A new energy multi-mode electric vehicle charging pile

Abstract

The present invention provides a new energy multi-mode electric vehicle charging pile, comprising: a photovoltaic unit, a main circuit, a control circuit, a voltage comparison unit, a topology selection circuit and an energy storage module; the main circuit is used to convert the output of the photovoltaic unit into a controllable output under the control of the control circuit so as to supply power to a load; the main circuit is provided with at least two conversion topologies with different voltage gain ranges; the voltage comparison unit and the topology selection circuit obtain the output after conversion by the main circuit, compare the current output value with a reference value, and select a conversion topology with a corresponding voltage gain range according to the magnitude relationship between the two; the energy storage module is connected to the photovoltaic unit through the main circuit; the energy storage module is used to store the surplus electric energy of the photovoltaic unit and directly supply power to the load under set working conditions. The charging pile of the present invention has three working topologies, has a wide voltage range, selects different topological structures to meet the load requirements under the conditions of load and input changes, and has strong adaptability.

Description

Technical Field

[0001] The present invention belongs to the technical field of charging piles, and particularly relates to a new energy multi-mode electric vehicle charging pile. Background Art

[0002] The topology of traditional power electronic converters is fixed, and the voltage gain is limited by the form of the topology. The voltage gain can be changed by adjusting parameters such as duty cycle, and it is applied to electric vehicle charging piles.

[0003] However, the existing traditional power electronic converters still have the following problems: (1) The voltage gain of the converter is limited by the topology and it is difficult to meet the occasions that require high gain; (2) The flexibility of the circuit is relatively low and it is difficult to meet the requirements under complex working conditions. Summary of the Invention

[0004] In view of this, the present invention aims to provide a new energy multi-mode electric vehicle charging pile, which can flexibly adjust the converter topology according to different working conditions, thereby changing the voltage gain and making the circuit have high flexibility.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A new energy multi-mode electric vehicle charging pile, comprising: photovoltaic, main circuit, control circuit, voltage comparison unit, topology selection circuit and energy storage module;

[0007] The main circuit is used to convert the output of the photovoltaic into a controllable output under the control of the control circuit so as to supply power to the load;

[0008] The main circuit is provided with at least two conversion topologies with different voltage gain ranges;

[0009] The voltage comparison unit and the topology selection circuit obtain the output after the main circuit conversion, compare the current output value with the reference value, and select the conversion topology corresponding to the voltage gain range according to the magnitude relationship between the two;

[0010] The energy storage module is connected to the photovoltaic through the main circuit;

[0011] The energy storage module is used to store the excess electric energy of the photovoltaic and directly supply power to the load under set working conditions.

[0012] Further, the voltage comparison unit and the topology selection circuit include: a group of relays and a comparator;

[0013] The comparator is used to compare the output after the transformation of the main circuit with the first reference value and the second reference value. If it is less than the first reference value, a switching first topology signal is generated; if it is between the first reference value and the second reference value, a switching second topology signal is generated; if it is greater than the second reference value, a switching third topology signal is generated. The second reference value is greater than the first reference value.

[0014] A group of relays is connected to the main circuit and is used to switch the transformed topology of the main circuit to the first transformed topology according to the switching first topology signal, or to switch the transformed topology of the main circuit to the second transformed topology according to the switching second topology signal, or to switch the transformed topology of the main circuit to the third transformed topology according to the switching third topology signal.

[0015] Furthermore, the first transformed topology includes: a first branch, a second branch, a main capacitor, and a switching tube;

[0016] The first branch includes a first inductor. One end of the first inductor serves as one end of the first branch and is connected to the photovoltaic terminal, and the other end serves as the other end of the first branch and is respectively connected to the negative electrode of the switching tube and one end of the second branch;

[0017] The second branch includes a fifth diode. The anode of the fifth diode serves as one end of the second branch and is connected between the first branch and the switching tube, and the cathode serves as the other end of the second branch and is connected to one end of the main capacitor and the load terminal;

[0018] The other end of the main capacitor is respectively connected to the photovoltaic terminal, the positive electrode of the switching tube, and the load terminal;

[0019] The positive electrode of the switching tube is connected to the photovoltaic terminal.

