A flywheel energy storage device-based demagnetization power supply control method, system and device

Abstract

The application relates to a demagnetization power supply control method, system and equipment based on a flywheel energy storage device, and belongs to the technical field of pulse power supply design. The system comprises a power grid side rectifier, a four-quadrant DC / DC converter, a flywheel side converter, a bidirectional DC / DC converter and a centralized control console; the power grid side rectifier is controlled in a constant power mode; the four-quadrant DC / DC converter is used for controlling the waveform of the current of a demagnetization coil and limiting the power size of the demagnetization coil; the flywheel side converter charges and discharges a flywheel motor according to the power of the demagnetization coil; the bidirectional DC / DC converter is used for maintaining the constancy of a DC bus voltage; and the centralized control console is responsible for monitoring the states of different converters and issuing control instructions. The application can coordinate the power and voltage outputs of the converters, meet the pulse current output demand of the demagnetization coil, ensure the safe and stable operation of the power supply system, and is easy to popularize and apply.

Description

Technical Field

[0001] This invention belongs to the field of pulse power supply design technology, specifically relating to a demagnetizing power supply control method, system and equipment based on a flywheel energy storage device. Background Technology

[0002] Due to the effects of the Earth's magnetic field and stress, ships will gradually become magnetized during navigation, generating a fixed magnetic field. This magnetic field will remain for a long time and is not easy to dissipate, making it a target for air and underwater magnetic field detection and a significant source of threat from magnetic weapons. Implementing fixed magnetic treatment is an important measure to improve the magnetic protection capability of ships and ensure their safety.

[0003] The principle of ship magnetic treatment is to generate an alternating magnetic field on the demagnetizing coil by outputting a series of alternating pulse currents with gradually decreasing amplitude from the demagnetizing main power supply. This disrupts the distribution of magnetic domains in the ship's ferromagnetic materials, causing them to no longer exhibit fixed magnetism on a macroscopic scale. For large ships, the high power and energy of the pulse currents make it impossible for mains power or diesel generators to meet the power requirements. Furthermore, energy storage devices such as batteries and supercapacitors suffer from low power and energy density, making them unsuitable for demagnetizing large ships. Considering the rapid development of flywheel energy storage technology in recent years and its widespread application in areas such as grid frequency regulation and subways, flywheel energy storage offers high power density and rapid response to sudden load changes, making it particularly suitable for demagnetizing applications. Therefore, developing flywheel energy storage demagnetizing main power supplies is a major trend.

[0004] However, flywheel demagnetizing main power supplies involve multiple converters, and reducing grid power fluctuations while meeting load power demands presents significant control complexity. Existing demagnetizing main power supplies do not utilize flywheel energy storage devices, and flywheel energy storage is primarily used in grid frequency regulation, subway energy management, and UPS systems, which differ considerably from demagnetizing conditions. Therefore, there are no readily available control algorithms for reference. Thus, overcoming the shortcomings of existing technologies and designing a demagnetizing power supply control method, system, and equipment based on flywheel energy storage devices is of significant engineering importance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a demagnetizing power supply control method, system, and device based on a flywheel energy storage device. This invention can coordinate the power and voltage output of each converter in the demagnetizing power supply, meet the power supply requirements of the demagnetizing coil, and ensure the efficient, safe, and stable operation of the power system.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A demagnetizing power supply control method based on a flywheel energy storage device is provided, which employs a demagnetizing power supply control system based on a flywheel energy storage device. The demagnetizing power supply control system based on a flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console.

[0008] The AC side of the grid-side rectifier is connected to the power grid via a transformer, while the DC side is a DC bus.

[0009] One end of the four-quadrant DC / DC converter and one end of the bidirectional DC / DC converter are both connected to the DC bus.

[0010] The other end of the four-quadrant DC / DC converter is connected to the demagnetizing coil;

[0011] The flywheel motor is connected to the other end of the bidirectional DC / DC converter via a flywheel-side converter.

[0012] The centralized control console is connected to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, respectively. It is used to monitor the status of the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, and to issue power commands to the grid-side rectifier, pulse current commands to the four-quadrant DC / DC converter, current inner loop commands to the flywheel-side converter, and current inner loop commands to the bidirectional DC / DC converter.

[0013] The grid-side rectifier is used to perform constant power mode control based on the power commands issued by the central control console.

[0014] A four-quadrant DC / DC converter is used to control the current waveform of the demagnetizing coil and limit the power of the demagnetizing coil.

[0015] The flywheel-side converter is used to charge and discharge the flywheel motor according to the power of the demagnetizing coil;

[0016] A bidirectional DC / DC converter is used to maintain a constant DC bus voltage.

[0017] Furthermore, preferably, the specific method for constant power mode control of the grid-side rectifier is as follows:

[0018] Based on the power command issued by the central control console to the grid-side rectifier, calculate the command value i of the d-axis current loop. dref Command value i for the q-axis current loop qref Set to 0;

[0019] After rotating coordinate transformation, the grid current yields the feedback values ​​i of the d-axis and q-axis currents. d and i q ;

[0020] Command value i for d-axis current loop dref and the feedback value i of the d-axis current d The error, after passing through the first PI controller, is superimposed with the d-axis component u of the grid voltage. gd and the d-axis decoupling component i of the output filter q ω0L, to obtain the d-axis modulation voltage u d Where ω0 is the fundamental angular frequency of the grid voltage, and L is the value of the filter inductance;

[0021] Command value i for q-axis current loop qref and the feedback value i of the q-axis current q The error, after passing through the second PI controller, is superimposed with the q-axis component u of the grid voltage. gq and the q-axis decoupling component i of the output filter d ω0L, to obtain the q-axis modulation voltage u q ;

[0022] Modulation voltage u d and u q The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

[0023] Furthermore, preferably, the phases of the rotating coordinate transformation and the inverse rotating coordinate transformation are obtained by phase-locking the grid voltage.

