Power converter, charging pile, control method and control device

Abstract

The invention discloses a power converter, a charging pile, a control method and a control device. The power converter comprises a controller and at least one power module, and the direct current output positive electrode of a power conversion circuit in each power module is connected with the positive electrode of a diode; the voltage sampling circuit is used for acquiring the anode voltage of the diode; the current sampling circuit is used for acquiring current flowing through the diode; the temperature sampling circuit is used for acquiring the temperature of the diode; the controller is used for obtaining the conduction voltage drop of the diode according to the current of the diode and the temperature of the diode; and controlling the output voltage of the power conversion circuit according to the anode voltage of the diode and the conduction voltage drop of the diode. In the embodiment of the invention, the anode voltage of the diode and the conduction voltage drop of the diode can truly reflect the output voltage of the power conversion circuit, the power conversion circuit is controlled according to the anode voltage of the diode and the conduction voltage drop of the diode, and the control accuracy of the power conversion circuit is improved.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a power converter, a charging pile, a control method and a control device. Background Art

[0002] The power converter is generally controlled in a closed-loop control manner, that is, the output voltage of the power converter is used as the feedback voltage of the control loop to control the power converter.

[0003] In order to protect the internal circuits in the power converter, a diode is added to the positive pole of the DC output of the power converter to prevent current backflow. In the related art, the output voltage of the diode is used as the feedback voltage of the control loop to control the power converter. However, the output voltage of the diode cannot truly reflect the output voltage of the power converter. Using it as the feedback voltage of the control loop of the power converter will cause deviation in the control of the power converter. Summary of the invention

[0004] Based on the above problems, the present application provides a power converter, a charging pile, a control method and a control device to improve the accuracy of power converter control.

[0005] The embodiments of the present application disclose the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a power converter, comprising: a controller and at least one power module, the power module comprising a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit and a temperature sampling circuit, the DC output positive pole of the power conversion circuit is connected to the anode of the diode; a voltage sampling circuit, used to obtain the anode voltage of the diode; a current sampling circuit, used to obtain the current flowing through the diode; a temperature sampling circuit, used to obtain the temperature of the diode; a controller, used to obtain the conduction voltage drop of the diode according to the current of the diode and the temperature of the diode; and control the output voltage of the power conversion circuit according to the anode voltage of the diode and the conduction voltage drop of the diode.

[0007] In a possible implementation, the controller is specifically configured to query a data table to obtain a conduction voltage drop of the diode according to a temperature of the diode and a current of the diode; the data table includes a corresponding relationship among temperature, current and conduction voltage drop.

[0008] In one possible implementation, the controller is specifically used to obtain at least four reference forward voltage drops corresponding to at least two groups of parameters, wherein each group of parameters includes a reference current and a reference temperature; and obtain the forward voltage drop of the diode based on the temperature of the diode, the current of the diode and at least four reference forward voltage drops.

[0009] In one possible implementation, the controller is also used to obtain at least four reference on-state voltage drops corresponding to at least two sets of parameters when the temperature of the diode does not hit the reference temperature in the data table, or the current of the diode does not hit the reference current in the data table, wherein each set of parameters includes a reference current and a reference temperature; and the on-state voltage drop of the diode is obtained based on the temperature of the diode, the current of the diode and the at least four reference on-state voltage drops.

[0010] In one possible implementation, the controller is specifically used to fit a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the first reference on-state voltage drop, and the second reference on-state voltage drop; to fit a sixth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop, and the fourth reference on-state voltage drop; and to fit the on-state voltage drop of the diode according to the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop, and the sixth reference on-state voltage drop. In a possible implementation, the controller is specifically used to fit a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop, and the fourth reference on-state voltage drop; and to fit the on-state voltage drop of the diode according to the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop, and the sixth reference on-state voltage drop.

[0011] In one possible implementation, the controller is specifically used to fit a seventh reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the first reference on-state voltage drop, and the third reference on-state voltage drop; to fit an eighth reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the second reference on-state voltage drop, and the fourth reference on-state voltage drop; and to fit the on-state voltage drop of the diode according to the temperature of the diode, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop, and the eighth reference on-state voltage drop. In a possible implementation, the controller is specifically used to fit a seventh reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the second reference on-state voltage drop, and the fourth reference on-state voltage drop; and to fit the on-state voltage drop of the diode according to the temperature of the diode, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop, and the eighth reference on-state voltage drop.

[0012] In one possible implementation, the controller is specifically used to use the average of the first reference on-state voltage drop, the second reference on-state voltage drop, the third reference on-state voltage drop and the fourth reference on-state voltage drop as the on-state voltage drop of the diode when two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference temperature and a first reference current corresponding to the first reference current, a second reference temperature and a first reference current corresponding to the first reference current, a third reference temperature and a second reference current corresponding to the first reference current, and a fourth reference temperature and a second reference current corresponding to the second reference current, the temperature of the diode is between the first reference temperature and the second reference temperature, and the current of the diode is between the first reference current and the second reference current.

