Energy storage type charging device

Abstract

The invention discloses an energy storage type charging device, and relates to the technical field of coal mine electromechanical equipment. The energy storage type charging device comprises an energy storage device, a charging circuit and a charging controller. The input end of the charging circuit is connected with the energy storage device, and the output end of the charging circuit is used for being connected to external equipment to be charged; when the charging circuit is connected to the to-be-charged equipment, the charging circuit is used for obtaining electric energy from the energy storage device and charging the to-be-charged equipment; the charging controller is electrically connected with the charging circuit and used for collecting the charging voltage and the charging current output by the charging circuit in real time and adjusting the voltage output value of the charging circuit through a voltage and current double-loop control algorithm based on the collected charging voltage and the charging current so that the voltage value of the charging voltage can be stabilized at a preset charging voltage value. According to the technical scheme, the working efficiency of the underground electric vehicle can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of coal mine electromechanical equipment technology, and in particular to an energy storage charging device. Background Technology

[0002] Coal, as a crucial basic energy source in my country, is mined on a massive scale, and mine tunnels have complex structures. Currently, underground transportation relies primarily on auxiliary transport equipment such as explosion-proof diesel trackless rubber-tired vehicles and fuel-powered monorail cranes. However, these fuel-powered vehicles suffer from high emissions, high energy consumption, and high noise levels, severely impacting mine ventilation and the occupational health of workers. In recent years, with the development of new energy technologies, electric trackless rubber-tired vehicles and electric monorail cranes based on lithium-ion batteries have been gradually applied to and widely promoted in coal mine auxiliary transportation. These electric vehicles effectively alleviate underground air pollution, offer significant energy-saving and consumption-reducing advantages, and simultaneously improve the automation and intelligence level of coal mine auxiliary transportation.

[0003] Currently, the main applications of electric vehicles in coal mines are concentrated on personnel transportation and small-tonnage material transportation, with their usage rate continuously increasing, making them an important form of auxiliary transportation in coal mines. Considering the special requirements of coal mine safety regulations, existing electric vehicles generally adopt a "ground charging, underground operation" working mode, returning to the surface to recharge after completing underground transportation tasks.

[0004] However, due to the limited battery capacity of electric trackless rubber-tired vehicles and electric monorail cranes, they often need to be recharged midway during continuous underground operation. Current recharging methods usually require the vehicles to be raised to the surface for charging, resulting in the vehicles spending a lot of time traveling between the underground and the surface, which not only reduces transportation efficiency but also seriously affects the utilization rate of underground electric vehicles. Summary of the Invention

[0005] In view of this, this application provides an energy storage charging device, the main purpose of which is to solve the technical problem of low working efficiency caused by the need for underground electric vehicles to travel to and from the ground to replenish energy.

[0006] According to a first aspect of the present invention, an energy storage charging device is provided, the energy storage charging device comprising an energy storage device, a charging circuit, and a charging controller;

[0007] The input terminal of the charging circuit is connected to the energy storage device, and the output terminal of the charging circuit is used to connect to an external device to be charged.

[0008] When the charging circuit is connected to the device to be charged, the charging circuit is used to obtain electrical energy from the energy storage device and charge the device to be charged;

[0009] The charging controller is electrically connected to the charging circuit and is used to collect the charging voltage and charging current output by the charging circuit to the device to be charged in real time. Based on the collected charging voltage and charging current, the controller adjusts the voltage output value of the charging circuit through a voltage and current dual-loop control algorithm to stabilize the charging voltage value at a preset charging voltage value.

[0010] Optionally, the charging circuit includes a DC input circuit, a DC output circuit, and multiple chopper circuits; the positive input terminal of the DC input circuit is connected to the positive terminal of the energy storage device, the positive output terminal of the DC input circuit is connected to the positive input terminal of each chopper circuit, the negative input terminal of the DC input circuit is connected to the negative terminal of the energy storage device, and the negative output terminal of the DC input circuit is connected to the negative input terminal of each chopper circuit; the connection terminal of the DC output terminals of each chopper circuit is connected to the positive input terminal of the DC output circuit, and the negative input terminal of the DC output circuit is connected to the negative input terminal of each chopper circuit; the positive output terminal of the DC output circuit is used to connect to the positive terminal of the device to be charged to output the charging current and the charging voltage to the device to be charged; the negative output terminal of the DC output circuit is used to connect to the negative terminal of the device to be charged; the control terminal of the bridge arm switch in the chopper circuit is connected to the control terminal of the charging controller, and the charging controller is used to control the bridge arm switch to be in an on / off state.

[0011] Optionally, the charging controller, based on the acquired charging voltage and charging current, adjusts the voltage output value of the charging circuit using a voltage-current dual-loop control algorithm to stabilize the charging voltage value at a preset charging voltage value. This includes: the charging controller comparing the preset charging voltage value with the acquired charging voltage to obtain a voltage error signal; performing outer-loop voltage proportional-integral (PI) regulation on the voltage error signal to generate a current setpoint; performing amplitude limiting on the current setpoint to obtain a current target value for inner-loop current control; comparing the current target value with the charging current to obtain a current difference; performing inner-loop current PI regulation on the current difference to obtain a duty cycle target value; and generating multiple back-end pulse width modulation (PWM) signals based on the duty cycle target value, wherein the phase difference between each PWM signal is 120 degrees; and sending the multiple PWM signals to the control terminals of different bridge arm switches within the chopper circuit to stabilize the charging voltage value at the preset charging voltage value.

[0012] Optionally, the energy storage charging device further includes a power access circuit; the discharge terminal of the power access circuit is connected to the energy storage device, and the charging terminal of the power access circuit is used to connect to an external power source. When connected to the external power source, the power access circuit is used to access charging power from the external power source and charge the energy storage device based on the charging power. The charging controller is electrically connected to the power access circuit, and the charging controller is also used to collect the output current and output voltage of the power access circuit charging the energy storage device in real time, and based on the collected output current and output voltage, adjust the current output value of the power access circuit through a voltage and current dual-loop control algorithm to stabilize the output current value at a preset output current value.