[0024] Furthermore, preferably, in a four-quadrant DC / DC converter, the specific method for controlling the waveform of the current in the demagnetizing coil is as follows:

[0025] Pulse current command i dcref The output current i of the four-quadrant DC / DC converter sampled by a current sensor dc The error is processed by the third PI controller to obtain the output of the current closed-loop control;

[0026] Multiply the power of the demagnetizing coil by the reciprocal of its maximum power, K, to obtain the per-unit value x of the demagnetizing coil's power.

[0027] The output of the current closed-loop control is multiplied by 1-x 2 The duty cycle d of the four-quadrant DC / DC converter is obtained; then the switching devices of the four-quadrant DC / DC converter are controlled to realize the current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

[0028] Furthermore, preferably, the flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil, specifically through the following method:

[0029] In the rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted. The voltage outer loop control is implemented in the centralized control console, and the current inner loop control is implemented on the flywheel-side converter.

[0030] The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the preset DC voltage command value U of the flywheel-side converter in the central control console is used. dcrefk DC voltage U of the flywheel-side converter d ck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value i of the q-axis current inner loop. qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value i of the d-axis current inner loop. drefk Set to 0;

[0031] The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​i of the d-axis and q-axis currents. dk and i qk ;

[0032] Command value i of the d-axis current inner loop drefk and the feedback value i of the d-axis current dk The error, after passing through the fifth PI controller, yields the d-axis modulated voltage u. dk ;

[0033] Command value i for the inner loop of the q-axis current qrefk and the feedback value i of the q-axis current qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage u. qk ;

[0034] Modulation voltage u dk and u qk The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

[0035] Furthermore, preferably, the phases of the rotational coordinate transformation and the inverse rotational coordinate transformation are obtained through the position sensor of the flywheel motor.

[0036] Furthermore, preferably, the specific method for the bidirectional DC / DC converter to maintain a constant DC bus voltage is as follows:

[0037] The system employs a DC voltage outer loop control mode and a current inner loop control mode. The DC voltage outer loop control is implemented in a centralized control console, while the DC current inner loop control is implemented on a bidirectional DC / DC converter.

[0038] The voltage outer loop control mode is as follows: the demagnetizing power supply DC bus voltage is the control target, and the preset demagnetizing power supply DC bus voltage command value U in the central control console is used. dcref With the DC voltage U of the bidirectional DC / DC converter d c The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value i of the inner current loop. dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage.

[0039] The current inner loop control mode is as follows: the command value i of the current inner loop is... dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle d of the bidirectional DC / DC converter through the eighth PI controller. k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage.

[0040] The present invention also provides the above-mentioned demagnetizing power control system based on the flywheel energy storage device.

[0041] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the demagnetizing power control method based on the flywheel energy storage device described above.

[0042] The present invention further provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the demagnetizing power control method based on the flywheel energy storage device described above.

[0043] In this invention, a flywheel motor, a flywheel-side rectifier, and a bidirectional DC / DC converter together constitute a flywheel energy storage unit. There can be one or more flywheel energy storage units, which are arranged in parallel. That is, there can be multiple flywheel motors, flywheel-side rectifiers, and bidirectional DC / DC converters. When there are multiple flywheel motors, flywheel-side rectifiers, and bidirectional DC / DC converters, the number of flywheel motors, flywheel-side rectifiers, and bidirectional DC / DC converters is the same.

[0044] In this invention, the flywheel-side converter adopts a voltage outer loop-current inner loop control scheme, that is, it adopts a voltage outer loop control mode and a current inner loop control mode. The outer loop controls the DC voltage of the flywheel-side converter as the control target, and the inner loop controls the output AC current of the flywheel-side converter.

[0045] In this invention, when sampling the output current of the four-quadrant DC / DC converter and the output AC current of the flywheel-side converter, sampling can be performed using a conventional current sensor. This invention does not limit the specific sampling method.

[0046] Compared with the prior art, the beneficial effects of this invention are as follows:

[0047] The present invention provides a demagnetizing power supply control method, system and equipment based on a flywheel energy storage device, which can coordinate the power and voltage output of each converter of the demagnetizing power supply, meet the power supply requirements of the demagnetizing working coil, and ensure the efficient, safe and stable operation of the power supply system.

[0048] Compared to battery energy storage, flywheel energy storage is a mechanical energy storage method with a lifespan of up to 30 years, while batteries are chemical energy storage devices with a lifespan of less than 10 years. Therefore, flywheel energy storage demagnetizing power supplies have a longer lifespan and lower total lifespan costs. In terms of safety, battery combustion does not rely on oxygen; once a fire occurs, the explosion is almost uncontrollable, requiring the battery to be allowed to burn completely. The combustion and toxic fumes pose significant hazards. Several recent explosions demonstrate the inherent safety risks of battery energy storage. In contrast, flywheel energy storage offers better safety and fewer accidents. Due to their low energy density, supercapacitors can only be used in conjunction with batteries for hybrid energy storage to meet the power and energy requirements of high-power demagnetizing coils.

[0049] Since existing demagnetizing power supplies do not employ flywheel energy storage devices, the demagnetizing power supply control method proposed in this patent is original and cannot be directly compared with existing technologies. However, regarding the control algorithm itself, it has the following technical characteristics:

[0050] (1) The grid-side rectifier is controlled in constant power mode, which greatly improves the stability of the grid. This is especially important for weak grids such as diesel generator sets. In addition, in this mode, the grid can continuously output the maximum allowable power, which can minimize the energy stored in the flywheel and thus reduce the engineering cost of the system.

