Energy storage system for recovering kinetic energy of winch

Abstract

The invention provides an energy storage system for recovering kinetic energy of a winch, and relates to the technical field of energy storage systems. The system comprises a power supply input module, a battery energy storage module, a first bidirectional converter and a rectifier, one end of the first bidirectional transducer is connected with the battery energy storage module, and the other end of the first bidirectional transducer is connected with the direct-current bus; one end of the rectifier is connected with the power input module through the AC bus, and the other end is connected with the DC bus. When the winch is in a descending operation condition, the electric energy generated by the motor is transmitted and stored to the battery energy storage module through the direct current bus; when the winch is in a rising operation condition, power is supplied to the motor through the battery energy storage module and the power input module. The working mode is changed based on the operation condition of the winch, kinetic energy generated when the winch descends is converted into electric energy to charge the battery energy storage module, supplementary power is additionally provided when the winch ascends, the kinetic energy of the winch is effectively recycled, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of energy storage system technology, and more specifically, to an energy storage system for recovering kinetic energy from a winch. Background Technology

[0002] Currently, oilfield workover rigs typically consist of a diesel generator, winch, pump truck, and braking resistor, all integrated onto a trailer and moved for operation via tractor-trailer traction. In particular, during the winch's descent with a load, the significant gravitational potential and kinetic energy released by the heavy load due to the high derrick height is substantial. However, in traditional energy storage systems, this released gravitational potential and kinetic energy is typically dissipated as heat after being converted into electrical energy by an electric motor. This not only wastes energy but also increases the heat dissipation burden and operating costs. Furthermore, during the winch's hoisting process, the required high power is provided instantaneously by the diesel generator, further exacerbating the generator's load fluctuations.

[0003] Therefore, how to effectively recover and utilize the remaining kinetic energy of the winch and improve energy efficiency is an urgent problem to be solved in this field. Summary of the Invention

[0004] The purpose of this application is to provide an energy storage system for recovering kinetic energy from winches, addressing the shortcomings of the prior art, in order to solve the problems of ineffective recovery and utilization of the remaining kinetic energy of winches and low energy utilization efficiency in the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: This application provides an energy storage system for recovering kinetic energy from a winch. The system includes: a power input module, a battery energy storage module, a first bidirectional converter, and a rectifier. One end of the first bidirectional converter is connected to the battery energy storage module, and the other end of the first bidirectional converter is connected to the DC bus, and the motor of the winch is connected to the DC bus; One end of the rectifier is connected to the power input module via an AC bus, and the other end of the rectifier is connected to the DC bus. The rectifier is used to convert the AC power input to the power input module into DC power and output the DC power to the DC bus. When the winch is in the descent operation mode, the electrical energy generated by the motor is transmitted through the DC bus and stored in the battery energy storage module; When the winch is in the ascending operation mode, power is supplied to the motor of the winch through the battery energy storage module and the power input module.

[0006] As one possible implementation, the system further includes: a frequency converter, one end of which is connected to the motor of the winch, and the other end of which is connected to the DC bus; When the winch is in a descending operating condition, the electrical energy generated by the motor is transmitted via the DC bus and stored in the battery energy storage module, including: When the winch is in the descent operation mode, the frequency converter converts the AC power generated by the motor into DC power and outputs the DC power to the DC bus, so that the voltage of the DC bus begins to rise; When the current voltage of the DC bus rises to a level greater than the first threshold, the first bidirectional converter switches to a high-window constant-voltage charging mode, obtains DC power generated and converted by the motor from the DC bus, performs a step-down operation to obtain stepped-down DC power, and outputs the stepped-down DC power to the battery energy storage module to charge the battery energy storage module.

[0007] As one possible implementation, when the winch is in an ascending operation, supplying power to the winch's motor via the battery energy storage module and the power input module includes: When the winch is in the ascending operation mode, the winch motor draws electrical energy from the DC bus to cause the voltage of the DC bus to begin to drop; When the current voltage of the DC bus drops below the second threshold, the first bidirectional converter switches to a low-window constant voltage discharge mode to transmit the electrical energy stored in the battery energy storage module to the DC bus. The frequency converter obtains target DC power from the DC bus and converts the target DC power into AC power, and outputs the AC power to the motor to supply power to the motor. The target DC power includes the electrical energy transmitted to the DC bus by the battery energy storage module and the power input module.

[0008] As one possible implementation, the battery energy storage module includes a first battery cluster and a second battery cluster, wherein the first battery cluster and the second battery cluster are connected in parallel.

[0009] As one possible implementation, the battery energy storage module further includes: a first high-voltage control box; The first battery cluster includes multiple first battery modules, each of which is connected in series. The positive terminal of the first first battery module is connected to the positive terminal of the battery side of the first high-voltage control box, and the negative terminal of the last first battery module is connected to the negative terminal of the battery side of the first high-voltage control box.

[0010] As one possible implementation, the battery energy storage module further includes: a second high-voltage control box; The second battery cluster includes multiple second battery modules, each of which is connected in series. The positive terminal of the first second battery module is connected to the positive terminal of the battery side of the second high-voltage control box, and the negative terminal of the last second battery module is connected to the negative terminal of the battery side of the second high-voltage control box.

