Diesel-storage combined power supply system and coordination control method thereof

Abstract

The invention discloses a diesel-storage combined power supply system and a coordination control method thereof, and belongs to the technical field of power system control, and the method comprises the steps: obtaining operation state data, and determining the total load power; determining a working mode according to the total load power and a logic threshold value, and distributing the total load power into generator target power and energy storage target power; when the working mode is the energy storage independent power supply mode, a prime motor is stopped, and the output voltage is kept stable by adopting a voltage rotating speed control strategy; and when the working mode is the generator independent power supply mode or the diesel-storage combined power supply mode or the energy storage charging mode, a coordination control strategy is executed, and the output voltage is kept stable through coordination control of the first path and the second path. The problem of coupling of the power and the frequency of the induction generator is effectively solved, and the frequency stability and the dynamic impact resistance of the system are improved.

Description

A diesel-storage combined power supply system and its coordinated control method Technical Field

[0001] This invention relates to the field of power system control technology, and in particular to a combined diesel and energy storage power supply system and its coordinated control method. Background Technology

[0002] In hybrid power supply systems composed of diesel generators and energy storage systems, induction generators are widely used due to their simple structure and high reliability. In particular, the dual-stator winding induction generator (DWIG), with its two independent stator windings—one outputting high-voltage AC power and the other connected to an excitation converter or energy storage system—offers flexible power regulation and energy management capabilities, making it suitable for the multi-energy coordinated operation requirements of diesel-energy storage hybrid systems. However, the inherent output characteristics of induction generators dictate that their electromagnetic torque is proportional to their slip. When the load changes, increasing the output power requires increasing the slip. In traditional control strategies, the prime mover speed is usually kept constant; in this case, an increase in slip directly causes a decrease in the generator's output frequency. Especially during transient processes with sudden load increases, the frequency may drop significantly, affecting power quality and potentially triggering low-frequency protection, leading to system instability or even power outages. Furthermore, there are significant differences in the dynamic response characteristics between the prime mover (such as a diesel prime mover) and the generator in a diesel-energy storage hybrid system. As a mechanical power source, the prime mover's speed regulation has significant inertia, with a response speed typically on the order of seconds. In contrast, the generator side uses a power electronic converter for torque control, achieving a response speed on the order of milliseconds. When the load changes rapidly, if the electromagnetic torque is increased quickly only through the electrical side without the prime mover's speed keeping up, it can easily cause instantaneous overload of the prime mover. In severe cases, this can lead to a sudden drop in speed or even engine shutdown, ultimately causing system frequency collapse.

[0003] Therefore, achieving dynamic coordination between the prime mover and the generator, while balancing frequency stability and prime mover protection, is a critical issue that urgently needs to be addressed in the control of current diesel-storage combined power supply systems. While existing technologies include control methods involving speed regulation and torque limiting, these methods often focus on improving only one aspect or rely on additional frequency regulation devices in their structure. They have not yet fundamentally solved the problem of coordinated control between power-frequency coupling and prime mover dynamic protection for induction generators without increasing system complexity. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies of the prior art and provide a diesel-storage combined power supply system and its coordinated control method, which can maintain system frequency stability and ensure the safe operation of prime mover under load fluctuations, thereby improving the dynamic performance and operational reliability of the diesel-storage combined power supply system.

[0005] In a first aspect, this application provides a coordinated control method for a diesel-storage combined power supply system. The diesel-storage combined power supply system includes a generator module and an energy storage module. The energy storage module is connected to the DC input terminal of a converter module to supply power to the converter module. The AC output terminal of the converter module is connected to the generator module to input excitation power to the generator module. The generator module includes a prime mover and a generator. The prime mover drives the rotor of the generator to rotate. The coordinated control method for the diesel-storage combined power supply system includes the following steps: acquiring operating status data and determining the total load power; determining the operating mode based on the total load power and a preset logic threshold, and allocating the total load power to the generator target power and the energy storage target power; the operating mode includes an energy storage separate power supply mode, a generator separate power supply mode, a diesel-storage combined power supply mode, and an energy storage charging mode; when the operating mode is the energy storage separate power supply mode, the prime mover is stopped, and a voltage-speed control strategy is adopted to maintain the output voltage stability; when the operating mode is the generator separate power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed, and the output voltage is maintained stable through first path and second path coordinated control.

[0006] Optionally, the operating mode is determined based on the total load power and a preset logic threshold, including: when SOC > SOC high And P load <min(P ess_max ,P start When SOC ≤ SOC, it is in energy storage independent power supply mode; when SOC ≤ SOC low or P load When the prime mover is in its optimal fuel efficiency power range and the state of charge (SOC) is within the normal range, the generator operates in standby mode; when the SOC is within the normal range and P... load When a sudden increase occurs or exceeds the optimal efficiency operating point of the prime mover, the combined diesel and energy storage power supply mode is activated; when the SOC... <SOC obj And P load <P gen_optmas When in this mode, it is in energy storage charging mode; where SOC represents the state of charge, P load P represents the total load power. ess_max P represents the maximum power that the energy storage module can safely output at any given moment. start State of Charge (SOC) indicates the generator starting power threshold. high Indicates the upper limit of the state of charge (SOC). low Indicates the lower limit of the state of charge (SOC).obj P represents the target value of the state of charge. gen_optmas This indicates the optimal efficiency operating point of the prime mover.

