Motor controller cooling liquid flow control method and system

Abstract

The invention discloses a motor controller cooling liquid flow control method and system, and the method comprises the steps: collecting the junction temperature of an IGBT power module in a motor controller in real time, and comparing the junction temperature with a preset temperature sampling range; when the junction temperature exceeds a preset temperature sampling range, obtaining a basic cooling liquid flow related to the current motor rotating speed, the current motor torque and the current bus voltage; calculating a cooling liquid flow request value according to the basic cooling liquid flow and a preset cooling control strategy; taking the cooling liquid flow request value as the cooling liquid flow of the motor controller in the next cooling operation cycle; and repeating the steps S1-S4 according to the cooling operation cycle to update the cooling liquid flow of the motor controller until the collected junction temperature of the IGBT power module accords with a preset temperature sampling range. According to the motor controller cooling liquid flow control method and system, the power consumption of the cooling liquid control loop can be dynamically adjusted by a vehicle thermal management system, and therefore the loss of a vehicle low-voltage power source is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of motor controllers, and in particular to a method and system for controlling coolant flow of a motor controller. Background Art

[0002] Motor controllers are widely used in pure electric vehicles and hybrid electric vehicles. The motor controller converts the DC power of the power battery into AC power to generate torque for the motor, thereby providing power for the entire vehicle. The IGBT power module is the core component of the motor controller, and the junction temperature of the IGBT power module must be kept below the specified threshold to ensure the normal operation of the motor controller. In order to make the motor controller work at a normal temperature, the whole vehicle usually provides coolant by a water pump, and the coolant takes away the heat generated by the power module through a reasonably designed water channel. Usually, the thermal management system of the whole vehicle adjusts the power of the water pump according to the junction temperature reported by the motor controller, and allocates the water flow of the corresponding temperature to achieve the purpose of cooling the motor controller and reducing the power consumption of the water pump. However, the thermal management system of the whole vehicle cannot accurately meet the cooling requirements of the motor controller, which may cause excessive power consumption of the water pump or overheating of the power module of the motor controller. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention proposes a motor controller coolant flow control method and system.

[0004] A motor controller coolant flow control method proposed by the present invention comprises the following steps:

[0005] S1, collecting the junction temperature of the IGBT power module in the motor controller in real time, and comparing the junction temperature with a preset temperature sampling range;

[0006] S2. When the junction temperature exceeds the preset temperature sampling range, the basic coolant flow rate related to the current motor speed, motor torque and bus voltage is obtained;

[0007] S3, calculating a coolant flow request value according to a basic coolant flow and a preset cooling control strategy;

[0008] S4, using the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle;

[0009] S5. Repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

[0010] Preferably, the basic coolant flow rate is obtained as follows:

[0011] The corresponding basic coolant flow rate is queried from a preset coolant flow rate query database according to the current motor speed, motor torque and bus voltage.

[0012] Preferably, the preset coolant flow query database is pre-configured with multiple coolant flow query tables, and the multiple coolant flow query tables correspond one to one to multiple bus voltage ranges; the coolant flow query table is pre-configured with a mapping relationship between motor speed, motor torque and basic coolant flow, wherein a set of motor speed and motor torque corresponds to a basic coolant flow.

[0013] Preferably, querying the corresponding basic coolant flow rate from a preset coolant flow rate query database according to the current motor speed, motor torque and bus voltage specifically includes:

[0014] Determine a first type of coolant flow query table from a preset coolant flow query database according to the current bus voltage;

[0015] According to the current motor speed and motor torque, the corresponding basic coolant flow rate is queried from the first type coolant flow rate query table.

[0016] Preferably, the preset cooling control strategy specifically includes:

[0017] Obtaining a preset cooling threshold value adjusted for each cooling operation cycle;

[0018] When the junction temperature is below the lower limit of the preset temperature sampling range, the basic coolant flow rate is reduced by a step size equal to the cooling threshold value each time a cooling operation cycle is run under the current working condition to obtain a coolant flow rate request value for the next cooling operation cycle;

[0019] When the junction temperature is above the upper limit of the preset temperature sampling range, the basic coolant flow rate is increased by a step size equal to the cooling threshold each time a cooling operation cycle is run under the current working condition to obtain the coolant flow rate request value for the next cooling operation cycle.