[0020] Furthermore, the voltage gain of the first transformed topology is specifically:

[0021]

[0022] Wherein, G1 is the voltage gain of the first transformed topology, and d is the duty cycle of the control circuit for controlling the switching tube.

[0023] Furthermore, the second transformed topology includes: a first branch, a third branch, a switching tube, and a main capacitor;

[0024] The third branch includes a second capacitor, a third capacitor, a sixth diode, and a seventh diode. One end of the second capacitor and the cathode of the seventh diode are connected and then serve as the first end of the third branch and are connected between the first branch and the negative electrode of the switching tube. The other end of the second capacitor and the cathode of the sixth diode are connected and then serve as the second end of the third branch and are connected to one end of the main capacitor and the load terminal;

[0025] One end of the third capacitor is connected to the anode of the sixth diode and then serves as the third end of the third branch, which is connected between the positive electrode of the switching tube and the photovoltaic terminal. The other end of the third capacitor is connected to the anode of the seventh diode and then serves as the fourth end of the third branch, which is connected to the other end of the main capacitor and the load terminal.

[0026] Further, the voltage gain of the second conversion topology is specifically:

[0027]

[0028] Among them, G2 is the voltage gain of the first conversion topology, and d is the duty cycle of the control circuit for controlling the switching tube.

[0029] Further, the third topology includes: a fourth branch, a second branch, a switching tube, and a main capacitor;

[0030] The fourth branch includes a first diode, a second diode, a third diode, a fourth diode, a second inductor, a third inductor, and a first capacitor;

[0031] One end of the anode of the first diode, the anode of the second diode, and the third inductor are connected and then serve as one end of the fourth branch to be connected to the photovoltaic terminal. The cathode of the second diode and one end of the first capacitor are connected and then connected to the anode of the third diode. The cathode of the first diode and the cathode of the third diode are connected and then connected to one end of the second inductor. The other end of the third inductor and the other end of the first capacitor are connected and then connected to the anode of the fourth diode. The cathode of the fourth diode and the other end of the second inductor are connected and then serve as the other end of the fourth branch to be respectively connected to the negative electrode of the switching tube and one end of the second branch.

[0032] Further, the voltage gain of the third conversion topology is specifically:

[0033]

[0034] Among them, G3 is the voltage gain of the first conversion topology, and d is the duty cycle of the control circuit for controlling the switching tube.

[0035] Further, the number of relays is 3. Among them, the first branch and the fourth branch are respectively connected to the main circuit through two static contacts of the first relay. The second branch is connected to the main circuit through one static contact of the second relay and one static contact of the third relay. The third branch is connected to the main circuit through the other static contact of the second relay and the other static contact of the third relay.

[0036] Further, the comparator includes a first comparator and a second comparator. The process of the voltage comparison unit and the topology selection circuit for selecting the conversion topology corresponding to the voltage gain range specifically includes:

[0037] When the outputs after transformation of the main circuit compared by the first comparator and the second comparator are less than the corresponding reference values, three low-level signals are output. The low-level signal output by the first comparator passes through a NOT gate to obtain a high-level signal, which serves as the control signal for the first relay to control the first branch to be connected to the main circuit. For the two low-level signals output by the second comparator, one low-level signal directly serves as the control signal for the third relay to control one end of the second branch to be connected to the main circuit, and the other low-level signal passes through a NOT gate to obtain a high-level signal, which serves as the control signal for the second relay to control the other end of the second branch to be connected to the main circuit, so that the main circuit is switched to the first topology;

[0038] When the outputs after transformation of the main circuit compared by the first comparator and the second comparator are between the first reference value and the second reference value, one low-level signal and two high-level signals are output. The two high-level signals output by the first comparator serve as the control signals for the first relay and the third relay, respectively controlling the first branch to be connected to the main circuit and controlling the third end of the third branch to be connected to the main circuit. The high-level signal of the second comparator passes through a NOT gate to obtain a low-level signal, which serves as the control signal for the second relay to control the first end of the third branch to be connected to the main circuit, so that the main circuit is switched to the second transformation topology;

[0039] When the outputs after transformation of the main circuit compared by the first comparator and the second comparator are both greater than the second reference value, three high-level signals are output. The two high-level signals output by the first comparator pass through NOT gates to obtain two low-level signals, which serve as the control signals for the first relay and the third relay, controlling the first branch to be connected to the main circuit and controlling one end of the second branch to be connected to the circuit. The high-level signal of the second comparator directly serves as the control signal for the second relay to control the other end of the second branch to be connected to the main circuit, so that the main circuit is switched to the third transformation topology.