[0013] In a possible implementation, when the power converter includes multiple power modules, the DC output positive electrodes of each power module are connected together through the cathodes of their corresponding diodes, and the DC output negative electrodes of each power module are connected together.

[0014] In the second aspect, an embodiment of the present application provides a charging pile, comprising: a power converter as in any embodiment of the first aspect; the input end of each power conversion circuit in the power converter is used to connect to the power grid, the output positive poles of each power conversion circuit are connected together through their respective corresponding diodes and connected to the charging positive pole of the vehicle to be charged, and the output negative poles of each power conversion circuit are connected together and connected to the charging negative pole of the vehicle to be charged.

[0015] In a third aspect, an embodiment of the present application provides a control method for a power converter, wherein the power converter includes at least one power module, the power module includes a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit, and a temperature sampling circuit; the DC side positive electrode of the power conversion circuit is connected to the anode of the diode; the voltage sampling circuit is used to obtain the anode voltage of the diode; the current sampling circuit is used to obtain the current flowing through the diode; the temperature sampling circuit is used to obtain the temperature of the diode;

[0016] Methods include:

[0017] The voltage drop of the diode is obtained according to the current of the diode and the temperature of the diode; the output voltage of the power conversion circuit is controlled according to the anode voltage of the diode and the conduction voltage drop of the diode.

[0018] In a possible implementation, the voltage drop of the diode is obtained according to the current of the diode and the temperature of the diode, including: querying a data table to obtain the conduction voltage drop of the diode according to the temperature of the diode and the current of the diode; the data table includes the correspondence between temperature, current and conduction voltage drop.

[0019] In one possible implementation, the voltage drop of the diode is obtained according to the current of the diode and the temperature of the diode, including: obtaining at least four reference conduction voltage drops corresponding to at least two groups of parameters; each group of parameters includes a reference current and a reference temperature; and obtaining the conduction voltage drop of the diode according to the temperature of the diode, the current of the diode and at least four reference conduction voltage drops.

[0020] In one possible implementation, the method also includes: when the temperature of the diode does not hit the reference temperature in the data table, or the current of the diode does not hit the reference current in the data table, obtaining at least four reference on-state voltage drops corresponding to at least two sets of parameters; each set of parameters includes a reference current and a reference temperature; and obtaining the on-state voltage drop of the diode based on the temperature of the diode, the current of the diode and at least four reference on-state voltage drops.

[0021] In a possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: fitting a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the first reference on-state voltage drop and the second reference on-state voltage drop; fitting a sixth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop and the fourth reference on-state voltage drop; fitting a diode on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop and the sixth reference on-state voltage drop.

[0022] In a possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: fitting a seventh reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the first reference on-state voltage drop and the third reference on-state voltage drop; fitting an eighth reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the second reference on-state voltage drop and the fourth reference on-state voltage drop; fitting the on-state voltage drop of the diode according to the temperature of the diode, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop and the eighth reference on-state voltage drop.

[0023] In one possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: when the temperature of the diode is between the first reference temperature and the second reference temperature, and the current of the diode is between the first reference current and the second reference current, the average value of the first reference on-state voltage drop, the second reference on-state voltage drop, the third reference on-state voltage drop and the fourth reference on-state voltage drop is used as the on-state voltage drop of the diode.

[0024] In a fourth aspect, an embodiment of the present application provides a control device, including a processor and a memory, the memory being used to store programs, instructions or codes, and the processor being used to execute the programs, instructions or codes in the memory to complete a control method for a power converter as in any embodiment of the third aspect.

[0025] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, characterized in that a computer program is stored therein, and the computer program is loaded by a processor to execute a control method for a power converter as in any embodiment of the third aspect.

[0026] The cathode voltage of the diode cannot truly reflect the output voltage of the power conversion circuit. Using it as the feedback voltage of the control loop of the power converter will cause deviation in the control of the power converter. To this end, an embodiment of the present application provides a power converter, which includes a controller and at least one power module, the power module includes a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit and a temperature sampling circuit, the DC side positive pole of the power conversion circuit is connected to the anode of the diode; the voltage sampling circuit is used to obtain the anode voltage of the diode; the current sampling circuit is used to obtain the current flowing through the diode; the temperature sampling circuit is used to obtain the temperature of the diode; the controller is used to obtain the conduction voltage drop of the diode according to the temperature of the diode and the current of the diode; the output voltage of the power conversion circuit is controlled according to the conduction voltage drop of the diode and the anode voltage of the diode. In the embodiment of the present application, the anode voltage of the diode and the conduction voltage drop of the diode can truly reflect the output voltage of the power conversion circuit, and the power conversion circuit is controlled according to the anode voltage of the diode and the conduction voltage drop of the diode, so as to improve the accuracy of the control of the power conversion circuit and the accuracy of the output voltage of the power conversion circuit. In addition, in the embodiments of the present application, the forward voltage drop of the diode takes into account the temperature of the diode and the current of the diode, thereby improving the accuracy of the forward voltage drop of the diode and further improving the accuracy of the power conversion circuit control and the accuracy of the output voltage of the power conversion circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 is a schematic diagram of a power converter;

