A safe on-grid and off-grid control circuit for an electric energy feedback device

Abstract

The present invention discloses a safe on-grid and off-grid control circuit for an electric energy feedback device, which relates to the technical field of electric energy feedback, and includes an AC power grid module for providing electric energy and electric energy aggregation; an on-grid and off-grid module for rectification or inversion control; an auxiliary conversion module for performing resonance regulation, boost regulation or isolation high-frequency transformer rectification processing; a three-phase motor module for three-phase inversion processing and driving a three-phase motor to generate regenerative electric energy for rectification and high-voltage detection; an intelligent control module for signal reception and module control; a motor feedback module for driving a three-phase motor module to generate regenerative electric energy and output feedback electric energy; a low-voltage feedback module for electric energy superposition and three-phase inversion; and an energy storage control module for storing and discharging energy according to the voltage and power state of the low-voltage feedback module. The safe on-grid and off-grid control circuit for an electric energy feedback device of the present invention reduces the switching loss of the three-phase motor module, and improves the utilization rate of electric energy feedback and the safety of on-grid and off-grid connection.

Description

Technical Field

[0001] The invention relates to the technical field of electric energy feedback, and in particular to a safe on-grid and off-grid control circuit for an electric energy feedback device. Background Art

[0002] ‌Electric energy feedback device‌ is a device that can feed back the regenerative electric energy generated by the equipment during operation to the AC power grid. In order to perform safe on-grid and off-grid control, the regenerative electric energy generated by the equipment needs to be converted into synchronous AC electric energy, thereby achieving the effect of power saving. In the motor control, the electric energy feedback device in the prior art uses inverters, capacitors and other devices to perform DC-AC conversion processing, and then feeds back the regenerative electric energy generated by the motor braking process to the AC power grid. However, since the regenerative electric energy generated during the motor braking process is unstable, it is easy to cause a voltage drop when connected to the grid and off-grid, thereby reducing the power supply quality. Moreover, when the braking electric energy is lower than a certain voltage value, the power supply processing cannot continue, and the energy utilization rate is low, so it needs to be improved. Summary of the invention

[0003] The embodiment of the present invention provides a safe on-grid and off-grid control circuit for an electric energy feedback device to solve the problems raised in the above background technology.

[0004] According to an embodiment of the present invention, a safe on-grid and off-grid control circuit of an electric energy feedback device is provided, comprising: an AC power grid module, an on-grid and off-grid module, an auxiliary conversion module, a three-phase motor module, an intelligent control module, a motor feedback module, a low-voltage feedback module and an energy storage control module;

[0005] an AC power grid module, connected to the on-grid and off-grid module, the low-voltage feedback module and the motor feedback module, for providing a first AC power, receiving a second AC power output by the on-grid and off-grid module, a third AC power output by the low-voltage feedback module and a fourth AC power output by the motor feedback module;

[0006] The on-grid and off-grid module is connected to the intelligent control module and the auxiliary conversion module, and is used to rectify the AC power and output the first DC power, and when receiving the first inversion signal output by the intelligent control module, invert the third DC power output by the auxiliary conversion module and output the second AC power;

[0007] an auxiliary conversion module connected to the intelligent control module and the three-phase motor module, and configured to, upon receiving a first pulse signal output by the intelligent control module, perform resonance regulation processing on the first DC electric energy and output a second DC electric energy, upon receiving a third pulse signal output by the intelligent control module, perform voltage boost processing on the first regenerative electric energy generated by the three-phase motor module and output a third DC electric energy, and upon receiving a second pulse signal and a first rectification signal output by the intelligent control module, perform isolated high-frequency transformation and rectification processing on the first regenerative electric energy and output a first feedback electric energy;

[0008] A three-phase motor module, connected to the intelligent control module, for inverting the second DC electric energy and controlling the operation of the three-phase motor when receiving the second inversion signal output by the intelligent control module, generating the first regenerative electric energy after stopping receiving the second inversion signal, setting the high-voltage threshold and outputting the first detection signal when the first regenerative electric energy is greater than the high-voltage threshold;

[0009] An intelligent control module, connected to the energy storage control module, configured to output a second inverter signal and output a first pulse signal when outputting the second inverter signal, output the first inverter signal when stopping outputting the second inverter signal, output a third pulse signal when outputting the first inverter signal and receiving the first detection signal, output a second pulse signal and a first rectifier signal when outputting the first inverter signal and not receiving the first detection signal, and output a third inverter signal when outputting the first rectifier signal and receiving the second detection signal output by the energy storage control module;