[0040] In summary, the present invention provides a new energy multi-mode electric vehicle charging pile, including: photovoltaic, main circuit, control circuit, voltage comparison unit, topology selection circuit and energy storage module; the main circuit is used to transform the output of the photovoltaic into a controllable output under the control of the control circuit for power supply to the load; the main circuit is provided with no less than two transformation topologies with different voltage gain ranges; the voltage comparison unit and the topology selection circuit obtain the output after transformation of the main circuit, compare the current output value with the reference value, and select the transformation topology with the corresponding voltage gain range according to the size relationship between the two; the energy storage module is connected to the photovoltaic through the main circuit; the energy storage module is used to store the excess electric energy of the photovoltaic and directly supply power to the load under the set working conditions. The charging pile of the present invention has three working topologies, has a wide voltage range, and can select different topological structures to meet the load requirements under the conditions of load and input changes, and has strong adaptability. Description of the Drawings

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 It is the topological structure diagram of the new energy multi-mode electric vehicle charging pile provided by the embodiment of the present invention;

[0043] Figure 2 It is the topological structure diagram of the first transformation topology accessing the main circuit provided by the embodiment of the present invention;

[0044] Figure 3 It is the topological structure diagram of the second transformation topology accessing the main circuit provided by the embodiment of the present invention;

[0045] Figure 4 It is the topological structure diagram of the third transformation topology accessing the main circuit provided by the embodiment of the present invention;

[0046] Figure 5 It is the charging mode diagram when there is no electric vehicle provided by the embodiment of the present invention;

[0047] Figure 6 It is the schematic diagram of the power supply mode of the energy storage module of the new energy multi-mode electric vehicle charging pile provided by the embodiment of the present invention. Specific embodiments

[0048] To make the purpose, features, and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0049] The embodiment of the present invention provides a new energy multi-mode electric vehicle charging pile, including: photovoltaic, main circuit, control circuit, voltage comparison unit, topology selection circuit, and energy storage module; the main circuit is used to transform the output of the photovoltaic into a controllable output under the control of the control circuit to supply power to the load; the main circuit is provided with no less than two transformation topologies with different voltage gain ranges; the voltage comparison unit and the topology selection circuit obtain the output after the transformation of the main circuit, compare the current output value with the reference value, and select the transformation topology corresponding to the voltage gain range according to the size relationship between the two; the energy storage module is connected to the photovoltaic through the main circuit; the energy storage module is used to store the excess electric energy of the photovoltaic and directly supply power to the load under the set working conditions.

[0050] In one embodiment of the present invention, the voltage comparison unit and the topology selection circuit include: a group of relays and a comparator;

[0051] The comparator is used to compare the output after the transformation of the main circuit with a first reference value and a second reference value. If it is less than the first reference value, a first topology switching signal is generated. If it is between the first reference value and the second reference value, a second topology switching signal is generated. If it is greater than the second reference value, a third topology switching signal is generated. The second reference value is greater than the first reference value;

[0052] A group of relays is connected to the main circuit and is used to switch the transformation topology of the main circuit to a first transformation topology according to the first topology switching signal, or to switch the transformation topology of the main circuit to a second transformation topology according to the second topology switching signal, or to switch the transformation topology of the main circuit to a third transformation topology according to the third topology switching signal.

[0053] The following further embodiments will introduce in detail the first transformation topology, the second transformation topology, the third transformation topology and their switching.

[0054] In a further embodiment of the present invention, the first transformation topology may include a first branch, a second branch, a main capacitor C0 and a switching tube S.

