Electric workover rig battery charging and discharging control method and system

Abstract

The invention discloses an electric workover rig battery charging and discharging control method and system, and relates to the field of battery charging and discharging strategies, and the battery charging and discharging control method comprises a charging control method and a discharging control method. The charging control method comprises the following steps: detecting the voltage of a battery to be charged, entering a pre-charging stage when the voltage is lower than a first voltage threshold value, entering a constant-current charging stage when the voltage reaches a second voltage threshold value, and entering a constant-voltage charging stage when the voltage reaches a third voltage threshold value, the charging is finished until the current of the battery to be charged reaches a current threshold value; the discharge control method comprises the following steps: detecting a single cell voltage and a total cell voltage in real time in a battery discharge process, when the single cell voltage is less than or equal to a single cell voltage threshold, prompting that a single cell is under-voltage, and when the total cell voltage is less than or equal to a total cell voltage small threshold, prompting that the total cell voltage is under-voltage. Safe charging of the battery can be guaranteed, and the service life is prolonged.

Description

Technical Field

[0001] The present application relates to the field of battery charging and discharging strategies, and in particular to a battery charging and discharging control method and system for an electric well repair machine. Background Art

[0002] As the oil and gas industry pays more attention to environmental protection and sustainable development, electric workover rigs have gradually become mainstream equipment. Compared with traditional diesel-driven workover rigs, electric workover rigs can reduce emissions and improve energy efficiency. The global energy structure is transforming towards clean and renewable energy, and the advancement of battery technology makes electric drive systems more feasible in workover rigs. As an energy storage device, the performance of batteries directly affects the operating efficiency and endurance of electric workover rigs. The rapid development of new battery technologies such as lithium-ion batteries and solid-state batteries has improved the energy density, charging and discharging efficiency, and safety of batteries, laying the foundation for the application of electric workover rigs. The battery management system is an important part of ensuring the safe and efficient operation of batteries.

[0003] When the battery is charging, the movement of electrons inside the battery is faster than when it is discharging. In order to quickly charge the battery, the charger manufacturer has greatly increased the output power of the charger. High current and high voltage will indeed charge faster than low current, but the faster movement of electrons causes the temperature inside the battery to rise faster and higher, resulting in reduced battery safety and service life. Summary of the invention

[0004] Based on this, the present application provides a method and system for controlling battery charging and discharging of an electric well repair machine.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for controlling battery charging and discharging of an electric workover machine, comprising:

[0007] Charging control method and discharging control method;

[0008] The charging control method comprises:

[0009] Detecting the voltage of the battery to be charged, when the voltage is lower than a first voltage threshold, entering a pre-charging stage, when the voltage reaches a second voltage threshold, entering a constant current charging stage, when the voltage reaches a third voltage threshold, entering a constant voltage charging stage, until the current of the battery to be charged reaches a current threshold, charging ends;

[0010] The discharge control method comprises:

[0011] During the battery discharge process, the single cell voltage and the overall cell voltage are detected in real time. When the single cell voltage is less than or equal to the single cell voltage threshold, it prompts that the single cell is under-voltage. When the overall cell voltage is less than or equal to the overall cell voltage small threshold, it prompts that the overall cell voltage is under-voltage.

[0012] In a second aspect, the present application provides a battery charge and discharge control system for an electric workover machine, comprising: a charge control module and a discharge control module;

[0013] The charging control module is used to detect the voltage of the battery to be charged, and when the voltage is lower than a first voltage threshold, enter the pre-charging stage, when the voltage reaches a second voltage threshold, enter the constant current charging stage, and when the voltage reaches a third voltage threshold, enter the constant voltage charging stage, until the current of the battery to be charged reaches the current threshold, the charging ends;

[0014] The discharge control module is used to detect the single cell voltage and the overall cell voltage in real time during the battery discharge process. When the single cell voltage is less than or equal to the single cell voltage threshold, it prompts that the single cell is under-voltage; when the overall cell voltage is less than or equal to the overall cell voltage small threshold, it prompts that the overall cell voltage is under-voltage.

