A parameter identification method and device for a multi-channel ISOS-IPT system

Abstract

The present invention discloses a parameter identification method and device for a multi-channel ISOS-IPT system. n The multi-channel system consists of channels. When it enters the steady state, it measures the effective value of the inverter output voltage, effective value of the current, phase difference and other ( n 2) The inverter input DC voltage of each channel can realize the identification of mutual inductance, equivalent load and actual load of all channels. The present invention has fewer measurement parameters, saves system cost and reduces system complexity.

Description

Technical Field

[0001] The present invention belongs to the field of inductive power transmission, and more specifically, relates to a parameter identification method and device for a multi-channel ISOS-IPT system. Background Art

[0002] Inductive Power Transfer (IPT) technology has attracted widespread attention due to its advantages such as contactless power supply, flexibility, convenience and high safety. Research results and applications have been extended to industries including electric vehicles, medical equipment and rail transit. Currently, most common IPT systems are single-channel systems, that is, the system only transmits energy through a single coupling coil. Single-channel IPT systems are constrained by power electronic devices and have limited output power, which cannot meet the high-power power supply requirements of rail transit, ship shore-based power supply, etc. In order to meet the high-power wireless charging needs of equipment such as unmanned aerial vehicles, an input-series output-series (ISOS) multi-channel system came into being, referred to as the ISOS-IPT system.

[0003] In the actual operation of the ISOS-IPT system, the relative positions of the coupled coils of each channel will be offset, which will cause changes in mutual inductance and uneven input and output voltage and power of each channel. If things go on like this, it will seriously affect the service life of the entire system. Therefore, voltage equalization control is a problem that must be solved by the ISOS system. Traditional voltage equalization control detects voltage and current through sensors on the secondary side, and transmits the values ​​to the primary side through wireless communication, and then calculates the mutual inductance and equivalent load of the coils of each channel, and uses this as the basis for voltage equalization control. Problems with this method: (1) The use of a wireless communication module to implement feedback on the charging parameters on the secondary side increases the cost and complexity of the IPT system, which is n Channel system, the number of sensors will be 2 n (2) When wireless communication is used for information transmission, the transmission delay is relatively large, which affects the dynamic response speed of the voltage equalization control.

[0004] The prior art also proposes some parameter identification methods for single-channel IPT systems based on primary side parameters, but these parameter identification methods are only applicable to single-channel IPT systems. If they are directly applied to multi-channel IPT systems, they need to be measured from the primary side. n This increases the number of sensors and makes the system more complex. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a parameter identification method and device for a multi-channel ISOS-IPT system, which has fewer measurement parameters, saves system cost and reduces system complexity.

[0006] To achieve the above object, according to one aspect of the present invention, a parameter identification method for a multi-channel ISOS-IPT system is provided, wherein the multi-channel ISOS-IPT system comprises n IPT channels, n ≥2, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier, and the parameter identification method includes the steps of:

[0007] Adjust the system circuit parameters, so that i The secondary side circuit of each channel is in resonance. i The primary side circuit of each channel is in ZVS state;

[0008] Get the total system input voltage and measure the i The effective value of the fundamental voltage output of each channel inverter U i , No. i The effective value of the fundamental current on the primary coil of each channel I i , No. i The phase difference between the fundamental voltage and fundamental current of the inverter output of each channel φ i and the rest n -2 channels of inverter input DC voltage, the first k The inverter input DC voltage of each channel is recorded as , k ≠ i ;

[0009] according to U i , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden , No. i Mutual inductance identification value of each channel M i_iden , No. i Identification value of the rectifier output voltage of each channel U oi_iden and iIdentification value of rectifier output current of each channel I oi_iden ;

[0010] Will I oi_iden Equivalent to k Identification value of rectifier output current of each channel I ok_iden ,according to and U oi_iden Calculate the k Identification value of rectifier output current of each channel U ok_iden ,according to I ok_iden and U ok_iden Calculate the k Equivalent load identification value of each channel , No. k Mutual inductance identification value of each channel M k_iden and total system load .

[0011] Furthermore, according to U i , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden Includes steps:

[0012] The first i The equivalent load of the rectifier of each channel is regarded as a resistive-inductive load, and the i The resistance of the equivalent load of the channel rectifier The expression of inductance The expression and i Channel primary side reflection impedance Z ri Expression of

[0013] according to U i , I i and φ i calculate Z ri the values ​​of the real and imaginary parts, and Z ri Ratio coefficient of real part to imaginary part ;

[0014] according to The expression of inductance The expression is determined R Li_iden about The expression of Calculation of the value R Li_iden .