[0010] The motor feedback module is used to receive the first AC power and drive the three-phase motor module to work, provide the second regenerative power when the three-phase motor stops working, perform inversion work and output the fourth AC power when the second regenerative power exceeds the high voltage threshold, and perform voltage conversion and output the second feedback power when the second regenerative power is lower than the high voltage threshold;

[0011] A low-voltage feedback module, connected to the intelligent control module, the auxiliary conversion module, the energy storage control module and the motor feedback module, for receiving the electric energy released by the energy storage control module, and when receiving the first feedback electric energy and the second feedback electric energy, superimposing the first feedback electric energy and the second feedback electric energy and outputting a fourth direct current electric energy, and when receiving the third inversion signal, inverting the fourth direct current electric energy or the electric energy released by the energy storage control module and outputting a third alternating current electric energy;

[0012] The energy storage control module is used to set a low-voltage threshold and a full-charge threshold, perform voltage sampling on the fourth DC electric energy and, when the sampling signal is less than the low-voltage threshold, output a second detection signal and store the fourth DC electric energy, perform power sampling on the stored electric energy and, when the sampled signal is greater than the full-charge threshold, release the stored electric energy.

[0013] As a further solution of the present invention: the AC power grid module includes an AC power grid; the on-grid and off-grid module includes a first inductor, a second inductor, a third inductor and a first converter; the intelligent control module includes a first controller;

[0014] Preferably, the first end of the AC power grid is connected to the first end of the first converter through a first inductor, the second end of the AC power grid is connected to the second end of the first converter through a second inductor, the third end of the AC power grid is connected to the third end of the first converter through a third inductor, the fourth and fifth ends of the first converter are connected to the auxiliary conversion module, and the sixth end of the first converter is connected to the IO1 end of the first controller.

[0015] As a further solution of the present invention: the auxiliary conversion module includes a first power tube, a second power tube, a fourth inductor, a first transformer, a first diode, a third power tube and a first thyristor;

[0016] Preferably, the drain of the first power tube is connected to the drain of the second power tube and the fourth end of the first converter, the source of the first power tube is connected to the drain of the third power tube, the cathode of the first diode and the second end of the primary side of the first transformer, and is connected to the source of the second power tube, the first end of the primary side of the first transformer and the three-phase motor module through the fourth inductor, the anode of the first diode is connected to the source of the third power tube and the fifth end of the first converter, the first end of the secondary side of the first transformer is connected to the anode of the first thyristor, the second end of the secondary side of the first converter and the cathode of the first thyristor are connected to the low-voltage feedback module, and the gate of the first power tube, the gate of the second power tube, the gate of the third power tube and the control end of the first thyristor are respectively connected to the IO4 end, IO6 end, IO7 end and IO8 end of the first controller.

[0017] As a further solution of the present invention: the three-phase motor module includes a first capacitor, a first resistor, a second resistor, a high-voltage detection device, a second converter and a three-phase motor;

[0018] Preferably, one end of the first capacitor is connected to the source of the second power tube and the first end of the first converter and is connected to the input end of the high-voltage detection device and one end of the second resistor through the first resistor, the other end of the first capacitor is connected to the other end of the second resistor, the second end of the second converter and the fifth end of the first converter, the third end, the fourth end and the fifth end of the second converter are respectively connected to the first end, the second end and the third end of the three-phase motor, and the output end of the high-voltage detection device and the sixth end of the second converter are respectively connected to the IO9 end and IO2 end of the first controller.

[0019] As a further solution of the present invention: the low-voltage feedback module includes a fifth inductor, a sixth inductor, a seventh inductor, a first inverter, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor; the motor feedback module includes a three-phase motor module control device;

[0020] Preferably, the first end of the first inverter is connected to the first end of the AC power grid and the first power supply end of the three-phase motor module control device through a fifth inductor, the second end of the first inverter is connected to the second end of the AC power grid and the second power supply end of the three-phase motor module control device through a sixth inductor, the third end of the first inverter is connected to the third end of the AC power grid and the third power supply end of the three-phase motor module control device through a seventh inductor, the fourth end of the first inverter is connected to the first end of the second capacitor, one end of the fifth capacitor, the cathode of the first thyristor and the energy storage control module, the other end of the fifth capacitor is connected to the first feedback end of the three-phase motor module control device and the second end of the secondary side of the first transformer and is connected to one end of the third capacitor, the second feedback end and the third feedback end of the three-phase motor module control device through the fourth capacitor, the other end of the third capacitor is connected to the fourth feedback end of the three-phase motor module control device, the fifth end of the first inverter and the second end of the second capacitor, and the sixth end of the first inverter is connected to the IO3 end of the first controller.