[0051] (2) The flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil. The bidirectional DC / DC converter is used to maintain the constant DC bus voltage, which can effectively suppress the power surge of the working coil during demagnetizing operation, create conditions for the constant power control of the grid-side rectifier, and store the huge energy fed back when the current of the large inductor demagnetizing coil decreases, so that the large current is rapidly reduced to zero to meet the system indicators.

[0052] (3) The four-quadrant DC / DC converter is used to control the waveform of the current in the demagnetizing coil and limit the power of the demagnetizing coil, which can effectively reduce the instantaneous power demand of the flywheel energy storage device and further reduce the engineering cost of the system.

[0053] (4) The system has grid-side rectifiers, flywheel-side converters, bidirectional DC / DC converters and four-quadrant DC / DC converters. The multiple converters are closely related in terms of power flow, but their control objectives and modes are different. They achieve decoupling control between each other, which simplifies the system control strategy. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the demagnetizing power supply control system based on a flywheel energy storage device according to the present invention;

[0055] Figure 2 This is a block diagram of the grid-side rectifier control of the present invention;

[0056] Figure 3 This is a block diagram of the four-quadrant DC / DC converter control of the present invention;

[0057] Figure 4 This is a control block diagram of the flywheel-side converter of the present invention;

[0058] Figure 5 This is a block diagram of the bidirectional DC / DC converter control of the present invention;

[0059] Figure 6 This is a schematic diagram of the electronic device structure of the present invention;

[0060] Figure 7 This is a simulated waveform of the demagnetizing coil current in an application example of the present invention;

[0061] Figure 8 This is a simulation waveform of the flywheel energy storage unit's output power in an application example of the present invention;

[0062] Figure 9 This is a simulation waveform of the power grid in an application example of the present invention. Detailed Implementation

[0063] The present invention will now be described in further detail with reference to the embodiments.

[0064] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with the techniques or conditions described in the literature in the field or according to the product instructions. Materials or equipment whose manufacturers are not specified are all conventional products that can be obtained by purchase.

[0065] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” to another element, it can be directly connected to the other element, or there may be an intermediate element. Furthermore, the term “connected” as used herein can include wireless connections. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0066] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. The terms "inner," "upper," "lower," etc., indicate the orientation or state relationship based on the orientation or state relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0067] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "equipped with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0069] Example 1

[0070] A demagnetizing power supply control method based on a flywheel energy storage device is proposed, employing a demagnetizing power supply control system based on a flywheel energy storage device; such as Figure 1 As shown, the demagnetizing power control system based on the flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console.

[0071] The AC side of the grid-side rectifier is connected to the power grid via a transformer, while the DC side is a DC bus.

[0072] One end of the four-quadrant DC / DC converter and one end of the bidirectional DC / DC converter are both connected to the DC bus.

[0073] The other end of the four-quadrant DC / DC converter is connected to the demagnetizing coil;

[0074] The flywheel motor is connected to the other end of the bidirectional DC / DC converter via a flywheel-side converter.

[0075] The centralized control console is connected to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, respectively. It is used to monitor the status of the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, and to issue power commands to the grid-side rectifier, pulse current commands to the four-quadrant DC / DC converter, current inner loop commands to the flywheel-side converter, and current inner loop commands to the bidirectional DC / DC converter.

[0076] The grid-side rectifier is used to perform constant power mode control based on the power commands issued by the central control console.

[0077] A four-quadrant DC / DC converter is used to control the current waveform of the demagnetizing coil and limit the power of the demagnetizing coil.

[0078] The flywheel-side converter is used to charge and discharge the flywheel motor according to the power of the demagnetizing coil;

[0079] A bidirectional DC / DC converter is used to maintain a constant DC bus voltage.

[0080] Example 2

[0081] A demagnetizing power supply control method based on a flywheel energy storage device is proposed, employing a demagnetizing power supply control system based on a flywheel energy storage device; such as Figures 1-5 As shown, the demagnetizing power control system based on the flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console.

[0082] The AC side of the grid-side rectifier is connected to the power grid via a transformer, while the DC side is a DC bus.

[0083] One end of the four-quadrant DC / DC converter and one end of the bidirectional DC / DC converter are both connected to the DC bus.

[0084] The other end of the four-quadrant DC / DC converter is connected to the demagnetizing coil;

[0085] The flywheel motor is connected to the other end of the bidirectional DC / DC converter via a flywheel-side converter.

[0086] The centralized control console is connected to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, respectively. It is used to monitor the status of the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, and to issue power commands to the grid-side rectifier, pulse current commands to the four-quadrant DC / DC converter, current inner loop commands to the flywheel-side converter, and current inner loop commands to the bidirectional DC / DC converter.

[0087] The grid-side rectifier is used to perform constant power mode control based on the power commands issued by the central control console.

[0088] A four-quadrant DC / DC converter is used to control the current waveform of the demagnetizing coil and limit the power of the demagnetizing coil.

[0089] The flywheel-side converter is used to charge and discharge the flywheel motor according to the power of the demagnetizing coil;

[0090] A bidirectional DC / DC converter is used to maintain a constant DC bus voltage.

