Self-adaptive thermal management method and system for IGCT-MMC flexible DC submodule

Abstract

The invention discloses a self-adaptive thermal management method and system for an IGCT-MMC flexible DC submodule, and the method comprises the steps: enabling a plurality of IGCT power devices to be connected in series in a mechanical crimping manner, and guaranteeing the reliable electrical connection; each IGCT is provided with a corresponding water-cooling radiator, adopts a micro-channel or cold plate structure and is controlled by a flow dynamic adjusting device; and the port current of the sub-module and the water inlet temperature of cooling water are collected in real time, and the flow of the water-cooling radiator is controlled. The system comprises an association setting unit and a dynamic adjusting unit. According to the invention, thermal management can be carried out on the premise of not changing system output, and continuous and consistent operation of the system is facilitated. The method can be widely applied to the field of flexible direct-current power transmission.

Description

Technical Field

[0001] The present invention relates to the field of flexible direct current (DC) transmission, and in particular to an adaptive thermal management method and system for an IGCT-MMC flexible DC submodule. Background Art

[0002] Thanks to their high voltage, large capacity, and high reliability, IGCT devices have broad application prospects in flexible DC transmission. Compared to IGBTs, IGCTs have lower conduction losses but slightly higher turn-off losses. In terms of overall losses, IGCTs are slightly superior to IGBTs.

[0003] During operation, the working state of IGCT devices is affected by various factors, especially temperature. How to keep the power devices in the sub-module in the optimal heat dissipation state without affecting the system heat dissipation system is a problem that industry personnel have been studying. The current methods are mostly to control the temperature in the device by adjusting the system power. This operation will reduce the normal operation time of the IGCT device and increase the working cost. Summary of the Invention

[0004] In view of this, in order to solve the technical problem that existing submodule thermal management methods cannot adjust the temperature of the submodule without affecting the system heat dissipation system, thereby leading to high operating costs of IGCT devices, in a first aspect, the present invention proposes an adaptive thermal management method for an IGCT-MMC flexible direct current submodule, the method comprising the following steps:

[0005] Multiple IGCT power devices are connected in series through mechanical crimping to ensure reliable electrical connection; each IGCT is equipped with a corresponding water-cooled radiator, which adopts a micro-channel or cold plate structure and is controlled by a dynamic flow adjustment device;

[0006] The submodule's port current and cooling water inlet temperature are collected in real time, and the flow rate to the water-cooled radiator is controlled. The purpose of flow control is to ensure that each power device operates within the allowable junction temperature range and minimize flow output. The two main parameters required for control are the submodule port current and the cooling water inlet temperature. If the submodule port current increases or the cooling water inlet temperature rises, the junction temperature of the corresponding power device in the submodule will increase. In this case, the cooling water flow rate to the corresponding radiator must be increased to ensure the junction temperature remains within the allowable range. If the submodule port current decreases or the cooling water inlet temperature drops, the junction temperature of the corresponding power device in the submodule will decrease. In this case, the cooling water flow rate to the corresponding radiator can be reduced to reduce pump consumption and improve system energy efficiency.

[0007] In some embodiments, the IGCT-MMC flexible direct current submodule includes an upper tube IGCT device, an upper tube freewheeling diode, a lower tube IGCT device, a lower tube freewheeling diode, a DC capacitor, an anode reactance and a clamping circuit, wherein the clamping circuit includes a clamping diode, a clamping resistor and a clamping capacitor.

[0008] In a second aspect, the present invention further proposes an adaptive thermal management system for an IGCT-MMC flexible submodule, the system comprising:

[0009] The association setting unit is used to connect multiple IGCT power devices in series into groups through mechanical crimping to ensure reliable electrical connection; each IGCT is equipped with a corresponding water-cooled radiator, which adopts a microchannel or cold plate structure and is controlled by a dynamic flow adjustment device;

[0010] The dynamic adjustment unit is used to collect the port current and cooling water inlet temperature of the submodule in real time and control the flow of the water-cooled radiator.

