Multi-wave-energy and electric-energy conversion device and active phase-shifting conversion method

Abstract

The invention relates to the technical field of energy conversion, and discloses a multi-wave-energy electric energy conversion device and an active phase-shifting conversion method.When an electric energy conversion request is received, a first electric energy conversion system and a second electric energy conversion system conduct electric energy conversion at the same time, and then a double-winding transformer is used for conducting voltage conversion on alternating-current electric energy; a high-order harmonic current channel is provided, and high-order harmonic current can form circulating current in the triangular winding, so that the transmission of harmonic waves is inhibited, and the quality of converted electric energy is further improved; adjusting and controlling by using the first operation data and the second operation data until the modulation phase difference between the modulation phase of the adjusted and controlled first generator and the modulation phase of the adjusted and controlled second generator is in a preset standard phase difference interval, and harmonic waves generated by the two generators can offset a part of each other; therefore, the total harmonic content of the system is reduced, and the electric energy quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conversion, and in particular to a multi-wave energy electric energy conversion device and an active phase shift conversion method. Background Art

[0002] As a key type of renewable energy, new energy has the characteristics of abundant resources, wide distribution and high energy flow density. Taking wave energy power generation devices as an example, they need to operate stably for a long time in harsh marine environments. In the utilization of wave energy, conversion efficiency and cost are the key factors restricting its large-scale application. Therefore, lightweight, easy-to-control and highly integrated multi-wave energy conversion devices have become an important development trend.

[0003] At present, rectifiers are typical equipment for adapting to the changes in electric energy of medium and high power synchronous generators. Under the action of the energy distribution unit and the gearbox, the synchronous generator generates electric energy, which is transformed and regulated by the rectifier to realize the control of power / energy transmission and the conversion of AC power into DC power, and is collected into the DC bus. Usually, synchronous generator sets operate independently and only interact at the energy management level. However, in the underlying operation control, they are shown as independent operation controls. Therefore, when a single rectifier drives the synchronous generator independently, the randomness of the rotation characteristics of the synchronous generator causes the DC ports of the rectifier to disturb each other, that is, there are a large number of harmonics in the DC voltage and AC current, which leads to a decrease in the quality of the converted power. Summary of the invention

[0004] The present invention provides a multi-wave energy electric energy conversion device and an active phase shift conversion method, which solves the technical problem of how to improve the quality of converted electric energy of renewable energy power generation.

[0005] A first aspect of the present invention provides a multi-wave energy power conversion device, comprising a first power conversion system and a second power conversion system;

[0006] The first power conversion system is connected to the second power conversion system via a double-winding transformer;

[0007] The first electric energy conversion system is used to perform electric energy conversion, and use the first current component after the electric energy conversion to perform closed-loop control of the motor, collect and generate and regulate the first generator based on the first operating data;

[0008] The second electric energy conversion system is used to perform electric energy conversion, and use the second current component after the electric energy conversion to perform closed-loop control of the motor, collect and generate and regulate the second generator based on the second operating data;

[0009] A modulation phase difference between the modulation phase of the first generator after adjustment and the modulation phase of the second generator after adjustment is within a preset standard phase difference range.

[0010] Optionally, the double-winding transformer is a DD-type double-winding transformer;

[0011] The double-winding transformer is used to perform voltage conversion on AC electric energy and provide a high-order harmonic current channel.

[0012] Optionally, the first power conversion system includes the first generator, a first rectifier and a first main control module;

[0013] The first generator is connected to the first rectifier via the primary winding of the double-winding transformer;

[0014] The first generator is used to convert mechanical energy into AC electrical energy;

[0015] The first rectifier is used to rectify the AC power to generate DC power;

[0016] The first generator and the first rectifier are both communicatively connected to the first main control module;

[0017] The first main control module is used to use the rectified current component after the rectification operation to perform closed-loop control of the motor, and to regulate the first generator according to the generated first operating data.

[0018] Optionally, the first main control module includes a first rotation speed submodule and a first position angle submodule;

[0019] The first operation data includes first rotation speed data and first position angle data;

[0020] The first speed submodule generates the first speed data for regulating the speed of the first generator motor according to the first current component;

[0021] The first position angle submodule is used to generate the first position angle data for regulating the position of the rotor of the first generator.

[0022] Optionally, the first speed submodule includes a first frequency locking unit, a first speed calculation unit, a first speed outer loop unit, a first current calculation unit, a first current inner loop unit, a first processing unit and a second processing unit which are communicatively connected in sequence;

[0023] The first frequency locking unit is used to obtain the first current zero-crossing period time difference and perform an inverse operation to obtain a first frequency locking speed component;

[0024] The first speed calculation unit is used to perform a difference calculation using the first preset reference speed component and the first frequency-locked speed component to obtain a first error speed;

[0025] The first speed outer loop unit is used to perform feedback control operation on the first error speed to generate a first reference current component;

[0026] The first current operation unit is used to perform a difference operation on the first reference current component and the first current component to obtain a first error current;

[0027] The first current inner loop unit is used to perform feedback control operation on the first error current to generate a first duty cycle parameter;

[0028] The first processing unit is used to perform a multiplication operation by using the first duty cycle parameter and a preset first transfer function to obtain first current data;

[0029] The second processing unit is used for performing a multiplication operation on the first current data and a preset second transfer function to generate the first rotation speed data.

[0030] Optionally, the first position angle submodule includes a first position angle calculation unit;

[0031] The first position angle calculation unit is used to perform an integration operation on the first frequency-locking rotation speed component to generate first position angle data.