[0091] The specific method for constant power mode control of the grid-side rectifier is as follows:

[0092] Based on the power command issued by the central control console to the grid-side rectifier, calculate the command value i of the d-axis current loop. dref Command value i for the q-axis current loop qref Set to 0;

[0093] After rotating coordinate transformation, the grid current yields the feedback values ​​i of the d-axis and q-axis currents. d and i q ;

[0094] Command value i for d-axis current loop dref and the feedback value i of the d-axis current d The error, after passing through the first PI controller, is superimposed with the d-axis component u of the grid voltage. gd and the d-axis decoupling component i of the output filter q ω0L, to obtain the d-axis modulation voltage u d Where ω0 is the fundamental angular frequency of the grid voltage, and L is the value of the filter inductance;

[0095] Command value i for q-axis current loop qref and the feedback value i of the q-axis current q The error, after passing through the second PI controller, is superimposed with the q-axis component u of the grid voltage. gq and the q-axis decoupling component i of the output filterd ω0L, to obtain the q-axis modulation voltage u q ;

[0096] Modulation voltage u d and u q The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

[0097] The phases of the rotating coordinate transformation and the inverse rotating coordinate transformation are obtained by phase-locking the grid voltage.

[0098] In a four-quadrant DC / DC converter, the specific method for controlling the waveform of the current in the demagnetizing coil is as follows:

[0099] Pulse current command i dcref The output current i of the four-quadrant DC / DC converter sampled by a current sensor dc The error is processed by the third PI controller to obtain the output of the current closed-loop control;

[0100] Multiply the power of the demagnetizing coil by the reciprocal of its maximum power, K, to obtain the per-unit value x of the demagnetizing coil's power.

[0101] The output of the current closed-loop control is multiplied by 1-x 2 The duty cycle d of the four-quadrant DC / DC converter is obtained; then the switching devices of the four-quadrant DC / DC converter are controlled to realize the current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

[0102] The flywheel-side converter charges and discharges the flywheel motor based on the power of the demagnetizing coil. The specific method is as follows:

[0103] In a rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted;

[0104] The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the preset DC voltage command value U of the flywheel-side converter in the central control console is used. dcrefk DC voltage U of the flywheel-side converter dck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value i of the q-axis current inner loop. qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value i of the d-axis current inner loop. drefk Set to 0;

[0105] The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​i of the d-axis and q-axis currents. dk and i qk ;

[0106] Command value i of the d-axis current inner loop drefk and the feedback value i of the d-axis current dk The error, after passing through the fifth PI controller, yields the d-axis modulated voltage u. dk ;

[0107] Command value i for the inner loop of the q-axis current qrefk and the feedback value i of the q-axis current qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage u. qk ;

[0108] Modulation voltage u dk and u qk The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

[0109] The phases of the rotational and inverse rotational coordinate transformations are obtained through the position sensor of the flywheel motor.

[0110] The specific method for maintaining a constant DC bus voltage in a bidirectional DC / DC converter is as follows:

[0111] It adopts a DC voltage outer loop control mode and a current inner loop control mode;

[0112] The voltage outer loop control mode is as follows: the demagnetizing power supply DC bus voltage is the control target, and the preset demagnetizing power supply DC bus voltage command value U in the central control console is used. dcref With the DC voltage U of the bidirectional DC / DC converter dc The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value i of the inner current loop. dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage.

[0113] The current inner loop control mode is as follows: the command value i of the current inner loop is... dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle d of the bidirectional DC / DC converter through the eighth PI controller. k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage.

[0114] Example 3

[0115] A demagnetizing power supply control method based on a flywheel energy storage device is proposed, employing a demagnetizing power supply control system based on a flywheel energy storage device; such as Figure 1 As shown, the demagnetizing power control system based on the flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console.

[0116] The grid-side rectifier is controlled in constant power mode;

[0117] A four-quadrant DC / DC converter is used to control the waveform of the current in the demagnetizing coil, while limiting the power of the demagnetizing coil.

[0118] The flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil. The outer loop uses the DC voltage of the converter as the control target, while the inner loop controls the AC current output of the converter.

[0119] The bidirectional DC / DC converter is used to maintain a constant DC bus voltage, and adopts a control mode of DC voltage outer loop and current inner loop;

[0120] The centralized control console is responsible for monitoring the status of different converters and issuing control commands to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter.

[0121] Reference Figure 2 , Figure 2 This is a block diagram of the grid-side rectifier control in an embodiment of the present invention.

[0122] The grid-side rectifier divides the power command issued by the central control console by 1.5 times the magnitude of the grid voltage to obtain the command value i of the d-axis current loop. dref Command value i for the q-axis current loop qref Set to 0;

[0123] After rotating coordinate transformation, the grid current yields the feedback values ​​i of the d-axis and q-axis currents. d and i q ;

[0124] Command value i for d-axis current loop dref and the feedback value i of the d-axis current d The error, after passing through the first PI controller, is superimposed with the d-axis component u of the grid voltage. gd and the d-axis decoupling component i of the output filter q ω0L, to obtain the d-axis modulation voltage u d Where ω0 is the fundamental angular frequency of the grid voltage, and L is the value of the filter inductance;

[0125]

[0126] in, Indicates the first PI controller, k p1 and k i1 These represent the proportional and integral parameters of the first PI controller, respectively.

[0127] Command value i for q-axis current loop qref and the feedback value i of the q-axis current q The error, after passing through the second PI controller, is superimposed with the q-axis component u of the grid voltage. gq and the q-axis decoupling component i of the output filter d ω0L, to obtain the q-axis modulation voltage u q ;

[0128]

[0129] in, Indicates the second PI controller, k p2 and k i2 These represent the proportional and integral parameters of the second PI controller, respectively.

[0130] Modulation voltage u d and u q The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

[0131] The phases of the rotating coordinate transformation and the inverse rotating coordinate transformation are obtained by phase-locking the grid voltage.

[0132] Reference Figure 3 , Figure 3 This is a block diagram of a four-quadrant DC / DC converter control in an embodiment of the present invention.