[0013] Optionally, the power access circuit includes an AC access circuit, a rectifier circuit, an H-bridge inverter circuit, and a DC output circuit; the AC access circuit is used to access an external power source to receive AC power from the external power source and to deliver the AC power to the rectifier circuit; the rectifier circuit is used to convert the AC power into DC power and to send the DC power to the H-bridge inverter circuit; the H-bridge inverter circuit is used, under the control of the charging controller, to invert the DC power into AC power and to output the AC power to the DC output circuit; the DC output circuit is used to rectify the AC current to obtain an output current and to charge the energy storage device based on the output current.

[0014] Optionally, the H-bridge inverter circuit includes a first bridge arm and a second bridge arm, the first bridge arm including a first upper bridge arm and a first lower bridge arm, and the second bridge arm including a second upper bridge arm and a second lower bridge arm; the charging controller controls the H-bridge inverter circuit to convert the DC power to AC power, including: the charging controller compares a preset output current value with a sampled output current to obtain a current error signal, and performs outer loop current proportional-integral regulation on the current error signal to generate a voltage setpoint; determines the difference between the voltage setpoint and the sampled output voltage, and performs inner loop voltage proportional-integral regulation on the difference between the voltage setpoint and the sampled output voltage. The target phase shift angle is obtained; a first front-end pulse width modulation signal and a second front-end pulse width modulation signal are generated based on the target phase shift angle, wherein the first front-end pulse width modulation signal and the second front-end pulse width modulation signal have the same duty cycle and a phase difference of 180 degrees; the first front-end pulse width modulation signal is used to control the conduction and disconnection of the first upper bridge arm and the second lower bridge arm, and the second front-end pulse width modulation signal is used to control the conduction and disconnection of the second upper bridge arm and the first lower bridge arm, so that the H-bridge inverter circuit outputs an AC current of a preset output current value.

[0015] Optionally, the charging controller is further configured to compare the charging voltage value with a preset voltage alarm threshold, and when the charging voltage value exceeds the voltage alarm threshold, control the bridge arm switch in each chopper circuit to be in an open state to stop the charging operation of the device to be charged; the charging controller is further configured to compare the charging current value with a preset current alarm threshold, and when the charging current value exceeds the current alarm threshold, control the bridge arm switch in each chopper circuit to be in an open state to stop the charging operation of the device to be charged.

[0016] Optionally, the charging controller is also used to collect the temperature value of the charging circuit and compare the temperature value with a preset temperature alarm threshold. When the temperature value exceeds the temperature alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in the open state to stop the charging operation of the device to be charged.

[0017] Optionally, the bridge arm switch is an insulated gate bipolar transistor; the charging controller is also used to collect the voltage drop value of each insulated gate bipolar transistor, compare the voltage drop value with a preset voltage drop threshold, and when the voltage drop value exceeds the voltage drop threshold, control the bridge arm switch in each chopper circuit to be in the open state to stop the charging operation of the device to be charged.

[0018] Optionally, the charging controller establishes a communication connection with a remote host computer via Ethernet communication, bus communication, and serial communication.

[0019] This invention provides an energy storage charging device that effectively solves the technical problem of low working efficiency of underground electric vehicles. By integrating an energy storage device, a charging circuit, and a charging controller, this device enables efficient power replenishment for equipment such as electric trackless rubber-tired vehicles and electric monorail cranes in underground environments, significantly improving the utilization rate and transportation efficiency of underground electric vehicles. Specifically, by setting up an energy storage charging device underground, after fully charging the energy storage device, it can be placed underground to charge equipment in environments without power supply. Electric vehicles can travel underground to the energy storage charging device to charge using the stored energy, thus eliminating the need for frequent venturing to the surface for charging and reducing the time spent traveling between underground and the surface, thereby greatly improving the working utilization rate of underground electric vehicles.

[0020] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0022] Figure 1 This diagram illustrates the structure of an energy storage charging device according to an embodiment of the present invention.

[0023] Figure 2 A schematic diagram of a charging circuit provided in an embodiment of the present invention is shown;

[0024] Figure 3 A schematic diagram of a chopper circuit provided in an embodiment of the present invention is shown;

[0025] Figure 4 This diagram illustrates a process for adjusting the voltage output value of a charging circuit using a dual-loop voltage and current control algorithm, as provided in an embodiment of the present invention.

[0026] Figure 5 This invention provides a schematic diagram of the structure of another energy storage charging device according to an embodiment of the invention.

[0027] Figure 6 This diagram illustrates the structure of a power access circuit according to an embodiment of the present invention.

[0028] Figure 7 A schematic diagram of a rectifier unit provided in an embodiment of the present invention is shown;

[0029] Figure 8 This diagram illustrates the structure of a switching transistor according to an embodiment of the present invention.

[0030] Figure 9 This diagram illustrates a process for adjusting the current output value of an energy access circuit based on a voltage-current dual-loop control algorithm, according to an embodiment of the present invention.

[0031] Figure 10 A schematic diagram of a charging controller provided in an embodiment of the present invention is shown. Detailed Implementation

[0032] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the present application can be combined with each other.

[0033] Currently, the main applications of electric vehicles in coal mines are concentrated on personnel transportation and small-tonnage material transportation, with their usage rate continuously increasing, making them an important form of auxiliary transportation in coal mines. Considering the special requirements of coal mine safety regulations, existing electric vehicles generally adopt a "ground charging, underground operation" working mode, returning to the surface for recharging after completing underground transportation tasks. However, due to the limited battery capacity of electric trackless rubber-tired vehicles and electric monorail cranes, recharging is often required during continuous underground operation. Current recharging methods typically require the vehicle to be brought to the surface for charging, resulting in a significant amount of time spent traveling between underground and the surface, which not only reduces transportation efficiency but also seriously affects the utilization rate of underground electric vehicles.

[0034] To address the above problems, in one embodiment, such as Figure 1 As shown, an energy storage charging device is provided. Taking its application in an underground coal mine as an example, the energy storage charging device includes an energy storage device 100, a charging circuit 200, and a charging controller (not shown in the figure). Here, the energy storage charging device can be installed on a mobile vehicle 10, which can be an electric vehicle or a non-powered trolley. Here, the electric vehicle can have autonomous driving capabilities to travel underground.

