Micro-grid energy storage system and method based on diesel locomotive testboard energy recovery

Abstract

The invention discloses a micro-grid energy storage system and method based on diesel locomotive testboard energy recovery, and the system comprises an energy recovery micro-grid controller, an energy storage bidirectional inverter, a battery subsystem, and a water resistance device, and the energy recovery micro-grid controller comprises a diesel locomotive test mode control unit and an energy storage peak load shifting operation mode control unit. Electric energy is recovered during testing of the diesel locomotive; meanwhile, the recovered electric energy is processed according to in-plant loads and energy storage conditions; and when the internal combustion locomotive is not tested, according to the set peak-valley charging and discharging curve, valley-time low-electricity-price charging and peak-time high-electricity-price discharging are achieved. The electric energy output in the testing process of the diesel locomotive can be recycled, meanwhile, a corresponding control strategy is formulated through the energy recycling system, real-time load regulation and control of a factory area can be conducted, peak-valley economical operation can be conducted through the energy storage system, valley-time low-electricity-price charging and peak-time high-electricity-price discharging are achieved, and the power utilization economical efficiency of the factory is improved.

Description

Technical Field

[0001] The invention relates to a microgrid energy storage system and method based on energy recovery of a diesel locomotive test bench, belonging to the technical field of diesel locomotive test energy recovery. Background Art

[0002] In industrial production, energy is an indispensable resource in the production process. Energy such as electricity and fuel plays an important role in many production links, providing necessary conditions such as power, heating, and lighting for machinery and equipment. However, with the expansion of industrial scale and the upgrading of production methods, energy consumption has also increased, bringing great pressure to the environment and resources. Therefore, saving energy and reducing energy consumption has become an urgent task in the current manufacturing industry.

[0003] The energy waste in the production process of diesel locomotives is particularly prominent. A large amount of energy generated during the testing of diesel locomotives is converted into invalid heat energy and discharged into the environment, causing a huge waste of energy and finances.

[0004] At the same time, with the rapid development of new energy sources such as wind and solar energy, microgrid energy storage systems play an important role in the field of power consumption and regulation. New energy storage technologies are developing in a diversified manner, accelerating iterations, and continuously expanding application scenarios. New energy storage has shifted from pilot demonstrations to large-scale commercial use, ushering in a golden period of rapid development.

[0005] In order to address the problem of energy waste in the production process of diesel locomotives, a microgrid energy storage system based on energy recovery from diesel locomotive test benches is proposed. The excess electric energy generated during the production and testing of diesel locomotives is connected to the microgrid energy storage system as recyclable energy, realizing energy recovery for the diesel locomotive test bench, and creating a new application field for microgrid energy storage. Summary of the invention

[0006] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a microgrid energy storage system based on energy recovery from a diesel locomotive test bench.

[0007] Technical solution: To achieve the above purpose, the technical solution adopted by the present invention is:

[0008] A microgrid energy storage system based on energy recovery of a diesel locomotive test bench includes an energy recovery microgrid controller, an energy storage bidirectional inverter, a battery subsystem, and a water resistance device. The energy recovery microgrid controller includes a diesel locomotive test mode control unit and an energy storage peak shaving and valley filling operation mode control unit, wherein:

[0009] The diesel locomotive test mode control unit is used to start the energy storage bidirectional inverter to recover electric energy when the diesel locomotive is tested. At the same time, the size of the load in the factory is judged. If the load in the factory allows, the recovered electric energy is given priority to the load in the factory. When the load in the factory cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy. When neither the load in the factory nor the battery subsystem can absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes it.

[0010] The energy storage peak shaving and valley filling operation mode control unit is used to control the charging of the battery subsystem at a low electricity price during valley hours and the discharging of the battery subsystem at a high electricity price during peak hours according to the set peak-valley charging and discharging curve when the diesel locomotive is not being tested.

[0011] Preferably, the diesel locomotive test mode control unit performs test control by the following formula:

[0012]

[0013] Among them, P PCS Indicates PCS startup mode, P PCS =1 means starting PCS, P PCS =0 means not starting PCS, n means speed, S PCS Indicates PCS status, S PCS =0 means PCS is in shutdown state, S PCS =1 indicates PCS working state; H indicates operation mode, H=1,2,3,4,5,6, H=1 indicates operation mode 1, operation mode 1 is P E =P DC , P W →0; H=2 indicates operation mode 2, which is P E =0; H=3 indicates operation mode 3, which is P E =P DC , P B =-(P DC -P Load ),P W →0; H=4 indicates operation mode 4, which is P E =P DC , P B =0,P W →0; H=5 means operation mode 2, operation mode 5 is P E =P Load -P B,1 , P B =0,P W =P DC -P E; H = 6 means operation mode 6, operation mode 6 is P E =P DC , P B =0,P W →0;P E represents the target power of the diesel locomotive branch of the energy storage bidirectional inverter, P DC Indicates the output power of the internal combustion engine, P W Indicates the power of the water blocking device, → indicates the tendency, P B represents the target power of the battery branch of the energy storage bidirectional inverter, SOC represents the battery power percentage, P Load Indicates load power, P B,1 Indicates the current power of the battery branch of the energy storage bidirectional inverter, P E,1 Indicates the current power of the diesel locomotive branch of the energy storage bidirectional inverter.

