A low-temperature starting method for a hydrogen circulation pump

Abstract

The present invention provides a low-temperature starting method for a hydrogen circulation pump, comprising: judging whether the hydrogen circulation pump meets the low-temperature starting conditions; if the hydrogen circulation pump meets the low-temperature starting conditions, performing low-temperature starting by adopting the self-heating and shaking ice-breaking modes of the hydrogen circulation pump, until the low-temperature starting of the hydrogen circulation pump is successfully completed; wherein, the self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit to be in a high-voltage direct-current working state through the hydrogen circulation pump controller, and utilizing high-voltage direct current to achieve self-heating of the hydrogen circulation pump; that is, the switch module in the high-voltage drive circuit is controlled to be in a high-voltage direct-current working state by the hydrogen circulation pump controller, and high-voltage direct current is supplied to the motor coil of the hydrogen circulation pump, so that the motor coil of the hydrogen circulation pump is rapidly heated, and the generated heat is conducted to the pump head housing, the impeller rotor and the gear box lubricating oil through the motor housing, thereby achieving the rapid self-heating ice melting and lubricating oil heating functions of the hydrogen circulation pump, and the rapid ice-breaking starting of the hydrogen circulation pump without external heating at ultra-low temperatures.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and more particularly relates to a low-temperature starting method for a hydrogen circulation pump. Background Art

[0002] As fuel cell system technology continues to advance, its application areas and scenarios continue to expand, requiring fuel cell systems and components to have stronger environmental adaptability, especially adaptability to ultra-low temperature environments (below -30°C), and require rapid startup and operation. As the primary technical solution for hydrogen circulation in proton exchange membrane fuel cells, hydrogen circulation pumps, starting at low temperatures through ice, have always been a core difficulty in their development.

[0003] The existing low-temperature start-up scheme for hydrogen circulation pumps mainly uses external heating and ice-melting methods, which can basically meet the low-temperature ice-breaking requirements above -30°C. However, the external heating and ice-melting method requires an external power supply for heating before the system is started at low temperature, which is difficult and takes a long time. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a low-temperature starting method for a hydrogen circulation pump, which is used to use a hydrogen circulation pump controller to control the switch module in the high-voltage drive circuit to be in a high-voltage direct working state; to realize the rapid self-heating ice melting and lubricating oil heating functions of the hydrogen circulation pump, and to quickly break the ice and start the hydrogen circulation pump without external heating at ultra-low temperatures.

[0005] The present application provides a low-temperature starting method for a hydrogen circulation pump, comprising:

[0006] Determining whether the hydrogen circulation pump meets the low-temperature startup conditions;

[0007] If the hydrogen circulation pump meets the low-temperature starting conditions, the hydrogen circulation pump self-heating and shaking ice-breaking mode will be used for low-temperature starting until the hydrogen circulation pump is successfully started at low temperature;

[0008] The self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit to be in a high-voltage direct-flow working state through the hydrogen circulation pump controller, and utilizing high-voltage direct current to achieve the self-heating of the hydrogen circulation pump.

[0009] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, the low-temperature starting of the hydrogen circulation pump using the self-heating and shaking ice-breaking mode until the low-temperature starting of the hydrogen circulation pump is successful includes:

[0010] Use hydrogen circulation pump self-heating and shaking ice-breaking mode for low-temperature startup;

[0011] Determine whether the low-temperature start-up of the hydrogen circulation pump is completed;

[0012] If not, the process returns to executing the step of starting the hydrogen circulation pump at low temperature by adopting the self-heating and shaking ice-breaking mode; if so, the hydrogen circulation pump enters the normal operation mode.

[0013] Optionally, in the above-mentioned low-temperature startup method of the hydrogen circulation pump, before returning to executing the low-temperature startup using the self-heating and shaking ice-breaking mode of the hydrogen circulation pump, the method further includes:

[0014] Determining whether the hydrogen circulation pump is in a fault state;

[0015] If the hydrogen circulation pump is in a faulty state, the operation is stopped and the fault is reported;

[0016] If the hydrogen circulation pump is not in a faulty state, the process returns to executing the step of performing low-temperature startup using the self-heating and shaking ice-breaking modes of the hydrogen circulation pump.

[0017] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, the switch module is in a high-voltage direct working state, which includes: UV phase direct, UW phase direct, VU phase direct, VW phase direct, WU phase direct, WU phase direct in the switch module;

[0018] The UV phase direct pass is to close the U phase upper bridge and the V phase lower bridge at the same time, and all other power modules are disconnected;

[0019] The UW phase direct pass is to close the U phase upper bridge and the W phase lower bridge at the same time, and all other power modules are disconnected;

[0020] The VU phase direct pass is to close the V phase upper bridge and the U phase lower bridge at the same time, and all other power modules are disconnected;

[0021] The VW phase direct pass is to close the V phase upper bridge and the W phase lower bridge at the same time, and disconnect all other power modules;

[0022] The WU phase direct connection is to close the W phase upper bridge and the U phase lower bridge at the same time, and all other power modules are disconnected;

[0023] The WV phase direct connection is to close the W phase upper bridge and the V phase lower bridge at the same time, and all other power modules are disconnected.

[0024] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, the determining whether the hydrogen circulation pump meets the low-temperature starting condition includes:

[0025] Determine whether the hydrogen circulation pump meets the start-up requirements and the ambient temperature is lower than a preset temperature.

