A method, device, equipment and medium for compensating impact power of fusion power source

Abstract

The present invention discloses a compensation method, device, equipment and medium for the impact power of a fusion power supply, performs fusion power characteristic analysis on the fusion power supply, determines the power characteristic; determines the impact power compensation topology structure composed of a DC filter inductor and a cascade H-bridge topology containing a lithium-ion capacitor in series according to the power characteristic; determines the parameter value of the DC filter inductor in the impact power compensation topology structure; performs discrete dual synchronous coordinate phase-locked loop control according to the impact power compensation topology structure; performs current inner loop decoupling control according to the impact power compensation topology structure; performs power outer loop compensation control according to the impact power compensation topology structure, and performs oscillation detection on the fusion power supply; when there is no oscillation in the fusion power supply, the controlled impact power compensation topology structure is used to perform synchronous compensation of impact active power and impact reactive power. The present application introduces energy storage technology to cope with high-power impacts, realizes active impact power compensation, and improves the stability of the fusion power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a method, device, equipment and medium for compensating the impulse power of a fusion power supply. Background Art

[0002] Magnetic confinement fusion is developing towards long pulse and high confinement modes. The Experimental Advanced Superconducting Tokamak (EAST) has achieved 403 seconds of stable operation in H mode. As a result, the proportion of different power electronic devices and pulsed power devices in the fusion system has continued to increase, and the dynamic characteristics of the system have changed significantly. The interaction between various types of equipment has further intensified, resulting in violent power oscillations, which has brought great difficulties to solving the problem of synchronous stability of the power system. Summary of the invention

[0003] In order to solve the above problems, the present invention proposes a method, device, equipment and medium for compensating the impulse power of a fusion power source, which can realize active impulse power compensation and improve the stability of the fusion power source.

[0004] An embodiment of the present invention provides a method for compensating the impact power of a fusion power source, the method comprising:

[0005] Analyze the fusion power characteristics of the fusion power source and determine the power characteristics;

[0006] Determine, according to the power characteristics, a surge power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor connected in series;

[0007] Determining a parameter value of a DC filter inductor in the impulse power compensation topology;

[0008] Discrete dual synchronous coordinate phase-locked loop control is performed according to the impulse power compensation topology;

[0009] Performing current inner loop decoupling control according to the impact power compensation topology structure;

[0010] Performing power outer loop compensation control according to the impulse power compensation topology structure, and performing oscillation detection on the fusion power supply;

[0011] When the fusion power source does not have oscillation, the controlled impulse power compensation topology structure is used to perform synchronous compensation of impulse active power and impulse reactive power.

[0012] Preferably, the method further comprises:

[0013] When oscillation occurs in the fusion power source, a ramp link is added to the power outer-loop compensation control through a preset ramp function, the power outer-loop compensation control is re-performed according to the impact power compensation topology, and the fusion power source is re-detected for oscillation until there is no oscillation in the fusion power source.

[0014] Preferably, the determining, according to the power characteristics, of an impulse power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor in series specifically includes:

[0015] Determine the parameter value of the lithium ion capacitor according to the discharge characteristic and the peak-to-average ratio characteristic in the power characteristic;

[0016] Determine the parameter value of the cascaded H-bridge topology according to the 100M high power characteristic in the power characteristic;

[0017] The lithium-ion capacitor is connected to the DC side of the H-bridge power module of the cascaded H-bridge topology, and the DC filter inductor is connected in series with the cascaded H-bridge topology to obtain the impact power compensation topology structure.

[0018] As a preferred solution, determining the parameter value of the DC filter inductor in the impulse power compensation topology structure includes:

[0019] Calculating a DC side current flowing into a DC side of an H-bridge power module of the cascaded H-bridge topology;

[0020] Decomposing the DC side current to determine a first component current of the secondary frequency-doubled current in the lithium-ion capacitor branch and a second component current in the H-bridge capacitor branch;

[0021] Determine a branch current flowing through the lithium-ion capacitor branch by using the superposition theorem based on the first component current and the second component current;

[0022] Calculating the current ripple rate of the lithium ion capacitor branch and the voltage ripple rate of the H-bridge DC side capacitor when the lithium ion capacitor provides active power according to the branch current;

[0023] The parameter value of the DC filter inductor is calculated according to the current ripple rate and the voltage ripple rate.

[0024] Preferably, discrete dual synchronous coordinate phase-locked loop control is performed according to the impulse power compensation topology, specifically including:

[0025] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0026] Decomposing the grid voltage in the impulse power compensation topology into a positive sequence vector and a negative sequence vector in the dual synchronous coordinate system;

[0027] A dual synchronous coordinate decoupling network is used to convert the positive sequence vector and the negative sequence vector into a time domain expression;

[0028] The positive sequence vector and the negative sequence vector are separated and phase-locked controlled according to the time domain expression.

[0029] Preferably, the current inner loop decoupling control is performed according to the impact power compensation topology structure, including:

[0030] Converting the active power demand and reactive power demand of the fusion power source into active reference current and reactive reference current;

[0031] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0032] Decomposing the active reference current and the reactive reference current in the impulse power compensation topology into corresponding positive sequence vectors and negative sequence vectors respectively in the dual synchronous coordinate system;

[0033] The obtained positive sequence vector and negative sequence vector are transformed into time domain expressions by using a dual synchronous coordinate decoupling network to obtain the reference current of positive and negative sequence decoupling control.

[0034] Feedforward decoupling and PI regulator are used for regulation to generate positive and negative sequence voltage modulation signals in a dq synchronous rotating coordinate system, which are then modulated through a modulation link after coordinate transformation.