[0014] Preferably: the energy recovery microgrid controller includes an information collection unit, which is used to collect load control information, internal combustion engine speed, rectifier outlet voltage, rectifier outlet current, energy storage information, and plant load. The diesel locomotive test mode control unit is used to detect whether the speed of the diesel locomotive is greater than 0 and judge that the energy storage bidirectional inverter is in a shutdown state based on the energy storage information, then the grid starts the energy storage bidirectional inverter and sets the initial power of the energy storage bidirectional inverter to 0. According to the rectifier outlet voltage and the rectifier outlet current, it is detected whether the diesel locomotive generates output power. If the diesel locomotive has generated output power, the target power of the diesel locomotive branch of the energy storage bidirectional inverter is adjusted to be equal to the output power of the diesel locomotive, and the water resistance device is gradually withdrawn. The SOC range of the energy storage battery is determined based on the energy storage information. If the battery SOC is less than 80%, continue to determine whether the current diesel locomotive power is greater than the current plant load. If it is, set the energy storage bidirectional inverter battery branch to charge the battery, and the charging power is the diesel locomotive power minus the current plant load. Otherwise, the energy storage bidirectional inverter battery branch is set to 0 to stop charging. If the battery SOC is greater than 80%, set the energy storage bidirectional inverter battery branch power to 0 to stop charging. If the energy storage bidirectional inverter diesel locomotive branch discharge power to the grid is greater than the current plant load at this time, limit the current energy storage bidirectional inverter diesel locomotive branch target value to the load value, and at the same time lower the water resistance plate, so that the water resistance acts as the remaining load.

[0015] Preferably: the energy storage peak shaving and valley filling operation mode control unit first determines the operation mode of the energy storage bidirectional inverter. If the energy storage bidirectional inverter is in the grid-connected operation state, it continues; otherwise, the energy storage bidirectional inverter is started to be grid-connected. Read the current battery planned power value. Determine whether the battery SOC is in the allowable range. If the battery SOC is in the allowable range, the planned power output is performed. If the battery SOC is greater than the upper limit value and the battery planned power is charging, the battery power is set to 0. If the battery SOC is greater than the upper limit value and the battery planned power is discharging, the planned power output is performed. If the battery SOC is less than the lower limit value and the battery planned power is discharging, the battery power is set to 0. If the battery SOC is less than the lower limit value and the battery planned power is charging, the planned power output is performed.

[0016] Preferably: the energy storage bidirectional inverter is used to convert stored direct current into alternating current.

[0017] Preferably: the energy storage bidirectional inverter is provided with a plurality of battery control modules, and each battery control module independently controls a battery pack.

[0018] Preferably: the battery subsystem comprises a battery pack and a battery management module BMS, and the battery management module BMS is used to monitor and manage the status and performance of the battery pack.

[0019] Optimum: The battery branch power of the energy storage bidirectional inverter and the internal combustion engine branch power should be 1.2 times greater than the full power of the internal combustion locomotive. The battery capacity should be 2-4 times the rated power of the battery branch of the energy storage inverter.

[0020] Another object of the present invention is to provide an energy recovery method of a microgrid energy storage system based on energy recovery of a diesel locomotive test bench, using the microgrid energy storage system based on energy recovery of a diesel locomotive test bench, comprising the following steps:

[0021] Step S1, the diesel locomotive is installed on the test bench, and the starter motor is physically connected to the diesel locomotive drive shaft. The AC output end of the diesel locomotive synchronous generator is connected to the AC input end of the rectifier. The DC output end of the rectifier is connected to the positive and negative plates of the water resistance device.

[0022] Step S2, the rectifier outlet is connected to the DC branch of the energy storage bidirectional inverter. The battery subsystem is connected to another DC branch of the energy storage bidirectional inverter. The AC end of the energy storage bidirectional inverter is connected to the large power grid of the factory area.

[0023] Step S3, the energy recovery microgrid controller communicates with the test bench tachometer, DC voltmeter, and DC ammeter through the secondary communication cable to collect the speed, rectifier outlet voltage, and rectifier current. The energy recovery microgrid controller controls the lifting of the water resistance plate through the secondary cable. The energy recovery microgrid controller collects and controls the operation of the energy storage bidirectional inverter equipment through the GOOSE communication network. CT and PT mutual inductors are installed at the plant load to collect plant load information and send it to the energy recovery microgrid controller.

[0024] Step S4, during the diesel locomotive test, the diesel engine speed, generator excitation current, and system load are controlled by the test console to adjust the output voltage and current to meet the test point requirements. The system load includes water resistance and energy storage bidirectional inverter. The specific load proportion distribution is determined by the control method of the energy recovery microgrid controller. The control method of the energy recovery microgrid controller includes the diesel locomotive test mode and the energy storage peak shaving and valley filling operation mode.

[0025] Step S5, the diesel locomotive test mode is: when the diesel locomotive is tested, the energy storage bidirectional inverter is started to recover electric energy. At the same time, the size of the load in the factory is judged. If the load in the factory allows, the recovered electric energy is used by the load in the factory first. When the load in the factory cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy. When neither the load in the factory nor the battery subsystem can absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes it.

[0026] Step S6, the energy storage peak shaving and valley filling operation mode is: when the diesel locomotive is not tested, according to the set peak-valley charge and discharge curve, the battery subsystem is controlled to charge at a low electricity price during valley hours and to discharge at a high electricity price during peak hours.