[0029] Figure 2 A schematic diagram of a power converter provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of another power converter provided in an embodiment of the present application;

[0031] Figure 4 A control loop schematic diagram provided for an embodiment of the present application;

[0032] Figure 5 A schematic diagram of a variable relationship provided in an embodiment of the present application;

[0033] Figure 6 A schematic diagram of a method for calculating a conduction voltage drop provided in an embodiment of the present application;

[0034] Figure 7 A schematic diagram of another method for calculating the on-state voltage drop provided in an embodiment of the present application;

[0035] Figure 8 A schematic diagram of another method for calculating the on-state voltage drop provided in an embodiment of the present application;

[0036] Fig. 9 A schematic diagram of a charging pile provided in an embodiment of the present application;

[0037] Fig.10 A flow chart of a control method for a power converter provided in an embodiment of the present application;

[0038] Fig.11 A schematic diagram of a control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the solution of the present application, the following will be combined with the attached functional diagrams in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] The terms "first" and "second" in the specification and claims of this application are used to distinguish different objects rather than to describe a specific order of objects. For example, a first power module and a second power module are used to distinguish different power modules rather than to describe a specific order of power modules.

[0041] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0042] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two. For example, multiple processing units refer to two or more processing units, etc.; multiple elements refer to two or more elements, etc.

[0043] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the power converter including a first power module and a second power module is taken as an example below, and the application scenarios of the embodiments of the present application are further described in detail in combination with the drawings and specific implementation methods.

[0044] See also Figure 1 , which is a schematic diagram of a power converter.

[0045] like Figure 1 As shown, the first power module includes a power conversion circuit 1 and a diode D1, and the second power conversion module includes a power conversion circuit 2 and a diode D2. Among them, the output positive electrode of the power conversion circuit 1 is connected to the anode of the diode D1, the output positive electrode of the power conversion circuit 2 is connected to the anode of the diode D2, the cathode of the diode D1 and the cathode of the diode D2 are connected together, and the output negative electrode of the power conversion circuit 1 and the output negative electrode of the power conversion circuit 2 are connected together. When the first power module is in a working state with output voltage (the anode voltage Vo1' of the diode D1 is ≠ 0), Vo1' will pull up the entire parallel output bus voltage Vo; the second power module is in a standby state without output voltage (the anode voltage Vo2' of the diode D2 is 0). If the second power module uses Vo as the feedback voltage, it will misjudge that there is already voltage on its output side, which will cause the control of the second power module to deviate.

[0046] In addition, for a power converter including only one power module, the cathode voltage of the diode reflects the voltage at the user end rather than the actual output voltage of the power conversion circuit. If the cathode voltage of the diode is used as the feedback voltage, it will also cause deviations in the control of the power module.

[0047] To this end, the embodiment of the present application provides a power converter, which controls the power conversion circuit in the power module by the anode voltage of the diode in the power module and the forward voltage drop of the diode. The anode voltage of the diode and the forward voltage drop of the diode can truly reflect the output voltage of the power conversion circuit. The power conversion circuit is controlled according to the anode voltage of the diode and the forward voltage drop of the diode, thereby improving the accuracy of the control of the power conversion circuit and the output voltage accuracy of the power conversion circuit. In addition, in the embodiment of the present application, the forward voltage drop of the diode takes into account the temperature of the diode and the current of the diode, thereby improving the accuracy of the forward voltage drop of the diode, and further improving the accuracy of the control of the power conversion circuit and the output voltage accuracy of the power conversion circuit.

[0048] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0049] See also Figure 2, which is a schematic diagram of a power converter provided in an embodiment of the present application.

[0050] like Figure 2 As shown, the power converter includes a controller 1000 and at least one power module 2000. The power module 2000 includes a power conversion circuit 100, a diode D1, a voltage sampling circuit 200, a current sampling circuit 300 and a temperature sampling circuit 400. The DC output positive electrode of the power conversion circuit 100 is connected to the anode of the diode D1.

[0051] In the case where the power converter includes a plurality of power modules, the schematic diagram of the power converter is as follows: Figure 3 As shown, the output positive electrodes of each power module 2000 are connected together through the cathodes of their respective diodes, and the output negative electrodes of each power module 2000 are connected together. For example, the output positive electrode of power conversion circuit 1, the output positive electrode of power conversion circuit 2, ..., the output positive electrode of power conversion circuit n are connected together through the cathode of diode D1, the cathode of diode D2, ..., the cathode of diode Dn, respectively, and the output negative electrode of power conversion circuit 1, the output negative electrode of power conversion circuit 2, ..., the output negative electrode of power conversion circuit n are connected together.