[0133] In a four-quadrant DC / DC converter, the specific method for controlling the waveform of the current in the demagnetizing coil is as follows:

[0134] Pulse current command i dcref The output current i of the four-quadrant DC / DC converter sampled by a current sensor dc The error is processed by the third PI controller to obtain the output of the current closed-loop control;

[0135] Multiply the power of the demagnetizing coil by the reciprocal of its maximum power, K, to obtain the per-unit value x of the demagnetizing coil's power.

[0136] The output of the current closed-loop control is multiplied by 1-x 2The duty cycle d of the four-quadrant DC / DC converter is obtained; then the switching devices of the four-quadrant DC / DC converter are controlled to realize the current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

[0137]

[0138] in, Indicates the third PI controller, k p3 and k i3 These represent the proportional and integral parameters of the third PI controller, respectively.

[0139] Reference Figure 4 , Figure 4 This is a control block diagram of the flywheel-side converter in an embodiment of the present invention.

[0140] The flywheel-side converter charges and discharges the flywheel motor based on the power of the demagnetizing coil. The specific method is as follows:

[0141] In the rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted. The voltage outer loop control is implemented in the centralized control console, and the current inner loop control is implemented on the flywheel-side converter.

[0142] The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the given DC voltage command value U... dcrefk DC voltage U of the flywheel-side converter dck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value i of the q-axis current inner loop. qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value i of the d-axis current inner loop. drefk Set to 0;

[0143]

[0144] in, This indicates the fourth PI controller, k p4 and k i4 These represent the proportional and integral parameters of the fourth PI controller, respectively.

[0145] The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​i of the d-axis and q-axis currents. dk and i qk ;

[0146] Command value i of the d-axis current inner loop drefk and the feedback value i of the d-axis current dkThe error, after passing through the fifth PI controller, yields the d-axis modulated voltage u. dk ;

[0147]

[0148] in, This indicates the fifth PI controller, k p5 and k i5 These represent the proportional and integral parameters of the fifth PI controller, respectively.

[0149] Command value i for the inner loop of the q-axis current qrefk and the feedback value i of the q-axis current qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage u. qk ;

[0150]

[0151] in, This indicates the sixth PI controller, k p6 and k i6 These represent the proportional and integral parameters of the sixth PI controller, respectively.

[0152] Modulation voltage u dk and u qk The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

[0153] The phases of the rotational coordinate transformation and the inverse rotational coordinate transformation are obtained through the position sensor of the flywheel motor.

[0154] Reference Figure 5 , Figure 5 This is a control block diagram of the bidirectional DC / DC converter in an embodiment of the present invention. It employs a DC voltage outer loop control mode and a current inner loop control mode. The DC voltage outer loop control is implemented in a centralized control console, while the DC current inner loop control is implemented on the bidirectional DC / DC converter.

[0155] The voltage outer loop control mode is as follows: the DC bus voltage of the demagnetizing power supply is used as the control target, and the given DC voltage command value U... dcref With the DC voltage U of the bidirectional DC / DC converter dc The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value i of the inner current loop. dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage.

[0156]

[0157] in, This indicates the seventh PI controller, k p7 and k i7 These represent the proportional and integral parameters of the seventh PI controller, respectively.

[0158] The current inner loop control mode is as follows: the command value i of the current inner loop is... dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle d of the bidirectional DC / DC converter through the eighth PI controller. k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage.

[0159]

[0160] in, This indicates the eighth PI controller, k p8 and k i8 These represent the proportional and integral parameters of the eighth PI controller, respectively.

[0161] Example 4

[0162] like Figure 1 As shown, the demagnetizing power control system based on the flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console.

[0163] The AC side of the grid-side rectifier is connected to the power grid via a transformer, while the DC side is a DC bus.

[0164] One end of the four-quadrant DC / DC converter and one end of the bidirectional DC / DC converter are both connected to the DC bus.

[0165] The other end of the four-quadrant DC / DC converter is connected to the demagnetizing coil;

[0166] The flywheel motor is connected to the other end of the bidirectional DC / DC converter via a flywheel-side converter.

[0167] The centralized control console is connected to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, respectively. It is used to monitor the status of the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, and to issue power commands to the grid-side rectifier, pulse current commands to the four-quadrant DC / DC converter, current inner loop commands to the flywheel-side converter, and current inner loop commands to the bidirectional DC / DC converter.

[0168] The grid-side rectifier is used to perform constant power mode control based on the power commands issued by the central control console.

[0169] A four-quadrant DC / DC converter is used to control the current waveform of the demagnetizing coil and limit the power of the demagnetizing coil.

[0170] The flywheel-side converter is used to charge and discharge the flywheel motor according to the power of the demagnetizing coil;

[0171] A bidirectional DC / DC converter is used to maintain a constant DC bus voltage.

[0172] Figure 6 This is a schematic diagram of the electronic device structure provided in an embodiment of the present invention, with reference to... Figure 6 The electronic device may include: a processor 201, a communication interface 202, a memory 203, and a communication bus 204, wherein the processor 201, the communication interface 202, and the memory 203 communicate with each other through the communication bus 204. The processor 201 can call the logic instructions in the memory 203 to execute the following method: (1) The grid-side rectifier adopts constant power mode control:

[0173] Based on the power command issued by the central control console to the grid-side rectifier, calculate the command value i of the d-axis current loop. dref Command value i for the q-axis current loop qref Set to 0;

[0174] After rotating coordinate transformation, the grid current yields the feedback values ​​i of the d-axis and q-axis currents. d and i q ;