[0027] Preferably, the diesel locomotive test mode in step S5 includes the following steps:

[0028] Step S501, detect whether there is a diesel locomotive platform in use, and if so, detect the relevant information of the corresponding platform.

[0029] Step S502, detect whether the rotation speed of the diesel locomotive is greater than 0 and the energy storage bidirectional inverter is in a shutdown state. If the conditions are met, start the energy storage bidirectional inverter and set the initial power of the energy storage bidirectional inverter to 0.

[0030] Step S503, detecting whether the diesel locomotive generates output power according to the rectifier output voltage and the rectifier output current. If the diesel locomotive has generated output power, adjusting the target power of the diesel locomotive branch of the energy storage bidirectional inverter to be equal to the output power of the diesel locomotive, and gradually exiting the water resistance device.

[0031] Step S504, determine the SOC range of the energy storage battery according to the energy storage information. If the battery SOC is less than 80%, continue to determine whether the current diesel locomotive power is greater than the current plant load. If it is, set the energy storage bidirectional inverter battery branch to charge the battery, and the charging power is the diesel locomotive power minus the current plant load. Otherwise, the energy storage bidirectional inverter battery branch is set to 0 to stop charging. If the battery SOC is greater than 80%, set the energy storage bidirectional inverter battery branch power to 0 to stop charging. If the energy storage bidirectional inverter diesel locomotive branch discharge power to the grid is greater than the current plant load at this time, limit the current energy storage bidirectional inverter diesel locomotive branch target value to the load value, and at the same time lower the water resistance plate, so that the water resistance acts as the remaining load.

[0032] The energy storage peak shaving and valley filling operation mode in step S6 includes the following steps:

[0033] Step S601, putting the energy storage peak shaving and valley filling control pressure plate into operation to execute the energy storage peak shaving and valley filling control strategy.

[0034] Step S602, determine the operation mode of the energy storage bidirectional inverter, if the energy storage bidirectional inverter is in the grid-connected operation state, continue, otherwise start the energy storage bidirectional inverter to run in grid connection.

[0035] Step S603, reading the current planned battery power value.

[0036] Step S604, determine whether the battery SOC is within the allowable range. If the battery SOC is within the allowable range, the planned power output is performed. If the battery SOC is greater than the upper limit and the planned battery power is charging, the battery power is set to 0. If the battery SOC is greater than the upper limit and the planned battery power is discharging, the planned power output is performed. If the battery SOC is less than the lower limit and the planned battery power is discharging, the battery power is set to 0. If the battery SOC is less than the lower limit and the planned battery power is charging, the planned power output is performed.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention can recover the electric energy output during the test of the diesel locomotive, and use the energy recovery system to formulate a corresponding control strategy, which can not only perform real-time load regulation in the factory area, but also use the energy storage system to perform peak-valley economic operation, realize low-price charging during valley hours and high-price discharging during peak hours, and improve the economy of factory electricity use. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of diesel locomotive test system.

[0040] Figure 2 Schematic diagram of a microgrid energy storage system based on energy recovery from a diesel locomotive test bench.

[0041] Figure 3 Schematic diagram of energy storage bidirectional inverter.

[0042] Figure 4 This is a flow chart of the diesel locomotive test mode.

[0043] Figure 5 This is a flow chart of the peak-shaving and valley-filling operation mode of energy storage. DETAILED DESCRIPTION

[0044] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.

[0045] The diesel locomotive test is a necessary step before each diesel locomotive leaves the factory, mainly to verify the performance indicators of the diesel locomotive under different working conditions. During the diesel locomotive test, each test point has requirements for the diesel locomotive speed, output voltage and current, and the operator must adjust the diesel locomotive to run to the test point for relevant performance tests.

[0046] like Figure 1 The figure shows the diesel locomotive test system. The diesel locomotive under test mainly consists of two parts, one is the diesel engine body, and the other is the salient pole synchronous generator pulled by the diesel engine. After the diesel locomotive is started, the internal diesel engine works and drives the AC generator to work. The AC power is converted into DC by the rectifier to provide power output. The diesel locomotive test is a necessary step before each diesel locomotive leaves the factory, mainly to verify the performance indicators of the diesel locomotive under different working conditions. The speed regulation of the diesel locomotive can be achieved by controlling the diesel engine; the output voltage of the diesel locomotive (that is, affecting the output power) can be achieved by adjusting the excitation current of the synchronous generator.

[0047] During the diesel locomotive testing process, each test point has requirements for the diesel locomotive speed, output voltage and current, and the operator must adjust to the test point to conduct relevant performance tests. The lifting and lowering adjustment of the water resistance plate mainly realizes the fine adjustment of the output voltage and current of the diesel locomotive.

[0048] During the operation of the diesel locomotive, the electric energy generated by the synchronous generator is inverted into direct current by the rectifier of the test bench. A large amount of electric energy is generated during the traditional diesel locomotive test. This electric energy is consumed by water resistance heating in the past, resulting in great waste. The water resistance here is equivalent to the test load. By adjusting the lifting position of the water resistance plate and changing the load size, the output voltage and current of the diesel locomotive can be fine-tuned.