[0011] As one possible implementation, the first high-voltage control box and the second high-voltage control box include at least: a DC contactor and a battery main control management unit; The battery master control management unit is used to detect the operating information of the first battery cluster or the second battery cluster, and determine whether the first battery cluster or the second battery cluster is operating abnormally based on the operating information. If so, it controls the DC contactor to disconnect. The operating information includes voltage, current and temperature.

[0012] As one possible implementation, the system further includes: a second bidirectional converter, one end of which is connected to the second battery cluster, and the other end of which is connected to the AC bus; The second bidirectional converter is used to convert the AC power output from the power input module into DC power to charge the battery energy storage module; The second bidirectional converter is also used to invert the DC power stored in the battery energy storage module into AC power to supply power to the load device.

[0013] As one possible implementation, the power input module includes a main power supply, a backup power supply, and a transfer switch; The transfer switch is used to connect to the backup power supply when the main power supply is disconnected, so as to output AC power through the backup power supply; The transfer switch is also used to disconnect from the backup power supply and reconnect to the main power supply when the main power supply is restored, so as to output AC power through the main power supply.

[0014] As one possible implementation, the system further includes: a braking resistor connected to the DC bus, the braking resistor being used to dissipate excess electrical energy, the excess electrical energy being the excess electrical energy generated by the winch motor when the winch is performing a descent operation.

[0015] An energy storage system for recovering kinetic energy from a winch, according to an embodiment of this application, includes a power input module, a battery energy storage module, a first bidirectional converter, and a rectifier. One end of the first bidirectional converter is connected to the battery energy storage module, and the other end is connected to a DC bus. The winch motor is also connected to the DC bus. One end of the rectifier is connected to the power input module via an AC bus, and the other end is connected to the DC bus. The rectifier converts the AC power input to the power input module into DC power and outputs the DC power to the DC bus. Based on this, when the winch is in a descending operation, the electrical energy generated by the motor is transmitted via the DC bus and stored in the battery energy storage module. When the winch is in an ascending operation, power is supplied to the winch motor through the battery energy storage module and the power input module. According to the embodiments of this application, when the winch is in the descending operation mode, the motor operates in a generator state, converting the gravitational potential energy during the lowering process into electrical energy. This electrical energy is transmitted through the DC bus and controlled by the first bidirectional converter to charge the battery energy storage module, achieving efficient recovery and storage of kinetic energy. This avoids the drawback of wasting energy as heat through braking resistors in traditional systems. When the winch is in the ascending operation mode, the power input module and the battery energy storage module work together to provide power. That is, while the rectifier rectifies the AC power into DC power to supply the motor, the battery energy storage module releases the stored energy through the first bidirectional converter, jointly providing power support for the winch hoisting operation, reducing the load on the main power supply module, and improving the system's responsiveness and operational stability. Based on this, not only is the kinetic energy of the winch effectively recovered and utilized, but energy utilization efficiency is also effectively improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This illustration shows a schematic diagram of the architecture of an energy storage system for winch kinetic energy recovery provided in an embodiment of this application; Figure 2 This illustration shows a schematic diagram of another energy storage system for winch kinetic energy recovery provided in an embodiment of this application; Figure 3 A schematic diagram of the architecture of a battery energy storage module provided in an embodiment of this application is shown; Figure 4 This paper shows a connection diagram of a second bidirectional converter provided in an embodiment of this application; Figure 5A schematic diagram of the architecture of a power input module provided in an embodiment of this application is shown; Figure 6 This illustration shows a schematic diagram of the architecture of another energy storage system for winch kinetic energy recovery provided in an embodiment of this application.

[0018] Icons: 10-Power input module; 11-Battery storage module; 12-First bidirectional converter; 13-Rectifier; 14-Wind; 15-Inverter; 16-Second bidirectional converter; 17-Braking resistor; 18-Inverter module; 19-Load device; 101-First battery cluster; 102-Second battery cluster; 103-First high-voltage control box; 104-Second high-voltage control box; 105-Main power supply; 106-Backup power supply; 107-Changeover switch. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0020] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0022] In existing technologies, workover rigs used in oilfields consist of a diesel generator, winch, pump truck, and braking resistor, all mounted on a trailer and transported by the tractor unit to various oilfield well sites. Workover rigs rely entirely on diesel generators for power, resulting in high energy consumption, large emissions, and environmental pollution. Furthermore, the generator operates under variable load conditions for extended periods, making it difficult to operate within its optimal economic range. Overload or malfunction can easily lead to system failure, affecting the normal operation of smaller equipment. During operations, the winch frequently raises and lowers heavy loads, approaching 20 tons, while the derrick reaches heights of nearly 20 meters. The significant amount of gravitational potential and kinetic energy generated during descent is not recovered but consumed as heat through the braking resistor, leading to energy waste, increased operating costs, and potential heat dissipation and safety hazards.

