CN111404184A - Fuel cell test and electric vehicle charging coupling system and control method - Google Patents

Abstract

The invention discloses a fuel cell testing and electric vehicle charging coupling system, which comprises a fuel cell testing unit, an energy storage unit, a charging unit, an energy storage bidirectional converter and an energy management unit, wherein the energy management unit is respectively in communication connection with the fuel cell testing unit, the energy storage unit, the charging unit and the energy storage bidirectional converter; the control method of the fuel cell testing and electric vehicle charging coupling system is also disclosed. The invention avoids the energy waste caused by the conventional resistance load consuming the electric energy generated by the fuel cell system through heat energy, and simultaneously saves the extra electric energy consumption for the resistance load cooling equipment.

Description

Fuel cell test and electric vehicle charging coupling system and control method

technical field

The invention relates to the technical field of fuel cell testing, in particular to a fuel cell testing and electric vehicle charging coupling system and a control method.

Background technique

Large-scale research, validation and testing of fuel cell stacks, fuel cell systems and fuel cell engines are essential steps before fuel cell applications. Since the fuel cell itself is a power generation device that continuously consumes hydrogen, the first solution in the traditional performance test process is to use a resistive load to consume the electrical energy generated by the fuel cell system through thermal energy, resulting in a waste of resources and an increase in cost. . In addition, the commonly used electronic loads also need to dissipate heat such as a cooling tower, a large fan or even an air conditioner during the process of releasing heat energy to ensure the normal operation of the electronic load, so additional power is required. For the fuel cell power system for new energy vehicles, the power of which exceeds 30kW or even as high as 100kW, the test method using electronic load will generate a great waste of electric energy and the test cost will rise.

The second solution is to use a grid-feeding electronic load to feed back the electrical energy output during the fuel cell test to the grid. Although this solution can effectively avoid the heat consumption of the fuel cell during the test and discharge process, due to the complexity and diversity of the test process (such as frequent start-stop loading, acceleration, and test polarization curves, etc.) When feeding power to the power grid under certain circumstances, it will cause serious interference of high-frequency harmonics to the power grid, and it is difficult to deal with it, which seriously affects the power quality of the power grid, and even causes an impact on the power grid.

The third scheme is to obtain hydrogen by electrolyzing water to produce hydrogen from the electrical energy output during the fuel cell testing process and pass it into the fuel cell for recycling. However, the conversion efficiency of hydrogen into electricity during fuel cell operation is generally 50% (based on the low calorific value LHV of hydrogen), while the theoretical electrolysis efficiency of the electricity generated by electrolyzing water to hydrogen again is high (the apparent conversion efficiency is even up to 100% to 122%), but in order to increase the hydrogen production rate in industry, the power conversion efficiency is only 50% to 70% due to factors such as heating and the generated polarization overpotential. Then the complete cycle efficiency of hydrogen→fuel cell→electrolyzer→hydrogen is only 30%, the energy loss exceeds 70%, and the cost of the hydrogen production system by electrolysis (especially the solid electrolyte membrane electrolysis of water with precious metal platinum or iridium as catalyst) Hydrogen production system) is higher and has a shorter lifespan. Therefore, this solution is not economical, and there are problems of complicated system and complicated maintenance.

On the other hand, the current charging technology of electric vehicles based on charging piles still has the following problems: First, the charging energy comes from the grid, and at least 70% of my country's electricity comes from coal, so the application of electric vehicles has not changed the conventional The energy consumption and the impact on environmental pollution only concentrate the pollution sources in thermal power plants; secondly, since the charging of electric vehicles is a non-linear load, harmonic current will be injected into the power grid at the same time during the charging process, which will lead to the degradation of power quality of the power grid and the loss of power to the power grid. The loss increases and the normal capacity of the power transmission and transformation equipment is occupied. It is also necessary to increase the reactive power compensation equipment to stabilize the node voltage, resulting in complicated control and rising equipment cost. A large number of fluctuations come, and the stability of the power supply of the power grid deteriorates.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a fuel cell testing and electric vehicle charging coupling system and control method.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

An embodiment of the present invention provides a fuel cell test and electric vehicle charging coupling system, including a fuel cell test unit, an energy storage unit, a charging unit, an energy storage bidirectional converter, and an energy management unit, the energy management unit is respectively connected to the fuel cell The test unit, the energy storage unit, the charging unit and the energy storage bidirectional converter are connected in communication, and the energy storage unit is respectively electrically connected with the fuel cell test unit, the charging unit and the DC terminal of the energy storage bidirectional converter, and the energy storage unit is electrically connected to the DC terminal of the energy storage bidirectional converter. The AC end of the bidirectional converter is electrically connected with the external power grid.

In the above solution, the fuel cell test unit includes at least one set of fuel cell test benches and unidirectional DC/DC converters, and the DC output end of the fuel cell to be tested in the fuel cell test bench and its corresponding unidirectional DC/DC converter. The input end of the DC converter is electrically connected, and the output end of the unidirectional DC/DC converter is connected to the energy storage unit via a circuit breaker.

In the above solution, the energy storage unit includes an energy storage battery pack and a battery management unit, one input end of the energy storage battery pack is electrically connected to the fuel cell test unit, and the other output end of the energy storage battery pack is connected to the charging unit. The unit is electrically connected, and the energy storage battery pack is also electrically connected to the DC terminal of the energy storage bidirectional converter; the battery management unit is connected to the energy storage battery pack through a low-voltage signal line.

In the above scheme, the energy storage battery pack adopts one or more of lead-acid batteries, lead-carbon batteries, lithium-ion batteries, flow batteries, sodium-sulfur batteries, supercapacitors, lithium titanate batteries, and all-vanadium flow batteries. kind.