[0007] Optionally, the total load power can be allocated into a generator target power and an energy storage target power, including: for a separate energy storage power supply mode, when SOC > SOC high And P load <min(P ess_max ,P start When setting the generator target power P, gen = 0, target energy storage power P ess =P load When SOC > SOC high And P load <P ess_max Then set the generator target power P. gen =0, target energy storage power P ess =P load For generator-only power supply mode, set the generator target power P. gen =P load Energy storage target power P ess =0; For the combined diesel and energy storage power supply mode, when the SOC is within the normal range and P load A sudden increase or exceeding the optimal efficiency operating point P of the prime mover occurs. gen_optmas At that time, the generator target power P gen Set at the optimal efficiency operating point P of the prime mover gen_optmas That is, P gen =P gen_optmas Energy storage target power For energy storage charging mode, if SOC <SOC obj And P load <P gen_opt Then set the generator target power P gen =P load +P charge Energy storage target power Among them, P charge The preset charging power is given by SOC, which represents the state of charge. load P represents the total load power. ess_max P represents the maximum power that the energy storage module can safely output at any given moment. start State of Charge (SOC) indicates the generator starting power threshold. high Indicates the upper limit of the state of charge (SOC). low Indicates the lower limit of the state of charge (SOC). obj P represents the target value of the state of charge. gen_optmas This indicates the optimal efficiency operating point of the prime mover.

[0008] Optionally, when the operating mode is the generator-only power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed to maintain output voltage stability through coordinated control of the first path and the second path. This includes: when the operating mode is the generator-only power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed to perform coordinated control through the first path and the second path; the first path includes: determining the reference torque based on the generator target power, calculating the target slip angular frequency required to generate the reference torque based on the torque-slip characteristics of the induction generator, and superimposing the grid target synchronization angular frequency with the target slip angular frequency to obtain the prime mover speed command; the second path includes: setting the initial torque command based on the generator target power or voltage loop output, calculating the deviation between the measured speed of the prime mover and the prime mover speed command, correcting the initial torque command through a torque limiting circuit to obtain the final torque command; and controlling the prime mover speed governor and the generator controller according to the prime mover speed command and the final torque command respectively to achieve output voltage stability.

[0009] Optionally, the prime mover speed command The expression is: in, , representing the slip coefficient; The reference torque; This is the torque coefficient.

[0010] Optionally, the torque limiting circuit includes a dynamic saturator, which is related to the measured speed of the prime mover. The function, when the measured speed of the prime mover is detected. Less than the prime mover speed command And the measured rate of change of rotational speed Set the final torque command when it is not less than zero. Less than or equal to the maximum residual torque that the prime mover can provide.

[0011] Optionally, the maximum residual torque that the prime mover can provide is the dynamic torque limit value. The expression is: in, This indicates the maximum torque at the current measured speed of the prime mover. Acceleration torque reserved within the maximum torque.

[0012] Optionally, the coordinated control method of the diesel-storage combined power supply system is integrated into a computer device, the computer device including one or more processors; a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the coordinated control method of the diesel-storage combined power supply system.

[0013] Secondly, this application also provides a combined diesel and energy storage power supply system, using the coordinated control method for the combined diesel and energy storage power supply system as described in the first aspect, comprising: a generator module, an energy storage module, and a central control module. The central control module collects the measured rotational speed of the generator module and the charge state of the energy storage module, and sends rotational speed commands and control commands to the generator module and the energy storage module, respectively. The generator module receives the rotational speed commands output by the central control module and generates electricity. The energy storage module is connected to the DC input terminal of the converter module to provide DC power to the converter module. The AC output terminal of the converter module is connected to the generator module to input excitation energy to the generator module.

[0014] Optionally, the generator module includes a prime mover, a speed governor, and a generator. The speed governor receives speed commands from the central control module and controls the mechanical torque output by the prime mover by adjusting the fuel supply or throttle opening. The prime mover drives the rotor of the generator to rotate.

[0015] This application provides a combined diesel and energy storage power supply system and its coordinated control method. By applying different control strategies to four typical operating conditions—energy storage powered alone, generator powered alone, combined diesel and energy storage powered, and energy storage charging—optimal energy allocation is achieved under different load conditions. When energy storage is powered alone, controlling the prime mover to shut down effectively reduces no-load losses, fuel consumption, and noise emissions, improving the system's quiet operation capability and environmental benefits. In other modes, through the coordinated control of the first and second paths, it can quickly respond to load fluctuations, ensuring high stability of the output voltage and enhancing the system's adaptability to dynamic loads. This method, through refined mode management and multi-path coordinated control, significantly improves operating efficiency and extends equipment life while ensuring power supply reliability. It effectively solves the coupling problem between induction generator power and frequency, improving the system's frequency stability and dynamic shock resistance.

[0016] To make the above-mentioned features and advantages of the invention more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a schematic diagram of the combined diesel and energy storage power supply system provided in one embodiment of this application.

[0019] Figure 2 is a flowchart of a coordinated control method for a combined diesel and energy storage power supply system provided in one embodiment of this application.

[0020] Figure 3 is a flowchart of the first path and second path coordination control in the coordination control method of the diesel-storage combined power supply system provided in one embodiment of this application.

[0021] Figure 4 is a schematic diagram of the output frequency waveform when the load changes abruptly. Detailed Implementation

[0022] To make the objectives and technical solutions 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. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of this application without creative effort are within the scope of protection of this application.

[0023] In one embodiment, referring to Figure 1, this application provides a combined diesel and energy storage power supply system, which may include: a generator module 1, a converter module 2, a central control module 3, and an energy storage module 4. The central control module 3 collects the measured speed of the generator module 1. The energy storage module 4 is in its state of charge (SOC) and sends a speed command to the generator module 1. The generator module 1 sends control commands to the conversion module 2; the generator module 1 receives the speed commands output by the central control module 3. The energy storage module 4 is connected to the DC input terminal of the conversion module 2 to provide DC power to the conversion module 2; the AC output terminal of the conversion module 2 is connected to the generator module 1 to input excitation energy to the generator module 1.

[0024] As an example, generator module 1 may include prime mover 11, speed governor 12, and generator 13, wherein speed governor 12 receives speed commands from central control module 3. The mechanical torque output of the prime mover 11 is controlled by adjusting the fuel supply or throttle opening; the prime mover 11 converts the chemical energy of the fuel into mechanical energy, driving the rotor of the generator 13 to rotate.

[0025] As an example, prime mover 11 can be a diesel prime mover.

