Multi-mode hybrid power workover rig electric control system and control method thereof

Abstract

The invention discloses a multi-mode hybrid power workover rig electric control system and a control method thereof, and relates to the technical field of petroleum workover rig electric transmission control systems. Comprising a power grid interface unit, a generator interface unit, an energy storage converter, a DC-DC converter, a battery charging unit, an energy storage battery unit, a rectification unit, a winch inverter, a slurry pump inverter, a brake unit, a soft start and MCC unit, a human-computer interface and a central controller. According to the technical scheme, the problems that an existing electric workover rig is single in power source, a workover rig powered by a pure generator is low in fuel economy and high in emission, and a workover rig powered by a pure power grid and stored energy is only suitable for minor repair operation such as sand washing and pump inspection and cannot work continuously when the power grid breaks down can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical transmission control systems for petroleum well repair machines, and in particular to an electrical control system for a multi-mode hybrid power well repair machine and a control method thereof. Background Art

[0002] Since traditional vehicle-mounted workover rigs use diesel engines and mechanical transmission as the original power, they have disadvantages such as high fuel consumption, high emissions and high noise, and are gradually being replaced by electric workover rigs. At present, electric workover rigs generally use generators for centralized power supply, or use the wellhead power grid with energy storage for operation.

[0003] The use of silent generators for centralized power supply has improved fuel economy and reduced noise pollution to a certain extent, but the fuel economy is lower and the emissions are higher than those of grid operations. For high-power workover rigs, they are equipped with several power-consuming units such as electric winches, electric mud pumps, electric top drives or faucets, and solid control circulation systems. In order to ensure the economy and reliability of the operation, two sets of diesel generators are usually equipped. Only one is turned on when the load is light, and two are turned on and used in parallel when the load is heavy. However, when only one is turned on, the power fluctuation is large due to the lifting and lowering of the winch, and the grid voltage fluctuates greatly. If the power limit is not done well, the generator is likely to stall, which will affect the safety and efficiency of the operation; if two are used at the same time, the generator efficiency is low and the fuel consumption is too high, which will also increase the operating time and maintenance costs of the generator set.

[0004] The use of a small power grid in conjunction with energy storage operations can achieve "zero carbon emissions" at the well site and further reduce noise pollution from generators. The conventional solution is to use a common DC bus for all motors in the well site and drive the motors through multiple inverters. The disadvantage is that the number of motors should not be too large, and it is only suitable for minor repair operations such as sand flushing and pump inspection; and if ordinary motors are used, the high-frequency pulses output by the inverter are likely to cause problems such as motor insulation damage, rotor vibration affecting bearing life, and increased motor operating temperature. Furthermore, most well site transformers have a capacity of 30 to 50 kVA. For high-power workover rigs, the average power of the entire operation cycle far exceeds the capacity of the wellhead transformer, and pure grid operations cannot be used, which limits the application scope of pure grid-powered workover rigs, and operations cannot be completed continuously when the grid fails. Summary of the invention

[0005] In view of the above deficiencies in the prior art, the purpose of the present invention is to provide a multi-mode hybrid well repair rig electronic control system and a control method thereof, which can solve the problem that the existing electric well repair rigs have a single power source, the well repair rigs powered by pure generators have low fuel economy and high emissions, while the well repair rigs powered by pure grid plus energy storage are only suitable for minor repair operations such as sand flushing and pump inspection, and cannot continue to operate when the grid fails.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A multi-mode hybrid workover rig electronic control system includes a grid interface unit, a generator interface unit, an energy storage converter, a DC-DC converter, a battery charging unit, an energy storage battery unit, a rectifier unit, a drawworks inverter, a mud pump inverter, a brake unit, a soft start and MCC unit, a human-machine interface and a central controller.