[0035] Furthermore, the energy storage device 100 can be a lithium iron phosphate battery pack or other energy storage equipment with a rated voltage of DC 610V and a rated total capacity of 230Ah*2 = 460Ah, storing approximately 270kWh (kilowatt-hours). Furthermore, in accordance with coal mine safety regulations, each 230Ah represents a power battery unit, and the energy storage device 100 is designed with two sets of battery units connected in parallel. Furthermore, the charging controller can be a digital signal processor or a microcontroller, or other computer equipment.

[0036] Furthermore, the charging controller can have an Ethernet interface, a bus interface, and a serial communication interface. The charging controller can connect to a remote host computer via the Ethernet interface using an Ethernet cable, via the bus interface using a Controller Area Network (CAN) bus, or via the serial communication interface using an RS485 bus, thus establishing a communication connection with the host computer through Ethernet, bus, and serial communication. The host computer can be a control terminal or server in the coal mine's control center.

[0037] Furthermore, the input terminal of the charging circuit 200 is connected to the energy storage device 100, and the output terminal of the charging circuit 200 is used to connect to an external device 20 to be charged; wherein, the device 20 to be charged can be a battery mounted on an electric vehicle such as an electric trackless rubber-wheeled vehicle or an electric monorail crane.

[0038] Furthermore, when the charging circuit 200 is connected to the device to be charged 20, the charging circuit 200 is used to obtain electrical energy from the energy storage device 100 and charge the device to be charged 20. In actual operation, the energy storage charging device can be moved to the device to be charged 20 underground by the power of the mobile vehicle 10, and the battery of the device to be charged 20 is connected to the charging circuit 200 to charge the device to be charged 20.

[0039] Furthermore, the charging controller is electrically connected to the charging circuit 200 and is used to collect the charging voltage and charging current output by the charging circuit 200 when charging the device 20 to be charged in real time. Based on the collected charging voltage and charging current, the controller adjusts the voltage output value of the charging circuit through a voltage and current dual-loop control algorithm to stabilize the charging voltage value at a preset charging voltage value.

[0040] Specifically, when the device 20 to be charged is connected to the charging circuit 200 manually or automatically, the charging circuit 200 draws electrical energy from the energy storage device 100 and charges the device 20 based on this electrical energy. During the charging process, the charging controller can receive a preset charging voltage value from the host computer, which is the target voltage value for charging the device 20, and collects the charging voltage and charging current output by the charging circuit 200 to the device 20 in real time. It then adjusts the voltage output value of the charging circuit 200 through a voltage-current dual-loop control algorithm to stabilize the charging voltage value output by the charging circuit 200 to the device 20 at the preset charging voltage value.

[0041] The voltage-current dual-loop control algorithm is a closed-loop regulation mechanism commonly used in power management and charging control. It achieves high-precision and stable control of the output voltage through the synergistic effect of the outer voltage loop and the inner current loop. Specifically, the charging controller first compares the preset charging voltage value with the actual collected charging voltage value to obtain a voltage error signal. Then, the required current setpoint is calculated by the outer voltage controller (such as a PI controller). Subsequently, this current setpoint is compared with the actual charging current of the charging voltage 200. After adjustment by the inner current controller, a pulse width modulation (PWM) signal is generated to control the conduction state of the power devices (such as MOSFETs or IGBTs) in the charging circuit 200. This adjusts the output charging voltage of the charging voltage 200 towards the preset charging voltage value, ultimately stabilizing the charging voltage at the preset value. Based on this, constant current, constant voltage, and variable voltage charging of the device to be charged 20 can be achieved, meeting the charging requirements of the vehicle battery.

[0042] The energy storage charging device provided in this embodiment, by integrating an energy storage device, a charging circuit, and a charging controller, enables efficient power replenishment for equipment such as electric trackless rubber-tired vehicles and electric monorail cranes in underground environments, significantly improving the utilization rate and transportation efficiency of underground electric vehicles. Specifically, by setting up an energy storage charging device underground, the device can be fully charged and then placed in the mine. This allows electric vehicles to travel to the charging device and recharge using the stored energy, eliminating the need for frequent trips to the surface for charging. This reduces the time spent traveling between the underground and surface, thereby greatly improving the utilization rate of underground electric vehicles.

[0043] In an optional embodiment, such as Figure 2 As shown, the charging circuit includes a DC input circuit 210, a DC output circuit 220, and multiple chopper circuits 230. Here, the charging controller may include a main controller and a back-end controller. The main controller and the back-end controller can be computer devices such as digital signal processors or microcontrollers. The main controller is used to connect to a remote host computer, receive a preset charging voltage value sent by the host computer, and send the preset charging voltage value to the back-end controller. Furthermore, the back-end controller can collect the charging voltage and charging current output by the charging circuit to the device 20 to be charged based on voltage and current sensors located at the output terminal of the charging circuit.

[0044] Specifically, the positive input terminal of the DC input circuit 210 is connected to the positive terminal of the energy storage device 100, the positive output terminal of the DC input circuit 210 is connected to the positive input terminal of each of the chopper circuits 230, the negative input terminal of the DC input circuit 210 is connected to the negative terminal of the energy storage device 100, and the negative output terminal of the DC input circuit 210 is connected to the negative input terminal of each of the chopper circuits 230; wherein, the DC input circuit 210 includes a first switch K1, a second switch K2, a second resistor R2, a third resistor R3, and a second capacitor C2.

[0045] Furthermore, the connection terminal of the DC output terminal of each chopper circuit 230 is connected to the positive terminal of the DC output circuit 220. Here, an inductor L01 can be connected in series between the DC output terminal of each chopper circuit 230 and the positive terminal of the DC output circuit 220. The inductor L01 connected to each chopper circuit 230 is different. Here, there can be three chopper circuits.

[0046] Furthermore, the negative terminal of the DC output circuit 220 is connected to the negative input terminal of each of the chopper circuits 230; the positive output terminal of the DC output circuit 220 is used to connect to the positive terminal of the device to be charged 20 to output the charging current and charging voltage to the device to be charged; the negative output terminal of the DC output circuit 220 is used to connect to the negative terminal of the device to be charged 20.