[0026] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, determining whether the hydrogen circulation pump meets the low-temperature starting conditions includes:

[0027] When the hydrogen circulation pump needs to be started and the ambient temperature is not lower than the preset temperature, the hydrogen circulation pump is started according to the normal starting mode corresponding to the current situation;

[0028] Determine whether the normal startup mode corresponding to the current situation is successfully started;

[0029] If the conventional startup mode corresponding to the current situation cannot be successfully started, it is determined that the hydrogen circulation pump meets the low-temperature startup condition.

[0030] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, starting the hydrogen circulation pump according to a conventional starting mode corresponding to the current situation of the hydrogen circulation pump includes:

[0031] Check whether the hydrogen circulation pump needs to be started at low temperature;

[0032] If so, the hydrogen circulation pump is started in a conventional low-temperature ice-breaking mode;

[0033] If not, the hydrogen circulation pump is started in a normal temperature start mode.

[0034] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, determining whether the conventional starting mode corresponding to the current situation is successfully started includes:

[0035] Determine whether the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode;

[0036] If the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode, the hydrogen circulation pump enters the normal operating mode;

[0037] If the hydrogen circulation pump fails to start in the conventional low-temperature ice-breaking mode, determining whether the hydrogen circulation pump is in a fault state;

[0038] If the hydrogen circulation pump is in a faulty state, the operation is stopped and the fault is reported;

[0039] If the hydrogen circulation pump is not in a faulty state, the conventional startup mode corresponding to the current situation cannot be successfully started, and it is determined that the hydrogen circulation pump meets the low-temperature startup condition.

[0040] Optionally, in the above-mentioned low-temperature startup method of the hydrogen circulation pump, before or after any step, the method further includes:

[0041] Determine the optimal zero angle of the impeller rotor in the hydrogen circulation pump, and determine the motor parameters and stator winding method of the hydrogen circulation pump based on the optimal zero angle. After each shutdown, apply a single-phase voltage Ud to the U-axis / q-axis of the hydrogen circulation pump motor so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

[0042] Optionally, in the above-mentioned low-temperature starting method of the hydrogen circulation pump, determining the optimal zero angle of the impeller rotor in the hydrogen circulation pump, and determining the motor parameters and stator winding method of the hydrogen circulation pump based on the optimal zero angle, and applying a single-phase voltage Ud to the U axis / q axis of the hydrogen circulation pump motor after each shutdown, so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down, including:

[0043] According to the structural characteristics of the impeller rotors of the hydrogen circulation pump, the optimal zero position angle of the impeller rotors is designed and determined in a preset state where water is least likely to accumulate between the impeller rotors;

[0044] Based on the optimal zero angle, the motor parameters and stator winding method are determined to ensure that the angle θ between the d-axis of the rotor coordinate system of the motor and the α-axis of the stator coordinate system is equal to the optimal zero angle, and an origin coordinate system is established with the impeller rotor axis as the center and the horizontal direction as the U axis, and the d-axis of the rotor coordinate system coincides with the U axis;

[0045] After the hydrogen circulation pump is shut down, a single-phase voltage Ud is applied to the U-axis / q-axis of the hydrogen circulation pump motor, and the electromagnetic force attracts the motor rotor to a preset position, so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

[0046] It can be seen from the above technical solution that the present invention provides a low-temperature starting method for a hydrogen circulation pump, including: judging whether the hydrogen circulation pump meets the low-temperature starting conditions; if the hydrogen circulation pump meets the low-temperature starting conditions, the hydrogen circulation pump self-heating and shaking ice-breaking mode are used for low-temperature starting until the hydrogen circulation pump is successfully started at low temperature; wherein, the self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit through the hydrogen circulation pump controller to be in a high-voltage direct-through working state, and utilizing high-voltage direct current to achieve self-heating of the hydrogen circulation pump; that is, the hydrogen circulation pump controller is used to control the switch module in the high-voltage drive circuit to be in a high-voltage direct-through working state, and high-voltage direct current is passed into the hydrogen circulation pump motor coil, so that the hydrogen circulation pump motor coil quickly heats up, and the generated heat is conducted to the pump head housing, impeller rotor and gearbox lubricating oil through the motor housing, thereby realizing the rapid self-heating ice melting and lubricating oil heating functions of the hydrogen circulation pump, and the hydrogen circulation pump quickly starts without external heating and breaking ice at ultra-low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1This is a flow chart of a low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0049] Figure 2 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0050] Figure 3 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0051] Figure 4 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0052] Figure 5 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0053] Figure 6 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0054] Figure 7 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0055] Figure 8 This is a flow chart of another low-temperature startup method for a hydrogen circulation pump provided by an embodiment of the present invention;

[0056] Figure 9 This is a schematic diagram of the high-voltage control circuit of the hydrogen circulation pump controller provided by an embodiment of the present invention;

[0057] Figure 10-15 This is a schematic diagram of the switch timing of the high-voltage control circuit of the hydrogen circulation pump controller provided by an embodiment of the present invention;

[0058] Figure 16 2. It is a schematic diagram of the zero-position angle of the impeller rotor of the hydrogen circulation pump provided by an embodiment of the present invention;

[0059] Figure 17 It is a schematic diagram of a reference coordinate system for the design of a hydrogen circulation pump motor provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0061] In this application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0062] The embodiment of the present application provides a low-temperature starting method for a hydrogen circulation pump, which is used to solve the problem that the external heating and ice-melting method in the prior art requires an external power supply for heating before the system is started at low temperature, which is difficult and takes a long time to heat.

[0063] See also Figure 1 The low-temperature starting method of the hydrogen circulation pump comprises:

[0064] S101. Determine whether the hydrogen circulation pump meets the low-temperature starting conditions.