[0007] The grid interface unit includes a measurement and protection module, an incoming line circuit breaker Q1 and an incoming line circuit breaker Q2. Since the capacity of the well site grid varies, for a small-capacity grid, the grid can be connected to the battery charging unit through the incoming line circuit breaker Q1, and for a large-capacity grid, the grid can be connected to the three-phase AC bus through the incoming line circuit breaker Q2; the generator interface unit includes a generator control module, a measurement and protection module and an incoming line circuit breaker Q3, which are used to connect a diesel generator set, a gas generator set or a hydrogen generator set; the energy storage converter includes an AC incoming line circuit breaker or a fuse-type disconnecting switch, an AC contactor, an AFE rectifier module, a DC pre-charging circuit and an disconnecting switch. An isolation transformer is configured on the AC side. The energy storage converter is also called a power conversion system PC S is a bidirectional converter, which can realize the charging and discharging of the energy storage battery, maintain the stability of the AC side power grid, and can also be independently black-started; the DC-DC converter includes a DC pre-charging circuit, a DC contactor and a fuse, which is a Buck / Boost bidirectional converter, used to maintain the voltage stability of the common DC bus, absorb energy from the energy storage battery when the inverter unit consumes energy, and store energy in the energy storage battery when the inverter unit feeds back energy; the battery charging unit is an active front-end rectifier AFE, including a voltage regulator, a power factor regulator, a current regulator and an SPWM controller; the energy storage battery unit includes an energy storage battery and a battery management system BMS, and the energy storage battery adopts lithium iron phosphate, lithium titanate or supercapacitor battery with high charge and discharge rate.

[0008] Preferably, the energy storage converter, the DC-DC converter and the DC side of the battery charging unit are all connected to the energy storage battery unit.

[0009] Preferably, the incoming circuit breaker Q2 of the grid interface unit, the generator interface unit and the energy storage converter are all connected to the three-phase AC bus of the electric control system to provide power for all electrical equipment of the workover rig.

[0010] Preferably, the rectifier unit adopts a six-pulse three-phase bridge semi-controlled rectifier module, and the three-phase AC power is output to a common DC bus after rectification; the incoming terminals of the winch inverter, mud pump inverter and brake unit are all connected to the common DC bus, and the output terminals are respectively connected to the winch variable frequency motor, mud pump variable frequency motor and brake resistor; the soft start and MCC unit includes multiple motor soft start circuits, motor direct start circuits and circuit breaker distribution circuits, which are used for well site electrical equipment and well site lighting.

[0011] Preferably, the human-machine interface adopts a touch-type industrial computer to control various electrical devices and display and record device parameters.

[0012] Preferably, the central controller adopts PLC, and the central controller interacts with all units to realize the logic control, detection protection and fault diagnosis of the electrical equipment of the electric workover rig, as well as the energy management, fire management and thermal management of the energy storage battery.

[0013] A control method using a multi-mode hybrid workover rig electronic control system comprises the following steps: S1. Turn on the UPS power supply of the control system, connect the control power supply of each unit, and the central controller establishes communication interaction with other units; S2. Set the rated capacity of the power grid and the generator in the human-machine interface. If the rated capacity of the power grid is less than or equal to the rated capacity of the battery charging unit, it is a small power grid, otherwise it is a large power grid; S3, the central controller checks the status of the power grid, energy storage and generator sets, and determines the power supply mode; S4. Select an available power mode on the human-machine interface and issue a power-on command, and the system starts supplying power; S5, the rectifier unit, inverter, brake unit, soft starter and MCC unit and other electrical equipment are switched on and powered on, and the DC-DC converter is switched on synchronously; S6. The central controller controls the on-site electrical equipment through the winch inverter, mud pump inverter, soft start and MCC unit to perform well repair operations, and automatically adjusts the winch inverter acceleration and deceleration time and power limit according to the power supply situation, which not only ensures the power supply reliability when the power capacity is small, but also meets the operating efficiency requirements when the power capacity is sufficient; S7. The central controller displays the maximum power capacity and usage percentage of the current power supply mode on the human-machine interface according to the selected power supply mode, grid rated capacity, generator rated capacity, energy storage rated capacity and load real-time power, and manages the charging and discharging of the energy storage battery unit through the energy storage inverter, DC-DC inverter and battery charging unit.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides a multi-mode hybrid workover rig electronic control system, which provides a grid interface unit, a generator interface unit and an energy storage system, and is also equipped with a rectifier unit, an inverter, a brake unit, a soft start and an MCC unit. The system architecture is simple and the structure is compact. Under the premise of using the grid as much as possible and the grid capacity is limited, the hybrid power design of the electronic control system can meet the power requirements of electric workover rigs in various power ranges, which is more green, economical and efficient.