[0026] As an example, generator 13 can be a dual-stator induction generator (DWIG) with two sets of physically and electrically isolated windings on the stator side, which can output voltages of different levels.

[0027] As an example, the generator 13 includes a first stator winding 131, a second stator winding 132, and a rotor 133. The first stator winding 131, the second stator winding 132, and the rotor 133 are electromagnetically coupled to each other. The first stator winding 131 is connected to the conversion module 2, and the rotor 133 is rigidly connected to the mechanical input end of the prime mover 11.

[0028] As an example, the first stator winding 131 can be a low-voltage control winding, the second stator winding 132 can be a high-voltage power winding, and the rotor 133 can be a squirrel-cage rotor.

[0029] As an example, the second stator winding 132 is directly connected to the load or high-voltage bus to supply power to the external load; the energy storage module 4 injects or extracts active power into the second stator winding 132 through the first stator winding 131 to achieve joint power supply or absorb excess power. The dual-stator induction generator realizes electromechanical energy conversion and supports multiple power supply modes.

[0030] As an example, the generator 13 converts the mechanical energy input from the prime mover 11 into electrical energy and outputs power through the first stator winding 131 and the second stator winding 132; the rotor 133 is responsible for coupling with the magnetic field of the two stator windings to realize electromagnetic energy conversion, while using the dual winding structure to improve the flexibility of the power generation system.

[0031] As an example, the power output shaft of the prime mover 11 is rigidly connected to the mechanical input end of the generator 13, providing mechanical energy to drive the generator 13.

[0032] As an example, part of the electrical energy generated by generator 13 can be rectified by conversion module 2 through first stator winding 131 to charge energy storage module 4.

[0033] As an example, the conversion module 2 includes a DC input terminal and an AC output terminal. The energy storage module 4 is connected to the DC input terminal of the conversion module 2, and the power regulation of the generator module 1 is realized through the conversion module 2. The AC output terminal of the conversion module 2 is connected to the first stator winding 131 of the generator 13, and the output drive signal cooperates with the first stator winding 131 to realize grid-connected pre-synchronization and power regulation.

[0034] As an example, conversion module 2 can be a power conversion system (PCS).

[0035] As an example, energy storage module 4 may include a battery pack.

[0036] As an example, the energy storage module 4 transmits electrical energy to the generator 13 through the conversion module 2, providing excitation support and instantaneous power compensation for the generator 13. In the energy storage-only power supply mode, the generator 13 is driven to operate as a rotary transformer; in the generator-only power supply mode, the diesel-energy storage combined power supply mode, or the energy storage charging mode, the energy storage module 4 and the generator 13 work together to regulate power output. When the load suddenly increases, before the prime mover 11 has had time to increase its speed and power, the energy storage module 4 outputs the shortfall power through the conversion module 2 within milliseconds to maintain system power balance and frequency stability.

[0037] As an example, the central control module 3 is communicatively connected to the speed governor 12 and generator 13 of the generator module 1 and the conversion module 2 of the energy storage module 4.

[0038] As an example, the central control module 3 may include a central controller 31 and a generator controller 32, with the central controller 31 sending torque commands to the generator controller 32. The generator controller 32 will send torque commands. The commands are converted into control commands by the conversion module 2, which then controls the excitation of the generator 13. The central controller 31 collects the state of charge (SOC) of the battery pack 21 and the measured rotational speed of the generator 13 in real time. The system determines the operating mode and generates corresponding power allocation commands; it then sends speed commands to the speed controller 12 via the CAN bus. and send torque commands to generator controller 32. The generator controller 32 will send torque commands. The control commands are converted into control commands and sent to the conversion module 2. The conversion module 2 receives the control commands from the generator controller 32 and generates corresponding voltages and currents through internal IGBTs and other switching devices. These voltages and currents are applied to the control windings of the generator 13 to generate electromagnetic torque, thereby achieving dual-path coordinated control of the prime mover speed and the generator torque to maintain stable system output frequency and prevent prime mover overload.

[0039] As an example, the central controller 31 may employ a power management system (PMS).

[0040] As an example, the combined diesel and energy storage power supply system coordination control system of this application also includes a first load 5 and a second load 6. The first load 5 is connected between the energy storage module 4 and the generator module 1, and the second load 6 is connected to the generator module 1.

[0041] As an example, the first load 5 is the low-voltage control winding side load, and the second load 6 is the high-voltage power winding side load.

[0042] As an example, the first load 5 can be a 400V load, and the second load 6 can be a 10kV load.

[0043] As an example, the entire diesel-storage combined power supply system operates as follows: The central controller 31 monitors the total load demand and energy storage status on both sides in real time and dynamically decides the operating mode. When the total load power is light and the energy storage is sufficient, the system enters a silent energy storage-only power supply mode. The converter module 2 directly drives the first load 5 and actively controls the dual-stator induction generator as a rotary transformer to output a stable voltage on the high-voltage side to supply power to the second load 6. When the total load power increases or the energy storage is insufficient, the prime mover 11 is started, and the diesel-storage combined power supply mode is entered. At this time, the prime mover 11 increases its speed according to the power demand to maintain a constant high-voltage side frequency. At the same time, the converter module 2 responds quickly to load fluctuations, directly supports the first load 5, and supplements the high-voltage side power deficit through electromagnetic coupling. During the acceleration of the prime mover 11, the generator torque is dynamically limited to prevent the prime mover 11 from overloading. If the total load power is low and the energy storage needs to be supplemented, the system switches to charging mode. The prime mover 11 simultaneously supplies power to both loads and charges the battery. The diesel-storage combined power supply system of this application realizes differentiated management of high and low voltage loads, dynamic complementarity of diesel and storage energy, and coordinated control of electromechanical response, effectively solving the problem of unstable output frequency caused by increased slip when the generator increases its output power.