[0065] It should be noted that the low-temperature startup condition can have various situations, such as detecting that the temperature is lower than a preset temperature, and failing to start the vehicle using the conventional startup mode. The preset temperature can be -30°C, but of course the preset temperature is not limited to -30°C. This will not be detailed here one by one. It can be determined according to the actual situation and is within the scope of protection of this application.

[0066] The specific content of the low-temperature starting conditions will not be described here in detail. It will depend on the actual situation and is within the scope of protection of this application.

[0067] It should be noted that if the hydrogen circulation pump meets the low-temperature starting conditions, it means that the hydrogen circulation pump needs to be started using the starting method provided in this application, so step S102 is executed; however, if the hydrogen circulation pump does not meet the low-temperature starting conditions, the hydrogen circulation pump can be started in a variety of ways, such as conventional starting methods, conventional low-temperature starting methods, etc. Of course, the self-heating and shaking ice-breaking starting methods of the hydrogen circulation pump provided in this application are not excluded. They will not be described one by one here, and it can be determined according to the actual situation. They are all within the scope of protection of this application.

[0068] That is, if the hydrogen circulation pump meets the low-temperature start-up condition, step S102 is executed.

[0069] S102. Use the self-heating and shaking ice-breaking mode of the hydrogen circulation pump to start at low temperature until the hydrogen circulation pump starts at low temperature successfully.

[0070] Among them, the self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit through the hydrogen circulation pump controller to be in a high-voltage direct-through working state, and utilizing high-voltage direct current to achieve self-heating of the hydrogen circulation pump.

[0071] Specifically, the hydrogen circulation pump may enter the shaking ice-breaking mode and start the hydrogen circulation pump after self-heating for a period of time.

[0072] That is to say, the hydrogen circulation pump is heated and started by self-heating. The specific heating method is to control the switch module to be in a high-voltage direct-through state, so that there is high-voltage direct current in the hydrogen circulation pump, thereby realizing self-heating of the hydrogen circulation pump.

[0073] The hydrogen circulation pump controller controls the switch module in the high-voltage drive circuit to be in a high-voltage direct-through working state by controlling the upper and lower bridges in the switch module to be conductive, wherein the conductive upper and lower bridges are in different phases. The switch module includes a V phase, a U phase, and a W phase.

[0074] Of course, other methods can also be used to achieve the high-voltage direct working state, which will not be described here one by one. It depends on the actual situation and is within the scope of protection of this application.

[0075] The self-heating of the hydrogen circulation pump is achieved through the high-voltage direct current of the hydrogen circulation pump controller, which uses high-voltage direct current to quickly heat the hydrogen circulation pump motor coil and quickly transfer the heat to the impeller rotor and gearbox in the pump head, thereby achieving rapid ice melting of the pump head and heating of the gearbox lubricating oil.

[0076] It should be noted that the self-heating of the hydrogen circulation pump can allow high-voltage direct current to be passed into the motor coil of the hydrogen circulation pump, causing the motor coil of the hydrogen circulation pump to self-heat quickly, and the generated heat is transferred to the pump head housing, impeller rotor and gearbox lubricating oil through the motor casing, thereby realizing the rapid self-heating ice melting and lubricating oil heating functions of the hydrogen circulation pump, preventing the lubricating oil of the hydrogen circulation pump from freezing and losing its flow characteristics at ultra-low temperatures, and combining with the high-frequency / low-frequency jitter ice-breaking strategy to achieve rapid ice-breaking start-up of the hydrogen circulation pump without external heating at ultra-low temperatures (such as -30°C).

[0077] In this embodiment, it is determined whether the hydrogen circulation pump meets the low-temperature starting conditions; if the hydrogen circulation pump meets the low-temperature starting conditions, the hydrogen circulation pump self-heating and shaking ice-breaking mode are used for low-temperature starting until the hydrogen circulation pump is successfully started at low temperature; wherein, the self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit through the hydrogen circulation pump controller to be in a high-voltage direct-through working state, and utilizing high-voltage direct current to achieve self-heating of the hydrogen circulation pump; that is, the hydrogen circulation pump controller is used to control the switch module in the high-voltage drive circuit to be in a high-voltage direct-through working state, and high-voltage direct current is passed through the hydrogen circulation pump motor coil, so that the hydrogen circulation pump motor coil quickly heats up, and the generated heat is conducted to the pump head housing, impeller rotor and gearbox lubricating oil through the motor housing, thereby realizing the hydrogen circulation pump's rapid self-heating ice melting and lubricating oil heating functions, and the hydrogen circulation pump quickly starts without external heating and breaking ice at ultra-low temperatures.

[0078] It should be noted that the existing technology also includes limited torque for breaking ice by simple shaking, and low-temperature starting cannot be completed under conditions of lower temperatures or more severe icing.

[0079] The present application combines shaking ice breaking with self-heating of the hydrogen circulation pump to achieve rapid ice breaking and startup of the hydrogen circulation pump without external heating at ultra-low temperatures.

[0080] In practical applications, see Figure 2 Step S102: Using the self-heating and shaking ice-breaking mode of the hydrogen circulation pump to start at low temperature until the hydrogen circulation pump starts at low temperature successfully, including:

[0081] S201, use the hydrogen circulation pump self-heating and shaking ice-breaking mode to start at low temperature.

[0082] It should be noted that the hydrogen circulation pump self-heating and shaking ice-breaking modes can be divided into the hydrogen circulation pump self-heating mode and the hydrogen circulation pump shaking ice-breaking mode. The hydrogen circulation pump self-heating mode is a heating mode that heats the hydrogen circulation pump to increase its temperature and also melts ice at high temperature. The hydrogen circulation pump shaking ice-breaking mode is a shaking mode that breaks and removes frozen ice through shaking.