In the above solution, the charging unit includes a fast charging distribution cabinet and/or a slow charging distribution cabinet; the input end of the fast charging distribution cabinet and/or the slow charging distribution cabinet is electrically connected to the energy storage unit via an internal circuit breaker. connection, the output end of the fast charging distribution cabinet and/or the slow charging distribution cabinet is respectively connected with the input end of at least one fast charging charging pile and/or the slow charging charging pile, and the energy transmitted from the energy storage unit Electric energy is distributed to each of the fast-charging charging piles and/or the slow-charging charging piles; the fast-charging charging piles and/or the slow-charging charging piles provide a designated DC voltage output port for fast charging and/or slow charging of the electric vehicle.

In the above solution, the energy management unit communicates with the fuel cell test bench and the one-way DC/DC converter in the fuel cell test unit, the battery management unit in the energy storage unit, and the fast charging charging pile in the charging unit respectively through the communication line. and/or the slow charging pile and the energy storage bidirectional converter, respectively, through the low voltage signal line with the circuit breaker of the unidirectional DC/DC converter in the fuel cell test unit, the circuit breaker in the energy storage unit, and the fast charging unit in the charging unit. The circuit breaker of the charging distribution cabinet and/or the slow charging distribution cabinet is connected to the isolating switch in the energy storage bidirectional converter.

The embodiment of the present invention also provides a control method of a fuel cell test and electric vehicle charging coupling system, and the method is realized by the following steps:

In step (1), the energy management unit starts a self-check and confirms that the grid-connected isolating switch of the energy storage bidirectional converter is in a disconnected state, so that the fuel cell test and electric vehicle charging coupling system enters the initial off-grid control mode ;

Step (2), the energy management unit acquires the number of fuel cells to be tested and test parameters in the fuel cell test unit and determines the total amount of electricity Q ₁ generated by the fuel cell during the entire test process, and obtains energy storage through the energy storage unit The SOC of the battery pack and determine the dischargeable amount Q ₂ when the energy storage battery pack is discharged from the current SOC to the set SOC lower limit and the required charge Q′ ₂ when the current SOC is charged to the set SOC upper limit, and obtain the electric vehicle to be charged The total amount of electricity Q ₃ that needs to be charged; then compare the magnitudes between Q ₁ , Q ₂ , Q' ₂ and Q ₃ :

If Q ₁ ≤Q′ ₂ +Q ₃ , and Q ₃ ≤Q ₁ +Q ₂ , enter the steady-state off-grid working mode;

If Q ₁ >Q' ₂ +Q ₃ , or Q ₃ >Q ₁ +Q ₂ , enter the transient grid-connected working mode.

In the above solution, the steady state off-grid working mode is: the energy management unit sends a start signal to the fuel cell test bench in the fuel cell test unit, and performs electrochemical performance test of the fuel cell to be tested according to preset parameters and work steps. At the same time, send a switch-on command to the one-way DC/DC converter corresponding to the fuel cell test bench to convert the electric energy generated by the fuel cell tested online on the fuel cell test bench into the energy generated by the one-way DC/DC converter. The voltage that matches the charging voltage of the energy storage battery pack in the unit is output to the energy storage battery pack; when fast charging and/or slow charging of the electric vehicle is required, the energy management unit assigns the fast charging to the charging unit. The circuit breaker connecting the electric cabinet and/or the slow charging distribution cabinet to the energy storage battery pack sends a closing signal to transmit the electrical energy stored in the energy storage battery pack to the electric power storage unit via the fast charging distribution cabinet and/or the slow charging distribution cabinet. The fast-charging and/or slow-charging charging piles corresponding to the vehicle perform fast charging and/or slow charging for the electric vehicle.

In the above solution, the energy management unit obtains in real time the electricity Q _F generated by the fuel cell during the test, the state of charge SOC of the energy storage battery pack in the energy storage unit, and the total electricity Q _C required for charging the electric vehicle: if Q ₁ <Q′ ₂ and Q ₃ <Q ₂ , then the fuel cell test and the electric vehicle charging are in a decoupled state, which can be performed synchronously or in a time-sharing manner without interfering with each other; if Q′ ₂ ≤Q ₁ ≤Q ′ ₂ +Q ₃ , when the energy management unit detects that Q _F ≥ Q _C or that no electric vehicle needs to be charged, that is, Q _C =0, it will take fuel according to the state of charge SOC of the energy storage battery pack monitored in real time. The scheduling optimization strategy of timely delaying the battery test step to realize the normal energy transfer of the fuel cell test and the electric vehicle charging coupling system; if Q ₂ ≤Q ₃ ≤Q ₁ +Q ₂ , the energy management unit monitors that Q _F < During QC, according to the real _- time monitoring of the state of charge (SOC) of the energy storage battery pack, a scheduling optimization strategy of timely delaying electric vehicle charging is adopted to achieve normal energy transfer between the fuel cell test and the electric vehicle charging coupling system. The charging strategy of delaying slow charging in extreme cases and then delaying fast charging to ensure the normal fast charging of electric vehicles.

In the above solution, the transient grid-connected working mode is as follows: the energy management unit sends a start signal to the fuel cell test bench in the fuel cell test unit, and conducts an electrochemical performance test of the fuel cell to be tested according to preset parameters and work steps. At the same time, a switch-on command is sent to the one-way DC/DC corresponding to the fuel cell test bench to convert the electrical energy generated by the fuel cell tested online on the fuel cell test bench into a The voltage that matches the charging voltage of the energy storage battery pack is output to the energy storage battery pack; when fast charging and/or slow charging of the electric vehicle is required, the energy management unit supplies the fast charging distribution cabinet in the charging unit And/or the circuit breaker connected to the energy storage battery pack by the slow charge distribution cabinet sends a closing signal to transmit the electrical energy stored in the energy storage battery pack to the corresponding electric vehicle via the fast charge distribution cabinet and/or the slow charge distribution cabinet. The fast-charging and/or slow-charging charging piles provided for fast charging and/or slow charging of electric vehicles.