[0021] As a further solution of the present invention: the energy storage control module includes a fifth power tube, a full-charge detection device, a fifth resistor, a sixth resistor and an energy storage device;

[0022] Preferably, the drain of the fifth power tube is connected to the first end of the energy storage device and connected to the input end of the full-charge detection device through the fifth resistor, the output end of the full-charge detection device is connected to the gate of the fifth power tube, and the other end of the sixth resistor is connected to the second end of the energy storage device.

[0023] As a further solution of the present invention: the energy storage control module further includes a third resistor, a fourth resistor, a low voltage detection device and a fourth power tube;

[0024] Preferably, the drain of the fourth power tube is connected to the first end of the second capacitor and is connected to one end of the fourth resistor and the input end of the low voltage detection device through the third resistor, the output end of the low voltage detection device is connected to the gate of the fourth power tube and the IO10 end of the first controller, the source of the fourth power tube is connected to the source of the fifth power tube, and the other end of the fourth resistor is connected to the second end of the second capacitor and the second end of the energy storage device.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: when the three-phase motor module is rotating, the auxiliary conversion module performs resonance regulation processing on the electric energy output by the grid-connected and off-grid module in the safe grid-connected and off-grid control circuit of the electric energy feedback device of the present invention, thereby reducing the switching loss of the three-phase motor module; when the three-phase motor module is braking, if the generated regenerative electric energy exceeds the set high-voltage threshold, it will be boosted by the auxiliary conversion module and the AC power grid module will be powered by the grid-connected and off-grid module; when the regenerative electric energy is lower than the high-voltage threshold, the auxiliary conversion module performs high-frequency isolation and transformation processing, and the regenerative electric energy lower than the high-voltage threshold is superimposed by the low-voltage feedback module to meet the grid-connected demand; when the superimposed electric energy is lower than the grid-connected demand, it will be stored by the energy storage control module, thereby improving the utilization rate of electric energy feedback and the safety of grid-connected and off-grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0027] Figure 1 A schematic block diagram of a safe on-grid and off-grid control circuit for an electric energy feedback device provided in an embodiment of the present invention.

[0028] Figure 2 A circuit diagram of a safe off-grid control circuit for an electric energy feedback device provided in an embodiment of the present invention.

[0029] Figure 3 A circuit diagram of an energy storage control module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In one embodiment, see Figure 1 , a safe on-grid and off-grid control circuit of an electric energy feedback device, comprising: an AC power grid module 1, an on-grid and off-grid module 2, an auxiliary conversion module 3, a three-phase motor module 4, an intelligent control module 5, a motor feedback module 6, a low-voltage feedback module 7 and an energy storage control module 8;

[0032] Specifically, the AC power grid module 1 is connected to the on-grid and off-grid module 2, the low-voltage feedback module 7 and the motor feedback module 6, and is used to provide a first AC power, receive a second AC power output by the on-grid and off-grid module 2, a third AC power output by the low-voltage feedback module 7 and a fourth AC power output by the motor feedback module 6;

[0033] The on-grid and off-grid module 2 is connected to the intelligent control module 5 and the auxiliary conversion module 3, and is used to rectify the AC power and output the first DC power, and when receiving the first inversion signal output by the intelligent control module 5, invert the third DC power output by the auxiliary conversion module 3 and output the second AC power;

[0034] The auxiliary conversion module 3 is connected to the intelligent control module 5 and the three-phase motor module 4, and is used for performing resonance adjustment processing on the first DC power and outputting the second DC power when receiving the first pulse signal output by the intelligent control module 5, performing boost processing on the first regenerative electric energy generated by the three-phase motor module 4 and outputting the third DC power when receiving the third pulse signal output by the intelligent control module 5, and performing isolation high-frequency transformation and rectification processing on the first regenerative electric energy and outputting the first feedback electric energy when receiving the second pulse signal and the first rectification signal output by the intelligent control module 5;

[0035] The three-phase motor module 4 is connected to the intelligent control module 5 and is used to invert the second DC electric energy and control the operation of the three-phase motor when receiving the second inversion signal output by the intelligent control module 5, and after stopping receiving the second inversion signal, it will generate the first regenerative electric energy, set the high-voltage threshold and output the first detection signal when the first regenerative electric energy is greater than the high-voltage threshold;