[0055] The first branch includes a first inductor L1. One end of the first inductor L1 is used as one end of the first branch and is connected to the photovoltaic terminal, and the other end is used as the other end of the first branch and is respectively connected to the negative electrode of the switching tube S and one end of the second branch;

[0056] The second branch includes a fifth diode D5. The anode of the fifth diode D5 is used as one end of the second branch and is connected between the first branch and the switching tube S, and the cathode is used as the other end of the second branch and is connected to one end of the main capacitor C0 and the load terminal;

[0057] The other end of the main capacitor C0 is respectively connected to the photovoltaic terminal, the positive electrode of the switching tube S and the load terminal;

[0058] The positive electrode of the switching tube S is connected to the photovoltaic terminal.

[0059] Figure 1 It is a topological structure diagram of a new energy multi-mode electric vehicle charging pile. Among them, the load terminal includes an electric vehicle. The present invention aims to provide a charging pile with a wide voltage regulation range, mainly realized by several transformation topologies set in the main circuit. Therefore, the circuit design of the photovoltaic terminal and the load terminal refers to the prior art and will not be elaborated here.

[0060] Figure 2 It is a topological structure diagram of the first transformation topology connected to the main circuit. According to its structure, the voltage gain of topology 1 is:

[0061]

[0062] Among them, G1 is the voltage gain of the first conversion topology, and d is the duty cycle for the control circuit to control the switching transistor.

[0063] When the load or input changes, such as the addition of an electric vehicle and the uncertainty of new energy photovoltaic, the output voltage V o may not meet the load demand. Therefore, a variable structure is required to meet the load demand. The main circuit's real-time output voltage V o value and the reference voltage V ref2 are compared by a comparator to generate a switching topology signal. Among them, for topology 1, when V o < V ref2 < V ref3 the comparator generates a switching first topology signal, and a group of relays are made to control the first conversion topology to be connected to the main circuit.

[0064] In a further embodiment of the present invention, the second conversion topology includes a first branch, a third branch, a switching transistor S, and a main capacitor C0;

[0065] The third branch includes a second capacitor C2, a third capacitor C3, a sixth diode D6, and a seventh diode D7. One end of the second capacitor C2 and the cathode of the seventh diode D7 are connected and used as the first end of the third branch, which is connected between the first branch and the negative pole of the switching transistor S. The other end of the second capacitor C2 is connected to the cathode of the sixth diode D6 and used as the second end of the third branch, which is connected to one end of the main capacitor C0 and the load end;

[0066] One end of the third capacitor C3 is connected to the anode of the sixth diode D6 and used as the third end of the third branch, which is connected between the positive pole of the switching transistor S and the photovoltaic end. The other end of the third capacitor C3 is connected to the anode of the seventh diode D7 and used as the fourth end of the third branch, which is connected to the other end of the main capacitor C0 and the load end.

[0067] Figure 3 is the topological structure diagram of the second conversion topology connected to the main circuit. According to its structure, the voltage gain of topology 2 is obtained as:

[0068]

[0069] Among them, G2 is the voltage gain of the first conversion topology, and d is the duty cycle for the control circuit to control the switching transistor.

[0070] When the main circuit's real-time output voltage V o value and the reference voltages V ref2 and V ref3 are compared by a comparator to generate a switching topology signal. For topology 2, when V oWhen it is between V ref2 and V ref3 a comparator generates a switching second topology signal to make a group of relays control the second conversion topology to be connected to the main circuit.

[0071] In a further embodiment of the present invention, the third topology includes: a fourth branch, a second branch, a switching tube S, and a main capacitor C0;

[0072] The fourth branch includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a second inductor L2, a third inductor L3, and a first capacitor C1;

[0073] The anodes of the first diode D1, the second diode D2, and one end of the third inductor L3 are connected together and used as one end of the fourth branch to be connected to the photovoltaic terminal. The cathode of the second diode D2 and one end of the first capacitor C1 are connected together and then connected to the anode of the third diode D3. The cathode of the first diode D1 and the cathode of the third diode D3 are connected together and then connected to one end of the second inductor L2. The other end of the third inductor L3 and the other end of the first capacitor C1 are connected together and then connected to the anode of the fourth diode D4. The cathode of the fourth diode D4 and the other end of the second inductor L2 are connected together and used as the other end of the fourth branch to be respectively connected to the negative electrode of the switching tube S and one end of the second branch.

