includes a MOS transistor.

When the above system is applied to the motor driving process, the corresponding driving circuit includes: a low-voltage side circuit and a high-voltage side circuit, wherein the low-voltage side circuit and the high-voltage side circuit are isolated by an isolator, specifically, as shown in Figure 3:

The low-voltage side includes: a detection circuit and a control unit U1 (represented by functions as "TAB query module" and "control signal module" in Figure 3), wherein the detection circuit is used to detect the current working conditions of the motor controller (bus voltage, environment Among them, the bus voltage detection is to detect the voltage value between BUS+ and BUS- using the principle of resistance division; the ambient temperature is to be sensed or detected by the NTC thermistor); the TAB query module determines the The corresponding optimal gate-level resistance value; a mathematical operation table is stored in the control signal module, which is used to generate a combination of execution circuits according to the required optimal resistance, that is, the required optimal gate-level resistance value is expressed by a set of reference values. , such as: the reference value is: a=1, b=5, c=10, d=20, f=30. If the currently determined optimal gate resistance value is 36, then 36=1*a+1*b+c*0+d*0+1*f.

The signal control module determines the opening and closing of each electrical switch in the optimal gate resistance value adjustment unit according to the optimal gate resistance value corresponding to the working condition of the motor controller. It can be seen from Figure 3 that the control unit U1 is connected to the drive of the IGBT respectively. Chip U2 and high and low voltage isolation chips U3 and U4, and in the optimal gate-level resistance adjustment unit: B ₁ -B _n , T ₁ -T _n are electrical switches, Rb1-Rbn, Rt1-Rtn and R1, R2 are benchmarks It can be seen from Figure 3 that the reference resistors (Rb1-Rbn, Rt1-Rtn) connected to the high and low voltage isolation chips are connected in parallel with each other, and at the same time, each reference resistor is connected in series with an electrical switch, so that the optimal gate The stage resistance adjustment unit can control to open or close the electrical switch according to the control signal of the control unit to adjust the reference resistance connected to the circuit, that is, through the opening and closing combination of different electrical switches, the gate resistance value can be adaptively changed , so as to adjust the gate-level resistance value of the IGBT to the optimum gate-level resistance value.

In addition, the above-mentioned TAB query module stores the corresponding relationship of "working condition-optimal gate-level resistance value", and the corresponding relationship may be in the form of a table or a fitted curve.

This embodiment also provides a motor controller, including the above-mentioned system for adaptively changing the IGBT gate resistance value of the motor controller.

The invention adaptively adjusts the IGBT gate-level resistance value to the optimum gate-level resistance value corresponding to the current working condition. The optimum gate-level resistance value not only prevents the gate-level circuit from being too small, but also ensures the safe operation of the IGBT. ; It also avoids the gate-level resistance from being too large, maximally reduces the loss of the IGBT, improves the working efficiency of the IGBT, and at the same time improves the electrical control power density of the IGBT.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and those of ordinary skill in the art will not depart from the principles and spirit of the present invention Under the circumstance of the present invention, the above-described embodiments can be changed, modified, replaced and modified within the scope of the present invention, and any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to the present invention within the scope of the technical solution.

Claims (10)

1. a method for adaptively changing the IGBT gate-level resistance value of a motor controller, is characterized in that, comprises the steps: (1) Detect the optimal gate-level resistance value corresponding to the motor controller under different working conditions, and obtain the corresponding relationship of "working condition-optimal gate-level resistance value"; (2) In the running state, measure the current working condition of the motor controller, and determine the optimum gate-level resistance value corresponding to the current working condition according to the corresponding relationship of the “working condition-optimal gate-level resistance value”; (3) Adjust the gate-level resistance value in the IGBT drive circuit to the optimum gate-level resistance value described in step (2). 2. The method for adaptively changing the IGBT gate-level resistance value of the motor controller according to claim 1, wherein in step (1), the optimal gate corresponding to different operating conditions of the motor controller is detected Stage resistance value includes the following steps: 1) Set the initial working condition, and preset the initial value of gate resistance under the initial working condition; 2) Determine whether the IGBT exceeds the safe working area under the current gate resistance value; If so, increase the gate-level resistance value, and then re-judg whether the IGBT exceeds the safe working area; If not, judge whether it meets the derating standard. If so, take the current gate-level resistance value as the best gate-level resistance value under the current working condition. If not, reduce the gate-level resistance value until it decreases. As small as the minimum value that meets the IGBT derating standard, the minimum value is used as the optimal gate-level resistance value; Adjust the working conditions and repeat steps 1)-2) until the detection of the optimal gate-level resistance value for all working conditions is completed. 3 . The method for adaptively changing the gate resistance value of the IGBT of the motor controller according to claim 2 , wherein the derating standard of the IGBT is not higher than 80% of the full rating. 4 . 4 . The method for adaptively changing the IGBT gate-level resistance value of the motor controller according to claim 1 , wherein the “working condition-optimal gate-level resistance value” corresponding relationship is “working condition- "Optimum gate resistance value" relationship table or "working condition - optimal gate resistance value" relationship curve. 5 . The method for adaptively changing the IGBT gate resistance value of the motor controller according to claim 1 , wherein in step (1), the operating conditions include the voltage value of the motor controller bus and the environment. 6 . temperature value. 6 . The method for adaptively changing the IGBT gate-level resistance value of the motor controller according to claim 1 , wherein the gate-level resistance value of the IGBT is adjusted to the optimal gate level described in step (2). 7 . The method for the resistance value is as follows: according to the optimal gate-level resistance value, adjusting the number of gate-level resistors connected in parallel in the IGBT gate-level drive circuit. 7. A system for adaptively changing the IGBT gate-level resistance value of the motor controller, characterized in that it comprises a control unit, a detection unit, a high-low voltage isolation unit, an optimum gate-level resistance value adjustment unit and a IGBT, the first connection end of the control unit is connected to the detection unit, the second connection end of the control unit is connected to the optimum gate resistance value adjustment unit through the high and low voltage isolation unit, and the IGBT connected with the optimal gate-level resistance value adjustment unit, wherein, The detection unit is used to determine the current working condition of the motor controller; The control unit determines the optimal gate-level resistance value corresponding to the current operating condition according to the corresponding relationship of the "working condition-optimal gate-level resistance value", and sends an adjusted gate-level resistance value to the optimal gate-level resistance value adjustment unit. control signal; The optimum gate-level resistance value adjusting unit adjusts the gate-level resistance value of the IGBT to the optimum gate-level resistance value described in step (2) according to the control signal of the control unit. 8. The system for adaptively changing the IGBT gate-level resistance value of the motor controller according to claim 7, wherein the optimal gate-level resistance value adjustment unit comprises a plurality of reference resistors connected in parallel with each other, An electrical switch is connected in series with each reference resistor, and the electrical switch is controlled to be turned on or off according to the control signal of the control unit to adjust the reference resistor connected to the circuit, so as to adjust the gate resistance value of the IGBT to the optimal gate stage resistance value. 9 . The system for adaptively changing the IGBT gate resistance value of the motor controller according to claim 8 , wherein the electrical switch comprises a MOS transistor. 10 . 10. A motor controller, characterized by comprising the system for adaptively changing the IGBT gate-level resistance value of the motor controller according to any one of claims 7-9.

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