[0052] Exemplarily, in the embodiments of the present application, the type of the power conversion circuit 100 is not specifically limited. For example, the power conversion circuit 100 may be an AC / DC power conversion circuit.

[0053] The following will introduce the control method of any power module in combination with specific embodiments.

[0054] The voltage sampling circuit 100 is used to obtain the anode voltage V of the diode D1. o '.

[0055] The form of the voltage sampling circuit is not specifically limited in the embodiments of the present application. For example, the voltage sampling circuit 100 may be a resistor voltage divider circuit, a differential amplifier circuit, an integration circuit, etc. It should be understood that the voltage sampling circuit is a mature technical means in the field and will not be described in detail here.

[0056] The current sampling circuit 200 is used to obtain the current I flowing through the diode D1. F .

[0057] The form of the current sampling circuit is not specifically limited in the embodiments of the present application. For example, the current sampling circuit 200 may be a current voltage divider circuit and a Hall sampling circuit, etc. It should be understood that the current sampling circuit is a mature technical means in the art and will not be described in detail here.

[0058] The temperature sampling circuit 300 is used to obtain the temperature T of the diode D1. D .

[0059] For example, the embodiment of the present application can obtain the temperature T of the diode D1 by placing the thermistor R1 near the diode D1. d .

[0060] The controller 1000 is used to control the current I of the diode D1 according to the current I f and the temperature T of diode D1 D , get the conduction voltage drop of diode D1; according to the anode voltage V of diode D1 o ' and the conduction voltage drop of the diode to control the output voltage of the power conversion circuit 100.

[0061] For example, the control loop diagram of the power conversion circuit is as follows: Figure 4 As shown, first, the anode voltage V of the diode is obtained by the voltage sampling circuit, the current sampling circuit and the temperature sampling circuit respectively. o ', the diode current I F and the diode temperature T D ; Secondly, according to the diode current I F and the diode temperature T D Get the diode conduction voltage drop V F ; Then, according to the voltage reference value V ref , the anode voltage of the diode V o ' and the diode's forward voltage drop V F , that is (V ref -(V o '-V F )) as the input of the PI control link; finally, the controller uses a voltage loop or a current loop control method to control the output voltage V of the power conversion circuit based on the output value of the PI control link. o It should be understood that voltage loop and current loop control are mature technical means in this field and will not be described in detail here.

[0062] In the embodiment of the present application, the anode voltage of the diode D1 and the conduction voltage drop of the diode D1 truly reflect the output voltage of the power conversion circuit, and the difference between the anode voltage of the diode D1 and the conduction voltage drop of the diode is used as the feedback voltage of the control loop of the power conversion circuit, thereby improving the accuracy of the control of the power conversion circuit and the output voltage accuracy of the power conversion circuit, and further improving the current sharing effect of each power module when the power converter includes multiple power modules. In addition, in the embodiment of the present application, the conduction voltage drop of the diode takes into account the temperature of the diode and the current of the diode, improves the accuracy of the conduction voltage drop of the diode, and further improves the accuracy of the control of the power conversion circuit and the output voltage reduction of the power conversion circuit.

[0063] In the following, in conjunction with the embodiments, a method for obtaining the on-state voltage drop of a diode through the temperature of the diode and the current of the diode is introduced.

[0064] In a possible embodiment, the controller is based on the temperature T of the diode. D and the diode current I F , query the data table to get the diode's conduction voltage drop; the data table includes the temperature T D 、Current I F The corresponding relationship between the conduction voltage drop and the on-state voltage drop is shown in Table 1 below:

[0065] Table 1

[0066]

[0067] As shown in Table 1, the temperature T D1 and I F1 Corresponding conduction voltage drop V F1,1 , temperature T D2 and I F1 Corresponding conduction voltage drop V F2,1 ...Temperature T Dj and I F1 Corresponding conduction voltage drop V Fj,1 Temperature T D1 and I F2 Corresponding conduction voltage drop V F1,2 , temperature T D2 and I F2 Corresponding conduction voltage drop V F2,2 ...Temperature T Dj and I F2 Corresponding conduction voltage drop V Fj,2 ; ...; Temperature T D1 and I Fi Corresponding conduction voltage drop V F1,i , temperature T D2 and I Fi Corresponding conduction voltage drop V F2,i ...Temperature T Dj and I Fi Corresponding conduction voltage drop V Fj,i .