[0015] 2. The energy storage battery unit in the present invention adopts lithium iron phosphate, lithium titanate or supercapacitor batteries with high charge and discharge rates. The energy storage inverter, DC-DC inverter and the DC side of the battery charging unit are connected to a group of energy storage battery units together. There is no need to combine with a flywheel or capacitor to achieve energy interaction between the energy storage battery and the AC bus, DC bus, and recovery of inverter feedback energy; with the battery charging unit, the capacity of the small power grid can be maximized.

[0016] 3. The central controller in the present invention integrates the PLC system for controlling the electrical equipment of the workover rig and the EMS system for managing the energy storage system, thus simplifying the system architecture and making it easy to implement the hybrid power adaptive switching strategy.

[0017] 4. The control method of the electronic control system of a multi-mode hybrid well repair rig provided by the present invention can realize four working modes: power storage, power generation storage, black start and adaptive. In particular, the adaptive mode gives priority to the use of the power grid and energy storage for operations, and can also realize the power grid, energy storage and generator being online at the same time, providing hybrid power for various electrical equipment of the power well repair rig and ensuring that the generator operates in a more economical range. It has the advantages of energy saving and emission reduction, strong adaptability, wide application range and stable and reliable power supply.

[0018] 5. The present invention provides a control method for a multi-mode hybrid power workover rig electronic control system, which automatically adjusts the acceleration and deceleration time and power limit of the winch inverter according to the power mode and power capacity, thereby ensuring the power supply reliability when the power capacity is small and meeting the operating efficiency requirements when the power capacity is sufficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 This is a structural block diagram of an electronic control system for a multi-mode hybrid workover rig; Figure 2 It is a single-line diagram of an electronic control system of a multi-mode hybrid workover rig; Figure 3 A flow chart of a control method of an electronic control system of a multi-mode hybrid workover rig; Figure 4 The present invention is a flow chart of a power adaptive control method for an electronic control system of a multi-mode hybrid workover rig.

[0021] Description of reference numerals: 1-grid interface unit, 2-generator interface unit, 3-energy storage converter, 4-DC-DC converter, 5-battery charging unit, 6-energy storage battery unit, 7-rectifier unit, 8-winch inverter, 9-mud pump inverter, 10-brake unit, 11-soft start and MCC unit, 12-human-machine interface, 13-central controller. DETAILED DESCRIPTION

[0022] The following is a detailed description of the invention by way of examples in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all of the embodiments.

[0023] Embodiment 1 like Figure 1 to Figure 2 As shown, the present invention discloses a multi-mode hybrid workover rig electronic control system, including a power grid interface unit 1, a generator interface unit 2, an energy storage converter 3, a DC-DC converter 4, a battery charging unit 5, an energy storage battery unit 6, a rectifier unit 7, a drawworks inverter 8, a mud pump inverter 9, a brake unit 10, a soft start and MCC unit 11, a human-machine interface 12 and a central controller 13.