[0074] Figure 4 is the topology structure diagram of the third conversion topology connected to the main circuit. According to its structure, the voltage gain of topology 3 is obtained as:

[0075]

[0076] wherein, G3 is the voltage gain of the first conversion topology, and d is the duty cycle of the control circuit for controlling the switching tube.

[0077] When the real-time output voltage V of the main circuit o value and the reference voltage V ref2 and V ref3 are compared by a comparator to generate a switching topology signal. For topology 2, when V ref2 < V ref3 < Vo, a comparator generates a switching third topology signal to make a group of relays control the third conversion topology to be connected to the main circuit.

[0078] In order to achieve stable switching control, in a further embodiment of the present invention, the number of relays is set to three. Among them, the first branch and the fourth branch are respectively connected to the main circuit through two static contacts of the first relay K1, the second branch is connected to the main circuit through one static contact of the second relay K2 and one static contact of the third relay K3, and the third branch is connected to the main circuit through the other static contact of the second relay K2 and the other static contact of the third relay K3.

[0079] Based on the above design, the comparator compares to generate signals for relays K1-K3, and the voltage comparison unit and the topology selection circuit perform topology selection according to the relay signals, which are divided into the following three states:

[0080] Furthermore, the comparator includes a first comparator and a second comparator. The process of the voltage comparison unit and the topology selection circuit selecting a conversion topology corresponding to a voltage gain range specifically includes:

[0081] (A) Topology 1: Vo < Vref2 < Vref3, the high-level signal 1 is connected to relays K1 and K2, and the low-level signal 0 is connected to relay K3;

[0082] (B) Topology 2: Vref2 < Vo < Vref3, the high-level signal 1 is connected to relays K1 and K3, and the low-level signal 0 is connected to relay K2;

[0083] (C) Topology 3: Vref2 < Vref3 < Vo, the high-level signal 1 is connected to relay K2, and the low-level signal 0 is connected to relays K1 and K3.

[0084] For state A, when V o < V ref2 < V ref3 At this time, where V ref2 And V ref3 The specific values of should be set according to the actual working conditions. The real-time output voltage V of the main circuit o And the reference voltages V ref2 And V ref3 Are compared through the comparator, and two low-level signals 00 are output. a1 and a2 pass through NOT gates to obtain two high-level signals 11, which are connected to relay K1 and relay K2. At this time, relays K1 and relay K2 act. K1 is connected to the inductor L1 branch, K2 is connected to the diode D5 branch, a3 obtains a low-level signal 0 and is connected to relay K3. The new energy electric vehicle charging pile selects topology 1, as Figure 2 Shown, the voltage gain at this time is The new energy input charges the energy storage module through topology 1 and supplies power to the electric vehicle. The drive circuit generates a duty cycle signal to drive the switching tube through the voltage error signal processing and PWM link of the main control circuit, increasing the working stability of the circuit.

[0085] For state B, when V ref2 < V o < V ref3 When, where V ref2 and V ref3 The specific values of should be set according to the actual working conditions. The real-time output voltage V of the main circuit o and the reference voltage V ref2 and V ref3 are compared by a comparator, and two levels 10, a1 and a3 obtain a high-level signal 1, which is connected to relay K1 and relay K3. At this time, relays K1 and K3 act. K1 is connected to the inductor L1 branch, and K3 is connected to the diode D6 and capacitor C3 branches. a2 obtains a low-level signal 0. At this time, relay K2 acts, and K2 is connected to the capacitor C2 and diode D7 branches. The new energy electric vehicle charger selects topology 2, as Figure 3 shown. The voltage gain at this time is The new energy input charges the energy storage module through topology 2 and supplies power to the electric vehicle. The drive circuit generates a duty cycle signal to drive the switching tube through the voltage error signal processing and PWM link of the main control circuit, increasing the working stability of the circuit.