[0015] Further, i Mutual inductance identification value of each channel M i_iden The calculation steps include:

[0016] according to R Li_iden Calculation of the value Identification value R eqi_iden and Identification value X eqi_iden ;

[0017] according to R eqi_iden , X eqi_iden , Z ri Calculation of the real and imaginary values M i_iden .

[0018] Further, U oi_iden and I oi_iden The calculation includes the following steps:

[0019] According to the circuit parameters, the i The transfer function of the rectifier input voltage and the inverter output voltage is G ui Expression of

[0020] according to R eqi_iden , X eqi_iden , M i_iden as well as G ui The expression calculation of G ui The value of

[0021] according to U i The measured values ​​and G ui The calculated value of i Identification value of channel secondary voltage Ureci_iden ;

[0022] according to U reci_iden calculate U oi_iden and I oi_iden .

[0023] Further,

[0024] ;

[0025] ;

[0026] ;

[0027] ;

[0028] In the formula, Indicates i Inverter DC input voltage for the channel.

[0029] Furthermore, the k Mutual inductance identification value of each channel M k_iden The calculation includes the following steps:

[0030] The first k The equivalent load of each channel rectifier is regarded as a resistive inductive load. calculate k Identification value of the resistance of the equivalent load of the rectifier of each channel R eqk_iden and the identification value of the inductance X eqk_iden ;

[0031] Calculate the k Secondary current identification value of each channel ;

[0032] according to R eqk_iden , X eqk_iden and calculate M k_iden .

[0033] Furthermore, each IPT channel adopts an SS compensation network, the primary side compensation network of each channel includes a primary side series compensation capacitor and a primary side parasitic resistor, and the secondary side compensation network of each channel includes a secondary side series compensation capacitor and a secondary side parasitic resistor. R Li_iden The calculation formula is:

[0034] ;

[0035] ;

[0036] ;

[0037] ;

[0038] ;

[0039] In the formula, Indicates i The secondary coil self-inductance of each channel, Indicates i The secondary side series compensation capacitor of each channel, Re[ Z ri ]express Z ri The real part of Im[ Z ri ]express Z ri The imaginary part of Indicates i The self-inductance of the primary coil of each channel, Indicates i The primary side series compensation capacitor of each channel, Indicates i The primary side parasitic resistance of each channel, is the inverter operating angular frequency;

[0040] M i_iden The calculation formula is:

[0041] ;

[0042] ;

[0043] ;

[0044] In the formula, Indicates i The secondary side parasitic resistance of each channel;

[0045] U oi_iden and I oi_iden The calculation formula is:

[0046] ;

[0047] In the formula, U reci_iden For the iIdentification value of the channel secondary voltage, , , They are all auxiliary calculation symbols.

[0048] Furthermore, each IPT channel adopts an SS compensation network, the primary side compensation network of each channel includes a primary side series compensation capacitor and a primary side parasitic resistor, and the secondary side compensation network of each channel includes a secondary side series compensation capacitor and a secondary side parasitic resistor. M k_iden The calculation formula is:

[0049] ;

[0050] ;

[0051] In the formula, Indicates k The effective value of the fundamental voltage output by each channel inverter, Indicates k The primary side parasitic resistance of each channel, Indicates k The secondary side parasitic resistance of each channel, Indicates k The primary side reactance of each channel, Indicates k The secondary side reactance of each channel, , , They are all auxiliary calculation symbols. is the inverter operating angular frequency.