[0047] Furthermore, such as Figure 3 As shown, each chopper circuit includes an insulated-gate bipolar transistor (IGBT) Q01, a first diode D1, a second diode D2, and a first circuit capacitor C01. Here, the insulated-gate bipolar transistor Q01 can be used as a bridge arm switch of the chopper circuit, and the gate terminal of the insulated-gate bipolar transistor Q01 can be used as the control terminal of the bridge arm switch of the chopper circuit.

[0048] Specifically, the collector of the insulated-gate bipolar transistor Q01 and the cathode of the first diode D1 are connected in parallel to the first terminal of the first circuit capacitor C01. The positive input terminal 231 of the chopper circuit is led out between the collector of the insulated-gate bipolar transistor Q01 and the cathode of the first diode D1 and the first terminal of the first circuit capacitor C01. The emitter of the insulated-gate bipolar transistor Q01 and the anode of the first diode D1 are connected to the cathode of the second diode D2. The DC output terminal 233 of the chopper circuit is led out between the emitter of the insulated-gate bipolar transistor Q01 and the cathode of the second diode D2. The anode of the second diode D2 is connected to the second terminal of the first circuit capacitor C01 and leads out the negative input terminal 232 of the chopper circuit.

[0049] Furthermore, the control terminal of the bridge arm switch within the chopper circuit is connected to the control terminal of the charging controller, which controls the lower bridge switch to be in an on / off state. Specifically, the gate terminal of the insulated-gate bipolar transistor Q01 in each chopper circuit can be connected to the charging controller to be turned on or off under the control of the charging controller.

[0050] Specifically, when the duty cycle of the pulse width modulation signal sent by the charging controller to the gate terminal of the insulated gate bipolar transistor Q01 of each chopper circuit is greater than 0.5, the voltage value of the charging voltage output by the charging circuit can be increased. When the duty cycle of the pulse width modulation signal sent by the charging controller to the gate terminal of the insulated gate bipolar transistor Q01 of each chopper circuit is less than 0.5, the voltage value of the charging voltage output by the charging circuit can be decreased. And when the duty cycle of the pulse width modulation signal sent by the charging controller to the gate terminal of the insulated gate bipolar transistor Q01 of each chopper circuit is equal to 0.5, the voltage value of the charging voltage output by the charging circuit can be kept constant.

[0051] The embodiments provided in this application enable the charging controller to control the magnitude of the charging voltage output by the charging circuit by sending pulse width modulation signals with different duty cycles to the bridge arm switches of each chopper circuit in the charging circuit, thereby adjusting the charging voltage output by the charging circuit and improving the operability of the energy storage charging device.

[0052] In an optional embodiment, the charging controller adjusts the voltage output value of the charging circuit based on the collected charging voltage and charging current using a voltage-current dual-loop control algorithm, thereby stabilizing the charging voltage value at a preset charging voltage value. This includes:

[0053] First, the charging controller compares the preset charging voltage value with the collected charging voltage to obtain a voltage error signal, and performs outer loop voltage proportional-integral adjustment on the voltage error signal to generate a current setpoint.

[0054] Specifically, the charging controller collects the charging current and charging voltage output from the charging circuit to the device to be charged in real time, determines the current value and voltage value of the charging circuit, and calculates the difference between the preset charging voltage value and the actual charging voltage value in real time. This voltage difference is used as a voltage error signal, and its amplitude is equal to the voltage difference. Further, the voltage error signal is subjected to outer-loop voltage proportional-integral regulation to obtain the current setpoint.

[0055] Then, the current setpoint is limited to obtain the current target value for inner loop current control, and the current target value is compared with the charging current to obtain the current difference; specifically, the real-time current setpoint is limited to obtain the current target value, and the difference between the current target value and the charging current is obtained to obtain the current difference.

[0056] Next, the current difference is adjusted using an inner-loop proportional-integral (PI) current adjustment to obtain a target duty cycle value. Based on this target duty cycle value, multiple back-end pulse width modulation (PWM) signals are generated, with a phase difference of 120 degrees between each PWM signal. Specifically, the current difference is adjusted using an inner-loop PI current adjustment, and the adjusted parameters are then limited to obtain the target duty cycle value. The limiting value is set to the maximum duty cycle value of 0.95. Further, if the charging circuit contains three chopper circuits, the multiple back-end PWM signals generated by the PWM generator can be a first PWM signal, a second PWM signal, and a third PWM signal with the same duty cycle. The phase difference between the first and second PWM signals, and the phase difference between the second and third PWM signals, is 120 degrees.

[0057] Finally, multiple back-end pulse width modulation (PWM) signals are sent to the control terminals of the bridge arm switches in different chopper circuits, so that the charging voltage gradually approaches and stabilizes at the preset charging voltage value. Here, the back-end PWM signals received by the control terminals of each bridge arm switch are different. Specifically, the first PWM signal can be sent to the control terminal of the bridge arm switch of the chopper circuit closest to the energy storage device in the charging circuit, the second PWM signal can be sent to the control terminal of the bridge arm switch of the chopper circuit next closest to the energy storage device, and the corresponding PWM signals can continue to be sent to the control terminals of the corresponding bridge arm switches in subsequent chopper circuits in sequence, so as to control and adjust the charging voltage output by the charging circuit.

[0058] Here, the process of adjusting the voltage output value of the charging circuit using a dual-loop voltage and current control algorithm is as follows: Figure 4 As shown, U * dc is the preset charging voltage value, U1 is the charging voltage value, ΔU is the voltage error signal, PI is the proportional-integral regulator, Li1 is the first limiting module used to limit the real-time current setpoint, Li2 is the second limiting module used to limit the parameters after the inner loop current proportional-integral regulation, and I * dc is the target current value, I1 is the charging current value, ΔI is the current difference, and Duty is a PWM generator used to send the back-end pulse width modulation signal to the bridge arm switch of the charging circuit 200. The embodiments provided in this application can adjust the voltage output value of the charging circuit based on a voltage-current dual-loop control algorithm, improving the controllability of the energy storage charging device.

[0059] In an optional embodiment, such as Figure 5 As shown, the energy storage charging device further includes an energy access circuit 300; specifically, the discharge terminal of the energy access circuit 300 is connected to the energy storage device 100, and the charging terminal of the energy access circuit 300 is used to connect to an external power source E. When connected to the external power source E, the energy access circuit 300 is used to access charging energy from the external power source E and charge the energy storage device 100 based on the charging energy.