In the above solution, the energy management unit obtains the power Q _F generated by the fuel cell during the test process, the state of charge SOC of the energy storage battery pack in the energy storage unit, and the total power Q _C required for charging the electric vehicle in real time; if Q ₃ >Q ₁ +Q ₂ , when it is detected that Q _F < Q _C In order to realize the normal energy transfer of the fuel cell test and the electric vehicle charging coupling system, and adopt the charging strategy of delaying the slow charging first and then delaying the fast charging in extreme cases to ensure the normal progress of the electric vehicle fast charging; if the electric vehicle charging is delayed in time, the strategy During the process, when the energy management unit monitors that the state of charge (SOC) of the energy storage battery pack has dropped to a set lower limit and the charging of the electric vehicle is not completed, the energy management unit isolates the energy storage bidirectional converter. The switch sends a closing signal to invert the electric energy of the external grid through the energy storage bidirectional converter into a DC voltage matching the charging voltage of the energy storage battery pack, and then outputs it to the energy storage battery pack.

In the above solution, if Q ₁ >Q′ ₂ +Q ₃ , when it is detected that Q _F ≥ Q _C or no electric vehicle needs to be charged, that is, Q _C =0, the energy management unit will The state of charge SOC of the battery pack adopts the scheduling optimization strategy of timely delaying the fuel cell test step to realize the normal energy transfer of the fuel cell test and the electric vehicle charging coupling system; if the energy management is described in the process of the fuel cell test timely delay strategy When the unit monitors that the state of charge SOC of the energy storage battery pack has risen to the set upper limit and the fuel cell test is still in progress, the energy management unit sends a closing signal to the isolation switch of the energy storage bidirectional converter to store the battery. The electric energy stored in the battery pack is converted into a voltage matching the external power grid through the energy storage bidirectional converter and then output to the external power grid.

Compared with the prior art, the present invention outputs the electric energy generated during the electrochemical test of the fuel cell to the charging pile for charging the electric vehicle. energy waste, and at the same time, it also saves extra power consumption for cooling the resistive load; on the other hand, the energy storage unit configured in the fuel cell test and electric vehicle coupling system of the present invention alleviates the high dependence of electric vehicle charging on external power grids , which can ensure that the electric vehicle can still be charged normally during the mains power outage or peak power consumption; moreover, connecting the charging pile directly with the energy storage unit that outputs DC power can save the AC/DC switching power supply components in the traditional charging pile, improving the Improve charging utilization and efficiency, thereby saving electricity costs.

Description of drawings

FIG. 1 is a schematic structural diagram of a fuel cell testing and electric vehicle charging coupling system according to an embodiment of the present invention.

FIG. 2 is a flowchart of a control method of a fuel cell testing and electric vehicle charging coupling system according to an embodiment of the present invention.

Detailed ways

The embodiments of the present invention will be further described below with reference to the accompanying drawings, and the advantages and features of the present invention will become more apparent with the description. However, the embodiments are only exemplary and do not limit the scope of the present invention in any way. It should be understood by those skilled in the art that the details and forms of the technical solutions of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within the protection scope of the present invention.

In addition, in order to better illustrate the present invention, numerous specific details are given in the following detailed description. It will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other embodiments, well-known methods, procedures, components and circuits are not described in detail so as to highlight the gist of the present invention.

An embodiment of the present invention provides a fuel cell test and electric vehicle charging coupling system, as shown in FIG. 1 , which includes a fuel cell test unit 1 , an energy storage unit 2 , a charging unit 3 , and an energy storage bidirectional converter (PCS) 4 And energy management unit (EMS) 5, described energy management unit 5 is respectively connected with fuel cell test unit 1, energy storage unit 2, charging unit 3 and energy storage bidirectional converter 4, and described energy storage unit 2 is respectively connected with The fuel cell test unit 1 , the charging unit 3 and the DC terminal of the energy storage bidirectional converter 4 are electrically connected, and the AC terminal of the energy storage bidirectional converter PCS4 is electrically connected to the external power grid. in,

Specifically, the fuel cell test unit 1 includes a fuel cell test bench 11 and a unidirectional DC/DC converter 12 . The DC output end of the fuel cell to be tested in the fuel cell test bench 11 and its corresponding unidirectional DC The input end of the /DC converter 12 is electrically connected, and the output end of the unidirectional DC/DC converter 12 is connected to the energy storage unit 2 via a circuit breaker.

The fuel cell test bench 11 in the fuel cell test unit 1 is used to test and evaluate the polarization curve, electrochemical impedance spectroscopy (EIS) and electrochemical performance of the fuel cell under various simulated working conditions. The DC/DC converter 12 outputs the electric energy generated by the fuel cell during the test to the energy storage unit 2 after voltage conversion.

Further, the fuel cell test bench 11 in the fuel cell test unit 1 may be a single set or multiple sets to form a fuel cell test bench array, and each of the fuel cell test benches in the fuel cell test bench array The stations 11 work independently and do not interfere with each other; and the number of the one-way DC/DC converters 12 is consistent with the number of the fuel cell test stations 11 and forms a one-to-one correspondence.

Optionally, the fuel cell test bench 11 includes but is not limited to a hydrogen flow test unit, an air flow test unit, a water management unit, a thermal management unit and a control unit, and the tested fuel cells include but are not limited to single fuel cell, Fuel cell stacks, fuel cell systems, fuel cell engines, etc.; moreover, different fuel cells have different configurations of the corresponding fuel cell test benches, as long as the tested fuel cell type and test parameters are the same as the fuel cell test The table can be matched. Similarly, the configuration parameters of the one-way DC/DC converter 12 corresponding to the fuel cell test bench 11 will also vary due to the voltage and current of the fuel cell to be tested, as long as the voltage and current ranges that can be converted are the same The voltage and current output by the fuel cell can be matched. In other words, in the above fuel cell test bench array, the fuel cell test benches 11 may be of the same type or of different types; correspondingly, the unidirectional DC/DC converter 12 may also be of the same type, or It can be of different types, but the input configuration parameters of each unidirectional DC/DC converter 12 must match the electrical output parameters of the fuel cell test bench 11 to which it is connected, and the output configuration parameters must also match those described above. The parameters such as charging voltage and charging current of the energy storage unit 2 are matched.