[0068] Exemplarily, the current of the diode acquired by the current sampling circuit is I F1 The temperature of the diode obtained by the temperature sampling circuit is T D1 , then by looking up the above Table 1, we can know that the conduction voltage drop of the diode is V F1,1 ; The current sampling circuit obtains the diode current I F1 The temperature of the diode obtained by the temperature sampling circuit is T D2 , then by looking up the above Table 1, we can know that the conduction voltage drop of the diode is VF2,1 , and so on.

[0069] In a possible embodiment, the controller obtains at least four reference forward voltage drops corresponding to at least two groups of parameters; each group of parameters includes a reference current and a reference temperature; the forward voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference forward voltage drops.

[0070] In the embodiment of the present application, the two sets of parameters can be the temperature I of any diode. F and the current T of any diode D For example, the first set of parameters includes the diode current I F1 and the diode temperature T D1 The second set of parameters includes the diode current I F2 and the diode temperature T D2 ; Alternatively, the first set of parameters includes the diode current I F2 and the diode temperature T D1 The second set of parameters includes the diode current I F1 and the diode temperature T D2 For ease of understanding, in the subsequent embodiments, the first set of parameters will include the first reference temperature T Dm and the first reference current I Fn The second set of parameters includes a second reference temperature T Dm+1 and the second reference current I Fn+1 Take this as an example for introduction.

[0071] Exemplarily, the first set of parameters includes a first reference temperature T Dm and the first reference current I Fn The second set of parameters includes a second reference temperature T Dm+1 and the second reference current I Fn+1 In the case of Dm and the first reference current I Fn The corresponding first reference conduction voltage drop V Fm,n , the second reference temperature T Dm+1 and the first reference current I Fn The corresponding second reference conduction voltage drop V Fm+1,n , the first reference temperature T Dm and the second reference current I Fn+1 The corresponding third reference conduction voltage drop V Fm,n+1 and the second reference temperature T Dm+1 and the second reference current I Fn+1 The corresponding fourth reference conduction voltage drop V Fm+1,n+1 , where the first reference temperature T Dm , the first reference current I Fn, the second reference temperature T Dm+1 , the second reference current I Fn+1 , the first reference conduction voltage drop V Fm,n , the second reference conduction voltage drop V Fm+1,n , the third reference conduction voltage drop V Fm,n+1 and the fourth reference conduction voltage drop V Fm+1,n+1 The corresponding relationship between Figure 5 shown.

[0072] In one possible implementation, the controller fits a fifth reference on-state voltage drop based on the temperature of the diode, the first reference temperature, the second reference temperature, the first reference on-state voltage drop, and the second reference on-state voltage drop; fits a sixth reference on-state voltage drop based on the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop, and the fourth reference on-state voltage drop; and fits the on-state voltage drop of the diode based on the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop, and the sixth reference on-state voltage drop.

[0073] Among them, the method of calculating the conduction voltage drop of the diode is as follows Figure 6 As shown, through the following formula (1), the controller is based on the temperature T of the diode Dnw , the first reference temperature T Dm , the second reference temperature T Dm+1 , the first reference conduction voltage drop V Fm,n and the second reference conduction voltage drop V Fm+1,n , the fifth reference on-state voltage drop V is obtained by fitting Fnw,n .

[0074]

[0075] The controller uses the following formula (2) to calculate the diode temperature T Dnw , the first reference temperature T Dm , the second reference temperature T Dm+1 , the third reference conduction voltage drop V Fm,n+1 and the fourth reference conduction voltage drop V Fm+1,n+1 , the fifth reference on-state voltage drop V is obtained by fitting Fnw,n+1 .

[0076]

[0077] The controller uses the following formula (3) to calculate the diode current I Fnw , the first reference current I Fn , the second reference current I Fn+1 , the fifth reference conduction voltage drop V Fnw,n and the sixth reference conduction voltage drop V Fnw,n+1 , the fifth reference on-state voltage drop V is obtained by fitting Fnw,nw.

[0078]

[0079] By combining the above formula (1), formula (2) and formula (3), the forward voltage drop of the diode can be calculated.

[0080] In another possible implementation, the controller fits a seventh reference on-state voltage drop based on the diode current, the first reference current, the second reference current, the first reference on-state voltage drop and the third reference on-state voltage drop; fits an eighth reference on-state voltage drop based on the diode current, the first reference current, the second reference current, the second reference on-state voltage drop and the fourth reference on-state voltage drop; and fits the diode on-state voltage drop based on the diode temperature, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop and the eighth reference on-state voltage drop.

[0081] Among them, the method of calculating the conduction voltage drop of the diode is as follows Figure 7 As shown, through the following formula (4), the controller is based on the diode current I Fnw , the first reference current I Fn , the second reference current I Fn+1 , the first reference conduction voltage drop V Fm,n and the third reference on-state voltage drop V Fm,n+1 , the seventh reference on-state voltage drop V is obtained by fitting Fm,nw .

