High-power composite fuel cell system test platform for locomotive and control method

Abstract

The invention relates to the technical field of fuel cell system testing, in particular to a high-power composite fuel cell system testing platform for a locomotive and a control method. The test platform comprises a hydrogen supply module, a main cooling loop and an auxiliary cooling loop, the hydrogen supply module, the main cooling loop and the auxiliary cooling loop are connected to a fuel cell system through pipelines, the hydrogen supply module comprises a hydrogen loop, a nitrogen loop, a flow meter, a medium-pressure pressure sensor and a busbar, and the hydrogen loop and the nitrogen loop are both connected to a main pipeline. A flow meter, a medium-pressure pressure sensor and a plurality of busbars are sequentially installed on the main pipeline. According to the invention, the requirement of simultaneous testing of multiple sets of high-power fuel cell systems can be met, and stable hydrogen flow, pressure and temperature control can be realized.

Description

Technical Field

[0002] This invention relates to the field of fuel cell system testing technology, and in particular to a testing platform and control method for high-power hybrid fuel cell systems used in locomotives. Background Technology

[0004] Proton exchange membrane fuel cells (PEMFCs), as a sustainable energy technology, are developing towards higher power, higher reliability, and intelligent control. Multi-module, multi-stack fuel cell systems are a key technology for addressing high power demands and complex application scenarios. However, controlling the flow, pressure, and temperature of multi-module fuel cell systems remains challenging, and a single testing platform is insufficient to meet the testing requirements of high-power, multi-stack fuel cell systems. Summary of the Invention

[0006] To overcome the shortcomings of existing testing platforms in controlling the flow, pressure, and temperature of fuel cell systems, this invention provides a testing platform and control method for high-power hybrid fuel cell systems used in locomotives.

[0007] The technical solution adopted by the present invention to solve its technical problem is: a test platform for a high-power compound fuel cell system for locomotives, including a hydrogen supply module, a main cooling circuit, and an auxiliary cooling circuit. The hydrogen supply module, the main cooling circuit, and the auxiliary cooling circuit are respectively connected to the fuel cell system through pipelines. The hydrogen supply module includes a hydrogen circuit, a nitrogen circuit, a flow meter, a medium-pressure sensor, and a manifold. The hydrogen circuit and the nitrogen circuit are both connected to a main pipeline. A flow meter, a medium-pressure sensor, and a manifold are installed sequentially on the main pipeline.

[0008] According to another embodiment of the present invention, the hydrogen circuit further includes a hydrogen delivery pipe, a manual shut-off valve, a high-pressure sensor, a filter, a first-stage pressure reducing valve, a second-stage pressure reducing valve, a second-stage pressure reducing valve, a safety valve, a pressure relief valve, a solenoid valve, and a proportional valve. The manual shut-off valve, the high-pressure sensor, the filter, the second-stage pressure reducing valve, the solenoid valve, and the proportional valve are sequentially installed on the hydrogen delivery pipe. The first-stage pressure reducing valve and the second-stage pressure reducing valve are connected together. The safety valve and the pressure relief valve are connected together between the second-stage pressure reducing valve and the solenoid valve.

[0009] According to another embodiment of the present invention, the nitrogen circuit further includes a nitrogen delivery pipe, a second manual shut-off valve, a second high-pressure sensor, a second filter, a pressure reducing valve, a second medium-pressure sensor, a second safety valve, a second pressure relief valve, and a check valve. The second manual shut-off valve, the second high-pressure sensor, the second filter, the pressure reducing valve, the second medium-pressure sensor, and the check valve are sequentially installed on the nitrogen delivery pipe. The second safety valve and the second pressure relief valve are connected between the second medium-pressure sensor and the check valve.

[0010] According to another embodiment of the present invention, the main cooling circuit further includes a main cooling tower, a temperature sensor, a particulate filter, a main cooling water pump, a manual shut-off valve, and a heat exchanger. The outlet and inlet of the main cooling tower are respectively connected to the first outlet and the first inlet of the heat exchanger via pipelines. The second outlet and the second inlet of the heat exchanger are respectively connected to the fuel cell system via pipelines. The temperature sensor, the particulate filter, and the main cooling water pump are sequentially installed on the pipeline connecting the outlet of the main cooling tower and the first inlet of the heat exchanger.