[0052] According to another aspect of the present invention, a parameter identification device for a multi-channel ISOS-IPT system is provided, wherein the multi-channel ISOS-IPT system comprises n IPT channels, n ≥2, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier, and the parameter identification device includes:

[0053] The control module is used to adjust the system circuit parameters. i The secondary side circuit of each channel is in resonance. i The primary side circuit of each channel is in ZVS state;

[0054] The measurement module is used to obtain the total input voltage of the system and measure the i The effective value of the fundamental voltage output of each channel inverterU i , No. i The effective value of the fundamental current on the primary coil of each channel I i , No. i The phase difference between the fundamental voltage and fundamental current of the inverter output of each channel φ i and the rest n -2 channels of inverter input DC voltage, the first k The inverter input DC voltage of each channel is recorded as , k ≠ i ;

[0055] Identification module, used to U i , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden , No. i Mutual inductance identification value of each channel M i_iden , No. i Identification value of the rectifier output voltage of each channel U oi_iden and i Identification value of rectifier output current of each channel I oi_iden , also used to I oi_iden Equivalent to k Identification value of rectifier output current of each channel I ok_iden ,according to and U oi_iden Calculate the k Identification value of rectifier output current of each channel U ok_iden ,according to I ok_iden and U ok_iden Calculate the k Equivalent load identification value of each channel , No. k Mutual inductance identification value of each channel M k_iden and total system load .

[0056] In general, the above technical solutions conceived by the present invention have beneficial effects compared with the prior art:

[0057] The present invention proposes a parameter identification method and device for a multi-channel ISOS-IPT system, which realizes multiple mutual inductances and load identification of the system by measuring electrical parameters output by the inverter, reduces the number of measured parameters, saves system cost, and reduces system complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 is an architecture diagram of a multi-channel ISOS-IPT system according to an embodiment of the present invention;

[0059] Figure 2 is a single-channel equivalent circuit diagram of a multi-channel ISOS-IPT system according to an embodiment of the present invention;

[0060] Figure 3 It is a system flow chart of a parameter identification method of a multi-channel ISOS-IPT system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] Unless otherwise specified, "plurality" means two or more.

[0063] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0064] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0065] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0066] The present invention provides a parameter identification method and device for a multi-channel ISOS-IPT system. n Channels n Channel system, n ≥2, by measuring the inverter output fundamental voltage RMS value, fundamental current RMS value, phase difference and other n -2 channels of inverter input DC voltage can realize the identification of all channel mutual inductance, equivalent load and actual load. Compared with the traditional IPT system using wireless communication module, this system does not require a communication module, saving system cost and reducing system complexity.

[0067] like Figure 1 As shown, the multi-channel ISOS-IPT system of the embodiment of the present invention includes n IPT channels, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, and the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier.

[0068] For i For each channel, the working process is as follows: i The inverter of each channel passes the DC voltage U di Drive, where U di For the voltage divider capacitor C di The capacitor voltage on the secondary side is converted by the inverter to a high-frequency square wave voltage. The high-frequency AC current passes through the primary side compensation network, generates a sinusoidal voltage on the primary side of the coupling coil, and transmits the energy to the secondary side through electromagnetic induction. On the secondary side, the high-frequency sinusoidal current flows through the secondary side compensation network, the uncontrolled rectifier and the filter capacitor, and then supplies the load. R L powered by.

[0069] A parameter identification method of a multi-channel ISOS-IPT system according to an embodiment of the present invention comprises the steps of:

[0070] S101, adjust the system circuit parameters, so thati The secondary side circuit of each channel is in resonance. i The primary side circuit of each channel is in ZVS state, that is, zero voltage switching state;

[0071] S102, obtain the total input voltage of the system, measure the i The effective value of the fundamental voltage output of each channel inverter U i , No. i The effective value of the fundamental current on the primary coil of each channel I i , No. i The phase difference between the fundamental voltage and fundamental current of the inverter output of each channel φ i and the rest n -2 channels of inverter input DC voltage, the first k The inverter input DC voltage of each channel is recorded as , k ≠ i ;

[0072] S103, according to U i , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden , No. i Mutual inductance identification value of each channel M i_iden , No. i Identification value of the rectifier output voltage of each channel U oi_iden and i Identification value of rectifier output current of each channel I oi_iden ;

[0073] S104, I oi_iden Equivalent to k Identification value of rectifier output current of each channel I ok_iden ,according to and U oi_iden Calculate the k Identification value of rectifier output current of each channel U ok_iden ,according to I ok_iden and U ok_iden Calculate thek Equivalent load identification value of each channel , No. k Mutual inductance identification value of each channel M k_iden and total system load .

[0074] The method is described below in detail by taking an ISOS-IPT system using an SS compensation network as an example. However, the parameter identification method and device of the multi-channel ISOS-IPT system can also be applied to ISOS-IPT systems with other compensation networks.