[0060] Here, the electrical power supply circuit 100 can be connected to an external power source E in the underground tunnel chamber or on the surface of the coal mine to fully charge the energy storage device 100, i.e., replenish its power. Furthermore, when the mobile vehicle 10 is an electric vehicle, the power source for the electric vehicle can also come from the energy storage device 100. It can be seen that the energy storage device 100 also assumes the role of a power battery for the electric vehicle. In terms of its capacity, it will be more than twice the capacity of a typical underground auxiliary transport vehicle, and can serve as a high-capacity energy storage power battery.

[0061] Furthermore, the charging controller (not shown in the figure) is electrically connected to the power access circuit 300. The charging controller is also used to collect the output current and output voltage output by the power access circuit 300 when charging the energy storage device 100 in real time, and adjust the current output value of the power access circuit 300 through a voltage and current dual-loop control algorithm based on the collected output current and output voltage, so that the current value of the output current of the power access circuit 300 is stabilized at a preset output current value.

[0062] In actual operation, the charging terminal of the power access circuit 300 can be connected to an external power source E. At this time, the charging controller can receive the preset output current value from the host computer, which is the target current value of the charging current for the energy storage device 100. It can also collect the voltage value of the output voltage and the current value of the output current from the power access circuit 300 to the energy storage device 100 in real time. The current output value of the power access circuit 300 is adjusted through the voltage and current dual-loop control algorithm to stabilize the current value of the output current from the power access circuit 300 to the energy storage device 100 at the preset charging current value.

[0063] The embodiments provided in this application can adjust the charging current to the energy storage device based on a voltage and current dual-loop control algorithm, thereby achieving constant current control for charging the energy storage device. Furthermore, the charging current of the energy storage device can be continuously adjusted by changing the preset output current value.

[0064] In an optional embodiment, the charging controller may further include a front-end controller, which may be a computer device such as a digital signal processor or a microcontroller. Here, the main controller is used to connect to a remote host computer, receive a preset charging current value sent by the host computer, and send the preset charging current value to the front-end controller. Further, the front-end controller may collect the voltage value of the output voltage and the current value of the output current from the power access circuit to the energy storage device based on the voltage collector and current collector set at the discharge terminal of the power access circuit.

[0065] Furthermore, such as Figure 6 As shown, the power access circuit includes an AC access circuit 310, a rectifier circuit 320, an H-bridge inverter circuit 330, and a DC output circuit 340.

[0066] Specifically, the AC input circuit 310 is used to connect to an external power source to receive AC power and deliver the AC power to the rectifier circuit 320. The AC input circuit 310 may include a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, a fourth resistor R4, and a fifth resistor R5. The AC input circuit 310 can connect to an external power source through its high-voltage charging terminal H or its low-voltage charging terminal L to receive AC power.

[0067] Furthermore, the rectifier circuit 320 is used to convert the alternating current into direct current and send the direct current to the H-bridge inverter circuit 330. Here, the rectifier circuit 320 includes a sixth resistor R6, a seventh resistor R7, a third capacitor C3, a fourth capacitor C4, and six rectifier units, including a first rectifier unit E1, a second rectifier unit E2, a third rectifier unit E3, a fourth rectifier unit E4, a fifth rectifier unit E5, and a sixth rectifier unit E6. The first terminals of the first rectifier unit E1, the second rectifier unit E2, and the third rectifier unit E3 are respectively connected to the first terminal of the third capacitor C3; the second terminal of the first rectifier unit E1 is connected to the first terminal of the fourth rectifier unit E4; the second terminal of the second rectifier unit E2 is connected to the first terminal of the fifth rectifier unit E5; the second terminal of the third rectifier unit E3 is connected to the first terminal of the sixth rectifier unit E6; and the second terminals of the fourth rectifier unit E4, the fifth rectifier unit E5, and the sixth rectifier unit E6 are connected to the fourth capacitor C4.

[0068] Furthermore, such as Figure 7 As shown, each rectifier unit includes a first circuit diode D01, a second circuit diode D02, a third circuit capacitor C03, and a fourth circuit capacitor C04. The connection point where the cathode of the first circuit diode D01 is connected to the first terminal of the third circuit capacitor C03 serves as the first terminal of the rectifier unit, and the connection point where the anode of the second circuit diode D02 is connected to the first terminal of the fourth circuit capacitor C04 serves as the second terminal of the rectifier unit.

[0069] Furthermore, the H-bridge inverter circuit 330 is used to invert the DC power into AC power under the control of the charging controller, and output the AC power to the DC output circuit 340. Here, the H-bridge inverter circuit 330 can be controlled by the charging controller to receive the DC power and output an AC current with a preset output current value, and send the AC current with the preset output current value to the DC output circuit 340. Specifically, the H-bridge inverter circuit 330 includes a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, and eight switching transistors as switching devices, including a first switching transistor IG1, a second switching transistor IG2, a third switching transistor IG3, a fourth switching transistor IG4, a fifth switching transistor IG5, a sixth switching transistor IG6, a seventh switching transistor IG7, and an eighth switching transistor IG8.

[0070] Among them, such as Figure 6 In the diagram, the upper part of each switching transistor represents its collector terminal, and the lower part represents its emitter terminal. Furthermore, the structure of each switching transistor is as follows: Figure 8 As shown, the switching transistor includes a transistor Q1 and a freewheeling diode Da. The collector of transistor Q1 and the cathode of freewheeling diode Da are connected in parallel to form the collector of the switching transistor. The emitter of transistor Q1 and the anode of freewheeling diode Da are connected in parallel to form the emitter of the switching transistor. The base of transistor Q1 is connected to the front-end controller (not shown in the figure) in the charging controller and is used to control whether it is in a conducting state or a disconnecting state, so that the switching transistor is in a conducting state or a disconnecting state.

[0071] Here, the H-bridge inverter circuit 330 includes a first bridge arm and a second bridge arm. The first bridge arm includes a first upper bridge arm and a first lower bridge arm. The first switch IG1 and the second switch IG2 constitute the first upper bridge arm, and the third switch IG3 and the fourth switch IG4 constitute the first lower bridge arm. Further, the second bridge arm includes a second upper bridge arm and a second lower bridge arm. The fifth switch IG5 and the sixth switch IG6 constitute the second upper bridge arm, and the seventh switch IG7 and the eighth switch IG8 constitute the second lower bridge arm.