[0011] According to another embodiment of the present invention, the auxiliary cooling circuit further includes an auxiliary cooling tower, a second particulate filter, an auxiliary cooling water pump, a second heat exchanger, a temperature sensor, the second auxiliary cooling water pump, and a drain valve. The outlet and inlet of the auxiliary cooling tower are respectively connected to the first outlet and the first inlet of the second heat exchanger via pipelines. The second outlet and the second inlet of the second heat exchanger are respectively connected to the fuel cell system via pipelines. The second particulate filter and the auxiliary cooling water pump are sequentially installed on the pipeline between the outlet of the auxiliary cooling water pump and the inlet of the second heat exchanger. A drain valve is installed on the pipeline between the inlet of the auxiliary cooling water pump and the second outlet of the second heat exchanger. A temperature sensor is installed on the pipeline between the second outlet of the second heat exchanger and the fuel cell system. The second auxiliary cooling water pump and a drain valve are installed on the pipeline between the second inlet of the second heat exchanger and the fuel cell system.

[0012] A control method for a test platform of a high-power hybrid fuel cell system for locomotives, comprising the following steps:

[0013] S1. Obtain the number of fuel cell systems currently connected to the test platform and their rated output power;

[0014] S2. Based on the number of fuel cell systems currently connected, open the manual valve of the corresponding hydrogen manifold and control the opening degree of proportional valve one according to the hydrogen pressure requirement at the front end of the fuel cell system.

[0015] S3. Calculate the required heat dissipation of the fuel cell stack based on the number of fuel cell systems currently connected, control the main cooling tower speed based on the temperature sensor readings, and control the main cooling water pump speed based on the temperature sensor difference between the inlet and outlet of the cooling tower, so as to control the cold side water temperature and temperature difference of the heat exchanger within a suitable range.

[0016] According to another embodiment of the present invention, the outlet pressure of the manual valve of the hydrogen manifold is further controlled by PI control, and the opening degree Pv of the proportional valve is adjusted based on the difference between the reading value Pr of the medium pressure sensor and the set pressure value Ps, and the calculation formula is as follows:

[0017]

[0018]

[0019] Where Kp is the proportional gain, which directly amplifies the difference between the current error setpoint and the actual value, and Ki is the integral gain, which accumulates historical errors to eliminate steady-state errors.

[0020] According to another embodiment of the invention, the method further includes feedback control of the main cooling tower rotation speed CRPM based on the temperature sensor reading Tr and the temperature setpoint Ts:

[0021]

[0022] .

[0023] According to another embodiment of the present invention, the method further includes controlling the main cooling water pump speed PRPM based on the linear difference method and the temperature sensor difference between the inlet and outlet of the main cooling tower.

[0024]

[0025]

[0026]

[0027] Wherein, Tin and Tou are the measured inlet and outlet temperatures of the main cooling tower, respectively; ∆Tmin is the minimum setpoint for temperature difference; ∆Tmax is the maximum setpoint for allowable temperature difference; k is the linear difference coefficient; PRPMmin is the minimum allowable speed of the main cooling water pump; and PRPMmax is the maximum allowable speed of the main cooling water pump.

[0028] The beneficial effects of this invention are that it can meet the simultaneous testing requirements of multiple high-power fuel cell systems and achieve stable hydrogen flow, pressure and temperature control. Attached Figure Description

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0031] Figure 1 This is a structural block diagram of the present invention;

[0032] Figure 2 This is a schematic diagram of the hydrogen supply module of the present invention;

[0033] Figure 3 This is a schematic diagram of the main cooling circuit of the present invention;

[0034] Figure 4 This is a schematic diagram of the auxiliary cooling circuit of the present invention;

[0035] In the diagram: 1. Hydrogen supply module; 2. Main cooling circuit; 3. Auxiliary cooling circuit; 11. Manual shut-off valve 1; 12. High-pressure sensor 1; 13. Filter 1; 14. First-stage pressure reducing valve 1; 15. First-stage pressure reducing valve 2; 16. Second-stage pressure reducing valve; 17. Safety valve 1; 18. Pressure relief valve 1; 19. Solenoid valve 1; 20. Proportional valve 1; 21. Manual shut-off valve 2; 22. High-pressure sensor 2; 23. Filter 2; 24. Pressure reducing valve; 25. Medium-pressure sensor 2; 26. Safety valve 2; 27. Pressure relief valve 2; 28. Check valve; 101. Flow meter; 102. Medium-pressure sensor; 103. Manifold; 201. Main cooling tower; 202. Temperature sensor; 203. Particulate filter; 204. Main cooling water pump; 205. Manual shut-off valve 3, 206. Heat exchanger, 301. Auxiliary cooling tower, 302. Particulate filter 2, 303. Auxiliary cooling water pump, 304. Heat exchanger 2, 305. Temperature sensor, 306. Auxiliary cooling water pump 2, 307. Drain manual valve. Detailed Implementation

