A single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device and method

Abstract

The present invention belongs to the technical field of inductive wireless charging and relates to a single-tube P-CLC frequency-switching constant current and constant voltage wireless charging device and method. AC power is rectified by a first power-frequency rectifier bridge and filtered by a first power-frequency filter capacitor before being converted into DC power. Direct current is then inverted into high-frequency AC power by a first compensation network, a transmitting coil, a receiving coil, and a second compensation network. The high-frequency AC power is then converted into DC power by a second high-frequency rectifier bridge, a first high-frequency filter inductor, and a second high-frequency filter capacitor to charge a battery. When the battery voltage rises to a set value, the switching frequency is switched, converting charging from a constant current mode to a constant voltage mode. The circuit has a simple structure, safe and reliable operation, low switching loss, low cost, and high efficiency. The switching frequency can be switched within a narrow frequency band to achieve constant current and constant voltage charging of the battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of inductive wireless charging and relates to a single-tube P-CLC (P-type compensation at the transmitting end and CLC compensation at the receiving end, referred to as P-CLC) variable frequency switching constant current and constant voltage wireless charging device and method. The device enables the single-tube circuit to perform variable frequency switching constant current and constant voltage charging within a narrow frequency band, eliminating the four switching tubes, additional control circuits, and complex closed-loop control process of a full-bridge circuit. Background Art

[0002] Currently, most research on constant current-constant voltage compensation topologies for inductively powered power transfer (IPT) systems is based on full-bridge inverter topologies. Due to the particularity of the single-tube LC resonant inverter circuit structure, the existing compensation networks and design methods applicable to full-bridge circuits are not applicable to single-tube circuits. Compared to single-tube LC resonant inverter circuits, full-bridge voltage-type inverter circuits have a relatively complex structure. The switching tubes in the upper and lower bridge arms are prone to burnout due to direct conduction. They have many switching devices, complex control, high switching losses, and high operating costs. Therefore, it is urgent to introduce a new P-CLC compensation topology on a single-tube circuit and, through reasonable compensation network parameter design, enable it to fully achieve mode switching between constant current and constant voltage on a single-tube circuit by switching the operating frequency within a narrow range, thereby providing great research and application development value for the output of constant current-constant voltage compensation topology on a single-tube circuit. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the existing technology, and to design and propose a single-tube P-CLC frequency conversion switching constant current and constant voltage wireless charging device and method, to fill the current research gap that cannot use a single-tube circuit to achieve a narrow frequency band down-conversion to achieve constant current and constant voltage output. By changing the operating frequency from the operating frequency f in the constant current mode to the operating frequency f in the constant current mode, the device can realize the constant current and constant voltage output. CC Switch to constant voltage mode and the operating frequency f CV The method for switching from a constant current output mode to a constant voltage output mode is realized, eliminating the need for a mode switch and a corresponding control circuit for switching topology.