[0175] Command value i for d-axis current loop dref and the feedback value i of the d-axis current d The error, after passing through the first PI controller, is superimposed with the d-axis component u of the grid voltage. gd and the d-axis decoupling component i of the output filter q ω0L, to obtain the d-axis modulation voltage u d Where ω0 is the fundamental angular frequency of the grid voltage, and L is the value of the filter inductance;

[0176] Command value i for q-axis current loop qref and the feedback value i of the q-axis current q The error, after passing through the second PI controller, is superimposed with the q-axis component u of the grid voltage. gq and the q-axis decoupling component i of the output filter d ω0L, to obtain the q-axis modulation voltage u q;

[0177] Modulation voltage u d and u q The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

[0178] (2) Waveform of the current controlling the demagnetizing coil of the four-quadrant DC / DC converter:

[0179] Pulse current command i dcref The output current i of the four-quadrant DC / DC converter sampled by a current sensor dc The error is processed by the third PI controller to obtain the output of the current closed-loop control;

[0180] Multiply the power of the demagnetizing coil by the reciprocal of its maximum power, K, to obtain the per-unit value x of the demagnetizing coil's power.

[0181] The output of the current closed-loop control is multiplied by 1-x 2 The duty cycle d of the four-quadrant DC / DC converter is obtained; then the switching devices of the four-quadrant DC / DC converter are controlled to realize the current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

[0182] (3) The flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil:

[0183] In a rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted;

[0184] The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the preset DC voltage command value U of the flywheel-side converter in the central control console is used. dcrefk DC voltage U of the flywheel-side converter dck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value i of the q-axis current inner loop. qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value i of the d-axis current inner loop. drefk Set to 0;

[0185] The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​i of the d-axis and q-axis currents. dk and i qk ;

[0186] Command value i of the d-axis current inner loop drefk and the feedback value i of the d-axis currentdk The error, after passing through the fifth PI controller, yields the d-axis modulated voltage u. dk ;

[0187] Command value i for the inner loop of the q-axis current qrefk and the feedback value i of the q-axis current qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage u. qk ;

[0188] Modulation voltage u dk and u qk The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

[0189] (4) The bidirectional DC / DC converter maintains a constant DC bus voltage:

[0190] It adopts a DC voltage outer loop control mode and a current inner loop control mode;

[0191] The voltage outer loop control mode is as follows: the demagnetizing power supply DC bus voltage is the control target, and the preset demagnetizing power supply DC bus voltage command value U in the central control console is used. dcref With the DC voltage U of the bidirectional DC / DC converter d c The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value i of the inner current loop. dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage.

[0192] The current inner loop control mode is as follows: the command value i of the current inner loop is... dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle d of the bidirectional DC / DC converter through the eighth PI controller. k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage.

[0193] Furthermore, the logical instructions in the aforementioned memory 203 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0194] On the other hand, embodiments of the present invention also provide a non-transient computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a demagnetizing power supply control method based on a flywheel energy storage device provided in the above embodiments, including, for example,: (1) the grid-side rectifier adopts constant power mode control:

[0195] Based on the power command issued by the central control console to the grid-side rectifier, calculate the command value i of the d-axis current loop. dref Command value i for the q-axis current loop qref Set to 0;

[0196] After rotating coordinate transformation, the grid current yields the feedback values ​​i of the d-axis and q-axis currents. d and i q ;

[0197] Command value i for d-axis current loop dref and the feedback value i of the d-axis current d The error, after passing through the first PI controller, is superimposed with the d-axis component u of the grid voltage. gd and the d-axis decoupling component i of the output filter q ω0L, to obtain the d-axis modulation voltage u d Where ω0 is the fundamental angular frequency of the grid voltage, and L is the value of the filter inductance;

[0198] Command value i for q-axis current loop qref and the feedback value i of the q-axis current q The error, after passing through the second PI controller, is superimposed with the q-axis component u of the grid voltage. gq and the q-axis decoupling component i of the output filter d ω0L, to obtain the q-axis modulation voltage u q ;

[0199] Modulation voltage u d and u q The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

[0200] (2) Waveform of the current controlling the demagnetizing coil of the four-quadrant DC / DC converter:

[0201] Pulse current command i dcref The output current i of the four-quadrant DC / DC converter sampled by a current sensor dc The error is processed by the third PI controller to obtain the output of the current closed-loop control;

[0202] Multiply the power of the demagnetizing coil by the reciprocal of its maximum power, K, to obtain the per-unit value x of the demagnetizing coil's power.

[0203] The output of the current closed-loop control is multiplied by 1-x 2 The duty cycle d of the four-quadrant DC / DC converter is obtained; then the switching devices of the four-quadrant DC / DC converter are controlled to realize the current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

[0204] (3) The flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil:

[0205] In a rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted;

[0206] The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the preset DC voltage command value U of the flywheel-side converter in the central control console is used. dcrefk DC voltage U of the flywheel-side converter dck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value i of the q-axis current inner loop. qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value i of the d-axis current inner loop. drefk Set to 0;

[0207] The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​i of the d-axis and q-axis currents. dk and i qk ;

[0208] Command value i of the d-axis current inner loop drefk and the feedback value i of the d-axis current dkThe error, after passing through the fifth PI controller, yields the d-axis modulated voltage u. dk ;

[0209] Command value i for the inner loop of the q-axis current qrefk and the feedback value i of the q-axis current qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage u. qk ;

[0210] Modulation voltage u dk and u qk The three-phase AC modulation voltage u is obtained after inverse coordinate transformation. abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

[0211] (4) The bidirectional DC / DC converter maintains a constant DC bus voltage:

[0212] It adopts a DC voltage outer loop control mode and a current inner loop control mode;

[0213] The voltage outer loop control mode is as follows: the demagnetizing power supply DC bus voltage is the control target, and the preset demagnetizing power supply DC bus voltage command value U in the central control console is used. dcref With the DC voltage U of the bidirectional DC / DC converter d c The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value i of the inner current loop. dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage.