[0037] Figure 1 This is a structural block diagram of the present invention; Figure 2 This is a schematic diagram of the hydrogen supply module of the present invention; Figure 3 This is a schematic diagram of the main cooling circuit of the present invention; Figure 4 This is a schematic diagram of the auxiliary cooling circuit of the present invention.

[0038] As attached Figure 1 As shown, a test platform for a high-power hybrid fuel cell system for locomotives includes a hydrogen supply module 1, a main cooling circuit 2, and an auxiliary cooling circuit 3. The hydrogen supply module 1, the main cooling circuit 2, and the auxiliary cooling circuit 3 are respectively connected to the fuel cell system through pipelines. The hydrogen supply module 1 includes a hydrogen circuit, a nitrogen circuit, a flow meter 101, a medium-pressure sensor 102, and a manifold 103. The hydrogen circuit and the nitrogen circuit are both connected to a main pipeline, on which the flow meter 101, the medium-pressure sensor 102, and the manifold 103 are installed in sequence.

[0039] The diameter design of the hydrogen supply module 1 should be determined according to the actual flow rate at the working pressure and temperature of the pipe section.

[0040] The actual flow velocity inside a hydrogen pipeline must not exceed 50% of the erosion velocity. Specific requirements vary depending on the application; for stainless steel pipelines, the maximum flow velocity is generally 20-25 m / s. The diameter of the hydrogen pipeline can be calculated using the following formula:

[0041] Q=(πD^2) / 4 υ

[0042] Where Q is the hydrogen flow rate (m³ / s), D is the pipe inner diameter (m), and υ is the hydrogen flow velocity in the pipe (m / s).

[0043] After calculating the hydrogen flow rate in the pipeline using the above formula, it is necessary to verify whether the pressure loss is within the allowable range using hydraulic calculation formulas.

[0044] ΔP=(λLρυ^2) / 2D

[0045] Where: λ is the hydraulic friction coefficient, which is related to the Reynolds number and pipe roughness; ρ is the gas density; and L is the pipe length.

[0046] The hydrogen flow rate design for the hydrogen supply module can be calculated based on the power output of the fuel cell system under test. According to the electrochemical reaction, hydrogen is oxidized at the anode, releasing 2 moles of electrons per mole of hydrogen. Combining Faraday's law and the power-voltage relationship, the formula for calculating the hydrogen volumetric flow rate is derived as follows:

[0047] Q=(S H2 Pe) / (2Vc F)∙22.4∙60

[0048] Among them, S H2 ρ is the hydrogen excess coefficient (usually taken as 1.2~2.0 to ensure sufficient hydrogen supply and avoid waste), Pe is the fuel cell output power (W), Vc is the operating voltage of a single cell (V, usually taken as 0.6~0.7 V to improve efficiency), F is the Faraday constant (96485 C / mol), and 22.4 L / mol is the molar volume of the gas under standard conditions.

[0049] As attached Figure 2 As shown, the hydrogen circuit includes a hydrogen delivery pipe, a manual shut-off valve 11, a high-pressure sensor 12, a filter 13, a primary pressure reducing valve 14, a secondary pressure reducing valve 15, a secondary pressure reducing valve 16, a safety valve 17, a pressure relief valve 18, a solenoid valve 19, and a proportional valve 20. The manual shut-off valve 11, the high-pressure sensor 12, the filter 13, the secondary pressure reducing valve 16, the solenoid valve 19, and the proportional valve 20 are installed sequentially on the hydrogen delivery pipe. The primary pressure reducing valve 14 and the secondary pressure reducing valve 15 are connected between the filter 13 and the secondary pressure reducing valve 16. The safety valve 17 and the pressure relief valve 18 are connected between the secondary pressure reducing valve 16 and the solenoid valve 19.