Specifically, the energy storage unit 2 includes an energy storage battery pack 21 and a battery management unit (BMS) 22 . An input end of the energy storage battery pack 21 is connected to the one-way DC/DC conversion in the fuel cell test unit 1 . The output end of the converter 12 is electrically connected via a circuit breaker, an output end of the energy storage battery pack 21 is electrically connected to the charging unit 3 , and the energy storage battery pack 21 is also electrically connected to the energy storage bidirectional converter 4 . The DC terminal is electrically connected; the battery management unit 22 is connected to the energy storage battery pack 21 through a low-voltage signal line.

On the one hand, the energy storage battery pack 21 receives the DC power generated by the fuel cell in the fuel cell test unit 1 during the test process and the valley power transmitted from the external power grid via the energy storage bidirectional converter 4, and on the other hand. Provide DC power for the charging unit 3 and feed power to the external power grid through the energy storage bidirectional converter 4 and provide power auxiliary services such as peak regulation, frequency regulation and reactive power compensation for the external power grid;

Optionally, the energy storage battery pack 21 adopts one or more of lead-acid batteries, lead-carbon batteries, lithium-ion batteries, flow batteries, sodium-sulfur batteries, and supercapacitors;

Preferably, the energy storage battery pack 21 preferably adopts a lithium titanate battery or an all-vanadium flow battery.

The battery management unit 22 is used to monitor the voltage, current and temperature of the energy storage battery pack 21, accurately estimate the state of charge SOC of the energy storage battery pack 21, and pass the data information collected in real time through the CAN line. The energy is transmitted to the energy management unit 5 , and at the same time, the energy is balanced among the single cells of the energy storage battery pack 21 .

Specifically, the charging unit 3 includes a fast charging power distribution cabinet 31, a fast charging charging pile 33 and/or a slow charging power distribution cabinet 32, and a slow charging charging pile 34; the fast charging power distribution cabinet 31 and/or the slow charging power distribution cabinet 31 The input end of the power distribution cabinet 32 is electrically connected to an output end of the energy storage battery pack 21 of the energy storage unit 2 via an internal circuit breaker, and the output of the fast charging power distribution cabinet 31 and/or the slow charging power distribution cabinet 32 The terminals are respectively connected to the input terminals of at least one of the fast charging piles 33 and/or the slow charging piles 34, and the electric energy transferred from the energy storage unit 2 is distributed to each of the fast charging piles 33 and/or the slow charging piles 34. A charging pile 34; the fast charging charging pile 33 and/or the slow charging charging pile 34 provide a designated DC voltage output port for fast charging and/or slow charging of the electric vehicle.

Specifically, the DC terminal of the energy storage bidirectional converter PCS4 is electrically connected to the energy storage battery pack 21 of the energy storage unit 2 through an isolation switch, and the AC terminal of the energy storage bidirectional converter PCS4 is electrically connected to the energy storage battery pack 21 through the isolation switch. The external power grid is electrically connected to realize bidirectional energy transfer between the energy storage unit 2 and the external power grid through the conversion of AC and DC under certain circumstances.

Specifically, the energy management unit 5 communicates with the fuel cell test bench 11 and the one-way DC/DC converter 12 in the fuel cell test unit 1 , the battery management unit 22 in the energy storage unit 2 , the charging The fast-charging charging pile 33 and/or the slow-charging charging pile 34 and the energy storage bidirectional converter 4 in the unit 3 are connected to the one-way DC/DC converter 12 of the fuel cell test unit 1 through low-voltage signal lines respectively. The circuit breaker, the circuit breaker in the energy storage unit 2, the circuit breaker in the fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 in the charging unit 3 are connected to the isolating switch in the energy storage bidirectional converter 4, for Receive the real-time parameter information of the fuel cell test unit 1, the energy storage unit 2 and the charging unit 3 and send the information to the fuel cell test bench 11 and the one-way DC/DC converter 12 of the fuel cell test unit 1 according to preset commands , the battery management unit 22 of the energy storage unit 2, the fast charging power distribution cabinet 31 and/or the slow charging power distribution cabinet 32 of the charging unit 3, the fast charging charging pile 33 and/or the slow charging charging pile 34, the energy storage bidirectional conversion The control element of the device 4 issues an operation command to manage and dispatch the energy of the entire fuel cell test and electric vehicle charging coupling system to maintain the normal operation of the entire system.

The fuel cell test and electric vehicle charging coupling system works in a steady-state off-grid working mode and a transient grid-connected working mode:

In the steady-state off-grid working mode, the energy management unit 5 sends a start signal to the fuel cell test bench 11 in the fuel cell test unit 1, and performs electrochemical performance test of the fuel cell to be tested according to preset parameters and working steps , the electric energy generated during this period is converted into a voltage matching the charging voltage of the energy storage battery pack 21 in the energy storage unit 2 through the one-way DC/DC converter 12 and then output to the energy storage battery pack 21; When the car is fast charging and/or slow charging, the energy management unit 5 sends a closing signal to the circuit breaker connected to the energy storage battery pack 21 in the fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 in the charging unit 3 signal, the electric energy stored in the energy storage battery pack 21 is transported to the corresponding fast charging pile 33 and/or the slow charging pile 34 of the electric vehicle via the fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 is: Electric vehicles are fast-charging and/or slow-charging. During the whole process of fuel cell testing and electric vehicle charging, the electrical energy generated by the fuel cell is only transmitted between the fuel cell testing unit 1, the energy storage unit 2, and the charging unit 3. The energy storage bidirectional converter 4 is connected to the The energy storage battery pack 21 and the external power grid are always in a disconnected state, and the entire system operates in an island.