[0214] The current inner loop control mode is as follows: the command value i of the current inner loop is... dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle d of the bidirectional DC / DC converter through the eighth PI controller. k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage. The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0215] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0216] Application Examples

[0217] Assume the demagnetizing coil has a resistance of 0.11Ω and an inductance of 0.3H. Using... Figure 1 The demagnetizing main power supply system topology based on flywheel energy storage is shown. The transformer turns ratio is 10kV / 0.69kV. The grid-side rectifier uses a bridge PWM rectifier with a DC-side output voltage of 2500V. The four-quadrant DC / DC converter has an adjustable output voltage between 4 and 2200V and an output current range of 40 to 4500A. Five flywheel energy storage units are connected in parallel to the DC side of the grid-side rectifier. Each flywheel energy storage unit includes a flywheel motor, a flywheel-side rectifier, and a bidirectional DC / DC converter. The flywheel motor output is connected to the flywheel-side rectifier, and then connected to the DC side of the grid-side rectifier via the bidirectional DC / DC converter. The flywheel-side rectifier outputs a DC voltage of 1200V.

[0218] Circuit simulation was performed using Matlab / Simulink. The operating current of the degaussing coil was represented by two alternating pulse waveforms. The positive pulse current amplitude was 4500A, with a 1s pulse to start and a 3s pulse to stop; the negative pulse current amplitude was 4300A, with a 5s pulse to start and a 7s pulse to stop. The simulated current waveform of the degaussing coil is shown below. Figure 7 As shown, the simulated current accuracy is approximately 0.17%, and the rise or fall time of the current during two consecutive operating current pulses is no greater than 1 second, meeting the requirements of the demagnetizing current system. The simulated output power waveform of the flywheel energy storage unit is shown below. Figure 8 As shown, during the demagnetizing coil pulse current off period, the flywheel energy storage unit absorbs power from the grid side for energy storage. During the demagnetizing coil current pulse on period, the flywheel energy storage unit provides pulse power to the coil. Furthermore, after the pulse current is turned off, the flywheel energy storage unit can still absorb the electrical energy stored in the demagnetizing coil. The power simulation waveform on the grid side is shown below. Figure 9 As shown, it can be seen that the power on the grid side remains basically constant during the opening and closing of the demagnetizing coil pulse current, indicating that the pulse current does not cause an impact on the grid. The pulse power generated by the sudden addition and removal of the demagnetizing coil is smoothed out through the flywheel energy storage device.

[0219] In summary, the demagnetizing power supply control method, system, and equipment based on a flywheel energy storage device proposed in this invention can meet the power supply requirements of the demagnetizing coil, and the overall system operation is stable. The advantages of this invention are specifically manifested in:

[0220] (1) The grid-side rectifier is controlled in constant power mode, which greatly improves the stability of the grid. This is especially important for weak grids such as diesel generator sets. In addition, in this mode, the grid can continuously output the maximum allowable power, which can minimize the energy stored in the flywheel and thus reduce the engineering cost of the system.

[0221] (2) The flywheel-side converter charges and discharges the flywheel motor according to the power of the demagnetizing coil. The bidirectional DC / DC converter is used to maintain the constant DC bus voltage. It can effectively suppress the power surge of the working coil during demagnetizing operation, create conditions for the constant power control of the grid-side rectifier, and store the huge energy fed back when the current of the large inductor demagnetizing coil decreases, so that the large current is reduced to zero quickly, meeting the system index of rise and fall time of less than 1s.

[0222] (3) The four-quadrant DC / DC converter is used to control the waveform of the current in the demagnetizing coil and limit the power of the demagnetizing coil, which can effectively reduce the instantaneous power demand of the flywheel energy storage device and further reduce the engineering cost of the system.

[0223] (4) The system has grid-side rectifiers, flywheel-side converters, bidirectional DC / DC converters and four-quadrant DC / DC converters. The multiple converters are closely related in terms of power flow, but their control objectives and modes are different. They achieve decoupling control between each other, which simplifies the system control strategy.

[0224] It should be understood that any parts not described in detail in this specification belong to the prior art.

[0225] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A demagnetizing power supply control method based on a flywheel energy storage device, characterized in that, A demagnetizing power control system based on a flywheel energy storage device is adopted; the demagnetizing power control system based on a flywheel energy storage device includes a grid-side rectifier, a four-quadrant DC / DC converter, a flywheel-side converter, a bidirectional DC / DC converter, and a centralized control console; The AC side of the grid-side rectifier is connected to the power grid via a transformer, while the DC side is a DC bus. One end of the four-quadrant DC / DC converter and one end of the bidirectional DC / DC converter are both connected to the DC bus. The other end of the four-quadrant DC / DC converter is connected to the demagnetizing coil; The flywheel motor is connected to the other end of the bidirectional DC / DC converter via a flywheel-side converter. The centralized control console is connected to the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, respectively. It is used to monitor the status of the grid-side rectifier, four-quadrant DC / DC converter, flywheel-side converter, and bidirectional DC / DC converter, and to issue power commands to the grid-side rectifier, pulse current commands to the four-quadrant DC / DC converter, current inner loop commands to the flywheel-side converter, and current inner loop commands to the bidirectional DC / DC converter. The grid-side rectifier is used to perform constant power mode control based on the power commands issued by the central control console. A four-quadrant DC / DC converter is used to control the current waveform of the demagnetizing coil and limit the power of the demagnetizing coil. The flywheel-side converter is used to charge and discharge the flywheel motor according to the power of the demagnetizing coil; A bidirectional DC / DC converter is used to maintain a constant DC bus voltage; In a four-quadrant DC / DC converter, the specific method for controlling the waveform of the current in the demagnetizing coil is as follows: Pulse current command i dcref The output current of the four-quadrant DC / DC converter is sampled by a current sensor. i dc The error is processed by the third PI controller to obtain the output of the current closed-loop control; The power of the degaussing coil multiplied by the reciprocal of the maximum power of the degaussing coil. K The per-unit value of the demagnetizing coil power is obtained. x ; The output of the current closed-loop control is multiplied by The duty cycle of the four-quadrant DC / DC converter is obtained. d Then, the switching devices of the four-quadrant DC / DC converter are controlled to achieve current waveform control of the demagnetizing coil and limit the power of the demagnetizing coil.