[0050] Manual shut-off valve 11 is located at the hydrogen cylinder outlet. High-pressure sensor 12 is installed on the pipeline between filter 13 and manual shut-off valve 11 to measure the hydrogen pressure at the hydrogen cylinder outlet. Hydrogen in the cylinder is reduced in pressure by primary pressure reducing valve 14, primary pressure reducing valve 15, and secondary pressure reducing valve 16. Then, the hydrogen pipeline's on / off state and the hydrogen supply pipeline outlet pressure are controlled by solenoid valve 19 and proportional valve 20, respectively. Medium-pressure sensor 102 is located between proportional valve 20 and manifold 103 to measure the proportional valve 20 outlet pressure. A bypass is installed on the pipeline between secondary pressure reducing valve 16 and solenoid valve 19, equipped with safety valve 17 and pressure relief valve 18 for hydrogen release and pipeline safety protection.

[0051] The nitrogen circuit includes a nitrogen delivery pipe, a manual shut-off valve 21, a high-pressure sensor 22, a filter 23, a pressure reducing valve 24, a medium-pressure sensor 25, a safety valve 26, a pressure relief valve 27, and a check valve 28. The nitrogen delivery pipe is sequentially equipped with the manual shut-off valve 21, the high-pressure sensor 22, the filter 23, the pressure reducing valve 24, the medium-pressure sensor 25, and the check valve 28. The safety valve 26 and the pressure relief valve 27 are connected between the medium-pressure sensor 25 and the check valve 28.

[0052] Manual shut-off valve 21 is located at the nitrogen cylinder outlet. High-pressure sensor 22 is installed on the pipeline between filter 23 and manual shut-off valve 21 to measure the nitrogen pressure at the nitrogen cylinder outlet. Next, nitrogen is depressurized by pressure reducing valve 24 and then connected between proportional valve 20 and flow meter 101 for purging the pipeline and fuel cell stack. A one-way valve 28 is installed in the nitrogen branch to prevent hydrogen backflow into the nitrogen branch.

[0053] As attached Figure 3 As shown, the main cooling circuit 2 includes a main cooling tower 201, a temperature sensor 202, a particulate filter 203, a main cooling water pump 204, a manual shut-off valve 205, and a heat exchanger 206. The outlet and inlet of the main cooling tower 201 are respectively connected to the first outlet and the first inlet of the heat exchanger 206 through pipelines. The second outlet and the second inlet of the heat exchanger 206 are respectively connected to the fuel cell system through pipelines. The temperature sensor 202, the particulate filter 203, and the main cooling water pump 204 are sequentially installed on the pipeline connecting the outlet of the main cooling tower 201 and the first inlet of the heat exchanger 206.

[0054] The main cooling circuit 2 dissipates heat from several fuel cell stacks via several heat exchangers 206. The cold side of the heat exchangers 206 is connected to the main cooling tower 201 via pipelines, and the cooling water is driven by the main cooling water pump 204. Each heat exchanger 206 is equipped with a manual shut-off valve 205 at its inlet to control the number of heat exchangers 206 in use.

[0055] As attached Figure 4 As shown, the auxiliary cooling circuit 3 includes an auxiliary cooling tower 301, a second particulate filter 302, an auxiliary cooling water pump 303, a second heat exchanger 304, a temperature sensor 305, a second auxiliary cooling water pump 306, and a drain valve 307. The outlet and inlet of the auxiliary cooling tower 301 are respectively connected to the first outlet and the first inlet of the second heat exchanger 304 via pipelines. The second outlet and the second inlet of the second heat exchanger 304 are respectively connected to the fuel cell system via pipelines. The outlet of the auxiliary cooling water pump 303 is connected to the heat exchanger... A particulate filter 302 and an auxiliary cooling water pump 303 are installed sequentially on the pipeline between the inlet and outlet of the heat exchanger 304. A drain valve 307 is installed on the pipeline between the inlet of the auxiliary cooling water pump 303 and the second outlet of the heat exchanger 304. A temperature sensor 305 is installed on the pipeline between the second outlet of the heat exchanger 304 and the fuel cell system. An auxiliary cooling water pump 306 and a drain valve 307 are installed on the pipeline between the second inlet of the heat exchanger 304 and the fuel cell system.

[0056] The auxiliary cooling circuit 3 dissipates heat from the auxiliary power electronic components of multiple fuel cell systems through several auxiliary cooling circuits 3.

[0057] A control method for a test platform of a high-power hybrid fuel cell system for locomotives, comprising the following steps:

[0058] S1. Obtain the number of fuel cell systems currently connected to the test platform and their rated output power;

[0059] S2. Based on the number of fuel cell systems currently connected, open the hand valve of the corresponding hydrogen manifold 103, and control the opening degree of the proportional valve 20 according to the hydrogen pressure requirement at the front end of the fuel cell system.