[0036] The intelligent control module 5 is connected to the energy storage control module 8, and is used to output a second inverter signal and output a first pulse signal when outputting the second inverter signal, output the first inverter signal when stopping outputting the second inverter signal, output a third pulse signal when outputting the first inverter signal and receiving the first detection signal, output a second pulse signal and a first rectifier signal when outputting the first inverter signal and not receiving the first detection signal, and output a third inverter signal when outputting the first rectifier signal and receiving the second detection signal output by the energy storage control module 8;

[0037] The motor feedback module 6 is used to receive the first AC power and drive the three-phase motor module to work, provide the second regenerative power when the three-phase motor stops working, perform inversion work and output the fourth AC power when the second regenerative power exceeds the high voltage threshold, and perform voltage conversion and output the second feedback power when the second regenerative power is lower than the high voltage threshold;

[0038] The low-voltage feedback module 7 is connected to the intelligent control module 5, the auxiliary conversion module 3, the energy storage control module 8 and the motor feedback module 6, and is used to receive the electric energy released by the energy storage control module 8, and when receiving the first feedback electric energy and the second feedback electric energy, the first feedback electric energy and the second feedback electric energy are superimposed and output a fourth DC electric energy, and when receiving the third inversion signal, the fourth DC electric energy or the electric energy released by the energy storage control module 8 is inverted and output a third AC electric energy;

[0039] The energy storage control module 8 is used to set a low-voltage threshold and a full-charge threshold, perform voltage sampling on the fourth DC electric energy, and when the sampling signal is less than the low-voltage threshold, output a second detection signal and store the fourth DC electric energy, perform power sampling on the stored electric energy, and when the sampled signal is greater than the full-charge threshold, release the stored electric energy.

[0040] In a specific embodiment, the AC power grid module 1 can adopt an AC power grid circuit composed of an AC power grid to provide AC power and receive AC power; the grid-connected and off-grid module 2 can adopt a grid-connected and off-grid circuit composed of an inductor and a converter to perform three-phase inversion and three-phase rectification processing; the auxiliary conversion module 3 can adopt an auxiliary conversion circuit composed of a field effect tube, an inductor, a thyristor, etc., which can resonate the electric energy input to the three-phase motor module 4, and perform boost regulation processing and isolated high-frequency transformation and rectification processing on the electric energy output by the three-phase motor module 4; the three-phase motor module 4 can adopt a three-phase motor circuit composed of a three-phase motor, a converter, a resistor, etc., which can perform three-phase inversion and rectification processing on the electric energy, drive the three-phase motor to rotate, set a high-voltage threshold and compare the voltage size with the sampled regenerative electric energy; the intelligent control module 5 can adopt an intelligent control circuit composed of a single-chip microcomputer, which integrates many components such as an operator, a controller, a memory, and an input and output device to realize signal processing, data storage, module control, timing control and other functions; the motor feedback module 6 can adopt The motor feedback circuit is composed of a three-phase motor module control device, which can be composed of a bidirectional converter, a field effect tube, a transformer, a thyristor, a diode, a sampling resistor and a three-phase motor module, performs AC-DC operation and drives the three-phase motor module to work. When the three-phase motor module is braked, the generated regenerative electric energy can be processed by DC-AC and connected to the grid. When the regenerative electric energy is lower than the high-voltage threshold, the regenerative electric energy is subjected to high-frequency isolation transformation and rectification, and then transmitted to the low-voltage feedback module 7; the above-mentioned low-voltage feedback module 7 can adopt a low-voltage feedback circuit composed of a boost capacitor, a filter capacitor, a converter, etc. to perform electric energy superposition and three-phase inverter control; the above-mentioned energy storage control module 8 can adopt an energy storage control circuit composed of a low-voltage detection device, a full-charge detection device, a field effect tube, an energy storage device, etc., set a full-charge threshold and a low-voltage threshold, perform voltage sampling on the low-voltage feedback module 7, perform power sampling on the energy storage device, and judge the voltage size of the sampled signal with the low-voltage threshold and the full-charge threshold, respectively, to control the energy storage and discharge work of the energy storage device.

[0041] In another embodiment, see Figure 1 , Figure 2 and Figure 3 , the AC power grid module 1 includes an AC power grid; the on-grid and off-grid module 2 includes a first inductor L1, a second inductor L2, a third inductor L3 and a first converter T1; the intelligent control module 5 includes a first controller U1;

[0042] Specifically, the first end of the AC power grid is connected to the first end of the first converter T1 through the first inductor L1, the second end of the AC power grid is connected to the second end of the first converter T1 through the second inductor L2, the third end of the AC power grid is connected to the third end of the first converter T1 through the third inductor L3, the fourth and fifth ends of the first converter T1 are connected to the auxiliary conversion module 3, and the sixth end of the first converter T1 is connected to the IO1 end of the first controller U1.