[0032] Optionally, the second power conversion system includes the second generator, a second rectifier and a second main control module;

[0033] The second generator is connected to the second rectifier via the secondary winding of the double-winding transformer;

[0034] The second generator is used to convert mechanical energy into AC electrical energy;

[0035] The second rectifier is used to rectify the AC power to generate DC power;

[0036] The second generator and the second rectifier are both communicatively connected to the second main control module;

[0037] The second main control module is used to use the rectified current component after the rectification operation to perform closed-loop control of the motor, and to regulate the second generator according to the generated second operating data.

[0038] Optionally, the second main control module includes a second speed submodule and a second position angle submodule;

[0039] The second operation data includes second rotation speed data and second position angle data;

[0040] The second speed submodule generates the second speed data for regulating the speed of the second generator motor according to the second current component;

[0041] The second position angle submodule is used to generate the second position angle data for regulating the rotor position of the second generator.

[0042] Optionally, the second speed submodule includes a second frequency locking unit, a second speed calculation unit, a second speed outer loop unit, a second current calculation unit, a second current inner loop unit, a third processing unit and a fourth processing unit which are communicatively connected in sequence;

[0043] The second frequency locking unit is used to obtain the second current zero-crossing period time difference and perform an inverse operation to obtain a second frequency locking speed component;

[0044] The second speed calculation unit is used to perform a difference calculation using the second preset reference speed component and the second frequency-locked speed component to obtain a second error speed;

[0045] The second speed outer loop unit is used for performing feedback control operation on the second error speed to generate a second reference current component;

[0046] The second current operation unit is used to perform a difference operation on the second reference current component and the second current component to obtain a second error current;

[0047] The second current inner loop unit is used for performing feedback control operation on the second error current to generate a second duty cycle parameter;

[0048] The third processing unit is used for performing a multiplication operation by using the second duty cycle parameter and a preset third transfer function to obtain second current data;

[0049] The fourth processing unit is used for performing a multiplication operation on the second current data and a preset fourth transfer function to generate the second rotation speed data.

[0050] Optionally, the second position angle submodule comprises a phase locking unit, a synchronization unit and a delay unit which are communicatively connected in sequence;

[0051] The phase-locking unit is used to perform an integration operation on the second frequency-locking speed component to generate initial position angle data;

[0052] The synchronization unit is used to adjust the initial position angle data to be synchronized with the first position angle data to obtain intermediate position angle data;

[0053] The delay unit is used to perform a delay operation on the intermediate position angle data to generate the second position angle data.

[0054] The second aspect of the present invention provides an active phase shift conversion method applied to the multi-wave energy power conversion device, comprising:

[0055] Performing motor closed-loop control on the first current component after receiving the electric energy conversion to generate first operation data;

[0056] Performing motor closed-loop control on the second current component after receiving the electric energy conversion to generate second operation data;

[0057] The first operating data is used to regulate the first generator, and the second operating data is used to regulate the second generator, until a modulation phase difference between a modulation phase of the regulated first generator and a modulation phase of the regulated second generator is within a preset standard phase difference range.

[0058] It can be seen from the above technical solutions that the present invention has the following advantages:

[0059] In response to receiving an electric energy conversion request, the first electric energy conversion system and the second electric energy conversion system simultaneously perform electric energy conversion, and then use a dual-winding transformer to perform voltage conversion on the AC electric energy and provide a high-order harmonic current channel. The high-order harmonic current can form a circulating current inside the triangle winding, thereby suppressing the transmission of harmonics and further improving the quality of the converted electric energy; then the first current component and the second current component after the electric energy conversion are used to perform closed-loop control of the motor respectively to obtain first operating data and second operating data, and finally the first operating data is used to regulate the first generator, and the second operating data is used to regulate the second generator, until the modulation phase difference between the modulation phase of the regulated first generator and the modulation phase of the regulated second generator is in a preset standard phase difference range, and the harmonics generated by the two generators will offset each other partially, thereby reducing the total harmonic content of the system, thereby improving the quality of electric energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0061] Figure 1 It is a structural schematic diagram of a multi-wave energy electric energy conversion device according to an embodiment of the present invention;

[0062] Figure 2 is a schematic structural diagram of a first speed submodule according to an embodiment of the present invention;

[0063] Figure 3 is a schematic structural diagram of a second speed submodule according to an embodiment of the present invention;

[0064] Figure 4is a schematic structural diagram of a second position angle submodule according to an embodiment of the present invention;

[0065] Figure 5 A schematic diagram of voltage and current waveforms according to an embodiment of the present invention;

[0066] Figure 6 is a comparison diagram of the total harmonic distortion THD of the generator current and the diode side current in an embodiment of the present invention;

[0067] Figure 7 A flowchart of the steps of an active phase shift conversion method applied to a multi-wave energy power conversion device according to an embodiment of the present invention; DETAILED DESCRIPTION

[0068] The embodiments of the present invention provide a multi-wave energy power conversion device and an active phase shift conversion method, which are used to solve the technical problem of how to improve the quality of converted power generated by renewable energy.

[0069] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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.

[0070] The present invention is applied to the field of new energy power generation technology. In wave energy power generation technology, wave energy is a clean energy with the characteristics of stability and strong predictability, and has a wide range of application prospects. Large-scale wave energy power generation systems usually use multiple permanent magnet synchronous generators to achieve power conversion, collection and transmission through rectification and inversion links.