2. The demagnetizing power supply control method based on a flywheel energy storage device according to claim 1, characterized in that, The specific method for constant power mode control of the grid-side rectifier is as follows: Based on the power command issued by the central control console to the grid-side rectifier, calculate the command value of the d-axis current loop. i dref Command value for the q-axis current loop i qref Set to 0; The grid current is transformed using a rotating coordinate system to obtain the feedback values ​​of the d-axis and q-axis currents. i d and i q ; Command value of d-axis current loop i dref Feedback value of d-axis current i d The error, after passing through the first PI controller, is superimposed with the d-axis component of the grid voltage. u gd and the d-axis decoupling component of the output filter i q ω 0 L d-axis modulation voltage is obtained u d ; in, ω 0 represents the fundamental angular frequency of the grid voltage. L This is the value of the filter inductance; Command value of q-axis current loop i qref Feedback value of q-axis current i q The error, after passing through the second PI controller, is superimposed with the q-axis component of the grid voltage. u gq and the q-axis decoupling component of the output filter i d ω 0 L q-axis modulation voltage is obtained u q ; Modulation voltage u d and u q The three-phase AC modulation voltage is obtained after inverse coordinate transformation. u abc Then, the switching devices of the grid-side rectifier are controlled to achieve constant power mode control.

3. The demagnetizing power supply control method based on a flywheel energy storage device according to claim 2, characterized in that, The phases of the rotating coordinate transformation and the inverse rotating coordinate transformation are obtained by phase-locking the grid voltage.

4. The demagnetizing power supply control method based on a flywheel energy storage device according to claim 1, characterized in that, The flywheel-side converter charges and discharges the flywheel motor based on the power of the demagnetizing coil. The specific method is as follows: In a rotating coordinate system, a voltage outer loop control mode and a current inner loop control mode are adopted; The voltage outer loop control mode is as follows: the DC voltage of the flywheel-side converter is used as the control target, and the DC voltage command value of the flywheel-side converter is preset in the central control console. U dcrefk DC voltage of flywheel-side converter U dck The error, after passing through the fourth PI controller, is superimposed with the feedforward current command value of the flywheel-side converter to obtain the command value of the q-axis current inner loop. i qrefk The feedforward current command value of the flywheel-side converter is obtained by dividing the demagnetizing coil power by 1.5 times the AC voltage amplitude of the flywheel-side converter; the command value of the d-axis current inner loop. i drefk Set to 0; The current inner loop control mode is as follows: the sampled flywheel-side converter output AC current is transformed by rotating coordinates to obtain the feedback values ​​of the d-axis and q-axis currents. i dk and i qk ; Command value of d-axis current inner loop i drefk Feedback value of d-axis current i dk The error is processed by the fifth PI controller to obtain the d-axis modulated voltage. u dk ; Command value of q-axis current inner loop i qrefk Feedback value of q-axis current i qk The error is processed by the sixth PI controller to obtain the q-axis modulated voltage. u qk ; Modulation voltage u dk and u qk The three-phase AC modulation voltage is obtained after inverse coordinate transformation. u abck Then, the switching devices of the flywheel-side rectifier are controlled to open and close, thereby enabling the flywheel motor to be charged and discharged according to the power of the demagnetizing coil.

5. The demagnetizing power supply control method based on a flywheel energy storage device according to claim 4, characterized in that, The phases of the rotational and inverse rotational coordinate transformations are obtained through the position sensor of the flywheel motor.

6. The demagnetizing power supply control method based on a flywheel energy storage device according to claim 1, characterized in that, The specific method for maintaining a constant DC bus voltage in a bidirectional DC / DC converter is as follows: It adopts a DC voltage outer loop control mode and a current inner loop control mode; The voltage outer loop control mode is as follows: the DC bus voltage of the demagnetizing power supply is used as the control target, and the preset command value of the DC bus voltage of the demagnetizing power supply in the centralized control console is used. U dcref DC voltage of bidirectional DC / DC converter U dc The error, after passing through the seventh PI controller, is superimposed with the feedforward current command value of the bidirectional DC / DC converter to obtain the command value of the inner current loop. i dcrefk The feedforward current command value of the bidirectional DC / DC converter is obtained by dividing the demagnetizing coil power by the DC bus voltage. The current inner loop control mode is: the command value of the current inner loop. i dcrefk With bidirectional DC / DC converter output current i dck The error is used to obtain the duty cycle of the bidirectional DC / DC converter through the eighth PI controller. d k Then, the switching devices of the bidirectional DC / DC converter are controlled to maintain a constant DC bus voltage.

7. A demagnetizing power supply control system based on a flywheel energy storage device, employing the demagnetizing power supply control method based on a flywheel energy storage device as described in any one of claims 1 to 6.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the demagnetizing power supply control method based on a flywheel energy storage device as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the demagnetizing power supply control method based on a flywheel energy storage device as described in any one of claims 1 to 6.

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