[0043] In a specific embodiment, the first converter T1 may be composed of six groups of IGBTs and six groups of diodes, wherein the six groups of IGBTs are used for inverter control and the six groups of diodes are used for rectification control; the first controller U1 may be a STM32 single-chip microcomputer.

[0044] Further, the auxiliary conversion module 3 includes a first power tube Q1, a second power tube Q2, a fourth inductor L4, a first transformer B1, a first diode D1, a third power tube Q3 and a first thyristor S1;

[0045] Specifically, the drain of the first power tube Q1 is connected to the drain of the second power tube Q2 and the fourth end of the first converter T1, the source of the first power tube Q1 is connected to the drain of the third power tube Q3, the cathode of the first diode D1 and the second end of the primary side of the first transformer B1, and is connected to the source of the second power tube Q2, the first end of the primary side of the first transformer B1 and the three-phase motor module 4 through the fourth inductor L4, the anode of the first diode D1 is connected to the source of the third power tube Q3 and the fifth end of the first converter T1, the first end of the secondary side of the first transformer B1 is connected to the anode of the first thyristor S1, the second end of the secondary side of the first converter T1 and the cathode of the first thyristor S1 are connected to the low-voltage feedback module 7, and the gate of the first power tube Q1, the gate of the second power tube Q2, the gate of the third power tube Q3 and the control end of the first thyristor S1 are respectively connected to the IO4 end, the IO6 end, the IO7 end and the IO8 end of the first controller U1.

[0046] In a specific embodiment, the first power tube Q1, the second power tube Q2 and the third power tube Q3 can all be N-channel field effect tubes, wherein the second power tube Q2 cooperates with the first power tube Q1, the fourth inductor L4 and the first diode D1 to perform resonance adjustment processing, the first power tube Q1 cooperates with the first diode D1 and the fourth inductor L4 to perform boost processing, and the third power tube Q3 cooperates with the first transformer B1 to perform high-frequency isolation transformation processing; the first transformer B1 can be a high-frequency transformer; the first thyristor S1 can be a unidirectional thyristor.

[0047] Further, the three-phase motor module 4 includes a first capacitor C1, a first resistor R1, a second resistor R2, a high voltage detection device, a second converter T2 and a three-phase motor;

[0048] Specifically, one end of the first capacitor C1 is connected to the source of the second power tube Q2 and the first end of the first converter T1 and is connected to the input end of the high-voltage detection device and one end of the second resistor R2 through the first resistor R1. The other end of the first capacitor C1 is connected to the other end of the second resistor R2, the second end of the second converter T2 and the fifth end of the first converter T1. The third end, the fourth end and the fifth end of the second converter T2 are respectively connected to the first end, the second end and the third end of the three-phase motor. The output end of the high-voltage detection device and the sixth end of the second converter T2 are respectively connected to the IO9 end and the IO2 end of the first controller U1.

[0049] In a specific embodiment, the high-voltage detection device may be composed of a reference power supply and a comparator, and the reference power supply provides a high-voltage threshold. A voltage greater than the high-voltage threshold may supply power to the AC power grid module 1 through the grid-connected module 2; the selection of the second converter T2 is the same as that of the first converter T1;

[0050] Further, the low voltage feedback module 7 includes a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, a first inverter T3, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5; the motor feedback module 6 includes a three-phase motor module control device;

[0051] Specifically, the first end of the first inverter T3 is connected to the first end of the AC power grid and the first power supply end of the three-phase motor module control device through the fifth inductor L5, the second end of the first inverter T3 is connected to the second end of the AC power grid and the second power supply end of the three-phase motor module control device through the sixth inductor L6, the third end of the first inverter T3 is connected to the third end of the AC power grid and the third power supply end of the three-phase motor module control device through the seventh inductor L7, the fourth end of the first inverter T3 is connected to the first end of the second capacitor C2, one end of the fifth capacitor C5, the cathode of the first thyristor S1 and the energy storage control module 8, the other end of the fifth capacitor C5 is connected to the first feedback end of the three-phase motor module control device and the second end of the secondary side of the first transformer B1 and is connected to one end of the third capacitor C3, the second feedback end and the third feedback end of the three-phase motor module control device through the fourth capacitor C4, the other end of the third capacitor C3 is connected to the fourth feedback end of the three-phase motor module control device, the fifth end of the first inverter T3 and the second end of the second capacitor C2, and the sixth end of the first inverter T3 is connected to the IO3 end of the first controller U1.