[0071] At present, Boost-PFC rectifiers are typical equipment for adapting to the changes in electric energy of medium and high power wave energy synchronous generators. Under the action of the energy distribution unit and the gearbox, the wave energy synchronous generator generates electric energy, which is transformed and regulated by the Boost-PFC rectifier to realize the control of power / energy transmission and the conversion of AC power into DC power, and is collected into the DC bus. Usually, Boost-PFC wave energy permanent magnet synchronous generator sets operate independently and only interact at the energy management level. However, in the underlying operation control, they are shown as independent operation control. Therefore, the randomness of the rotation characteristics of the wave energy permanent magnet synchronous generator causes the DC ports of the Boost-PFC rectifier to affect each other, that is, there are a large number of harmonics in the DC voltage and AC current.

[0072] In summary, when the existing single boost PFC rectifier independently drives the wave energy permanent magnet synchronous machine, the rectifier ports disturb each other, which leads to the degradation of the power quality converted by the system;

[0073] Each existing wave energy permanent magnet synchronous generator set requires two sets of Boost PFC rectifiers to meet the phase-shifting operation, which brings about the problem of high cost.

[0074] The present invention connects a double-winding transformer to enable two wave energy permanent magnet synchronous generators to have an AC voltage with a 60° phase shift characteristic, thereby increasing the DC voltage. However, for multiple wave energy permanent magnet synchronous generator sets, the existing transformer structure will lead to an increase in volume and weight. This is contrary to the lightweight topology. Therefore, the present invention proposes a simple power quality control and improvement scheme in the operation control framework of the boost-PFC type permanent magnet synchronous generator.

[0075] See also Figure 1-Figure 4 , a multi-wave energy power conversion device provided by the present invention comprises a first power conversion system and a second power conversion system;

[0076] The first power conversion system is connected to the second power conversion system via a double-winding transformer;

[0077] The first electric energy conversion system is used to perform electric energy conversion, and use the first current component after the electric energy conversion to perform motor closed-loop control, collect and generate and regulate the first generator based on the first operating data;

[0078] The second electric energy conversion system is used to perform electric energy conversion, and use the second current component after the electric energy conversion to perform closed-loop control of the motor, collect and generate and regulate the second generator based on the second operating data;

[0079] The modulation phase difference between the modulation phase of the first generator after regulation and the modulation phase of the second generator after regulation is within a preset standard phase difference range.

[0080] It should be noted that power conversion refers to the process of converting AC power generated by wave energy into DC power. Motor closed-loop control refers to closed-loop control of the first current component by connecting the Boost-PFC main circuit of the rectifier, thereby obtaining motor operation data for controlling the motor speed and rotor position of the generator. The first generator and the second generator both refer to permanent magnet synchronous generators. The first current component refers to the first current periodic component, and the second current component refers to the second current periodic component.

[0081] Figure 1This is a structural schematic diagram of a multi-wave energy conversion device. The two M's on the left side of the figure refer to two synchronous generators, PMSG1 and PMSG2 respectively. The two synchronous generators are connected through a gearbox shaft. A controller is provided in the gearbox that is communicated with the main control module to receive and regulate the two synchronous generators according to operating data. The right sides of the two synchronous generators are respectively connected to the primary winding side triangle (D) connection and the secondary winding side triangle (D) connection of a DD-type double-winding transformer. The AC sides of the two rectifiers are also respectively connected to the primary winding side triangle (D) connection and the secondary winding side triangle (D) connection of a DD-type double-winding transformer. Under this connection mode, when high-order harmonic current is generated on the primary side of the transformer, due to the characteristics of the triangle connection, the third harmonic current can circulate in the triangle winding. Similarly, in the triangle winding on the secondary side. When high-order harmonic currents are generated on the secondary side, these high-order harmonic currents can also circulate in the triangle winding on the secondary side, and due to the electromagnetic coupling relationship of the transformer, the high-order harmonic currents on the primary side and the secondary side will affect each other, and the high-order harmonic currents can circulate in the windings on both sides of the DD-type double-winding transformer, thereby providing a current channel for the high-order harmonics. The main circuits on the DC sides of the two rectifiers are both connected to the DC bus, and the circuit structures of the two rectifier main circuits are the same. The rectifier main circuits include a current transformer or a Hall current sensor, an inductor, a diode, a capacitor and an IGBT element; a current transformer or a Hall current sensor is arranged between the rectifier main circuit and the DC bus, and the current transformer or the Hall current sensor is connected in series with an inductor, and the end of the inductor away from the current transformer or the Hall current sensor is respectively connected to an IGBT element and a diode, and the end of the diode away from the inductor is connected to a capacitor, and the end of the capacitor away from the diode is connected to the DC bus.

[0082] It should be noted that the current transformer or the Hall current sensor is used to detect the first current component and the second current component after rectification, and the current component specifically refers to the current periodic component.

[0083] See also Figure 2-Figure 3 , Figure 2 is a schematic diagram of the structure of the first speed submodule, which includes a first frequency locking unit, a first speed calculation unit, a first speed outer loop unit, a first current calculation unit, a first current inner loop unit, a first processing unit and a second processing unit, which are sequentially connected in communication. i1 and plant i2 refer to the first processing subunit and the second processing subunit respectively;

[0084] Figure 3is a schematic diagram of the structure of the second speed submodule, which includes a second frequency locking unit, a second speed calculation unit, a second speed outer loop unit, a second current calculation unit, a second current inner loop unit, a third processing unit and a fourth processing unit, which are sequentially connected in communication. i3 and plant i4 They are referred to as the third processing sub-unit and the fourth processing sub-unit respectively.

[0085] See also Figure 4 , Figure 4 : is a schematic diagram of the structure of the second position angle submodule, the second position angle submodule comprises a phase locking unit, a synchronization unit and a delay unit which are communicatively connected in sequence.