[0004] In order to achieve the above-mentioned purpose, the main structure of the single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device of the present invention includes a first power frequency rectifier bridge, a first power frequency filter capacitor, a first compensation network, a transmitting coil, a receiving coil, a second compensation network, a second high-frequency rectifier bridge, a first high-frequency filter inductor, a second high-frequency filter capacitor, a battery, a secondary side detection circuit and a primary side control circuit, wherein the primary side control circuit 10 is composed of a primary side auxiliary power supply, a primary side single-chip microcomputer control circuit, a primary side wireless communication circuit, a primary side voltage detection circuit and a switch tube drive circuit, and the secondary side detection circuit is composed of a secondary side auxiliary power supply, a secondary side single-chip microcomputer control circuit, a secondary side wireless communication circuit, a primary side voltage detection circuit and a switch tube drive circuit. The invention is composed of a circuit, a voltage sampling circuit and a current sampling circuit. The input end of the first power frequency rectifier bridge is connected to the AC power supply, and the output end is connected to the input end of the first power frequency filter capacitor. The AC power is rectified by the first power frequency rectifier bridge and filtered by the first power frequency filter capacitor in sequence, and then converted into DC power to power the main circuit; the output end of the first power frequency filter capacitor is connected to the input end of the first compensation network, the switch tube and the diode are connected to the first compensation network, the output end of the first compensation network is connected to the transmitting coil, and the input end of the second compensation network is connected to the receiving coil. The direct current passes through the first compensation network, the transmitting coil, the receiving coil, and the second compensation network in sequence, and then passes through the switch tube. The LC resonance formed after the opening and closing of the clamping and the closing of the capacitor inverts the DC power into high-frequency AC power. The output end of the second compensation network is connected to the input end of the second high-frequency rectifier bridge. The second high-frequency rectifier bridge, the first high-frequency filter inductor, and the second high-frequency filter capacitor are connected in sequence. The battery is connected to the output end of the second high-frequency filter capacitor. The high-frequency AC power is converted into DC power in sequence through the second high-frequency rectifier bridge, the first high-frequency filter inductor, and the second high-frequency filter capacitor to charge the battery. The primary auxiliary power supply is respectively connected to the first power frequency filter capacitor, the first compensation network, the primary single-chip microcomputer control circuit, the primary wireless communication circuit, the primary voltage detection circuit, and the switch tube drive circuit. The primary voltage detection circuit is connected to the diode, the switch tube drive circuit is connected to the switch tube, the primary side single-chip microcomputer control circuit is respectively connected to the primary side wireless communication circuit, the primary side voltage detection circuit and the switch tube drive circuit; the battery is respectively connected to the voltage sampling circuit, the current sampling circuit and the secondary side auxiliary power supply, the secondary side single-chip microcomputer control circuit is respectively connected to the secondary side auxiliary power supply, the secondary side wireless communication circuit, the voltage sampling circuit and the current sampling circuit, and the secondary side auxiliary power supply is respectively connected to the voltage sampling circuit, the current sampling circuit and the secondary side wireless communication circuit. When the voltage of the battery rises to the set value, the switching frequency is switched, and the charging is converted from constant current mode to constant voltage mode.

[0005] The specific process of realizing constant current-constant voltage charging in the present invention is as follows:

[0006] (1) Starting the AC power supply, the AC power is rectified and filtered by the first power frequency rectifier bridge and the first power frequency filter capacitor to supply power to the primary auxiliary power supply, so that the primary control circuit can work normally; the battery supplies power to the secondary auxiliary power supply, so that the secondary status detection circuit can work normally;

[0007] (2) Set the initial state to constant current charging mode to charge the battery. The switching frequency in this mode is f CC , and in this stage, the secondary side single chip microcomputer control circuit first converts the voltage signal collected by the voltage sampling circuit into digital-to-analog conversion. When it is determined that the collected voltage signal is lower than the output value set in the constant voltage mode, the secondary side wireless communication circuit does not send the state switching instruction to the primary side wireless communication circuit. Then the current sampling circuit converts the collected signal into digital-to-analog conversion and fine-tunes the operating frequency f by sending the expected CC The instruction is received and processed by the primary side wireless communication circuit and the primary side single chip control circuit, so that the switch tube drive circuit sends the switch tube drive PWM waveform of the expected frequency, thereby keeping the output current constant;

[0008] (3) In the constant current charging mode, when it is detected that the terminal voltage of the battery reaches the set switching value, the voltage sampling circuit collects the voltage signal and after it is processed by the secondary side single chip microcomputer control circuit, the secondary side wireless communication circuit sends a state switching instruction to the primary side wireless communication circuit. At this time, the circuit will switch from constant current charging to constant voltage charging. The secondary side single chip microcomputer control circuit and the secondary side wireless communication circuit feed back the voltage signal collected by the voltage sampling circuit to the primary side wireless communication circuit and the primary side single chip microcomputer control circuit, and fine-tune the operating frequency f according to the expected setting. CV The program makes the output voltage constant;

[0009] (4) During the constant voltage charging stage, when it is detected that the battery current drops to the minimum charging current value for battery charging, it proves that charging is completed. At this time, the secondary side microcontroller control circuit and the secondary side wireless communication circuit send a stop command; after the primary side wireless communication circuit and the primary side microcontroller control circuit receive the stop command, they terminate the generation of the PWM waveform, causing the switch tube drive circuit to stop sending the PWM pulse signal, and charging is completed.