[0024] The grid interface unit 1 includes a measurement and protection module, an incoming circuit breaker Q1 and an incoming circuit breaker Q2, which are used to connect to the grid. Since the capacity of the well site grid varies, for a small-capacity grid, the grid can be connected to the battery charging unit 5 through the incoming circuit breaker Q1; for a large-capacity grid, the grid can be connected to the three-phase AC bus through the incoming circuit breaker Q2.

[0025] The generator interface unit 2 includes a generator control module, a measurement and protection module and an incoming line circuit breaker Q3, which is used to connect a diesel generator set, a gas generator set or a hydrogen generator set. Preferably, the use of a hydrogen generator set or a gas generator set can further save energy and reduce emissions and achieve green operations; for a 550HP electric workover rig, the generator set capacity is generally configured to be around 600kVA.

[0026] The energy storage converter 3 includes an AC incoming line circuit breaker or a fuse-type disconnecting switch, an AC contactor, an AFE rectifier module, a DC pre-charging circuit and an disconnecting switch, and an isolation transformer is configured on the AC side; the energy storage converter 3, also known as the power conversion system PCS, is a bidirectional conversion device that can realize the charging and discharging of the energy storage battery, maintain the stability of the AC side power grid, and can also be independently black-started.

[0027] The DC-DC converter 4 includes a DC pre-charging circuit, a DC contactor and a fuse, and is a Buck / Boost bidirectional converter for maintaining the voltage stability of the common DC bus, absorbing energy from the energy storage battery when the inverter unit consumes energy, and storing energy in the energy storage battery when the inverter unit feeds back energy.

[0028] The battery charging unit 5 is an active front-end rectifier AFE, including a voltage regulator, a power factor regulator, a current regulator and an SPWM controller.

[0029] The energy storage battery unit 6 includes an energy storage battery and a battery management system BMS. The energy storage battery adopts lithium iron phosphate, lithium titanate or supercapacitor battery with high charge and discharge rate.

[0030] Furthermore, in this embodiment, the energy storage converter 3, the DC-DC converter 4 and the DC side of the battery charging unit 5 are all connected to the energy storage battery unit 6. For the 550HP electric well repair rig, considering that the high-power loads are mainly the winch and the mud pump, the capacity of the energy storage converter 3 is usually configured to be about 350kVA; the DC-DC converter 4 is usually configured to be about 250kW; the capacity of the battery charging unit 5 is usually configured to be 100kVA, which can make full use of the wellhead small power grid to charge the energy storage battery unit 6; the energy storage battery unit 6 is usually configured to be about 520kW. The rated capacity provided by the energy storage system can reach more than 500kW, and it can continuously output more than 1000kW of electrical energy in conjunction with the generator set.

[0031] Furthermore, in this embodiment, the incoming circuit breaker Q2 of the grid interface unit 1, the generator interface unit 2 and the energy storage converter 3 are all connected to the three-phase AC bus of the electric control system to provide power for all electrical equipment of the workover rig.

[0032] The rectifier unit 7 adopts a six-pulse three-phase bridge semi-controlled rectifier module, and the three-phase AC power is rectified and output to the common DC bus; the input ends of the winch inverter 8, the mud pump inverter 9 and the brake unit 10 are all connected to the common DC bus, and the output ends are respectively connected to the winch variable frequency motor, the mud pump variable frequency motor and the brake resistor; the soft start and MCC unit 11 includes multiple motor soft start circuits, motor direct start circuits and circuit breaker distribution circuits, which are used for well site electrical equipment and well site lighting.

[0033] The human-machine interface 12 adopts a touch-type industrial computer, which is used to control various electrical devices and display and record device parameters.

[0034] The central controller 13 uses PLC, and the central controller 13 interacts with all units to realize the logic control, detection protection and fault diagnosis of the electric workover rig electrical equipment, as well as the energy management, fire management and thermal management of the energy storage battery. The central controller 13 integrates the workover rig electrical equipment control PLC system and the energy storage system energy management system EMS, simplifies the system architecture, and facilitates the implementation of hybrid power adaptive switching strategy.