[0023] To address the aforementioned issues, this application provides an energy storage system for recovering kinetic energy from a winch. During the winch's descent, the electric motor operates as a generator, and the energy storage system automatically operates in a high-window constant-voltage mode, recovering a portion of the electrical energy converted from potential energy to charge the battery energy storage module. During the winch's ascent, the energy storage system automatically operates in a low-window constant-voltage mode, providing the power required for the winch to drive the load upwards, thus maintaining normal system operation. In this way, the energy storage system of this application changes its operating mode according to the winch's operating conditions, supplementing the power needed for the winch's ascent and recovering the remaining kinetic energy during the winch's descent, making the entire energy storage system more energy-efficient, safer, and more reliable.

[0024] The following provides a detailed description of an energy storage system for recovering kinetic energy from a winch, as provided in an embodiment of this application.

[0025] Figure 1 A schematic diagram of the architecture of an energy storage system for winch kinetic energy recovery provided in an embodiment of this application is shown. (Refer to...) Figure 1 As shown, the energy storage system includes: a power input module 10, a battery energy storage module 11, a first bidirectional converter 12, and a rectifier 13. One end of the first bidirectional converter 12 is connected to the battery energy storage module 11, and the other end of the first bidirectional converter 12 is connected to the DC bus. The winch motor is also connected to the DC bus.

[0026] Optionally, one end of the rectifier 13 is connected to the power input module 10 via an AC bus, and the other end of the rectifier 13 is connected to a DC bus. The rectifier 13 is used to convert the AC power input to the power input module 10 into DC power and output the DC power to the DC bus.

[0027] Optionally, the power input module 10 serves as the main power input terminal of the energy storage system, providing power support for the entire system. The rectifier 13 is connected between the AC bus and the DC bus, converting the AC power provided by the power input module 10 into DC power and feeding it into the DC bus to power subsequent loads and provide a stable DC voltage for the battery energy storage module 11. The first bidirectional converter 12 is connected to the battery energy storage module 11 at one end and to the DC bus at the other, enabling bidirectional energy flow. During charging, the first bidirectional converter 12 converts the electrical energy on the DC bus into a voltage / current form suitable for storage in the battery energy storage module 11, charging it. During discharging, it regulates the DC power released by the battery energy storage module 11 and feeds it back to the DC bus for load use. The battery energy storage module 11 consists of multiple rechargeable and dischargeable battery modules used to store electrical energy and release it when needed to supplement system power requirements. The motor of winch 14 is directly connected to the DC bus. As the main electrical load of the energy storage system, the operating state of the motor of winch 14 determines the direction of energy flow.

[0028] Optionally, when the winch 14 is in a descending operation, the electrical energy generated by the motor of the winch 14 is transmitted via the DC bus and stored in the battery energy storage module 11.

[0029] For example, when the winch 14 descends with a load, the gravitational potential energy of the load drives the motor of the winch 14 to rotate. At this time, the motor enters the power generation mode, converting mechanical energy into electrical energy and feeding it back to the DC bus. This converted electrical energy can be transmitted to the battery energy storage module 11 for charging and storage through the first bidirectional converter 12, thereby realizing the recovery and utilization of kinetic energy and avoiding the waste of energy dissipated through the braking resistor in the traditional method.

[0030] Optionally, when the winch 14 is in the rising operation mode, power is supplied to the motor of the winch 14 through the battery energy storage module 11 and the power input module 10.

[0031] For example, when the winch 14 lifts a heavy object, the motor is in "electric mode" and consumes a large amount of electrical energy. At this time, the system supplies power from two directions: on the one hand, the power input module 10 provides basic power through the rectifier 13; on the other hand, if the current load demand exceeds the main power supply capacity, the first bidirectional converter 12 will control the battery energy storage module 11 to release the stored electrical energy, which is then converted and injected into the DC bus to jointly power the motor, thereby relieving the power supply pressure on the main power supply module 10.

[0032] Based on this, the energy storage system for winch kinetic energy recovery provided in this application can assist in providing the power required for upward movement when the winch load is too high, preventing overload and overcurrent in the power input module, ensuring the safe operation of the energy storage system, fully utilizing the downward kinetic energy of the winch, reducing the impact of excessive kinetic energy on the braking resistor, and making the operation more efficient. Simultaneously, it can promptly supplement or recover insufficient or excess power from the winch, making the energy storage system operate more smoothly and reliably. The energy storage system for winch kinetic energy recovery provided in this application can be used for power supplementation and charging / discharging during winch operation, converting the kinetic energy of the winch's descent into electrical energy to charge the battery energy storage module, and providing additional supplementary power for the winch's upward movement, achieving a certain degree of self-charging and self-discharging.

[0033] Figure 2 A schematic diagram of another energy storage system for winch kinetic energy recovery provided in an embodiment of this application is shown. (Refer to...) Figure 2 As shown, the energy storage system also includes a frequency converter 15, one end of which is connected to the motor of the winch 14, and the other end of which is connected to the DC bus.

[0034] Optionally, the frequency converter 15 is a key power electronic device connecting the motor of the winch 14 to the DC bus. One end of it is connected to the motor of the winch 14, and the other end is connected to the DC bus, enabling precise control of the motor's operating status and bidirectional energy flow management. The frequency converter 15 is a typical DC-AC conversion device, such as a DC / AC inverter.