[0083] Of course, other methods are also possible, which will not be detailed here one by one. It depends on the actual situation and is within the scope of protection of this application.

[0084] S202: Determine whether the low-temperature start-up of the hydrogen circulation pump is completed.

[0085] If not, the process returns to step S201 and uses the hydrogen circulation pump self-heating and shaking ice-breaking mode to start at low temperature. If yes, the process proceeds to step S203.

[0086] S203. The hydrogen circulation pump enters normal operation mode.

[0087] That is to say, after the hydrogen circulation pump is fully started at low temperature, it can operate normally and perform corresponding actions, such as recycling the unreacted hydrogen at the outlet of the fuel cell stack to the inlet of the fuel cell stack, thereby improving the utilization rate of hydrogen and the safety of hydrogen use.

[0088] The specific actions in the normal operating mode will not be described here one by one. They will be determined according to the actual situation and are all within the scope of protection of this application.

[0089] In practical applications, see Figure 3 Before returning to step 201 and using the hydrogen circulation pump self-heating and shaking ice-breaking mode to start at low temperature, the method further includes:

[0090] S301. Determine whether the hydrogen circulation pump is in a faulty state.

[0091] There are many ways to determine whether the hydrogen circulation pump is in a fault state. Self-detection can be used to determine whether it is in a fault state. Of course, other methods can also be used. I will not go into details here. It depends on the actual situation and is within the scope of protection of this application.

[0092] If the hydrogen circulation pump is in a faulty state, execute step S302.

[0093] S302: Stop running and report the fault.

[0094] That is to say, if the hydrogen circulation pump is in a faulty state, it cannot operate normally, so it can stop running, report the fault, and perform inspection and maintenance through automatic inspection and maintenance or manual inspection and maintenance. The specific inspection and maintenance methods will not be described here one by one, and will depend on the actual situation. They are all within the scope of protection of this application.

[0095] If the hydrogen circulation pump is not in a faulty state, the process returns to step S201 and uses the self-heating and shaking ice-breaking modes of the hydrogen circulation pump to perform low-temperature startup.

[0096] That is to say, the hydrogen circulation pump self-heating and shaking ice-breaking mode are continuously executed for low-temperature startup until the low-temperature startup is completed.

[0097] It should be noted that the high-voltage direct pass of the hydrogen circulation pump controller is achieved by driving the electronic control to control the switching timing of switching power devices such as IGBT / MOS tubes.

[0098] Specifically, the switch module being in the high-voltage direct working state includes: UV phase direct, UW phase direct, VU phase direct, VW phase direct, WU phase direct, and WU phase direct in the switch module.

[0099] Specifically, the controller high-voltage pass-through refers to controlling the upper and lower bridges of the U, V, and W single-phases of the IGBT module in the high-voltage drive circuit to be turned on at the same time to form a high-voltage DC closed-loop circuit. The specific switching timing control is UV phase pass-through, UW phase pass-through, VU phase pass-through, VW phase pass-through, WU phase pass-through, and WU phase pass-through.

[0100] like Figure 9 Figure 1 shows the schematic diagram of the high-voltage control circuit of the hydrogen circulation pump controller. HVDC_P and HVDC_N are the positive and negative electrodes; X and Y are capacitors. The IGBT package module is the switch module. The control drive is the control signal; U, V, and W are different phases.

[0101] Among them, UV phase direct pass is to close the U phase upper bridge and V phase lower bridge at the same time, and all other power modules are disconnected (such as Figure 10 shown).

[0102] UW phase direct connection means closing the U phase upper bridge and W phase lower bridge at the same time, and disconnecting all other power modules (such as Figure 11 shown).

[0103] VU phase direct pass is to close the V phase upper bridge and U phase lower bridge at the same time, and all other power modules are disconnected (such as Figure 12 shown).

[0104] VW phase direct pass means closing the upper bridge of V phase and the lower bridge of W phase at the same time, and disconnecting all other power modules (such as Figure 13 shown).

[0105] WU phase direct connection is to close the W phase upper bridge and U phase lower bridge at the same time, and all other power modules are disconnected (such as Figure 14 shown).

[0106] WV phase direct connection is to close the W phase upper bridge and V phase lower bridge at the same time, and all other power modules are disconnected (such as Figure 15 shown).

[0107] It should be noted that the switch module may be an IGBT module, and the switch module includes a switch power device.

[0108] There are 6 combination modes for high-voltage pass-through and switch timing control of switching power devices. UV phase pass-through (1-1) is to close the U upper bridge and V lower bridge at the same time, and the other power modules are all disconnected. UW phase pass-through (1-2) is to close the U upper bridge and W lower bridge at the same time, and the other power modules are all disconnected. VU phase pass-through (1-3) is to close the V upper bridge and U lower bridge at the same time, and the other power modules are all disconnected. VW phase pass-through (1-4) is to close the V upper bridge and W lower bridge at the same time, and the other power modules are all disconnected. WU phase pass-through (1-5) is to close the W upper bridge and U lower bridge at the same time, and the other power modules are all disconnected. WV phase pass-through (1-6) is to close the W upper bridge and V lower bridge at the same time, and the other power modules are all disconnected.

[0109] Among them, the above six combination modes are executed in turn.

[0110] It should be noted that since the power devices such as IGBT / MOS tubes and motor coils of the hydrogen circulation pump and controller heat up rapidly in a high-voltage direct-through environment, in order to avoid overheating and burning of the power devices and motor coils, it is necessary to accurately control the duration of each direct-through mode based on the temperature signal feedback of the power devices and motor stators, and turn them on alternately.