[0011] Based on the above scheme, the present invention provides an adaptive thermal management method and system for an IGCT-MMC flexible direct current submodule. By collecting the submodule port current and water inlet temperature, combined with the radiator's own characteristics and the submodule water path structure, the submodule water system is dynamically adjusted to ensure that the power devices in the submodule are in the optimal heat dissipation state, thereby enabling the IGCT-MMC flexible direct current submodule to be in a stable working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a flowchart of the steps of an adaptive thermal management method for an IGCT-MMC flexible direct current submodule of the present invention;

[0013] Figure 2 1 is a topological structure diagram of the IGCT-MMC flexible direct current submodule according to a specific embodiment of the present invention;

[0014] Figure 3 Schematic diagram of the crimping of the IGCT-MMC flexible direct current submodule according to a specific embodiment of the present invention;

[0015] Figure 4 is a graph showing the relationship between the coolant flow rate and the thermal resistance of the plate surface in a specific embodiment of the present invention;

[0016] Figure 5 is a graph showing the relationship between the coolant flow rate and the plate surface flow resistance in a specific embodiment of the present invention;

[0017] Figure 6 This is a structural block diagram of an adaptive thermal management system for an IGCT-MMC flexible submodule of the present invention;

[0018] Reference numerals: S1, upper tube IGCT device; D1, upper tube freewheeling diode; S2, lower tube IGCT device; D2, lower tube freewheeling diode; C, DC capacitor; L i , anode reactance; D CL , clamping diode; R S , clamping resistor; C CL , clamping capacitor. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0020] It should be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0021] It should be understood that the terms "system," "device," "unit," and / or "module" used in this application are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0022] As used in this application and the claims, unless the context clearly indicates an exception, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular and may include the plural, unless the context clearly indicates otherwise. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements. The phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, product, or apparatus that includes the elements.

[0023] In the description of the embodiments of this application, "plurality" refers to two or more than two. The terms "first" and "second" below are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0024] In addition, flow charts are used in this application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0025] Reference Figure 1 , which is a flow chart of an optional example of the adaptive thermal management method of the IGCT-MMC flexible direct current submodule proposed in the present invention, and the method can be applied to computer equipment.

[0026] The thermal management method proposed in this embodiment is applied to Figure 2 and Figure 3 The IGCT-MMC flexible submodule is shown.

[0027] like Figure 2 As shown, the IGCT-MMC flexible direct current submodule includes an upper tube IGCT device, an upper tube freewheeling diode, a lower tube IGCT device, a lower tube freewheeling diode, a DC capacitor, an anode reactance, a clamping diode, a clamping resistor and a clamping capacitor, wherein:

[0028] The first end of the upper tube IGCT device, the second end of the upper tube freewheeling diode, the first end of the clamping diode and the first end of the anode reactance are connected; the second end of the upper tube IGCT device, the first end of the upper tube freewheeling diode, the first end of the lower tube IGCT device and the second end of the lower tube freewheeling diode are connected; the second end of the lower tube IGCT device, the first end of the lower tube freewheeling diode, the first end of the clamping capacitor and the first end of the DC capacitor are connected; the second end of the DC inductor clamping diode, the first end of the clamping resistor and the second end of the clamping capacitor are connected; the second end of the anode reactance, the second end of the clamping resistor and the second end of the DC capacitor are connected.

[0029] like Figure 3 As shown in the figure, the power devices of the IGCT-MMC flexible direct current submodule are pressed into a string through a water-cooled radiator. The water inlet of the radiator flows through all radiators and then flows out. A flow dynamic adjustment device is set at the water inlet of the radiator. The device can control the diversion ratio k(0 <k<1)。

[0030] The thermal management method proposed in this embodiment may include but is not limited to the following steps:

[0031] Step S1: crimp the power devices of the IGCT-MMC flexible direct current submodule into a string, and equip each power device with a corresponding water-cooling radiator;

[0032] Step S2: dynamically adjust the flow rate of the water-cooled radiator according to the port current and the inlet water temperature of the IGCT-MMC flexible direct current submodule.