[0082]

[0083] The controller uses the following formula (5) to calculate the diode current I Fnw , the first reference current I Fn , the second reference current I Fn+1 , the second reference conduction voltage drop V Fm+1,n and the fourth reference conduction voltage drop V Fm+1,n+1 , the eighth reference on-state voltage drop V is obtained by fitting Fm+1,nw .

[0084]

[0085] The controller uses the following formula (6) to calculate the diode temperature T Dnw , the first reference temperature T Dn , the second reference temperature T Dn+1 , the seventh reference conduction voltage drop V Fm,nw and the eighth reference conduction voltage drop V Fm+1,nw , the diode conduction voltage drop V is obtained by fitting Fnw,nw .

[0086]

[0087] By combining the above formula (4), formula (5) and formula (6), the conduction voltage drop of the diode can be calculated.

[0088] In one possible implementation, the forward voltage drop of the diode is calculated as follows: Figure 8 As shown, according to the following formula (7), when the temperature of the diode is between the first reference temperature and the second reference temperature, and the current of the diode is between the first reference current and the second reference current, the controller uses the average value of the first reference conduction voltage drop, the second reference conduction voltage drop, the third reference conduction voltage drop and the fourth reference conduction voltage drop as the conduction voltage drop of the diode.

[0089]

[0090] In another possible embodiment, after the controller obtains the current and temperature of the diode, it first searches the data table for the on-state voltage drop of the diode corresponding to the current and temperature of the diode. When the temperature of the diode does not hit the reference temperature in the data table, or the current of the diode does not hit the reference current in the data table, at least four reference on-state voltage drops corresponding to at least two sets of parameters are obtained; each set of parameters includes a reference current and a reference temperature; the on-state voltage drop of the diode is obtained based on the temperature of the diode, the current of the diode and at least four reference on-state voltage drops.

[0091] It should be understood that the above embodiment is consistent with the implementation method of the aforementioned embodiment, that is, the on-state voltage drop of the diode is calculated according to the aforementioned formula (1), formula (2) and formula (3), or the conduction of the diode is calculated according to the aforementioned formula (4), formula (5) and formula (6), or the on-state voltage drop of the diode is calculated according to the aforementioned formula (7), which will not be repeated here.

[0092] In addition, the present application embodiment also provides a charging pile, the schematic diagram of the charging pile is as shown in Fig. 9 As shown, the input end of each power conversion circuit in the power converter is used to connect to the power grid, the output negative poles of each power conversion circuit are connected together, and the output positive poles of each power conversion circuit are connected together through their respective corresponding diodes and connected to the vehicle to be charged. For example, the input ends of power conversion circuit 1, power conversion circuit 2...power conversion circuit n are connected to the power grid, the output positive pole of power conversion circuit 1, the output positive pole of power conversion circuit 2...the output positive pole of power conversion circuit n are connected together through the cathode of diode D1, the cathode of diode D2...the cathode of diode Dn and connected to the charging positive pole of the vehicle to be charged, and the output negative pole of power conversion circuit 1, the output negative pole of power conversion circuit 2...the output negative pole of power conversion circuit n are connected together and connected to the charging negative pole of the vehicle to be charged.

[0093] In the embodiment of the present application, the anode voltage of the diode D1 and the conduction voltage drop of the diode D1 truly reflect the output voltage of the power conversion circuit, and the difference between the anode voltage of the diode D1 and the conduction voltage drop of the diode is used as the feedback voltage of the control loop of the power conversion circuit, thereby improving the accuracy of the control of the power conversion circuit and the output voltage accuracy of the power conversion circuit, and further improving the current sharing effect between the power modules when the charging pile includes multiple power modules. In addition, in the embodiment of the present application, the conduction voltage drop of the diode takes into account the temperature of the diode and the current of the diode, improves the accuracy of the conduction voltage drop of the diode, and further improves the accuracy of the control of the power conversion circuit and the output voltage reduction of the power conversion circuit.

[0094] Based on a power converter provided in the above embodiment, an embodiment of the present application further provides a control method for a power converter, which is described in detail below in conjunction with the accompanying drawings.

[0095] See also Fig.10 , which is a flow chart of a control method for a power converter provided in an embodiment of the present application.

[0096] The power converter includes a controller and at least one power module. The power module includes a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit and a temperature sampling circuit. The DC output positive pole of the power conversion circuit is connected to the anode of the diode; the voltage sampling circuit is used to obtain the anode voltage of the diode; the current sampling circuit is used to obtain the current flowing through the diode; and the temperature sampling circuit is used to obtain the temperature of the diode.

[0097] Methods include:

[0098] S110: Obtaining a conduction voltage drop of the diode according to the current of the diode and the temperature of the diode.

[0099] S120: Controlling the output voltage of the power conversion circuit according to the anode voltage of the diode and the conduction voltage drop of the diode.

