Water channel control system and control method for double inverters

Abstract

The invention provides a water channel control system and method for double inverters, and the system comprises a first inverter, a second inverter, a first liquid inlet pipeline, a second liquid inlet pipeline, a third liquid inlet pipeline, a fourth liquid inlet pipeline, a first valve, a second valve, and a control unit. A first valve is arranged on the third liquid inlet pipeline and electrically connected with the control unit, a second valve is arranged on the fourth liquid inlet pipeline and electrically connected with the control unit, and the control unit can control opening and closing of the first valve and the second valve. According to the water channel control system and control method for the double inverters, different cooling requirements of the double inverters under different working conditions can be met, the situation that the power of the inverters is limited due to insufficient heat dissipation is avoided, and vehicle performance and economic benefits are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle power, and particularly relates to a water channel control system and a control method for a dual inverter. Background Art

[0002] Semiconductor power devices in high-power inverters carry high power / large current, and generate a large amount of heat due to power loss. Vehicle-mounted inverters generally use water cooling to remove heat. In the design of vehicle-mounted dual inverters, a fixed water channel design is often shared by two inverters to simplify the structure. The disadvantage of this design is that it can only be set for one relatively harsh working condition among many working conditions of the two motor inverters, lacking the flexibility of heat dissipation.

[0003] For example, if the vehicle-mounted dual inverters are respectively denoted as A and B, if there are two working conditions, in the first working condition, the power of inverter A is P A1 , the power that the coolant needs to take away is P lossA1 , the power of inverter B is P B1 , the power that the coolant needs to take away is P lossB1 , in the second working condition, the power of inverter A is P A2 , the power that the coolant needs to take away is P lossA2 , the power of inverter B is P B2 , the power that the coolant needs to take away is P lossB2 , assuming P lossA1 >P lossA2 and P lossB1 <P lossB2 , since currently two inverters share a set of coolant inlet and outlet water channels, there are three design ideas when designing the coolant flow rate:

[0004] If designed according to the first working condition P lossA1 +P lossB1 , it may not meet the cooling requirement of the second working condition P los sA2 +P lossB2 ; if designed according to the second working condition P lossA2 +P lossB2 , it may not meet the cooling requirement of the first working condition P lossA1 +P lossB1 . In both of the above cases, there is a situation where the power of a certain inverter is limited due to insufficient heat dissipation, ultimately affecting the vehicle performance.

[0005] If designed according to the cooling requirements of both working conditions P lossA1 +P lossB2 , it will lead to over-design and increased costs. Summary of the Invention

[0006] In view of the above problems, the present invention provides a water channel control system and a control method for a dual-inverter, which can solve one or more of the above technical problems.

[0007] According to one aspect of the present invention, there is provided a water channel control system for a dual-inverter, comprising:

[0008] a first inverter, a second inverter, a first liquid inlet pipe, a second liquid inlet pipe, a third liquid inlet pipe, a fourth liquid inlet pipe, a first valve, a second valve, and a control unit,

[0009] The first liquid inlet pipe and the third liquid inlet pipe are for the coolant to flow into the first inverter,

[0010] The second liquid inlet pipe and the fourth liquid inlet pipe are for the coolant to flow into the second inverter,

[0011] A first valve is provided on the third liquid inlet pipe, and the first valve is electrically connected to the control unit, and the control unit can control the opening and closing of the first valve.

[0012] A second valve is provided on the fourth liquid inlet pipe, and the second valve is electrically connected to the control unit, and the control unit can control the opening and closing of the second valve.

[0013] The first valve and the second valve are not both open at the same time and are not both closed at the same time.

[0014] In some embodiments, the sum of the coolant flow rates Q of the first liquid inlet pipe and the third liquid inlet pipe flowing into the first inverter A can meet the maximum cooling requirements of the first inverter under various working conditions; the sum of the coolant flow rates Q of the second liquid inlet pipe and the fourth liquid inlet pipe flowing into the second inverter B can meet the maximum cooling requirements of the second inverter under various working conditions.

