CN111817449A - Wireless power supply system for motor rotor - Google Patents
Wireless power supply system for motor rotor Download PDFInfo
- Publication number
- CN111817449A CN111817449A CN202010596368.4A CN202010596368A CN111817449A CN 111817449 A CN111817449 A CN 111817449A CN 202010596368 A CN202010596368 A CN 202010596368A CN 111817449 A CN111817449 A CN 111817449A
- Authority
- CN
- China
- Prior art keywords
- phase
- compensation
- winding
- secondary side
- rotor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/10—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling
- H02J50/12—Circuit arrangements or systems for wireless supply or distribution of electric power using inductive coupling of the resonant type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F38/00—Adaptations of transformers or inductances for specific applications or functions
- H01F38/18—Rotary transformers
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
- H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
- H02M5/22—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M5/275—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/293—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/16—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using ac to ac converters without intermediate conversion to dc
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Control Of Ac Motors In General (AREA)
- Ac-Ac Conversion (AREA)
Abstract
The invention discloses a wireless power supply system for a motor rotor, which comprises a main circuit system and a control system; the main circuit system comprises a three-phase full-bridge circuit, a single-phase full-bridge circuit, a magnetic coupling resonance network, an AC-AC frequency conversion circuit and a wound motor rotor. The magnetic coupling resonance network comprises a primary side compensation network, a rotary transformer and three secondary side compensation networks; the primary side compensation network is connected with a fixed winding in the rotary transformer to form single-phase input; the three secondary side compensation networks are respectively connected with a rotary winding in the rotary transformer to form three-phase output; the control system comprises a controller 1, a controller 2 and a wireless information transmission module; the controller 1 can control a three-phase full-bridge circuit and a single-phase full-bridge circuit; the controller 2 can control the three-phase AC/AC frequency conversion circuit. The invention can completely replace a motor rotor wireless power supply system of a slip ring device, and can realize the frequency conversion control of rotor electric energy and the bidirectional flow of energy.
Description
Technical Field
The invention relates to the field of motor control, power electronic transformers and wireless power transmission, in particular to a wireless power supply system for a motor rotor.
Background
With the rapid development of power electronic technologies such as power silicon carbide in recent decades, high-frequency power electronic transformers have attracted much attention in recent decades. Meanwhile, wireless power transmission is rapidly developed, non-contact power transmission is researched greatly, and efficiency is higher and higher.
Motor equipment is widely applied in daily production and life, however, the slip ring and the electric brush of the motor easily generate sparks and dust during operation, the safety and reliability of the operation of the motor are seriously influenced, meanwhile, the maintenance of the motor is very difficult under some special environments, and the application environment of the motor is limited by the slip ring and the electric brush.
Under the background, the invention combines the principles of electromagnetism, power electronics and wireless energy transmission to provide a motor power supply system for supplying power to an alternating current motor rotor, the system can replace a brush slip ring mechanism of a motor, the safety problem of the motor caused by poor contact of a brush is eliminated, the running stability of the motor is improved, and the physical maintenance of the motor is reduced.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a wireless power supply system for a motor rotor, which combines electromagnetic, power electronics and wireless energy transmission, completely replaces a wireless power supply system for a motor rotor of a slip ring device, and can realize variable frequency control of rotor electric energy and bidirectional flow of energy.
In order to solve the technical problems, the invention adopts the technical scheme that:
a wireless power supply system for a motor rotor comprises a main circuit system and a control system.
The main circuit system comprises a three-phase full-bridge circuit, a single-phase full-bridge circuit, a magnetic coupling resonance network, an AC-AC frequency conversion circuit and a wound motor rotor.
And a three-phase full-bridge circuit in the main circuit system is directly connected with a power grid. The three-phase full-bridge circuit is connected with the single-phase full-bridge circuit through a filter capacitor. The single-phase full-bridge circuit is connected with the magnetic coupling resonance network. The magnetic coupling resonance network comprises a primary side compensation network, a rotary transformer and three secondary side compensation networks. The primary side compensation network is connected with a fixed winding in the rotary transformer to form single-phase input. The three secondary side compensation networks are respectively connected with the rotary winding in the rotary transformer to form three-phase output.
The three-phase output is respectively connected with the three-phase AC-AC frequency conversion circuit. The three-phase AC-AC frequency conversion circuit is directly connected with a three-phase winding of a winding motor rotor.
The control system comprises a controller 1, a controller 2 and a wireless information transmission module.
The controller 1 is respectively connected with a power grid, a three-phase full-bridge circuit and a single-phase full-bridge circuit and can collect primary side electric quantity information. The primary side electric quantity information comprises a voltage current signal of a power grid and a direct current bus voltage.
The controller 2 is respectively connected with the three-phase AC/AC frequency conversion circuit and the winding motor rotor and can collect secondary side electric quantity information. And the secondary side electrical quantity information comprises voltage and current of a wound motor rotor, rotor rotating speed and rotor torque.
The controller 1 controls the three-phase full bridge circuit through the collected primary side electric quantity information, so that the voltage of the direct current bus is kept stable; on the other hand, the single-phase full bridge circuit is controlled by combining the secondary side electric quantity information fed back by the controller 2, so that the direct current is changed into high-frequency alternating current with different duty ratios, and the effect of controlling the transmission power is achieved;
the controller 2 controls the three-phase AC/AC frequency conversion circuit by collecting the secondary side electric quantity information and combining the primary side electric quantity information fed back by the controller 1, and provides low-frequency AC power for the winding motor rotor, so that the winding motor rotor can stably run.