[0035] Embodiment 2 like Figure 3 to Figure 4 As shown, the present invention also discloses a control method using a multi-mode hybrid workover rig electronic control system, comprising the following steps: S1, turn on the control system UPS power supply, connect the control power supply of each unit, and the central controller 13 establishes communication interaction with other units; S2. Set the rated capacity of the power grid and the generator respectively on the human-machine interface 12. If the rated capacity of the power grid is less than or equal to the rated capacity of the battery charging unit 5, it is a small power grid, otherwise it is a large power grid; S3, the central controller 13 checks the status of the power grid, energy storage and generator set, and determines the power supply mode; S4, select an available power mode on the human-machine interface 12, and issue a power-on command, and the system starts supplying power; S5, the rectifier unit 7, the inverter, the brake unit 10, the soft starter and the MCC unit 11 and other electrical equipment are switched on and powered on, and the DC-DC converter 4 is switched on synchronously; S6, the central controller 13 controls the on-site electrical equipment to perform well repair operations through the winch inverter 8, the mud pump inverter 9 and the soft start and MCC unit 11, and automatically adjusts the acceleration and deceleration time and power limit of the winch inverter according to the power supply situation, which not only ensures the power supply reliability when the power supply capacity is small, but also meets the operating efficiency requirements when the power supply capacity is sufficient; S7, the central controller 13 displays the maximum power capacity and usage percentage of the current power supply mode on the human-machine interface 12 according to the selected power supply mode, grid rated capacity, generator rated capacity, energy storage rated capacity and load real-time power, and manages the charging and discharging of the energy storage battery unit 6 through the energy storage inverter 3, DC-DC inverter 4 and battery charging unit 5.

[0036] Further, in this embodiment, S3 includes the following steps: a) If the grid parameters are normal, the power storage mode is available, otherwise the power storage mode is disabled; b) If the generator has no faults, the power generation and storage mode is available, otherwise the power generation and storage mode is disabled; c) If the energy storage is normal and the energy storage battery SOC ≥ 20%, the black start mode is available, otherwise it is disabled; d) If at least one of the three modes, power storage, generation storage and black start, is available, the adaptive mode is available. If all are unavailable, the adaptive mode is disabled.

[0037] Further, in this embodiment, the S4 includes the following steps: S401, power supply in power storage mode: a) If it is a small power grid and the energy storage is normal (the energy storage converter 3, the battery charging unit 5 and the energy storage battery unit 6 are all normal), the incoming line circuit breaker Q1 of the grid interface unit 1 is closed, connecting the grid to the battery charging unit 5 to charge the energy storage battery; the energy storage converter 3 is online to build a three-phase AC power grid; according to the power supply capacity of the energy storage system, the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the energy storage system; b) If it is a small power grid and the energy storage fails (the energy storage converter 3 or the battery charging unit 5 or the energy storage battery unit 6 fails), an alarm is issued on the human-machine interface 12, and the incoming line circuit breaker Q2 of the power grid interface unit 1 is closed, connecting the power grid to the three-phase AC busbar, which is only used for small loads such as air conditioning and lighting; c) If it is a large power grid and the energy storage is normal (the energy storage converter 3 and the energy storage battery unit 6 are both normal), the incoming line circuit breaker Q2 of the grid interface unit 1 is closed, the grid is connected to the three-phase AC bus, the energy storage converter 3 is connected to the grid, and the central controller 13 controls the energy storage converter 3 to manage the charge and discharge of the energy storage battery unit 6 according to the load size, and limits the power of the corresponding electrical equipment to ensure that the load is within the preset rated total capacity of the grid and energy storage system; d) If it is a large power grid, and there is an energy storage failure (the energy storage converter 3 or the energy storage battery unit 6 is faulty), an alarm is issued on the human-machine interface 12, and the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the power grid.