[0035] Preferably, the power outer loop compensation control is performed according to the impact power compensation topology structure, including:

[0036] Calculating the active power and reactive power of the impulse power compensation topology structure according to the instantaneous power calculation theory;

[0037] Determine a first transfer function of direct power outer loop control according to the active power and the reactive power;

[0038] Determine a second transfer function of the power and current dual closed-loop control according to the first transfer function and the transfer function of the first-order low-pass filter;

[0039] Power outer loop compensation control is performed according to the second transfer function.

[0040] The embodiment of the present invention further provides a fusion power source impulse power compensation device, the device comprising:

[0041] A characteristic analysis module is used to analyze the fusion power characteristics of the fusion power source and determine the power characteristics;

[0042] A topology module, used for determining, according to the power characteristics, an impulse power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor in series;

[0043] An inductance analysis module, used to determine the parameter value of the DC filter inductance in the impulse power compensation topology;

[0044] A phase-locked loop control module, used for performing discrete dual-synchronous coordinate phase-locked loop control according to the impulse power compensation topology;

[0045] A decoupling control module, used for performing current inner loop decoupling control according to the impact power compensation topology structure;

[0046] A compensation control module, used for performing power outer loop compensation control according to the impulse power compensation topology structure and performing oscillation detection on the fusion power supply;

[0047] The compensation module is used for synchronously compensating the impact active power and the impact reactive power by using the controlled impact power compensation topology when the fusion power source does not have oscillation.

[0048] Preferably, the device further comprises a ramp module, for:

[0049] When oscillation occurs in the fusion power source, a ramp link is added to the power outer-loop compensation control through a preset ramp function, the power outer-loop compensation control is re-performed according to the impact power compensation topology, and the fusion power source is re-detected for oscillation until there is no oscillation in the fusion power source.

[0050] Preferably, the topology module is specifically used for:

[0051] Determine the parameter value of the lithium ion capacitor according to the discharge characteristic and the peak-to-average ratio characteristic in the power characteristic;

[0052] Determine the parameter value of the cascaded H-bridge topology according to the 100M high power characteristic in the power characteristic;

[0053] The lithium-ion capacitor is connected to the DC side of the H-bridge power module of the cascaded H-bridge topology, and the DC filter inductor is connected in series with the cascaded H-bridge topology to obtain the impact power compensation topology structure.

[0054] Preferably, the inductance analysis module is specifically used for:

[0055] Calculating a DC side current flowing into a DC side of an H-bridge power module of the cascaded H-bridge topology;

[0056] Decomposing the DC side current to determine a first component current of the secondary frequency-doubled current in the lithium-ion capacitor branch and a second component current in the H-bridge capacitor branch;

[0057] Determine a branch current flowing through the lithium-ion capacitor branch by using the superposition theorem based on the first component current and the second component current;

[0058] Calculating the current ripple rate of the lithium ion capacitor branch and the voltage ripple rate of the H-bridge DC side capacitor when the lithium ion capacitor provides active power according to the branch current;

[0059] The parameter value of the DC filter inductor is calculated according to the current ripple rate and the voltage ripple rate.

[0060] Preferably, the phase-locked loop control module is specifically used for:

[0061] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0062] Decomposing the grid voltage in the impulse power compensation topology into a positive sequence vector and a negative sequence vector in the dual synchronous coordinate system;

[0063] A dual synchronous coordinate decoupling network is used to convert the positive sequence vector and the negative sequence vector into a time domain expression;

[0064] The positive sequence vector and the negative sequence vector are separated and phase-locked controlled according to the time domain expression.

[0065] Preferably, the decoupling control module is specifically used for:

[0066] Converting the active power demand and reactive power demand of the fusion power source into active reference current and reactive reference current;

[0067] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0068] Decomposing the active reference current and the reactive reference current in the impulse power compensation topology into corresponding positive sequence vectors and negative sequence vectors respectively in the dual synchronous coordinate system;

[0069] The obtained positive sequence vector and negative sequence vector are transformed into time domain expressions by using a dual synchronous coordinate decoupling network to obtain the reference current of positive and negative sequence decoupling control.

[0070] Feedforward decoupling and PI regulator are used for regulation to generate positive and negative sequence voltage modulation signals in a dq synchronous rotating coordinate system, which are then modulated through a modulation link after coordinate transformation.

[0071] Preferably, the compensation control module is specifically used for:

[0072] Calculating the active power and reactive power of the impulse power compensation topology structure according to the instantaneous power calculation theory;

[0073] Determine a first transfer function of direct power outer loop control according to the active power and the reactive power;

[0074] Determine a second transfer function of the power and current dual closed-loop control according to the first transfer function and the transfer function of the first-order low-pass filter;

[0075] Power outer loop compensation control is performed according to the second transfer function.

[0076] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, and when the processor executes the computer program, it implements the method for compensating the impact power of a fusion power source as described in any one of the above embodiments.

[0077] Another embodiment of the present invention provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the method for compensating the impact power of a fusion power source as described in any one of the above embodiments.