[0035] Optionally, when the winch 14 lifts a heavy object, the DC bus provides DC power, which is inverted by the frequency converter 15 into three-phase AC power with adjustable frequency and voltage, supplying the motor of the winch 14 to drive its operation, achieving precise speed regulation and efficient traction. When the winch 14 descends with a load, the motor of the winch 14 enters a generator state under the action of gravity, generating electrical energy and feeding it back to the frequency converter 15. At this time, the frequency converter 15 rectifies the AC power output from the motor into DC power and sends it to the DC bus, which is used by the first bidirectional converter 12 to charge the battery energy storage module 11, thereby realizing kinetic energy recovery and electrical energy reuse.

[0036] In addition, the inverter 15 can also dynamically respond to changes in system load by adjusting the current direction and power flow direction, ensuring the stability of the DC bus voltage and avoiding system fluctuations caused by sudden increases or decreases in energy.

[0037] Furthermore, when the winch is in a descending operation, the electrical energy generated by the motor is transmitted through the DC bus and stored in the battery energy storage module. This includes: when the winch is in a descending operation, the frequency converter converts the AC power generated by the motor into DC power and outputs the DC power to the DC bus so that the voltage of the DC bus starts to rise. When the current voltage of the DC bus rises to a level greater than a first threshold, the first bidirectional converter switches to a high-window constant voltage charging mode, obtains the DC power generated and converted by the motor from the DC bus and performs a step-down operation to obtain the stepped-down DC power, and outputs the stepped-down DC power to the battery energy storage module to charge the battery energy storage module.

[0038] For example, the winch 14 is in a descending operation mode, meaning the motor of the winch 14 is in generator mode. When the winch 14 is in a descending operation mode, the motor of the winch 14 enters a regenerative power generation state under the action of gravity, generating alternating current (AC). The frequency converter 15, as a key energy conversion device, first rectifies this AC power into direct current (DC) power and outputs it to the DC bus, causing the DC bus voltage to gradually increase. When the current voltage of the DC bus is detected to rise above a preset first threshold, it can be determined that there is sufficient feedback energy available for energy storage. At this time, the first bidirectional converter 12 automatically switches to a high-window constant-voltage charging mode, which is also a constant-voltage current-limiting mode, to actively absorb electrical energy from the DC bus.

[0039] For example, since the charging voltage of the battery energy storage module 11 is typically lower than the DC bus voltage, the first bidirectional converter 12 uses a built-in DC-DC step-down circuit to step down the acquired DC power, converting it to a voltage and current level suitable for the safe charging of the battery energy storage module 11, and then delivers the stepped-down DC power to the battery energy storage module 11, achieving efficient energy storage. This process not only effectively utilizes the regenerative kinetic energy generated during winch descent, but also ensures the stability of the charging process and the safety of the system voltage through voltage threshold control and mode switching mechanisms, avoiding the risk of DC bus overvoltage due to excessive energy feedback, and realizing intelligent coordinated control of energy recovery and battery charging.

[0040] Furthermore, when the winch is in an ascending operation, power is supplied to the winch motor through the battery energy storage module and the power input module. This includes: when the winch is in an ascending operation, the winch motor obtains electrical energy from the DC bus to cause the DC bus voltage to begin to drop. When the current DC bus voltage drops below a second threshold, the first bidirectional converter switches to a low-window constant-voltage discharge mode, transferring the electrical energy stored in the battery energy storage module to the DC bus. The frequency converter obtains the target DC power from the DC bus and converts the target DC power into AC power, and outputs the AC power to the motor to supply power to the motor.

[0041] For example, the winch 14 is in an ascending operation mode, meaning the motor of the winch 14 is in electric mode. When the winch 14 is in an ascending operation mode, the motor of the winch 14 requires a large amount of electrical energy to lift the heavy load. At this time, the motor obtains electrical energy from the DC bus through the frequency converter 15 to drive the operation, causing the DC bus voltage to gradually decrease. When the current voltage of the DC bus is detected to drop below a preset second threshold, it indicates that the power supply alone from the main power supply module 10 is insufficient to meet the instantaneous high power demand, or there is a risk of bus voltage instability. At this time, the control energy storage system triggers an energy replenishment mechanism.

[0042] Specifically, the first bidirectional converter 12 automatically switches to a low-window constant-voltage discharge mode, entering an active discharge state. It outputs the pre-stored DC energy in the battery energy storage module 11 to the DC bus via boost or voltage regulation to maintain voltage stability. Simultaneously, the frequency converter 15 continuously obtains the required target DC power from the DC bus and inverts it into three-phase AC power with controllable frequency and voltage, supplying the motor of the winch 14 to ensure its smooth and efficient operation. The target DC power includes the energy transmitted to the DC bus from the battery energy storage module and the power input module. This process achieves coordinated power supply between the energy storage system and the main power source, the power input module 10, dynamically supplementing power during load surges. This avoids problems such as motor overload and voltage drops, improves the overall power response capability and operational reliability of the system, and extends the lifespan of critical equipment, demonstrating the technological advantages of intelligent energy scheduling and multi-source power supply integration.