[0072] Here, the charging controller controls the H-bridge inverter circuit to receive the DC power and output an AC current with a preset output current value, including:

[0073] First, the charging controller compares the preset output current value with the acquired output current to obtain a current error signal, and performs outer loop current proportional-integral regulation on the current error signal to generate a voltage setpoint. Specifically, the front-end controller in the charging controller can subtract the current value of the output current acquired in real time by the current acquisition device from the preset output current value, use the digital value of the current difference as the signal amplitude to obtain a current error signal, and perform outer loop voltage proportional-integral regulation and output limiting processing on the current error signal to generate a voltage setpoint.

[0074] Then, an inner-loop voltage proportional-integral regulator is applied to the difference between the voltage setpoint and the acquired output voltage to obtain the phase shift angle target value. Specifically, the front-end controller can subtract the voltage value of the output voltage acquired in real time by the voltage acquisition device from the voltage setpoint to obtain the voltage difference value, and apply an inner-loop voltage proportional-integral regulator to the voltage difference value to obtain the phase shift angle. The phase shift angle is then subjected to phase shift angle limiting processing to obtain the phase shift angle target value. This phase shift angle target value is used to generate a pulse width adjustment signal that is output to the base of transistor Q1 in the switching transistor.

[0075] Then, a first front-end pulse width modulation signal and a second front-end pulse width modulation signal are generated based on the target phase angle value, wherein the phase difference between the first front-end pulse width modulation signal and the second front-end pulse width modulation signal is 180 degrees; here, the first front-end pulse width modulation signal in the form of a pulse width modulation signal with a specific duty cycle can be generated based on the phase shift pulse controller based on the target phase angle value, and the phase of the first front-end pulse width modulation signal can be adjusted by 180 degrees to obtain the second front-end pulse width modulation signal.

[0076] Finally, the first upper bridge arm and the second lower bridge arm are turned on and off based on the first front-end pulse width modulation signal. Specifically, the first front-end pulse width modulation signal can be sent to the base of each transistor in the first upper bridge arm and the base of each transistor in the second lower bridge arm to control the turn-on and turn-off of the first upper bridge arm and the second lower bridge arm.

[0077] Furthermore, the second upper bridge arm and the first lower bridge arm are controlled to turn on and off based on the second front-end pulse width modulation signal. Specifically, the second front-end pulse width modulation signal can be sent to the base of each transistor in the second upper bridge arm and the base of each transistor in the first lower bridge arm to control the turn-on and turn-off of the second upper bridge arm and the first lower bridge arm, so that the H-bridge inverter circuit outputs an AC current with a preset output current value.

[0078] Here, the flowchart illustrating how the charging controller adjusts the current output value of the power access circuit using a dual-loop voltage and current control algorithm is as follows: Figure 9 As shown, where, To preset the output current value, I dc ε1 is the output current value, and ε2 is the current error signal, which is the difference between the preset output current value and the actual output current value. This is the upper limit of the voltage limit. This is the lower limit of voltage limiting. Given a voltage value, U dc ε1 is the output voltage value, ε2 is the difference between the voltage setpoint and the acquired output voltage, and θ is the voltage value. gmax θ is the upper limit of the phase shift angle, SG is the target value of the phase shift angle, PI is the proportional-integral regulator, Li3 is the third limiting module used to perform output limiting processing on the parameters after the outer loop voltage proportional-integral regulation of the current error signal to generate the voltage setpoint, and Li4 is the fourth limiting module used to perform phase shift angle limiting processing to obtain the target value of the phase shift angle. The PWM signal generated by the phase shift pulse controller is sent to the H-bridge inverter circuit 330 to adjust the output current of the H-bridge inverter circuit 330.

[0079] Furthermore, the DC output circuit 340 is used to rectify the AC current of the preset output current value to obtain a DC output current of the preset output current value, and to charge the energy storage device (not shown in the figure) based on the output current. The embodiments provided in this application can adjust the output current of the power access circuit based on a voltage-current dual-loop control algorithm to output stable DC power to charge the energy storage device, thereby improving the stability of the energy storage charging device.

[0080] In an optional embodiment, such as Figure 10 As shown, the charging controller includes a main controller 410, a front-end controller 420, a back-end controller 430, and an operation panel 440. The main controller 410, front-end controller 420, and back-end controller 430 can each be processed by a DSP SMT28335 digital signal processor. Furthermore, the main controller 410 establishes communication connections with the front-end controller 420 and the back-end controller 430 via CAN bus communication and RS485 communication. Furthermore, the main controller 410 can establish a communication connection with a remote host computer 600 via Ethernet. The operation panel 440 is connected to the main controller 410 via I / O interfaces and AD sampling interfaces. The main controller 410 can be operated via buttons on the operation panel 440, which also includes alarm lights.

[0081] Furthermore, the front-end controller 420 and the back-end controller 430 have the same structure. The front-end controller 420 has a 6-channel digital output channel for controlling the opening and closing of the main switch, charging switch, discharging switch, and cooling fan switch of the power access circuit. The front-end controller 420 also has a 6-channel digital input channel for receiving feedback signals from the main switch and the charging switch. The front-end controller 420 also has a PWM signal output channel for sending PWM signals to each transistor in the first and second arms of the H-bridge inverter circuit. Here, a drive circuit can be provided between the front-end controller 420 and each transistor to amplify the PWM signal, thereby increasing the signal strength of the PWM signal sent to the base of the transistor. Furthermore, the front-end controller 420 also has a 5-channel sampling input channel for receiving the output voltage value, the output current value, the voltage and current values ​​of the power access circuit from the external power source, and can acquire the front-end temperature value of the power access circuit from a front-end temperature sensor located at the power access circuit.

[0082] Furthermore, the charging controller is also used to compare the charging voltage value with a preset voltage alarm threshold. When the charging voltage value exceeds the voltage alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in an open state. Specifically, the back-end controller in the charging controller can collect the charging voltage value output by the charging circuit in real time and compare the charging voltage value with the preset voltage alarm threshold. When the charging voltage value exceeds the voltage alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in an open state to cut off the charging operation to the device to be charged.