[0020] Preferably, it also includes:

[0021] S6. When the coolant flow rate of the motor controller reaches the preset maximum coolant flow rate limit or the minimum coolant flow rate limit, stop repeatedly calculating the coolant flow rate request value; use the maximum coolant flow rate limit or the minimum coolant flow rate limit as the coolant flow rate of the motor controller in the subsequent cooling operation cycle; until the collected junction temperature of the IGBT power module meets the preset temperature sampling range, execute the coolant flow rate value of the motor controller corresponding to the preset temperature sampling range.

[0022] Preferably, before step S1, the method further includes:

[0023] Build a coolant flow query database;

[0024] The bus voltage range is divided into a plurality of bus voltage range segments, and a coolant flow query table is constructed correspondingly to the plurality of bus voltage range segments;

[0025] A plurality of sets of motor speeds and motor torques and a plurality of basic coolant flow rates are configured in the coolant flow query table, wherein a set of motor speeds and motor torques corresponds to a basic coolant flow rate.

[0026] Preferably, it also includes:

[0027] S7. When the coolant flow request value reaches the preset maximum coolant flow limit and the junction temperature of the IGBT power module collected within a preset time period is still above the upper limit of the preset temperature sampling range, a preset power reduction protection operation is performed.

[0028] The present invention provides a motor controller coolant flow control system, comprising:

[0029] A data acquisition module is used to collect the junction temperature of the IGBT power module in the motor controller in real time and compare the junction temperature with a preset temperature sampling range;

[0030] A first processing module, for obtaining a basic coolant flow rate related to a current motor speed, motor torque, and bus voltage when the junction temperature exceeds a preset temperature sampling range;

[0031] A second processing module, configured to calculate a coolant flow request value according to a basic coolant flow and a preset cooling control strategy;

[0032] A third processing module, configured to use the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle;

[0033] The execution module is used to repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

[0034] In the present invention, the proposed motor controller coolant flow control method and system collects the junction temperature of the IGBT power module in the motor controller in real time, and compares the junction temperature with the preset temperature sampling range; when the junction temperature exceeds the preset temperature sampling range, obtains the basic coolant flow related to the current motor speed, motor torque and bus voltage; calculates the coolant flow request value according to the basic coolant flow and the preset cooling control strategy; uses the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range. By real-time monitoring of the junction temperature of the IGBT power module and dynamically adjusting the coolant flow according to the comparison result of the junction temperature and the preset temperature sampling range, the cooling efficiency can be effectively improved, the service life of the motor controller can be extended, and the stable operation of the motor controller under various working conditions can be ensured, so that the vehicle thermal management system can dynamically adjust the power consumption of the coolant control loop, thereby reducing the loss of the low-voltage power supply of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the working process structure of a motor controller coolant flow control method proposed by the present invention;

[0036] Figure 2 A schematic diagram of the implementation process of a motor controller coolant flow control method proposed by the present invention;

[0037] Figure 3 A schematic diagram of the system architecture of a motor controller coolant flow control system proposed by the present invention. DETAILED DESCRIPTION

[0038] Reference Figure 1-3 The present invention provides a motor controller coolant flow control method, comprising the following steps:

[0039] S0. Construct a coolant flow query database; divide the bus voltage range into multiple bus voltage range segments, and construct a coolant flow query table for the multiple bus voltage range segments one by one; configure multiple groups of motor speeds and motor torques and multiple basic coolant flow rates in the coolant flow query table, wherein one group of motor speeds and motor torques corresponds to one basic coolant flow rate.

[0040] S1. Collect the junction temperature of the IGBT power module in the motor controller in real time, and compare the junction temperature with the preset temperature sampling range.

[0041] S2. When the junction temperature exceeds the preset temperature sampling range, the basic coolant flow rate related to the current motor speed, motor torque and bus voltage is obtained.

[0042] In this embodiment, the process of acquiring the basic coolant flow rate is as follows: querying the corresponding basic coolant flow rate from a preset coolant flow rate query database according to the current motor speed, motor torque and bus voltage.

[0043] Specifically, a first type of coolant flow query table is determined from a preset coolant flow query database according to the current bus voltage; and a corresponding basic coolant flow is queried from the first type of coolant flow query table according to the current motor speed and motor torque.