[0043] Based on this, the energy storage system provided in this application, by introducing a frequency converter, achieves intelligent and high-precision control of the winch motor, significantly improving operating efficiency and energy saving. On the one hand, variable frequency speed regulation enables smooth start-up and speed matching, reducing mechanical shock and extending equipment life. On the other hand, it effectively recovers regenerated electrical energy during descent, greatly reducing energy loss and improving overall energy utilization. Simultaneously, the frequency converter, acting as a bridge connecting the DC bus and the motor, enhances system flexibility and stability, making energy interaction between the energy storage system and the load more efficient and controllable, providing crucial support for achieving intelligent and sustainable winch operation.

[0044] Figure 3 A schematic diagram of the architecture of a battery energy storage module provided in an embodiment of this application is shown. (Refer to...) Figure 3 As shown, the battery energy storage module 11 includes a first battery cluster 101 and a second battery cluster 102, and the first battery cluster 101 and the second battery cluster 102 are connected in parallel.

[0045] Optionally, continue to refer to Figure 3As shown, the battery energy storage module 11 also includes a first high-voltage control box 103. The first battery cluster 101 includes multiple first battery modules, which are connected in series. The positive terminal of the first first battery module is connected to the positive terminal of the battery side of the first high-voltage control box 103, and the negative terminal of the last first battery module is connected to the negative terminal of the battery side of the first high-voltage control box 103.

[0046] For example, refer to Figure 3 As shown, the first high-voltage control box 103 is as follows Figure 3 As shown in PDU01, the first high-voltage control box 103 integrates key components such as a DC contactor, a pre-charge circuit, and a current sensor. These components are used to realize functions such as on / off control, overcurrent protection, soft start, and insulation monitoring between the first battery cluster 101 and the external circuit, ensuring the safe operation of the first battery cluster 101 during charging or discharging.

[0047] For example, multiple first battery modules such as Figure 3 The PACK01, PACK02, PACK03, PACK04, and PACK05 shown are shown. PACK01 serves as the first battery module. The positive terminal of PACK01 is connected to the first high-voltage control box 103 (e.g., Figure 3 The positive terminal (B+) of the battery side of PDU01 shown is connected, and PACK05 serves as the first battery module at the end. The negative terminal of PACK05 is connected to the negative terminal (B-) of the battery side of the first high-voltage control box 103. Each first battery module has a 1P26S structure, which means a single string of 26 cells connected in series. Multiple first battery modules connected in series form a battery string with a higher total voltage, which serves as the first battery cluster 101.

[0048] Optionally, continue to refer to Figure 3 As shown, the battery energy storage module 11 also includes a second high-voltage control box 104. The second battery cluster 102 includes multiple second battery modules, which are connected in series. The positive terminal of the first second battery module is connected to the positive terminal of the battery side of the second high-voltage control box 104, and the negative terminal of the last second battery module is connected to the negative terminal of the battery side of the second high-voltage control box 104.

[0049] For example, refer to Figure 3 As shown, the second high-voltage control box 104 is as follows Figure 3 As shown in PDU02, similarly, the second high-voltage control box 104 integrates key components such as DC contactors, pre-charge circuits, and current sensors to realize functions such as on / off control, overcurrent protection, soft start, and insulation monitoring between the second battery cluster 102 and external circuits, ensuring the safe operation of the second battery cluster 102 during charging or discharging.

[0050] For example, multiple second battery modules such as Figure 3 The PACK06, PACK07, PACK08, PACK09, and PACK10 shown are shown. PACK06 serves as the first second battery module. The positive terminal of PACK06 is connected to the second high-voltage control box 104 (as shown). Figure 3 The positive terminal (B+) of the battery side of PDU02 shown is connected, and PACK10 serves as the first battery module at the end. The negative terminal of PACK10 is connected to the negative terminal (B-) of the battery side of the second high-voltage control box 104. Each second battery module has a 1P26S structure, which means a single string of 26 cells connected in series. Multiple second battery modules connected in series form a battery string with a higher total voltage, which serves as the second battery cluster 102.

[0051] Furthermore, the output terminals (P+, P-) of the first high-voltage control box 103 and the second high-voltage control box 104 are connected to the DC+ and DC- busbars in the energy storage system, respectively, thereby connecting the first battery cluster 101 and the second battery cluster 102 in parallel to the DC bus. This dual-cluster parallel structure not only improves the total capacity and power output capability of the energy storage system, but also enhances the redundancy and fault tolerance of the energy storage system. When a battery cluster fails, it can be taken out of operation by disconnecting the DC contactor of the corresponding high-voltage control box, while the other battery cluster can continue to work, ensuring that the basic functions of the energy storage system are not interrupted.

[0052] Furthermore, the entire battery energy storage module 11 adopts an air-cooled heat dissipation method, equipped with a cooling fan and a Battery Management Unit (BMU) to monitor the voltage, temperature, and other parameters of each battery module in real time, ensuring the safe operation of the battery energy storage module. Specifically, the data of each battery module is transmitted to the Battery Management Unit (BMU) via a data acquisition harness. The BMU then coordinates and controls the actions of the first high-voltage control box 103 and the second high-voltage control box 104 to achieve precise energy management and equalization control.