[0086] In an embodiment of the present invention, in response to receiving an electric energy conversion request, the first electric energy conversion system and the second electric energy conversion system simultaneously perform electric energy conversion, and then use a double-winding transformer to perform voltage conversion on the AC electric energy and provide a high-order harmonic current channel. The high-order harmonic current can form a loop inside the triangle winding, thereby suppressing the transmission of harmonics and further improving the quality of the converted electric energy; then the first current component and the second current component after the electric energy conversion are used to respectively perform motor closed-loop control to obtain the first operation data and the second operation data, and finally the first operation data is used to regulate the first generator, and the second operation data is used to regulate the second generator, until the modulation phase difference between the modulation phase of the regulated first generator and the modulation phase of the regulated second generator is in a preset standard phase difference interval, that is, the modulation phase of the second generator is always maintained at a phase difference with the modulation phase between the first generator, and the harmonics generated by the two generators will offset each other partially. For example, the first generator may generate harmonics of certain specific frequencies. Due to the lag of the modulation phase, the phase relationship of the same-frequency harmonics generated by the second generator changes when superimposed. According to the principle of harmonic superposition, the superposition result of the same-frequency harmonics is related to their phase difference. Under this phase difference, some harmonics will weaken each other, thereby reducing the total harmonic content of the system and improving the power quality.

[0087] It is worth mentioning that the specific upper and lower limits of the preset standard phase difference interval can be determined according to engineering requirements. In the present invention, the preset standard phase difference interval is preferably The optimal modulation phase difference is preferably 60°, that is, the modulation phase of the second generator lags behind the modulation phase of the first generator by 60°. According to the test results, if the electromagnetic torque fluctuations of the two generators are not synchronized, it may cause fluctuations in the motor speed, thereby affecting the stability of the power generation frequency and voltage. By setting a 60° phase difference, the changes of the electromagnetic torque of the two within a cycle can be more coordinated, reducing power quality problems caused by electromagnetic torque fluctuations, such as frequency fluctuations and voltage flicker.

[0088] It should be noted that the modulation phase difference specifically refers to the electrical angle difference between the positions of the rotors of the two generators.

[0089] See also Figure 1 , the present invention provides a multi-wave energy power conversion device, the double-winding transformer is a DD type double-winding transformer;

[0090] The double-winding transformer is used to convert the voltage of AC power and provide a high-order harmonic current channel.

[0091] It should be noted that the right sides of the two synchronous generators are connected to the primary winding side triangle (D) connection and the secondary winding side triangle (D) connection of the DD-type double-winding transformer, and the AC sides of the two rectifiers are also connected to the primary winding side triangle (D) connection and the secondary winding side triangle (D) connection of the DD-type double-winding transformer. In this connection mode, when high-order harmonic currents are generated on the primary side of the transformer, due to the characteristics of the triangle connection, the third harmonic current can circulate in the triangle winding. Similarly, in the triangle winding on the secondary side. When high-order harmonic currents are generated on the secondary side, these high-order harmonic currents can also circulate in the triangle winding on the secondary side. Moreover, due to the electromagnetic coupling relationship of the transformer, the high-order harmonic currents on the primary and secondary sides will affect each other. The high-order harmonic currents can circulate in the windings on both sides of the DD-type double-winding transformer, thereby providing a current channel for high-order harmonics.

[0092] See also Figure 1 and Figure 2 , the present invention provides a multi-wave energy power conversion device, the first power conversion system includes a first generator, a first rectifier and a first main control module;

[0093] The first generator is connected to the first rectifier via the primary winding of the double-winding transformer;

[0094] The first generator is used to convert mechanical energy into AC electrical energy;

[0095] The first rectifier is used to rectify the AC power to generate DC power;

[0096] The first generator and the first rectifier are both communicatively connected to the first main control module;

[0097] The first main control module is used to perform closed-loop control of the motor using the rectified current component after the rectification operation, and to regulate the first generator according to the generated first operating data.

[0098] It should be noted that mechanical energy is converted into AC power through the first generator, the AC power is rectified by the first rectifier to generate DC power, the rectified current component after the rectification operation is used by the first main control module to perform closed-loop control of the motor, and the first generator is regulated according to the generated first operating data.

[0099] The first electric energy conversion system includes a first mechanical system and a first electrical system. The first mechanical system includes a gearbox, which is used to provide torque to the synchronous generator. Taking wave energy power generation as an example, in an actual wave energy power generation device, wave energy is collected by a collector, stored in a hydraulic accumulator, and further provided to the wave energy permanent magnet synchronous motor through an energy distribution unit and a gearbox shaft. In the present application, a gearbox of a synchronous generator is newly added to drive the speed and rotor position angle of the first generator according to the first operating data. In the present application, the first electrical system specifically includes a first generator, a first rectifier and its associated first main control module, and a DC bus.

[0100] The first main control module refers to a control main loop connected to the first rectifier main circuit, specifically refers to a Boost-PFC circuit connected to the DC side of the first rectifier for driving the first generator.

[0101] See also Figure 1 and Figure 2 , a multi-wave energy to electric energy conversion device provided by the present invention, the first main control module includes a first speed submodule and a first position angle submodule;

[0102] The first operation data includes first rotation speed data and first position angle data;

[0103] A first speed submodule, generating first speed data for regulating the speed of the first generator motor according to the first current component;

[0104] The first position angle submodule is used to generate first position angle data for controlling the position of the rotor of the first generator.