[0100] In the embodiment of the present application, the anode voltage of the diode and the forward voltage drop of the diode truly reflect the output voltage of the power conversion circuit, and the difference between the anode voltage of the diode and the forward voltage drop of the diode is used as the feedback voltage of the control loop of the power conversion circuit, thereby improving the accuracy of the control of the power conversion circuit and the output voltage accuracy of the power conversion circuit, and further improving the current sharing effect of each power module when the power converter includes multiple power modules. In addition, in the embodiment of the present application, the forward voltage drop of the diode takes into account the temperature of the diode and the current of the diode, improves the accuracy of the forward voltage drop of the diode, and further improves the accuracy of the control of the power conversion circuit and the output voltage reduction of the power conversion circuit.

[0101] In a possible implementation, the voltage drop of the diode is obtained according to the current of the diode and the temperature of the diode, including: querying a data table to obtain the conduction voltage drop of the diode according to the temperature of the diode and the current of the diode; the data table includes the correspondence between temperature, current and conduction voltage drop.

[0102] In one possible implementation, the voltage drop of the diode is obtained according to the current of the diode and the temperature of the diode, including: obtaining at least four reference conduction voltage drops corresponding to at least two groups of parameters; each group of parameters includes a reference current and a reference temperature; and obtaining the conduction voltage drop of the diode according to the temperature of the diode, the current of the diode and at least four reference conduction voltage drops.

[0103] In one possible implementation, the method also includes: when the temperature of the diode does not hit the reference temperature in the data table, or the current of the diode does not hit the reference current in the data table, obtaining at least four reference on-state voltage drops corresponding to at least two sets of parameters; each set of parameters includes a reference current and a reference temperature; and obtaining the on-state voltage drop of the diode based on the temperature of the diode, the current of the diode and at least four reference on-state voltage drops.

[0104] In a possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: fitting a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the first reference on-state voltage drop and the second reference on-state voltage drop; fitting a sixth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop and the fourth reference on-state voltage drop; fitting a diode on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop and the sixth reference on-state voltage drop.

[0105] In a possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: fitting a seventh reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the first reference on-state voltage drop and the third reference on-state voltage drop; fitting an eighth reference on-state voltage drop according to the current of the diode, the first reference current, the second reference current, the second reference on-state voltage drop and the fourth reference on-state voltage drop; fitting the on-state voltage drop of the diode according to the temperature of the diode, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop and the eighth reference on-state voltage drop.

[0106] In one possible implementation, the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and the on-state voltage drop of the diode is obtained according to the temperature of the diode, the current of the diode and at least four reference on-state voltage drops, including: when the temperature of the diode is between the first reference temperature and the second reference temperature, and the current of the diode is between the first reference current and the second reference current, taking the average of the first reference on-state voltage drop, the second reference on-state voltage drop, the third reference on-state voltage drop and the fourth reference on-state voltage drop as the on-state voltage drop of the diode.

[0107] In one possible implementation, see Fig.11 , which is a schematic diagram of a control device provided in an embodiment of the present application.

[0108] The control device may include a memory 1011 and a processor 1012. The processor 1012 may be connected to the power converter and may drive switches in each power conversion circuit in the power converter. Fig.11As shown, the memory can be a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM memory, an Electronic Programmable ROM (EPROM), a register, a hard disk, a removable disk, etc.

[0109] The memory 1011 can store computer instructions. When the computer instructions stored in the memory 1011 are executed by the processor 1012, the processor 1012 can be used to execute the control method. The memory 1011 can also store data, for example, information such as the preset range and preset threshold involved in the above embodiments.

[0110] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (digital subscriber line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, data center, etc. that includes one or more available media integrated. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), or a semiconductor medium (e.g., a solid state drive (solid statedisk, SSD)), etc.

[0111] The present application also provides a readable storage medium for storing the method provided in the above embodiment, for example, a random access memory (RAM), a flash memory, a read only memory (ROM), an EPROM memory, an electronic programmable ROM (EPROM), a register, a hard disk, a removable disk or any other form of storage medium in the art.

[0112] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the method disclosed in the embodiment, since it corresponds to the product embodiment disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the product embodiment part.

[0113] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power converter, characterized in that: include: A controller and at least one power module, wherein the power module includes a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit and a temperature sampling circuit, and the DC output positive electrode of the power conversion circuit is connected to the anode of the diode; The voltage sampling circuit is used to obtain the anode voltage of the diode; The current sampling circuit is used to obtain the current flowing through the diode; The temperature sampling circuit is used to obtain the temperature of the diode; The controller is used to obtain the conduction voltage drop of the diode according to the current of the diode and the temperature of the diode; and control the output voltage of the power conversion circuit according to the anode voltage of the diode and the conduction voltage drop of the diode.

2. The power converter according to claim 1, characterized in that: The controller is specifically used to query a data table to obtain the conduction voltage drop of the diode according to the temperature of the diode and the current of the diode; the data table includes the corresponding relationship between temperature, current and conduction voltage drop.