[0053] As one possible implementation, the first high-voltage control box 103 and the second high-voltage control box 104 include at least: a DC contactor and a battery main control management unit. Optionally, the battery main control management unit is used to detect the operating information of the first battery cluster or the second battery cluster, and determine whether the first battery cluster or the second battery cluster is operating abnormally based on the operating information. If so, it controls the DC contactor to disconnect.

[0054] For example, the first high-voltage control box 103 and the second high-voltage control box 104 serve as key electrical protection and control units in the battery energy storage module. Their core components include a DC contactor and a battery master control unit (BMU). The DC contactor is an actuator switch in the high-voltage circuit, responsible for connecting or disconnecting the electrical circuit between the first battery cluster 101 or the second battery cluster 102 and the external DC bus. The battery master control unit is used to collect and monitor the operating information of the first battery cluster 101 or the second battery cluster 102 in real time, such as voltage, current, and temperature, to ensure the safe, stable, and efficient operation of the first battery cluster 101 or the second battery cluster 102.

[0055] For example, the battery main control management unit continuously monitors the operating information of the first battery cluster 101 or the second battery cluster 102, such as whether the voltage of a single cell is too high or too low, whether the total current exceeds the limit, and whether the internal temperature of the battery pack rises abnormally. Once a parameter is found to exceed the safety threshold, such as a cell voltage reaching 4.3V or above, or a temperature exceeding 60°C, the battery cluster is determined to be in an abnormal or potential fault state. The battery main control management unit will immediately issue a control command to drive the DC contactor in the corresponding high-voltage control box to disconnect, thereby cutting off the connection between the battery cluster and the energy storage system, preventing the fault from escalating, and avoiding safety accidents such as overcurrent, short circuit, and thermal runaway.

[0056] Based on this, the energy storage system achieves real-time protection and intelligent management of the battery energy storage module through this closed-loop control mechanism, significantly improving the safety and reliability of the energy storage system.

[0057] Figure 4 A connection diagram of a second bidirectional converter provided in an embodiment of this application is shown. (Refer to...) Figure 4 As shown, the energy storage system also includes a second bidirectional converter 16. One end of the second bidirectional converter 16 is connected to the second battery cluster 102, and the other end of the second bidirectional converter 16 is connected to the AC bus. The second bidirectional converter 16 is, for example, an AC / DC converter, capable of bidirectional conversion between DC and AC power. Its operating modes include charging mode and discharging mode. The charging mode refers to the power conversion mode from AC to DC, and the discharging mode refers to the power conversion mode from DC to AC.

[0058] Optionally, continue to refer to Figure 4As shown, the energy storage system also includes a DC-side circuit breaker QF1 and an AC-side circuit breaker QF2. The first bidirectional converter 12 is connected to the DC bus via the DC-side circuit breaker QF1, and the second bidirectional converter 16 is connected to the AC bus via the AC-side circuit breaker QF2. The DC-side circuit breaker QF1 is used to quickly disconnect the circuit to prevent damage to components when an overcurrent or short circuit occurs on the DC side. The AC-side circuit breaker QF2 is used to provide overload and short-circuit fault protection for the AC output of the second bidirectional converter 16, and also supports the connection of the energy storage system to a load, allowing the AC output to be disconnected when needed.

[0059] Optionally, the second bidirectional converter 16 is used to convert the AC power output from the power input module 10 into DC power to charge the battery energy storage module 11.

[0060] For example, when the power input module 10 generates AC power, the second bidirectional converter 16 can convert the AC power generated by the power input module 10 into DC power, and perform appropriate voltage regulation through the rectifier 13 to charge the battery energy storage module 11, specifically charging the second battery cluster 102 in the battery energy storage module 11. During this process, the energy storage system is allowed to store energy while the power input module 10 is fully powered or operating, for later use.

[0061] Optionally, the second bidirectional converter 16 is also used to invert the DC power stored in the battery energy storage module 11 into AC power to supply power to the load device.

[0062] For example, the energy storage system also includes load devices, such as pump loads. When power needs to be supplied to the load devices, the second bidirectional converter 16 can invert the DC power stored in the battery energy storage module 11 into AC power, and then output the inverted AC power to the AC bus, thereby providing power support to various load devices connected to the AC bus. In this way, even if the power input module 10 is unavailable, the battery energy storage module 11 can serve as a backup power source to ensure the continuous operation of important equipment.

[0063] Based on this, the energy storage system of this application achieves efficient and flexible application of the energy storage system by introducing a second bidirectional converter 16. It can not only use cheap electricity for energy storage during low load periods, but also release the stored energy during high load or emergency situations, reducing the power supply burden and improving the reliability and stability of the entire energy storage system.

[0064] Figure 5 A schematic diagram of the architecture of a power input module according to an embodiment of this application is shown. (Refer to...) Figure 5As shown, the power input module 10 includes a main power supply 105, a backup power supply 106, and a transfer switch 107. The transfer switch 107 connects the two independent AC power supplies, the main power supply 105 and the backup power supply 106, and connects them to the AC bus.