[0015] According to the specific embodiments provided in this application, this application has the following technical effects:

[0016] The present application provides a method and system for controlling the charging and discharging of batteries of an electric well repair machine. The charging process of the battery is divided into four stages: pre-charging, constant current charging, constant voltage charging, and charging completion. During the charging control process, the battery can be safely charged by setting the charging current and voltage thresholds. During the discharge control process, the single cell voltage and the overall cell voltage are constantly changing according to the external load. When the single cell voltage and the overall cell voltage detected in real time are less than or equal to the threshold, the corresponding alarm item is triggered, thereby protecting the battery safety and improving the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A flowchart of a method for controlling battery charging and discharging of an electric workover rig provided in one embodiment of the present application. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] In an exemplary embodiment, Figure 1 As shown, a method for controlling battery charge and discharge of an electric well repair machine is provided, and the method for controlling battery charge and discharge includes: a charging control method and a discharging control method.

[0022] The charging control method includes: detecting the voltage of the battery to be charged, entering a pre-charging stage when the voltage is lower than a first voltage threshold, entering a constant current charging stage when the voltage reaches a second voltage threshold, and entering a constant voltage charging stage when the voltage reaches a third voltage threshold, until the charging ends when the current of the battery to be charged reaches a current threshold.

[0023] Specifically, the battery charging process can be divided into four stages: pre-charging, constant current charging, constant voltage charging and charging end.

[0024] The battery charging method is voltage-limited constant current, which is controlled by battery data acquisition. The charging control method is as follows:

[0025] First detect the voltage of the battery to be charged. If the voltage is lower than the first voltage threshold of 2.4V (460.8V), pre-charge is required first. The charging current is 1 / 10 of the continuous charging current. After the voltage rises to the second voltage threshold of 2.4V (460.8V), it enters the constant current charging stage. The constant current charging stage is: constant current charging with a continuous charging current. When the battery voltage rises to the third voltage threshold of 3.0V (576V), it is changed to constant voltage charging, and the charging voltage is maintained at 3.2V (614.4V). At this time, the charging current gradually decreases. When the current drops to the current threshold (1 / 10 of the charging current), the charging is completed.

[0026] Stage 1: Pre-charge - In the pre-charge stage, the fully discharged battery is pre-charged (recovery charge). Pre-charge is used when the voltage is lower than about 2.4V (460.8V). The charging current in the pre-charge stage is one tenth of the continuous charging current, that is, 0.1c (for example, if the charging current of the constant charge is 1A, the charging current of the pre-charge is 100mA).

[0027] Phase 2: Constant current charging - When the voltage rises to the second voltage threshold, the charging current is increased for constant current charging. The charging current of constant current charging is between 0.2C and 1.0C. The battery voltage gradually increases with the constant current charging process. Generally, the voltage set for a single battery is 2.8-3.15V (537.6V-604.8V).

[0028] Phase 3: Constant voltage charging - When the battery voltage rises to the third voltage threshold, the constant current charging ends and the constant voltage charging phase begins. As the charging process continues, the charging current slowly decreases from the maximum value. When it decreases to 0.01C, the charging is considered terminated. (C is a method of expressing the nominal capacity of the battery against the current. For example, if the battery has a capacity of 1000mAh, 1C means the charging current is 1000mA.)

[0029] Stage 4: Charging end: using the minimum charging current to judge. Monitor the charging current during the constant voltage charging stage and terminate the charging when the charging current decreases to the range of 0.02C to 0.07C.

[0030] In order to ensure the safety and service life of the battery, the present application controls the charging process of the battery and inputs the charging voltage and charging current in a stable manner to ensure the safety performance of the battery.

[0031] The basic requirements for battery charging are specific charging current and charging voltage to ensure safe battery charging. Other charging auxiliary functions are added to improve battery life and simplify the operation of the charger, including trickle charging for over-discharged batteries, battery voltage detection, input current limiting, shutting down the charger after charging is completed, and automatically starting charging after partial battery discharge.