[0086] For state C, when V ref2 < V ref3 < V o When, where V ref2 and V ref3 The specific values of should be set according to the actual working conditions. The real-time output voltage V of the main circuit o and the reference voltage V ref2 and V ref3 are compared by a comparator, and two levels 11, a1 and a3 obtain a low-level signal 0 through a NOT gate and are connected to relay K1 and relay K3. At this time, relays K1 and K3 act. K1 is connected to the inductor L3, diode D1 and diode D2 branches. a2 obtains a high-level signal 1. At this time, relay K2 acts, and K2 is connected to the diode D5 branch. The new energy electric vehicle charger selects topology 3, as Figure 4 shown. The voltage gain at this time is The new energy input charges the energy storage module through topology 3 and supplies power to the electric vehicle. The drive circuit generates a duty cycle signal to drive the switching tube through the voltage error signal processing and PWM link of the main control circuit, increasing the working stability of the circuit.

[0087] In addition, the variable-structure photovoltaic electric vehicle charger is also provided with an energy storage module. As Figure 5 shown, the new energy photovoltaic charges the energy storage module through the main circuit. As Figure 6As shown, new energy has problems such as uncertainty and randomness. Especially under complex working conditions such as bad weather, at night, and circuit failures, the energy storage module supplies power to the electric vehicle to ensure the normal operation of the circuit.

[0088] The variable-structure photovoltaic electric vehicle charging pile provided by the present invention has two working topologies, has a wide voltage range, and selects different topologies to meet the load requirements under the conditions of load and input changes, with strong adaptability. In addition, under complex working conditions such as circuit failures, the energy storage module ensures the normal operation of the circuit, with high reliability.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A new energy multi-mode electric vehicle charging pile, characterized in that, Comprising: Photovoltaic, main circuit, control circuit, voltage comparison unit, topology selection circuit and energy storage module; The main circuit is used to convert the output of the photovoltaic into a controllable output under the control of the control circuit so as to supply power to a load; The main circuit is provided with at least two conversion topologies with different voltage gain ranges; The voltage comparison unit and topology selection circuit obtain the output after the main circuit conversion, compare the current output value with a reference value, and select a conversion topology with a corresponding voltage gain range according to the magnitude relationship between the two; The energy storage module is connected to the photovoltaic through the main circuit; The energy storage module is used to store the excess electric energy of the photovoltaic and directly supply power to the load under set working conditions; The voltage comparison unit and topology selection circuit include a group of relays. The group of relays is connected into the main circuit and is used to switch the conversion topology of the main circuit to a first conversion topology according to a first topology switching signal, or switch the conversion topology of the main circuit to a second conversion topology according to a second topology switching signal, or switch the conversion topology of the main circuit to a third conversion topology according to a third topology switching signal; The second conversion topology includes: a first branch, a third branch, a switching tube and a main capacitor; The first branch includes a first inductor. One end of the first inductor serves as one end of the first branch and is connected to the photovoltaic end, and the other end serves as the other end of the first branch and is connected to the negative electrode of the switching tube; The third branch includes a second capacitor, a third capacitor, a sixth diode and a seventh diode. One end of the second capacitor and the cathode of the seventh diode are connected and then serve as the first end of the third branch and are connected between the first branch and the negative electrode of the switching tube. The other end of the second capacitor and the cathode of the sixth diode are connected and then serve as the second end of the third branch and are connected to one end of the main capacitor and the load end; One end of the third capacitor is connected to the anode of the sixth diode and then serves as the third end of the third branch and is connected between the positive electrode of the switching tube and the photovoltaic end. The other end of the third capacitor and the anode of the seventh diode are connected and then serve as the fourth end of the third branch and are connected to the other end of the main capacitor and the load end.

2. The new energy multi-mode electric vehicle charging pile according to claim 1, wherein, The voltage comparison unit and topology selection circuit further include: a comparator; The comparator is used to compare the output after the main circuit conversion with a first reference value and a second reference value. If it is less than the first reference value, the first topology switching signal is generated. If it is between the first reference value and the second reference value, the second topology switching signal is generated. If it is greater than the second reference value, the third topology switching signal is generated. The second reference value is greater than the first reference value.

3. The new energy multi-mode electric vehicle charging pile according to claim 2, characterized in that The first conversion topology includes: the first branch, a second branch, a main capacitor and a switching tube; The other end of the first branch is further connected to one end of the second branch; The second branch includes a fifth diode. The anode of the fifth diode serves as one end of the second branch and is connected between the first branch and the switching tube, and the cathode serves as the other end of the second branch and is connected to one end of the main capacitor and the load end; The other end of the main capacitor is respectively connected to the photovoltaic terminal, the positive electrode of the switching tube, and the load terminal; The positive electrode of the switching tube is connected to the photovoltaic terminal.