[0078] The present invention provides a method, device, equipment and medium for compensating the impact power of a fusion power supply. The method analyzes the fusion power characteristics of the fusion power supply to determine the power characteristics; determines the impact power compensation topology structure composed of a DC filter inductor and a cascaded H-bridge topology containing a lithium-ion capacitor in series according to the power characteristics; determines the parameter value of the DC filter inductor in the impact power compensation topology structure; performs discrete dual synchronous coordinate phase-locked loop control according to the impact power compensation topology structure; performs current inner loop decoupling control according to the impact power compensation topology structure; performs power outer loop compensation control according to the impact power compensation topology structure, and performs oscillation detection on the fusion power supply; when there is no oscillation in the fusion power supply, the controlled impact power compensation topology structure is used to perform synchronous compensation of impact active power and impact reactive power. The present application scheme introduces energy storage technology to cope with high-power impacts in magnetic confinement fusion systems, can realize active impact power compensation, and improve the stability of fusion power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1 It is a flow chart of a method for compensating impulse power of a fusion power supply provided by an embodiment of the present invention;

[0080] Figure 2 It is another schematic flow chart of a method for compensating the impact power of a fusion power supply provided by an embodiment of the present invention;

[0081] Figure 3 is a schematic diagram of a curve of power requirement-time of a fusion power source provided by an embodiment of the present invention;

[0082] Figure 4 It is a schematic diagram of the principle of the impulse power compensation topology structure provided by an embodiment of the present invention;

[0083] Figure 5 Schematic diagram of the principle of power outer loop compensation control provided by an embodiment of the present invention;

[0084] Figure 6 is a schematic diagram of a high-rate discharge curve of a lithium-ion capacitor provided by an embodiment of the present invention;

[0085] Figure 7 It is a structural schematic diagram of a fusion power source impulse power compensation device provided by an embodiment of the present invention;

[0086] Figure 8 It is a structural diagram of a terminal device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0087] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0088] In response to the above-mentioned impact power problem, the existing technology widely uses static VAR compensators, generators and synchronous series compensators to suppress power impacts. Static synchronous compensators are the most advanced reactive compensation devices, with the advantages of fast response speed and high energy conversion efficiency. However, for fusion power sources involving bidirectional active power flow, the commonly used solutions can only indirectly affect the active power of the system through voltage compensation, and its support capacity and scope are quite limited.

[0089] On the other hand, fusion power sources need to balance multiple specific requirements for pulse power compensation of fusion devices, including single discharge duration of minutes, response of milliseconds, and high ratio of pulse power to required capacity. Lithium-ion capacitors (LICs) with high rate discharge performance, good safety and long life can meet the above requirements at the same time, overcoming the shortcomings of widely used energy storage components such as lithium-ion batteries and supercapacitors.

[0090] With the improvement of the operating parameters of the fusion power system and the millisecond-level control of plasma, the pulse power forms a strong nonlinear coupling interaction with power electronic equipment and the power grid. The deep-seated compatibility issues between the equipment are becoming increasingly prominent, which can easily lead to power shocks and resonance phenomena, causing equipment damage and experimental failure, and threatening the long-pulse stable operation of the fusion device.

[0091] In order to make up for this deficiency, energy storage technology is one of the most promising solutions. It can provide fast power support, power quality assurance and emergency power supply for equipment, overcome the shortcomings of short-term operation of traditional pulse motors, and realize active impact power compensation. This application provides a compensation method for impact power of fusion power supply, see Figure 1 , is a flow chart of a method for compensating impulse power of a fusion power source provided by an embodiment of the present invention, the method comprising steps S1 to S7:

[0092] S1, analyzing the fusion power characteristics of the fusion power source to determine the power characteristics;

[0093] S2, determining an impact power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor in series according to the power characteristics;

[0094] S3, determining a parameter value of a DC filter inductor in the impulse power compensation topology structure;

[0095] S4, performing discrete dual synchronous coordinate phase-locked loop control according to the impact power compensation topology structure;

[0096] S5, performing current inner loop decoupling control according to the impact power compensation topology structure;

[0097] S6, performing power outer loop compensation control according to the impact power compensation topology structure, and performing oscillation detection on the fusion power supply;

[0098] S7, when there is no oscillation in the fusion power source, a controlled impulse power compensation topology structure is used to perform synchronous compensation of impulse active power and impulse reactive power.

[0099] When this embodiment is implemented, see Figure 2 , is another flow chart of the method for compensating the impact power of a fusion power source provided in an embodiment of the present invention.

[0100] During the specific implementation of this case, the power characteristics are determined based on the analysis of the fusion power characteristics of the fusion power source.

[0101] According to the determined power characteristics, an impact power compensation topology is constructed.

[0102] In view of the single discharge duration of minutes, millisecond-level rapid response and high peak-to-average ratio characteristics of fusion power source impact power, lithium-ion capacitors (LIC) with high energy storage density, good safety and long life can meet the above requirements at the same time and overcome the shortcomings of lithium iron phosphate batteries and supercapacitors.

[0103] This application combines the cascaded H-bridge topology structure and proposes a method for compensating the impact power of the cascaded high-rate LIC, which can effectively support the active and reactive impacts of the high-voltage and large-capacity power supply system at the same time. In addition, a DC filter inductor is used between the cascaded H-bridge topology and the LIC, and the parameter value of the DC filter inductor in the impact power compensation topology structure is determined to avoid current overshoot affecting the life of the energy storage element.

[0104] An impact power compensation control method is performed based on an impact power compensation topology structure, specifically: a discrete dual synchronous coordinate phase-locked loop is used to achieve accurate phase locking when the grid voltage is unbalanced;

[0105] The current inner loop decoupling control is adopted to realize the decoupling control of the active and reactive currents output by the cascade energy storage device;

[0106] Using power outer loop synchronous control, for the cascade energy storage device, the difference from the chain STATCOM is that during the operation of the device, the energy storage unit must provide active power by discharging. The discharge process will cause the voltage of the DC side sub-module to drop. At this time, the voltage outer loop control effect will be greatly reduced. Therefore, this paper proposes to use the power outer loop control method to achieve further control of active and reactive currents.