[0015] In some embodiments, the coolant flow rate △Q of the third liquid inlet pipe A can meet the maximum value among the differences in the cooling requirements of the first inverter under various working conditions, and the coolant flow rate of the first liquid inlet pipe is Q A1 , Q A =△Q A +Q A1 .

[0016] In some embodiments, the coolant flow rate △Q of the fourth liquid inlet pipe B can meet the maximum value among the differences in the cooling requirements of the second inverter under various working conditions, and the coolant flow rate of the second liquid inlet pipe is Q B1 , Q B =△Q B +Q B1 .

[0017] In some embodiments, the coolant flow rate allowed to pass through the third liquid inlet pipe is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe, denoted as ΔQ.

[0018] In some embodiments, when the coolant flow rate allowed to pass through the third liquid inlet pipe is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe, let ΔQ = max{ΔQ A , ΔQ B}, and ΔQ can meet the maximum value among the differences in cooling requirements for each operating condition of the second inverter and the differences in cooling requirements for each operating condition of the first inverter.

[0019] According to another aspect of the present invention, there is provided a water channel control method for a dual inverter, applying any of the above water channel control systems for a dual inverter, including the following steps:

[0020] The control unit judges the cooling requirements of the first inverter and the second inverter according to the current operating condition.

[0021] The control unit controls the opening and closing of the first valve and the second valve according to the cooling requirements of the first inverter and the second inverter. When the cooling requirement of the first inverter is greater than that of the second inverter, the sum of the coolant flowing into the first inverter from the first liquid inlet pipe and the third liquid inlet pipe meets the cooling requirement of the first inverter. When the cooling requirement of the second inverter is greater than that of the first inverter, the sum of the coolant flowing into the second inverter from the second liquid inlet pipe and the fourth liquid inlet pipe meets the cooling requirement of the second inverter.

[0022] In some embodiments, the sum of the coolant flow rates Q A of the first liquid inlet pipe and the third liquid inlet pipe can meet the maximum cooling requirement of the first inverter under various operating conditions; the sum of the coolant flow rates Q B of the second liquid inlet pipe and the fourth liquid inlet pipe flowing into the second inverter can meet the maximum cooling requirement of the second inverter under various operating conditions.

[0023] The beneficial effects of the present invention are as follows: Through the settings of the third liquid inlet pipe, the fourth liquid inlet pipe, the first valve and the second valve, the control unit controls the opening and closing of the first valve and the second valve, and then controls the on-off of the third liquid inlet pipe and the fourth liquid inlet pipe, adjusts the coolant flow rate according to the cooling requirements under the actual operating conditions, can meet the different cooling requirements of the dual inverter under different operating conditions, avoid power limitation of the inverter due to insufficient heat dissipation, improve vehicle performance; the structure is simple, the cost is low, and it can be widely applied in the field of new energy vehicle power systems, including but not limited to range-extended new energy vehicles, pure electric vehicles, plug-in hybrid vehicles, and any occasions where dual inverter controllers are used.

[0024] In addition, in the technical solution of the present invention, unless otherwise specified, the present technical solution can be implemented by adopting conventional means in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the drawings required for the description of the specific embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 FIG. is a schematic structural diagram of a water channel control system for a dual inverter provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are some, but not all, embodiments of the present invention, and are only used to explain the present invention, not to limit the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or server that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0029] Embodiment 1:

[0030] Refer to the attached drawings of the specification Figure 1 , which shows a water channel control system for a dual inverter provided by an embodiment of the present invention, including:

[0031] A first inverter 1, a second inverter 2, a first liquid inlet pipe 3, a second liquid inlet pipe 4, a third liquid inlet pipe 5, a fourth liquid inlet pipe 6, a first valve 7, a second valve 8 and a control unit,

[0032] The first liquid inlet pipe 3 and the third liquid inlet pipe 5 are used to allow the coolant to flow into the first inverter 1,

[0033] The second liquid inlet pipe 4 and the fourth liquid inlet pipe 6 are used to allow the coolant to flow into the second inverter 2,

[0034] A first valve 7 is provided on the third liquid inlet pipeline 5. The first valve 7 is electrically connected to the control unit, and the control unit can control the opening and closing of the first valve 7.