4. The new energy multi-mode electric vehicle charging pile according to claim 3, characterized in that, The voltage gain of the first conversion topology is specifically: Where G1 is the voltage gain of the first conversion topology, and d is the duty cycle of the switching tube controlled by the control circuit.

5. The new energy multi-mode electric vehicle charging pile according to claim 1, characterized in that, The voltage gain of the second conversion topology is specifically: Where G2 is the voltage gain of the first conversion topology, and d is the duty cycle of the switching tube controlled by the control circuit.

6. The new energy multi-mode electric vehicle charging pile according to claim 4, characterized in that, The third topology includes: a fourth branch, the second branch, the switching tube, and the main capacitor; The fourth branch includes a first diode, a second diode, a third diode, a fourth diode, a second inductor, a third inductor, and a first capacitor; The anodes of the first diode, the second diode, and one end of the third inductor are connected together and used as one end of the fourth branch to be connected to the photovoltaic terminal. The cathode of the second diode and one end of the first capacitor are connected and then connected to the anode of the third diode. The cathode of the first diode and the cathode of the third diode are connected and then connected to one end of the second inductor. The other end of the third inductor and the other end of the first capacitor are connected and then connected to the anode of the fourth diode. The cathode of the fourth diode and the other end of the second inductor are connected and used as the other end of the fourth branch to be respectively connected to the negative electrode of the switching tube and one end of the second branch.

7. The new energy multi-mode electric vehicle charging pile according to claim 6, characterized in that, The voltage gain of the third conversion topology is specifically: Where G3 is the voltage gain of the first conversion topology, and d is the duty cycle of the switching tube controlled by the control circuit.

8. The new energy multi-mode electric vehicle charging pile according to claim 6, wherein The number of the group of relays is 3. Among them, the first branch and the fourth branch are respectively connected to the main circuit through two static contacts of the first relay. The second branch is connected to the main circuit through one static contact of the second relay and one static contact of the third relay. The third branch is connected to the main circuit through the other static contact of the second relay and the other static contact of the third relay.

9. The new energy multi-mode electric vehicle charging pile according to claim 8, characterized in that, The comparator includes a first comparator and a second comparator. The process of the voltage comparison unit and the topology selection circuit selecting the conversion topology corresponding to the voltage gain range specifically includes: When the outputs after the conversion of the main circuit compared by the first comparator and the second comparator are less than the corresponding reference values, three low-level signals are output. The low-level signal output by the first comparator passes through a NOT gate to obtain a high-level signal, which is used as the control signal of the first relay to control the first branch to be connected to the main circuit. The two low-level signals output by the second comparator, one of the low-level signals is directly used as the control signal of the third relay to control one end of the second branch to be connected to the main circuit, and the other low-level signal passes through a NOT gate to obtain a high-level signal, which is used as the control signal of the second relay to control the other end of the second branch to be connected to the main circuit, so that the main circuit is switched to the first topology; When the outputs after transformation of the main circuit are between the first reference value and the second reference value as compared by the first comparator and the second comparator, a low-level signal and two high-level signals are output. The two high-level signals output by the first comparator serve as the control signals for the first relay and the third relay, respectively controlling the connection of the first branch to the main circuit and controlling the connection of the third end of the third branch to the main circuit. The high-level signal of the second comparator passes through a NOT gate to obtain a low-level signal, which serves as the control signal for the second relay to control the connection of the first end of the third branch to the main circuit, thereby switching the main circuit to the second conversion topology; When the outputs after transformation of the main circuit are both greater than the second reference value as compared by the first comparator and the second comparator, three high-level signals are output. The two high-level signals output by the first comparator pass through NOT gates to obtain two low-level signals, which serve as the control signals for the first relay and the third relay, controlling the connection of the first branch to the main circuit and controlling the connection of one end of the second branch to the circuit. The high-level signal of the second comparator directly serves as the control signal for the second relay to control the connection of the other end of the second branch to the main circuit, thereby switching the main circuit to the third conversion topology.

Images