[0044] In this embodiment, a preset coolant flow query database is pre-configured with multiple coolant flow query tables, and the multiple coolant flow query tables correspond one to one to multiple bus voltage ranges; the coolant flow query table is pre-configured with a mapping relationship between motor speed, motor torque and basic coolant flow, wherein a set of motor speed and motor torque corresponds to a basic coolant flow.

[0045] S3. Calculate a coolant flow request value according to a basic coolant flow and a preset cooling control strategy.

[0046] In this embodiment, the preset cooling control strategy specifically includes:

[0047] Obtaining a preset cooling threshold value adjusted for each cooling operation cycle;

[0048] When the junction temperature is below the lower limit of the preset temperature sampling range, the basic coolant flow rate is reduced by a step size equal to the cooling threshold value each time a cooling operation cycle is run under the current working condition to obtain a coolant flow rate request value for the next cooling operation cycle;

[0049] When the junction temperature is above the upper limit of the preset temperature sampling range, the basic coolant flow rate is increased by a step size equal to the cooling threshold each time a cooling operation cycle is run under the current working condition to obtain the coolant flow rate request value for the next cooling operation cycle.

[0050] In this embodiment, when the junction temperature of the IGBT power module exceeds the upper limit of the preset temperature sampling range, the coolant flow request value is increased until the temperature of the IGBT power module is stabilized within a safe preset temperature sampling range; when the junction temperature of the power module is lower than the lower limit of the threshold, the coolant flow value is appropriately reduced to reduce the power consumption of the vehicle thermal management system.

[0051] S4. Using the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle.

[0052] S5. Repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

[0053] S6. When the coolant flow rate of the motor controller reaches the preset maximum coolant flow rate limit or the minimum coolant flow rate limit, stop repeatedly calculating the coolant flow rate request value; use the maximum coolant flow rate limit or the minimum coolant flow rate limit as the coolant flow rate of the motor controller in the subsequent cooling operation cycle; until the collected junction temperature of the IGBT power module meets the preset temperature sampling range, execute the coolant flow rate value of the motor controller corresponding to the preset temperature sampling range.

[0054] In this embodiment, if the coolant flow request value output by the junction temperature compensation of the IGBT power module is greater than the preset maximum coolant flow limit value, the final coolant flow request value is the preset maximum coolant flow limit value.

[0055] In this embodiment, if Figure 2 As shown, for example, the preset temperature sampling range is [80℃, 140℃], the maximum cooling water flow limit is 8L / min, the minimum cooling water flow limit is 4L / min, and the maximum cooling water flow limit and the minimum cooling water flow limit are defined according to the vehicle thermal management system. The preset cooling threshold for each cooling operation cycle adjustment is 1L / min. Let the basic coolant flow queried be X. When the junction temperature is below the lower limit of the preset temperature sampling range, the coolant flow request value for the next cooling operation cycle is X-1; the coolant flow request value for the next cooling operation cycle is X-1-1; when the junction temperature is above the upper limit of the preset temperature sampling range, the coolant flow request value for the next cooling operation cycle is X+1; the coolant flow request value for the next cooling operation cycle is X+1+1. The coolant flow request value for any cooling operation cycle will not be less than the minimum cooling water flow limit of 4L / min or greater than the maximum cooling water flow limit of 8L / min.

[0056] S7. When the coolant flow request value reaches the preset maximum coolant flow limit and the junction temperature of the IGBT power module collected within the preset time period is still above the upper limit of the preset temperature sampling range, the preset power reduction protection operation is executed.

[0057] Reference Figure 1-3 The present invention proposes a motor controller coolant flow control system, comprising:

[0058] A data acquisition module is used to collect the junction temperature of the IGBT power module in the motor controller in real time and compare the junction temperature with a preset temperature sampling range;

[0059] A first processing module, for obtaining a basic coolant flow rate related to a current motor speed, motor torque, and bus voltage when the junction temperature exceeds a preset temperature sampling range;

[0060] A second processing module, configured to calculate a coolant flow request value according to a basic coolant flow and a preset cooling control strategy;

[0061] A third processing module, configured to use the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle;

[0062] The execution module is used to repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