[0035] The state of the first valve 7 is fully open or fully closed, without any other intermediate states.

[0036] A second valve 8 is provided on the fourth liquid inlet pipeline 6. The second valve 8 is electrically connected to the control unit, and the control unit can control the opening and closing of the second valve 8.

[0037] The state of the second valve 8 is fully open or fully closed, without any other intermediate states.

[0038] The opening and closing relationship between the first valve 7 and the second valve 8 is an exclusive OR relationship, that is, the first valve 7 and the second valve 8 cannot be open at the same time, and the first valve 7 and the second valve 8 cannot be closed at the same time.

[0039] In an alternative embodiment, one end of the first liquid inlet pipeline 3 and the third liquid inlet pipeline 5 is connected to the water inlet of the cooling water channel of the first inverter 1, and the other end can be connected to the coolant inflow pipeline 9. The coolant inflow pipeline 9 can be connected to the liquid outlet of the cooling pump.

[0040] One end of the second liquid inlet pipeline 4 and the fourth liquid inlet pipeline 6 is connected to the water inlet of the cooling water channel of the second inverter 2, and the other end can be connected to the coolant inflow pipeline 9. The coolant inflow pipeline 9 can be connected to the liquid outlet of the cooling pump.

[0041] Refer to the attached Figure 1 in the specification. The coolant inflow direction is as shown by the arrow in the attached drawing.

[0042] In an alternative embodiment, the sum of the coolant flow rates Q of the first liquid inlet pipeline 3 and the third liquid inlet pipeline 5 flowing into the first inverter 1 A should be able to meet the maximum cooling requirements of the first inverter 1 under various working conditions; the sum of the coolant flow rates Q of the second liquid inlet pipeline 4 and the fourth liquid inlet pipeline 6 flowing into the second inverter 2 B should be able to meet the maximum cooling requirements of the second inverter 2 under various working conditions. The flow rate Q of the coolant inflow pipeline 9 should be equal to the sum of Q A and Q B .

[0043] The coolant flow rate Q of the first liquid inlet pipeline 3 flowing into the first inverter 1 A1 should be able to meet the minimum cooling requirements of the first inverter 1 under various working conditions. The coolant flow rate Q of the second liquid inlet pipeline 4 flowing into the second inverter 2 B1 should be able to meet the minimum cooling requirements of the second inverter 2 under various working conditions.

[0044] For example, the vehicle has two working conditions:

[0045] In the first working condition, the power of the first inverter 1 is P A1 , and the power loss that the coolant needs to carry away is P lossA1 , and the power of the second inverter 2 is P B1 , and the power loss that the coolant needs to carry away is P lossB 1;

[0046] In the second working condition, the power of the first inverter 1 is P A2 , and the power loss that the coolant needs to carry away is P lossA2 , and the power of the second inverter 2 is P B2 , and the power loss that the coolant needs to carry away is P lossB 2.

[0047] At this time, the flow rate Q A should satisfy the requirement of being able to carry away the power loss P lossAMAX = max(P lossA1 , P lossA2 ), that is, the value of Q A should be able to meet the maximum cooling requirement of the first inverter 1 under all working conditions of the vehicle; the flow rate Q B should satisfy the requirement of being able to carry away the power loss P lossBMAX = max(P lossB1 , P los sB2 ), that is, the value of Q B should be able to meet the maximum cooling requirement of the second inverter 2 under all working conditions of the vehicle.