[0052] In a specific embodiment, the first inverter T3 may be composed of six groups of IGBTs; the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 are connected in series; the three-phase motor module control device may be composed of a bidirectional converter, a field effect transistor, a transformer, a thyristor, a diode, a sampling resistor and a three-phase motor module. The three-phase motor module is composed of multiple groups of three-phase motors, performs AC-DC operation and drives the three-phase motor module to work. When the three-phase motor module is braked, the generated regenerative electric energy can be processed by DC-AC and connected to the grid. When the regenerative electric energy is lower than the high-voltage threshold, the regenerative electric energy is subjected to high-frequency isolation transformation and rectification, and then transmitted to the low-voltage feedback module 7.

[0053] Further, the energy storage control module 8 includes a fifth power tube Q5, a full-charge detection device, a fifth resistor R5, a sixth resistor R6 and an energy storage device;

[0054] Specifically, the drain of the fifth power tube Q5 is connected to the first end of the energy storage device and connected to the input end of the full charge detection device through the fifth resistor R5. The output end of the full charge detection device is connected to the gate of the fifth power tube Q5. The other end of the sixth resistor R6 is connected to the second end of the energy storage device.

[0055] In a specific embodiment, the full-charge detection device may be composed of a reference power supply and a comparator, and the reference power supply provides a full-charge threshold; the fifth power tube Q5 may be an N-channel field effect tube.

[0056] Furthermore, the energy storage control module 8 also includes a third resistor R3, a fourth resistor R4, a low voltage detection device and a fourth power tube Q4;

[0057] Specifically, the drain of the fourth power tube Q4 is connected to the first end of the second capacitor C2 and connected to one end of the fourth resistor R4 and the input end of the low voltage detection device through the third resistor R3, the output end of the low voltage detection device is connected to the gate of the fourth power tube Q4 and the IO10 end of the first controller U1, the source of the fourth power tube Q4 is connected to the source of the fifth power tube Q5, and the other end of the fourth resistor R4 is connected to the second end of the second capacitor C2 and the second end of the energy storage device.

[0058] In a specific embodiment, the low voltage detection device may be composed of a reference power supply and a comparator, and the reference power supply provides a low voltage threshold; the fourth power tube Q4 may be an N-channel field effect tube.

[0059] In a safe off-grid control circuit of an electric energy feedback device of the present embodiment, an AC power grid provides AC power, a first converter T1 performs rectification processing, and when a second inverter signal is output at the IO2 end of the first controller U1 and the second converter T2 is controlled to perform an inverter operation, the IO6 end of the first controller U1 controls the conduction of the second power tube Q2 to control the transmission of electric energy, and the IO4 end of the first controller U1 controls the conduction of the first power tube Q1 to resonate with the fourth inductor L4 and the first diode D1, so that when the second converter T2 performs an inverter operation, the input voltage forms a short-term zero state, and then the IGBT switch used by the second converter T2 is in a zero-voltage soft switching state, thereby reducing the switching voltage of the second converter T2. The inverted electric energy drives the three-phase motor to rotate. When the IO2 end of the first controller U1 stops controlling the inversion of the second converter T2, the three-phase motor brakes and generates the first regenerative electric energy, which is rectified by the second converter T2 and then output. At the same time, the first resistor R1 and the second resistor R2 perform voltage sampling on the first regenerative electric energy. When the sampled signal is greater than the high-voltage threshold value set by the high-voltage detection device, the IO7 end of the first controller U1 outputs the third pulse signal to control the third power tube Q3 to turn on, and cooperates with the fourth power tube Q4 and the first power tube Q1 to perform voltage boost processing. Then, the IO1 end of the first controller U1 outputs the first inversion signal to invert the boosted electric energy so as to be incorporated into the AC power grid. When the first resistor R 1 and the signal sampled by the second resistor R2 is lower than the high-voltage threshold, the IO1 end of the first controller U1 stops outputting the first inverter signal, the IO7 end of the first controller U1 outputs the second pulse signal to control the conduction state of the third power tube Q3, so that the first transformer B1 performs high-frequency isolation transformation processing, the IO8 end of the first controller U1 outputs the first rectifier signal to control the first thyristor S1 to perform rectification, outputs the first feedback electric energy and is stored by the fifth capacitor C5, similarly, the three-phase motor module control device drives multiple groups of three-phase motors and directly incorporates the AC electric energy when the regenerative electric energy generated by the braking three-phase motor is greater than the high-voltage threshold, and when the regenerative electric energy is less than the high-voltage threshold, it is stored through the third capacitor C3 or the fourth capacitor C4. The third resistor R3 and the fourth resistor R4 perform voltage sampling on the superimposed electric energy of the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5. If the sampled signal is less than the low voltage threshold set by the low voltage detection device, the fourth power tube Q4 is controlled to be turned on, and the superimposed electric energy is stored by the energy storage device. The fifth resistor R5 and the sixth resistor R6 perform electrical quantity sampling on the energy storage device. When the sampled signal is greater than the full power threshold set by the full power detection device, the fifth power tube Q5 is turned on, and the energy storage device is discharged. If the superimposed signal is greater than the low voltage threshold or the energy storage device is discharged, the IO3 terminal of the first controller U1 outputs a third inversion signal and controls the first inverter T3 to perform inversion, and the inverted electric energy is incorporated into the AC power grid.