[0063] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for controlling the flow rate of coolant in a motor controller, characterized in that: The following steps are involved: S1, collecting the junction temperature of the IGBT power module in the motor controller in real time, and comparing the junction temperature with a preset temperature sampling range; S2. When the junction temperature exceeds the preset temperature sampling range, the basic coolant flow rate related to the current motor speed, motor torque and bus voltage is obtained; S3, calculating a coolant flow request value according to a basic coolant flow and a preset cooling control strategy; S4, using the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle; S5. Repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

2. The motor controller coolant flow control method according to claim 1, characterized in that: The process of obtaining the basic coolant flow rate is as follows: The corresponding basic coolant flow rate is queried from a preset coolant flow rate query database according to the current motor speed, motor torque and bus voltage.

3. The motor controller coolant flow control method according to claim 2, characterized in that: The preset coolant flow query database is pre-configured with multiple coolant flow query tables, and the multiple coolant flow query tables correspond one to one to multiple bus voltage ranges; the coolant flow query table is pre-configured with a mapping relationship between motor speed, motor torque and basic coolant flow, wherein a set of motor speed and motor torque corresponds to a basic coolant flow.

4. The motor controller coolant flow control method according to claim 3, characterized in that: The querying of the corresponding basic coolant flow rate from a preset coolant flow rate query database according to the current motor speed, motor torque and bus voltage specifically includes: Determine a first type of coolant flow query table from a preset coolant flow query database according to the current bus voltage; According to the current motor speed and motor torque, the corresponding basic coolant flow rate is queried from the first type coolant flow rate query table.

5. The motor controller coolant flow control method according to claim 1, characterized in that: The preset cooling control strategy specifically includes: Obtaining a preset cooling threshold value adjusted for each cooling operation cycle; When the junction temperature is below the lower limit of the preset temperature sampling range, the basic coolant flow rate is reduced by a step size equal to the cooling threshold value each time a cooling operation cycle is run under the current working condition to obtain a coolant flow rate request value for the next cooling operation cycle; When the junction temperature is above the upper limit of the preset temperature sampling range, the basic coolant flow rate is increased by a step size equal to the cooling threshold each time a cooling operation cycle is run under the current working condition to obtain the coolant flow rate request value for the next cooling operation cycle.

6. The motor controller coolant flow control method according to claim 1, characterized in that: Also includes: S6. When the coolant flow rate of the motor controller reaches the preset maximum coolant flow rate limit or the minimum coolant flow rate limit, stop repeatedly calculating the coolant flow rate request value; use the maximum coolant flow rate limit or the minimum coolant flow rate limit as the coolant flow rate of the motor controller in the subsequent cooling operation cycle; until the collected junction temperature of the IGBT power module meets the preset temperature sampling range, execute the coolant flow rate value of the motor controller corresponding to the preset temperature sampling range.

7. The motor controller coolant flow control method according to claim 1, characterized in that: Before step S1, the method further includes: Build a coolant flow query database; The bus voltage range is divided into a plurality of bus voltage range segments, and a coolant flow query table is constructed correspondingly to the plurality of bus voltage range segments; A plurality of sets of motor speeds and motor torques and a plurality of basic coolant flow rates are configured in the coolant flow query table, wherein a set of motor speeds and motor torques corresponds to a basic coolant flow rate.

8. The motor controller coolant flow control method according to claim 1, characterized in that: Also includes: S7. When the coolant flow request value reaches the preset maximum coolant flow limit and the junction temperature of the IGBT power module collected within a preset time period is still above the upper limit of the preset temperature sampling range, a preset power reduction protection operation is performed.

9. A motor controller coolant flow control system, characterized in that: include: A data acquisition module is used to collect the junction temperature of the IGBT power module in the motor controller in real time and compare the junction temperature with a preset temperature sampling range; A first processing module, for obtaining a basic coolant flow rate related to a current motor speed, motor torque, and bus voltage when the junction temperature exceeds a preset temperature sampling range; A second processing module, configured to calculate a coolant flow request value according to a basic coolant flow and a preset cooling control strategy; A third processing module, configured to use the coolant flow request value as the coolant flow of the motor controller in the next cooling operation cycle; The execution module is used to repeat steps S1-S4 according to the cooling operation cycle to update the coolant flow of the motor controller until the collected junction temperature of the IGBT power module meets the preset temperature sampling range.

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