[0010] Compared with the prior art, the present invention has a simple circuit structure, safe and reliable operation, low switching loss, low cost, high efficiency, and can switch the switching frequency within a narrow frequency band to achieve the constant current-constant voltage charging requirement for the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a circuit structure principle diagram of the single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device described in the present invention.

[0012] Figure 2This is a schematic diagram of the working process of the single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device described in the present invention.

[0013] Figure 3 This is the mutual inductance equivalent model under the constant current mode of the present invention.

[0014] Figure 4 This is the mutual inductance equivalent model under the constant voltage mode of the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific implementation methods.

[0016] Example:

[0017] The main structure of the single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device described in this embodiment includes a first power frequency rectifier bridge 1, a first power frequency filter capacitor 2, a first compensation network 3, a transmitting coil Lp, a receiving coil Ls, a second compensation network 4, a second high-frequency rectifier bridge 5, a first high-frequency filter inductor 6, a second high-frequency filter capacitor 7, a battery 8, a secondary side detection circuit 9 and a primary side control circuit 10, wherein the primary side control circuit 10 is composed of a primary side auxiliary power supply 16, a primary side single-chip microcomputer control circuit 19, a primary side wireless communication circuit 17, a primary side voltage detection circuit 18 and a switch tube The drive circuit 20 is composed of a secondary detection circuit 9, which is composed of a secondary auxiliary power supply 13, a secondary single-chip microcomputer control circuit 15, a secondary wireless communication circuit 14, a voltage sampling circuit 11 and a current sampling circuit 12. The input end of the first power frequency rectifier bridge 1 is connected to the AC power supply AC, and the output end is connected to the input end of the first power frequency filter capacitor 2. The AC power is rectified by the first power frequency rectifier bridge 1 and filtered by the first power frequency filter capacitor 2, and then converted into DC power to power the main circuit; the output end of the first power frequency filter capacitor 2 is connected to the input end of the first compensation network 3, and the switch tube Q and the diode D QThe first compensation network 3 is connected to the output end of the first compensation network 3, and the transmitting coil Lp is connected to the input end of the second compensation network 4. The receiving coil Ls is connected to the input end of the second compensation network 4. After the direct current passes through the first compensation network 3, the transmitting coil Lp, the receiving coil Ls, and the second compensation network 4 in sequence, the DC power is inverted into high-frequency AC power through the LC resonance formed by the opening and closing of the switch tube Q. The output end of the second compensation network 4 is connected to the input end of the second high-frequency rectifier bridge 5. The second high-frequency rectifier bridge 5, the first high-frequency filter inductor 6, and the second high-frequency filter capacitor 7 are connected in sequence. The battery 8 is connected to the output end of the second high-frequency filter capacitor. The high-frequency AC power is converted into DC power in sequence through the second high-frequency rectifier bridge 5, the first high-frequency filter inductor 6, and the second high-frequency filter capacitor 7 to charge the battery 8. The primary auxiliary power supply 16 is respectively connected to the first power frequency filter capacitor 2, the first compensation network 3, the primary single-chip microcomputer control circuit 19, the primary wireless communication circuit 17, the primary voltage detection circuit 18 and the switch tube drive circuit 20. The primary voltage detection circuit 1 is connected to the diode D Q The primary side single-chip microcomputer control circuit 19 is respectively connected to the primary side wireless communication circuit 17, the primary side voltage detection circuit 18 and the switch tube driving circuit 20; the battery 8 is respectively connected to the voltage sampling circuit 11, the current sampling circuit 12 and the secondary side auxiliary power supply 13, the secondary side single-chip microcomputer control circuit 15 is respectively connected to the secondary side auxiliary power supply 13, the secondary side wireless communication circuit 14, the voltage sampling circuit 11 and the current sampling circuit 12, the secondary side auxiliary power supply 13 is respectively connected to the voltage sampling circuit 11, the current sampling circuit 12 and the secondary side wireless communication circuit 14. When the voltage of the battery 8 rises to the set value, the switching frequency is switched, and the charging is converted from constant current mode to constant voltage mode.