In the transient grid-connected working mode, the energy management unit 5 sends a start-up signal to the fuel cell test bench 11 in the fuel cell test unit 1, and performs electrochemical performance test of the fuel cell to be tested according to preset parameters and working steps , the electric energy generated during this period is converted into a voltage matching the charging voltage of the energy storage battery pack 21 in the energy storage unit 2 through the one-way DC/DC converter 12 and then output to the energy storage battery pack 21; When the car is fast charging and/or slow charging, the energy tube unit 5 sends a closing signal to the circuit breaker connected to the energy storage battery pack 21 in the fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 in the charging unit 3 signal, the electric energy stored in the energy storage battery pack 21 is transported to the corresponding fast charging pile 33 and/or the slow charging pile 34 of the electric vehicle via the fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 is: Electric vehicles are fast-charging and/or slow-charging.

During the charging process, the energy management unit 5 obtains in real time the electricity Q _F generated by the fuel cell during the test, the state of charge SOC of the energy storage battery pack 21 in the energy storage unit 2 , and the total electricity Q required for charging the electric vehicle _C : When it is detected that Q _F < Q _C and the state of charge SOC of the energy storage battery pack 21 has dropped to the set lower limit and the charging of the electric vehicle has not been completed, the energy management unit 5 changes the energy storage two-way The isolation switch of the current converter PCS4 sends a closing signal to invert the electric energy of the external grid through the energy storage bidirectional converter 4 into a DC voltage that matches the charging voltage of the energy storage battery pack 21 and then outputs it to the energy storage battery pack 21 for output. Ensure the smooth charging of the electric vehicle; when it is detected that Q _F ≥ Q _C or no electric vehicle needs to be charged, that is, Q _C = 0 and the state of charge SOC of the energy storage battery pack 21 has risen to the set upper limit while the fuel cell test is still During the process, the energy management unit 5 sends a closing signal to the isolation switch of the energy storage bidirectional converter 4 to invert the electric energy stored in the energy storage battery pack 21 into a phase with the external power grid via the energy storage bidirectional converter 4 After matching the voltage, it is output to the external grid. This ensures the orderly and smooth operation of fuel cell testing and electric vehicle charging.

The invention outputs the electric energy generated during the electrochemical test of the fuel cell to the charging pile for charging the electric vehicle. On the one hand, it avoids the waste of energy consumed by the conventional resistive load by consuming the electric energy generated by the fuel cell system through thermal energy, and at the same time saves the energy consumption. In order to reduce the extra power consumption of the resistance type load cooling device; on the other hand, the energy storage unit configured in the fuel cell test and the electric vehicle coupling system of the present invention relieves the high dependence of the electric vehicle charging on the external power grid, and can ensure the power failure in the mains. Or the electric vehicle can still be charged normally during peak power consumption; moreover, connecting the charging pile directly with the energy storage unit that outputs DC power can save the AC/DC switching power supply components in the traditional charging pile, improving the charging utilization rate and efficiency. This saves electricity costs.

In addition, the use of the energy storage unit of the present invention can avoid the serious interference of the high-frequency harmonics of the power grid caused by the usual grid-feeding electronic load, and effectively suppress the influence of the harmonics generated in the charging process of the electric vehicle on the power quality of the external power grid and the large current. The impact on the power grid during fast charging can effectively improve the power factor of the external power grid; on the other hand, it can realize peak shaving, harmonic control and reactive power compensation of the external power grid, and improve the power quality of the power grid; at the same time, the use of energy storage batteries The group can also bring additional benefits to the enterprise through power auxiliary services such as valley power consumption and peak frequency regulation.

The embodiment of the present invention also provides a method for controlling a fuel cell testing and electric vehicle charging coupling system, as shown in FIG. 2 , the method is implemented by the following steps:

In step 200, the energy management unit 5 starts a self-check, and confirms that the grid-connected isolating switch of the energy storage bidirectional converter 4 is in a disconnected state, so that the fuel cell test and electric vehicle charging coupling system enters the initial off-grid control mode. Then go to step 201 .

In step 201, the energy management unit 5 obtains the number of fuel cells to be tested and test parameters in the fuel cell test unit 1 to calculate the total amount of electricity Q ₁ generated by the fuel cell in the entire test process, and the energy storage unit In step 2, the battery management unit 22 obtains the SOC of the energy storage battery pack 21 to calculate the dischargeable amount Q ₂ when the energy storage battery pack 21 is discharged from the current SOC to the set SOC lower limit and when it is charged from the current SOC to the set SOC upper limit Obtain the total amount of electricity _Q3 required to be charged by the electric vehicle to be charged Q'₂; then compare the magnitudes between Q ₁ , Q ₂ , Q' ₂ and Q ₃ and enter step 202 .

In step 202, when the energy management unit 5 detects that Q ₁ ≤ Q' ₂ +Q ₃ and Q ₃ ≤ Q ₁ +Q ₂ , it will enter step 210 , that is, enter the steady-state off-grid working mode; when detecting When Q ₁ >Q' ₂ +Q ₃ or Q ₃ >Q ₁ +Q ₂ , enter step 220 , that is, enter the transient grid-connected working mode.

In step 210, the energy management unit 5 sends a start-up signal to the fuel cell test bench 11 in the fuel cell test unit 1, performs electrochemical performance test of the fuel cell to be tested according to preset parameters and steps, and simultaneously tests the fuel cell The one-way DC/DC converter 12 corresponding to the bench 11 sends a switch-on command to convert the electrical energy generated by the fuel cells tested online on the fuel cell test bench 11 into the same energy as the energy storage unit through the unidirectional DC/DC converter 12. 2. The voltage that matches the charging voltage of the energy storage battery pack 21 is output to the energy storage battery pack 21; when fast charging and/or slow charging of the electric vehicle is required, the energy management unit 5 supplies the charging unit 3 The medium and fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 are connected to the circuit breaker of the energy storage battery pack 21 to send a closing signal, and the electrical energy stored in the energy storage battery pack 21 is passed through the fast charging distribution cabinet 31 and/or Or the slow-charging distribution cabinet 32 is delivered to the fast-charging charging pile 33 and/or the slow-charging charging pile 34 corresponding to the electric vehicle to perform fast charging and/or slow charging for the electric vehicle. During the whole process of fuel cell testing and electric vehicle charging, the electrical energy generated by the fuel cell is only transmitted between the fuel cell testing unit 1, the energy storage unit 2, and the charging unit 3. The grid-connected isolating switch is always off, and the entire system operates in an island.