[0048] In an alternative embodiment, the coolant flow rate △Q of the third liquid inlet pipe 5 A can meet the maximum value among the differences in the cooling requirements of the first inverter 1 under various working conditions, and the coolant flow rate of the first liquid inlet pipe 3 is Q A - △Q A ; the coolant flow rate △Q of the fourth liquid inlet pipe 6 B can meet the maximum value among the differences in the cooling requirements of the second inverter 2 under various working conditions, and the coolant flow rate of the second liquid inlet pipe 4 is Q B - △Q B .

[0049] Taking the vehicle having two working conditions as an example, in the first working condition, the power of the first inverter 1 is P A1 , and the power that the coolant needs to carry away is P lossA1 , and the power of the second inverter 2 is P B1 , and the power that the coolant needs to carry away is P lossB1 ; in the second working condition, the power of the first inverter 1 is P A2 , and the power that the coolant needs to carry away is P lossA2, the power of the second inverter 2 is P B2 , the power that the coolant needs to carry away is P lossB2 .

[0050] Since there are only two working conditions in this example, so △Q A is the flow rate corresponding to △P lossA = abs(P lossA1 - P lossA2 ), where abs means taking the absolute value of the operation result inside the parentheses. △Q B is the flow rate corresponding to △P lossB = abs(P lossB1 - P lossB2 ). Assume P lossA1 >P lossA2 and P lossB1 <P lossB2 , then Q A 1 is the flow rate corresponding to P lossA2 , △Q A is the flow rate corresponding to △P lossA = P lossA1 - P lossA2 , Q B1 is the flow rate corresponding to P lossB1 , △Q B is the flow rate corresponding to △P lossB = P lossB2 - P lossB1 .

[0051] When the vehicle is in the first working condition, the flow rate of the first liquid inlet pipe 3 is Q A1 , corresponding to the power loss P lossA2 , the coolant flow rate of the second liquid inlet pipe 4 is Q B1 , corresponding to the power loss P lossB1 , since P lossA1 >P lossA2 , at this time, if the first valve 7 is closed, the cooling requirement of the first inverter 1 cannot be met. Therefore, the control unit will control the first valve 7 to open, and the total coolant flow rate flowing into the first inverter 1 from the first liquid inlet pipe 3 and the third liquid inlet pipe 5 is Q A to carry away the heat generated by P lossA1 and meet the cooling requirement of the first inverter 1 under the first working condition. And since the coolant flow rate flowing into the second inverter 2 from the second liquid inlet pipe 4 is Q B1 corresponding to the power loss P lossB1 , it can directly meet the cooling requirement of the second inverter 2 under the first working condition. Therefore, the control unit will control the second valve 8 to close. Such a flow rate arrangement can meet the cooling requirements of the first inverter 1 and the second inverter 2 under the first working condition at the same time.

[0052] When the vehicle is in the second working condition, the flow rate of the first liquid inlet pipe 3 is Q A1 , that is, corresponding to the power loss P lossA2 , the coolant flow rate of the second liquid inlet pipe 4 is Q B1 , that is, corresponding to the power loss P lossB1 , since P lossA1 >P lossA2 and P lossB1 <P lossB2 , at this time, the coolant flow rate flowing into the first inverter 1 through the first liquid inlet pipe 3 can meet the cooling requirement of the first inverter 1 under the second working condition. Therefore, the control unit will control the first valve 7 to close. However, at this time, only the coolant flow rate flowing into the second inverter 2 through the second liquid inlet pipe 4 cannot meet the cooling requirement of the second inverter 2. The control unit will control the second valve 8 to open. The total coolant flow rate flowing into the first inverter 1 through the second liquid inlet pipe 4 and the fourth liquid inlet pipe 6 is Q B , that is, corresponding to the power loss P lossB2 , which can meet the cooling requirement of the second inverter 2 under the second working condition.