[0044] In the aforementioned diesel-storage combined power supply system, a central control module is used to coordinate the speed of the prime mover and the torque of the generator through dual-path control. Combined with the collaborative architecture of the dual-stator induction generator and the energy storage module, dynamic power balance and rapid response of diesel and energy storage are achieved. By utilizing the electrical isolation characteristics of the high and low voltage windings of the dual-stator induction generator, the energy storage module can flexibly inject or extract active power through the low voltage winding. Thus, when the load suddenly increases, the energy storage module can compensate for the power deficit in milliseconds, maintain frequency stability and prevent prime mover overload. This effectively solves the coupling problem between the power and frequency of the induction generator and improves the frequency stability and dynamic shock resistance of the system.

[0045] In another embodiment, referring to Figure 2, this application also provides a coordinated control method for a diesel-storage combined power supply system, integrated into a computer device for controlling the aforementioned diesel-storage combined power supply system, which may include the following steps: steps S1 to S4.

[0046] Step S1: Obtain operating status data and determine the total load power.

[0047] Step S2: Determine the working mode based on the total load power and the preset logic threshold, and allocate the total load power to the generator target power and the energy storage target power; the working modes include energy storage separate power supply mode, generator separate power supply mode, diesel and energy storage combined power supply mode, and energy storage charging mode.

[0048] Step S3: When the working mode is energy storage independent power supply mode, the prime mover is stopped and the voltage speed control strategy is used to maintain the output voltage stability.

[0049] Step S4: When the working mode is generator-only power supply mode, diesel-storage combined power supply mode, or energy storage charging mode, execute the coordination control strategy to maintain stable output voltage through the coordination control of the first path and the second path.

[0050] The coordinated control method for the diesel-storage combined power supply system in this application achieves optimal energy allocation under different load conditions by applying different control strategies to four typical operating conditions: independent power supply to energy storage, independent power supply to the generator, combined diesel-storage power supply, and energy storage charging. When energy storage is powered independently, controlling the prime mover to shut down effectively reduces no-load losses, fuel consumption, and noise emissions, improving the system's silent operation capability and environmental benefits. In other modes, through the coordinated control of the first and second paths, it can quickly respond to load fluctuations, ensuring high stability of the output voltage and enhancing the system's adaptability to dynamic loads. This method, through refined mode management and multi-path coordinated control, significantly improves operating efficiency and extends equipment life while ensuring power supply reliability. It effectively solves the coupling problem between induction generator power and frequency, improving the system's frequency stability and dynamic shock resistance.

[0051] In step S1, please refer to step S1 in Figure 2 to obtain operating status data and determine the total load power.

[0052] Specifically, operating status data is acquired in real time through high-frequency sampling via a power management system (PMS).

[0053] As an example, operating status data may include the generator's current speed ω, output bus voltage and output bus current, and the energy storage unit's current state of charge (SOC).

[0054] As an example, the state of charge (SOC) can be estimated in real time using a fusion algorithm based on the ampere-hour integration method and supplemented by periodic open-circuit voltage correction.

[0055] As an example, sensors can be used to acquire corresponding operational status data.

[0056] As an example, the optimal fuel efficiency power range of the prime mover can be set according to the inherent characteristics of the prime mover itself. gen_optmin ,P gen_optmas ] represents the output power range where the prime mover has the highest fuel efficiency, where P gen_optmin P represents the minimum stable output power allowed by the prime mover. gen_optmas This indicates the point at which the prime mover achieves the highest output power efficiency, i.e., the optimal efficiency operating point of the prime mover.

[0057] As an example, the optimal fuel efficiency power range of the prime mover can be set to [50%, 100%].

[0058] Furthermore, based on the real-time measured output bus voltage and output bus current, the current actual output total load power P is determined. load .

[0059] In step S2, please refer to step S2 in Figure 2. The working mode is determined according to the total load power and the preset logic threshold. The total load power is allocated to the generator target power and the energy storage target power. The working modes include energy storage separate power supply mode, generator separate power supply mode, diesel and energy storage combined power supply mode, and energy storage charging mode.

[0060] Specifically, based on the current state of charge (SOC) of the energy storage module and the total load power (P) load The operating mode is determined by a preset logic threshold; the operating modes include energy storage standalone power supply mode, generator standalone power supply mode, diesel-energy storage combined power supply mode, and energy storage charging mode.

[0061] As an example, the preset logic thresholds may include the upper limit of state of charge (SOC). high State of charge (SOC) low State of charge (SOC) target value obj and generator starting power threshold P start , among which, (SOC low SOC high ) indicates the normal range of the state of charge (SOC).

[0062] Specifically, when SOC > SOC high And P load <min(P ess_max ,P start When SOC ≤ SOC, it is in energy storage independent power supply mode; when SOC ≤ SOC low or P load When the prime mover is in its optimal fuel efficiency power range and the state of charge (SOC) is within the normal range, the generator operates in standby mode; when the SOC is within the normal range and P... loadWhen a sudden increase occurs or exceeds the optimal efficiency operating point of the prime mover, the combined diesel and energy storage power supply mode is activated; when the SOC... <SOC obj And P load <P gen_optmas When in energy storage charging mode, SOC represents the state of charge; P load P represents the total load power; ess_max This indicates the maximum safe power output of the energy storage module at any given moment, affected by real-time monitoring of battery temperature, health status, and current SOC; P start Indicates the generator starting power threshold; SOC high Indicates the upper limit of the state of charge; SOC low Indicates the lower limit of the state of charge; SOC obj P represents the target value of the state of charge; gen_optmas This indicates the optimal efficiency operating point of the prime mover.

[0063] As an example, the preset logic threshold can be set based on different battery types and actual needs, such as the upper limit of state of charge (SOC). high It can be set to 85%~95% of the battery's rated capacity; the minimum state of charge (SOC) is [not specified]. low It can be set to 15%~25% of the battery's rated capacity; the minimum state of charge (SOC) target value. obj It can be set to 50%~60% of the battery's rated capacity; generator starting power threshold P start The generator's rated power can be set to 50%.