[0038] S402, power supply in generation and storage mode: a) After the generator is automatically started, the incoming circuit breaker Q3 of the generator interface unit 2 is closed, connecting the generator power supply to the three-phase AC bus; b) If the energy storage is normal, the energy storage converter 3 is connected to the grid, and the central controller 13 controls the energy storage converter 3 to manage the charge and discharge of the energy storage battery unit 6 according to the load size, so as to ensure that the generator set operates in a relatively economical range; c) If the energy storage fails, an alarm is issued on the human-machine interface 12, and the central controller 13 limits the power of the corresponding electrical equipment according to the preset generator capacity to ensure that the load is within the rated capacity of the generator.

[0039] S403, black start mode power supply: a) Energy storage converter 3 is put online to build a three-phase AC power grid; b) According to the rated capacity of the energy storage system, the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the energy storage system; c) If the energy storage battery SOC is less than 10%, an alarm is issued on the human-machine interface 12, and the energy storage converter 3 and DCP shut down and output offline.

[0040] S404, Adaptive mode power supply: a) If the grid parameters are normal and it is a small grid, and the energy storage is normal (the energy storage converter 3, the battery charging unit 5 and the energy storage battery unit 6 are all normal), the incoming circuit breaker Q1 of the grid interface unit 1 is closed, the grid is connected to the battery charging unit 5, the energy storage converter 3 is online, and a three-phase AC grid is constructed; according to the power supply capacity of the energy storage system, the central controller 13 determines whether to trigger the power limit according to the real-time load size, and ensures that the load is within the rated capacity of the energy storage system; if the power limit is triggered or the SOC of the energy storage battery is lower than 20%, the generator set is started to be synchronously connected to the grid, and the incoming circuit breaker Q3 of the generator interface unit 2 is closed; if the load enters the low power stage (the capacity of the electric storage mode is sufficient), and the SOC of the energy storage battery is higher than 85%, the generator is opened and shut down after the load is transferred, and the power grid and energy storage provide power; if the generator fails, an alarm is issued on the human-machine interface 12, and the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the energy storage system; b) If the grid parameters are normal and it is a small grid, but the energy storage fails, the incoming circuit breaker Q2 of the grid interface unit 1 is closed (if there is a generator or energy storage online, it will be synchronized first and then closed), connecting the grid to the AC bus, and then starting the generator to synchronize and connect to the grid, the incoming circuit breaker Q3 of the generator interface unit 2 is closed, and the grid and the generator set jointly provide power for all electrical equipment; if the power limit is triggered, an alarm is issued on the human-machine interface 12, and the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the energy storage system; if the generator fails, an alarm is issued on the human-machine interface 12, and the small grid is only used for small loads such as air conditioning and lighting; c) If the grid parameters are normal and it is a large grid, and the energy storage is normal (the energy storage converter 3 and the energy storage battery unit 6 are both normal), the incoming line circuit breaker Q2 of the grid interface unit 1 is closed (if there is a generator or energy storage online, it will be synchronized first and then closed), connecting the grid to the AC bus; the energy storage converter 3 is synchronized and connected to the grid online; if the power limit is triggered or the SOC of the energy storage battery is lower than 20%, an alarm is issued on the human-machine interface 12, and the central controller 13 limits the power of the corresponding electrical equipment to ensure that the load is within the rated capacity of the energy storage system; the generator is turned on to be synchronously connected to the grid, and the incoming line circuit breaker Q3 of the generator interface unit 2 is closed, and the grid, energy storage and generator jointly provide power for all electrical equipment; if the load enters the low power stage (the capacity of the electric storage mode is sufficient), and the SOC of the energy storage battery is higher than 85%, the generator is opened and shut down after the load is transferred, and the grid and energy storage provide power; d) If the grid parameters are abnormal but the generator is in normal condition, the system will enter S402 generation and storage mode to supply power; e) If the grid parameters are abnormal and the generator fails, the power supply will enter S403 black start mode; f) Repeat steps a) to e) according to the status of the power grid, generator and energy storage.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and application concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-mode hybrid workover rig electronic control system, characterized in that: It includes grid interface unit, generator interface unit, energy storage converter, DC-DC converter, battery charging unit, energy storage battery unit, rectifier unit, winch inverter, mud pump inverter, brake unit, soft start and MCC unit, human-machine interface and central controller; The grid interface unit includes a measurement and protection module, an incoming line circuit breaker Q1 and an incoming line circuit breaker Q2; The generator interface unit includes a generator control module, a measurement and protection module and an incoming line circuit breaker Q3; The energy storage converter includes an AC incoming line circuit breaker or a fuse-type isolating switch, an AC contactor, an AFE rectifier module, a DC pre-charging circuit and an isolating switch, and an isolation transformer is configured on the AC side; The DC-DC converter includes a DC pre-charging circuit, a DC contactor and a fuse; The battery charging unit includes a voltage regulator, a power factor regulator, a current regulator and an SPWM controller; The energy storage battery unit includes an energy storage battery and a battery management system BMS.