[0053] When the vehicle working condition is more complex, assume there is a third working condition. The power of the first inverter 1 is P A3 , and the power that the coolant needs to take away is P lossA3 , the power of the second inverter 2 is P B3 , and the power that the coolant needs to take away is P lossB3 , at this time, △Q A is the flow rate corresponding to △P lossA =max(abs(P lossA1 -P lossA2 ), abs(P lossA1 -P lossA3 ), abs(P lossA2 -P lossA3 ))). △Q B is the flow rate corresponding to △P lossB =max(abs(P lossB1 -P lossB2 ), abs(P lossB1 -P lossB3 ), abs(P lossB2 -P lossB3 ))). That is, △Q A is the maximum value of the absolute differences between the cooling requirements of the first inverter 1 under each working condition in pairs, and △Q B is the maximum value of the absolute differences between the cooling requirements of the second inverter 2 under each working condition in pairs.

[0054] In an alternative embodiment, the coolant flow rate allowed to pass through the third liquid inlet pipe 5 is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe 6, denoted as △Q. When the coolant flow rate allowed to pass through the third liquid inlet pipe 5 is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe 6, let △Q = max{△Q A , △Q B}, that is, △Q can meet the maximum value of the difference in cooling requirements for each operating condition of the second inverter and the difference in cooling requirements for each operating condition of the first inverter.

[0055] For example, the third liquid inlet pipe 5 and the fourth liquid inlet pipe 6 can be connected to the coolant inlet pipe 9 by a tee fitting. At this time, the coolant flow rate allowed to pass through the third liquid inlet pipe 5 and the fourth liquid inlet pipe 6 is equal, both being △Q. Since △Q = max{△Q A , △Q B} at this time, taking the above two operating conditions as an example, △Q is the flow rate corresponding to △P lossMAX = max(abs(P lossA1 - P lossA2 ), abs(P lossB1 - P lossB2 ))), that is, the value of △Q should be the maximum value of the absolute differences between the cooling requirements of the first inverter 1 for each pair of operating conditions and the absolute differences between the cooling requirements of the second inverter 2 for each pair of operating conditions.

[0056] When the vehicle is in the first operating condition, the coolant flow rate of the first liquid inlet pipe 3 is Q A1 , the coolant flow rate of the second liquid inlet pipe 4 is Q B1 . Assuming P lossA1 > P lossA2 and P lossB1 < P lossB2 , abs(P los sB1 - P lossB2 ) > abs(P lossA1 - P lossA2 ), Q A1 corresponds to the power loss P lossA2 , Q B1 corresponds to the power loss P lossB1 , △Q is the flow rate corresponding to △P lossMAX = max{abs(P lossA1 - P lossA2 ), abs(P lossB1 - P lossB2 )}. It is known that abs(P lossB1 - P lossB2 ) > abs(P lossA1 - P lossA2 ), then △Q is P lossB2 - PlossB1 The corresponding flow rate. At this time, the coolant flow rate of the first liquid inlet pipe 3 cannot meet the cooling requirements under the first working condition. Therefore, the control unit will control the first valve 7 to open. At this time, △Q is greater than P lossA1 -P lossA2 The corresponding flow rate. Therefore, the sum of the coolant flow rates of the first liquid inlet pipe 3 and the third liquid inlet pipe 5, Q A =Q A1 +△Q, must be greater than P lossA1 The corresponding coolant flow rate, meeting the cooling requirements of the first inverter 1 under the first working condition. The coolant flow rate Q of the second liquid inlet pipe 4 B 1 corresponds to the power loss P lossB1 , directly meeting the cooling requirements of the second inverter 2 under the first working condition.