[0075] (1) Overall framework and working principle

[0076] like Figure 1 As shown in FIG. 1 , the primary circuit includes an inverter, a primary compensation network and a primary coil, and the secondary circuit includes a secondary coil, a secondary compensation network and a rectifier. The inverter of each IPT channel includes four switch tubes. T 1. T 2. T 3. T 4. The inverter of each IPT channel includes four diodes D 1. D 2. D 3. D 4. Each IPT channel uses an SS compensation network. The primary side compensation network of each channel includes a primary side series compensation capacitor and a primary side parasitic resistor. The secondary side compensation network of each channel includes a secondary side series compensation capacitor and a secondary side parasitic resistor. The SS compensation network has a simple structure and uses fewer components. Building an ISOS multi-channel IPT system based on this can effectively reduce the overall complexity of the system and improve the system's service life. In the figure, C fi Indicates i The filter capacitors for each channel, R Li Indicates i The equivalent load of each channel is I rec Indicates i The secondary fundamental current of each channel, U in represents the total system input, U out Indicates the total system output.

[0077] For i For each channel, the equivalent circuit diagram is as follows: Figure 2 shown.

[0078] The working principle of the present invention is as follows: First, the voltage sensor measures thei Fundamental RMS value of the primary inverter output voltage of each channel U i , the current sensor measures the i The effective value of the fundamental current on the primary coil of each channel I i , and measure the i The phase difference between the fundamental voltage and fundamental current of the inverter output of each channel φ i , and then calculate the i Channel primary side reflection impedance Z ri The real part Re[ Z ri ] and Im[ Z ri ], thus obtaining i Equivalent load identification value of the channel R Li_iden , rectifier equivalent load identification value R eqi_iden And the inductance identification value of the equivalent load X eqi_iden , and then calculate the i Mutual inductance identification value of the channel M i_iden , Rectifier input voltage identification value U reci_iden , Rectifier output voltage identification value U oi_iden And rectifier output current identification value I oi_iden Secondly, combining the topology and transmission characteristics of the ISOS system, when measuring any ( n -2) Inverter input voltage of each channel U dk Under the premise of k Rectifier output voltage identification value of each channel U ok_iden , Rectifier output current identification value I ok_iden and rectifier input voltage identification value U reck_iden , and then get the k Equivalent load identification value of each channel R Lk_iden and mutual inductance identification value M k_iden .

[0079] (2) No. i Channel parameter identification

[0080] The basis Ui , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden Includes steps:

[0081] The first i The equivalent load of the rectifier of each channel is regarded as a resistive-inductive load, and the i The resistance of the equivalent load of the channel rectifier The expression of inductance The expression and i Channel primary side reflection impedance Z ri Expression of

[0082] according to U i , I i and φ i calculate Z ri the values ​​of the real and imaginary parts, and Z ri Ratio coefficient of real part to imaginary part ;

[0083] according to The expression of inductance The expression is determined R Li_iden about The expression of Calculation of the value R Li_iden .

[0084] No. i Mutual inductance identification value of each channel M i_iden The calculation steps include:

[0085] according to R Li_iden Calculation of the value Identification value R eqi_iden and Identification value X eqi_iden ;

[0086] according to R eqi_iden , X eqi_iden , Z riCalculation of the real and imaginary values M i_iden .

[0087] U oi_iden and I oi_iden The calculation includes the following steps: Determine the first i The transfer function of the rectifier input voltage and the inverter output voltage is G ui Expression of

[0088] according to R eqi_iden , X eqi_iden , M i_iden as well as G ui The expression calculation of G ui The value of

[0089] according to U i The measured values ​​and G ui The calculated value of i Identification value of channel secondary voltage U reci_iden ;

[0090] according to U reci_iden calculate U oi_iden and I oi_iden .

[0091] Depend on Figure 2 According to Kirchhoff's law,

[0092] (1)

[0093] In the formula, Indicates i Each channel inverter outputs the fundamental voltage phasor, Indicates i Each channel inverter outputs the fundamental current phasor, Indicates i The fundamental AC current phasor of the secondary side of each channel, Z pi For the i The primary side impedance of each channel is Indicates i The mutual inductance of each channel, Z si For the iThe secondary side impedance of each channel is Z eqi For the i The equivalent impedance of the rectifier load of each channel is: is the inverter operating angular frequency, and j represents an imaginary unit.