[0064] Furthermore, the total load power is allocated to the generator target power and the energy storage target power. Specifically, for the energy storage-only power supply mode, when SOC > SOC high And P load <min(P ess_max ,P start When setting the generator target power P, the generator target power can be set. gen = 0, target energy storage power P ess =P load The central controller sends a shutdown command to the prime mover module, disconnecting the mechanical connection between the prime mover and the generator, or causing the prime mover to start but not inject oil. When SOC > SOC high And P load <P ess_max Then set the generator target power P. gen =0, target energy storage power P ess =P load Stop the prime mover.

[0065] Furthermore, for generator-only power supply mode, SOC ≤ SOC low or P loadWhen the prime mover is within its optimal fuel efficiency power range and the state of charge (SOC) is within the normal range, the generator target power P can be set. gen =P load Energy storage target power P ess =0, providing only reactive power support. Start the prime mover.

[0066] Furthermore, for the combined diesel and energy storage power supply mode, when the SOC is within the normal range and P load A sudden increase or exceeding the optimal efficiency operating point P of the prime mover occurs. gen_optmas At that time, the generator target power P can be... gen Set at the optimal efficiency operating point P of the prime mover gen_optmas The remaining power gap is compensated by the energy storage module, i.e., P gen =P gen_optmas Energy storage target power The prime mover and the energy storage converter work together to smooth out load fluctuations by utilizing the fast response characteristics of energy storage.

[0067] Furthermore, regarding the energy storage charging mode, if the SOC <SOC obj And P load <P gen_opt Let the target power of the generator be P gen =P load +P charge The energy storage unit acts as a load, and the target energy storage power is... At this time, the prime mover drives the generator to run, charging the battery while meeting the load requirements. P charge This is the preset charging power.

[0068] As an example, the preset charging power P charge The target power P of the generator can be dynamically calculated by back-calculating from the optimal efficiency operating point of the prime mover. gen Set to P gen_optmas This allows for dynamic adjustment of the preset charging power. .

[0069] In step S3, please refer to step S3 in Figure 2. When the working mode is the energy storage independent power supply mode, the prime mover is stopped and a voltage speed control strategy is adopted to maintain the output voltage stability.

[0070] Specifically, when the operating mode is energy storage-only power supply mode, the central controller sends a shutdown command to the prime mover module, controlling the energy storage module to transfer power to the high-voltage power winding through the low-voltage control winding of the generator module. Since the prime mover stops, the system loses its original mechanical power source and speed support. To maintain a constant output frequency and stable output voltage amplitude on the high-voltage power winding side, a voltage-speed control strategy, i.e., speed-voltage outer loop control, is adopted. Under this strategy, the generator module's control winding no longer follows the rotor but is actively excited by the converter module, actively establishing a rotating magnetic field in the air gap, thus making the generator operate in a rotating transformer state. At this time, part of the energy provided by the energy storage module is used to supply the load, and the other part is used to maintain the no-load rotational losses of the rotor in the generator module.

[0071] As an example, a clutch can be used to mechanically separate the prime mover from the generator rotor, thereby eliminating mechanical friction losses caused by the prime mover bearings and other components spinning idly or being dragged.

[0072] In step S4, please refer to step S4 in Figure 2. When the working mode is generator-only power supply mode, diesel-storage combined power supply mode, or energy storage charging mode, a coordinated control strategy is executed to maintain stable output voltage through coordinated control of the first path and the second path.

[0073] As an example, please refer to Figure 2. Step S4 may include the following steps: Step S41 to Step S44.

[0074] Step S41: When the working mode is generator-only power supply mode, diesel-storage combined power supply mode, or energy storage charging mode, execute the coordination control strategy and perform coordination control through the first path and the second path.

[0075] Step S42: The first path includes determining the reference torque based on the generator target power, calculating the target slip angular frequency required to generate the reference torque based on the induction generator torque-slip characteristics, and superimposing the grid target synchronization angular frequency with the target slip angular frequency to obtain the prime mover speed command.

[0076] Step S43: The second path includes setting an initial torque command based on the generator target power or voltage loop output, calculating the deviation between the measured speed of the prime mover and the prime mover speed command, correcting the initial torque command through a torque limiting circuit, and obtaining the final torque command.

[0077] Step S44: Control the prime mover governor and generator controller according to the prime mover speed command and final torque command respectively to achieve stable output voltage.

[0078] Specifically, in step S41, when the working mode is generator-only power supply mode, diesel-storage combined power supply mode, or energy storage charging mode, a coordinated control strategy is executed, and parallel control is achieved through the first path and the second path.

[0079] In step S42, the first path includes determining the reference torque based on the generator target power, calculating the target slip angular frequency required to generate the reference torque based on the induction generator torque-slip characteristics, and superimposing the grid target synchronization angular frequency with the target slip angular frequency to obtain the prime mover speed command.

[0080] As an example, please refer to Figure 3. Step S42 may include the following steps: Step S421 to Step S423.

[0081] Step S421: Determine the reference torque based on the generator target power.

[0082] Step S422: Determine the slip angular frequency based on the motor equations.

[0083] Step S423: Add the target synchronization angular frequency of the power grid to the slip angular frequency to obtain the speed command of the prime mover.

[0084] Specifically, in step S421, for the first path, based on the generator target power P... gen Determine the reference torque T base The expression is: in, This indicates the measured speed of the prime mover. Since the prime mover and generator are mechanically coaxially rigidly connected, their speeds are completely synchronized in steady state and most dynamic processes, with no slippage. Therefore, the measured speed of the prime mover... With the current speed of the generator same.

[0085] Further, in step S422, the electromagnetic torque of the induced motor is determined according to the motor equation. With slip angular frequency Approximately proportional, the expression is: in, Indicates the stator phase voltage. Indicates synchronous angular velocity, This represents the rotor resistance referred to the stator side. Indicates the torque coefficient. This represents the Laplace operator.