[0105] It should be noted that the speed data describes the rotation speed of the synchronous generator rotor, and the first speed data refers to data used to adjust the rotation speed of the synchronous generator rotor. The position angle data describes the angle of the position of the rotor relative to the stator, and the first position angle data refers to data used to adjust the angle of the position of the synchronous generator rotor relative to the stator.

[0106] The first position angle submodule includes a first position angle calculation unit;

[0107] The first position angle calculation unit is used to perform an integration operation on the first frequency-locking rotation speed component to generate first position angle data.

[0108] It is worth mentioning that since the phase is the integral of the frequency, the first position angle submodule is used to perform an integral operation on the first frequency-locked speed component to generate the first position angle data. , .

[0109] See also Figure 1 and Figure 2 , a multi-wave energy power conversion device provided by the present invention, the first speed submodule includes a first frequency locking unit, a first speed calculation unit, a first speed outer loop unit, a first current calculation unit, a first current inner loop unit, a first processing unit and a second processing unit which are sequentially communicatively connected;

[0110] The first frequency locking unit is used to obtain the first current zero-crossing period time difference and perform an inverse operation to obtain a first frequency locking speed component;

[0111] In an embodiment of the present invention, the main circuit on the DC side of the first rectifier is a Boost circuit, which drives the first generator. Since the first current periodic component appears after rectification, which is exactly twice the rotational speed, the frequency, that is, the first frequency-locked rotational speed component, can be obtained by detecting the time difference between the zero-crossing points of the current periodic component and taking the inverse. Therefore, the first frequency-locked unit is used to obtain the first current zero-crossing period time difference and perform an inverse operation to obtain the first frequency-locked rotational speed component.

[0112] It is worth mentioning that the first current zero-crossing period time difference refers to the time difference between the zero-crossing points of the first current periodic component.

[0113] The first speed calculation unit is used to perform a difference calculation using a first preset reference speed component and a first frequency-locking speed component to obtain a first error speed;

[0114] In the embodiment of the present invention, the first preset reference speed component is used The first frequency-locking speed component Perform a difference operation to obtain a first error speed.

[0115] The first speed outer loop unit is used for performing feedback control operation on the first error speed to generate a first reference current component;

[0116] In the embodiment of the present invention, the first error speed is input into the first speed outer loop for feedback control operation, that is, the first error speed is input into the speed regulator (PI or PID regulator), and processed by proportional-integral (PI) or proportional-integral-derivative (PID) control algorithm, and then the torque is calculated, so as to obtain the first reference current component .

[0117] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, wherein the first reference current component The calculation method can be as follows:

[0118]

[0119] In the formula, represents the first speed outer loop transfer function.

[0120] The first current operation unit is used to perform a difference operation using the first reference current component and the first current component to obtain a first error current;

[0121] In the embodiment of the present invention, the first reference current component is used and the first current component A difference operation is performed to obtain a first error current.

[0122] The first current inner loop unit is used to perform feedback control operation on the first error current to generate a first duty cycle parameter;

[0123] In an embodiment of the present invention, a first error current is input into a first current inner loop for feedback control operation, that is, the first error current is input into a current regulator (PI or PID regulator), processed by a proportional-integral (PI) or proportional-integral-derivative (PID) control algorithm, and then a duty cycle calculation is performed to obtain a first duty cycle parameter.

[0124] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, where the first duty cycle parameter The calculation method can be as follows:

[0125]

[0126] In the formula, represents the first current inner loop transfer function.

[0127] The first processing unit is used to perform a multiplication operation by using a first duty cycle parameter and a preset first transfer function to obtain first current data;

[0128] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, wherein the first current data The calculation method can be as follows:

[0129]

[0130] In the formula, It represents a preset first transfer function, specifically refers to a transfer function from a first duty cycle to a first inductor current.

[0131] It is worth mentioning that the first current data refers to the first inductor current.

[0132] The second processing unit is used for performing a multiplication operation on the first current data and a preset second transfer function to generate first rotation speed data.

[0133] In the specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula package, where the motor speed data The calculation method can be as follows:

[0134]

[0135] In the formula, It represents a preset second transfer function, specifically refers to a transfer function from the second inductor current to the second motor speed.

[0136] It should be noted that the first main control module also includes a first modulation link submodule, which is used to perform a modulation operation on the first operating data to generate a switch drive signal for controlling the first rectifier to start or stop power conversion.

[0137] Figure 1 The M in the first rectifier main circuit refers to the first modulation link sub-module, specifically the modulation link, which is used to determine whether the first generator operated according to the first operating data is in a preset standard operating data interval. If it is, a switch drive signal for turning on the IGBT is generated to maintain the current motor state. If it is not, it indicates that a deviation has occurred, and a switch drive signal for turning off the IGBT is generated.

[0138] See also Figure 1 , Figure 3 and Figure 4 , a multi-wave energy power conversion device provided by the present invention, the second power conversion system includes a second generator, a second rectifier and a second main control module;

[0139] The second generator is connected to the second rectifier via the secondary winding of the double-winding transformer;

[0140] The second generator is used to convert the mechanical energy into AC electrical energy;

[0141] The second rectifier is used to rectify the AC power to generate DC power;

[0142] The second generator and the second rectifier are both communicatively connected to the second main control module;

[0143] The second main control module is used to use the rectified current component after the rectification operation to perform closed-loop control of the motor, and to regulate the second generator according to the generated second operating data.

[0144] It should be noted that the mechanical energy is converted into AC power by the second generator, the AC power is rectified by the second rectifier to generate DC power, the rectified current component after the rectification operation is used by the second main control module to perform closed-loop control of the motor, and the second generator is regulated according to the generated second operating data.