[0107] When the fusion power source does not have oscillation, the controlled impulse power compensation topology structure is used to perform synchronous compensation of impulse active power and impulse reactive power.

[0108] This application innovatively proposes a cascaded high-rate LIC energy storage solution, and its innovations are as follows: 1) Introducing energy storage technology to cope with high-power impacts in magnetic confinement fusion systems; 2) Based on the special characteristics of high power, low energy, and rapid response of fusion power sources, high-rate LIC energy storage elements are used, which is innovative in the fusion field; 3) Based on high-power scenarios, a cascaded high-rate LIC energy storage is proposed, which is advanced in the fusion field and even the entire industrial field.

[0109] In another embodiment provided by the present invention, the method further includes:

[0110] When oscillation occurs in the fusion power source, a ramp link is added to the power outer-loop compensation control through a preset ramp function, the power outer-loop compensation control is re-performed according to the impact power compensation topology, and the fusion power source is re-detected for oscillation until there is no oscillation in the fusion power source.

[0111] When this embodiment is implemented, see Figure 2 When the system oscillates, a ramp link is added to the power outer loop compensation control through a preset ramp function, the power outer loop compensation control is re-performed according to the impact power compensation topology structure, and the fusion power supply is re-detected for oscillation until there is no oscillation in the fusion power supply.

[0112] Through oscillation detection, active compensation of impact active power and reactive power is achieved, providing a basis for fusion power sources to reduce grid impact and improve dynamic stability performance.

[0113] In another embodiment provided by the present invention, the step S2 specifically includes:

[0114] Determine the parameter value of the lithium ion capacitor according to the discharge characteristic and the peak-to-average ratio characteristic in the power characteristic;

[0115] Determine the parameter value of the cascaded H-bridge topology according to the 100M high power characteristic in the power characteristic;

[0116] The lithium-ion capacitor is connected to the DC side of the H-bridge power module of the cascaded H-bridge topology, and the DC filter inductor is connected in series with the cascaded H-bridge topology to obtain the impact power compensation topology structure.

[0117] In the specific implementation of this embodiment, according to the analysis of the power characteristics of the magnetic confinement fusion power source, see Figure 3 , is a schematic diagram of the power demand-time curve of the fusion power supply provided by an embodiment of the present invention. It can be seen from the figure that the fusion power supply system presents the characteristics of a high peak-to-average power ratio (the ratio of the impact peak power to the average power), and the duration of the fusion impact power is more than a minute. Therefore, energy storage technology that takes into account both long time and high rate is an effective solution to the power impact problem of fusion power supply systems. Lithium-ion capacitors use "pseudocapacitor + microporous lithium storage" technology, combining all the advantages of lithium-ion batteries and supercapacitors. It has ultra-long charging times, the best match between energy and power density, and still has the best performance at ultra-low temperatures. Therefore, lithium-ion capacitors are very suitable for future fusion reactor long pulse discharge scenarios, and are potential components for solving high-amplitude power impacts.

[0118] See also Figure 2 , when performing a cascaded lithium-ion capacitor impact supplement topology, determining the lithium-ion capacitor according to the minute-level discharge characteristic and the high peak-to-average ratio characteristic in the power characteristic;

[0119] Determine the parameter value of the cascaded H-bridge topology according to the 100M high power characteristic in the power characteristic;

[0120] At present, most mature solutions for grid-connected converters of energy storage systems are two-level / three-level converters. However, considering the large-capacity energy storage of pulse power required for the operation of fusion devices, multiple machines need to be connected in parallel, which brings stability problems, poor response performance, and complex coordinated control. Therefore, the high-voltage cascade H-bridge structure is an effective way to solve the above problems. Not only that, it can also effectively compensate for the impact reactive power through the output control of reactive current. The topological structure of the cascade high-rate LIC impact power compensation method.

[0121] The lithium-ion capacitor is connected to the DC side of the H-bridge power module of the cascaded H-bridge topology, and the DC filter inductor is connected in series with the cascaded H-bridge topology to obtain the impact power compensation topology structure.

[0122] In another embodiment provided by the present invention, the step S3 specifically includes:

[0123] Calculating a DC side current flowing into a DC side of an H-bridge power module of the cascaded H-bridge topology;

[0124] Decomposing the DC side current to determine a first component current of the secondary frequency-doubled current in the lithium-ion capacitor branch and a second component current in the H-bridge capacitor branch;

[0125] Determine a branch current flowing through the lithium-ion capacitor branch by using the superposition theorem based on the first component current and the second component current;

[0126] Calculating the current ripple rate of the lithium ion capacitor branch and the voltage ripple rate of the H-bridge DC side capacitor when the lithium ion capacitor provides active power according to the branch current;

[0127] The parameter value of the DC filter inductor is calculated according to the current ripple rate and the voltage ripple rate.

[0128] When this embodiment is implemented, see Figure 4 , is a schematic diagram of the principle of the impact power compensation topology structure provided by an embodiment of the present invention.

[0129] If the lithium-ion capacitor is directly connected to the DC side of the H-bridge power module, the DC side voltage will be clamped due to the small internal resistance of the lithium-ion capacitor, and the secondary pulsating power of the H-bridge power module will flow into the lithium-ion capacitor module in the form of a double frequency current. Considering the efficiency, economy, and difficulty of implementation of the cascaded energy storage converter, a DC filter inductor is used to suppress the double frequency current.

[0130] Considering high frequency current signals , the DC side current flowing into the DC side of the H bridge can be obtained .

[0131] in, is the DC component, is the secondary pulsation component, is the AC side current, M is the ratio of the maximum effective value of the AC current to the DC current amplitude, φ is the initial phase of the AC current signal, ω is the angular velocity parameter of the AC current signal, and t is the time variable.