[0049] The DC end of the diesel locomotive rectifier outlet is connected in parallel to the DC side of the energy storage PCS (energy storage bidirectional inverter). The energy storage PCS inverts the DC power generated by the diesel locomotive into AC power and connects it to the factory power grid. Adjusting the output power of the energy storage PCS is equivalent to adjusting the water resistance to adjust the test load. Therefore, fine-tuning the output voltage and current of the diesel locomotive can be achieved by adjusting the inverter power of the energy storage PCS. Based on this, we propose a microgrid energy storage system based on energy recovery of the diesel locomotive test bench, such as Figure 2 As shown, it includes an energy recovery microgrid controller, an energy storage bidirectional inverter, a battery subsystem, and a water resistance device. The energy recovery microgrid controller includes a diesel locomotive test mode control unit and an energy storage peak shaving and valley filling operation mode control unit, wherein:

[0050] The diesel locomotive test mode control unit is used to start the energy storage bidirectional inverter to recover electric energy during the diesel locomotive test. At the same time, the size of the in-plant load is judged. When the in-plant load allows, the recovered electric energy is given priority to the in-plant load. When the in-plant load cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy. When neither the in-plant load nor the battery subsystem can absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes it. Energy recovery through diesel locomotive testing can alleviate the pressure of power load in the factory area to a certain extent.

[0051] The energy storage peak-shaving and valley-filling operation mode control unit is used to control the battery subsystem charging at a low electricity price during valley hours and discharging at a high electricity price during peak hours according to the set peak-valley charging and discharging curve when the diesel locomotive is not being tested. Therefore, when the diesel locomotive is not being tested, it can also be charged at a low electricity price during valley hours and discharged at a high electricity price during peak hours according to the set peak-valley charging and discharging curve, thereby improving the economy of factory electricity use.

[0052] The energy recovery microgrid controller is connected to the tachometer, rectifier voltage and current meter and other instruments in the diesel locomotive test system to obtain key signal data during the diesel locomotive test process. Figure 2 As shown, the energy recovery microgrid controller includes an information acquisition unit, which is used to collect load control information, internal combustion engine speed, rectifier outlet voltage, rectifier outlet current, energy storage information, and plant load.

[0053] In another embodiment, the diesel locomotive test mode control unit performs test control by the following formula:

[0054]

[0055] Among them, P PCS Indicates PCS startup mode, P PCS =1 means starting PCS, P PCS=0 means not starting PCS, n means speed, S PCS Indicates PCS status, S PCS =0 means PCS is in shutdown state, S PCS =1 indicates PCS working state; H indicates operation mode, H=1,2,3,4,5,6, H=1 indicates operation mode 1, operation mode 1 is P E =P DC , P W →0; H=2 indicates operation mode 2, which is P E =0; H=3 indicates operation mode 3, which is P E =P DC , P B =-(P DC -P Load ),P W →0; H=4 indicates operation mode 4, which is P E =P DC , P B =0,P W →0; H=5 means operation mode 2, operation mode 5 is P E =P Load -P B,1 , P B =0,P W =P DC -P E ; H = 6 means operation mode 6, operation mode 6 is P E =P DC , P B =0,P W →0;P E represents the target power of the diesel locomotive branch of the energy storage bidirectional inverter, P DC Indicates the output power of the internal combustion engine, P W Indicates the power of the water blocking device, → indicates the tendency, P B represents the target power of the battery branch of the energy storage bidirectional inverter, SOC represents the battery power percentage, P Load Indicates load power, P B,1 Indicates the current power of the battery branch of the energy storage bidirectional inverter, P E,1 Indicates the current power of the diesel locomotive branch of the energy storage bidirectional inverter.

[0056] The diesel locomotive test mode control unit is used to detect whether the speed of the diesel locomotive is greater than 0 and judge that the energy storage bidirectional inverter is in a shutdown state according to the energy storage information, then the network starts the energy storage bidirectional inverter and sets the initial power of the energy storage bidirectional inverter to 0. According to the rectifier outlet voltage and the rectifier outlet current, it is detected whether the diesel locomotive generates output power. If the diesel locomotive has generated output power, the target power of the diesel locomotive branch of the energy storage bidirectional inverter is adjusted to be equal to the output power of the diesel locomotive, and the water resistance device is gradually withdrawn. According to the energy storage information, the SOC range of the energy storage battery is judged. If the battery SOC is less than 80%, it is continued to judge whether the current diesel locomotive power is greater than the current plant load. If it is greater, the energy storage bidirectional inverter battery branch is set to charge the battery, and the charging power is the diesel locomotive power-the current plant load, otherwise the energy storage bidirectional inverter battery branch is set to 0 to stop charging. If the battery SOC is greater than 80%, the power of the energy storage bidirectional inverter battery branch is set to 0 to stop charging. If the discharge power of the energy storage bidirectional inverter diesel locomotive branch to the grid is greater than the current plant load at this time, the current energy storage bidirectional inverter diesel locomotive branch target value is limited to the load value, and the water resistance plate is lowered at the same time, and the water resistance acts as the remaining load.

[0057] The energy storage peak shaving and valley filling operation mode control unit first determines the operation mode of the energy storage bidirectional inverter. If the energy storage bidirectional inverter is in the grid-connected operation state, it continues; otherwise, it starts the energy storage bidirectional inverter to be grid-connected. Read the current battery planned power value. Determine whether the battery SOC is within the allowable range. If the battery SOC is within the allowable range, the planned power output is performed. If the battery SOC is greater than the upper limit value and the battery planned power is charging, the battery power is set to 0. If the battery SOC is greater than the upper limit value and the battery planned power is discharging, the planned power output is performed. If the battery SOC is less than the lower limit value and the battery planned power is discharging, the battery power is set to 0. If the battery SOC is less than the lower limit value and the battery planned power is charging, the planned power output is performed.