The three-phase AC-AC frequency conversion circuit can be formed by a three-phase independent full-bridge circuit; each phase of full-bridge circuit consists of four bidirectional switches connected in an H-bridge structure; each bidirectional switch is composed of a three-phase AC/AC frequency conversion circuit formed by reversely connecting two switch tubes with anti-parallel diodes in series, a three-phase output of a magnetic coupling resonance network and a three-phase rotor winding of a winding motor rotor in series, and a secondary side of a main circuit system is formed.
Each crossed alternating frequency circuit in the three-phase alternating frequency conversion circuit can be composed of two H bridges which are connected in an anti-parallel mode, and each H bridge comprises four switching tubes. The three-phase alternating-current and alternating-current frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
The three-phase AC-AC frequency conversion circuit can be a three-phase matrix converter which is formed by arranging nine groups of bidirectional switches in a 3 multiplied by 3 matrix form. Each bidirectional switch comprises two switching tubes which are connected in series in an opposite direction and provided with anti-parallel diodes. The three-phase alternating-current and alternating-current frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
The primary side compensation network and the three secondary side compensation networks are all parallel compensation structures and respectively comprise a compensation capacitor and a compensation inductor. In the primary side compensation network, a compensation capacitor is connected in parallel at two ends of a primary side winding of a rotary transformer, and a compensation inductor is connected with the primary side winding of the rotary transformer in series and then connected with a unidirectional full bridge. In the three secondary side compensation networks, each compensation capacitor is connected in parallel at two ends of the secondary side winding of the rotary transformer, and the compensation inductor is connected with the secondary side winding of the rotary transformer in series and then connected with the AC-AC frequency conversion circuit of the corresponding phase.
The primary side compensation network and the three secondary side compensation networks respectively comprise a compensation capacitor and a compensation inductor which is connected with the compensation capacitor in series.
The primary side compensation network and the three secondary side compensation networks are all LCC compensation structures and respectively comprise a compensation inductor and two compensation capacitors. The two compensation capacitors are respectively a first compensation capacitor and a second compensation capacitor. In the primary side compensation network, a first compensation capacitor is connected in parallel at two ends of a primary side winding of a rotary transformer, and a compensation inductor, the primary side winding of the rotary transformer and a second compensation capacitor are sequentially connected in series and then connected with a unidirectional full bridge. In the three secondary side compensation networks, each first compensation capacitor is connected in parallel at two ends of the secondary side winding of the rotary transformer, and the compensation inductor, the secondary side winding of the rotary transformer and the second compensation capacitor are sequentially connected in series and then connected with the AC-AC frequency conversion circuit of the corresponding phase.
The switching elements in the three-phase full-bridge circuit, the single-phase full-bridge circuit and the three-phase AC-AC frequency conversion circuit are all power semiconductor switching devices, and the types of the power semiconductor switching devices are IGBT, MOSFET or SiC-MOSFET.
The controller 1 and the controller 2 each include an information sampling module, an information processing module, and a driving module. The information sampling module comprises a voltage and current sampling module and a rotating speed and torque detection module. The information processing module adopts a DSP control chip. The driving module changes the control signal into a switching tube driving signal.
The invention has the following beneficial effects:
1. the secondary side of the invention adopts the AC-AC frequency conversion circuit to replace the traditional AC-DC-AC frequency conversion circuit, so that the large filtering capacitor in the AC-DC-AC circuit can be omitted, the volume of the system is greatly reduced, and the system can be applied to occasions with requirements on the volume of equipment; the structure can realize the bidirectional flow of electric energy, can supply power to the motor rotor in practical application, and can also feed the rotor electric energy back to a power grid, so that the electric energy transmission control is flexible, the working requirement of the motor can be greatly met, and the electric energy utilization rate of the motor is improved; the rotary transformer in the magnetic coupling resonance network adopts a magnetic integration technology, one-phase input and three-phase output are realized, and the energy utilization rate is greatly improved; the three-phase independent AC-AC frequency conversion circuit can realize independent control of three-phase winding current of the motor rotor, and the fault-tolerant capability of a motor rotor control system is improved.
2. The compensation network in the invention can adopt a series compensation structure, a parallel compensation structure and an LCC compensation structure, and different compensation structures have different electrical properties and can be applied to various conditions. The series compensation network is a network with a wide application range at present, and the network is simple in structure, easy to control and good in gain characteristic. The parallel compensation structure has better stability than the series compensation structure, the current in the primary side coil of the parallel compensation structure can not change along with the mutual inductance change of the transformer, the primary side current is also kept unchanged under the condition that the secondary side is short-circuited, and the secondary side current returns to zero, so that the safety of the system can be better ensured. Compared with a parallel compensation network, the LCC compensation network has the advantages that a blocking capacitor is connected in series in a coil branch, the structure has the advantage of high stability of the parallel compensation topology, and meanwhile, the transmission power of the LCC compensation network is higher than that of the parallel compensation topology.
3. The AC-AC frequency conversion circuit has various structures, including a three-phase bridge structure consisting of bidirectional switches, a frequency conversion circuit consisting of H bridges in reverse parallel connection, and a matrix converter with flexible control. The three-phase full-bridge AC-AC frequency conversion circuit composed of the bidirectional switches is a commonly used AC-AC frequency conversion circuit, the circuit structure uses a large number of switch tubes, but the voltage resistance requirement on a single switch tube is reduced, and the three-phase full-bridge AC-AC frequency conversion circuit can be used in most application occasions. The switch tube used in the AC-AC frequency conversion circuit formed by the anti-parallel H bridge does not need an anti-parallel diode, thereby reducing the number of power elements. The circuit is usually made by cosine wave cross-cut control, has low power factor, is not suitable for high-frequency occasions, and is generally used in high-voltage low-frequency occasions. The matrix converter composed of bidirectional switches is a novel AC-AC frequency conversion circuit, which can convert electric energy of any voltage and frequency into electric energy of another voltage and frequency, and has the characteristics of good output current waveform, high input power factor and bidirectional power flow. The topological structure can be used in various occasions needing electric energy conversion.