[0132] The DC side current of the H-bridge power module can be decomposed into the superposition of DC, secondary and high-frequency current sources. By solving the AC and DC networks respectively, the distribution of DC current and double frequency pulsating current in the LIC branch and the H-bridge capacitor branch can be obtained, and the DC component of the current i can be obtained. E0 =i 0 dc_ai , the component of the double frequency current in the LIC branch and the component in the capacitor branch , respectively:

[0133] ;

[0134] ;

[0135] in, is the impedance of the energy storage unit at the double frequency; is the impedance of the H-bridge DC capacitor at the double frequency; is the double angular frequency; is the equivalent internal resistance of LIC, I m is the AC side current amplitude, L s is the inductance of the DC filter inductor, and C is the capacitance of the DC side capacitor.

[0136] According to the superposition theorem, the current flowing through the LIC branch can be expressed as:

[0137] ;

[0138] When the cascade energy storage device only provides active power, the LIC current ripple rate can be calculated as And the voltage ripple rate of the capacitor on the DC side of the H bridge .

[0139] The current ripple rate , the voltage ripple rate .

[0140] is the average value of the pulsating voltage of the DC side capacitor. The DC filter inductance value L can be obtained by jointly solving the current ripple rate and the voltage ripple rate. s .

[0141] In another embodiment provided by the present invention, the step S4 specifically includes:

[0142] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0143] Decomposing the grid voltage in the impulse power compensation topology into a positive sequence vector and a negative sequence vector in the dual synchronous coordinate system;

[0144] A dual synchronous coordinate decoupling network is used to convert the positive sequence vector and the negative sequence vector into a time domain expression;

[0145] The positive sequence vector and the negative sequence vector are separated and phase-locked controlled according to the time domain expression.

[0146] In the specific implementation of this embodiment, when performing cascade high-rate LIC energy storage impact power compensation control, discrete dual synchronous coordinate phase-locked loop control is first performed, specifically:

[0147] In order to solve the problem of difficult phase locking when the three-phase grid voltage is unbalanced, this paper adopts a discrete dual synchronous reference frame based phase-locked loop (DDSRF-SPLL) method, which can effectively overcome the influence of grid frequency change on the performance of the phase-locked loop. For the three-phase unbalanced system, the dual synchronous reference frame (DSRF) includes two rotating reference frames, namely positive sequence dq +1 Coordinate system and negative sequence dq -1 Coordinate system, the voltage vector V can be expressed in positive sequence and negative sequence under DSRF as:

[0148] ;

[0149] ;

[0150] Among them, in the formula, , and The voltage vector is in the positive sequence dq +1 Coordinate system and negative sequence dq -1 The components of the coordinate system, and The voltage vector is in the positive sequence dq +1 The d-axis component and q-axis component of the coordinate system, and The voltage vector is in the negative sequence dq -1 The d-axis component and q-axis component of the coordinate system, and The voltage vector is in the positive sequence dq +1 Coordinate system and negative sequence dq -1 The magnitude of the coordinate system, The AC voltage signal is in the negative sequence dq -1 The initial phase of the coordinate system, θ is the phase angle of the phase-locked loop output, V αβis the representation of the voltage vector in the αβ coordinate system, is the Park transformation matrix.

[0151] In order to facilitate the introduction of the decoupling network, it is assumed that any voltage vector is and The angular velocity of the rotating shaft rotates, so the voltage vector can be expressed by the positive and negative sequence components as follows:

[0152] ;

[0153] Among them, V αβ is the representation of the voltage vector in the αβ coordinate system, V α and V β are the components of the voltage vector on the α-axis and β-axis respectively, and are the positive and negative sequence components of the voltage vector in the αβ coordinate system, V p , V n are the amplitudes of the positive and negative sequence components of the voltage vector in the αβ coordinate system, and are the initial phase angles of the positive and negative sequence voltages, respectively; p and n are the positive and negative sequence rotation factors, respectively.

[0154] set up is the phase angle of the phase-locked loop output, which must satisfy , the above formula can be expressed as:

[0155] ;

[0156] ;

[0157] in, and are the positive and negative sequence components of the voltage vector in the dq coordinate system, and are the positive sequence components of the voltage vector in the dq coordinate system, and They are the negative sequence components of the voltage vector in the dq coordinate system respectively.

[0158] Figure 4 In, L g is the equivalent inductance of the power grid, U abc is the three-phase voltage of the power grid, I abc is the three-phase current of the power grid, G id (s) is the current loop d-axis transfer function, G iq (s) is the q-axis transfer function of the current loop, G p (s) is the active power control loop transfer function, G q (s) is the transfer function of the reactive power control loop, id and i q They are the d-axis component of the alternating current and the q-axis component of the alternating current respectively.

[0159] For ease of calculation, define the parameter v 1 and v 2 ,make , using a dual synchronous coordinate decoupling network, the time domain expression is obtained:

[0160] ;

[0161] in, , , , They are the d-axis positive sequence reference amplitude, q-axis positive sequence reference amplitude, d-axis negative sequence reference amplitude and q-axis negative sequence reference amplitude of the voltage vector, , , and They are the d-axis positive sequence input voltage value, the q-axis positive sequence input voltage value, the d-axis negative sequence input voltage value and the q-axis negative sequence input voltage value, respectively. , , and They are the d-axis positive-sequence output voltage value, the q-axis positive-sequence output voltage value, the d-axis negative-sequence output voltage value and the q-axis negative-sequence output voltage value respectively.

[0162] The positive and negative sequence components of the grid voltage are separated and phase-locked according to the time domain expression.