[0033] The power devices in the submodule have different losses when operating in different modes. The losses can be determined by calculation and actual measurement. In the rectification and inversion modes, the losses of each device are directly related to the bridge arm current:

[0034]

[0035] The heat of the power devices is mainly dissipated through the submodule water cooling system. Since the power devices in the IGCT-MMC all use double-sided heat dissipation and the power distribution on both sides is uniform, and the junction-to-case thermal resistance and contact thermal resistance of the power devices are fixed, the junction temperature of each power device can be expressed as:

[0036]

[0037] R th(S1，S2，D1，D2，DCL) =R th-JC(S1，S2，D1，D2，DCL) +R th-CH(S1，S2，D1，D2，DCL) +R th-sink

[0038] in, Indicates the junction temperature of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the inverter mode, T in Indicates the submodule inlet water temperature, Indicates the losses of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the inverter mode. It represents the total thermal resistance of the upper tube IGCT device, the lower tube IGCT device, the upper tube freewheeling diode, the lower tube freewheeling diode and the clamping diode. Indicates the junction temperature of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the rectification mode. Indicates the losses of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the rectification mode. It represents the junction-to-case thermal resistance of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode. R represents the contact thermal resistance of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode. th-sink Indicates the thermal resistance of the water cooling radiator

[0039] Among them, Figure 4 As shown, the relationship between the heat sink thermal resistance and the flow rate x is:

[0040] R th-sink =10.523×x -0.547

[0041] Then the above formula can be expressed as:

[0042]

[0043] In order to ensure that the change of water flow in the submodule does not affect the system, its flow resistance P sm Should remain unchanged, the relationship between flow resistance and flow rate x is:

[0044] P sm =P H1 +P H2 ....+P H6

[0045] Among them Figure 5 As shown, P H The flow resistance of each radiator is related to the water flow rate as follows:

[0046] P H =0.6458×x 1.9992

[0047] Substituting in:

[0048] P sm =0.6458×x1 1.9992 +0.6458×x2 1.9992 .....+0.6458×x6 1.9992

[0049] Specifically, taking an IGCT-MMC flexible direct current submodule based on a 6.5kVIGCT device in rectification mode as an example, the submodule has a flow resistance design value of 0.13MPa and a water flow design value of 14L / min. The submodule has a total of 6 radiators, of which the water flow rates of H1, H2, and H3 are (14×k)L / min, and the water flow rates of H4, H5, and H6 are (14×(1-k))L / min.

[0050] By monitoring the submodule port current, we can substitute it into the fitting curve to obtain the loss of the upper tube power device. By substituting the water inlet temperature, we can obtain the junction temperature of each power device:

[0051]

[0052] The submodule flow resistance needs to meet the following requirements:

[0053] P sm =3×0.6458×(14×k) 1.9992 +3×0.6458×(14×(1-k)) 1.9992 =0.13×10 3

[0054] Combined with the junction temperature limit of the power device, the k value is optimized using the following formula:

[0055]

[0056] Based on the simulation experiments conducted on the above scheme, the application of IGCT-MMC in the field of flexible DC transmission can not only improve the localization level of transmission equipment, but also provide new ideas for the selection of power devices for flexible DC transmission. The use of adaptive thermal management methods can further improve the operating reliability of IGCT-MMC, and also lay the foundation for increasing the operating voltage of IGCT flexible DC sub-modules.

[0057] like Figure 6 As shown, an adaptive thermal management system for an IGCT-MMC flexible direct current submodule includes:

[0058] An association setting unit, configured to execute step S1;

[0059] The dynamic adjustment unit is configured to execute step S2.

[0060] The contents of the above method embodiments are all applicable to the present system embodiments. The functions specifically implemented by the present system embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0061] An adaptive thermal management device for an IGCT-MMC flexible direct current submodule:

[0062] at least one processor;

[0063] at least one memory for storing at least one program;

[0064] When the at least one program is executed by the at least one processor, the at least one processor implements the above-mentioned adaptive thermal management method for the IGCT-MMC flexible direct current submodule.

[0065] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0066] A storage medium stores processor-executable instructions, which are used to implement the above-mentioned adaptive thermal management method for an IGCT-MMC flexible direct current submodule when executed by the processor.

[0067] The contents of the above method embodiments are all applicable to the present storage medium embodiment. The functions specifically implemented by the present storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0068] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An adaptive thermal management method for an IGCT-MMC flexible direct current submodule, characterized in that: The following steps are involved: The power devices of the IGCT-MMC flexible direct current submodule are crimped into a string, and each of the power devices is equipped with a corresponding water-cooled radiator; The flow rate of the water-cooled radiator is dynamically adjusted according to the port current and the inlet water temperature of the IGCT-MMC flexible direct current submodule.