[0032] The discharge control method includes: real-time detection of single cell voltage and overall cell voltage during battery discharge; when the single cell voltage is less than or equal to the single cell voltage threshold, prompting a single cell undervoltage; when the overall cell voltage is less than or equal to the overall cell voltage small threshold, prompting an overall cell voltage undervoltage.

[0033] Specifically, the single cell voltage and the overall cell voltage are constantly changing according to the external load, and when the real-time value is less than or equal to the set threshold range, the corresponding alarm item is triggered.

[0034] For example: the battery has 192 strings of single cells, the average single cell voltage is 2.8 volts, and the overall cell voltage is 192*2.8=537.6 volts. When the external load is consuming power, when the voltage of one single cell drops to 2.4 volts, the real-time value is compared with the single cell voltage threshold, indicating that the single cell is undervoltage; when the external load continues to consume power, when the voltage of 10% of the single cells in the 192 strings continues to drop to 2.4 volts, the overall cell voltage real-time value is compared with the overall cell voltage threshold, indicating that the overall cell voltage is undervoltage, and the output is cut off and the main circuit is cut off, thereby avoiding over-discharge of the battery.

[0035] The control of the discharge process is to ensure the service life and safety of the battery. This application also adds over-discharge alarm, single cell undervoltage alarm, total voltage undervoltage alarm, cell high temperature alarm, pulse discharge current over-limit alarm, etc., and sets thresholds for each item. The collected real-time value is compared with the threshold, and the corresponding processing is made after judgment. Each processing is to ensure the safety and service life of the battery.

[0036] The electric workover machine battery charge and discharge control method provided in the present application also includes: detecting the temperature of the battery, and setting a high temperature alarm threshold and a low temperature alarm threshold to ensure that the battery operates in a safe temperature environment.

[0037] Under safe conditions, the appropriate temperature can allow the battery to maximize the discharge potential of the battery pack. For safety reasons, it is necessary to avoid the battery working in extreme conditions, or in extreme conditions, ensure the safety of the system as much as possible to prevent or reduce losses caused by fire or explosion. Warm the battery when it is very cold, and cool it down when it is very hot. From a scenario perspective, there are mainly two scenarios: charging and discharging. If charging in a cold area when the temperature is particularly low and there are no auxiliary facilities, the car will not be able to charge. At this time, a preheating module needs to be added to the battery, and charging can be carried out after the physical temperature of the battery rises. If charging under high temperature conditions in tropical areas, the cooling system should also be started for the battery temperature to cool the battery.

[0038] The electric well repair machine battery charge and discharge control method provided in the present application also includes: setting the maximum charging current and discharging current to protect the battery from damage caused by sudden current.

[0039] The electric well repair machine battery charge and discharge control method provided in the present application also includes: performing balanced management on single-cell batteries to ensure balanced charge and discharge of each single-cell battery and extend the overall service life of the battery.

[0040] The balancing circuit is to eliminate the inconsistency of single-cell batteries during use. For example, two adjacent single-cell batteries: one with a voltage of 3.6 volts and the other with a voltage of 3.4 volts. Let the single-cell battery with a voltage of 3.6 volts discharge to the single-cell battery with a voltage of 3.4 volts, so that its single-cell voltage is 3.5 volts, and then start charging again. When there is a voltage difference between the two single-cell batteries. The charging and discharging between cells is carried out according to the same working principle to achieve the purpose of balancing. According to the short board effect of the wooden barrel, the single-cell battery with the worst performance reaches the cut-off condition first during charging and discharging, and some energy of other single-cell batteries has not been released, resulting in battery waste. In order to make up for these losses, a balancing circuit is used to transfer the single-cell battery with more energy to the single-cell battery with less energy.

[0041] Based on the same inventive concept, the embodiment of the present application also provides a system for implementing the above-mentioned electric workover machine battery charge and discharge control method. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more electric workover machine battery charge and discharge control system embodiments provided below can refer to the above-mentioned limitations on the electric workover machine battery charge and discharge control method, and will not be repeated here.

[0042] In an exemplary embodiment, a battery charge and discharge control system for an electric workover machine is provided, comprising: a charge control module and a discharge control module.