Drawings
Fig. 1 shows a structure diagram of a wireless power supply system for a motor rotor according to the invention.
Fig. 2 shows a typical topology of the main circuit system of the present invention.
Fig. 3 shows a diagram of the application of different compensation networks in a wireless power supply system for a rotor of an electric machine. Wherein, fig. 3 (a) shows that the compensation network is a series compensation structure; fig. 3 (b) shows the compensation network as a LCC compensation structure.
Fig. 4 shows the application of different ac/ac frequency conversion circuits in the wireless power supply system of the motor rotor. Wherein, fig. 4 (a) shows that the ac-ac frequency conversion circuit is an anti-parallel H-bridge circuit; fig. 4 (b) shows the ac-to-ac converter circuit as a three-phase matrix converter.
Fig. 5 shows a sectional structure view of the resolver.
Among them are:
1. a stationary portion of the rotary transformer; 11. fixing the magnetic core; 12. fixing the winding; 13. fixing the groove;
2. a rotating portion of a rotary transformer; 21. rotating the magnetic core; 22. rotating the winding; 23. rotating the groove;
S1-S6 power electronic power switches in the three-phase full bridge circuit; S11-S14, power electronic power switches in the single-phase full-bridge circuit; S21-S224. power electronic power switches in the three-phase AC-AC frequency conversion circuit; C1. a filter capacitor; C11-C12, a resonant capacitor in the primary side compensation network; l11, a resonant inductor in the primary side compensation network; C21-C26, resonance capacitance in the secondary side compensation network; l21~ L23 resonance inductance in the secondary side compensation network.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific preferred embodiments.
In the description of the present invention, it is to be understood that the terms "left side", "right side", "upper part", "lower part", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and that "first", "second", etc., do not represent an important degree of the component parts, and thus are not to be construed as limiting the present invention. The specific dimensions used in the present example are only for illustrating the technical solution and do not limit the scope of protection of the present invention.
As shown in fig. 1 and fig. 2, a wireless power supply system for a rotor of an electric machine comprises a main circuit system and a control system.
The main circuit system comprises a three-phase full-bridge circuit, a single-phase full-bridge circuit, a magnetic coupling resonance network, an AC-AC frequency conversion circuit and a wound motor rotor.
And a three-phase full-bridge circuit in the main circuit system is directly connected with a power grid.
As shown in FIG. 2, the six power electronic power switches in the three-phase full-bridge circuit are S1-S6.
The three-phase full-bridge circuit is connected with the single-phase full-bridge circuit through a filter capacitor. The four power electronic power switches in the unidirectional full bridge are respectively S11-S14.
The single-phase full-bridge circuit is connected with the magnetic coupling resonance network.
The magnetic coupling resonance network comprises a primary side compensation network, a rotary transformer and three secondary side compensation networks. The primary side compensation network is connected with a fixed winding in the rotary transformer to form single-phase input. The three secondary side compensation networks are respectively connected with the rotary winding in the rotary transformer to form three-phase output. The three-phase output is respectively connected with the three-phase AC-AC frequency conversion circuit. The three-phase AC-AC frequency conversion circuit is directly connected with a three-phase winding of a winding motor rotor.
The resolver magnetic circuit includes a fixed portion and a rotating portion.
As shown in fig. 5, the fixed portion includes a fixed magnetic core 11 and a fixed winding 12. The stationary magnetic core is preferably mounted inside or outside the motor casing. The stationary winding 12 is also referred to as a primary winding.
The rotating part comprises a rotating core 21 and a rotating winding 22, the rotating winding 22 is also called secondary winding. The rotary transformer of the present invention has a three-phase secondary side winding.
The rotating magnetic core is arranged on a rotating shaft of the winding motor rotor and rotates along with the rotating shaft. The rotor of the winding motor is coaxially sleeved on the periphery of the rotating shaft, and a three-phase rotor winding is arranged in the rotor of the winding motor, is used for inputting electric energy or outputting electric energy and is a terminal of a rotor power supply system.
The rotating core and the fixed core are preferably made of anisotropic magnetic lamination material such as ferrite magnetic material or amorphous alloy.
The rotary magnetic core and the fixed magnetic core are preferably groove rings, and the opening directions of the grooves of the groove rings are opposite. The grooves of the rotary magnetic core are rotary grooves 23, and rotary winding teeth are formed between adjacent rotary grooves and used for winding rotary windings. The groove for fixing the magnetic core is a fixing groove 13, and a fixing winding tooth is formed between adjacent fixing grooves and used for winding a fixing winding.
A fixed magnetic circuit air gap is arranged between the fixed magnetic core and the rotary magnetic core; when the rotating shaft drives the rotating magnetic core to rotate, wireless alternating current transmission can be realized between the fixed part and the rotating part of the rotary transformer.
The primary side compensation network and the three secondary side compensation networks are collectively called compensation networks, and three specific embodiments are preferred.
Embodiment 1 compensation network is a parallel compensation structure
The primary side compensation network and the three secondary side compensation networks respectively comprise a compensation capacitor and a compensation inductor.