[0086] As an example, the stator phase voltage U can be sampled and measured in real time by a voltage sensor, or the voltage command value of the converter can be read directly.

[0087] As an example, synchronous angular velocity It can be calculated based on the power supply frequency f and the number of motor pole pairs p, and the expression is: .

[0088] As an example, the rotor resistance referred to the stator side You can consult the parameter data sheet provided by the motor manufacturer.

[0089] As an example, torque coefficient The linear relationship between torque and slip can be tested through a motor bench test within a low slip range to obtain a fitted straight line. The slope of this fitted straight line is the torque coefficient. .

[0090] Furthermore, the deviation between the measured speed of the prime mover and the speed command of the prime mover can be deduced. , i.e., slip angular frequency, is expressed as: in, As the reference torque, This is the torque coefficient.

[0091] Furthermore, in step S423, in order to keep the grid frequency constant at the target synchronization angular frequency... The physical speed of the prime mover must be higher than the synchronous speed, and the excess must be the slip. Therefore, the target synchronous angular frequency of the power grid can be... With slip angular frequency Add them together to obtain the speed command of the prime mover. The expression is: in, , representing the slip coefficient; The reference torque; This is the torque coefficient.

[0092] As an example, the target synchronization angular frequency of the power grid This is the angular velocity corresponding to the rated frequency.

[0093] As an example, the core logic of the first path is to actively increase the speed of the prime mover so that the increase is equal to the slip increment required due to the increase in load, thereby ensuring that the magnetic field synchronous speed remains unchanged.

[0094] As an example, during a sudden load surge, while the first path provides a speed command, the prime mover, being a mechanical component, requires several seconds to increase its speed. In contrast, the converter, being an electronic component, can establish a large electromagnetic torque within milliseconds. Without constraints, the converter will immediately establish the corresponding generator target power P. genThe large torque will act on the prime mover shaft before it has accelerated, causing the prime mover speed to drop instantly, or even shut down, and the frequency to collapse. Therefore, a second path can be executed for coordinated control.

[0095] In step S43, the second path includes setting an initial torque command based on the generator target power or voltage loop output, calculating the deviation between the measured speed of the prime mover and the prime mover speed command, correcting the initial torque command through a torque limiting circuit, and obtaining the final torque command.

[0096] As an example, please refer to Figure 3. Step S43 may include the following steps: Step S431 to Step S433.

[0097] Step S431: Generate the initial torque command using either a voltage loop or a power loop depending on the operating mode.

[0098] Step S432: Calculate the deviation between the measured speed of the prime mover and the speed command of the prime mover.

[0099] Step S433: Based on the deviation, the initial torque command is corrected through the torque limiting circuit to obtain the final torque command.

[0100] Specifically, in step S431, the initial torque command is generated using either a voltage loop or a power loop depending on the operating mode. The central controller automatically switches between two modes based on real-time operating conditions: power loop mode is used during normal power distribution; when a sudden load change causes a large voltage fluctuation, it switches to voltage loop mode.

[0101] As an example, in the power loop case, the power is directly based on the generator target power P. gen Determine the initial torque command The expression is: in, The measured speed of the prime mover is given, and the power loop is suitable for operating conditions where precise control of active power is the priority.

[0102] As an example, in the voltage loop scenario, the initial torque command is generated based on the PI controller. The expression is: in, , These are the proportional gain and integral gain coefficients of the voltage loop, respectively. The target value for generator terminal voltage. This is the measured value of the generator terminal voltage. For time.

[0103] As an example, the voltage loop can be set to automatically activate when a voltage deviation exceeding a preset threshold (e.g., ±5%) is detected, prioritizing the protection of system voltage stability.

[0104] As an example, the preset threshold can be set according to the actual situation, and no restrictions are imposed here.

[0105] Further, in step S432, the measured speed of the prime mover is calculated. With prime mover speed command The deviation.

[0106] Furthermore, in step S433, based on the deviation, the initial torque command is adjusted through a torque limiting circuit. Make corrections to obtain the final torque command. .

[0107] As an example, the torque limiting circuit may include a dynamic saturator, which is related to the measured speed of the prime mover. The function that detects the measured speed of the prime mover. It is in the process of acceleration but has not yet reached the prime mover speed command. At that time, limit the final torque command The torque limit is not exceeded, which is the maximum residual torque that the prime mover can provide at the current speed. .

[0108] As an example, the measured speed of the prime mover It is in the process of acceleration but has not yet reached the prime mover speed command. It can be set to the measured speed of the prime mover. Less than the prime mover speed command And its measured speed change rate Not less than zero.

[0109] As an example, the working process of the torque limiting circuit is as follows: compare the measured speed of the prime mover. With prime mover speed command ,when Furthermore, if the deviation exceeds a preset threshold, the final torque command will be forcibly reduced or limited. The rising slope.

[0110] As an example, the final torque command Must meet: ,in, For maximum torque, This is a portion of the maximum torque reserved for acceleration.

[0111] Specifically, if the measured speed of the prime mover The prime mover speed command was not reached. This indicates that acceleration is in progress, and the actual measured speed of the prime mover can be used as a reference. Determine the maximum torque that the prime mover can provide. To ensure the prime mover has sufficient acceleration capability, from maximum torque... Reserve a portion of acceleration torque This forms a dynamic torque limiting value. For the initial torque command Apply dynamic torque limit value When the initial torque command At that time, the final torque command is forced. The final torque command is controlled via a slope limiter (not shown). The rate of increase is controlled to prevent abrupt changes. As the prime mover speed gradually increases under the action of the governor, the measured speed of the prime mover... Approximating prime mover speed command Dynamic torque limit value Gradually release the pressure until the measured speed of the prime mover is reached. Reach the prime mover speed command Dynamic torque limit value Remove restrictions, final torque command Smooth transition to the generator target power P gen .

[0112] As an example, the maximum torque can be determined by looking up a table or by online calculation. The maximum torque The relationship with rotational speed can be stored in the prime mover external characteristic curve function in the controller, which is taken from the test data provided by the prime mover manufacturer.