Meanwhile, the energy management unit 5 obtains, in real time, the amount of electricity Q _F generated by the fuel cell during the test process, and the energy stored in the energy storage unit 2 under the premise that Q ₁ ≤Q′ ₂ +Q ₃ and Q ₃ ≤ Q ₁ +Q ₂ . The state of charge SOC of the battery pack 21 and the total amount of electricity QC required for charging the electric vehicle are further compared, and the magnitude relationship between _{Q 1} , Q ₂ , Q' ₂ and Q ₃ and between Q _F and _QC and Existing permutations and combinations, then go to step 211 .

In step 211 , the energy management unit 5 starts to detect whether there is a situation where Q ₁ <Q′ ₂ and Q ₃ <Q ₂ : if so, go to step 212 , if not, go to step 213 .

In step 212, the test of the fuel cell and the charging of the electric vehicle are in a decoupled state, which can be performed synchronously or in a time-sharing manner without interfering with each other.

In step 213, the energy management unit 5 starts to detect whether there is a situation where Q' _{2 ≤Q 1} ≤ Q' ₂ +Q ₃ and Q _F ≥ QC or _QC =0: if so, go to step 214 , if If it does not exist, go to step 215 .

In step 214, the energy management unit 5 adopts a scheduling optimization strategy of timely delaying the fuel cell test steps according to the state of charge (SOC) of the energy storage battery pack 21 monitored in real time, so as to realize the fuel cell test and electric vehicle charging Normal energy transfer for coupled systems.

In step 215 , the energy management unit 5 starts to detect whether there is a situation where Q ₂ ≤ Q ₃ ≤ Q ₁ +Q ₂ and Q _F < _QC : if so, go to step 216 , if not, return to step 211 .

In step 216, the energy management unit 5 adopts a scheduling optimization strategy of timely delaying electric vehicle charging according to the state of charge (SOC) of the energy storage battery pack 21 monitored in real time to realize a fuel cell test and electric vehicle charging coupling system The normal energy transfer, and the charging strategy of delaying the slow charging first and then delaying the fast charging in extreme cases is adopted to ensure the normal fast charging of electric vehicles.

In step 220, the energy management unit 5 sends a start-up signal to the fuel cell test bench 11 in the fuel cell test unit 1, performs electrochemical performance test of the fuel cell to be tested according to preset parameters and steps, and simultaneously tests the fuel cell The one-way DC/DC converter 12 corresponding to the bench 11 sends a switch-on command to convert the electrical energy generated by the fuel cells tested online on the fuel cell test bench 11 into the same energy as the energy storage unit through the unidirectional DC/DC converter 12. 2. The voltage that matches the charging voltage of the energy storage battery pack 21 is output to the energy storage battery pack 21; when fast charging and/or slow charging of the electric vehicle is required, the energy management unit 5 supplies the charging unit 3 The medium and fast charging distribution cabinet 31 and/or the slow charging distribution cabinet 32 are connected to the circuit breaker of the energy storage battery pack 21 to send a closing signal, and the electrical energy stored in the energy storage battery pack 21 is passed through the fast charging distribution cabinet 31 and/or Or the slow-charging distribution cabinet 32 is delivered to the fast-charging charging pile 33 and/or the slow-charging charging pile 34 corresponding to the electric vehicle to perform fast charging and/or slow charging for the electric vehicle.

At the same time, the energy management unit 5 obtains, in real time, the amount of electricity Q _F generated by the fuel cell during the test process, and the energy stored in the energy storage unit 2 under the premise of Q ₁ >Q′ ₂ +Q ₃ or Q ₃ >Q ₁ +Q ₂ The state of charge SOC of the battery pack 21 and the total amount of electricity _QC required for charging the electric vehicle, and further compare the magnitude relationship between Q _F and _QC and the relationship between Q ₁ >Q' ₂ +Q ₃ or Q ₃ >Q ₁ +Q ₂ existing permutations and combinations, and then go to step 221.

In step 221 , the energy management unit 5 starts to detect whether there is a situation where Q ₃ >Q ₁ +Q ₂ and Q _F < _QC : if so, go to step 222 , if not, go to step 225 .

In step 222 , the energy management unit 5 continues to detect whether the state of charge SOC of the energy storage battery pack 21 drops to the set lower limit: if not, go to step 223 , and if so, go to step 224 .

In step 223, the grid-connected isolating switch of the energy storage bidirectional converter 4 continues to be in an off state, and the energy management unit 5 adopts the electric power according to the state of charge SOC of the energy storage battery pack 21 monitored in real time. The scheduling optimization strategy of timely delaying vehicle charging to realize the normal energy transfer of fuel cell test and electric vehicle charging coupling system, and adopting the charging strategy of delaying slow charging first and then delaying fast charging in extreme cases to ensure the normal operation of electric vehicle fast charging .

In step 224 , if the charging of the electric vehicle is not completed, the energy management unit 5 sends a closing signal to the isolation switch of the energy storage bidirectional converter 4 to invert the electric energy of the external grid via the energy storage bidirectional converter 4 A DC voltage that matches the charging voltage of the energy storage battery pack 21 is output to the energy storage battery pack 21 to ensure smooth charging of the electric vehicle.