[0083] Furthermore, the charging controller is also used to compare the charging current value with a preset current alarm threshold. When the charging current value exceeds the current alarm threshold, it controls the bridge arm switch in each chopper circuit to be in an open state. Specifically, the back-end controller in the charging controller can collect the charging current value output by the charging circuit in real time and compare the charging current value with the preset current alarm threshold. When the charging current value exceeds the current alarm threshold, it controls the bridge arm switch in each chopper circuit to be in an open state to cut off the charging operation to the device to be charged.

[0084] Furthermore, the voltage alarm threshold may include a first voltage threshold and a second voltage threshold, and the current alarm threshold may include a first current threshold and a second current threshold, wherein the first voltage threshold is higher than the second voltage threshold, and the first current threshold is higher than the second current threshold. When the charging voltage is lower than the second voltage threshold and the charging current is lower than the second current threshold, it can be determined that there is no abnormality in the charging process. However, when the charging voltage is higher than the second voltage threshold but lower than the first voltage threshold, or the charging current is higher than the second current threshold but lower than the first current threshold, the back-end controller can determine that there is an abnormality in the charging process of the device to be charged. At this time, the main controller sends an abnormality alarm to the host computer to alert relevant personnel to the abnormal situation. When the charging voltage is higher than the first voltage threshold, or the charging current is higher than the first current threshold, the back-end controller can determine that there is a fault in the charging process of the device to be charged. At this time, the bridge arm switch in each chopper circuit is controlled to be in the open state to cut off the charging operation to the device to be charged, so as to ensure the charging safety of the device to be charged.

[0085] Similarly, the front-end controller can also implement the aforementioned voltage and current alarm and safety protection measures for the power access circuit, which will not be elaborated here. The embodiments provided in this application can monitor the voltage and current during the charging process of the device to be charged, and promptly stop the charging process when abnormal voltage or current occurs, thereby improving the safety of the energy storage charging device.

[0086] In an optional embodiment, the charging controller is further configured to collect the temperature value of the charging circuit and compare the temperature value with a preset temperature alarm threshold. When the temperature value exceeds the temperature alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in an open state. Specifically, the back-end controller in the charging controller can collect the temperature value of the charging circuit in real time and compare the temperature value with the temperature alarm threshold. When the temperature value exceeds the temperature alarm threshold, it can be determined that the charging circuit is overheating. At this time, the controller controls the bridge arm switch in each chopper circuit to be in an open state to stop the charging operation of the device to be charged. The temperature value of the charging circuit can be the average temperature of multiple preset temperature collection points of the charging circuit.

[0087] Here, the temperature alarm threshold may include a first temperature threshold and a second temperature threshold, with the first temperature threshold being higher than the second temperature threshold. When the temperature value is lower than the second temperature threshold, it can be determined that no temperature abnormality has occurred during the charging process of the device to be charged. When the temperature value is higher than the second temperature threshold but lower than the first temperature threshold, the back-end controller can determine that there is a temperature abnormality during the charging process of the device to be charged. At this time, the main controller sends an abnormality alarm to the host computer to alert relevant personnel to the abnormal situation. When the temperature value is higher than the first temperature threshold, the back-end controller can determine that there is a fault in the charging process of the device to be charged. At this time, it controls each bridge arm switch in each of the chopper circuits to be in the open state to cut off the charging operation to the device to be charged, thereby ensuring the charging safety of the device to be charged.

[0088] Similarly, the front-end controller can also implement the aforementioned temperature alarm and safety protection measures for the power access circuit, which will not be elaborated here. The embodiments provided in this application can monitor the temperature of the charging process of the device to be charged and stop the charging process in time when the temperature is abnormal, thereby improving the safety of the energy storage charging device.

[0089] In an optional embodiment, the bridge arm switch is an insulated gate bipolar transistor (IGBT). The back-end controller in the charging controller is further configured to acquire the voltage drop between the collector and emitter of each IGBT and compare the voltage drop with a preset voltage drop threshold. When the voltage drop exceeds the voltage drop threshold, it can be determined that the IGBT has a short circuit. At this time, the charging controller controls the bridge arm switch in each chopper circuit to be in the open state to prevent charging accidents from occurring during the charging process of the device to be charged.

[0090] Similarly, the front-end controller can determine the voltage drop value of each transistor in the H-bridge inverter circuit in the same way and compare it with a voltage drop threshold. When the voltage drop value exceeds the threshold, it can be determined that the transistor is short-circuited. At this time, the front-end controller controls each transistor in the H-bridge inverter circuit to be in the off state to provide short-circuit protection for the charging process of the energy storage device. The embodiments provided in this application can monitor whether the bridge arm switch is short-circuited and promptly cut off the charging process of the device to be charged when a short-circuited bridge arm switch is found, thereby improving the safety of charging the device to be charged.

[0091] The energy storage charging device provided in this application, by being installed underground, allows electric vehicles to travel to the energy storage charging device after it has been fully charged. The electric vehicles can then be charged using the stored energy, eliminating the need for frequent trips to the surface for charging. Furthermore, the energy storage charging device, mounted on a mobile vehicle platform underground in the coal mine, forms a mobile charger. This allows the mobile charger to move freely within the mine's roadways and connect to underground power sources for charging, improving its continuous charging capability and significantly enhancing the auxiliary transportation capacity of the coal mine. This creates favorable conditions for increasing production and efficiency for coal mining enterprises.

[0092] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of any particular implementation scenario. The above disclosures are merely a few specific implementation scenarios of this application; however, this application is not limited thereto, and any variations conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. An energy storage charging device, characterized in that, The energy storage charging device includes an energy storage device, a charging circuit, and a charging controller. The input terminal of the charging circuit is connected to the energy storage device, and the output terminal of the charging circuit is used to connect to an external device to be charged. When the charging circuit is connected to the device to be charged, the charging circuit is used to obtain electrical energy from the energy storage device and charge the device to be charged; The charging controller is electrically connected to the charging circuit and is used to collect the charging voltage and charging current output by the charging circuit to the device to be charged in real time. Based on the collected charging voltage and charging current, the controller adjusts the voltage output value of the charging circuit through a voltage and current dual-loop control algorithm to stabilize the charging voltage value at a preset charging voltage value.