3. The power converter according to claim 1, characterized in that: The controller is specifically used to obtain at least four reference on-state voltage drops corresponding to at least two groups of parameters, wherein each group of parameters includes a reference current and a reference temperature; and obtain the on-state voltage drop of the diode according to the temperature of the diode, the current of the diode and the at least four reference on-state voltage drops.

4. The power converter according to claim 2, characterized in that: The controller is also used to obtain at least four reference on-state voltage drops corresponding to at least two groups of parameters when the temperature of the diode does not hit the reference temperature in the data table, or the current of the diode does not hit the reference current in the data table, wherein each group of parameters includes a reference current and a reference temperature; and obtain the on-state voltage drop of the diode based on the temperature of the diode, the current of the diode and the at least four reference on-state voltage drops.

5. The power converter according to claim 3 or 4, characterized in that: The controller is specifically used to fit a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the first reference voltage drop, and the second reference on-state voltage drop; to fit a sixth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop, and the fourth reference on-state voltage drop; and to fit the on-state voltage drop of the diode according to the current of the diode, the first reference current, the second reference current, the fifth reference on-state voltage drop, and the sixth reference on-state voltage drop. The controller is specifically used to fit a fifth reference on-state voltage drop according to the temperature of the diode, the first reference temperature, the second reference temperature, the third reference on-state voltage drop, and the fourth reference on-state voltage drop; when the two groups of parameters include a first reference temperature, a first reference current, a second reference current, the fifth reference on-state voltage drop, and the sixth reference on-state voltage drop.

6. The power converter according to claim 3 or 4, characterized in that: The controller is specifically used to obtain a seventh reference on-state voltage drop by fitting according to the current of the diode, the first reference current, the second reference current, the first reference on-state voltage drop, and the third reference on-state voltage drop, when the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature, and a second reference current, and the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current; An eighth reference on-state voltage drop is obtained by fitting based on the current of the diode, the first reference current, the second reference current, the second reference on-state voltage drop and the fourth reference on-state voltage drop; and the on-state voltage drop of the diode is obtained by fitting based on the temperature of the diode, the first reference temperature, the second reference temperature, the seventh reference on-state voltage drop and the eighth reference on-state voltage drop.

7. The power converter according to claim 3 or 4, characterized in that: The controller is specifically used for, when the two groups of parameters include a first reference temperature, a first reference current, a second reference temperature and a second reference current, the reference on-state voltage drop includes a first reference on-state voltage drop corresponding to the first reference temperature and the first reference current, a second reference on-state voltage drop corresponding to the second reference temperature and the first reference current, a third reference on-state voltage drop corresponding to the first reference temperature and the second reference current, and a fourth reference on-state voltage drop corresponding to the second reference temperature and the second reference current, and when the temperature of the diode is between the first reference temperature and the second reference temperature and the current of the diode is between the first reference current and the second reference current, the average value of the first reference on-state voltage drop, the second reference on-state voltage drop, the third reference on-state voltage drop and the fourth reference on-state voltage drop is used as the on-state voltage drop of the diode.

8. The power converter according to any one of claims 1 to 7, characterized in that: In the case where the power converter includes a plurality of power modules, the DC output positive electrodes of the power modules are connected together through the cathodes of their respective corresponding diodes, and the DC output negative electrodes of the power modules are connected together.

9. A charging pile, characterized in that: include: A power converter as claimed in any one of claims 1 to 8; The input end of each power conversion circuit in the power converter is used to connect to the power grid, the output positive poles of each power conversion circuit are connected together through their corresponding diodes and connected to the charging positive pole of the vehicle to be charged, and the output negative poles of each power conversion circuit are connected together and connected to the charging negative pole of the vehicle to be charged.

10. A method for controlling a power converter, characterized in that: The power converter comprises at least one power module, and the power module comprises a power conversion circuit, a diode, a voltage sampling circuit, a current sampling circuit and a temperature sampling circuit; the DC side positive pole of the power conversion circuit is connected to the anode of the diode; the voltage sampling circuit is used to obtain the anode voltage of the diode; The current sampling circuit is used to obtain the current flowing through the diode; The temperature sampling circuit is used to obtain the temperature of the diode; The method comprises: Obtaining a voltage drop of the diode according to the current of the diode and the temperature of the diode; The output voltage of the power conversion circuit is controlled according to the anode voltage of the diode and the conduction voltage drop of the diode.

11. A control device, characterized in that: It comprises a processor and a memory, wherein the memory is used to store programs, instructions or codes, and the processor is used to execute the programs, instructions or codes in the memory to complete the control method of the power converter as claimed in claim 10.

12. A computer-readable storage medium, characterized in that: A computer program is stored, and the computer program is loaded by a processor to execute the control method of the power converter as claimed in claim 10.

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