[0111] The present application solution is applicable to low-temperature startup of various forms of hydrogen circulation pumps.

[0112] In this embodiment, a high-voltage direct-through hydrogen circulation pump controller is adopted, and the switching timing of power devices such as IGBT / MOS tubes is controlled by a driving circuit, and high-voltage direct current is directly supplied to the hydrogen circulation pump motor coil, so that the hydrogen circulation pump motor coil heats up quickly, and the generated heat is transferred to the pump head, impeller rotor and gearbox lubricating oil through the motor casing, so as to realize the rapid self-heating ice melting and lubricating oil heating function of the hydrogen circulation pump, and prevent the hydrogen circulation pump lubricating oil from freezing and losing its flow characteristics at ultra-low temperatures. Then, combined with a high-frequency or low-frequency jitter ice-breaking strategy, the self-starting function of the hydrogen circulation pump at ultra-low temperatures (below -30°C) is realized. In this process, the control logic of the switching timing needs to be based on the safety protection temperature of the power devices and motor coils to prevent the power devices or motor coils from burning.

[0113] In practical applications, see Figure 4 Step S101, determining whether the hydrogen circulation pump meets the low-temperature start-up conditions, includes:

[0114] S401: Determine whether the hydrogen circulation pump meets the requirements for startup and the ambient temperature is lower than the preset temperature.

[0115] The preset temperature may be -30°C, and whether startup is required may be whether a startup instruction is received.

[0116] The specific judgment process will not be described in detail here. It will depend on the actual situation and is within the scope of protection of this application.

[0117] That is to say, as long as startup is required and the ambient temperature is below -30°C, the hydrogen circulation pump self-heating and shaking ice-breaking mode will be used for low-temperature startup until the hydrogen circulation pump is successfully started at low temperature.

[0118] Specifically, when the ambient temperature is detected to be lower than -30°C, the hydrogen circulation pump self-heating and shaking ice-breaking mode proposed in this application is directly entered until the hydrogen circulation pump is successfully started at low temperature.

[0119] It should be noted that before determining whether the hydrogen circulation pump meets the low-temperature start-up conditions, the ambient temperature can also be detected in real time. The specific detection process will not be described here one by one. It depends on the actual situation and is within the scope of protection of this application.

[0120] In practical applications, see Figure 5 Step S101, determining whether the hydrogen circulation pump meets the low-temperature start-up conditions, includes:

[0121] S501. When the hydrogen circulation pump needs to be started and the ambient temperature is not lower than a preset temperature, the hydrogen circulation pump is started according to a normal starting mode corresponding to the current situation.

[0122] The preset temperature may be -30°C, and whether startup is required may be whether a startup instruction is received.

[0123] That is, when the temperature is detected to be higher than the preset temperature, the normal startup mode can be used for startup.

[0124] The conventional startup mode may include a conventional low-temperature ice-breaking mode and a normal temperature startup mode. Of course, other contents may also be included, which will not be described here one by one. It depends on the actual situation and is within the scope of protection of this application.

[0125] Specifically, starting the hydrogen circulation pump according to a conventional starting mode corresponding to the current situation may be starting the hydrogen circulation pump according to a mode corresponding to the current temperature situation.

[0126] If the temperature is normal, the normal temperature start mode is used; if the temperature is low, the low temperature start mode is used.

[0127] The low temperature is different from the above-mentioned preset temperature, and the low temperature is higher than the above-mentioned preset temperature.

[0128] The specific circumstances of determining low temperature and normal temperature will not be described here one by one. It will depend on the actual situation and is within the scope of protection of this application.

[0129] S502: Determine whether the normal startup mode corresponding to the current situation is successfully started.

[0130] If the conventional startup mode corresponding to the current situation cannot be successfully started, it is determined that the hydrogen circulation pump meets the low-temperature startup conditions and step S102 is executed.

[0131] That is to say, whether it can start successfully under the current startup mode, if it cannot start successfully, it is necessary to use the hydrogen circulation pump self-heating and shaking ice-breaking mode to start at low temperature until the hydrogen circulation pump starts successfully at low temperature.

[0132] In practical applications, see Figure 6 The step S501 involves starting the hydrogen circulation pump in a conventional starting mode corresponding to the current situation, including:

[0133] S601. Check whether the hydrogen circulation pump needs to be started at low temperature.

[0134] Specifically, it can be determined by detecting whether the temperature of the hydrogen circulation pump is higher than a first temperature. If it is higher than the first temperature, the hydrogen circulation pump does not need to be started at a low temperature. If it is lower than the first temperature, the hydrogen circulation pump needs to be started at a low temperature.

[0135] The first temperature is higher than the preset temperature, that is, the first temperature is higher than -30° C. The specific value of the first temperature will not be detailed here, and can be determined according to actual conditions, and all are within the scope of protection of this application.

[0136] If the hydrogen circulation pump needs to be started at a low temperature, step S602 is executed.

[0137] S602, the hydrogen circulation pump is started using the conventional low-temperature ice-breaking mode.

[0138] It should be noted that the conventional low-temperature ice-breaking mode can be an existing low-temperature starting mode. The specific starting process will not be described here in detail. It will depend on the actual situation and is within the scope of protection of this application.

[0139] If not, execute step S603.

[0140] S603, the hydrogen circulation pump is started in normal temperature start mode.

[0141] The normal temperature startup mode is the existing normal temperature startup mode. The specific startup process will not be described here in detail. It depends on the actual situation and is within the protection scope of this application.

[0142] It should be noted that if the hydrogen circulation pump is started in a normal temperature start-up mode, step S502 may not be performed.