[0018] The specific process of implementing constant current-constant voltage charging in this embodiment is as follows:

[0019] (1) The AC power supply AC is started. After being rectified and filtered by the first power frequency rectifier bridge 1 and the first power frequency filter capacitor 2, the AC power is supplied to the primary auxiliary power supply 16, so that the primary control circuit 10 operates normally. The secondary auxiliary power supply 13 is supplied by the battery 8, so that the secondary status detection circuit 9 operates normally.

[0020] (2) Set the initial state to constant current charging mode to charge the battery 8. The switching frequency in this mode is f CC , and in this stage, the secondary side single chip control circuit 15 first converts the voltage signal collected by the voltage sampling circuit 11 into digital-to-analog conversion. When it is determined that the collected voltage signal is lower than the set output value of the constant voltage mode, the secondary side wireless communication circuit 15 does not send a state switching instruction to the primary side wireless communication circuit 17. Then the current sampling circuit 12 converts the collected signal into digital-to-analog conversion and sends the expected fine-tuning working frequency f CCThe instruction is received and processed by the primary wireless communication circuit 17 and the primary single-chip computer control circuit 19, so that the switch tube driving circuit 20 sends a switch tube driving PWM waveform of the expected frequency, thereby keeping the output current constant;

[0021] (3) In the constant current charging mode, when it is detected that the terminal voltage of the battery 8 reaches the set switching value, the voltage sampling circuit 11 collects the voltage signal and processes it through the secondary side single chip microcomputer control circuit 15. The secondary side wireless communication circuit 14 sends a state switching instruction to the primary side wireless communication circuit 17. At this time, the circuit will switch from constant current charging to constant voltage charging. The secondary side single chip microcomputer control circuit 15 and the secondary side wireless communication circuit 14 feed back the voltage signal collected by the voltage sampling circuit 11 to the primary side wireless communication circuit 17 and the primary side single chip microcomputer control circuit 19, and fine-tune the operating frequency f according to the expected setting. CV The program makes the output voltage constant;

[0022] (4) During the constant voltage charging stage, when it is detected that the current of the battery 8 drops to the minimum charging current value for battery charging, it proves that the charging is completed. At this time, the secondary side single-chip microcomputer control circuit 15 and the secondary side wireless communication circuit 14 send a stop command; after the primary side wireless communication circuit 17 and the primary side single-chip microcomputer control circuit 19 receive the stop command, they terminate the generation of the PWM waveform, causing the switch tube drive circuit 20 to stop sending the PWM pulse signal, and charging is completed.

[0023] In this embodiment, in the constant current charging mode, the circuit meets the following conditions:

[0024]

[0025] In constant voltage charging mode, the circuit only needs to meet the following conditions:

[0026]

[0027] Among them, ω CC is the operating angular frequency in constant current mode, ω CV is the operating angular frequency in constant voltage mode. The two operating angular frequencies can be controlled within a narrow frequency band.

[0028] The technologies not described in detail in this embodiment are all prior art.