[0057] When the vehicle is in the second working condition, the coolant flow rate of the first liquid inlet pipe 3 is Q A1 , and the coolant flow rate of the second liquid inlet pipe 4 is Q B1 , P lossA1 >P lossA2 and P lossB1 <P lossB2 , abs(P lossB1 -P l ossB2 )>abs(P lossA1 -P lossA2 ), Q A1 corresponds to the power loss P lossA2 , Q B1 corresponds to the power loss P l ossB1 , △Q is the flow rate corresponding to △P lossMAX =max{abs(P lossA1 -P lossA2 ), abs(P lossB1 -P lossB2 )}, since abs(P lossB1 -P lossB2 )>abs(P lossA1 -P lossA2 ), then △Q is the flow rate corresponding to P lossB2 -P lossB1 . At this time, the coolant flow rate Q of the first liquid inlet pipe 3 flowing into the first inverter 1 A1 corresponds to P lossA2 , meeting the cooling requirements of the first inverter 1 under the second working condition. The first valve 7 is closed, and the coolant flow rate Q of the second liquid inlet pipe 4 flowing into the second inverter 1 B1 cannot meet P lossB2For the corresponding cooling requirement, the control unit controls the second valve 8 to open, and the total coolant flow rate Q flowing into the first inverter 1 from the second liquid inlet pipe 4 and the fourth liquid inlet pipe 6 B = Q B1 + △Q, that is, P lossB1 +(P lossB2 - P lossB1 ) corresponding coolant flow rate can meet the cooling requirement of the second inverter 2 under the second working condition.

[0058] The beneficial effects of the present invention are as follows: By setting the third liquid inlet pipe, the fourth liquid inlet pipe, the first valve and the second valve, the control unit controls the opening and closing of the first valve and the second valve, and then controls the on-off of the third liquid inlet pipe and the fourth liquid inlet pipe, and adjusts the coolant flow rate according to the cooling requirement under the actual working condition, which can not only meet the different cooling requirements of the dual inverters under different working conditions, avoid the power limitation of the inverter due to insufficient heat dissipation, and improve the vehicle performance; the structure is simple, the cost is low, and it can be widely applied to the field of new energy vehicle power systems, including but not limited to range-extended new energy vehicles, pure electric vehicles, plug-in hybrid vehicles, and any occasions where dual inverter controllers are used.

[0059] Embodiment 2:

[0060] An embodiment of the present invention further provides a water channel control method for a dual inverter, applying a water channel control system for a dual inverter according to any one of the above embodiments. The method includes:

[0061] The control unit judges the cooling requirements of the first inverter and the second inverter according to the current working condition,

[0062] The control unit controls the opening and closing of the first valve and the second valve according to the cooling requirements of the first inverter and the second inverter. When the cooling requirement of the first inverter is greater than that of the second inverter, the sum of the coolant flowing into the first inverter from the first liquid inlet pipe and the third liquid inlet pipe satisfies the cooling requirement of the first inverter. When the cooling requirement of the second inverter is greater than that of the first inverter, the sum of the coolant flowing into the second inverter from the second liquid inlet pipe and the fourth liquid inlet pipe satisfies the cooling requirement of the second inverter.

[0063] In an optional embodiment, the sum of the coolant flow rates Q of the first liquid inlet pipe and the third liquid inlet pipe A can meet the maximum cooling requirement of the first inverter under various working conditions; the sum of the coolant flow rates Q flowing into the second inverter from the second liquid inlet pipe and the fourth liquid inlet pipe B can meet the maximum cooling requirement of the second inverter under various working conditions.

[0064] Other contents identical to those in Embodiment 1 will not be elaborated.

[0065] The beneficial effects of the present invention are as follows: Through the setting of the third liquid inlet pipe, the fourth liquid inlet pipe, the first valve and the second valve, the control unit controls the opening and closing of the first valve and the second valve, thereby controlling the on-off of the third liquid inlet pipe and the fourth liquid inlet pipe, and adjusting the coolant flow according to the cooling requirements under actual working conditions. It can not only meet the different cooling requirements of the dual inverters under different working conditions, avoid power limitation of the inverter due to insufficient heat dissipation, improve vehicle performance, but also avoid waste of coolant and power, and improve the environmental performance and economic benefits of the vehicle; The structure is simple, the cost is low, and it can be widely applied to the field of new energy vehicle power systems, including but not limited to range-extended new energy vehicles, pure electric vehicles, plug-in hybrid vehicles, and any occasions where a dual inverter controller is used.