[0163] In another embodiment provided by the present invention, the step S4 specifically includes:

[0164] Converting the active power demand and reactive power demand of the fusion power source into active reference current and reactive reference current;

[0165] Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system;

[0166] Decomposing the active reference current and the reactive reference current in the impulse power compensation topology into corresponding positive sequence vectors and negative sequence vectors respectively in the dual synchronous coordinate system;

[0167] The obtained positive sequence vector and negative sequence vector are transformed into time domain expressions by using a dual synchronous coordinate decoupling network to obtain the reference current of positive and negative sequence decoupling control.

[0168] Feedforward decoupling and PI regulator are used for regulation to generate positive and negative sequence voltage modulation signals in a dq synchronous rotating coordinate system, which are then modulated through a modulation link after coordinate transformation.

[0169] In the specific implementation of this embodiment, according to the instantaneous power theory, according to the dq synchronous rotating coordinate system, the active power demand of the power grid is and reactive power demand Convert to active reference current and reactive reference current ;

[0170] ;

[0171] Among them, U sd and U sq They are the d-axis and q-axis components of the grid voltage respectively.

[0172] According to the mathematical model of the converter in the dq synchronous rotating coordinate system established above, it can be known that: due to the active current component output by the converter and reactive current components There is coupling between them, and the two variables cannot be controlled independently. It is necessary to release the coupling between the variables, and the energy storage converter outputs the active current component and reactive current components Affected by the active component of the output voltage and reactive components The influence of the three-phase bridge arm switching function of the converter in the dq synchronous rotating coordinate system and Therefore, the grid current reference active component and reactive component are used as input, and PI regulator is used for control. and , that is, to find the active component of the converter output voltage and reactive components .

[0173] Under conditions such as quenching of fusion superconducting magnets and plasma rupture, the cascaded energy storage converter needs to solve the problem of three-phase voltage imbalance. Under three-phase imbalance, the power grid will introduce negative sequence current. In order to ensure that the cascaded energy storage converter can operate safely and smoothly and compensate for the negative sequence component of the power grid current, this paper adopts positive and negative sequence current decoupling control, so that the converter can control the positive and negative sequence current and achieve three-phase balance.

[0174] The positive and negative sequence current decoupling method based on DSRF is the same as the aforementioned phase-locked loop decoupling method, except that the voltage quantity is converted into the current quantity. The specific derivation process is as follows:

[0175] Let the transfer function of a first-order low-pass filter be ;

[0176] Among them, s is a pull operator.

[0177] For the convenience of analysis, we define parameter i 1 and i 2 ,make ;

[0178] The decoupled network can be expressed as: ;

[0179] in, is the angular velocity parameter of the fundamental frequency AC signal, , , and They are the frequency domain expression of d-axis positive sequence input current, q-axis positive sequence input current, d-axis negative sequence input current, and q-axis negative sequence input current, respectively. , , and They are respectively the d-axis positive sequence output current frequency domain expression, the q-axis positive sequence output current frequency domain expression, the d-axis negative sequence output current frequency domain expression and the q-axis negative sequence output current frequency domain expression, and The parameters i 1 and i 2 The frequency domain expression of .

[0180] The time domain expression is further obtained as: ;

[0181] in, , , and are the reference currents for positive and negative sequence decoupling control, is the angular velocity parameter of the fundamental frequency AC signal, , , and They are the d-axis positive sequence input current value, the q-axis positive sequence input current value, the d-axis negative sequence input current value and the q-axis negative sequence input current value, , , and They are the d-axis positive sequence output current value, the q-axis positive sequence output current value, the d-axis negative sequence output current value, and the q-axis negative sequence output current value respectively.

[0182] After the grid current and voltage are compensated by the cascade energy storage device, the three-phase grid is balanced. According to the instantaneous reactive power theory, the reference current for the positive and negative sequence decoupling control is:

[0183] ;

[0184] In the above formula, , , , is the reference current for positive and negative sequence decoupling control, and They are respectively the positive sequence active and reactive components of the grid voltage. For the positive and negative sequence current decoupling control, feedforward decoupling and PI regulator are also used to adjust, generate positive and negative sequence voltage modulation signals in the dq synchronous rotating coordinate system, and then modulate them through the modulation link after coordinate transformation.

[0185] In another embodiment provided by the present invention, the step S6 specifically includes:

[0186] Calculating the active power and reactive power of the impulse power compensation topology structure according to the instantaneous power calculation theory;

[0187] Determine a first transfer function of direct power outer loop control according to the active power and the reactive power;

[0188] Determine a second transfer function of the power and current dual closed-loop control according to the first transfer function and the transfer function of the first-order low-pass filter;

[0189] Power outer loop compensation control is performed according to the second transfer function.

[0190] In the specific implementation of this embodiment, when performing power synchronization control, for the cascade energy storage device, the difference from the chain STATCOM is that during the operation of the device, the energy storage unit must provide active power by discharging. The discharge process will cause the voltage of the DC side sub-module to drop. At this time, the voltage outer loop control effect will be greatly reduced. Therefore, this article proposes to adopt a power outer loop control method to achieve further control of active and reactive currents.

[0191] When performing DC power control, for a three-phase stationary coordinate system, according to the instantaneous power calculation theory, the calculation formulas for the system active power P and reactive power Q are:

[0192] ;

[0193] in, , and A, B, C three-phase AC voltage, , and They are three-phase alternating currents A, B, and C respectively.