[0043] The charging control module is used to detect the voltage of the battery to be charged, and when the voltage is lower than a first voltage threshold, enter the pre-charging stage, when the voltage reaches a second voltage threshold, enter the constant current charging stage, and when the voltage reaches a third voltage threshold, enter the constant voltage charging stage, until the current of the battery to be charged reaches the current threshold, the charging ends;

[0044] The discharge control module is used to detect the single cell voltage and the overall cell voltage in real time during the battery discharge process. When the single cell voltage is less than or equal to the single cell voltage threshold, it prompts that the single cell is under-voltage; when the overall cell voltage is less than or equal to the overall cell voltage small threshold, it prompts that the overall cell voltage is under-voltage.

[0045] The electric workover machine battery charge and discharge control system provided in the present application also includes: a temperature detection and threshold setting module, which is used to detect the temperature of the battery and set a high temperature alarm threshold and a low temperature alarm threshold.

[0046] The battery charging and discharging control system for the electric well repair machine provided in the present application also includes: a current setting module for setting the maximum charging current and discharging current.

[0047] The battery charge and discharge control system for the electric workover rig provided in the present application also includes: a balancing management module for performing balancing management on single-cell batteries.

[0048] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0049] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for controlling battery charging and discharging of an electric workover machine, characterized in that: include: Charging control method and discharging control method; The charging control method comprises: Detecting the voltage of the battery to be charged, when the voltage is lower than a first voltage threshold, entering a pre-charging stage, when the voltage reaches a second voltage threshold, entering a constant current charging stage, when the voltage reaches a third voltage threshold, entering a constant voltage charging stage, until the current of the battery to be charged reaches a current threshold, charging ends; The discharge control method comprises: During the battery discharge process, the single cell voltage and the overall cell voltage are detected in real time. When the single cell voltage is less than or equal to the single cell voltage threshold, it prompts that the single cell is under-voltage. When the overall cell voltage is less than or equal to the overall cell voltage small threshold, it prompts that the overall cell voltage is under-voltage.

2. The method for controlling battery charge and discharge of an electric workover rig according to claim 1, characterized in that: The charging current in the pre-charging stage is 1 / 10 of the continuous charging current.

3. The method for controlling battery charge and discharge of an electric workover rig according to claim 1, characterized in that: In the constant current charging stage, constant current charging is performed with a continuous charging current.

4. The method for controlling battery charge and discharge of an electric workover rig according to claim 1, characterized in that: Also includes: Detect the battery temperature and set high temperature alarm threshold and low temperature alarm threshold.

5. The method for controlling battery charge and discharge of an electric workover rig according to claim 1, characterized in that: Also includes: Set the maximum charge current and discharge current.

6. The method for controlling battery charge and discharge of an electric workover rig according to claim 1, characterized in that: Also includes: Perform balanced management on single-cell batteries.

7. An electric workover rig battery charge and discharge control system, characterized in that: include: A charging control module and a discharging control module; The charging control module is used to detect the voltage of the battery to be charged, and when the voltage is lower than a first voltage threshold, enter the pre-charging stage, when the voltage reaches a second voltage threshold, enter the constant current charging stage, and when the voltage reaches a third voltage threshold, enter the constant voltage charging stage, until the current of the battery to be charged reaches the current threshold, the charging ends; The discharge control module is used to detect the single cell voltage and the overall cell voltage in real time during the battery discharge process. When the single cell voltage is less than or equal to the single cell voltage threshold, it prompts that the single cell is under-voltage; when the overall cell voltage is less than or equal to the overall cell voltage small threshold, it prompts that the overall cell voltage is under-voltage.

8. The battery charge and discharge control system for an electric workover rig according to claim 7, characterized in that: Also includes: The temperature detection and threshold setting module is used to detect the temperature of the battery and set the high temperature alarm threshold and the low temperature alarm threshold.

9. The battery charge and discharge control system for an electric workover rig according to claim 7, characterized in that: Also includes: The current setting module is used to set the maximum charging current and discharging current.

10. The battery charge and discharge control system for an electric workover rig according to claim 7, characterized in that: Also includes: The balancing management module is used to perform balancing management on single-cell batteries.

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