2. The adaptive thermal management method of an IGCT-MMC flexible direct current submodule according to claim 1, characterized in that: The IGCT-MMC flexible direct current submodule includes an upper tube IGCT device, an upper tube freewheeling diode, a lower tube IGCT device, a lower tube freewheeling diode, a DC capacitor, an anode reactance, a clamping diode, a clamping resistor and a clamping capacitor, wherein: The first end of the upper tube IGCT device, the second end of the upper tube freewheeling diode, the first end of the clamping diode and the first end of the anode reactance are connected; The second end of the upper tube IGCT device, the first end of the upper tube freewheeling diode, the first end of the lower tube IGCT device and the second end of the lower tube freewheeling diode are connected; The second end of the lower tube IGCT device, the first end of the lower tube freewheeling diode, the first end of the clamping capacitor and the first end of the DC capacitor are connected; The second end of the DC inductor clamping diode, the first end of the clamping resistor and the second end of the clamping capacitor are connected; The second end of the anode reactance, the second end of the clamping resistor and the second end of the DC capacitor are connected.

3. The adaptive thermal management method of an IGCT-MMC flexible direct current submodule according to claim 2, characterized in that: The formula for the junction temperature of each power device is as follows: R th(S1,S2,D1,D2,DCL) =R th-JC(S1,S2,D1,D2,DCL) +R th-CH(S1,S2,D1,D2,DCL) +R th-sink in, Indicates the junction temperature of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the inverter mode, T in Indicates the submodule inlet water temperature, Indicates the losses of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the inverter mode. It represents the total thermal resistance of the upper tube IGCT device, the lower tube IGCT device, the upper tube freewheeling diode, the lower tube freewheeling diode and the clamping diode. Indicates the junction temperature of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the rectification mode. Indicates the losses of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode in the rectification mode. It represents the junction-to-case thermal resistance of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode. R represents the contact thermal resistance of the upper tube IGCT device, lower tube IGCT device, upper tube freewheeling diode, lower tube freewheeling diode and clamping diode. th-sink Indicates the thermal resistance of the water cooling radiator.

4. The adaptive thermal management method of an IGCT-MMC flexible direct current submodule according to claim 2, characterized in that: The flow resistance of the water-cooled radiator is expressed as follows: P sm =0.6458×x1 1.9992 +0.6458×x2 1.9992 .....+0.6458×x6 1.9992 Among them, x1, x2, x3, x4, x5 and x6 represent the flow rates of the corresponding water cooling radiators.

5. The adaptive thermal management method of an IGCT-MMC flexible direct current submodule according to claim 2, characterized in that: The split ratio of the water-cooled radiator is expressed as follows: Among them, T in Indicates the submodule inlet water temperature, Indicates the loss of the upper tube IGCT device and the clamping diode in the inverter mode, Represents the junction-to-case thermal resistance of the upper IGCT device and the clamping diode. Represents the contact thermal resistance of the upper tube IGCT device and the clamping diode device, Indicates the loss of the lower IGCT device in inverter mode, It represents the junction-to-case thermal resistance of the lower tube IGCT device. represents the contact thermal resistance of the lower tube IGCT device, k represents the shunt ratio, Indicates the loss of the upper tube freewheeling diode and the lower tube freewheeling diode in the inverter mode. Indicates the junction-to-case thermal resistance of the upper and lower freewheeling diodes. Indicates the contact thermal resistance of the upper tube freewheeling diode and the lower tube freewheeling diode. Indicates the loss of the clamping diode in inverter mode.

6. An adaptive thermal management system for an IGCT-MMC flexible submodule, characterized in that: include: The association setting unit presses the power devices of the IGCT-MMC flexible direct current submodule into a string, and each of the power devices is equipped with a corresponding water-cooling radiator; The dynamic adjustment unit is used to dynamically adjust the flow of the water-cooled radiator according to the port current and the inlet water temperature of the IGCT-MMC flexible direct current submodule.

Images