[0143] In practical applications, see Figure 7 Step S502: determining whether the normal startup mode corresponding to the current situation is successfully started, including:

[0144] S701. Determine whether the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode.

[0145] If the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode, step S702 is executed.

[0146] S702. The hydrogen circulation pump enters normal operation mode.

[0147] If the hydrogen circulation pump fails to start in the conventional low-temperature ice-breaking mode, step S703 is executed.

[0148] S703: Determine whether the hydrogen circulation pump is in a faulty state.

[0149] If the hydrogen circulation pump is in a faulty state, step S704 is executed to stop the operation and report the fault.

[0150] If the hydrogen circulation pump is not in a faulty state, the conventional startup mode corresponding to the current situation cannot be successfully started, and it is determined that the hydrogen circulation pump meets the low-temperature startup condition, and step S102 is executed.

[0151] That is to say, detect whether the hydrogen circulation pump has entered the low-temperature start-up mode, first try to use the conventional low-temperature ice-breaking mode to start the hydrogen circulation pump, and detect whether the hydrogen circulation pump is in a fault state. If the start-up is successful, enter the normal operation mode. If the start-up fails and is in a fault state, stop running and report the fault; if the start-up fails but is not in a fault state, enter the hydrogen circulation pump self-heating and shaking ice-breaking mode proposed in the application.

[0152] In this embodiment, high-voltage direct current is used to achieve rapid self-heating of the hydrogen circulation pump, thereby realizing the functions of rapid ice melting and lubricating oil heating, solving the technical problem of difficulty in starting the hydrogen circulation pump or long starting time without external heating in ultra-low temperature environments; at the same time, it solves the technical problem of lubricating oil failure caused by viscosity or freezing of lubricating oil in ultra-low temperature environments or requiring greater torque to overcome the viscous resistance of the lubricating oil.

[0153] It should be noted that if Figure 8 As shown, a specific implementation step of the low-temperature starting method of the hydrogen circulation pump using a high-voltage direct current of the hydrogen circulation pump controller to achieve rapid self-heating of the hydrogen circulation pump, thereby achieving rapid ice melting and lubricating oil heating functions is described:

[0154] ①. Check whether the hydrogen circulation pump has entered the low temperature mode.

[0155] ②. If the hydrogen circulation pump has entered the low-temperature mode, first try to start the hydrogen circulation pump using the conventional low-temperature ice-breaking mode, and check whether the hydrogen circulation pump is in a fault state; if the hydrogen circulation pump has not entered the low-temperature mode, start the hydrogen circulation pump using the normal temperature start-up mode.

[0156] ③. When it is detected that the hydrogen circulation pump is in a non-fault state and the conventional low-temperature ice-breaking mode is invalid, or when the ambient temperature is detected to be lower than -30°C, the high-pressure direct mode of the hydrogen circulation pump controller is turned on; if the hydrogen circulation pump is in a fault state, the hydrogen circulation pump is stopped and the fault is reported.

[0157] ④. The high-voltage direct-through mode of the hydrogen circulation pump controller is achieved by driving the electronic control to control the switching timing of power devices such as IGBT / MOS tubes.

[0158] ⑤. There are 6 combination modes for high-voltage pass-through and switch timing control of power devices. UV phase pass-through (1-1) is to close the U upper bridge and V lower bridge at the same time, and the other power modules are all disconnected. UW phase pass-through (1-2) is to close the U upper bridge and W lower bridge at the same time, and the other power modules are all disconnected. VU phase pass-through (1-3) is to close the V upper bridge and U lower bridge at the same time, and the other power modules are all disconnected. VW phase pass-through (1-4) is to close the V upper bridge and W lower bridge at the same time, and the other power modules are all disconnected. WU phase pass-through (1-5) is to close the W upper bridge and U lower bridge at the same time, and the other power modules are all disconnected. WV phase pass-through (1-6) is to close the W upper bridge and V lower bridge at the same time, and the other power modules are all disconnected.

[0159] ⑥. Since the power devices such as IGBT / MOS tubes and motor coils of the hydrogen circulation pump and controller heat up rapidly in a high-voltage direct-through environment, in order to avoid overheating and burning of the power devices and motor coils, it is necessary to accurately control the duration of each direct-through mode based on the temperature signal feedback of the power devices and motor stators, and turn them on alternately.

[0160] ⑦. After the hydrogen circulation pump self-heats for a period of time, it enters the shaking ice-breaking mode to start the hydrogen circulation pump.

[0161] ⑧. Repeat ③ to ⑦ until the hydrogen circulation pump starts successfully.

[0162] In practical applications, before and after any step, it also includes:

[0163] Determine the optimal zero angle of the impeller rotor in the hydrogen circulation pump, and determine the motor parameters and stator winding method of the hydrogen circulation pump based on the optimal zero angle. After each shutdown, apply single-phase voltage Ud to the U axis / q axis of the hydrogen circulation pump motor so that the impeller rotor can be reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

[0164] That is to say, if Figure 16 As shown in the figure, the optimal zero position angle θ of the impeller rotor is designed, and the relevant parameters of the motor and the stator winding method are designed based on the optimal zero position angle θ of the impeller rotor. A single-phase voltage Ud is immediately applied to the U axis / q axis of the hydrogen circulation pump motor after each shutdown, so that the impeller rotor can be reset to the optimal zero position angle each time the hydrogen circulation pump is shut down, thereby preventing water accumulation and freezing between the impeller rotor.