[0060] S3. Calculate the required heat dissipation of the fuel cell stack based on the number of fuel cell systems currently connected. Control the speed of the main cooling tower 201 based on the feedback of the temperature sensor 202 reading. Control the speed of the main cooling water pump 204 based on the temperature difference between the inlet and outlet of the cooling tower to control the cold side water temperature and temperature difference of the heat exchanger 206 within a suitable range.

[0061] The outlet pressure of the manual valve of the hydrogen manifold 103 is controlled by PI. The opening degree Pv of the proportional valve 20 is adjusted based on the difference between the reading Pr of the medium pressure sensor 102 and the set pressure value Ps. The calculation formula is as follows:

[0062]

[0063]

[0064] Where Kp is the proportional gain, which directly amplifies the difference between the current error setpoint and the actual value, and Ki is the integral gain, which accumulates historical errors to eliminate steady-state errors.

[0065] According to another embodiment of the present invention, the method further includes feedback control of the main cooling tower 201 rotation speed CRPM based on the temperature sensor 202 reading value Tr and the temperature setpoint Ts:

[0066]

[0067] .

[0068] According to another embodiment of the present invention, the method further includes controlling the rotational speed (PRPM) of the main cooling water pump 204 based on the linear difference method and the differential values ​​from the temperature sensors 202 at the inlet and outlet of the main cooling tower 201.

[0069]

[0070]

[0071]

[0072] Wherein, Tin and Tou are the inlet and outlet temperature measurements of the main cooling tower 201, respectively; ∆Tmin is the minimum setpoint for temperature difference; ∆Tmax is the maximum setpoint for allowable temperature difference; k is the linear difference coefficient; PRPMmin is the minimum allowable speed of the main cooling water pump 204; and PRPMmax is the maximum allowable speed of the main cooling water pump 204.

Claims

1. A test platform for a high-power hybrid fuel cell system for locomotives, characterized in that, The system includes a hydrogen supply module (1), a main cooling circuit (2), and an auxiliary cooling circuit (3). The hydrogen supply module (1), the main cooling circuit (2), and the auxiliary cooling circuit (3) are connected to the fuel cell system through pipelines. The hydrogen supply module (1) includes a hydrogen circuit, a nitrogen circuit, a flow meter (101), a medium-pressure sensor (102), and a manifold (103). The hydrogen circuit and the nitrogen circuit are both connected to the main pipeline. The flow meter (101), the medium-pressure sensor (102), and the manifold (103) are installed sequentially on the main pipeline.

2. The test platform for a high-power hybrid fuel cell system for locomotives according to claim 1, characterized in that, The hydrogen circuit includes a hydrogen delivery pipe, a manual shut-off valve (11), a high-pressure sensor (12), a filter (13), a first-stage pressure reducing valve (14), a second-stage pressure reducing valve (15), a second-stage pressure reducing valve (16), a safety valve (17), a pressure relief valve (18), a solenoid valve (19), and a proportional valve (20). The hydrogen delivery pipe is sequentially equipped with a manual shut-off valve (11), a high-pressure sensor (12), a filter (13), a second-stage pressure reducing valve (16), a solenoid valve (19), and a proportional valve (20). The filter (13) and the second-stage pressure reducing valve (16) are connected by a first-stage pressure reducing valve (14) and a second-stage pressure reducing valve (15). The second-stage pressure reducing valve (16) and the solenoid valve (19) are connected by a safety valve (17) and a pressure relief valve (18).

3. The test platform for a high-power hybrid fuel cell system for locomotives according to claim 1, characterized in that, The nitrogen circuit includes a nitrogen delivery pipe, a manual shut-off valve 2 (21), a high-pressure sensor 2 (22), a filter 2 (23), a pressure reducing valve (24), a medium-pressure sensor 2 (25), a safety valve 2 (26), a pressure relief valve 2 (27), and a check valve (28). The nitrogen delivery pipe is sequentially equipped with a manual shut-off valve 2 (21), a high-pressure sensor 2 (22), a filter 2 (23), a pressure reducing valve (24), a medium-pressure sensor 2 (25), and a check valve (28). The medium-pressure sensor 2 (25) and the check valve (28) are connected by a safety valve 2 (26) and a pressure relief valve 2 (27).