[0094] (2)

[0095] In the formula, Indicates i The self-inductance of the primary coil of each channel, Indicates i The primary side series compensation capacitor of each channel, Indicates i The primary side parasitic resistance of each channel, Indicates i The secondary coil self-inductance of each channel, Indicates i The secondary side series compensation capacitor of each channel, Indicates i The secondary side parasitic resistance of each channel.

[0096] Consider the rectifier load as a resistive-inductive load rather than a purely resistive load. The expression for the resistive-inductive load is as follows:

[0097] (3)

[0098] in, Indicates i The resistive part of the rectifier equivalent impedance of each channel, Indicates i Channel equivalent load, Indicates i The reactance part of the rectifier equivalent impedance of each channel, .

[0099] It can be calculated that i Reflection impedance of each channel Z ri The expression is

[0100] (4)

[0101] In the formula, Indicates i The secondary reactance of each channel.

[0102] Measurement i The effective value of the inverter output voltage and current of each channel U i , I i, and the phase difference φ i , then

[0103] (5)

[0104] In the formula, Re[ Z ri ] is the reflected impedance Z ri The real part of Im[ Z ri ] is the reflected impedance Z ri The imaginary part of i When the secondary side of each channel resonates,

[0105] (6)

[0106] From formula (3), we can get

[0107] (7)

[0108] In the formula, R Li_iden For the i The identification value of the channel equivalent load, that is, The identification value of , then

[0109] (8)

[0110] In the formula, , , They are all auxiliary calculation symbols and have no actual physical meaning. R eqi_iden and X eqi_iden For the i The identification values ​​of resistance and reactance in the equivalent impedance of the channel rectifier, that is, and identification value.

[0111] From formula (5), we can get

[0112] (9)

[0113] In the formula, M i_iden For the i The identification value of channel mutual inductance is The identification value of

[0114] (10)

[0115] In the formula, Indicates i Fundamental current phasor of the secondary side of the channel, Indicates i Channel secondary side fundamental voltage phasor, Indicates i The channel rectifier load equivalent impedance, and

[0116] (11)

[0117] Available

[0118] (12)

[0119] In the formula, Indicates i The mutual inductance of the channel i The fundamental effective value of the AC voltage on the secondary side of each channel, Indicates i Channel primary side compensation reactance value, G ui For the i The transfer function of the channel rectifier input voltage and inverter output voltage. So,

[0120] (13)

[0121] In the formula, U reci_iden For the i Identification value of the channel secondary voltage, U oi_iden For the i Identification value of channel rectifier output voltage, I oi_iden For the i Identification value of the channel rectifier output current.

[0122] In the existing single-channel IPT system parameter identification method, it is usually necessary to change the system operating frequency during the identification process, which is likely to affect the system transmission efficiency, and the high-frequency change of the system resonance frequency will affect the stability of the system operation. i When determining the parameters of a channel, it is only necessary to identify it at the normal working frequency, which greatly improves the applicability of the method.

[0123] (3) Identification of other channel parameters

[0124] For the other ( n -1) channels, measure any ( n -2) The inverter input voltage of each channel, given the total input voltage of the system U inIn the case of n -1) channel inverter input voltage.

[0125] Because the system is connected in series on the DC side of the primary and secondary sides, the following variable relationship exists:

[0126] (14)

[0127] (15)

[0128] In the formula, Indicates i The inverter input DC current of the channel, Indicates k The inverter input DC current of the channel, Indicates i The rectifier outputs a DC current. Indicates k The rectifier outputs a DC current. Indicates i The rectifier outputs a DC voltage of the channel, Indicates i The inverter input DC voltage of the channel, Indicates the DC current output by the power supply. Indicates the DC current on the load side, Indicates the DC voltage on the load side, Indicates the power supply output DC voltage, Indicates k The rectifier outputs a DC voltage of the channel, Indicates k Inverter input DC voltage for the channel.