2. A multi-mode hybrid workover rig electronic control system as claimed in claim 1, characterized in that: The energy storage converter, the DC-DC converter and the DC side of the battery charging unit are all connected to the energy storage battery unit.

3. A multi-mode hybrid workover rig electronic control system as claimed in claim 2, characterized in that: The incoming circuit breaker Q2 of the grid interface unit, the generator interface unit and the energy storage converter are all connected to the three-phase AC busbar of the electric control system.

4. A multi-mode hybrid workover rig electronic control system as claimed in claim 3, characterized in that: The rectifier unit adopts a six-pulse three-phase bridge semi-controlled rectifier module, and the three-phase AC power is rectified and output to a common DC bus; the incoming terminals of the winch inverter, mud pump inverter and brake unit are all connected to the common DC bus, and the output terminals are respectively connected to the winch variable frequency motor, mud pump variable frequency motor and brake resistor; the soft start and MCC unit includes multiple motor soft start circuits, motor direct start circuits and circuit breaker power distribution circuits.

5. A multi-mode hybrid workover rig electronic control system as claimed in claim 4, characterized in that: The human-machine interface adopts a touch-type industrial computer.

6. A multi-mode hybrid workover rig electronic control system as claimed in claim 5, characterized in that: The central controller adopts PLC, and the central controller interacts with all units to realize the logic control, detection protection and fault diagnosis of the electrical equipment of the electric workover rig, as well as the energy management, fire management and thermal management of the energy storage battery.

7. A control method using the electronic control system as claimed in claim 6, characterized in that: The following steps are involved: S1. Turn on the UPS power supply of the control system, connect the control power supply of each unit, and the central controller establishes communication interaction with other units; S2. Set the rated capacity of the power grid and the generator in the human-machine interface. If the rated capacity of the power grid is less than or equal to the rated capacity of the battery charging unit, it is a small power grid, otherwise it is a large power grid; S3, the central controller checks the status of the power grid, energy storage and generator sets, and determines the power supply mode; S4. Select an available power mode on the human-machine interface and issue a power-on command, and the system starts supplying power; S5, the rectifier unit, inverter, brake unit, soft starter and MCC unit are switched on and powered on, and the DC-DC converter is switched on synchronously; S6, the central controller controls the on-site electrical equipment to perform well repair operations through the winch inverter, mud pump inverter, soft start and MCC unit, and automatically adjusts the winch inverter acceleration and deceleration time and power limit according to the power supply situation; S7. The central controller displays the maximum power capacity and usage percentage of the current power supply mode on the human-machine interface according to the selected power supply mode, grid rated capacity, generator rated capacity, energy storage rated capacity and load real-time power, and manages the charging and discharging of the energy storage battery unit through the energy storage inverter, DC-DC inverter and battery charging unit.

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