[0194] See also Figure 5, is a schematic diagram of the principle of the power outer loop compensation control provided by an embodiment of the present invention. The figure shows a block diagram of direct power control, firstly three-phase instantaneous power control, then power control, and finally carrier phase shift modulation method CPS-PWM processing. From the figure, it can be deduced that the transfer function of direct power outer loop control is:

[0195] ;

[0196] in, and are the frequency domain expressions of the d-axis and q-axis reference currents, respectively. P and Q are the actual active power and reactive power values, respectively. and are the PI parameters of the d-axis power control loop, and are the PI parameters of the q-axis power control loop respectively.

[0197] Therefore, the power current dual closed-loop control transfer function is obtained as follows:

[0198] ;

[0199] in, is the PI parameter of the current control loop, is the AC / DC modulation ratio of the control system.

[0200] In order to effectively reduce the power oscillation at the start-up moment, a ramp function is added to the power loop to increase the impact compensation power smoothly, thus realizing synchronous and rapid compensation of the active and reactive power of the fusion impact.

[0201] In order to better verify the effectiveness of the discrete dual-synchronous coordinate phase-locked method, the DDSRF phase-locked effect in the ideal power grid and the unbalanced power grid is simulated and compared. The three-phase unbalanced working condition is constructed by setting the three-phase voltage amplitudes to be inconsistent. Even when the three-phase unbalanced phenomenon occurs in the power grid, the discrete dual-synchronous coordinate phase-locked loop can still accurately lock the phase of the power grid, laying the foundation for the precise control of the impact power compensation.

[0202] In order to verify the high-rate output characteristics of the cascaded high-rate lithium-ion capacitor impact power compensation method, a cascaded high-rate energy storage prototype was built. First, a high-rate discharge experiment was carried out on the lithium-ion capacitor. Figure 6 , is a schematic diagram of the high-rate discharge curve of the lithium-ion capacitor provided in an embodiment of the present invention. It can be seen from the figure that the lithium-ion capacitor can last up to 145s under the high-rate discharge condition of 10C. At the same time, the voltage drop is small during this process, and it has good high-rate discharge performance, which is suitable for the needs of high peak-to-average power ratio and minute-level discharge of fusion power sources.

[0203] The solution provided in this application can realize the synchronous compensation of active and reactive power, and achieve a current output of 10C rate, meeting the requirements of fusion power supply.

[0204] In order to solve the problem of high-amplitude power impact introduced by fusion power system, an impact power compensation method of cascaded high-rate lithium-ion capacitor energy storage is proposed. Lithium-ion capacitors are used for active power compensation, combined with cascaded H-bridge topology to achieve rapid support of impact reactive power. In addition, a DC filter inductor is used between the cascaded H-bridge topology and the lithium-ion capacitor energy storage unit to avoid current overshoot affecting the life of the energy storage element; a discrete dual-synchronous coordinate phase-locked loop is used to achieve precise phase locking when the grid voltage is unbalanced; the current inner loop decoupling control is used to achieve decoupling control of the active and reactive currents output by the cascaded energy storage device; the power outer loop synchronous control is used, and when the system oscillates, a ramp link is added to achieve synchronous compensation of impact active power and reactive power. Finally, based on the cascaded high-rate energy storage simulation model and prototype, the experimental results prove that the cascaded high-rate lithium-ion capacitor energy storage can achieve synchronous compensation of impact active and reactive power.

[0205] Another embodiment of the present invention provides a fusion power source impulse power compensation device, see Figure 7 , is a schematic diagram of the structure of a fusion power source impulse power compensation device provided by an embodiment of the present invention, the device comprising:

[0206] A characteristic analysis module is used to analyze the fusion power characteristics of the fusion power source and determine the power characteristics;

[0207] A topology module, used for determining, according to the power characteristics, an impulse power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor in series;

[0208] An inductance analysis module, used to determine the parameter value of the DC filter inductance in the impulse power compensation topology;

[0209] A phase-locked loop control module, used for performing discrete dual-synchronous coordinate phase-locked loop control according to the impulse power compensation topology;

[0210] A decoupling control module, used for performing current inner loop decoupling control according to the impact power compensation topology structure;

[0211] A compensation control module, used for performing power outer loop compensation control according to the impulse power compensation topology structure and performing oscillation detection on the fusion power supply;

[0212] The compensation module is used for synchronously compensating the impact active power and the impact reactive power by using the controlled impact power compensation topology when the fusion power source does not have oscillation.

[0213] The fusion power source impulse power compensation device provided in this embodiment can execute all steps and functions of the fusion power source impulse power compensation method provided in any of the above embodiments, and the specific functions of the device will not be described in detail here.

[0214] See also Figure 8 , is a schematic diagram of the structure of a terminal device provided in an embodiment of the present invention. The terminal device includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a compensation program for the impact power of a fusion power source. When the processor executes the computer program, the steps in each of the above-mentioned embodiments of the method for compensating the impact power of a fusion power source are implemented, such as Figure 1 Alternatively, the processor implements the functions of each module in the above-mentioned device embodiments when executing the computer program.

[0215] Exemplarily, the computer program can be divided into one or more modules, and the one or more modules are stored in the memory and executed by the processor to complete the present invention. The one or more modules can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the device for compensating the impact power of a fusion power source. For example, the computer program can be divided into a detection module, an output power control module, and a window control module. The specific functions of each module have been described in detail in a method for compensating the impact power of a fusion power source provided in any of the above embodiments, and the specific functions of the device will not be repeated here.

[0216] The compensation device for the impact power of a fusion power source may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The compensation device for the impact power of a fusion power source may include, but is not limited to, a processor and a memory. Those skilled in the art may understand that the schematic diagram is only an example of a compensation device for the impact power of a fusion power source, and does not constitute a limitation on a compensation device for the impact power of a fusion power source, and may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the compensation device for the impact power of a fusion power source may also include input and output devices, network access devices, buses, etc.