[0165] Among them, such as Figure 16 As shown, ω is the impeller speed; inlet is the air inlet of the hydrogen circulation pump; outlet is the air outlet of the hydrogen circulation pump, and θ is the optimal zero position angle.

[0166] In this embodiment, in order to avoid water accumulation and freezing between the impeller rotors at low temperatures, the present application proposes an optimal zero angle of the impeller rotor, and designs relevant parameters of the motor and the stator winding method based on the optimal zero angle of the impeller rotor. Immediately after each shutdown, a single-phase voltage Ud is applied to the stator coil of the hydrogen circulation pump. A specific electromagnetic force will attract the motor rotor to a specific position, so that the impeller rotor can be reset to the optimal zero angle each time the hydrogen circulation pump is shut down, preventing water accumulation and freezing between the impeller rotor, and promoting the hydrogen circulation pump to quickly break the ice and start at ultra-low temperatures (-30°C).

[0167] In practical applications, the optimal zero angle of the impeller rotor in the hydrogen circulation pump is determined, and the motor parameters and stator winding method of the hydrogen circulation pump are determined based on the optimal zero angle. After each shutdown, a single-phase voltage Ud is applied to the U axis / q axis of the hydrogen circulation pump motor so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down, including:

[0168] (1) According to the structural characteristics of the impeller rotor of the hydrogen circulation pump, the optimal zero position angle of the impeller rotor is designed and determined under the preset state where water is least likely to accumulate between each impeller rotor.

[0169] Specifically, ① based on the structural characteristics of the hydrogen circulation pump impeller rotor, it is determined that the impeller rotor (2-1) and (2-2) are in a state where water is least likely to accumulate, and the optimal zero position angle θ of the impeller rotor is designed and determined.

[0170] For example, for a two-blade straight-lobe Roots-type hydrogen circulation pump, when the angle θ between the long side of the impeller rotor and the horizontal radial direction is 45°, water is least likely to accumulate between the impeller rotors. Therefore, θ=45° is designed as the optimal zero position angle of the impeller rotor of the two-blade straight-lobe Roots-type hydrogen circulation pump.

[0171] 2-1 and 2-2 are both impeller rotors. 2 blades means that there are 2 blades on an impeller, and straight blades means that the cross-sections in terms of thickness are shown in 2-1 and 2-2.

[0172] (2) Based on the optimal zero-position angle, the motor parameters and stator winding method are determined to ensure that the angle θ between the d-axis of the motor's rotor coordinate system and the α-axis of the stator coordinate system is equal to the optimal zero-position angle, and the origin coordinate system is established with the impeller rotor axis as the center and the horizontal direction as the U axis, while the d-axis of the rotor coordinate system coincides with the U axis.

[0173] Specifically, such as Figure 17As shown, after determining the optimal zero angle of the impeller rotor, it is necessary to design the motor parameters and stator winding method in detail based on the optimal zero angle of the impeller rotor to ensure that the angle θ between the rotor coordinate system d axis (3-1) and the stator coordinate system α axis (3-2) is equal to the optimal zero angle of the impeller rotor. In the motor design, the origin coordinate system needs to be established with the impeller rotor axis as the center and the U axis in the horizontal direction, and the d axis of the rotor coordinate system coincides with the U axis.

[0174] (3) After the hydrogen circulation pump is shut down, a single-phase voltage Ud is applied to the U-axis / q-axis of the hydrogen circulation pump motor. The electromagnetic force attracts the motor rotor to a preset position so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

[0175] Specifically, based on the special motor design, a single-phase voltage Ud is applied to the U-axis / q-axis of the hydrogen circulation pump motor immediately after each shutdown. The specific electromagnetic force will attract the motor rotor to a specific position, so that the impeller rotor can be reset to the optimal zero angle every time the hydrogen circulation pump is shut down.

[0176] It should be noted that this scheme uses a two-blade straight-blade Roots-type hydrogen circulation pump as an example to design the optimal zero-position angle and zero-position reset method of the impeller rotor. Impeller rotors of other structures can also adopt the core zero-position reset idea of this method.

[0177] In this embodiment, the impeller rotor zero-position reset scheme minimizes the accumulation of water and ice between the impeller rotors, solving the technical problem of the hydrogen circulation pump impeller rotor being stuck due to ice and unable to break the ice and start; at the same time, this method does not require the use of a position sensor, and the impeller rotor zero-position reset function can be achieved through preliminary design and software logic, thereby improving the reliability of the hydrogen circulation pump and reducing the cost of the hydrogen circulation pump.

[0178] It should be noted that the optimal zero angle θ of the impeller rotor is designed in the low-temperature starting method of the hydrogen circulation pump, and the relevant parameters of the motor and the stator winding method are designed based on the optimal zero angle θ of the impeller rotor. Immediately after each shutdown, a single-phase voltage Ud is applied to the U-axis / q-axis of the hydrogen circulation pump motor to ensure that the impeller rotor can be reset to the optimal zero angle each time the hydrogen circulation pump is shut down, preventing water accumulation and freezing between the impeller rotor, thereby achieving rapid ice-breaking start-up of the hydrogen circulation pump under low temperature conditions.

[0179] The features described in the various embodiments of this specification can be replaced or combined with each other. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple. For relevant parts, refer to the partial description of the method embodiment. The system and system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without expending creative work.