[0058] Therefore, the energy recovery microgrid controller can respond to the load control command of the diesel locomotive test control system, execute the corresponding control strategy, adjust the charging and discharging power of the water resistance plate and the energy storage PCS, and control the lifting and lowering of the water resistance plate. It is connected to the energy storage PCS and battery system, monitors and controls the operation of the energy storage PCS, and monitors the battery voltage, SOC and other information.

[0059] like Figure 3As shown, the energy storage PCS stands for energy storage bidirectional inverter, which is used to convert stored DC power (such as obtained from batteries or other energy storage devices) into AC power. The energy storage bidirectional inverter is provided with multiple battery control modules, each of which independently controls the battery group, so it can be modularized with multi-branch design, and each module independently controls the battery group access. In addition, the energy storage bidirectional inverter of this embodiment is used to invert the DC power output during the diesel locomotive test into AC power to supply power to the plant load or charge the battery.

[0060] The PCS controller communicates with the BMS through the CAN interface to obtain battery pack status information, which can realize protective charging and discharging of the battery to ensure safe battery operation.

[0061] The power of the battery branch of the energy storage bidirectional inverter and the internal combustion engine branch of the energy storage bidirectional inverter should be greater than 1.2 times the maximum power of the diesel locomotive test to meet the energy recovery requirements of the diesel locomotive test bench.

[0062] The main function of the battery subsystem is to store electricity and charge and discharge in coordination with the control strategy. The battery subsystem includes a battery pack and a battery management module BMS. The battery management system is the intelligent control center of the battery energy storage system. The battery management module BMS is used to monitor and manage the status and performance of the battery pack. It includes functions such as battery status monitoring, temperature control, battery balancing, and fault diagnosis to ensure the safety, stability, and long life of the battery pack.

[0063] According to the standards of the International Electrotechnical Commission (IEC), the capacity of the energy storage inverter battery should be determined based on the ratio of the rated power of the energy storage inverter and the maximum output power of the battery. In general, the battery capacity should be 2-4 times the rated power of the energy storage inverter.

[0064] In another embodiment, a method for energy recovery of a microgrid energy storage system based on energy recovery of a diesel locomotive test bench is provided, and the method adopts the microgrid energy storage system based on energy recovery of a diesel locomotive test bench, and comprises the following steps:

[0065] Step S1, the diesel locomotive is installed on the test bench, and the starter motor is physically connected to the diesel locomotive drive shaft. The AC output end of the diesel locomotive synchronous generator is connected to the AC input end of the rectifier. The DC output end of the rectifier is connected to the positive and negative plates of the water resistance device.

[0066] Step S2, the rectifier outlet is connected to the DC branch of the energy storage bidirectional inverter. The battery subsystem is connected to another DC branch of the energy storage bidirectional inverter. The AC end of the energy storage bidirectional inverter is connected to the large power grid of the factory area.

[0067] The battery branch power of the energy storage bidirectional inverter and the internal combustion engine branch power of the energy storage bidirectional inverter should be 1.2 times greater than the full power of the internal combustion locomotive; the battery capacity should be 2-4 times the rated power of the battery branch of the energy storage inverter.

[0068] In step S3, the energy recovery microgrid controller communicates with the test bench tachometer, DC voltmeter, DC ammeter and other electronic instruments through the secondary communication cable to collect signals such as speed, rectifier outlet voltage, and rectifier current. The energy recovery microgrid controller controls the lifting of the water resistance plate through the secondary cable. The energy recovery microgrid controller collects and controls the operation of the energy storage bidirectional inverter equipment through the GOOSE communication network. CT and PT mutual inductors are installed at the plant load to collect plant load information and send it to the energy recovery microgrid controller.

[0069] Step S4, during the diesel locomotive test, the diesel engine speed, generator excitation current, and system load are controlled by the test console to adjust the output voltage and current to meet the test point requirements. The system load includes water resistance and energy storage bidirectional inverter. The specific load proportion distribution is determined by the control method of the energy recovery microgrid controller. The control method of the energy recovery microgrid controller includes the diesel locomotive test mode and the energy storage peak shaving and valley filling operation mode.

[0070] Step S5, the diesel locomotive test mode is: when the diesel locomotive is tested, the energy storage bidirectional inverter is started to recover electric energy. At the same time, the size of the load in the factory is judged. If the load in the factory allows, the recovered electric energy is used by the load in the factory first. When the load in the factory cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy. When neither the load in the factory nor the battery subsystem can absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes it.

[0071] like Figure 4 As shown, the diesel locomotive test mode is tested and controlled by the following formula:

[0072]

[0073] P PCS Indicates PCS startup mode, P PCS =1 means starting PCS, P PCS =0 means not starting PCS, n means speed, S PCS Indicates PCS status, S PCS =0 means PCS is in shutdown state, S PCS =1 indicates that it is in PCS working state.