[0129] Also because

[0130] (16)

[0131] From equation (14) and equation (15), we can get

[0132] (17)

[0133] In the formula, U ok_iden and I ok_iden Respectively k The identification values ​​of the rectifier output voltage and current of each channel are and The identification value of U oi_iden and I oi_idenRespectively i The identification values ​​of the rectifier output voltage and current of each channel are and The identification value of Indicates k The identification value of the secondary voltage fundamental effective value of each channel, that is, Therefore, k The equivalent load of each channel and the equivalent impedance of the rectifier are:

[0134] (18)

[0135] In the formula, Indicates k The identification value of the equivalent load of each channel is The identification value of R eqk_iden and X eqk_iden Respectively k The identification values ​​of resistance and reactance in the equivalent impedance of the channel rectifier, that is, and The identification value of Indicates k The secondary side series compensation capacitor of each channel is based on

[0136] (19)

[0137] For the k The secondary coil self-inductance of each channel, No. k The secondary side series compensation capacitor of each channel.

[0138] Therefore, the k Secondary current identification value of each channel for

[0139] (20)

[0140] Also because

[0141] (twenty one)

[0142] In the formula, Indicates k The inverter output fundamental voltage effective value of each channel, Indicates k The primary compensation network impedance of each channel, Indicates k The secondary compensation network impedance of each channel, Indicates kIdentification value of the rectifier load equivalent impedance of each channel, Indicates k The primary side parasitic resistance of each channel, Indicates k The primary compensation network reactance of each channel, Indicates k The secondary side parasitic resistance of each channel, Indicates k The secondary compensation network reactance of each channel, M k_iden For the k The identification value of the mutual inductance of each channel is M k The identification value of

[0143] (twenty two)

[0144] make

[0145] (twenty three)

[0146] The first j The mutual inductance identification value of each channel is

[0147] (twenty four)

[0148] Therefore, the actual system load The identification value is

[0149] (25)

[0150] In the formula, U ok_iden For the k The identified value of the rectifier output voltage of each channel.

[0151] (4) Specific process of parameter identification method

[0152] A parameter identification method for a multi-channel ISOS-IPT system according to an embodiment of the present invention has the following process: Figure 3 shown.

[0153] The first step is to measure i The effective value of the inverter output voltage and current of each channel U i , I i , and the phase difference φ i , calculate the primary side reflection impedance based on the compensation network parameters Z ri, and calculate the coefficient based on the relationship between the imaginary and real parts of the reflected impedance and the rectifier equivalent impedance α i ,get R Li_iden ;

[0154] The second step is to determine the R Li_iden ,calculate R eqi_iden and X eqi_iden , combined with formula (9), calculate M i_iden ;

[0155] The third step is to measure any other n -2) channels of inverter input DC voltage, combined with the total system input voltage, the remaining ( n -2) The effective value of the inverter output voltage of each channel U dk ;

[0156] The fourth step is to calculate the identification result according to formula (17): R Lk_iden , R eqk_iden , X eqk_iden ;

[0157] Step 5: According to equations (20) to (24), the identification results are calculated. M i_iden .

[0158] Step 6: According to formula (25), the identification result is calculated R iden .

[0159] According to a second aspect of the present invention, a parameter identification device for a multi-channel ISOS-IPT system is provided, wherein the multi-channel ISOS-IPT system comprises n IPT channels, n ≥2, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier, and the parameter identification device includes the steps of:

[0160] The control module is used to adjust the system circuit parameters. i The secondary side circuit of each channel is in resonance. i The primary side circuit of each channel is in ZVS state;

[0161] The measurement module is used to obtain the total input voltage of the system and measure the i Channel inverter output voltage U i , No. i The effective value of the fundamental current on the primary coil of each channel I i , No. i The phase difference between the fundamental voltage and fundamental current of the inverter output of each channel φ i and the rest n -2 channels of inverter input DC voltage, the first k The inverter input DC voltage of each channel is recorded as , k ≠ i ;

[0162] Identification module, used to U i , I i and φ i Calculate the i Equivalent load identification value of each channel R Li_iden , No. i Mutual inductance identification value of each channel M i_iden , No. i Identification value of the rectifier output voltage of each channel U oi_iden and i Identification value of rectifier output current of each channel I oi_iden , also used to I oi_iden Equivalent to k Identification value of rectifier output current of each channel I ok_iden ,according to and U oi_iden Calculate the k Identification value of rectifier output current of each channel U ok_iden ,according to I ok_iden and U ok_iden Calculate the k Equivalent load identification value of each channel , No. k Mutual inductance identification value of each channel M k_iden and total system load .

[0163] The implementation principle and technical effect of the parameter identification device are the same as those of the above-mentioned parameter identification method, and will not be repeated here.