4. The test platform for a high-power hybrid fuel cell system for locomotives according to claim 1, characterized in that, The main cooling circuit (2) includes a main cooling tower (201), a temperature sensor (202), a particulate filter (203), a main cooling water pump (204), a manual shut-off valve (205), and a heat exchanger (206). The outlet and inlet of the main cooling tower (201) are respectively connected to the first outlet and the first inlet of the heat exchanger (206) through pipelines. The second outlet and the second inlet of the heat exchanger (206) are respectively connected to the fuel cell system through pipelines. The temperature sensor (202), the particulate filter (203), and the main cooling water pump (204) are installed sequentially on the pipeline connecting the outlet of the main cooling tower (201) and the first inlet of the heat exchanger (206).

5. The test platform for a high-power hybrid fuel cell system for locomotives according to claim 1, characterized in that, The auxiliary cooling circuit (3) includes an auxiliary cooling tower (301), a second particulate filter (302), an auxiliary cooling water pump (303), a second heat exchanger (304), a temperature sensor (305), a second auxiliary cooling water pump (306), and a drain valve (307). The outlet and inlet of the auxiliary cooling tower (301) are respectively connected to the first outlet and the first inlet of the second heat exchanger (304) via pipelines. The second outlet and the second inlet of the second heat exchanger (304) are respectively connected to the fuel cell system via pipelines. The outlet of the auxiliary cooling water pump (303) is connected to the first outlet and the first inlet of the second heat exchanger (304). A particulate filter 2 (302) and an auxiliary cooling water pump (303) are installed sequentially on the pipe between the inlet of heat exchanger 2 (304). A drain valve (307) is installed on the pipe between the inlet of the auxiliary cooling water pump (303) and the second outlet of heat exchanger 2 (304). A temperature sensor (305) is installed on the pipe between the second outlet of heat exchanger 2 (304) and the fuel cell system. An auxiliary cooling water pump 2 (306) and a drain valve (307) are installed on the pipe between the second inlet of heat exchanger 2 (304) and the fuel cell system.

6. The control method for the test platform of a high-power hybrid fuel cell system for locomotives according to any one of claims 1 to 5, characterized in that, The specific steps are as follows: S1. Obtain the number of fuel cell systems currently connected to the test platform and their rated output power; S2. Based on the number of fuel cell systems currently connected, open the hand valve of the corresponding hydrogen manifold (103) and control the opening degree of proportional valve one (20) according to the hydrogen pressure demand at the front end of the fuel cell system. S3. Calculate the required heat dissipation of the fuel cell stack based on the number of fuel cell systems currently connected. Control the speed of the main cooling tower (201) based on the feedback of the temperature sensor (202) reading. Control the speed of the main cooling water pump (204) based on the temperature difference between the inlet and outlet of the cooling tower (202) to control the cold side water temperature and temperature difference of the heat exchanger (206) within a suitable range.

7. The control method for the test platform of the high-power hybrid fuel cell system for locomotives according to claim 6, characterized in that, The outlet pressure of the hand valve of the hydrogen manifold (103) is controlled by PI. The opening degree Pv of the proportional valve (20) is adjusted according to the difference between the reading value Pr of the medium pressure sensor (102) and the set pressure value Ps. The calculation formula is as follows: ； ； Where Kp is the proportional gain, which directly amplifies the difference between the current error setpoint and the actual value, and Ki is the integral gain, which accumulates historical errors to eliminate steady-state errors.

8. The control method for the test platform of the high-power hybrid fuel cell system for locomotives according to claim 6, characterized in that, Based on the temperature sensor (202) reading Tr and the temperature setpoint Ts, the main cooling tower (201) speed CRPM is controlled by feedback. ； 。 9. The control method for the test platform of the high-power hybrid fuel cell system for locomotives according to claim 6, characterized in that, The main cooling water pump (204) speed PRPM is controlled by the linear difference method and the temperature sensor (202) at the inlet and outlet of the main cooling tower (201); ； ； ； Wherein, Tin and Tou are the inlet and outlet temperature measurements of the main cooling tower (201), respectively; ∆Tmin is the minimum set value of temperature difference; ∆Tmax is the maximum set value of allowable temperature difference; k is the linear difference coefficient; PRPMmin is the minimum allowable speed of the main cooling water pump (204); and PRPMmax is the maximum allowable speed of the main cooling water pump (204).

Images