As shown in fig. 2, in the primary-side compensation network, a compensation capacitor L11 is connected in parallel to both ends of the primary winding of the resolver, and a compensation inductor L11 is connected in series with the primary winding of the resolver and then connected to the midpoints of both arms of the unidirectional full bridge.
In the three secondary side compensation networks, each compensation capacitor (C21, C22 or C23) is connected in parallel at two ends of the secondary side winding of the rotary transformer, and the compensation inductor (L21, L22 or L23) is connected in series with the secondary side winding of the rotary transformer and then connected with the AC-AC frequency conversion circuit of the corresponding phase.
In the parallel compensation structure, the compensation capacitor is connected in parallel with the primary winding, the compensation inductor is connected in series with the primary winding and the compensation capacitor, and the compensation inductor is generally the same as the inductance of the primary winding. The compensation structure has good stability, the current in the primary side winding of the compensation structure can not change along with the mutual inductance change of the transformer, the primary side current is also kept unchanged under the condition that the secondary side of the compensation structure is short-circuited, the secondary side current returns to zero, and the safety of the system can be better ensured. The resonance structure has certain suppression effect on higher harmonics and constant current output characteristic.
Example 2 the Compensation network is a series Compensation network
The primary side compensation network and the three secondary side compensation networks respectively comprise a compensation capacitor and a compensation inductor which is connected with the compensation capacitor in series.
As shown in fig. 3 (a), in the primary-side compensation network, a compensation inductor L11, a primary-side winding of the resolver, and a compensation capacitor C11 are connected in series in this order and then connected to a unidirectional full bridge.
In the three secondary side compensation networks, a compensation inductor (L21, L22 or L23), a secondary side winding of the rotary transformer and a compensation capacitor (C21, C22 or C23) are sequentially connected in series and then connected with an AC-AC converter circuit of a corresponding phase.
When the working frequency is equal to the resonant frequency, the resonant network is in a full resonance state, and the energy transmission efficiency is highest. The network can realize the forward and reverse transmission of power, the voltage gain is only related to the transformer transformation ratio when the network is in full resonance, and the characteristic that the voltage gain is 1 can be realized when the transformer transformation ratio is 1, thereby being beneficial to the bidirectional transmission of power. The network is used in situations where the direction of power transmission needs to be changed frequently.
The primary side compensation network and the three secondary side compensation networks respectively comprise a compensation inductor and two compensation capacitors. The two compensation capacitors are respectively a first compensation capacitor and a second compensation capacitor.
As shown in fig. 3 (b), in the primary-side compensation network, a first compensation capacitor C11 is connected in parallel to both ends of the primary-side winding of the rotary transformer, and a compensation inductor L11, the primary-side winding of the rotary transformer, and a second compensation capacitor C12 are connected in series in sequence and then connected to a unidirectional full bridge.
In the three secondary-side compensation networks, each first compensation capacitor (C21, C23 or C25) is connected in parallel with two ends of a secondary winding of the rotary transformer, and a compensation inductor (L21, L22 or L23), the secondary winding of the rotary transformer and a second compensation capacitor (C22, C24 or C26) are sequentially connected in series and then connected with an AC-AC converter circuit of a corresponding phase.
Compared with a parallel compensation topological structure, the LCC compensation structure has the advantage that a blocking capacitor is connected in series in a transformer winding branch. In the topology, a coil winding is connected with a blocking capacitor in series and then connected with a compensation capacitor in parallel, and the compensation inductor is connected with the blocking capacitor and the winding in series. The value of the compensation inductor is the same as the inductance value of the blocking capacitor and the transformer coil after resonance.
The structure is improved on the basis of a parallel resonance structure, has the advantage of high stability of a parallel compensation topology, has higher transmission power than the parallel compensation topology, and may have higher transmission power than a series resonance structure under a specific coupling coefficient. And meanwhile, the resonant frequency of the topology is not influenced by the coupling coefficient and the load condition, so that the control of the topology is simpler. The requirement of the topology on the withstand voltage of the resonant capacitor is low, and the topology can be used in occasions with high voltage levels.
The three-phase AC-AC frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
Among them, the three-phase ac/ac converter circuit preferably has the following three embodiments.
Embodiment 1 the three-phase AC-AC frequency conversion circuit is a three-phase full-bridge circuit
As shown in fig. 2, the three-phase full-bridge circuits are an a-phase full-bridge circuit, a B-phase full-bridge circuit, and a C-phase full-bridge circuit, respectively.
Each phase of full-bridge circuit comprises four bidirectional switches in an H-bridge structure. Each bidirectional switch comprises two switching tubes with anti-parallel diodes which are connected in series in an opposite direction.
Since the circuit topology structures of the three-phase full-bridge circuit are the same, the invention takes the A-phase full-bridge circuit as an example for explanation.
The first bidirectional switch in the A-phase full-bridge circuit is mainly formed by connecting a switch tube S21 with an anti-parallel diode and a switch tube S22 with an anti-parallel diode in an anti-series mode.
The second bidirectional switch in the A-phase full-bridge circuit is mainly formed by connecting a switch tube S25 with an anti-parallel diode and a switch tube S26 with an anti-parallel diode in an anti-series mode.
A first bidirectional switch and a second bidirectional switch in the A-phase full-bridge circuit form a first bridge arm, and the midpoint of the first bridge arm is connected with one end of a secondary side compensation network.
The third bidirectional switch in the A-phase full-bridge circuit is mainly formed by connecting a switch tube S23 with an anti-parallel diode and a switch tube S24 with an anti-parallel diode in an anti-series mode.