[0066] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A water channel control system for a dual inverter, characterized in that, Comprising: A first inverter, a second inverter, a first liquid inlet pipe, a second liquid inlet pipe, a third liquid inlet pipe, a fourth liquid inlet pipe, a first valve, a second valve, and a control unit. The first liquid inlet pipe and the third liquid inlet pipe are for coolant to flow into the first inverter. The second liquid inlet pipe and the fourth liquid inlet pipe are for coolant to flow into the second inverter. A first valve is provided on the third liquid inlet pipe. The first valve is electrically connected to the control unit, and the control unit can control the opening and closing of the first valve. A second valve is provided on the fourth liquid inlet pipe. The second valve is electrically connected to the control unit, and the control unit can control the opening and closing of the second valve. The first valve and the second valve are not both open at the same time and are not both closed at the same time.

2. The water channel control system for a dual inverter according to claim 1, wherein: The sum Q of the coolant flow rates flowing into the first inverter through the first liquid inlet pipe and the third liquid inlet pipe A can meet the maximum cooling requirements of the first inverter under various working conditions; the sum Q of the coolant flow rates flowing into the second inverter through the second liquid inlet pipe and the fourth liquid inlet pipe B can meet the maximum cooling requirements of the second inverter under various working conditions.

3. The water channel control system for a dual inverter according to claim 1, wherein: The coolant flow rate △Q of the third liquid inlet pipe A can meet the maximum value among the differences in cooling requirements under various operating conditions of the first inverter. The coolant flow rate of the first liquid inlet pipe is Q A1 , Q A = △Q A + Q A1 .

4. The water channel control system for a dual inverter according to claim 1, wherein: The coolant flow rate ΔQ of the fourth liquid inlet pipe B can meet the maximum value among the differences in cooling requirements under various working conditions of the second inverter. The coolant flow rate of the second liquid inlet pipe is Q B1 , Q B = ΔQ B + Q B1 .

5. The water channel control system for a dual inverter according to claim 1, wherein: The coolant flow rate allowed to pass through the third liquid inlet pipe is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe, denoted as △Q.

6. The water channel control system for a dual inverter according to claim 5, wherein: When the coolant flow rate allowed to pass through the third liquid inlet pipe is equal to the coolant flow rate allowed to pass through the fourth liquid inlet pipe, let △Q = max{△Q A , △Q B}, and △Q can meet the maximum value of the difference in cooling requirements for each working condition of the second inverter and the difference in cooling requirements for each working condition of the first inverter.

7. A water channel control method for a dual inverter, which is applied to a water channel control system for a dual inverter according to any one of claims 1-6, characterized in that, Comprising: The control unit judges the cooling requirements of the first inverter and the second inverter according to the current working conditions. The control unit controls the opening and closing of the first valve and the second valve according to the cooling requirements of the first inverter and the second inverter. When the cooling requirement of the first inverter is greater than that of the second inverter, the sum of the coolant flowing into the first inverter through the first liquid inlet pipe and the third liquid inlet pipe satisfies the cooling requirement of the first inverter. When the cooling requirement of the second inverter is greater than that of the first inverter, the sum of the coolant flowing into the second inverter through the second liquid inlet pipe and the fourth liquid inlet pipe satisfies the cooling requirement of the second inverter.

8. The water channel control method for a dual inverter according to claim 7, wherein: The sum Q of the coolant flow rates of the first liquid inlet pipe and the third liquid inlet pipe A can meet the maximum cooling requirements of the first inverter under various working conditions; the sum Q of the coolant flow rates flowing into the second inverter through the second liquid inlet pipe and the fourth liquid inlet pipe B can meet the maximum cooling requirements of the second inverter under various working conditions.

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