[0145] The second electric energy conversion system includes a second mechanical system and a second electrical system. The second mechanical system includes a gearbox, which is used to provide torque to the synchronous generator. Taking wave energy power generation as an example, in an actual wave energy power generation device, wave energy is collected by a collector, stored in a hydraulic accumulator, and further provided to the wave energy permanent magnet synchronous motor through an energy distribution unit and a gearbox shaft. In the present application, a gearbox of a synchronous generator is newly added to drive the speed and rotor position angle of the second generator according to the second operating data. In the present application, the second electrical system specifically includes a second generator, a second rectifier and its associated second main control module, and a DC bus.

[0146] The second main control module refers to a control main loop connected to the second rectifier main circuit, specifically refers to a Boost-PFC circuit connected to the DC side of the second rectifier for driving the second generator.

[0147] See also Figure 1 , Figure 3 and Figure 4 , a multi-wave energy to electric energy conversion device provided by the present invention, the second main control module includes a second speed submodule and a second position angle submodule;

[0148] The second operation data includes second rotation speed data and second position angle data;

[0149] A second speed submodule, generating second speed data for regulating the speed of the second generator motor according to the second current component;

[0150] The second position angle submodule is used to generate second position angle data for regulating the rotor position of the second generator.

[0151] It should be noted that the speed data describes the rotation speed of the synchronous generator rotor, and the second speed data refers to data used to adjust the rotation speed of the synchronous generator rotor. The position angle data describes the angle of the position of the rotor relative to the stator, and the second position angle data refers to data used to adjust the angle of the position of the synchronous generator rotor relative to the stator.

[0152] See also Figure 1 , Figure 3 and Figure 4 , a multi-wave energy power conversion device provided by the present invention, the second speed submodule includes a second frequency locking unit, a second speed calculation unit, a second speed outer loop unit, a second current calculation unit, a second current inner loop unit, a third processing unit and a fourth processing unit which are sequentially communicatively connected;

[0153] The second frequency locking unit is used to obtain the second current zero-crossing period time difference and perform an inverse operation to obtain a second frequency locking speed component;

[0154] In an embodiment of the present invention, the main circuit on the DC side of the second rectifier is a Boost circuit, which drives the second generator. Since a second current periodic component appears after rectification, which is exactly twice the rotational speed, the frequency, that is, the second frequency-locked rotational speed component, can be obtained by detecting the time difference between the zero-crossing points of the current periodic component and taking the inverse. Therefore, the second frequency-locked rotational speed component is obtained by using the second frequency-locked unit to obtain the second current zero-crossing period time difference and perform an inverse operation to obtain the second frequency-locked rotational speed component.

[0155] It is worth mentioning that the second current zero-crossing period time difference refers to the time difference between the zero-crossing points of the second current periodic component.

[0156] The second speed calculation unit is used to perform a difference calculation using a second preset reference speed component and a second frequency-locked speed component to obtain a second error speed;

[0157] In the embodiment of the present invention, the second preset reference speed component is used The second frequency-locking speed component Perform a difference operation to obtain a second error speed.

[0158] The second speed outer loop unit is used for performing feedback control operation on the second error speed to generate a second reference current component;

[0159] In the embodiment of the present invention, the second error speed is input into the second speed outer loop for feedback control operation, that is, the second error speed is input into the speed regulator (PI or PID regulator), and processed by proportional-integral (PI) or proportional-integral-derivative (PID) control algorithm, and then the torque is calculated, so as to obtain the second reference current component .

[0160] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, wherein the second reference current component The calculation method can be as follows:

[0161]

[0162] In the formula, represents the second speed outer loop transfer function.

[0163] The second current operation unit is used to perform a difference operation using the second reference current component and the second current component to obtain a second error current;

[0164] In the embodiment of the present invention, the second reference current component is used and the second current component A difference operation is performed to obtain a second error current.

[0165] The second current inner loop unit is used for performing feedback control operation on the second error current to generate a second duty cycle parameter;

[0166] In an embodiment of the present invention, a second error current is input into a second current inner loop for feedback control operation, that is, the second error current is input into a current regulator (PI or PID regulator), processed using a proportional-integral (PI) or proportional-integral-derivative (PID) control algorithm, and then the duty cycle is calculated to obtain a second duty cycle parameter.

[0167] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, where the second duty cycle parameter The calculation method can be as follows:

[0168]

[0169] In the formula, represents the second current inner loop transfer function.

[0170] The third processing unit is used for performing a multiplication operation by using the second duty cycle parameter and a preset third transfer function to obtain second current data;

[0171] In a specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula encapsulation form, wherein the second current data The calculation method can be as follows:

[0172]

[0173] In the formula, It represents a preset third transfer function, specifically refers to a transfer function from the second duty cycle to the second inductor current.

[0174] The fourth processing unit is used for performing a multiplication operation on the second current data and a preset fourth transfer function to generate second rotation speed data.

[0175] In the specific implementation, in order to facilitate the implementation of the method, the above process can be converted into a formula package, where the motor speed data The calculation method can be as follows:

[0176]

[0177] In the formula, It represents a preset fourth transfer function, specifically refers to a transfer function from the second inductor current to the second motor speed.

[0178] See also Figure 4 , a multi-wave energy to electric energy conversion device provided by the present invention, the second position angle submodule comprises a phase locking unit, a synchronization unit and a delay unit which are sequentially communicatively connected;

[0179] The phase-locking unit is used to perform an integration operation on the second frequency-locking speed component to generate initial position angle data;

[0180] In the embodiment of the present invention, since the phase is the integral of the frequency, the phase locking unit is used to perform an integral operation on the second frequency-locked speed component to generate the initial position angle data. .