In step 225, the energy management unit 5 starts to detect whether there is a situation where Q ₁ >Q' ₂ +Q ₃ and Q _F ≥ Q _C or Q _C =0: if it exists, go to step 226 , if not, return to Step 221.

In step 226 , the energy management unit 5 continues to detect whether the state of charge SOC of the energy storage battery pack 21 rises to the set upper limit: if not, go to step 227 , and if so, go to step 228 .

In step 227, the grid-connected isolating switch of the energy storage bidirectional converter 4 continues to be in an off state, and the energy management unit 5 takes fuel according to the state of charge SOC of the energy storage battery pack 21 monitored in real time. The scheduling optimization strategy of timely delay of battery test steps to realize the normal energy transfer of fuel cell test and electric vehicle charging coupling system.

In step 228, if the fuel cell test is still in progress, the energy management unit 5 sends a closing signal to the isolation switch of the energy storage bidirectional converter 4 to convert the electric energy stored in the energy storage battery pack 21 through the energy storage bidirectional converter. The inverter 4 is inverted to a voltage matching the external power grid and then output to the external power grid, thereby ensuring the orderly and stable operation of the fuel cell test and the charging of the electric vehicle.

The contents of the embodiments of the present invention are disclosed as above. However, the present embodiments are not intended to limit the scope of the present invention. Simple equivalent changes and modifications made according to the claims and descriptions of the present invention still belong to the technical solutions of the present invention. within the range.

Claims (12)