[0164] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A parameter identification method for a multi-channel ISOS-IPT system, characterized in that: The multi-channel ISOS-IPT system includes n IPT channels, n≥2, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier, and the parameter identification method includes the steps of: Adjust the system circuit parameters so that the secondary side circuit of the i-th channel is in a resonant state and the primary side circuit of the i-th channel is in a ZVS state; Get the total input voltage of the system and measure the effective value of the fundamental voltage output of the inverter of the i-th channel U i , the effective value of the fundamental current on the primary side coil of the i-th channel I i , the phase difference between the fundamental voltage and fundamental current output by the ith channel inverter and the inverter input DC voltages of the remaining n-2 channels, and the inverter input DC voltage of the kth channel is recorded as U dk , k≠i; According to U i ,I i and Calculate the equivalent load identification value R of the i-th channel Li_iden , the mutual inductance identification value M of the i-th channel i_iden , the identification value U of the rectifier output voltage of the i-th channel oi_iden and the identified value I of the rectifier output current of the i-th channel oi_iden ; Will I oi_iden Equivalent to the identified value I of the rectifier output current of the kth channel ok_iden , according to U dk and U oi_iden Calculate the identification value U of the rectifier output current of the kth channel ok_iden , according to I ok_iden and U ok_iden Calculate the equivalent load identification value R of the kth channel Lk_iden , the mutual inductance identification value M of the kth channel k_iden and the total system load R iden ; According to U i ,I i and Calculate the equivalent load identification value R of the i-th channel Li_iden Includes steps: Consider the equivalent load of the rectifier of the i-th channel as a resistive-inductive load and determine the resistance R of the equivalent load of the rectifier of the i-th channel eqi The expression of inductance X eqi The expression of the primary side reflection impedance Z of the i-th channel ri Expression of According to U i ,I i and Calculate Z ri The values ​​of the real and imaginary parts, and Z ri The ratio coefficient of the real part to the imaginary part is α i ; According to R eqi The expression of inductance X eqi The expression for determining R Li_iden About α i The expression of α i Calculate the value of R Li_iden ; The mutual inductance identification value M of the i-th channel i_iden The calculation steps include: According to R Li_iden Calculate the value of R eqi The identification value R eqi_iden and X eqi The identification value X eqi_iden ; According to R eqi_iden , X eqi_iden , Z ri The values ​​of the real and imaginary parts are calculated as M i_iden ; U oi_iden and I oi_iden The calculation includes the following steps: Determine the transfer function G of the rectifier input voltage and inverter output voltage of the i-th channel according to the circuit parameters ui Expression of According to R eqi_iden , X eqi_iden 、M i_iden and G ui The expression for calculating G ui The value of According to U i The measured value and G ui Calculate the identification value U of the secondary voltage of the i-th channel reci_iden ; According to U reci_iden Calculate U oi_iden and I oi_iden .

2. A parameter identification method for a multi-channel ISOS-IPT system as claimed in claim 1, characterized in that: Where U di Represents the inverter DC input voltage of the i-th channel.

3. A parameter identification method for a multi-channel ISOS-IPT system as claimed in claim 1, characterized in that: The mutual inductance identification value M of the kth channel k_iden The calculation includes the following steps: Consider the equivalent load of the k-th channel rectifier as a resistive-inductive load, according to R Lk_iden Calculate the identification value R of the resistance of the equivalent load of the k-channel rectifier eqk_iden And the identification value of inductance X eqk_iden ; Calculate the secondary current identification value I of the kth channel reck_iden ; According to R eqk_iden , X eqk_iden and I reck_iden Calculate M k_iden .

4. A parameter identification method for a multi-channel ISOS-IPT system as claimed in claim 1, characterized in that: Each IPT channel uses an SS compensation network. The primary side compensation network of each channel includes a primary side series compensation capacitor and a primary side parasitic resistor. The secondary side compensation network of each channel includes a secondary side series compensation capacitor and a secondary side parasitic resistor. Li_iden The calculation formula is: Where, L si represents the self-inductance of the secondary coil of the ith channel, C si represents the secondary side series compensation capacitor of the ith channel, Re[Z ri ] represents Z ri The real part of Im[Z ri ] represents Z ri The imaginary part, L pi represents the self-inductance of the primary coil of the ith channel, C pi Represents the primary series compensation capacitor of the ith channel, R pi represents the primary side parasitic resistance of the ith channel, ω is the inverter operating angular frequency; M i_iden The calculation formula is: In the formula, R si represents the parasitic resistance of the secondary side of the i-th channel; U oi_iden and I oi_iden The calculation formula is: In the formula, α i , β i , D i They are all auxiliary calculation symbols.