[0181] The synchronization unit is used to adjust the initial position angle data to be synchronized with the first position angle data to obtain the intermediate position angle data;

[0182] In the embodiment of the present invention, the first position angle data and initial position angle data Input synchronization unit for synchronization, that is, adjust the initial position angle data To the first position angle data equal, the intermediate position angle data output at this time is equal to the first position angle data .

[0183] The delay unit is used to perform a delay operation on the intermediate position angle data to generate second position angle data.

[0184] It should be noted that the intermediate position angle data is delayed, for example, to make the modulation phase difference between the modulation phase of the first generator after regulation and the modulation phase of the second generator after regulation be 60°, that is, to make the modulation phase of the second generator lag behind the modulation phase of the first generator by 60°, and calculate the rotor position angle of the second generator when the second generator is delayed by 1 / 6 cycle as the second position angle data .

[0185] For ease of understanding, a specific calculation example is provided below:

[0186] Determine the relevant parameters and basic relationships:

[0187] Assume that the modulation phase of the first generator is , the modulation phase of the second generator is , known ;

[0188] Assuming the period of the first generator is T, for the rotational motion of the first generator, the motor speed obtained by the above steps is (in degrees per second), and .

[0189] Calculate the rotor position angle of the second generator after a delay of 1 / 6T:

[0190] Assume that starting from the initial moment, the rotor position angle of the first generator within time t is .

[0191] The second generator is delayed by 1 / 6T, so the actual running time of the second generator is t .

[0192] So the rotor position angle of the second generator is .

[0193] because , substituting it into the above formula, we can get °, therefore, when the second generator is delayed by 1 / 6T, the second position angle data °.

[0194] It should be noted that the second main control module also includes a second modulation link submodule, which is used to modulate the second operating data to generate a switch drive signal for controlling the second rectifier to start or stop power conversion.

[0195] Figure 1 The M in the second rectifier main circuit refers to the second modulation link sub-module, specifically the modulation link, which is used to determine whether the second generator operated according to the second operating data is in a preset standard operating data interval. If it is, a switch drive signal for turning on the IGBT is generated to maintain the current motor state. If it is not, it indicates that a deviation has occurred, and a switch drive signal for turning off the IGBT is generated.

[0196] It should be noted that the rectifier is a diode uncontrolled rectifier, which has a simple structure, low cost, and can achieve high redundancy operation.

[0197] The following is an application example:

[0198] Compared with the conventional method of directly connecting the generator and the rectifier, the fifth harmonic elimination effect of the generator side current of the present invention is reduced from 1.18876 to 0.312046, and the corresponding seventh harmonic elimination effect is reduced from 0.2849 to 0.1264. Figure 5 , Figure 6As shown. It can be seen that the present invention greatly optimizes the current waveform on the generator side. The present invention sets the phase of the second generator to lag behind the phase of the first generator by 60°, and further crosses the transformer by D11d11, effectively reducing the harmonic component of the AC measurement, and solves the problem of excessive harmonics on the generator side current caused by uncontrolled rectification of diodes.

[0199] See also Figure 7 The present invention provides an active phase shift conversion method for a multi-wave energy power conversion device, comprising:

[0200] Step 101: Perform motor closed-loop control on the first current component received after electric energy conversion to generate first operating data.

[0201] Step 102: Perform motor closed-loop control on the second current component after receiving the electric energy conversion to generate second operation data.

[0202] Step 103: Use the first operating data to regulate the first generator, and use the second operating data to regulate the second generator, until the modulation phase difference between the modulation phase of the regulated first generator and the modulation phase of the regulated second generator is within a preset standard phase difference range.

[0203] In an embodiment of the present invention, in response to receiving an electric energy conversion request, the first electric energy conversion system and the second electric energy conversion system simultaneously perform electric energy conversion, and then use a double-winding transformer to perform voltage conversion on the AC electric energy and provide a high-order harmonic current channel. The high-order harmonic current can form a loop inside the triangle winding, thereby suppressing the transmission of harmonics and further improving the quality of the converted electric energy; then the first current component and the second current component after the electric energy conversion are used to respectively perform motor closed-loop control to obtain the first operation data and the second operation data, and finally the first operation data is used to regulate the first generator, and the second operation data is used to regulate the second generator, until the modulation phase difference between the modulation phase of the regulated first generator and the modulation phase of the regulated second generator is in a preset standard phase difference interval, that is, the modulation phase of the second generator is always maintained at a phase difference with the modulation phase between the first generator, and the harmonics generated by the two generators will offset each other partially. For example, the first generator may generate harmonics of certain specific frequencies. Due to the lag of the modulation phase, the phase relationship of the same-frequency harmonics generated by the second generator changes when superimposed. According to the principle of harmonic superposition, the superposition result of the same-frequency harmonics is related to their phase difference. Under this phase difference, some harmonics will weaken each other, thereby reducing the total harmonic content of the system and improving the power quality. The present invention improves the power quality through an active phase shift conversion method, that is, adjusting the modulation phase difference between the modulation phase of the first generator and the modulation phase of the regulated second generator.

[0204] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0205] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0206] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-wave energy power conversion device, characterized in that: including a first electric energy conversion system and a second electric energy conversion system; The first power conversion system is connected to the second power conversion system via a double-winding transformer; The first electric energy conversion system is used to perform electric energy conversion, and use the first current component after the electric energy conversion to perform closed-loop control of the motor, collect and generate and regulate the first generator based on the first operating data; The second electric energy conversion system is used to perform electric energy conversion, and use the second current component after the electric energy conversion to perform closed-loop control of the motor, collect and generate and regulate the second generator based on the second operating data; A modulation phase difference between the modulation phase of the first generator after adjustment and the modulation phase of the second generator after adjustment is within a preset standard phase difference range.