The fourth bidirectional switch in the A-phase full-bridge circuit is mainly formed by connecting a switch tube S27 with an anti-parallel diode and a switch tube S28 with an anti-parallel diode in an anti-series mode.
And a third bidirectional switch and a fourth bidirectional switch in the A-phase full-bridge circuit form a second bridge arm, and the midpoint of the second bridge arm is connected with the other end of the secondary side compensation network.
In fig. 2, since the secondary side compensation network adopts the parallel compensation network in embodiment 1, the midpoint of the first arm is connected in series with the compensation inductor L21 and the secondary side winding in sequence and then connected to the midpoint of the second arm. The compensation capacitor C21 is connected in parallel across the secondary winding. Alternatively, the secondary side compensation network may also adopt the topology of embodiment 2 or embodiment 3.
Eight power electronic power switches forming four bidirectional switches in the B-phase full bridge circuit are respectively S29-S216.
Eight power electronic power switches forming four bidirectional switches in the C-phase full-bridge circuit are respectively S217-S224.
The circuit topology structures of the B-phase full bridge circuit and the C-phase full bridge circuit refer to the a-phase full bridge circuit, and are not described herein again.
The three-phase full-bridge AC-AC frequency conversion circuit composed of the bidirectional switches is a commonly used AC-AC frequency conversion circuit, the circuit structure uses a large number of switch tubes, but the voltage resistance requirement on a single switch tube is reduced, and the three-phase full-bridge AC-AC frequency conversion circuit can be used in most application occasions.
Embodiment 2 the three-phase AC-AC frequency conversion circuit is a circuit with an anti-parallel H bridge, also called three-phase anti-parallel H bridge
As shown in fig. 4 (a), the three-phase anti-parallel H-bridge includes an a-reverse parallel H-bridge, a B-reverse parallel H-bridge, and a C-reverse parallel H-bridge.
Each intersected alternating frequency circuit, namely each inverse parallel H bridge, comprises two inverse parallel H bridges, and each H bridge comprises four switching tubes.
Because the circuit topological structures of the three-phase anti-parallel H-bridges are the same, the invention takes the A-phase anti-parallel H-bridge as an example for explanation.
The A-phase full bridge circuit consists of two H bridges connected in anti-parallel, wherein S21, S22, S23 and S24 form a forward H bridge, and S25, S26, S27 and S28 form a reverse H bridge.
The first bridge arm of the forward H bridge is formed by S21 and S22 in the forward H bridge; s23 and S24 form the second leg of the forward H bridge.
The first bridge arm of the forward H bridge is formed by S25 and S26 in the reverse H bridge; s27 and S28 form the second leg of the forward H bridge.
The middle point of the first bridge arm of the forward H bridge is connected with the middle point of the second bridge arm of the reverse H bridge, and is simultaneously connected with one end of the secondary side compensation network; the middle point of the second bridge arm of the forward H bridge is connected with the middle point of the first bridge arm of the reverse H bridge, and meanwhile, the middle point of the second bridge arm of the forward H bridge is connected with the other end of the secondary compensation network.
The positive H bridge and the reverse H bridge are in a reverse parallel structure, the output positive pole of the positive H bridge is connected with the output negative pole of the reverse H bridge to form one end of the phase A output, and the output negative pole of the positive H bridge is connected with the output positive pole of the reverse H bridge to form the other end of the phase A output.
The secondary side compensation network in this embodiment can take various configurations, and the configuration in embodiment 1 will be described below.
The compensation network structure in embodiment 1 is a parallel compensation network, so that the first arm of the forward H-bridge is connected to the midpoint of the second arm of the reverse H-bridge, and then connected to the compensation inductor L21 and the secondary winding in series, and finally connected to the second arm of the forward H-bridge and the first arm of the reverse H-bridge. The compensation capacitor C21 is connected in parallel across the secondary winding. Alternatively, the secondary side compensation network may also adopt the topology of embodiment 2 or embodiment 3.
And B, eight power electronic power switches which form a forward H bridge and a reverse H bridge in the reverse parallel H bridge circuit are respectively S29-S216.
Eight power electronic power switches forming a forward H bridge and a reverse H bridge in the C reverse parallel H bridge circuit are respectively S217-S224.
The circuit topology structure of the reverse parallel H-bridge circuit B and the reverse parallel H-bridge circuit C refers to the reverse parallel H-bridge circuit A, and the description is omitted here.
The switch tube used in the AC-AC frequency conversion circuit formed by the anti-parallel H bridge does not need an anti-parallel diode, thereby reducing the number of power elements. The circuit is usually made by cosine wave cross-cut control method, has low power factor, and is not suitable for high frequency occasions, and is generally used in low frequency and high power occasions with frequency below kilohertz and power above kilowatt level.
As shown in fig. 4 (B), the three-phase matrix converters are an a-phase matrix converter, a B-phase matrix converter, and a C-phase matrix converter, respectively.
The three-phase matrix converter is formed by arranging nine groups of bidirectional switches in a 3 x 3 matrix form. Each bidirectional switch comprises two switching tubes which are connected in series in an opposite direction and provided with anti-parallel diodes.
Since the circuit topology of the three-phase matrix converter is the same, the invention will be described by taking the a-phase matrix converter as an example.
The A-phase matrix converter consists of three bidirectional switches. Each bidirectional switch is formed by reversely connecting two switch tubes with anti-parallel diodes in series. Wherein S21 and S22 form the first bidirectional switch of phase a of the matrix converter, S23 and S24 form the second bidirectional switch of phase a of the matrix converter, and S25 and S26 form the third bidirectional switch of phase a of the matrix converter.