5. A parameter identification method for a multi-channel ISOS-IPT system as claimed in claim 3, characterized in that: Each IPT channel uses an SS compensation network. The primary side compensation network of each channel includes a primary side series compensation capacitor and a primary side parasitic resistor. The secondary side compensation network of each channel includes a secondary side series compensation capacitor and a secondary side parasitic resistor. k_iden The calculation formula is: Where U k represents the effective value of the fundamental voltage output by the kth channel inverter, R pk Represents the primary side parasitic resistance of the kth channel, R sk represents the secondary side parasitic resistance of the kth channel, X pk represents the primary side reactance of the kth channel, X sk represents the secondary side reactance of the kth channel, c k 、c k1 、c k2 They are all auxiliary calculation symbols, and ω is the operating angular frequency of the inverter.

6. A parameter identification device for a multi-channel ISOS-IPT system, characterized in that: The multi-channel ISOS-IPT system includes n IPT channels, n≥2, the input of each IPT channel is connected in series, the output of each IPT channel is connected in series, each IPT channel includes a primary side circuit and a secondary side circuit, the primary side circuit includes an inverter, a primary side compensation network and a primary side coil, the secondary side circuit includes a secondary side coil, a secondary side compensation network and a rectifier, and the parameter identification device includes: A control module is used to adjust system circuit parameters so that the secondary side circuit of the i-th channel is in a resonant state and the primary side circuit of the i-th channel is in a ZVS state; The measurement module is used to obtain the total input voltage of the system and measure the effective value U of the fundamental voltage output of the inverter of the i-th channel. i , the effective value of the fundamental current on the primary side coil of the i-th channel I i , the phase difference between the fundamental voltage and fundamental current output by the ith channel inverter and the inverter input DC voltages of the remaining n-2 channels, and the inverter input DC voltage of the kth channel is recorded as U dk , k≠i; Identification module, used to identify i ,I i and Calculate the equivalent load identification value R of the i-th channel Li_iden , the mutual inductance identification value M of the i-th channel i_iden , the identification value U of the rectifier output voltage of the i-th channel oi_iden and the identified value I of the rectifier output current of the i-th channel oi_iden , also used to convert I oi_iden Equivalent to the identified value I of the rectifier output current of the kth channel ok_iden , according to U dk and U oi_iden Calculate the identification value U of the rectifier output current of the kth channel ok_iden , according to I ok_iden and U ok_iden Calculate the equivalent load identification value R of the kth channel Lkiden , the mutual inductance identification value M of the kth channel k_iden and the total system load R iden ; According to U i ,I i and Calculate the equivalent load identification value R of the i-th channel Li_iden Includes steps: Consider the equivalent load of the rectifier of the i-th channel as a resistive-inductive load and determine the resistance R of the equivalent load of the rectifier of the i-th channel eqi The expression of inductance X eqi The expression of the primary side reflection impedance Z of the i-th channel ri Expression of According to U i ,I i and Calculate Z ri The values ​​of the real and imaginary parts, and Z ri The ratio coefficient of the real part to the imaginary part is α i ; According to R eqi The expression of inductance X eqi The expression for determining R Li_iden About α i The expression of α i Calculate the value of R Li_iden ; The mutual inductance identification value M of the i-th channel i_iden The calculation steps include: According to R Li_iden Calculate the value of R eqi The identification value R eqi_iden and X eqi The identification value X eqi_iden ; According to R eqi_iden , X eqi_iden , Z ri The values ​​of the real and imaginary parts are calculated as M i_iden ; U oi_iden and I oi_iden The calculation includes the following steps: Determine the transfer function G of the rectifier input voltage and inverter output voltage of the i-th channel according to the circuit parameters ui Expression of According to R eqi_iden , X eqi_iden 、M i_iden and G ui The expression for calculating G ui The value of According to U i The measured value and G ui Calculate the identification value U of the secondary voltage of the i-th channel reci_iden ; According to U reci_iden Calculate U oi_iden and I oi_iden .

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