2. The multi-wave energy power conversion device according to claim 1 is characterized in that: The first electric energy conversion system includes the first generator, a first rectifier and a first main control module; The first generator is connected to the first rectifier via the primary winding of the double-winding transformer; The first generator is used to convert mechanical energy into AC electrical energy; The first rectifier is used to rectify the AC power to generate DC power; The first generator and the first rectifier are both communicatively connected to the first main control module; The first main control module is used to use the rectified current component after the rectification operation to perform closed-loop control of the motor, and to regulate the first generator according to the generated first operating data.

3. The multi-wave energy power conversion device according to claim 1 is characterized in that: The first main control module includes a first speed submodule and a first position angle submodule; The first operation data includes first rotation speed data and first position angle data; The first speed submodule generates the first speed data for regulating the speed of the first generator motor according to the first current component; The first position angle submodule is used to generate the first position angle data for regulating the position of the rotor of the first generator.

4. The multi-wave energy power conversion device according to claim 3 is characterized in that: The first speed submodule includes a first frequency locking unit, a first speed calculation unit, a first speed outer loop unit, a first current calculation unit, a first current inner loop unit, a first processing unit and a second processing unit which are communicatively connected in sequence; The first frequency locking unit is used to obtain the first current zero-crossing period time difference and perform an inverse operation to obtain a first frequency locking speed component; The first speed calculation unit is used to perform a difference calculation using the first preset reference speed component and the first frequency-locked speed component to obtain a first error speed; The first speed outer loop unit is used to perform feedback control operation on the first error speed to generate a first reference current component; The first current operation unit is used to perform a difference operation on the first reference current component and the first current component to obtain a first error current; The first current inner loop unit is used to perform feedback control operation on the first error current to generate a first duty cycle parameter; The first processing unit is used to perform a multiplication operation by using the first duty cycle parameter and a preset first transfer function to obtain first current data; The second processing unit is used for performing a multiplication operation on the first current data and a preset second transfer function to generate the first rotation speed data.

5. The multi-wave energy power conversion device according to claim 4 is characterized in that: The first position angle submodule comprises a first position angle calculation unit; The first position angle calculation unit is used to perform an integration operation on the first frequency-locking rotation speed component to generate first position angle data.

6. The multi-wave energy power conversion device according to any one of claims 1 to 5, characterized in that: The second electric energy conversion system includes the second generator, a second rectifier and a second main control module; The second generator is connected to the second rectifier via the secondary winding of the double-winding transformer; The second generator is used to convert mechanical energy into AC electrical energy; The second rectifier is used to rectify the AC power to generate DC power; The second generator and the second rectifier are both communicatively connected to the second main control module; The second main control module is used to use the rectified current component after the rectification operation to perform closed-loop control of the motor, and to regulate the second generator according to the generated second operating data.

7. The multi-wave energy power conversion device according to claim 6, characterized in that: The second main control module includes a second speed submodule and a second position angle submodule; The second operation data includes second rotation speed data and second position angle data; The second speed submodule generates the second speed data for regulating the speed of the second generator motor according to the second current component; The second position angle submodule is used to generate the second position angle data for regulating the rotor position of the second generator.

8. The multi-wave energy power conversion device according to claim 7, characterized in that: The second speed submodule includes a second frequency locking unit, a second speed calculation unit, a second speed outer loop unit, a second current calculation unit, a second current inner loop unit, a third processing unit and a fourth processing unit which are sequentially communicatively connected; The second frequency locking unit is used to obtain the second current zero-crossing period time difference and perform an inverse operation to obtain a second frequency locking speed component; The second speed calculation unit is used to perform a difference calculation using the second preset reference speed component and the second frequency-locked speed component to obtain a second error speed; The second speed outer loop unit is used for performing feedback control operation on the second error speed to generate a second reference current component; The second current operation unit is used to perform a difference operation on the second reference current component and the second current component to obtain a second error current; The second current inner loop unit is used for performing feedback control operation on the second error current to generate a second duty cycle parameter; The third processing unit is used for performing a multiplication operation by using the second duty cycle parameter and a preset third transfer function to obtain second current data; The fourth processing unit is used for performing a multiplication operation on the second current data and a preset fourth transfer function to generate the second rotation speed data.

9. The multi-wave energy power conversion device according to claim 8, characterized in that: The second position angle submodule comprises a phase locking unit, a synchronization unit and a delay unit which are communicatively connected in sequence; The phase-locking unit is used to perform an integration operation on the second frequency-locking speed component to generate initial position angle data; The synchronization unit is used to adjust the initial position angle data to be synchronized with the first position angle data to obtain intermediate position angle data; The delay unit is used to perform a delay operation on the intermediate position angle data to generate the second position angle data.

10. An active phase shift conversion method applied to the multi-wave energy power conversion device according to any one of claims 1 to 9, characterized in that: include: Performing motor closed-loop control on the first current component after receiving the electric energy conversion to generate first operation data; Performing motor closed-loop control on the second current component after receiving the electric energy conversion to generate second operation data; The first operating data is used to regulate the first generator, and the second operating data is used to regulate the second generator, until a modulation phase difference between a modulation phase of the regulated first generator and a modulation phase of the regulated second generator is within a preset standard phase difference range.

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