[0060] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0061] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A safe on-grid and off-grid control circuit for an electric energy feedback device, characterized in that: The safe on-grid and off-grid control circuit of the electric energy feedback device comprises: an AC power grid module, an on-grid and off-grid module, an auxiliary conversion module, a three-phase motor module, an intelligent control module, a motor feedback module, a low-voltage feedback module and an energy storage control module; The AC power grid module is connected to the on-grid and off-grid module, the low-voltage feedback module and the motor feedback module, and is used to provide a first AC power, receive a second AC power output by the on-grid and off-grid module, a third AC power output by the low-voltage feedback module and a fourth AC power output by the motor feedback module; The grid-connected and off-grid module is connected to the intelligent control module and the auxiliary conversion module, and is used to rectify the AC power and output the first DC power, and when receiving the first inversion signal output by the intelligent control module, invert the third DC power output by the auxiliary conversion module and output the second AC power; The auxiliary conversion module is connected to the intelligent control module and the three-phase motor module, and is used to perform resonance adjustment processing on the first DC power and output the second DC power when receiving the first pulse signal output by the intelligent control module, to boost the first regenerative power generated by the three-phase motor module and output the third DC power when receiving the third pulse signal output by the intelligent control module, and to perform isolation high-frequency transformation and rectification processing on the first regenerative power and output the first feedback power when receiving the second pulse signal and the first rectification signal output by the intelligent control module; The three-phase motor module is connected to the intelligent control module and is used to invert the second DC electric energy and control the operation of the three-phase motor when receiving the second inversion signal output by the intelligent control module, and after stopping receiving the second inversion signal, it will generate the first regenerative electric energy, set the high-voltage threshold and output the first detection signal when the first regenerative electric energy is greater than the high-voltage threshold; The intelligent control module is connected to the energy storage control module, and is used to output a second inverter signal and output a first pulse signal when outputting the second inverter signal, output the first inverter signal when stopping outputting the second inverter signal, output a third pulse signal when outputting the first inverter signal and receiving the first detection signal, output a second pulse signal and a first rectifier signal when outputting the first inverter signal and not receiving the first detection signal, and output a third inverter signal when outputting the first rectifier signal and receiving the second detection signal output by the energy storage control module; The motor feedback module is used to receive the first AC power and drive the three-phase motor module to work, provide the second regenerative power when the three-phase motor stops working, perform inversion work and output the fourth AC power when the second regenerative power exceeds the high voltage threshold, and perform voltage conversion and output the second feedback power when the second regenerative power is lower than the high voltage threshold; The low-voltage feedback module is connected to the intelligent control module, the auxiliary conversion module, the energy storage control module and the motor feedback module, and is used to receive the electric energy released by the energy storage control module, and when receiving the first feedback electric energy and the second feedback electric energy, the first feedback electric energy and the second feedback electric energy are superimposed and output a fourth direct current electric energy, and when receiving the third inversion signal, the fourth direct current electric energy or the electric energy released by the energy storage control module is inverted and output a third alternating current electric energy; The energy storage control module is used to set a low voltage threshold and a full power threshold, perform voltage sampling on the fourth DC electric energy and, when the sampling signal is less than the low voltage threshold, output a second detection signal and store the fourth DC electric energy, perform power sampling on the stored electric energy and, when the sampled signal is greater than the full power threshold, release the stored electric energy.