[0065] Optionally, the main power supply 105 may be, for example, the power grid, the backup power supply 106 may be, for example, a diesel generator, and the transfer switch 107 may be, for example, an automatic transfer switch (ATS). An ATS switch is an electrical device used to automatically switch between the two power supplies, the main power supply 105 and the backup power supply 106.

[0066] Optionally, the transfer switch 107 is used to connect to the backup power supply 106 when the main power supply 105 is powered off, so as to output AC power through the backup power supply 106.

[0067] For example, when the main power supply 105 is supplying power normally, the transfer switch 107 automatically connects the main power supply 105 to provide power to the energy storage system. When the main power supply 105 fails or loses power, the transfer switch 107 will detect the voltage abnormality and automatically disconnect from the main power supply 105, quickly switching to the backup power supply 106, which will then output AC power as the power supply module to ensure the normal power supply of the energy storage system.

[0068] Optionally, the transfer switch 107 is also used to disconnect from the backup power supply 106 and reconnect to the main power supply 105 when the main power supply 105 is restored, so as to output AC power through the main power supply 105.

[0069] For example, when the main power supply 105 resumes power supply, the transfer switch 107 can automatically switch back to the main power supply 105 and disconnect the connection with the backup power supply 106, putting the backup power supply 106 into standby mode.

[0070] Based on this, the switching between the main power supply and the backup power supply is intelligently managed by the transfer switch, ensuring that even if one power supply has a power supply problem, it can be seamlessly transferred to the other power supply to continue supplying power. This reduces the power outage time of the energy storage system, protects the critical equipment in the energy storage system from the impact of power interruption, and optimizes energy utilization efficiency.

[0071] Figure 6 A schematic diagram of the architecture of another energy storage system for winch kinetic energy recovery provided in an embodiment of this application is shown. (Refer to...) Figure 6 As shown, the energy storage system also includes a braking resistor 17, which is connected to the DC bus and is used to dissipate excess electrical energy. This excess electrical energy is the excess electrical energy generated by the motor of the winch 14 during its descent operation.

[0072] Optionally, when the winch 14 is lowered under load, its motor is in generator mode, converting the gravitational potential energy and kinetic energy released during the lowering process into electrical energy, which is then fed back to the DC bus. If the battery energy storage module in the energy storage system cannot fully absorb this excess electrical energy, or if its charging capacity has reached its limit, the DC bus voltage will rise rapidly, potentially affecting the stability of the energy storage system or even damaging the equipment. To prevent excessive voltage on the DC bus, the braking resistor 17 dissipates this excess electrical energy as heat, thereby maintaining the DC bus voltage within a safe range.

[0073] It is worth noting that in this application, the braking resistor 17 is a key component to ensure the safe and reliable operation of the energy storage system. The role of the braking resistor 17 in the energy storage system is equivalent to providing an energy release mechanism. The braking resistor 17 undertakes overvoltage protection and energy balance. Especially under the conditions of frequent winch raising and lowering and large fluctuations in regenerated energy, it effectively avoids system failures caused by energy accumulation and improves the overall safety and stability of the energy storage system.

[0074] In addition, continue to refer to Figure 6 As shown, the energy storage system also includes a frequency converter module 18 and a load device 19. One end of the load device 19 is connected to one end of the frequency converter module 18, and the other end of the frequency converter module 18 is connected to the DC bus. The frequency converter module 18 is, for example, an AC / DC bidirectional frequency converter. When the load device 19 needs to be driven, the frequency converter module 18 obtains DC power from the DC bus, converts it into adjustable frequency and voltage three-phase AC power through its internal inverter circuit, and outputs it to the load device 19, enabling the load device 19 to operate according to the set operating conditions. When the load device 19 is in a power generation state, such as when a motor is decelerating under load or being lowered by gravity, the AC power it generates is rectified into DC power by the frequency converter module 18 and fed back to the DC bus, achieving energy recovery.

[0075] In summary, the energy storage system for winch kinetic energy recovery provided in this application integrates a battery energy storage module to achieve dynamic power regulation and energy recycling of the winch during operation. The energy storage system fully utilizes the gravitational potential energy and kinetic energy generated when the winch descends with a load, converting it into electrical energy and transmitting it through a DC bus to the battery energy storage module for energy recovery. When the winch is hoisting upwards under heavy load, the battery energy storage module can release electrical energy to provide additional power to the winch's motor, forming a self-charging and self-discharging closed-loop operation mode. According to this application, under heavy load conditions, the energy storage system can coordinate with the diesel generator's output power to effectively mitigate instantaneous overload and overcurrent risks, ensuring the safe and stable operation of the energy storage system. Furthermore, by recovering braking energy, it significantly reduces the thermal load impact of traditional braking resistors, reducing energy waste and improving overall energy efficiency. Moreover, the dynamic response capability of the energy storage system can compensate for insufficient power or absorb excess power in real time, making the system operation smoother and more reliable. Simultaneously, it reduces the operating load and time of the diesel generator, significantly lowering fuel consumption and exhaust emissions, achieving clean and energy-efficient operation. Furthermore, the battery energy storage module equipped in the energy storage system can serve as a low-power charging and discharging module, independently supplying power to small loads such as control units and lighting when the diesel generator stops or experiences a power outage, thereby enhancing the emergency response capabilities of small load devices. Thus, the energy storage system provided in this application not only improves energy utilization efficiency but also enhances safety and reliability.