[0217] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the fusion power supply impulse power compensation device, and uses various interfaces and lines to connect the various parts of the entire fusion power supply impulse power compensation device.

[0218] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the fusion power supply impulse power compensation device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0219] Wherein, if the module integrated in the compensation device for the impact power of a fusion power source is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0220] It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for compensating the impact power of a fusion power source, characterized in that: The method comprises: Analyze the fusion power characteristics of the fusion power source and determine the power characteristics; Determine, according to the power characteristics, a surge power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor connected in series; Determining a parameter value of a DC filter inductor in the impulse power compensation topology; Discrete dual synchronous coordinate phase-locked loop control is performed according to the impulse power compensation topology; Performing current inner loop decoupling control according to the impact power compensation topology structure; Performing power outer loop compensation control according to the impulse power compensation topology structure, and performing oscillation detection on the fusion power supply; When the fusion power source does not have oscillation, the controlled impulse power compensation topology structure is used to perform synchronous compensation of impulse active power and impulse reactive power.

2. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: The method further comprises: When oscillation occurs in the fusion power source, a ramp link is added to the power outer-loop compensation control through a preset ramp function, the power outer-loop compensation control is re-performed according to the impact power compensation topology, and the fusion power source is re-detected for oscillation until there is no oscillation in the fusion power source.

3. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: According to the power characteristics, a surge power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor connected in series is determined, specifically including: Determine the parameter value of the lithium ion capacitor according to the discharge characteristic and the peak-to-average ratio characteristic in the power characteristic; Determine the parameter value of the cascaded H-bridge topology according to the 100M high power characteristic in the power characteristic; The lithium-ion capacitor is connected to the DC side of the H-bridge power module of the cascaded H-bridge topology, and the DC filter inductor is connected in series with the cascaded H-bridge topology to obtain the impact power compensation topology structure.

4. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: Determining the parameter value of the DC filter inductor in the impulse power compensation topology structure includes: Calculating a DC side current flowing into a DC side of an H-bridge power module of the cascaded H-bridge topology; Decomposing the DC side current to determine a first component current of the secondary frequency-doubled current in the lithium-ion capacitor branch and a second component current in the H-bridge capacitor branch; Determine a branch current flowing through the lithium-ion capacitor branch by using the superposition theorem based on the first component current and the second component current; Calculating the current ripple rate of the lithium ion capacitor branch and the voltage ripple rate of the H-bridge DC side capacitor when the lithium ion capacitor provides active power according to the branch current; The parameter value of the DC filter inductor is calculated according to the current ripple rate and the voltage ripple rate.

5. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: According to the impulse power compensation topology structure, discrete dual synchronous coordinate phase-locked loop control is performed, specifically including: Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system; Decomposing the grid voltage in the impulse power compensation topology into a positive sequence vector and a negative sequence vector in the dual synchronous coordinate system; A dual synchronous coordinate decoupling network is used to convert the positive sequence vector and the negative sequence vector into a time domain expression; The positive sequence vector and the negative sequence vector are separated and phase-locked controlled according to the time domain expression.

6. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: The current inner loop decoupling control is performed according to the impact power compensation topology structure, including: Converting the active power demand and reactive power demand of the fusion power source into active reference current and reactive reference current; Construct two rotating coordinate systems of the dual synchronous coordinate system, which are the positive sequence coordinate system and the negative sequence coordinate system; Decomposing the active reference current and the reactive reference current in the impulse power compensation topology into corresponding positive sequence vectors and negative sequence vectors respectively in the dual synchronous coordinate system; The obtained positive sequence vector and negative sequence vector are transformed into time domain expressions by using a dual synchronous coordinate decoupling network, and the reference current of positive and negative sequence decoupling control is obtained. Feedforward decoupling and PI regulator are used for regulation to generate positive and negative sequence voltage modulation signals in a dq synchronous rotating coordinate system, which are then modulated through a modulation link after coordinate transformation.

7. The method for compensating the impact power of a fusion power source according to claim 1, characterized in that: The power outer loop compensation control is performed according to the impact power compensation topology structure, including: Calculating the active power and reactive power of the impulse power compensation topology structure according to the instantaneous power calculation theory; Determine a first transfer function of direct power outer loop control according to the active power and the reactive power; Determine a second transfer function of the power and current dual closed-loop control according to the first transfer function and the transfer function of the first-order low-pass filter; Power outer loop compensation control is performed according to the second transfer function.

8. A fusion power source impulse power compensation device, characterized in that: The device comprises: A characteristic analysis module is used to analyze the fusion power characteristics of the fusion power source and determine the power characteristics; A topology module, used for determining, according to the power characteristics, an impulse power compensation topology structure consisting of a DC filter inductor and a cascaded H-bridge topology including a lithium-ion capacitor in series; An inductance analysis module, used to determine the parameter value of the DC filter inductance in the impulse power compensation topology; A phase-locked loop control module, used for performing discrete dual-synchronous coordinate phase-locked loop control according to the impulse power compensation topology; A decoupling control module, used for performing current inner loop decoupling control according to the impact power compensation topology structure; A compensation control module, used for performing power outer loop compensation control according to the impulse power compensation topology structure and performing oscillation detection on the fusion power supply; The compensation module is used for synchronously compensating the impact active power and the impact reactive power by using the controlled impact power compensation topology when the fusion power source does not have oscillation.

9. A terminal device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for compensating the impact power of a fusion power source as claimed in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the method for compensating the impact power of a fusion power source as described in any one of claims 1 to 7.

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