2. A safe on-grid and off-grid control circuit for an electric energy feedback device according to claim 1, characterized in that: The AC power grid module includes an AC power grid; the on-grid and off-grid module includes a first inductor, a second inductor, a third inductor and a first converter; the intelligent control module includes a first controller; The first end of the AC power grid is connected to the first end of the first converter through a first inductor, the second end of the AC power grid is connected to the second end of the first converter through a second inductor, the third end of the AC power grid is connected to the third end of the first converter through a third inductor, the fourth and fifth ends of the first converter are connected to the auxiliary conversion module, and the sixth end of the first converter is connected to the IO1 end of the first controller.

3. A safe on-grid and off-grid control circuit for an electric energy feedback device according to claim 2, characterized in that: The auxiliary conversion module includes a first power tube, a second power tube, a fourth inductor, a first transformer, a first diode, a third power tube and a first thyristor; The drain of the first power tube is connected to the drain of the second power tube and the fourth end of the first converter, the source of the first power tube is connected to the drain of the third power tube, the cathode of the first diode and the second end of the primary side of the first transformer, and is connected to the source of the second power tube, the first end of the primary side of the first transformer and the three-phase motor module through the fourth inductor, the anode of the first diode is connected to the source of the third power tube and the fifth end of the first converter, the first end of the secondary side of the first transformer is connected to the anode of the first thyristor, the second end of the secondary side of the first converter and the cathode of the first thyristor are connected to the low-voltage feedback module, and the gate of the first power tube, the gate of the second power tube, the gate of the third power tube and the control end of the first thyristor are respectively connected to the IO4 end, the IO6 end, the IO7 end and the IO8 end of the first controller.

4. The safe on-grid and off-grid control circuit of an electric energy feedback device according to claim 3, characterized in that: The three-phase motor module includes a first capacitor, a first resistor, a second resistor, a high-voltage detection device, a second converter and a three-phase motor; One end of the first capacitor is connected to the source of the second power tube and the first end of the first converter and is connected to the input end of the high-voltage detection device and one end of the second resistor through the first resistor. The other end of the first capacitor is connected to the other end of the second resistor, the second end of the second converter and the fifth end of the first converter. The third end, the fourth end and the fifth end of the second converter are respectively connected to the first end, the second end and the third end of the three-phase motor. The output end of the high-voltage detection device and the sixth end of the second converter are respectively connected to the IO9 end and the IO2 end of the first controller.

5. The safe on-grid and off-grid control circuit of an electric energy feedback device according to claim 4, characterized in that: The low-voltage feedback module includes a fifth inductor, a sixth inductor, a seventh inductor, a first inverter, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor; the motor feedback module includes a three-phase motor module control device; The first end of the first inverter is connected to the first end of the AC grid and the first power supply end of the three-phase motor module control device through a fifth inductor, the second end of the first inverter is connected to the second end of the AC grid and the second power supply end of the three-phase motor module control device through a sixth inductor, the third end of the first inverter is connected to the third end of the AC grid and the third power supply end of the three-phase motor module control device through a seventh inductor, the fourth end of the first inverter is connected to the first end of the second capacitor, one end of the fifth capacitor, the cathode of the first thyristor and the energy storage control module, the other end of the fifth capacitor is connected to the first feedback end of the three-phase motor module control device and the second end of the secondary side of the first transformer and is connected to one end of the third capacitor, the second feedback end and the third feedback end of the three-phase motor module control device through the fourth capacitor, the other end of the third capacitor is connected to the fourth feedback end of the three-phase motor module control device, the fifth end of the first inverter and the second end of the second capacitor, and the sixth end of the first inverter is connected to the IO3 end of the first controller.

6. A safe on-grid and off-grid control circuit for an electric energy feedback device according to claim 5, characterized in that: The energy storage control module includes a fifth power tube, a full-charge detection device, a fifth resistor, a sixth resistor and an energy storage device; The drain of the fifth power tube is connected to the first end of the energy storage device and is connected to the input end of the full-charge detection device through the fifth resistor. The output end of the full-charge detection device is connected to the gate of the fifth power tube. The other end of the sixth resistor is connected to the second end of the energy storage device.

7. A safe on-grid and off-grid control circuit for an electric energy feedback device according to claim 6, characterized in that: The energy storage control module also includes a third resistor, a fourth resistor, a low voltage detection device and a fourth power tube; The drain of the fourth power tube is connected to the first end of the second capacitor and connected to one end of the fourth resistor and the input end of the low voltage detection device through the third resistor, the output end of the low voltage detection device is connected to the gate of the fourth power tube and the IO10 end of the first controller, the source of the fourth power tube is connected to the source of the fifth power tube, and the other end of the fourth resistor is connected to the second end of the second capacitor and the second end of the energy storage device.

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