Claims

1. A single-tube P-CLC variable frequency switching constant current and constant voltage wireless charging device, characterized in that The main structure includes a first power frequency rectifier bridge, a first power frequency filter capacitor, a first compensation network, a transmitting coil, a receiving coil, a second compensation network, a second high-frequency rectifier bridge, a first high-frequency filter inductor, a second high-frequency filter capacitor, a battery, a secondary side detection circuit and a primary side control circuit. The primary side control circuit is composed of a primary side auxiliary power supply, a primary side single-chip microcomputer control circuit, a primary side wireless communication circuit, a primary side voltage detection circuit and a switch tube drive circuit. The secondary side detection circuit is composed of a secondary side auxiliary power supply, a secondary side single-chip microcomputer control circuit, a secondary side wireless communication circuit, a voltage sampling circuit and a current sampling circuit. The input end of the first power frequency rectifier bridge is connected to the AC power supply, and the output end is connected to the input end of the first power frequency filter capacitor. The AC power is rectified by the first power frequency rectifier bridge and filtered by the first power frequency filter capacitor in sequence, and then converted into DC power to power the main circuit; the output end of the first power frequency filter capacitor is connected to the input end of the first compensation network, and the switch tube and the diode are connected to the first compensation network. The output end of the first compensation network is connected to the transmitting coil, and the input end of the second compensation network is connected to the receiving coil. The direct current passes through the first compensation network, the transmitting coil, the receiving coil, and the second compensation network in sequence, and then passes through the switch tube. The LC resonance formed after the opening and closing of the clamping and the closing of the capacitor converts the DC power into high-frequency AC power. The output end of the second compensation network is connected to the input end of the second high-frequency rectifier bridge. The second high-frequency rectifier bridge, the first high-frequency filter inductor, and the second high-frequency filter capacitor are connected in sequence. The battery is connected to the output end of the second high-frequency filter capacitor. The high-frequency AC power is converted into DC power in sequence through the second high-frequency rectifier bridge, the first high-frequency filter inductor, and the second high-frequency filter capacitor to charge the battery. The primary auxiliary power supply is respectively connected to the first power frequency filter capacitor, the first compensation network, the primary microcontroller control circuit, the primary wireless communication circuit, The primary side voltage detection circuit is connected to the switch tube drive circuit, the primary side voltage detection circuit is connected to the diode, the switch tube drive circuit is connected to the switch tube, and the primary side single-chip microcomputer control circuit is respectively connected to the primary side wireless communication circuit, the primary side voltage detection circuit and the switch tube drive circuit; the battery is respectively connected to the voltage sampling circuit, the current sampling circuit and the secondary side auxiliary power supply, the secondary side single-chip microcomputer control circuit is respectively connected to the secondary side auxiliary power supply, the secondary side wireless communication circuit, the voltage sampling circuit and the current sampling circuit, and the secondary side auxiliary power supply is respectively connected to the voltage sampling circuit, the current sampling circuit and the secondary side wireless communication circuit; The specific process of using the device to achieve constant current and constant voltage wireless charging is as follows: (1) Starting the AC power supply, the AC power is rectified and filtered by the first power frequency rectifier bridge and the first power frequency filter capacitor to supply power to the primary side auxiliary power supply, so that the primary side control circuit can work normally; The secondary side auxiliary power supply is powered by the battery, so that the secondary side status detection circuit can work normally; (2) Set the initial state to constant current charging mode to charge the battery. The switching frequency in this mode is f CC , and in this stage, the secondary side single chip microcomputer control circuit first converts the voltage signal collected by the voltage sampling circuit into digital-to-analog conversion. When it is determined that the collected voltage signal is lower than the output value set in the constant voltage mode, the secondary side wireless communication circuit does not send the state switching instruction to the primary side wireless communication circuit. Then the current sampling circuit converts the collected signal into digital-to-analog conversion and fine-tunes the operating frequency f by sending the expected CC The instruction is received and processed by the primary side wireless communication circuit and the primary side single chip control circuit, so that the switch tube drive circuit sends the switch tube drive PWM waveform of the expected frequency, thereby keeping the output current constant; (3) In constant current charging mode, the circuit meets the following conditions: where ω CC is the operating angular frequency in constant current mode. When it is detected that the terminal voltage of the battery reaches the set switching value, the voltage sampling circuit collects the voltage signal and processes it through the secondary side single-chip microcomputer control circuit. The secondary side wireless communication circuit sends a state switching instruction to the primary side wireless communication circuit. At this time, the circuit will switch from constant current charging to constant voltage charging. The secondary side single-chip microcomputer control circuit and the secondary side wireless communication circuit feed back the voltage signal collected by the voltage sampling circuit to the primary side wireless communication circuit and the primary side single-chip microcomputer control circuit, and fine-tune the operating frequency f according to the expected setting. CV The program makes the output voltage constant; (4) During the constant voltage charging stage, the circuit meets the following conditions: Among them, ω CV is the working angular frequency in constant voltage mode. When it is detected that the battery current drops to the minimum charging current value for battery charging, it proves that charging is completed. At this time, the secondary side microcontroller control circuit and the secondary side wireless communication circuit send a stop command; after the primary side wireless communication circuit and the primary side microcontroller control circuit receive the stop command, they terminate the generation of the PWM waveform, causing the switch tube drive circuit to stop sending the PWM pulse signal, and charging is completed.

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