[0180] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0181] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for starting a hydrogen circulation pump at low temperature, characterized in that: include: Determining whether the hydrogen circulation pump meets the low-temperature startup conditions; If the hydrogen circulation pump meets the low-temperature starting conditions, the hydrogen circulation pump self-heating and shaking ice-breaking mode will be used for low-temperature starting until the hydrogen circulation pump is successfully started at low temperature; Wherein, the self-heating of the hydrogen circulation pump is achieved by controlling the switch module in the high-voltage drive circuit to be in a high-voltage direct working state through the hydrogen circulation pump controller, and utilizing high-voltage direct current to achieve the self-heating of the hydrogen circulation pump; The method of using the self-heating and shaking ice-breaking mode of the hydrogen circulation pump to start at low temperature until the hydrogen circulation pump starts at low temperature successfully includes: Use hydrogen circulation pump self-heating and shaking ice-breaking mode for low-temperature startup; Determine whether the low-temperature start-up of the hydrogen circulation pump is completed; If so, the hydrogen circulation pump enters normal operating mode; If not, determining whether the hydrogen circulation pump is in a fault state; If the hydrogen circulation pump is in a faulty state, stop running and report the fault; If the hydrogen circulation pump is not in a faulty state, the method returns to the step of performing low-temperature startup using the self-heating and dithering ice-breaking mode of the hydrogen circulation pump; wherein the switch module is in a high-voltage direct-through working state, which includes: UV phase direct-through, UW phase direct-through, VU phase direct-through, VW phase direct-through, WU phase direct-through, and WV phase direct-through in the switch module; The UV phase direct pass is to close the U phase upper bridge and the V phase lower bridge at the same time, and all other power modules are disconnected; The UW phase direct pass is to close the U phase upper bridge and the W phase lower bridge at the same time, and all other power modules are disconnected; The VU phase direct pass is to close the V phase upper bridge and the U phase lower bridge at the same time, and all other power modules are disconnected; The VW phase direct pass is to close the V phase upper bridge and the W phase lower bridge at the same time, and disconnect all other power modules; The WU phase direct connection is to close the W phase upper bridge and the U phase lower bridge at the same time, and all other power modules are disconnected; The WV phase direct connection is to close the W phase upper bridge and the V phase lower bridge at the same time, and all other power modules are disconnected.

2. The low-temperature startup method for a hydrogen circulation pump according to claim 1, characterized in that: The determining whether the hydrogen circulation pump meets the low-temperature startup condition includes: Determine whether the hydrogen circulation pump meets the start-up requirements and the ambient temperature is lower than a preset temperature.

3. The low-temperature startup method for a hydrogen circulation pump according to claim 1, characterized in that: Determining whether the hydrogen circulation pump meets the low-temperature startup conditions includes: When the hydrogen circulation pump needs to be started and the ambient temperature is not lower than the preset temperature, the hydrogen circulation pump is started according to the normal starting mode corresponding to the current situation; Determine whether the normal startup mode corresponding to the current situation is successfully started; If the conventional startup mode corresponding to the current situation cannot be successfully started, it is determined that the hydrogen circulation pump meets the low-temperature startup condition.

4. The low-temperature startup method for a hydrogen circulation pump according to claim 3, characterized in that: Starting the hydrogen circulation pump according to the conventional starting mode corresponding to the current situation includes: Check whether the hydrogen circulation pump needs to be started at low temperature; If so, the hydrogen circulation pump is started in a conventional low-temperature ice-breaking mode; If not, the hydrogen circulation pump is started in a normal temperature start mode.

5. The low-temperature startup method for a hydrogen circulation pump according to claim 4, characterized in that: Determining whether the normal startup mode corresponding to the current situation is successfully started includes: Determine whether the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode; If the hydrogen circulation pump is successfully started in the conventional low-temperature ice-breaking mode, the hydrogen circulation pump enters the normal operating mode; If the hydrogen circulation pump fails to start in the conventional low-temperature ice-breaking mode, determining whether the hydrogen circulation pump is in a fault state; If the hydrogen circulation pump is in a faulty state, stop running and report the fault; If the hydrogen circulation pump is not in a faulty state, the conventional startup mode corresponding to the current situation cannot be successfully started, and it is determined that the hydrogen circulation pump meets the low-temperature startup condition.

6. The low-temperature startup method for a hydrogen circulation pump according to any one of claims 1 to 5, characterized in that: Before and after any step, also include: Determine the optimal zero angle of the impeller rotor in the hydrogen circulation pump, and determine the motor parameters and stator winding method of the hydrogen circulation pump based on the optimal zero angle. After each shutdown, apply a single-phase voltage Ud to the U-axis / q-axis of the hydrogen circulation pump motor so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

7. The low-temperature startup method for a hydrogen circulation pump according to claim 6, characterized in that: The method of determining an optimal zero angle of an impeller rotor in a hydrogen circulation pump, determining motor parameters and a stator winding method of the hydrogen circulation pump based on the optimal zero angle, and applying a single-phase voltage Ud to the U-axis / q-axis of the hydrogen circulation pump motor after each shutdown so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down, includes: According to the structural characteristics of the impeller rotors of the hydrogen circulation pump, the optimal zero position angle of the impeller rotors is designed and determined in a preset state where water is least likely to accumulate between the impeller rotors; Based on the optimal zero angle, the motor parameters and stator winding method are determined to ensure that the angle θ between the d-axis of the rotor coordinate system of the motor and the α-axis of the stator coordinate system is equal to the optimal zero angle, and an origin coordinate system is established with the impeller rotor axis as the center and the horizontal direction as the U axis, and the d-axis of the rotor coordinate system coincides with the U axis; After the hydrogen circulation pump is shut down, a single-phase voltage Ud is applied to the U-axis / q-axis of the hydrogen circulation pump motor, and the electromagnetic force attracts the motor rotor to a preset position, so that the impeller rotor is reset to the optimal zero angle each time the hydrogen circulation pump is shut down.

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