2. The energy storage charging device according to claim 1, characterized in that, The charging circuit includes a DC input circuit, a DC output circuit, and multiple chopper circuits. The positive input terminal of the DC input circuit is connected to the positive terminal of the energy storage device, the positive output terminal of the DC input circuit is connected to the positive input terminal of each chopper circuit, the negative input terminal of the DC input circuit is connected to the negative terminal of the energy storage device, and the negative output terminal of the DC input circuit is connected to the negative input terminal of each chopper circuit. The connection terminal of each chopper circuit after its DC output terminal is connected is connected to the positive terminal of the DC output circuit, and the negative terminal of the DC output circuit is connected to the negative input terminal of each chopper circuit. The positive output terminal of the DC output circuit is used to connect to the positive terminal of the device to be charged, and the negative output terminal of the DC output circuit is used to connect to the negative terminal of the device to be charged, so as to output the charging current and the charging voltage to the device to be charged. The control terminal of the bridge arm switch in the chopper circuit is connected to the control terminal of the charging controller, and the charging controller is used to control the bridge arm switch to be in the on and off state.

3. The energy storage charging device according to claim 2, characterized in that, The charging controller, based on the collected charging voltage and charging current, adjusts the voltage output value of the charging circuit through a voltage-current dual-loop control algorithm to stabilize the charging voltage value at a preset charging voltage value, including: The charging controller compares the preset charging voltage value with the collected charging voltage to obtain a voltage error signal, and performs outer loop voltage proportional-integral adjustment on the voltage error signal to obtain a current setpoint. After limiting the current setpoint, a current target value for inner loop current control is obtained, and the current target value is compared with the charging current to obtain the current difference. The duty cycle target value is obtained by performing inner loop current proportional-integral adjustment on the current difference, and multiple back-end pulse width modulation signals are generated based on the duty cycle target value, wherein the phase difference between each back-end pulse width modulation signal is 120 degrees. Multiple back-end pulse width modulation signals are sent to the control terminals of different bridge arm switches in the chopper circuit to stabilize the charging voltage value at a preset charging voltage value.

4. The energy storage charging device according to claim 1, characterized in that, The energy storage charging device also includes an electrical energy access circuit. The discharge terminal of the power access circuit is connected to the energy storage device, and the charging terminal of the power access circuit is used to connect to an external power source. When connected to the external power source, the power access circuit is used to access charging power from the external power source and charge the energy storage device based on the charging power. The charging controller is electrically connected to the power access circuit. The charging controller is also used to collect the output current and output voltage of the power access circuit charging the energy storage device in real time, and based on the collected output current and output voltage, adjust the current output value of the power access circuit through a voltage and current dual-loop control algorithm to stabilize the output current value at a preset output current value.

5. The energy storage charging device according to claim 4, characterized in that, The power access circuit includes an AC access circuit, a rectifier circuit, an H-bridge inverter circuit, and a DC output circuit. The AC access circuit is used to connect to an external power source to receive AC power from the external power source and to deliver the AC power to the rectifier circuit; The rectifier circuit is used to convert the alternating current into direct current and send the direct current to the H-bridge inverter circuit; The H-bridge inverter circuit is used to invert the DC power into AC power under the control of the charging controller, and output the AC power to the DC output circuit. The DC output circuit is used to rectify the AC current to obtain an output current, and to charge the energy storage device based on the output current.

6. The energy storage charging device according to claim 5, characterized in that, The H-bridge inverter circuit includes a first bridge arm and a second bridge arm. The first bridge arm includes a first upper bridge arm and a first lower bridge arm, and the second bridge arm includes a second upper bridge arm and a second lower bridge arm. The charging controller controls the H-bridge inverter circuit to convert the DC power into AC power in the following ways: The charging controller compares the preset output current value with the collected output current to obtain a current error signal, and performs outer loop current proportional-integral adjustment on the current error signal to obtain a voltage setpoint. The difference between the voltage setpoint and the acquired output voltage is processed by an inner-loop voltage proportional-integral regulator to obtain the target phase shift angle value. A first front-end pulse width modulation signal and a second front-end pulse width modulation signal are generated based on the target phase shift angle value, wherein the first front-end pulse width modulation signal and the second front-end pulse width modulation signal have the same duty cycle and the phase difference between the first front-end pulse width modulation signal and the second front-end pulse width modulation signal is 180 degrees. The first upper bridge arm and the second lower bridge arm are controlled to turn on and off based on the first front-end pulse width modulation signal, and the second upper bridge arm and the first lower bridge arm are controlled to turn on and off based on the second front-end pulse width modulation signal, so that the H-bridge inverter circuit outputs an AC current with a preset output current value.

7. The energy storage charging device according to claim 3, characterized in that, The charging controller is also used to compare the voltage value of the charging voltage with a preset voltage alarm threshold. When the voltage value of the charging voltage exceeds the voltage alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in the open state to stop the charging operation of the device to be charged. The charging controller is also used to compare the current value of the charging current with a preset current alarm threshold. When the current value of the charging current exceeds the current alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in the open state to stop the charging of the device to be charged.

8. The energy storage charging device according to claim 3, characterized in that, The charging controller is also used to collect the temperature value of the charging circuit and compare the temperature value with a preset temperature alarm threshold. When the temperature value exceeds the temperature alarm threshold, the controller controls the bridge arm switch in each chopper circuit to be in the open state to stop the charging of the device to be charged.

9. The energy storage charging device according to claim 3, characterized in that, The bridge arm switch is an insulated gate bipolar transistor; The charging controller is also used to collect the voltage drop value of each of the insulated gate bipolar transistors and compare the voltage drop value with a preset voltage drop threshold. When the voltage drop value exceeds the voltage drop threshold, the controller controls the bridge arm switch in each of the chopper circuits to be in the open state to stop the charging operation of the device to be charged.

10. The energy storage charging device according to claim 1, characterized in that, The charging controller establishes a communication connection with a remote host computer via Ethernet communication, bus communication, and serial communication.

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