[0074]

[0075] Among them, H represents the operation mode, H=1,2,3,4,5,6, H=1 represents operation mode 1, operation mode 1 is P E =P DC , P W →0; H=2 indicates operation mode 2, which is P E =0; H=3 indicates operation mode 3, which is P E =P DC , P B =-(P DC -P Load ),P W →0; H=4 indicates operation mode 4, which is P E =P DC , P B =0,P W →0; H=5 means operation mode 2, operation mode 5 is P E =P Load -P B,1 , P B =0,P W =P DC -P E ; H = 6 means operation mode 6, operation mode 6 is P E =P DC , P B =0,P W →0;P E represents the target power of the diesel locomotive branch of the energy storage bidirectional inverter, P DC Indicates the output power of the internal combustion engine, P W Indicates the power of the water blocking device, → indicates the tendency, P B represents the target power of the battery branch of the energy storage bidirectional inverter, SOC represents the battery power percentage, P Load Indicates load power, P B,1 Indicates the current power of the battery branch of the energy storage bidirectional inverter, P E,1 Indicates the current power of the diesel locomotive branch of the energy storage bidirectional inverter.

[0076] The specific steps include:

[0077] Step S501, detect whether there is a diesel locomotive platform in use, and if so, detect the relevant information of the corresponding platform.

[0078] Step S502, detect that the speed of the internal combustion engine locomotive n>0 and the energy storage bidirectional inverter is in a shutdown state. If the condition is met, the energy storage bidirectional inverter is connected to the grid and the initial power P of the internal combustion engine branch of the energy storage bidirectional inverter is set. E =0.

[0079] Step S503: according to the internal combustion engine output power PDC >0 determines whether the diesel locomotive generates output power. If the diesel locomotive has generated output power, adjust the target power P of the diesel locomotive branch of the energy storage bidirectional inverter E Equal to the output power P of the diesel locomotive DC , that is, P E =P DC , and gradually withdraw the water resistance device.

[0080] Step S504, determine the SOC range of the energy storage battery according to the energy storage information. If the battery SOC is less than 80%, continue to determine the current locomotive power P DC Is it greater than the current plant load P Load , if P DC >P Load , then set up a bidirectional inverter battery branch to charge the battery (specify P B Positive discharge, negative charge), the calculation formula is: P B =-(P DC -P Load ), otherwise the energy storage bidirectional inverter battery branch P B =0 to stop charging. If the battery SOC is greater than 80%, set the energy storage bidirectional inverter battery branch power P B =0 to stop charging. If the battery charging power |P B |>P Load , then limit the current energy storage bidirectional inverter diesel locomotive branch P E The target value is set to the load value, and the water resistance plate is lowered to act as the remaining load. The battery branch power P of the energy storage bidirectional inverter B The calculation formula is: B =-P Load .

[0081] Step S505, when the above strategy is executed, in order to avoid sudden increase or decrease of the power of the energy storage bidirectional inverter affecting the internal combustion engine test, the target power should be increased or decreased according to the set step size (such as increase or decrease in steps of 10kW) after the target power is calculated.

[0082] Step S6, the energy storage peak shaving and valley filling operation mode is: when the diesel locomotive is not tested, according to the set peak-valley charge and discharge curve, the battery subsystem is controlled to charge at a low electricity price during valley hours and to discharge at a high electricity price during peak hours.

[0083] like Figure 5 As shown in FIG. 1 , the energy storage peak shaving and valley filling operation mode specifically includes the following steps:

[0084] Step S601, putting the energy storage peak shaving and valley filling control pressure plate into operation to execute the energy storage peak shaving and valley filling control strategy.

[0085] Step S602, determine the operation mode of the energy storage bidirectional inverter, if the energy storage bidirectional inverter is in the grid-connected operation state, continue, otherwise start the energy storage bidirectional inverter to run in grid connection.

[0086] Step S603, reading the current planned battery power value.

[0087] Step S604, determine whether the battery SOC is within the allowable range. If the battery SOC is within the allowable range, then the planned power output is performed. If the battery SOC is greater than the upper limit and the battery planned power is charging, then set the battery branch power P B =0. If the battery SOC is greater than the upper limit and the battery planned power is discharge, then the planned power output is used. If the battery SOC is less than the lower limit and the battery planned power is discharge, then the battery branch power P is set. B = 0. If the battery SOC is less than the lower limit and the battery planned power is charging, the planned power output is followed.

[0088] The microgrid energy storage system based on energy recovery of the diesel locomotive test bench of the present invention is connected to a microgrid energy storage system on the basis of the traditional diesel locomotive test platform, and cooperates with the energy recovery microgrid control strategy to recover the electric energy generated during the diesel locomotive test, and reasonably distributes it to the plant load and energy storage battery system. The energy recovery microgrid controller communicates with the test bench tachometer, DC voltmeter, DC ammeter and other electronic instruments through the secondary communication cable to collect signals such as speed, rectifier outlet voltage, current, etc.; the energy recovery microgrid controller controls the lifting of the water resistance plate through the secondary cable; the energy recovery microgrid controller collects and controls the operation of the energy storage PCS equipment through the GOOSE communication network; CT and PT mutual inductors are installed at the plant load to collect the plant load information and send it to the energy recovery microgrid controller. The energy recovery control system is divided into two sets of control strategies. The first set is the energy engine test mode, which recovers the electric energy generated by the diesel locomotive test and reasonably distributes it to the plant load and energy storage system for use; the second set is the energy storage peak shaving and valley filling operation mode, which runs in the energy recovery idle time period and uses the energy storage system for peak and valley economic operation.