The input end of the bidirectional switch is connected with the secondary side compensation network, and the output end of the bidirectional switch is connected with the winding motor rotor.
The input end of a first bidirectional switch of the A-phase matrix converter is connected with a first phase output of a three-phase output of the secondary side compensation network; the input end of the second bidirectional switch is connected with the second phase output of the secondary side compensation network three-phase output; and the input end of the third bidirectional switch is connected with the third phase output of the secondary side compensation network three-phase output.
The output ends of three bidirectional switches in the A-phase matrix converter are mutually connected to form an A-phase output of the matrix converter and are directly connected with an A-phase winding of a winding motor rotor.
Six power electronic power switches forming three bidirectional switches in the B-phase matrix converter are respectively S27-S212.
Six power electronic power switches forming three bidirectional switches in the C-phase matrix converter are respectively S213-S218.
The circuit topology structures of the B-phase matrix converter and the C-phase matrix converter refer to the a-phase matrix converter, and are not described herein again.
The matrix converter composed of bidirectional switches is a novel AC-AC frequency conversion circuit, which can convert electric energy of any voltage and frequency into electric energy of another voltage and frequency, and has the characteristics of good output current waveform, high input power factor and bidirectional power flow. The topological structure can be used in various occasions needing electric energy conversion.
Further, the switching elements in the three-phase full-bridge circuit, the single-phase full-bridge circuit, and the three-phase ac/ac converter circuit are all power semiconductor switching devices, and the types of the power semiconductor switching devices are preferably IGBTs, MOSFETs, SiC-MOSFETs, or the like.
The control system comprises a controller 1, a controller 2 and a wireless information transmission module.
The controller 1 is respectively connected with a power grid, a three-phase full-bridge circuit and a single-phase full-bridge circuit and can collect primary side electric quantity information. The primary side electric quantity information comprises a voltage current signal of a power grid and a direct current bus voltage.
The controller 2 is respectively connected with the three-phase AC/AC frequency conversion circuit and the winding motor rotor and can collect secondary side electric quantity information. And the secondary side electrical quantity information comprises voltage and current of a wound motor rotor, rotor rotating speed and rotor torque.
The controller 1 communicates with the controller 2 through a wireless information transmission module.
The controller 1 controls the three-phase full bridge circuit through the collected primary side electric quantity information, so that the voltage of the direct current bus is kept stable; on the other hand, the single-phase full bridge circuit is controlled by combining the secondary side electric quantity information fed back by the controller 2, so that the direct current is changed into high-frequency alternating current with different duty ratios, and the effect of controlling the transmission power is achieved.
The controller 2 controls the three-phase AC/AC frequency conversion circuit by collecting the secondary side electric quantity information and combining with the primary side electric quantity information fed back by the controller 1, and provides low-frequency alternating current with the frequency not more than one hundred hertz for the winding motor rotor, so that the winding motor rotor can stably run.
The controller 1 and the controller 2 each include an information sampling module, an information processing module, and a driving module. The information sampling module comprises a voltage and current sampling module and a rotating speed and torque detection module. The information processing module adopts a DSP control chip. The driving module changes the control signal into a switching tube driving signal.
A three-phase full-bridge circuit, a single-phase full-bridge circuit, a primary side compensation network, a fixed iron core and a fixed winding of a rotary transformer and a controller 1 in a main circuit system form a fixed part of a wireless power supply system; a secondary side compensation network, a three-phase AC-AC frequency conversion circuit, a rotary iron core and a rotary winding of a rotary transformer and a controller 2 in a main circuit system form a rotary part of a wireless power supply system; the fixed part is fixed through an external support in a limited mode, the rotating part is fixed on a rotating shaft of a winding motor rotor, and the rotating part rotates along with the winding motor rotor when the wireless power supply system works.
Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the embodiments, and various equivalent modifications can be made within the technical spirit of the present invention, and the scope of the present invention is also within the scope of the present invention.
Claims (9)
1. The utility model provides a wireless power supply system of electric motor rotor which characterized in that: comprises a main circuit system and a control system;
the main circuit system comprises a three-phase full-bridge circuit, a single-phase full-bridge circuit, a magnetic coupling resonance network, an AC-AC frequency conversion circuit and a wound motor rotor;
a three-phase full-bridge circuit in the main circuit system is directly connected with a power grid; the three-phase full-bridge circuit is connected with the single-phase full-bridge circuit through a filter capacitor; the single-phase full-bridge circuit is connected with the magnetic coupling resonance network; the magnetic coupling resonance network comprises a primary side compensation network, a rotary transformer and three secondary side compensation networks; the primary side compensation network is connected with a fixed winding in the rotary transformer to form single-phase input; the three secondary side compensation networks are respectively connected with a rotary winding in the rotary transformer to form three-phase output;
the three-phase output is respectively connected with the three-phase AC-AC frequency conversion circuit; the three-phase AC-AC frequency conversion circuit is directly connected with a three-phase winding of a winding motor rotor;
the control system comprises a controller 1, a controller 2 and a wireless information transmission module;
the controller 1 is respectively connected with a power grid, a three-phase full-bridge circuit and a single-phase full-bridge circuit and can collect primary side electric quantity information; the primary side electric quantity information comprises a voltage current signal of a power grid and a direct current bus voltage;
the controller 2 is respectively connected with the three-phase AC/AC frequency conversion circuit and the winding motor rotor and can collect secondary side electric quantity information; the secondary side electrical quantity information comprises voltage and current of a winding motor rotor, rotor rotating speed and rotor torque;
the controller 1 communicates with the controller 2 through a wireless information transmission module;
the controller 1 controls the three-phase full bridge circuit through the collected primary side electric quantity information, so that the voltage of the direct current bus is kept stable; on the other hand, the single-phase full bridge circuit is controlled by combining the secondary side electric quantity information fed back by the controller 2, so that the direct current is changed into high-frequency alternating current with different duty ratios, and the effect of controlling the transmission power is achieved;
the controller 2 controls the three-phase AC/AC frequency conversion circuit by collecting the secondary side electric quantity information and combining the primary side electric quantity information fed back by the controller 1, and provides low-frequency AC power for the winding motor rotor, so that the winding motor rotor can stably run.
2. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the three-phase AC-AC frequency conversion circuit consists of three-phase independent full-bridge circuits; each phase of full-bridge circuit consists of four bidirectional switches connected in an H-bridge structure; each bidirectional switch is formed by reversely connecting two switch tubes with anti-parallel diodes in series; the three-phase alternating-current and alternating-current frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
3. The wireless power supply system for the rotor of the motor according to claim 1, wherein: each crossed alternating frequency circuit in the three-phase alternating frequency conversion circuit comprises two H bridges which are connected in an anti-parallel mode, and each H bridge comprises four switching tubes; the three-phase alternating-current and alternating-current frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
4. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the three-phase AC-AC frequency conversion circuit is a three-phase matrix converter which is formed by arranging nine groups of bidirectional switches in a 3 multiplied by 3 matrix form; each bidirectional switch comprises two switching tubes which are connected in series in an opposite direction and provided with anti-parallel diodes; the three-phase alternating-current and alternating-current frequency conversion circuit, the three-phase output of the magnetic coupling resonance network and the three-phase rotor winding of the wound motor rotor are connected in series to form a secondary side of the main circuit system.
5. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the primary side compensation network and the three secondary side compensation networks are all parallel compensation structures and respectively comprise a compensation capacitor and a compensation inductor; in the primary side compensation network, a compensation capacitor is connected in parallel at two ends of a primary side winding of a rotary transformer, and a compensation inductor is connected with the primary side winding of the rotary transformer in series and then connected with a unidirectional full bridge; in the three secondary side compensation networks, each compensation capacitor is connected in parallel at two ends of the secondary side winding of the rotary transformer, and the compensation inductor is connected with the secondary side winding of the rotary transformer in series and then connected with the AC-AC frequency conversion circuit of the corresponding phase.
6. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the primary side compensation network and the three secondary side compensation networks respectively comprise a compensation capacitor and a compensation inductor which is connected with the compensation capacitor in series.
7. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the primary side compensation network and the three secondary side compensation networks are all LCC compensation structures and respectively comprise a compensation inductor and two compensation capacitors; the two compensation capacitors are respectively a first compensation capacitor and a second compensation capacitor; in the primary side compensation network, a first compensation capacitor is connected in parallel at two ends of a primary side winding of a rotary transformer, and a compensation inductor, the primary side winding of the rotary transformer and a second compensation capacitor are sequentially connected in series and then connected with a unidirectional full bridge; in the three secondary side compensation networks, each first compensation capacitor is connected in parallel at two ends of the secondary side winding of the rotary transformer, and the compensation inductor, the secondary side winding of the rotary transformer and the second compensation capacitor are sequentially connected in series and then connected with the AC-AC frequency conversion circuit of the corresponding phase.
8. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the switching elements in the three-phase full-bridge circuit, the single-phase full-bridge circuit and the three-phase AC-AC frequency conversion circuit are all power semiconductor switching devices, and the types of the power semiconductor switching devices are IGBT, MOSFET or SiC-MOSFET.
9. The wireless power supply system for the rotor of the motor according to claim 1, wherein: the controller 1 and the controller 2 both comprise an information sampling module, an information processing module and a driving module; the information sampling module comprises a voltage and current sampling module and a rotating speed and torque detection module; the information processing module adopts a DSP control chip; the driving module changes the control signal into a switching tube driving signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010596368.4A CN111817449B (en) | 2020-06-28 | 2020-06-28 | Wireless power supply system for motor rotor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010596368.4A CN111817449B (en) | 2020-06-28 | 2020-06-28 | Wireless power supply system for motor rotor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111817449A true CN111817449A (en) | 2020-10-23 |
| CN111817449B CN111817449B (en) | 2021-11-16 |
Family
ID=72855442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010596368.4A Active CN111817449B (en) | 2020-06-28 | 2020-06-28 | Wireless power supply system for motor rotor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111817449B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113078742A (en) * | 2021-03-26 | 2021-07-06 | 武汉理工大学 | Wireless power transmission device with bilateral speed measurement function |
| CN113098357A (en) * | 2021-03-26 | 2021-07-09 | 西安交通大学 | Switched reluctance motor drive control system and control method |
| CN113555969A (en) * | 2021-07-26 | 2021-10-26 | 湖北理工学院 | Multi-load inductive power transmission analysis method based on LCC-S type compensation |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1925277A (en) * | 2005-08-29 | 2007-03-07 | 丁振荣 | Alternating current synchronous motor based on three-phase rotary transformer technology, alternating current wound rotor motor and arrangements for speed regulation |