1. a fuel cell test and electric vehicle charging coupling system, is characterized in that, comprises fuel cell test unit, energy storage unit, charging unit, energy storage bidirectional converter and energy management unit, and described energy management unit is respectively connected with fuel The battery test unit, the energy storage unit, the charging unit and the energy storage bidirectional converter are connected in communication, the energy storage unit is respectively electrically connected with the fuel cell test unit, the charging unit and the DC terminal of the energy storage bidirectional converter, and the energy storage unit is electrically connected to the DC terminal of the energy storage bidirectional converter. The AC end of the bidirectional converter is electrically connected with the external power grid. 2 . The fuel cell test and electric vehicle charging coupling system according to claim 1 , wherein the fuel cell test unit comprises at least one set of fuel cell test benches and a unidirectional DC/DC converter, and the fuel cell test The DC output end of the fuel cell to be tested in the test bench is electrically connected to the corresponding input end of the unidirectional DC/DC converter, and the output end of the unidirectional DC/DC converter is connected to the energy storage unit via a circuit breaker. 3. The fuel cell test and electric vehicle charging coupling system according to claim 1 or 2, wherein the energy storage unit comprises an energy storage battery pack and a battery management unit, and an input end of the energy storage battery pack is electrically connected with the fuel cell test unit, the other output end of the energy storage battery pack is electrically connected with the charging unit, and the energy storage battery pack is also electrically connected with the DC end of the energy storage bidirectional converter; the battery management unit It is connected with the energy storage battery pack through a low-voltage signal line. 4. The fuel cell test and electric vehicle charging coupling system according to claim 3, wherein the energy storage battery pack adopts lead-acid battery, lead-carbon battery, lithium ion battery, flow battery, sodium-sulfur battery, One or more of supercapacitors, lithium titanate batteries, and all-vanadium flow batteries. 5. The fuel cell testing and electric vehicle charging coupling system according to claim 4, wherein the charging unit comprises a fast charging distribution cabinet and/or a slow charging distribution cabinet; the fast charging distribution cabinet and /or the input end of the slow charging distribution cabinet is electrically connected to the energy storage unit via the internal circuit breaker, and the output end of the fast charging distribution cabinet and/or the slow charging distribution cabinet is respectively connected to at least one fast charging charging pile and/or The input end of the slow charging pile is connected, and the electric energy transferred from the energy storage unit is distributed to each of the fast charging and/or slow charging piles; the fast charging and/or slow charging piles Provides a designated DC voltage output port for fast and/or slow charging of electric vehicles. 6 . The fuel cell test and electric vehicle charging coupling system according to claim 5 , wherein the energy management unit communicates with the fuel cell test bench and the one-way DC/DC conversion in the fuel cell test unit through a communication line, respectively. 7 . The battery management unit in the energy storage unit, the fast charging charging pile and/or the slow charging charging pile in the charging unit, and the energy storage two-way converter are connected, respectively, through the low-voltage signal line with the one-way DC/DC/DC in the fuel cell test unit. The circuit breaker of the DC converter, the circuit breaker in the energy storage unit, the circuit breaker of the fast charging distribution cabinet and/or the slow charging distribution cabinet in the charging unit are connected with the isolating switch in the energy storage bidirectional converter. 7. A control method for a fuel cell test and an electric vehicle charging coupling system, characterized in that the method is realized by the following steps: In step (1), the energy management unit starts a self-check and confirms that the grid-connected isolating switch of the energy storage bidirectional converter is in a disconnected state, so that the fuel cell test and electric vehicle charging coupling system enters the initial off-grid control mode ; Step (2), the energy management unit acquires the number of fuel cells to be tested and test parameters in the fuel cell test unit and determines the total amount of electricity Q ₁ generated by the fuel cell during the entire test process, and obtains energy storage through the energy storage unit The SOC of the battery pack and determine the dischargeable amount Q ₂ when the energy storage battery pack is discharged from the current SOC to the set SOC lower limit and the required charge Q′ ₂ when the current SOC is charged to the set SOC upper limit, and obtain the electric vehicle to be charged The total amount of electricity _Q3 that needs to be charged; then compare the magnitudes between Q1, _Q2 , _Q'2 and _{Q3 :} If Q ₁ ≤Q′ ₂ +Q ₃ , and Q ₃ ≤Q ₁ +Q ₂ , enter the steady-state off-grid working mode; If Q ₁ >Q' ₂ +Q ₃ , or Q ₃ >Q ₁ +Q ₂ , enter the transient grid-connected working mode. 8 . The control method of the fuel cell test and electric vehicle charging coupling system according to claim 7 , wherein the steady state off-grid working mode is: the energy management unit supplies the fuel cell in the fuel cell test unit to the fuel cell in the fuel cell test unit. 9 . The test bench sends a start signal to test the electrochemical performance of the fuel cell to be tested according to the preset parameters and working steps, and at the same time sends a turn-on command to the one-way DC/DC converter corresponding to the fuel cell test bench to test the fuel cell test bench online. The electric energy generated by the fuel cell is converted into a voltage matching the charging voltage of the energy storage battery pack in the energy storage unit through a one-way DC/DC converter and then output to the energy storage battery pack; During charging and/or slow charging, the energy management unit sends a closing signal to the circuit breaker connected to the energy storage battery pack in the fast charging distribution cabinet and/or the slow charging distribution cabinet in the charging unit, and the energy storage battery The electrical energy stored in the group is delivered to the corresponding fast charging pile and/or slow charging pile for the electric vehicle via the fast charging distribution cabinet and/or the slow charging distribution cabinet for fast charging and/or slow charging of the electric vehicle. 9 . The control method of the fuel cell test and electric vehicle charging coupling system according to claim 8 , wherein the energy management unit acquires the power Q _F generated by the fuel cell during the test in real time, and the energy stored in the energy storage unit The state of charge SOC of the battery pack and the total amount of electricity _QC required for charging the electric vehicle: if Q ₁ <Q′ ₂ and Q ₃ <Q ₂ , the fuel cell test and the electric vehicle charging are in a decoupled state, either It can be carried out synchronously or in time division without interfering with each other; if Q′ ₂ ≤Q ₁ ≤Q′ ₂ +Q ₃ , when the energy management unit detects that Q _F ≥ Q _C or no electric vehicle needs to be charged, that is Q _C When = 0, according to the state of charge SOC of the energy storage battery group monitored in real time, the scheduling optimization strategy of timely delaying the fuel cell test step is adopted to realize the normal energy transfer between the fuel cell test and the electric vehicle charging coupling system; if Q ₂ ≤Q ₃ ≤ Q ₁ +Q ₂ , when the energy management unit detects that Q _F <Q _C , the energy management unit adopts the timely delay of electric vehicle charging according to the state of charge SOC of the energy storage battery pack monitored in real time The scheduling optimization strategy is used to realize the normal energy transfer of the fuel cell test and the electric vehicle charging coupling system, and the charging strategy that delays the slow charging first and then delays the fast charging in extreme cases is adopted to ensure the normal fast charging of the electric vehicle. 10 . The control method of the fuel cell test and electric vehicle charging coupling system according to claim 7 , wherein the transient grid-connected working mode is: the energy management unit supplies the fuel cell in the fuel cell test unit to the fuel cell in the fuel cell test unit. The test bench sends a start signal to test the electrochemical performance of the fuel cell to be tested according to the preset parameters and working steps, and at the same time sends a turn-on command to the one-way DC/DC corresponding to the fuel cell test bench to test the fuel on the fuel cell test bench online. The electric energy generated by the battery is converted into a voltage matching the charging voltage of the energy storage battery pack in the energy storage unit through a one-way DC/DC converter and then output to the energy storage battery pack; it is necessary to fast charge and charge the electric vehicle. / or during slow charging, the energy management unit sends a closing signal to the circuit breaker connected to the energy storage battery pack in the fast charging distribution cabinet and/or the slow charging distribution cabinet in the charging unit, and the energy storage battery pack is connected to the circuit breaker. The stored electrical energy is transported to the corresponding fast-charging and/or slow-charging charging piles for the electric vehicle via the fast-charging distribution cabinet and/or the slow-charging distribution cabinet for fast-charging and/or slow-charging the electric vehicle. 11. The control method of the fuel cell test and electric vehicle charging coupling system according to claim 10, wherein the energy management unit acquires the power Q _F generated by the fuel cell during the test process in real time, and the energy stored in the energy storage unit is stored in real time. The state of charge SOC of the battery pack and the total amount of electricity QC required for charging the electric vehicle; if Q ₃ >Q ₁ +Q ₂ , when it is detected that Q _{F < QC} The state of charge SOC of the energy storage battery pack adopts the scheduling optimization strategy of timely delaying the charging of the electric vehicle to realize the normal energy transfer of the fuel cell test and the charging coupling system of the electric vehicle, and adopts the priority to delay the slow charging and then delay the fast charging in extreme cases. charging strategy to ensure the normal fast charging of the electric vehicle; if the energy management unit detects that the state of charge SOC of the energy storage battery pack has dropped to the set lower limit during the process of the electric vehicle charging timely delay strategy, the electric vehicle When the charging is not completed, the energy management unit sends a closing signal to the isolation switch of the energy storage bidirectional converter to invert the electric energy of the external grid through the energy storage bidirectional converter to charge the energy storage battery pack. The DC voltage that matches the voltage is output to the energy storage battery pack. 12 . The control method of the fuel cell testing and electric vehicle charging coupling system according to claim 11 , wherein if Q ₁ >Q′ ₂ +Q ₃ , when it is detected that Q _F ≥ Q _C or there is no need for electric vehicles When charging, that is, when Q _C = 0, the energy management unit adopts the scheduling optimization strategy of timely delaying the fuel cell test step according to the state of charge SOC of the energy storage battery group monitored in real time, so as to realize the fuel cell test and the electric vehicle. The normal energy transfer of the charging coupling system; if the energy management unit monitors that the state of charge SOC of the energy storage battery pack has risen to the set upper limit during the fuel cell test timely delay strategy process and the fuel cell test is still in progress, The energy management unit sends a closing signal to the isolation switch of the energy storage bidirectional converter to invert the electric energy stored in the energy storage battery pack to a voltage matching the external grid through the energy storage bidirectional converter and then output it to the external grid .

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