[0089] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A microgrid energy storage system based on energy recovery of a diesel locomotive test bench, characterized by: It includes an energy recovery microgrid controller, an energy storage bidirectional inverter, a battery subsystem, and a water resistance device. The energy recovery microgrid controller includes a diesel locomotive test mode control unit and an energy storage peak shaving and valley filling operation mode control unit, wherein: The diesel locomotive test mode control unit is used to start the energy storage bidirectional inverter to recover electric energy when the diesel locomotive is tested; at the same time, the size of the load in the factory is judged, and when the load in the factory allows, the recovered electric energy is used by the load in the factory first; when the load in the factory cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy; when the load in the factory and the battery subsystem cannot absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes the electric energy; The energy storage peak shaving and valley filling operation mode control unit is used to control the charging of the battery subsystem at a low electricity price during valley hours and the discharging of the battery subsystem at a high electricity price during peak hours according to the set peak-valley charging and discharging curve when the diesel locomotive is not being tested.

2. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 1 is characterized in that: The diesel locomotive test mode control unit performs test control by the following formula: Among them, P PCS Indicates PCS startup mode, P PCS =1 means starting PCS, P PCS =0 means not starting PCS, n means speed, S PCS Indicates PCS status, S PCS =0 means PCS is in shutdown state, S PCS =1 indicates PCS working state; H indicates operation mode, H=1,2,3,4,5,6, H=1 indicates operation mode 1, operation mode 1 is P E =P DC , P W →0; H=2 indicates operation mode 2, which is P E =0; H=3 indicates operation mode 3, which is P E =P DC , P B =-(P DC -P Load ),P W →0; H=4 indicates operation mode 4, which is P E =P DC , P B =0,P W →0; H=5 means operation mode 2, operation mode 5 is P E =P Load -P B,1 , P B =0,P W =P DC -P E ; H = 6 means operation mode 6, operation mode 6 is P E =P DC , P B =0,P W →0;P E represents the target power of the diesel locomotive branch of the energy storage bidirectional inverter, P DC Indicates the output power of the internal combustion engine, P W Indicates the power of the water blocking device, → indicates the tendency, P B represents the target power of the battery branch of the energy storage bidirectional inverter, SOC represents the battery power percentage, P Load Indicates load power, P B,1 Indicates the current power of the battery branch of the energy storage bidirectional inverter, P E,1 Indicates the current power of the diesel locomotive branch of the energy storage bidirectional inverter.

3. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 2 is characterized in that: The energy recovery microgrid controller includes an information collection unit, which is used to collect load control information, internal combustion engine speed, rectifier outlet voltage, rectifier outlet current, energy storage information, and plant load; the internal combustion engine test mode control unit is used to detect whether the internal combustion engine speed is greater than 0 and judge that the energy storage bidirectional inverter is in a shutdown state according to the energy storage information, then the network starts the energy storage bidirectional inverter and sets the initial power of the energy storage bidirectional inverter to 0; detect whether the internal combustion engine generates output power according to the rectifier outlet voltage and rectifier outlet current, if the internal combustion engine has generated output power, then adjust the target power of the internal combustion engine branch of the energy storage bidirectional inverter to be equal to the output power of the internal combustion engine, and gradually exit the water Resistance device; determine the SOC range of the energy storage battery according to the energy storage information. If the battery SOC is less than 80%, continue to determine whether the current diesel locomotive power is greater than the current plant load. If it is greater, set the energy storage bidirectional inverter battery branch to charge the battery, and the charging power is the diesel locomotive power-the current plant load. Otherwise, the energy storage bidirectional inverter battery branch is set to 0 to stop charging; if the battery SOC is greater than 80%, set the energy storage bidirectional inverter battery branch power to 0 to stop charging. If the discharge power of the energy storage bidirectional inverter diesel locomotive branch to the grid is greater than the current plant load at this time, limit the current energy storage bidirectional inverter diesel locomotive branch target value to the load value, and at the same time lower the water resistance plate, and the water resistance acts as the remaining load.

4. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 3 is characterized in that: The energy storage peak shaving and valley filling operation mode control unit first determines the operation mode of the energy storage bidirectional inverter. If the energy storage bidirectional inverter is in the grid-connected operation state, it continues; otherwise, it starts the energy storage bidirectional inverter to be grid-connected and operated; reads the current battery planned power value; determines whether the battery SOC is in the allowable range. If the battery SOC is in the allowable range, it outputs power according to the plan; if the battery SOC is greater than the upper limit value and the battery planned power is charging, the battery power is set to 0; if the battery SOC is greater than the upper limit value and the battery planned power is discharging, the planned power is output; if the battery SOC is less than the lower limit value and the battery planned power is discharging, the battery power is set to 0; if the battery SOC is less than the lower limit value and the battery planned power is charging, the planned power is output.

5. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 4 is characterized in that: The energy storage bidirectional inverter is used to convert the stored direct current into alternating current.

6. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 5 is characterized in that: The energy storage bidirectional inverter is provided with a plurality of battery control modules, and each battery control module independently controls a battery pack.

7. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 6 is characterized in that: The battery subsystem includes a battery pack and a battery management module BMS. The battery management module BMS is used to monitor and manage the status and performance of the battery pack.