[0113] As an example, dynamic torque limit value It is a real-time dynamically calculated value, expressed as: in, This indicates the maximum torque at the current measured speed of the prime mover. This indicates the reserved acceleration torque. (The text then abruptly shifts to a seemingly unrelated topic: "as the measured speed of the prime mover...") Dynamic torque limit value as speed increases from idle to rated speed The value will gradually and smoothly increase from 0 to the final torque command. .

[0114] As an example, acceleration torque The value can be determined based on the rotational inertia of the generator module and the desired speed response time, and can be set to 5% to 15% of the generator's rated torque.

[0115] Further, in step S44, the speed governor receives the prime mover speed command. And drive the prime mover to track the prime mover speed command. This causes the mechanical speed of the prime mover to increase synchronously. Due to the prime mover speed command... The slip corresponding to the load has been compensated, and the frequency of the electromotive force induced on the stator side of the dual-stator induction generator is locked at the target synchronization angular frequency. This achieves a constant output frequency.

[0116] Furthermore, the generator controller receives the final torque command. It then converts these into control instructions that the transformation module can execute.

[0117] Specifically, the generator controller receives the final torque command. The final torque command As a given value of electromagnetic torque Compared with the actual value of electromagnetic torque The deviation value is compared and passed through a PI controller to obtain the q-axis component of the control winding current setpoint. Calculate the q-axis component of the control winding current setpoint. q-axis component of the actual value of the control winding current The difference is then used to obtain the q-axis component of the voltage setpoint through a PI controller. ; Calculate the setpoint of the control winding voltage Compared with the actual value of the control winding voltage The deviation is then used to obtain the d-axis component of the control winding current setpoint via a PI regulator. Calculate the d-axis component of the control winding current setpoint. d-axis component of the actual value of the control winding current The difference is then used to obtain the d-axis component of the voltage setpoint through a PI controller. d-axis component of voltage setpoint q-axis component of voltage setpoint The coordinate transformation is performed, and then a switching signal is generated by space vector pulse width modulation (SVPWM) to drive the conversion module 2. The switching devices inside the conversion module 2 generate corresponding voltage and current, which are applied to the control winding of the generator 13 to generate electromagnetic torque, ultimately achieving precise adjustment and stable maintenance of the generator output voltage amplitude.

[0118] As an example, the control winding current setpoint can be obtained through a current sensor, and the control winding voltage setpoint can be obtained through a voltage sensor. The actual value of the electromagnetic torque can then be calculated based on the control winding current setpoint and the control winding voltage setpoint.

[0119] As an example, after completing the current execution cycle of the coordinated control, the system returns to step S1 to start the next control cycle. Through the above-mentioned parallel dual-path coordinated control, the first path provides feedforward compensation control for the prime mover speed, maintaining a constant output frequency; the second path provides feedback limiting control for the generator torque, effectively preventing the prime mover from overload shutdown during load changes. Combined with the voltage closed loop inside the generator controller, the overall dynamic stability and shock resistance of the system are improved, achieving high stability of the output voltage frequency and amplitude of the diesel-storage combined power supply system under load changes.

[0120] In one example, Figure 4 shows the waveform of the output frequency during a load surge. To verify the dynamic performance of this application, a load surge test was conducted. During the test, the frequency of the system's rated output voltage target value was set to 50Hz, and the voltage amplitude was 10kV. The system initially operated stably under load in this state. At t=0.6s, the total load power P... load A sudden, abrupt increase occurs. As shown in Figure 4, after the load increases, due to the mechanical inertia of the prime mover, its speed cannot increase instantaneously, leading to an increase in the generator's electromagnetic slip. This, in turn, causes a brief drop in the generator's output frequency. Subsequently, the energy storage module rapidly injects active power through the generator's control windings to provide support. Simultaneously, the speed command in the first path causes the prime mover to accelerate, while the torque limiting circuit in the second path prevents overload. Under the coordinated control of both, the output frequency quickly recovers and stabilizes at 50Hz. The entire process demonstrates the ability of the control method in this application to maintain a stable output frequency under sudden load changes.

[0121] In the coordinated control method of the diesel-storage combined power supply system proposed in this application, the prime mover is ensured to operate in the high-efficiency range through intelligent switching and power distribution of four operating modes; an adaptive selection control strategy ensures that the prime mover always operates at the optimal efficiency point, thereby achieving optimal overall system energy efficiency; the prime mover speed is actively increased through the first path to compensate for the increased slip rate caused by the increase in load, thereby maintaining a constant output frequency; the parallel action of the first and second paths effectively solves the dynamic conflict between the rapid torque response of the power electronic converter and the mechanical inertia of the prime mover when the load suddenly increases; and the dynamic limiting link can limit the electromagnetic torque of the generator when the prime mover speed lags, preventing the prime mover from shutting down due to overload. This method can effectively solve the coupling problem between the power and frequency of the induction generator, improving the frequency stability and dynamic shock resistance of the system.

[0122] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0123] In another embodiment, this application also provides a computer device, including one or more processors; a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the coordinated control method of the diesel-storage combined power supply system described in the above specific embodiments.

[0124] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0125] Although this application has been disclosed above with reference to embodiments, it is not intended to limit this application. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of this application.

Claims

1. A coordinated control method for a combined diesel and energy storage power supply system, characterized in that, The diesel-storage combined power supply system includes a generator module, a converter module, and an energy storage module. The energy storage module is connected to the DC input terminal of the converter module to supply power to the converter module. The AC output terminal of the converter module is connected to the generator module to input excitation power to the generator module. The generator module includes a prime mover and a generator. The prime mover drives the rotor of the generator to rotate. The coordinated control method of the diesel-storage combined power supply system includes the following steps: acquiring operating status data and determining the total load power; determining the operating mode based on the total load power and a preset logic threshold, and allocating the total load power to the generator target power and the energy storage target power; the operating modes include energy storage separate power supply mode, generator separate power supply mode, diesel-storage combined power supply mode, and energy storage charging mode; when the operating mode is the energy storage separate power supply mode, the prime mover is shut down, and a voltage-speed control strategy is adopted to maintain stable output voltage; when the operating mode is the generator separate power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed, and output voltage is maintained stable through first path and second path coordinated control.