[0076] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces; the indirect coupling or communication connection of devices or modules can be electrical, mechanical, or other forms.

[0077] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0078] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. An energy storage system for winch kinetic energy recovery, characterized by, The system comprises: a power input module, a battery energy storage module, a first bidirectional converter and a rectifier; one end of the first bidirectional converter is connected with the battery energy storage module, the other end of the first bidirectional converter is connected with a DC bus, and a motor of a winch is connected with the DC bus; one end of the rectifier is connected with the power input module through an AC bus, the other end of the rectifier is connected with the DC bus, and the rectifier is used for converting AC power input by the power input module into DC power and outputting the DC power to the DC bus; when the winch is in a descending operation condition, the motor generates electric energy which is transmitted via the DC bus and stored in the battery energy storage module; when the winch is in an ascending operation condition, the motor of the winch is supplied with power by the battery energy storage module and the power input module.

2. The system of claim 1, wherein, The system further comprises a frequency converter, one end of the frequency converter is connected with the motor of the winch, and the other end of the frequency converter is connected with the DC bus. The when the winch is in a descending operation condition, the motor generates electric energy which is transmitted via the DC bus and stored in the battery energy storage module, comprises: when the winch is in a descending operation condition, the frequency converter converts AC power generated by the motor into DC power and outputs the DC power to the DC bus, so that the voltage of the DC bus starts to rise; when the current voltage of the DC bus rises to be greater than a first threshold value, the first bidirectional converter switches to a high-window constant-voltage charging mode, obtains DC power converted from the electric energy generated by the motor from the DC bus, performs a voltage reduction operation on the DC power to obtain reduced DC power, and outputs the reduced DC power to the battery energy storage module to charge the battery energy storage module.

3. The system of claim 2, wherein, The when the winch is in an ascending operation condition, the motor of the winch is supplied with power by the battery energy storage module and the power input module, comprises: when the winch is in an ascending operation condition, the motor of the winch obtains electric energy from the DC bus, so that the voltage of the DC bus starts to drop; when the current voltage of the DC bus drops to be less than a second threshold value, the first bidirectional converter switches to a low-window constant-voltage discharging mode, and transmits the electric energy stored in the battery energy storage module to the DC bus; the frequency converter obtains target DC power from the DC bus, converts the target DC power into AC power, and outputs the AC power to the motor to supply the motor with power, and the target DC power comprises electric energy transmitted to the DC bus by the battery energy storage module and the power input module.

4. The system of claim 1, wherein, The battery energy storage module comprises a first battery cluster and a second battery cluster, and the first battery cluster and the second battery cluster are connected in parallel.

5. The system of claim 4, wherein, The battery energy storage module further comprises a first high-voltage control box. The first battery cluster comprises a plurality of first battery modules, each of the first battery modules is connected in series, and a positive electrode of a first battery module at the head is connected with a battery-side positive electrode of the first high-voltage control box, and a negative electrode of a last first battery module is connected with a battery-side negative electrode of the first high-voltage control box.

6. The system of claim 4, wherein, The battery energy storage module further comprises a second high-voltage control box. The second battery cluster comprises a plurality of second battery modules, each of the second battery modules is connected in series, and a positive electrode of a first second battery module is connected with a battery-side positive electrode of the second high-voltage control box, and a negative electrode of a last second battery module is connected with a battery-side negative electrode of the second high-voltage control box.

7. The system of claim 5 or 6, wherein, The first high-voltage control box and the second high-voltage control box at least comprise a direct-current contactor and a battery master control management unit. The battery master control management unit is configured to detect operation information of the first battery cluster or the second battery cluster, and determine whether the first battery cluster or the second battery cluster is abnormal according to the operation information, and if so, control the direct-current contactor to be disconnected, wherein the operation information comprises voltage, current and temperature.

8. The system of claim 4, wherein, The system further comprises a second bidirectional converter, one end of the second bidirectional converter is connected with the second battery cluster, and the other end of the second bidirectional converter is connected with the alternating-current bus; The second bidirectional converter is configured to convert alternating current output by the power input module into direct current to charge the battery energy storage module. The second bidirectional converter is further configured to convert direct current stored by the battery energy storage module into alternating current to supply power to a load device.

9. The system of claim 1, wherein, The power input module comprises a main power source, a backup power source and a conversion switch. The conversion switch is configured to be conductive with the backup power source when the main power source is powered off, so as to output alternating current by the backup power source. The conversion switch is further configured to be disconnected with the backup power source and be conductive with the main power source again when the main power source is powered on, so as to output alternating current by the main power source.

10. The system of claim 1, wherein, The system further comprises a braking resistor connected with the direct-current bus, and the braking resistor is configured to consume excess electric energy, wherein the excess electric energy is excess electric energy generated by a motor of the winch when the winch performs a descending operation.

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