8. The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to claim 7 is characterized in that: The battery branch power of the energy storage bidirectional inverter and the internal combustion engine branch power should be 1.2 times greater than the full power of the internal combustion locomotive; the battery capacity should be 2-4 times the rated power of the battery branch of the energy storage inverter.

9. An energy recovery method for a microgrid energy storage system based on energy recovery of a diesel locomotive test bench, characterized in that: The microgrid energy storage system based on energy recovery of a diesel locomotive test bench according to any one of claims 1 to 8 comprises the following steps: Step S1, the diesel locomotive is installed on the test bench, the starter motor is physically connected to the diesel locomotive drive shaft; the AC output end of the diesel locomotive synchronous generator is connected to the AC input end of the rectifier; the DC output end of the rectifier is connected to the positive and negative plates of the water resistance device; Step S2, the rectifier outlet is connected to the DC branch of the energy storage bidirectional inverter; the battery subsystem is connected to another DC branch of the energy storage bidirectional inverter; the AC end of the energy storage bidirectional inverter is connected to the large power grid of the factory area; Step S3, the energy recovery microgrid controller communicates with the test bench tachometer, DC voltmeter, and DC ammeter through the secondary communication cable to collect the speed, rectifier outlet voltage, and rectifier current; the energy recovery microgrid controller controls the lifting of the water resistance plate through the secondary cable; the energy recovery microgrid controller collects and controls the operation of the energy storage bidirectional inverter equipment through the GOOSE communication network; CT and PT mutual inductors are installed at the plant load to collect the plant load information and send it to the energy recovery microgrid controller; Step S4, during the diesel locomotive test, the diesel engine speed, the generator excitation current, and the system load are controlled by the test console to adjust the output voltage and current to meet the test point requirements; the system load includes a water resistance and an energy storage bidirectional inverter, and the specific load proportion distribution is determined by the control method of the energy recovery microgrid controller, and the control method of the energy recovery microgrid controller includes a diesel locomotive test mode and an energy storage peak shaving and valley filling operation mode; Step S5, the diesel locomotive test mode is: when the diesel locomotive is tested, the energy storage bidirectional inverter is started to recover electric energy; at the same time, the size of the load in the factory is judged, and when the load in the factory allows, the recovered electric energy is used by the load in the factory first; when the load in the factory cannot completely absorb the recovered electric energy, the energy storage bidirectional inverter is controlled to charge the battery in the battery subsystem to absorb excess electric energy; when the load in the factory and the battery subsystem cannot absorb the recovered electric energy, the water resistance device is controlled to adjust the water resistance plate, and the water resistance consumes the electric energy; Step S6, the energy storage peak shaving and valley filling operation mode is: when the diesel locomotive is not tested, according to the set peak-valley charge and discharge curve, the battery subsystem is controlled to charge at a low electricity price during valley hours and to discharge at a high electricity price during peak hours.

10. The energy recovery method of the microgrid energy storage system based on the energy recovery of the diesel locomotive test bench according to claim 9 is characterized in that: The diesel locomotive test mode in step S5 includes the following steps: Step S501, detecting whether there is a diesel locomotive platform in use, and if so, detecting relevant information of the corresponding platform; Step S502, detecting whether the speed of the diesel locomotive is greater than 0 and the energy storage bidirectional inverter is in a shutdown state, if the conditions are met, starting the energy storage bidirectional inverter and setting the initial power of the energy storage bidirectional inverter to 0; Step S503, detecting whether the diesel locomotive generates output power according to the rectifier outlet voltage and the rectifier outlet current, if the diesel locomotive has generated output power, adjusting the target power of the diesel locomotive branch of the energy storage bidirectional inverter to be equal to the output power of the diesel locomotive, and gradually exiting the water resistance device; Step S504, judging the SOC range of the energy storage battery according to the energy storage information, if the battery SOC is less than 80%, continue to judge whether the current diesel locomotive power is greater than the current plant load, if greater, set the energy storage bidirectional inverter battery branch to charge the battery, the charging power is the diesel locomotive power minus the current plant load, otherwise the energy storage bidirectional inverter battery branch is set to 0 to stop charging; if the battery SOC is greater than 80%, set the energy storage bidirectional inverter battery branch power to 0 to stop charging, if at this time the energy storage bidirectional inverter diesel locomotive branch discharge power to the grid is greater than the current plant load, then limit the current energy storage bidirectional inverter diesel locomotive branch target value to the load value, and at the same time lower the water resistance plate, and let the water resistance act as the remaining load; The energy storage peak shaving and valley filling operation mode in step S6 includes the following steps: Step S601, putting the energy storage peak shaving and valley filling control pressure plate into operation to execute the energy storage peak shaving and valley filling control strategy; Step S602, determining the operation mode of the energy storage bidirectional inverter, if the energy storage bidirectional inverter is in a grid-connected operation state, then continue, otherwise start the energy storage bidirectional inverter to be grid-connected; Step S603, reading the current battery planned power value; Step S604, determine whether the battery SOC is within the allowable range. If the battery SOC is within the allowable range, the planned power output is performed; if the battery SOC is greater than the upper limit value and the planned battery power is charging, the battery power is set to 0; if the battery SOC is greater than the upper limit value and the planned battery power is discharging, the planned power output is performed; if the battery SOC is less than the lower limit value and the planned battery power is discharging, the battery power is set to 0; if the battery SOC is less than the lower limit value and the planned battery power is charging, the planned power output is performed.

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