2. The coordinated control method for a combined diesel and energy storage power supply system according to claim 1, characterized in that, The operating mode is determined based on the total load power and a preset logic threshold, including: when SOC > SOC high And P load < min(P ess_max ,P start When SOC ≤ SOC, it is in energy storage independent power supply mode; when SOC ≤ SOC low or P load When the prime mover is in its optimal fuel efficiency power range and the state of charge (SOC) is within the normal range, the generator operates in standby mode; when the SOC is within the normal range and P... load When a sudden increase occurs or exceeds the optimal efficiency operating point of the prime mover, the combined diesel and energy storage power supply mode is activated; when the SOC (State of Charge)... <SOC obj And P load <P gen_optmas When in this mode, it is in energy storage charging mode; where SOC represents the state of charge, P load P represents the total load power. ess_max P represents the maximum power that the energy storage module can safely output at any given moment. start State of Charge (SOC) indicates the generator starting power threshold. high Indicates the upper limit of the state of charge (SOC). low Indicates the lower limit of the state of charge (SOC). obj P represents the target value of the state of charge. gen_optmas This indicates the optimal efficiency operating point of the prime mover.

3. The coordinated control method for a combined diesel and energy storage power supply system according to claim 2, characterized in that, The total load power is allocated to the generator target power and the energy storage target power, including: for the energy storage-only power supply mode, when SOC > SOC high And P load < min(P ess_max ,P start When setting the generator target power P, gen = 0, target energy storage power P ess =P load When SOC > SOC high And P load <P ess_max Then set the generator target power P. gen =0, target energy storage power P ess =P load For generator-only power supply mode, set the generator target power P. gen =P load Energy storage target power P ess =0; For the combined diesel and energy storage power supply mode, when the SOC is within the normal range and P load A sudden increase or exceeding the optimal efficiency operating point P of the prime mover occurs. gen_optmas At that time, the generator target power P gen Set at the optimal efficiency operating point P of the prime mover gen_optmas That is, P gen =P gen_optmas Energy storage target power For energy storage charging mode, if SOC <SOC obj And P load <P gen_opt Then set the generator target power P gen =P load +P charge Energy storage target power Among them, P charge The preset charging power is given by SOC, which represents the state of charge. load P represents the total load power. ess_max P represents the maximum power that the energy storage module can safely output at any given moment. start State of Charge (SOC) indicates the generator starting power threshold. high Indicates the upper limit of the state of charge (SOC). low Indicates the lower limit of the state of charge (SOC). obj P represents the target value of the state of charge. gen_optmas This indicates the optimal efficiency operating point of the prime mover.

4. The coordinated control method for the combined diesel and energy storage power supply system according to claim 1, characterized in that, When the operating mode is the generator-only power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed to maintain stable output voltage through coordinated control via a first path and a second path. This includes: when the operating mode is the generator-only power supply mode, the diesel-storage combined power supply mode, or the energy storage charging mode, a coordinated control strategy is executed through a first path and a second path; the first path includes: determining the reference torque based on the generator's target power; calculating the target slip angular frequency required to generate the reference torque based on the induction generator's torque-slip characteristics; superimposing the grid target synchronization angular frequency with the target slip angular frequency to obtain the prime mover speed command; the second path includes: setting the initial torque command based on the generator's target power or voltage loop output; calculating the deviation between the measured prime mover speed and the diesel prime mover speed command; correcting the initial torque command through a torque limiting circuit to obtain the final torque command; and controlling the prime mover speed governor and the generator controller according to the prime mover speed command and the final torque command respectively to achieve stable output voltage.

5. The coordinated control method for the diesel-storage combined power supply system according to claim 4, characterized in that, Prime mover speed command The expression is: in, , representing the slip coefficient; The reference torque; This is the torque coefficient.

6. The coordinated control method for a combined diesel and energy storage power supply system according to claim 5, characterized in that, The torque limiting circuit includes a dynamic saturator, which is related to the measured speed of the prime mover. The function, when the measured speed of the prime mover is detected. Less than the prime mover speed command And the measured rate of change of rotational speed Set the final torque command when it is not less than zero. Less than or equal to the maximum residual torque that the prime mover can provide.

7. The coordinated control method for a combined diesel and energy storage power supply system according to claim 6, characterized in that, The maximum residual torque that the prime mover can provide is the dynamic torque limit value. The expression is: in, This indicates the maximum torque at the current measured speed of the prime mover. Acceleration torque reserved within the maximum torque.

8. The coordinated control method for a combined diesel and energy storage power supply system according to claim 7, characterized in that, The method is integrated into a computer device, the computer device including one or more processors; a storage device for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the coordinated control method of the diesel-storage combined power supply system.

9. A combined diesel and energy storage power supply system, characterized in that, The coordinated control method for a combined diesel and energy storage power supply system as described in any one of claims 1 to 8 includes: a generator module, a converter module, a central control module, and an energy storage module. The central control module acquires the measured rotational speed of the generator module and the charge state of the energy storage module, and sends a rotational speed command and a control command to the generator module. The generator module receives the rotational speed command output by the central control module and generates electricity. The energy storage module is connected to the DC input terminal of the converter module to provide DC power to the converter module. The AC output terminal of the converter module is connected to the generator module to input excitation energy to the generator module.

10. The combined diesel and energy storage power supply system according to claim 9, characterized in that, The generator module includes a prime mover, a speed governor, and a generator. The speed governor receives speed commands from the central control module and controls the mechanical torque output by the prime mover by adjusting the fuel supply or throttle opening. The prime mover drives the rotor of the generator to rotate.

Images