| US20080106237A1 (en) * | 2003-10-20 | 2008-05-08 | Yvan Lafontaine | Off road vehicle steering wheel switch powering |
| CN101795081A (en) * | 2010-03-03 | 2010-08-04 | 中国科学院电工研究所 | Power electronic transformer having multi-winding isolation transformer |
| CN102710201A (en) * | 2012-05-30 | 2012-10-03 | 南京航空航天大学 | Third harmonic power supply and controlled rotary transformation wind power generating unit as well as brushless excitation method |
| JP2015115017A (en) * | 2013-12-15 | 2015-06-22 | 眞生 貝塚 | Sensor signal propagation device of rotor |
| CN106300702A (en) * | 2016-11-04 | 2017-01-04 | 北京恒泰万博石油技术股份有限公司 | Non-contact electric energy transmission system and the application in the rotary steering mechanism of down-hole thereof |
| CN109767902A (en) * | 2019-01-29 | 2019-05-17 | 河海大学 | A kind of high-power high-frequency rotating electric electronic transformer |
| CN210167861U (en) * | 2019-08-19 | 2020-03-20 | 南京航空航天大学 | Multichannel non-contact power supply system with fundamental wave-harmonic wave parallel energy transfer function |
-
2020
- 2020-06-28 CN CN202010596368.4A patent/CN111817449B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080106237A1 (en) * | 2003-10-20 | 2008-05-08 | Yvan Lafontaine | Off road vehicle steering wheel switch powering |
| CN1925277A (en) * | 2005-08-29 | 2007-03-07 | 丁振荣 | Alternating current synchronous motor based on three-phase rotary transformer technology, alternating current wound rotor motor and arrangements for speed regulation |
| CN101795081A (en) * | 2010-03-03 | 2010-08-04 | 中国科学院电工研究所 | Power electronic transformer having multi-winding isolation transformer |
| CN102710201A (en) * | 2012-05-30 | 2012-10-03 | 南京航空航天大学 | Third harmonic power supply and controlled rotary transformation wind power generating unit as well as brushless excitation method |
| JP2015115017A (en) * | 2013-12-15 | 2015-06-22 | 眞生 貝塚 | Sensor signal propagation device of rotor |
| CN106300702A (en) * | 2016-11-04 | 2017-01-04 | 北京恒泰万博石油技术股份有限公司 | Non-contact electric energy transmission system and the application in the rotary steering mechanism of down-hole thereof |
| CN109767902A (en) * | 2019-01-29 | 2019-05-17 | 河海大学 | A kind of high-power high-frequency rotating electric electronic transformer |
| CN210167861U (en) * | 2019-08-19 | 2020-03-20 | 南京航空航天大学 | Multichannel non-contact power supply system with fundamental wave-harmonic wave parallel energy transfer function |
Non-Patent Citations (4)
| Title |
|---|
| RICCARDO TREVISAN 等: ""A 1-kW Contactless Energy Transfer System Based on a Rotary Transformer for Sealing Rollers"", 《 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 》 * |
| STEFAN DITZE 等: ""Inductive power transfer system with a rotary transformer for contactless energy transfer on rotating applications"", 《2016 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS)》 * |
| 沈训欢 等: ""无接触式旋转变压器的设计及仿真"", 《防爆电机》 * |
| 王宝栋: ""基于旋转变压器的无刷双馈电机降阶模型研究"", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113078742A (en) * | 2021-03-26 | 2021-07-06 | 武汉理工大学 | Wireless power transmission device with bilateral speed measurement function |
| CN113098357A (en) * | 2021-03-26 | 2021-07-09 | 西安交通大学 | Switched reluctance motor drive control system and control method |
| CN113555969A (en) * | 2021-07-26 | 2021-10-26 | 湖北理工学院 | Multi-load inductive power transmission analysis method based on LCC-S type compensation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111817449B (en) | 2021-11-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111817449B (en) | Wireless power supply system for motor rotor | |
| CN100399685C (en) | Filter | |
| Mecke et al. | High frequency resonant inverter for contactless energy transmission over large air gap | |
| Tan et al. | Topology and application of bidirectional isolated dc-dc converters | |
| CN1117422C (en) | High-frequency AC/AC converter with AC link | |
| CN103269178B (en) | Single-stage type isolated type three-phase two-way AC/DC converter and control method thereof | |
| CN110920422B (en) | High-power electric vehicle charging device based on current source and control method | |
| CN102624277A (en) | Dead-zone-free three-phase AC/DC converter with high-frequency rectifier bridge | |
| CN102158072A (en) | Power inverter of parallel-connected electric bridge type impedance network | |
| CN102969860A (en) | Multi-phase brushless double-fed motor and frequency converting control system | |
| CN109088410B (en) | Phase 360-degree orthogonal direct power flow controller and working method thereof | |
| CN108448923B (en) | Frequency conversion control method for realizing soft switch of three-phase inverter | |
| CN102185491B (en) | Serial and parallel connection electrical bridge type impedance network power converter | |
| CN101860245A (en) | Medium-power two-stage three-phase static converter | |
| CN213817574U (en) | Ripple suppression rectifier based on coupling inductor | |
| CN1222100C (en) | Great-power switching voltage regulator with no electromagnetic pollution | |
| EP4308410A1 (en) | Motor drive integrated on-board charger for electric vehicle and control method thereof | |
| CN209767394U (en) | self-following flying capacitor five-level AC-AC converter | |
| CN108023484B (en) | A kind of multi-modal high-frequency resonant charging circuit | |
| CN209845399U (en) | Variable-frequency dimmer based on Vienna PFC and full-bridge inverter circuit | |
| CN206164115U (en) | Wind power generation micro inverter device | |
| CN210273854U (en) | MMC-based three-phase-single-phase current converter without power frequency transformer | |
| CN2532655Y (en) | High-efficient frequency-changing electric heater | |
| CN112019062B (en) | Sine wave high-frequency chain three-level lithium battery inverter capable of realizing energy feedback | |
| CN203014699U (en) | Single phase four-quadrant current transformer with DC active filter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |