Isolated switching power supply transformer loss test circuit and equipment

Abstract

The invention relates to a loss test circuit and equipment for an isolated switching power supply transformer. The circuit comprises: a primary circuit with variable topology and parameters outputs a primary voltage, a primary current sampling signal and two bridge arm voltage sampling signals; a secondary circuit with variable topology and parameters outputs a secondary voltage and a secondary current sampling signal; a primary-side variable topology variable parameter and power measurement circuit selects a primary voltage and a primary current signal of an external transformer under test according to the sampled bridge arm voltage signal and performs segmented integration to obtain a primary power signal; a secondary-side variable topology variable parameter and power measurement circuit selects a secondary voltage and a secondary current signal of an external transformer under test according to the sampled bridge arm voltage signal and performs segmented integration to obtain a secondary power signal; a control test module is used to collect power measurement results. The circuit simulates the real working condition of the isolated switching power supply transformer, adapts to various isolated power supply topologies and their specific parameters, and provides a guarantee for power online test calculation.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, and in particular to an isolated switching power supply transformer loss test circuit and equipment. Background Art

[0002] Isolated switching power supplies continue to develop towards high power density. The loss of its transformer accounts for a large proportion of the power loss and is one of the main factors restricting the improvement of the power density of isolated switching power supplies. The loss test of the isolated switching power supply transformer has important guiding significance and reference value for its design improvement.

[0003] The traditional thermal indirect test method cannot measure the transformer loss alone or has low accuracy. The loss calculation of the transformer electrical quantity is restricted by multiple factors, making it difficult to take into account both the range and accuracy. The current design of high power density power supplies usually only uses estimates, but this estimation method lacks actual measured data for comparison, and the voltage and current of the isolated switching power supply transformer are usually not sinusoidal. The core loss curve estimates the magnetic loss and the Dowell method estimates the copper loss, which are difficult to test.

[0004] Therefore, a circuit is needed to accurately test the transformer loss of an isolated switching power supply according to its actual topology and working conditions. Summary of the invention

[0005] Based on this, it is necessary to provide an isolated switching power supply transformer loss test circuit that can accurately test the transformer loss of the isolated switching power supply according to the actual topology and working conditions of the isolated switching power supply.

[0006] In a first aspect, the present application provides an isolated switching power supply transformer loss test circuit, the circuit comprising:

[0007] The primary circuit with variable topology and parameters is used to simulate the primary circuit topology and parameters of the external transformer under test, and output the primary voltage sampling signal, primary current sampling signal and two-bridge arm voltage sampling signal of the external transformer under test in two ranges;

[0008] The secondary circuit with variable topology and parameters is used to simulate the secondary circuit topology and parameters of the external transformer under test, and output the secondary voltage sampling signal and the secondary current sampling signal of the external transformer under test in two ranges;

[0009] The primary side variable topology variable parameter and power measurement circuit is connected with the primary side circuit with variable topology and parameters and the control test module, and is used to change the structure and parameters of the primary side circuit with variable topology and parameters, and select the primary side voltage signal and the primary side current signal of the external transformer under test of different ranges for segmented integration according to the sampled bridge arm voltage signal, so as to obtain the primary side power signal;

[0010] The secondary side variable topology variable parameter and power measurement circuit is connected with the topology and parameter variable secondary side circuit and the control test module, and is used to change the structure and parameters of the topology and parameter variable secondary side circuit, and select the secondary side voltage signal and the secondary side current signal of the external transformer under test of different ranges for segmented integration according to the sampled bridge arm voltage signal, so as to obtain the secondary side power signal;

[0011] The control test module is used to control the connected primary circuit with variable topology and parameters, the secondary circuit with variable topology and parameters, the primary circuit with variable topology and parameters and power measurement circuit, and the secondary circuit with variable topology and parameters and power measurement circuit, and to collect the primary power signal of the primary circuit with variable topology and parameters and power measurement circuit and the secondary power signal of the secondary circuit with variable topology and parameters and power measurement circuit.

[0012] In one embodiment, the topology and parameter variable primary circuit includes a variable parameter DC input interface, a topology and parameter variable primary bridge arm, a short-circuitable resonant interface, a small-range adjustable same-delay primary current sampling circuit, a large-range adjustable same-delay primary current sampling circuit, a small-range adjustable same-delay primary voltage sampling circuit, a large-range adjustable same-delay primary voltage flow sampling circuit, a same-delay first bridge arm voltage sampling circuit, a primary low parasitic parameter bridge arm lead-out terminal and a primary low parasitic parameter bridge arm lead-out terminal; wherein:

[0013] The variable parameter DC input interface is connected to the external input DC voltage and the primary bridge arm with variable topology and parameters; the primary bridge arm with variable topology and parameters is connected to the short-circuited resonant interface, the small-scale adjustable same-delay primary voltage sampling circuit, the same-delay first bridge arm voltage sampling circuit, the same-delay second bridge arm voltage sampling circuit, the primary low parasitic parameter bridge arm lead-out terminal, the primary variable topology variable parameter and power measurement circuit; the short-circuited resonant interface is connected to the external resonant inductor, the small-scale adjustable same-delay primary current sampling circuit, the small-scale adjustable same-delay primary voltage sampling circuit, the large-scale adjustable same-delay primary voltage flow sampling circuit, and the same-delay first bridge arm voltage sampling circuit; the small-scale adjustable same-delay primary current sampling circuit is connected to the large-scale adjustable same-delay primary current sampling circuit. The large-scale adjustable same-delay primary current sampling circuit is connected to the primary low parasitic parameter bridge arm lead-out terminal for outputting a large-scale sampled primary current; the small-scale adjustable same-delay primary voltage sampling circuit is connected to the same-delay second bridge arm voltage sampling circuit and the primary low parasitic parameter bridge arm lead-out terminal for outputting a small-scale sampled primary voltage; the large-scale adjustable same-delay primary voltage current sampling circuit is used to output a large-scale sampled primary voltage; the same-delay first bridge arm voltage sampling circuit is used to output the first bridge arm sampling voltage; the same-delay second bridge arm voltage sampling circuit is connected to the primary low parasitic parameter bridge arm lead-out terminal for outputting the second bridge arm sampling voltage; the primary low parasitic parameter bridge arm lead-out terminal is connected to the external transformer under test.

[0014] In one of the embodiments, the first target current flows out from the short-circuited resonant interface, passes through a small-range adjustable same-delay primary current sampling circuit, a large-range adjustable same-delay primary current sampling circuit, and a primary low parasitic parameter bridge arm lead-out terminal to reach the external transformer under test, and then flows out from the external transformer under test through the primary low parasitic parameter bridge arm lead-out terminal, the same-delay second bridge arm voltage sampling circuit, a small-range adjustable same-delay primary voltage sampling circuit, and a primary bridge arm with variable topology and parameters.

[0015] In one embodiment, the topology and parameter variable secondary circuit includes a secondary low parasitic parameter rectifier input terminal, a topology and parameter variable rectifier circuit, a short-circuit filter inductor interface and a current sampling circuit, a load interface and an output voltage sampling circuit, a small-range adjustable simultaneous delay secondary voltage sampling circuit, a large-range adjustable simultaneous delay secondary voltage sampling circuit, a small-range adjustable simultaneous delay secondary current sampling circuit and a large-range adjustable simultaneous delay secondary current sampling circuit; wherein:

[0016] The secondary side low parasitic parameter rectifier introduction terminal is connected to the external measured transformer, the topology and parameter variable rectifier circuit, the small-scale adjustable delay secondary side voltage sampling circuit, the large-scale adjustable delay secondary side voltage sampling circuit, and the large-scale adjustable delay secondary side current sampling circuit; the topology and parameter variable rectifier circuit is connected to the short-circuit filter inductor interface and current sampling circuit, the load interface and output voltage sampling circuit, the small-scale adjustable delay secondary side voltage sampling circuit, the large-scale adjustable delay secondary side voltage sampling circuit, the small-scale adjustable delay secondary side current sampling circuit, the secondary side variable topology parameter and power measurement circuit; the short-circuit filter inductor interface and current sampling circuit are connected to the external filter inductor The load interface and the output voltage sampling circuit are connected to the external load; the small-scale adjustable delay secondary voltage sampling circuit is connected to the large-scale adjustable delay secondary voltage sampling circuit and the large-scale adjustable delay secondary current sampling circuit, and is used to output the small-scale sampled secondary voltage; the large-scale adjustable delay secondary voltage sampling circuit is connected to the large-scale adjustable delay secondary current sampling circuit, and is used to output the large-scale sampled secondary voltage; the small-scale adjustable delay secondary current sampling circuit is connected to the large-scale adjustable delay secondary current sampling circuit, and is used to output the small-scale sampled secondary current; the large-scale adjustable delay secondary current sampling circuit is used to output the large-scale sampled secondary current.

[0017] In one of the embodiments, the second target current flows out from the topology and parameter variable rectifier circuit, passes through a small-range adjustable and delayed secondary current sampling circuit, a large-range adjustable and delayed secondary current sampling circuit, and a secondary low parasitic parameter rectifier introduction terminal respectively; the third target current flows out from the topology and parameter variable rectifier circuit, passes through a load interface and an output voltage sampling circuit to reach an external load, and returns to the topology and parameter variable rectifier circuit through the load interface and the output voltage sampling circuit.

[0018] In one embodiment, the primary side transformer topology parameter and power measurement circuit includes a bridge arm power tube drive circuit, a primary side topology switch drive circuit and a transformer primary side power segmented integration circuit based on the power supply mode; wherein:

[0019] The bridge arm power tube drive circuit and the primary side topology switching switch drive circuit are connected to the primary side bridge arm with variable topology and parameters; the transformer primary side power segmented integration circuit based on the power supply mode is used to integrate the small-scale sampling primary side current, large-scale sampling primary side current, small-scale sampling primary side voltage, large-scale sampling primary side voltage, first bridge arm sampling voltage, and second bridge arm sampling voltage in the primary side circuit with variable topology and parameters.

[0020] In one embodiment, the secondary side topology variable parameter and power measurement circuit includes a rectifier tube synchronous rectification optional drive circuit, a secondary side topology switching switch drive circuit and a transformer secondary side power segmented integration circuit based on the power supply mode; wherein:

[0021] The rectifier tube synchronous rectification optional drive circuit and the secondary side topology switching switch drive circuit are connected to the topology and parameter variable rectification circuit; the transformer secondary side power segmented integration circuit based on the power supply mode is used to integrate the first bridge arm sampling voltage, the second bridge arm sampling voltage, the small-scale sampling secondary side voltage, the large-scale sampling secondary side voltage, the small-scale sampling secondary side current, and the large-scale sampling secondary side current in the topology and parameter variable primary circuit and the topology and parameter variable secondary circuit.

[0022] In a second aspect, the present application further provides an isolated switching power supply transformer loss test device, including the isolated switching power supply transformer loss test circuit provided in the first aspect.

[0023] The above-mentioned isolated switching power supply transformer loss test circuit, by changing the topology and parameters of the primary circuit and the topology and parameters of the secondary circuit, makes the system composed of the primary circuit, the secondary circuit and the external transformer under test and the peripheral circuit similar to the actual working power supply structure and parameters of the external transformer under test, and can simulate the actual working conditions of the external transformer under test and perform online testing on its loss. Since the sampling delays of voltage and current are the same, the accuracy of power calculation can be improved; at the same time, the dual-range sampling of the transformer voltage and current and the segmented integration according to the circuit working mode can obtain more accurate transformer primary and secondary power calculation values. This application can not only solve the problem that the loss of the isolated switching power supply transformer is difficult to measure accurately, but also can be applied to transformer loss tests of various types of isolated switching power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The overall block diagram of an isolated switching power supply transformer loss test circuit according to an embodiment;

[0025] Figure 2 This is a working principle diagram of an isolated switching power supply transformer loss test circuit simulating various types of isolated switching power supply primary circuits in one embodiment;

[0026] Figure 3 A schematic diagram of a primary circuit of a single-tube flyback of an isolated switching power supply and a schematic diagram of a primary circuit of a single-tube forward of an isolated switching power supply according to an embodiment;

[0027] Figure 4 A schematic diagram of a primary circuit of a double-tube flyback of an isolated switching power supply and a schematic diagram of a primary circuit of a double-tube forward of an isolated switching power supply according to an embodiment;

[0028] Figure 5 A schematic diagram of a primary circuit of an isolated switching power supply active clamped forward according to an embodiment;

[0029] Figure 6 A schematic diagram of a primary circuit of an isolated switching power supply full-bridge circuit according to an embodiment;

[0030] Figure 7 A schematic diagram of a primary circuit of an isolated switching power supply half-bridge circuit according to an embodiment;

[0031] Figure 8 A schematic diagram of a primary circuit of an isolated switching power supply LLC according to an embodiment;

[0032] Fig. 9 A schematic diagram of the working principle of an isolated switching power supply transformer loss test circuit simulating various types of isolated switching power supply secondary circuits according to an embodiment;

[0033] Fig.10 A schematic diagram of a secondary circuit of a half-wave rectifier of an isolated switching power supply according to an embodiment;

[0034] Fig.11 A schematic diagram of a secondary circuit of a full-wave rectifier of an isolated switching power supply according to an embodiment;

[0035] Fig.12 A schematic diagram of a secondary circuit of an isolated switching power supply full-bridge rectifier according to an embodiment;

[0036] Fig.13 A schematic diagram of a current sampling circuit module in an isolated switching power supply transformer loss test circuit according to an embodiment;

[0037] Fig.14 A schematic diagram of a voltage sampling circuit module in an isolated switching power supply transformer loss test circuit according to an embodiment;

[0038] Fig.15A schematic diagram of a voltage judgment circuit in an isolated switching power supply transformer loss test circuit according to an embodiment;

[0039] Fig.16 A schematic diagram of a current judgment circuit in an isolated switching power supply transformer loss test circuit according to an embodiment;

[0040] Fig.17 The invention is a schematic diagram of a segmented integration circuit based on power supply mode in an isolated switching power supply transformer loss test circuit in an isolated switching power supply transformer loss test circuit according to an embodiment. DETAILED DESCRIPTION

[0041] Isolated switching power supplies continue to develop towards high power density. The loss of isolated switching power supply transformers accounts for a large proportion of power loss and is one of the main factors restricting the improvement of isolated switching power supply power density. The loss test of isolated switching power supply transformers has important guiding significance and reference value for its design improvement.

[0042] The thermal indirect test method cannot measure the transformer loss alone or the accuracy is not high. The calculation of the transformer loss is subject to the following factors: First, the appropriate topology of the isolated switching power supply will change according to the application scenario. The working state of the magnetic components in different topologies is different. The transformer loss is suitable for online testing under the working state of the power supply, but it is difficult to test the electrical quantity of the high power density power supply online; second, the traditional voltage and current sampling delay time is different; third, due to the switching working state of the power supply, its electrical quantity switches between high voltage and high current and zero, and there is a contradiction between the range and the accuracy of the small voltage and small current test.

[0043] The current design of high power density power supply usually only estimates, that is, the core loss is estimated based on the manufacturer's core loss curve and switching frequency, and the copper loss is estimated based on the Dowell method. However, the above estimates lack actual measured data for comparison, and the voltage and current of the isolated switching power supply transformer are usually not sinusoidal. The core loss curve estimates of magnetic loss and the Dowell method estimates of copper loss have errors that are difficult to test.

[0044] In summary, there is currently a lack of a method and an implementation circuit that can accurately test the transformer loss of an isolated switching power supply according to its actual topology and operating conditions.

[0045] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The drawings provide embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein.

[0046] The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0047] It is to be understood that the terms "first", "second" etc. used in the present application can be used to describe various elements in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. "Connection" in the following embodiments, if the connected circuits, modules, units, etc. have the transmission of electric signals or data each other, should be understood as "electrical connection", "communication connection", etc. The singular forms of "one", "one" and "said / the" can also include plural forms, unless the context clearly indicates another way. The terms "include / comprise" or "have" etc. specify the existence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of existing or adding one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0048] In an exemplary embodiment, the isolated switching power supply transformer loss test circuit is as follows: Figure 1 As shown, it includes: a primary circuit 100 with variable topology and parameters, a secondary circuit 200 with variable topology and parameters, a primary circuit 300 with variable topology and parameters and power measurement, a secondary circuit 400 with variable topology and parameters and power measurement, and a control test module 500.

[0049] Specifically, the primary circuit 100 with variable topology and parameters is connected to external electrical equipment, which includes an external transformer under test, an external input DC voltage, and an external resonant inductor. It is used to simulate the primary circuit topology structure and parameters of the isolated switching power supply in which the external transformer under test works, and outputs two ranges of primary voltage sampling signals and primary current sampling signals of the external transformer under test, and outputs two bridge arm voltage sampling signals, wherein the output sampling signals have the same delay relative to the actual electrical quantities of the sampled circuit.

[0050] Specifically, the secondary circuit 200 with variable topology and parameters is connected to external electrical equipment, which includes an external transformer under test, an external load, and an external filter inductor. It is used to simulate the secondary circuit topology structure and parameters of the isolated switching power supply in which the external transformer under test works, and output two ranges of secondary voltage sampling signals and secondary current sampling signals of the external transformer under test. The output sampling signals have the same delay relative to the actual electrical quantities of the sampled circuit.

[0051] Specifically, the primary side variable topology parameter and power measurement circuit 300 is connected to the topology and parameter variable primary bridge arm and the control test module 500 in the topology and parameter variable primary circuit 100, and is used to change the structure and parameters of the topology and parameter variable primary circuit 100 by comparing with the actual primary circuit of the isolated switching power supply in which the simulated external transformer under test works; drive the primary bridge arm power tube in the topology and parameter variable primary circuit 100 by comparing with the actual working condition of the isolated switching power supply in which the simulated external transformer under test works; and select the primary voltage signal and primary current signal of the external transformer under test of different ranges for segmented integration according to the collected bridge arm voltage signal to obtain an accurate primary power signal.

[0052] Specifically, the secondary side variable topology parameter and power measurement circuit 400 is connected to the topology and parameter variable rectifier circuit and the control test module 500 in the topology and parameter variable secondary side circuit 200, and is used to change the structure and parameters of the topology and parameter variable secondary side circuit 200 by comparing with the actual secondary side circuit of the isolated switching power supply in which the simulated external measured transformer works; drive the synchronous rectifier tube in the topology and parameter variable secondary side circuit 200 by comparing with the actual working condition of the isolated switching power supply in which the simulated external measured transformer works; and select the secondary side voltage and secondary side current signals of the external measured transformer of different ranges for segmented integration according to the collected bridge arm voltage signal to obtain an accurate secondary side power signal.

[0053] Specifically, the control test module 500 includes a variable topology, power closed-loop control, and test integrated controller, and is connected to the topology and parameter variable primary circuit 100, the topology and parameter variable secondary circuit 200, the primary side topology variable parameter and power measurement circuit 300, and the secondary side topology variable parameter and power measurement circuit 400. It is used to change the structure and parameters of the topology and parameter variable primary circuit 100 and the topology and parameter variable secondary circuit 200 through the primary side topology variable parameter and power measurement circuit 300 and the secondary side topology variable parameter and power measurement circuit 400 according to the actual situation of the isolated switching power supply in which the simulated external tested transformer works, control the isolated switching power supply transformer loss test circuit, that is, the isolated switching power supply transformer loss test circuit simulates the operation of the isolated switching power supply; collect the power measurement results of the primary side topology variable parameter and power measurement circuit 300 and the secondary side topology variable parameter and power measurement circuit 400.

[0054] For example, Figure 1 As shown, P1, P2, N1, and N2 respectively represent the nodes for current input and output between the external transformer under test and the isolated switching power supply transformer loss test circuit.

[0055] In the present embodiment, an isolated switching power supply transformer loss test circuit is provided, which can simulate the actual working conditions of the transformer in various types of isolated switching power supplies, so that the transformer voltage and current waveforms and values ​​are the same as when it actually works in the power supply; at the same time, the voltage and current sampling delay and the piecewise integration method based on the circuit mode enable the isolated switching power supply transformer loss test circuit in the present embodiment to accurately collect the transformer electrical and accurately calculate the primary and secondary power.

[0056] In an exemplary embodiment, Figure 1 As shown, the primary circuit 100 with variable topology and parameters includes a variable parameter DC input interface 102, a primary bridge arm 104 with variable topology and parameters, a short-circuitable resonant interface 106, a small-range adjustable simultaneous delay primary current sampling circuit 108, a large-range adjustable simultaneous delay primary current sampling circuit 110, a small-range adjustable simultaneous delay primary voltage sampling circuit 112, a large-range adjustable simultaneous delay primary voltage sampling circuit 114, a simultaneous delay first bridge arm voltage sampling circuit 116, a simultaneous delay second bridge arm voltage sampling circuit 118, and a primary low parasitic parameter bridge arm lead-out terminal 120, which is used to simulate the primary circuit topology and parameters of the isolated switching power supply in which the external transformer under test works; outputs primary voltage and primary current sampling signals of two ranges of the external transformer under test, and outputs two bridge arm voltage sampling signals, and the output sampling signals have the same delay relative to the actual electrical quantity of the sampled circuit.

[0057] Furthermore, the variable parameter DC input interface 102 is connected to the external input DC voltage, the topology and parameter variable primary bridge arm 104 in the external electrical equipment; the topology and parameter variable primary bridge arm 104 is connected to the variable parameter DC input interface 102, the short-circuitable resonance interface 106, the small-range adjustable same-delay primary voltage sampling circuit 112, the same-delay first bridge arm voltage sampling circuit 116, the same-delay second bridge arm voltage sampling circuit 118, the primary low parasitic parameter bridge arm lead-out terminal 120, the bridge arm power tube drive circuit 302 in the primary variable topology variable parameter and power measurement circuit 300, and the primary topology switching switch drive circuit 304; the short-circuitable resonance interface 106 is connected to the external The resonant inductor, topology and variable parameter primary bridge arm 104, the small-range adjustable delayed primary current sampling circuit 108, the small-range adjustable delayed primary voltage sampling circuit 112, the large-range adjustable delayed primary voltage sampling circuit 114, and the delayed first bridge arm voltage sampling circuit 116 are connected; the small-range adjustable delayed primary current sampling circuit 108 is connected to the short-circuited resonant interface 106 and the large-range adjustable delayed primary current sampling circuit 110; the large-range adjustable delayed primary current sampling circuit 110 is connected to the small-range adjustable delayed primary current sampling circuit 108 and the primary low parasitic parameter bridge arm lead-out terminal 120; the small-range adjustable delayed primary voltage sampling circuit 112 is connected to the topology and parameter The variable primary bridge arm 104, the short-circuited resonant interface 106, the small-range adjustable simultaneous delay primary current sampling circuit 108, the large-range adjustable simultaneous delay primary voltage sampling circuit 114, the simultaneous delay second bridge arm voltage sampling circuit 118, and the primary low parasitic parameter bridge arm lead-out terminal 120 are connected; the large-range adjustable simultaneous delay primary voltage sampling circuit 114 is connected to the short-circuited resonant interface 106, the small-range adjustable simultaneous delay primary current sampling circuit 108, and the small-range adjustable simultaneous delay primary voltage sampling circuit 112; the simultaneous delay first bridge arm voltage sampling circuit 116 is connected to the topology and parameter variable primary bridge arm 104 and the short-circuited resonant interface 106, and is connected to the node A; the simultaneous delay second bridge arm voltage sampling circuit Block 118 is connected to the topology and parameter variable primary bridge arm 104, the small-scale adjustable same-delay primary voltage sampling module 112, and the primary low parasitic parameter bridge arm lead-out terminal 120; the primary low parasitic parameter bridge arm lead-out terminal 120 is connected to the external measured transformer, the topology and parameter variable primary bridge arm 104, the large-scale adjustable same-delay primary current sampling circuit 110, the small-scale adjustable same-delay primary voltage sampling circuit 112, and the same-delay second bridge arm voltage sampling circuit 118, wherein the primary low parasitic parameter bridge arm lead-out terminal 120 is connected to the topology and parameter variable primary bridge arm 104, the small-scale adjustable same-delay primary voltage sampling module 112, and the same-delay second bridge arm voltage sampling circuit 118 at node B.

[0058] In this embodiment, the composition structure of the primary circuit with variable topology and parameters is further clarified to ensure that the function of the isolated switching power supply transformer loss test circuit can be realized.

[0059] In an exemplary embodiment, Figure 1 As shown, the first target current i p It flows out from the short-circuit resonant interface 106, passes through the small-scale adjustable simultaneous delay primary current sampling circuit 108, the large-scale adjustable simultaneous delay primary current sampling circuit 110, and the primary low parasitic parameter bridge arm lead-out terminal 120 to reach the external measured transformer, and then flows out from the external measured transformer through the primary low parasitic parameter bridge arm lead-out terminal 120, the simultaneous delay second bridge arm voltage sampling circuit 118, the small-scale adjustable simultaneous delay primary voltage sampling circuit 112, and the topology and parameter variable primary bridge arm 104. The small-scale sampled primary current obtained by the small-scale adjustable simultaneous delay primary current sampling circuit 108 is recorded as i p1 The large-scale adjustable delay primary current sampling circuit 110 obtains a large-scale sampling primary current and is recorded as i p2 The small-scale adjustable delay primary voltage sampling circuit 112 obtains the small-scale sampled primary voltage and is recorded as v p1 The large-scale adjustable delay primary voltage sampling circuit 114 obtains a large-scale sampling primary voltage, which is recorded as v p2 The first bridge arm voltage sampling circuit 116 obtains the first bridge arm sampling voltage with the same delay as v A1 The second bridge arm voltage sampling circuit 118 obtains the second bridge arm sampling voltage with the same delay, and the second bridge arm sampling voltage is recorded as v B1 .

[0060] In this embodiment, the current flow direction and voltage of the primary circuit with variable topology and parameters are further clarified to ensure the accuracy of the results of the isolated switching power supply transformer loss test circuit.

[0061] In an exemplary embodiment, Figure 1 As shown, the topology and parameter variable secondary circuit 200 includes a secondary low parasitic parameter rectifier introduction terminal 202, a topology and parameter variable rectifier circuit 204, a short-circuitable filter inductor interface and current sampling circuit 206, a load interface and output voltage sampling circuit 208, a small-range adjustable and delayed secondary voltage sampling circuit 210, a large-range adjustable and delayed secondary voltage sampling circuit 212, a small-range adjustable and delayed secondary current sampling circuit 214, and a large-range adjustable and delayed secondary current sampling circuit 216, which are used to simulate the secondary circuit topology structure and parameters of the isolated switching power supply in which the external measured transformer works; output two ranges of secondary voltage and secondary current sampling signals of the external measured transformer, and the output sampling signals have the same delay relative to the actual electrical quantity of the sampled circuit.

[0062] Furthermore, the secondary side low parasitic parameter rectifier introduction terminal 202 is connected to the external measured transformer, the topology and parameter variable rectifier circuit 204, the small-scale adjustable and delayed secondary side voltage sampling circuit 210, the large-scale adjustable and delayed secondary side voltage sampling circuit 212, and the large-scale adjustable and delayed secondary side current sampling circuit 216; the topology and parameter variable rectifier circuit 204 is connected to the secondary side low parasitic parameter rectifier introduction terminal 202, the short-circuit filter inductor interface and current sampling circuit 206, the load interface and output voltage sampling circuit 208, the small-scale adjustable and delayed secondary side voltage sampling circuit 210, the large-scale adjustable and delayed secondary side voltage sampling circuit 212, the small-scale adjustable and delayed secondary side current sampling circuit 216. The adjustable simultaneous delay secondary current sampling circuit 214, the rectifier tube synchronous rectification optional driving circuit 402 in the secondary variable topology variable parameter and power measurement circuit 400 are connected to the secondary topology switching switch driving circuit 404; the short-circuit filter inductor interface and current sampling circuit 206 are connected to the external filter inductor, topology and parameter variable rectifier circuit 204 in the external electrical equipment; the load interface and output voltage sampling circuit 208 are connected to the external load, topology and parameter variable rectifier circuit 204 in the external electrical equipment; the small-scale adjustable simultaneous delay secondary voltage sampling circuit 210 is connected to the secondary low parasitic parameter rectifier introduction terminal 202, topology and parameter variable rectifier circuit 2 04, a large range adjustable delay secondary voltage sampling circuit 212, a large range adjustable delay secondary current sampling circuit 216 are connected; the large range adjustable delay secondary voltage sampling circuit 212 is connected to the secondary low parasitic parameter rectification introduction terminal 202, the topology and parameter variable rectification circuit 204, and the large range adjustable delay secondary current sampling circuit 216, wherein the secondary low parasitic parameter rectification introduction terminal 202, the topology and parameter variable rectification circuit 204, the small range adjustable delay secondary voltage sampling circuit 210, and the large range adjustable delay secondary voltage sampling circuit 212 are connected to the node C; the small range adjustable delay secondary current sampling circuit 214 is connected to the topology The variable parameter rectifier circuit 204 and the large-range adjustable delayed secondary current sampling circuit 216 are connected; the large-range adjustable delayed secondary current sampling circuit 216 is connected to the secondary low parasitic parameter rectifier introduction terminal 202, the small-range adjustable delayed secondary voltage sampling circuit 210, the large-range adjustable delayed secondary voltage sampling circuit 212, and the small-range adjustable delayed secondary current sampling circuit 214, wherein the large-range adjustable delayed secondary current sampling circuit 216 is connected to the secondary low parasitic parameter rectifier introduction terminal 202, the small-range adjustable delayed secondary voltage sampling circuit 210, and the large-range adjustable delayed secondary voltage sampling circuit 212 are connected to the node D.

[0063] In this embodiment, the composition structure of the secondary circuit with variable topology and parameters is further clarified to ensure that the function of the isolated switching power supply transformer loss test circuit can be realized.

[0064] In an exemplary embodiment, Figure 1 As shown, the second target current i s Flowing out from the topology and variable parameters rectifier circuit 204, passing through the small-scale adjustable and delayed secondary current sampling circuit 214, the large-scale adjustable and delayed secondary current sampling circuit 216, and the secondary low parasitic parameter rectifier input terminal 202; the third target current i o The current flows out from the topology and parameter variable rectifier circuit 204 through the load interface and output voltage sampling circuit 208 to the external load, and then returns to the topology and parameter variable rectifier circuit 204 through the load interface and output voltage sampling circuit 208; the current between the topology and parameter variable rectifier circuit 204 and the short-circuit filter inductor interface and current sampling circuit 206 is recorded as i L The small-scale adjustable delay secondary voltage sampling circuit 210 obtains a small-scale sampled secondary voltage and is recorded as v s1 The large-scale adjustable delay secondary voltage sampling circuit 212 obtains a large-scale sampled secondary voltage and is recorded as v s2 The small-scale adjustable delay secondary current sampling circuit 214 obtains the small-scale sampling secondary current and is recorded as i s1 The large-scale adjustable delay secondary current sampling circuit 216 obtains a large-scale sampling secondary current and is recorded as i s2 .

[0065] In this embodiment, the current flow direction and voltage of the secondary circuit with variable topology and parameters are further clarified to ensure the accuracy of the results of the isolated switching power supply transformer loss test circuit.

[0066] In an exemplary embodiment, Figure 1 As shown, the primary side variable topology parameter and power measurement circuit 300 includes a bridge arm power tube driving circuit 302, a primary side topology switching switch driving circuit 304, and a transformer primary side power segmented integration circuit 306 based on the power supply mode, which is used to change the structure and parameters of the primary side circuit with variable topology and parameters by comparing with the actual primary side circuit of the isolated switching power supply in which the simulated external measured transformer works; drive the primary side bridge arm power tube of the primary side circuit with variable topology and parameters by comparing with the actual working conditions of the isolated switching power supply in which the simulated external measured transformer works; and select the primary side voltage and primary side current signals of the external measured transformer of different ranges for segmented integration according to the collected bridge arm voltage signal to obtain an accurate primary side power signal.

[0067] Furthermore, the bridge arm power tube driving circuit 302 is connected to the topology and parameter variable primary bridge arm 104; the primary side topology switching switch driving circuit 304 is connected to the topology and parameter variable primary bridge arm 104; the transformer primary side power segmented integration circuit 306 based on the power supply mode integrates the data i measured by the topology and parameter variable primary circuit 100 p1 、i p2 、vp1 、v p2 、v A1 、v B1 Perform integral operation.

[0068] In this embodiment, the components and structures of the primary transformer topology parameters and the power measurement circuit are further clarified to ensure that the functions of the isolated switching power supply transformer loss test circuit can be realized.

[0069] In an exemplary embodiment, Figure 1 As shown, the secondary side variable topology variable parameter and power measurement circuit 400 includes a rectifier tube synchronous rectification optional drive circuit 402, a secondary side topology switching switch drive circuit 404, and a transformer secondary side power segmented integration circuit 406 based on the power supply mode, which is used to change the structure and parameters of the secondary side circuit with variable topology and parameters by comparing with the actual secondary side circuit of the isolated switching power supply in which the simulated external measured transformer works; drive the synchronous rectifier tube of the secondary side circuit with variable topology and parameters by comparing with the actual working conditions of the isolated switching power supply in which the simulated external measured transformer works; and select the secondary side voltage and secondary side current signals of the external measured transformer with different ranges for segmented integration according to the collected bridge arm voltage signal to obtain an accurate secondary side power signal.

[0070] Furthermore, the rectifier synchronous rectifier optional drive circuit 402 is connected to the topology and parameter variable rectifier circuit 204; the secondary side topology switching switch drive circuit 404 is connected to the topology and parameter variable rectifier circuit 204; the transformer secondary side power segment integration circuit 406 based on the power supply mode integrates the data i measured by the topology and parameter variable primary circuit 100 and the topology and parameter variable secondary circuit 200 s1 、i s2 、v s1 、v s2 、v A1 、v B1 Perform integral operation.

[0071] In this embodiment, the components and structures of the secondary transformer topology parameters and the power measurement circuit are further clarified to ensure that the functions of the isolated switching power supply transformer loss test circuit can be realized.

[0072] In an exemplary embodiment, the working principle of the primary circuit of various types of isolated switching power supplies is simulated as follows: Figure 2 The variable parameter DC input interface 102 includes n (n=1, 2...n) columns of circuit units, each of which includes switches S i(2n-1) , capacitor C i(2n-1) , switch S i2n , capacitor C i2n , switch S i(2n-1)The first end of the switch S is the upper node of the column circuit unit. i(2n-1) The second end of the capacitor C i(2n-1) The first end of the capacitor C i(2n-1) The second end of the switch S i2n The first end of the switch S i2n The second end of the capacitor C i2n The first end of the capacitor C i2n The second end of is the ground node of the column circuit unit, and the upper node, the middle node and the ground node of each column circuit unit are connected to each other. The topology and parameter variable primary bridge arm 104 includes n (n = 1, 2 ... n) column circuit units, multiple sub-circuit units and a circuit combination unit, wherein each column circuit unit includes a switch S in turn. c(2n-1) , capacitor C c(2n-1) , switch S c2n , capacitor C c2n , switch S c(2n-1) The first end of the switch S is the upper node of the column circuit unit. c(2n-1) The second end of the capacitor C c(2n-1) The first end of the capacitor C c(2n-1) The second end of the switch S c2n The first end of the switch S c2n The second end of the capacitor C c2n The first end of the capacitor C c2n The second end of is the ground node of the column circuit unit, and the upper node, the middle node and the ground node of each column circuit unit are connected to each other respectively; the kth (k=1, 2, 3, 4) sub-circuit unit includes a switch S bQk 、MOS tube Q bk , switch S bDk 、Diode D bk and n (n=1, 2...n) circuit combinations, each of which includes a switch S bCkn and capacitor C bCkn , switch S bCkn The first end of the circuit combination is the first end of the switch S bCkn The second end of the capacitor C bCkn The first end of the capacitor C bCkn The second end of the circuit combination is the second end of the switch S bQk The second end of the MOS tube Q bk The first end of the switch S bDk The second end of the diode D bk The negative pole of the switch S bQk The first end of the switch S bDk The first end of the MOS tube Q is connected to the first end of the circuit combination.bk The second end of the diode D bk The positive electrode of the MOS tube Q is connected to the second end of the circuit combination; further, the MOS tube Q b1 The second end of the diode D b1 The positive electrode of the corresponding circuit combination is connected to the node A, and the MOS tube Q b3 The second end of the diode D b3 The positive electrode of the corresponding circuit combination is connected to the node B, and the switch S bQ2 The first end of the switch S bD2 The first end of the corresponding circuit combination is connected to the node A, and the switch S bQ4 The first end of the switch S bD4 The first end of the corresponding circuit combination is connected to the node B, and the MOS tube Q b2 The second end of the diode D b2 The positive electrode, MOS tube Q b4 The second end of the diode D b4 The positive electrode of the corresponding circuit combination is connected to the ground node; the circuit combination unit includes a switch S c1 , switch S c2 , switch S c3 、Diode D c1 and diode D c2 , where switch S c1 The first end of the switch S c2 The first end of the switch S c3 The first end of the switch S is connected to the node B. c1 The second end of the diode D c1 The positive connection of switch S c2 The second end of the diode D c2 The cathode of the diode D c1 The cathode of the diode D c2 The positive pole of switch S c3 The short-circuitable resonant interface 106 includes n (n=1, 2, ... n) circuit combinations, switches S r1L and switch S r1S , where each circuit combination includes a capacitor C rn and switch S r1Cn , capacitor C rn The first end of the circuit combination is the first end of the capacitor C rn The second end of the switch S r1Cn The first end of the connection, S r1Cn The second end of the circuit combination is the second end of the circuit combination, and the first end of each circuit combination is connected to each other and connected to the switch S r1SThe first end of each circuit combination is connected to each other and connected to the switch S r1L The first end of the switch S r1L The second end of the switch S r1S The second end of the connection.

[0073] For example, Figure 3 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ4 Close to obtain the primary side circuit of the isolated switching power supply single-tube flyback.

[0074] For example, Figure 4 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ1 , switch S bQ4 , switch S bD2 And switch S bD3 Close to obtain the primary circuit of the isolated switching power supply double-tube flyback.

[0075] For example, Figure 3 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ4 Close to obtain the primary circuit of the isolated single-tube forward switching power supply.

[0076] For example, Figure 4 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ1 , switch S bQ4 , switch S bD2 And switch S bD3 Close to obtain the primary circuit of the isolated switching power supply double-tube forward.

[0077] For example, Figure 5 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ3 and switch S bQ4 Close to obtain the primary circuit of the active clamped forward of the isolated switching power supply.

[0078] For example, Figure 6 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ1 , switch S bQ2 , switch S bQ3 And switch S bQ4 Close to obtain the primary circuit of the isolated switching power supply full-bridge circuit.

[0079] For example, Figure 7 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ1 , switch S bQ2 Close to obtain the primary circuit of the isolated switching power supply half-bridge circuit.

[0080] For example, Figure 8 As shown, by Figure 2 Simulate the switch S in the primary circuit of various isolated switching power supplies bQ1 , switch S bQ2 , switch S r1S And switch S r1C1 It is closed and forms the primary circuit of the isolated LLC power supply (Inductor-Inductor-Capacitor Resonant Converters) with the external resonant inductor.

[0081] In an exemplary embodiment, the schematic diagram of the working principle of simulating the secondary side circuit of various types of isolated switching power supplies is as follows: Fig. 9 shown.

[0082] For example, Fig.10 As shown, by Fig. 9 Simulate the switch S in the secondary circuit of various isolated switching power supplies f1 Close to obtain the secondary side circuit of the half-wave rectifier of the isolated switching power supply.

[0083] For example, Fig.11 As shown, by Fig. 9 Simulate the switch S in the secondary circuit of various isolated switching power supplies f1 and switch S f3 Close to obtain the secondary side circuit of the full-wave rectification of the isolated switching power supply.

[0084] For example, Fig.12 As shown, by Fig. 9 Simulate the switch S in the secondary circuit of various isolated switching power supplies f1 , switch S f2 , switch S f3 And switch S f4 Close to obtain the secondary side circuit of the isolated switching power supply full-bridge rectifier.

[0085] In an exemplary embodiment, Fig.13As shown, a current sampling circuit module in an isolated switching power supply transformer loss test circuit is provided, which is used for a small-range adjustable co-delay primary current sampling circuit 108, a large-range adjustable co-delay primary current sampling circuit 110, a small-range adjustable co-delay secondary current sampling circuit 214, and a large-range adjustable co-delay secondary current sampling circuit 216, including:

[0086] Delay circuit, the circuit is to set the parameters of the sampling circuit to obtain different delays according to the different delays of the sensor, so that the total delay time of the collected transformer voltage, current, and bridge arm voltage is the same. The delay circuit is composed of multiple groups of capacitors (Ci1, Ci2...Cin) and switches (Si1, Si2...Sin) in parallel. Different capacitor combinations are obtained by closing and closing the switches to achieve different delays and achieve the purpose of delay;

[0087] An amplifier U1 has a positive input terminal, a negative input terminal and an output terminal, wherein the output terminal of the amplifier U1 is connected to a resistor R8 and connected to a positive input terminal of an amplifier U2;

[0088] A bias circuit is connected to the positive input terminal of the amplifier U1, and the bias circuit includes a resistor R5, a resistor R6 and a capacitor C2, a first end of the resistor R5 is connected to the power supply terminal, a first end of the resistor R6 and a first end of the capacitor C2 are grounded, and a second end of the resistor R5, a second end of the resistor R6 and a second end of the capacitor C2 are connected to the positive input terminal of the amplifier U1;

[0089] A current sampling circuit is connected to the positive input terminal of the amplifier U1 and the negative input terminal of the amplifier U1 respectively, and is used to detect the current of the isolated switching power supply transformer loss test circuit. The current sampling circuit includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R7, a capacitor C1, and a capacitor group for delay. The first end of the capacitor C1 and the first end of the resistor R3 are connected to the positive input terminal of the amplifier U1, the second end of the capacitor C1 and the negative input terminal of the amplifier U1 are connected to the common ground terminal through the first end of the resistor R4, the second end of the resistor R4 and the first end of the resistor R2 are connected to the common ground terminal, the second end of the resistor R2 is connected to the second end of R3 and the second end of R1 and the first end of the capacitor group for delay, the first end of the resistor R1 is connected to the sampling current input in the isolated switching power supply transformer loss test circuit, the second end of the capacitor group for delay is connected to the common ground terminal, the first end of the resistor R7 is connected to the negative input terminal of the amplifier U1, and the second end of the resistor R7 is connected to the output terminal of the amplifier U1;

[0090] An amplifier U2 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U2 is connected to the measurement current output;

[0091] A voltage follower includes an amplifier U2, a resistor R8, and a resistor R9. The first end of the resistor R8 is connected to the output end of the previous amplifier U1, the second end of the resistor R8 is connected to the positive input end of the amplifier U2, the first end of the resistor R9 is connected to the negative input end of the amplifier U2, and the second end of the resistor R9 is connected to the output end of the amplifier U2. The voltage follower is used to maintain the stability of the sampling circuit signal.

[0092] The first end of the resistor R10 is connected to the second end of the resistor R9 and the output end of the amplifier U2, the second end of the resistor R10 is connected to the first end of the capacitor C3, the second end of the capacitor C3 is connected to the common ground, and the output end of the voltage follower is filtered out of noise through the resistor R10 and the capacitor C3 and is calculated through an ADC (Analog-to-digital converter) as a current sampling result output in the isolated switching power supply transformer loss test circuit.

[0093] In an exemplary embodiment, Fig.14 As shown, a voltage sampling circuit module in an isolated switching power supply transformer loss test circuit is provided, which is used for a small-range adjustable co-delay primary voltage sampling circuit 112, a large-range adjustable co-delay primary voltage sampling circuit 114, a small-range adjustable co-delay secondary voltage sampling circuit 210, and a large-range adjustable co-delay secondary voltage sampling circuit 212, including:

[0094] Delay circuit, this circuit is designed to be able to set parameters of the sampling circuit to obtain different delays according to the different delays of the sensor, so that the total delay time of the collected transformer voltage, current, and bridge arm voltage is the same. The delay circuit is composed of multiple groups of capacitors (Ci1, Ci2...Cin) and switches (Si1, Si2...Sin) in parallel. Different capacitor combinations are obtained by closing and closing the switches to achieve different delays and achieve the purpose of delay;

[0095] The amplifier U1 has a positive input terminal, a negative input terminal and an output terminal, the output terminal of the amplifier U1 is connected to the resistor R6 and connected to the positive input terminal of the amplifier U2; the first end of the resistor R5 is connected to the negative input terminal of the amplifier U1, and the second end of the resistor R5 is connected to the output terminal of the amplifier U1;

[0096] The voltage sampling circuit is connected to the positive input terminal of the amplifier U1 and is used to detect the voltage in the isolated switching power supply transformer loss test circuit. The voltage sampling circuit includes a resistor R1, a sliding rheostat R2, a resistor R3, a resistor R4, a capacitor C1, and a capacitor group for delay. The first end of the resistor R4 is connected to the positive input terminal of the amplifier U1, the second end of the resistor R4 is connected to the slider of the sliding rheostat R2, the first end of the sliding rheostat R2, the first end of the resistor R3, and the first end of the capacitor C1. The second end of the capacitor C1 and the second end of the resistor R3 are connected to the common ground terminal. The second end of the sliding rheostat R2 is connected to the second end of the resistor R1 and the first end of the capacitor group of the delay circuit. The second end of the capacitor group of the delay circuit is connected to the common ground terminal. The first end of the resistor R1 is connected to the sampling voltage input in the isolated switching power supply transformer loss test circuit;

[0097] An amplifier U2 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U2 is connected to the measurement voltage output;

[0098] A voltage follower includes an amplifier U2, a resistor R6, and a resistor R7. The first end of the resistor R6 is connected to the output end of the previous amplifier U1, the second end of the resistor R6 is connected to the positive input end of the amplifier U2, the first end of the resistor R7 is connected to the negative input end of the amplifier U2, and the second end of the resistor R7 is connected to the output end of the amplifier U2. The purpose of the voltage follower is to maintain the stability of the sampling circuit signal;

[0099] The first end of the resistor R8 is connected to the second end of the resistor R7 and the output end of the amplifier U2, the second end of the resistor R8 is connected to the first end of the capacitor C2, the second end of the capacitor C2 is connected to the common ground, and the output end of the voltage follower is filtered out of noise through the resistor R8 and the capacitor C2 and output as the voltage sampling result in the isolated switching power supply transformer loss test circuit through ADC operation.

[0100] In an exemplary embodiment, Fig.15 As shown, a voltage judgment circuit in an isolated switching power supply transformer loss test circuit is provided, which determines whether to use a large range or a small range voltage sampling result through the voltage difference between the same-delay first bridge arm voltage sampling circuit 116 and the same-delay second bridge arm voltage sampling module 118, including:

[0101] An amplifier U1 has a positive input terminal, a negative input terminal and an output terminal, wherein the output terminal of the amplifier U1 is connected to a resistor R5 and connected to a negative input terminal of the amplifier U2;

[0102] A subtraction circuit includes an amplifier U1, a resistor R1, a resistor R2, a resistor R3, and a resistor R4, wherein a first end of the resistor R1 is connected to a bridge arm 2 sampling voltage, that is, connected to a delayed second bridge arm voltage sampling module 118, a second end of the resistor R1 and a first end of the resistor R4 are connected to a negative input terminal of the amplifier U1, a second end of the resistor R4 is connected to an output terminal of the amplifier U1, a first end of the resistor R2 is connected to a bridge arm 1 sampling voltage, that is, connected to a delayed first bridge arm voltage sampling circuit 116, a second end of the resistor R2 and a first end of the resistor R3 are connected to a positive input terminal of the amplifier U1, and a second end of the resistor R3 is connected to ground;

[0103] The amplifier U2 has a positive input terminal, a negative input terminal and an output terminal. The output terminal of the amplifier U2 is connected to the resistor R9 and connected to the negative input terminal of the amplifier U3, and is also connected to the gate of the switch tube Q1 through the resistor R11.

[0104] A first voltage comparison circuit includes an amplifier U2, a resistor R5, a resistor R6, a resistor R7, and a resistor R8, wherein a first end of the resistor R5 is connected to an output end of the subtraction circuit, a second end of the resistor R5 is connected to a negative input end of the amplifier U2, a first end of the resistor R6 is connected to a voltage input of a discrimination voltage, wherein the discrimination voltage is used to compare with a voltage difference between a first bridge arm voltage sampling circuit 116 with a same delay and a second bridge arm voltage sampling module 118 with a same delay, a second end of the resistor R6 and a first end of the resistor R7 and a first end of the resistor R8 are connected to a positive input end of the amplifier U2, a second end of the resistor R7 is connected to ground, and a second end of the resistor R8 is connected to an output end of the amplifier U2;

[0105] The amplifier U3 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U3 is connected to the resistor R12 and connected to the gate of the switch tube Q2;

[0106] A second voltage comparison circuit includes an amplifier U3, a resistor R9, and a resistor R10, wherein a first end of the resistor R9 is connected to an output end of the first voltage comparison circuit, a second end of the resistor R9 is connected to a negative input end of the amplifier U3, a second end of the resistor R10 is connected to ground, and a first end of the resistor R10 is connected to a positive input end of the amplifier U3;

[0107] A voltage range selection circuit includes a switch tube Q1, a switch tube Q2, a resistor R11, and a resistor R12. The drain of the switch tube Q1 is connected to the output voltage of a small-range sampling voltage, wherein the small-range sampling voltage includes a small-range adjustable and delayed primary voltage sampling circuit 112 and a small-range adjustable and delayed secondary voltage sampling circuit 210. The source of the switch tube Q1 is connected to the voltage input of an integration circuit, wherein the integration circuit includes a transformer primary power segment integration circuit 306 based on a power supply mode and a transformer secondary power segment integration circuit 406 based on a power supply mode. The gate of the switch tube Q1 is connected to the first end of the resistor R11, and the first end of the resistor R11 is connected to the The gates of the switch tubes Q5 and Q9 of the subsequent integration circuit are connected, the second end of the resistor R11 is connected to the output of the first voltage comparison circuit, the drain of the switch tube Q2 is connected to the output voltage of the large-scale sampling voltage, wherein the large-scale sampling voltage includes a large-scale adjustable delay primary voltage sampling circuit 114 and a large-scale adjustable delay secondary voltage sampling circuit 212, the source of the switch tube Q2 is connected to the voltage input of the integration circuit, the gate of the switch tube Q2 is connected to the first end of the resistor R12, and the first end of the resistor R12 is connected to the gates of the switch tubes Q7 and Q11 of the subsequent integration circuit, and the second end of the resistor R12 is connected to the output of the second voltage comparison circuit.

[0108] In an exemplary embodiment, Fig.16 As shown, a current judgment circuit in an isolated switching power supply transformer loss test circuit is provided, and the result is used to determine whether to use a large range or a small range current sampling result, including:

[0109] The amplifier U1 has a positive input terminal, a negative input terminal and an output terminal. The output terminal of the amplifier U1 is connected to the resistor R5 and connected to the negative input terminal of the amplifier U2, and is connected to the gate of the switch tube Q1 through the resistor R7.

[0110] A first voltage comparison circuit includes an amplifier U1, a resistor R1, a resistor R2, a resistor R3, and a resistor R4, wherein a first end of the resistor R1 is connected to a current sampling result output, a second end of the resistor R1 is connected to a negative input end of the amplifier U1, a first end of the resistor R2 is connected to a voltage input of a small current range, wherein the voltage input of the small current range is used to compare with the current sampling result output, a second end of the resistor R2 and a first end of the resistor R3 and a first end of the resistor R4 are connected to a positive input end of the amplifier U1, a second end of the resistor R3 is connected to ground, and a second end of the resistor R4 is connected to an output end of the amplifier U1;

[0111] The amplifier U2 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U2 is connected to the gate of the switch tube Q2 through a resistor R8;

[0112] A second voltage comparison circuit includes an amplifier U2, a resistor R5, and a resistor R6, wherein a first end of the resistor R5 is connected to the output of the first voltage comparison circuit, a second end of the resistor R5 is connected to the negative input end of the amplifier U2, a first end of the resistor R6 is connected to the positive input end of the amplifier U2, and a second end of the resistor R6 is connected to ground;

[0113] The voltage range selection circuit includes a switch tube Q1, a switch tube Q2, a resistor R7, and a resistor R8. The drain of the switch tube Q1 is connected to the output of a small-range sampling current, wherein the small-range sampling current includes a small-range adjustable co-delay primary current sampling circuit 108 and a small-range adjustable co-delay secondary current sampling circuit 214. The source of the switch tube Q1 is connected to the current input of the integration circuit. The gate of the switch tube Q1 is connected to the first end of the resistor R7. At the same time, the first end of the resistor R7 is connected to the gates of the switch tubes Q4 and Q8 of the subsequent integration circuit. The second end of the resistor R7 is connected to the gate of the switch tube Q4 and Q8 of the subsequent integration circuit. The end is connected to the output of the first voltage comparison circuit, the drain of the switch tube Q2 is connected to the output of a large-scale sampling current, wherein the large-scale sampling current includes a large-scale adjustable delay primary current sampling circuit 110 and a large-scale adjustable delay secondary current sampling circuit 216, the source of the switch tube Q2 is connected to the current input of the integration circuit, the gate of the switch tube Q2 is connected to the first end of the resistor R8, and the first end of the resistor R8 is connected to the gates of the switch tubes Q6 and Q10 of the subsequent integration circuit, and the second end of the resistor R8 is connected to the output of the second voltage comparison circuit.

[0114] In an exemplary embodiment, Fig.17 As shown, a power supply mode-based segmented integration circuit in an isolated switching power supply transformer loss test circuit, wherein the power supply mode-based segmented integration circuit includes a transformer primary power segmented integration circuit 306 based on the power supply mode and a transformer secondary power segmented integration circuit 406 based on the power supply mode, including:

[0115] An amplifier U1 has a positive input terminal, a negative input terminal and an output terminal, wherein the output terminal of the amplifier U1 is connected to the resistor R3 and connected to the negative input terminal of the amplifier U3;

[0116] A first logarithmic operation circuit includes an amplifier U1, a resistor R1, a resistor R2, and a transistor Q1, wherein a first end of the resistor R1 is connected to a measurement current input, wherein the measurement current includes a current measured by a topology and parameter variable primary circuit 100 and a topology and parameter variable secondary circuit 200, wherein a second end of the resistor R1 is connected to a collector of the transistor Q1 to a negative input end of the amplifier U1, an emitter of the transistor Q1 is connected to an output end of the amplifier U1, a base of the transistor Q1 is connected to ground, a first end of the resistor R2 is connected to a positive input end of the amplifier U1, and a second end of the resistor R2 is connected to ground;

[0117] An amplifier U2 has a positive input terminal, a negative input terminal and an output terminal, wherein the output terminal of the amplifier U2 is connected to the resistor R6 and connected to the negative input terminal of the amplifier U3;

[0118] A second logarithmic operation circuit includes an amplifier U2, a resistor R4, a resistor R5, and a transistor Q2, wherein a first end of the resistor R4 is connected to a measurement voltage input, wherein the measurement voltage includes a voltage measured by a topology and parameter variable primary circuit 100 and a topology and parameter variable secondary circuit 200, a second end of the resistor R4 is connected to a collector of the transistor Q2 to a negative input end of the amplifier U2, an emitter of the transistor Q2 is connected to an output end of the amplifier U2, a base of the transistor Q2 is connected to ground, a first end of the resistor R5 is connected to a positive input end of the amplifier U2, and a second end of the resistor R2 is connected to ground;

[0119] An amplifier U3 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U3 is connected to the input of a subsequent exponential operation circuit through a resistor R9;

[0120] An adding operation circuit includes an amplifier U3, a resistor R3, a resistor R6, a resistor R7, and a resistor R8, wherein a first end of the resistor R3 is connected to an output of the first logarithmic operation circuit, a first end of the resistor R6 is connected to an output of the second logarithmic operation circuit, a second end of the resistor R3, a second end of the resistor R6, and a first end of the resistor R7 are connected to a negative input end of the amplifier U3, a second end of the resistor R7 is connected to an output end of the amplifier U3, a first end of the resistor R8 is connected to a positive input end of the amplifier U3, and a second end of the resistor R8 is connected to ground;

[0121] An amplifier U4 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U4 is connected to the negative input terminal of the amplifier U5 through a resistor R12;

[0122] An exponential operation circuit, comprising an amplifier U4, a resistor R9, a resistor R10, a resistor R11, and a transistor Q3, wherein a first end of the resistor R9 is connected to an output of the adding operation circuit, a second end of the resistor R9 is connected to a base of the transistor Q3 to a collector of the transistor Q3, an emitter of the transistor Q3 and a first end of the resistor R11 are connected to a negative input terminal of the amplifier U4, a second end of the resistor R11 is connected to an output terminal of the amplifier U4, a first end of the resistor R10 is connected to a positive input terminal of the amplifier U4, and a second end of the resistor R10 is connected to ground;

[0123] An amplifier U5 having a positive input terminal, a negative input terminal and an output terminal, wherein the output terminal of the amplifier U5 is connected to the negative input terminal of the amplifier U6 via a resistor R15;

[0124] An integral operation circuit, comprising an amplifier U5, a resistor R12, a resistor R13, a resistor R14 and a capacitor C1, wherein a first end of the resistor R12 is connected to an output of the exponential operation circuit, a second end of the resistor R12, a first end of the resistor R13 and a first end of the capacitor C1 are connected to a negative input end of the amplifier U5, a second end of the resistor R13 and a second end of the capacitor C1 are connected to an output end of the amplifier U5, a first end of the resistor R14 is connected to a positive input end of the amplifier U5, and a second end of the resistor R14 is connected to ground;

[0125] The amplifier U6 has a positive input terminal, a negative input terminal and an output terminal. The output terminal of the amplifier U6 is connected to the negative input terminal of the amplifier U7 through a resistor R21 and is also connected to the drain of the switch tube Q12.

[0126] The proportional operation circuit includes an amplifier U6, a resistor R15, a resistor R16, a resistor R17, a resistor R18, a resistor R19, a resistor R20, a switch tube Q4, a switch tube Q5, a switch tube Q6, a switch tube Q7, a switch tube Q8, a switch tube Q9, a switch tube Q10, and a switch tube Q11. The first end of the resistor R15 is connected to the output of the integral operation circuit, and the second end of the resistor R15 is connected to the first end of the resistor R17, the first end of the resistor R18, the first end of the resistor R19, and the first end of the resistor R20. One end is connected to the negative input terminal of the amplifier U6, the second end of the resistor R17 is connected to the drain of the switch tube Q4, the source of the switch tube Q4 is connected to the drain of the switch tube Q5, the gate of the switch tube Q4 is connected to the small-scale current conduction signal of the current range judgment circuit, the gate of the switch tube Q5 is connected to the small-scale voltage conduction signal of the voltage range judgment circuit, the second end of the resistor R18 is connected to the drain of the switch tube Q6, the source of the switch tube Q6 is connected to the drain of the switch tube Q7, the gate of the switch tube Q6 is connected to the current range judgment circuit, and the gate of the switch tube Q7 is connected to the small-scale voltage conduction signal of the voltage range judgment circuit. The gate of the switch tube Q7 is connected to the large-range voltage conduction signal of the voltage range judgment circuit, the second end of the resistor R19 is connected to the drain of the switch tube Q8, the source of the switch tube Q8 is connected to the drain of the switch tube Q9, the gate of the switch tube Q8 is connected to the large-range current conduction signal of the current range judgment circuit, the gate of the switch tube Q9 is connected to the small-range voltage conduction signal of the voltage range judgment circuit, and the second end of the resistor R20 is connected to the drain of the switch tube Q10. The source of the switch tube Q10 is connected to the drain of the switch tube Q11, the gate of the switch tube Q10 is connected to the large-range current conduction signal of the current range judgment circuit, the gate of the switch tube Q11 is connected to the large-range voltage conduction signal of the voltage range judgment circuit, the source of the switch tube Q5 is connected to the source of the switch tube Q7, the source of the switch tube Q9, and the source of the switch tube Q11 to the output end of the amplifier U6, the first end of the resistor R16 is connected to the positive input end of the amplifier U6, and the second end of the resistor R16 is connected to the ground. Proportional operation circuits of different proportions are obtained by selecting the large and small current ranges of the current range judgment circuit and the large and small voltage ranges of the voltage range judgment circuit, so that the numerical range of the integral result of any range of voltage and current combination is the same;

[0127] The amplifier U7 has a positive input terminal, a negative input terminal and an output terminal, and the output terminal of the amplifier U7 is an integration result of a segmented integration circuit based on a power mode in an isolated switching power supply transformer loss test circuit;

[0128] The subtraction operation circuit includes an amplifier U7, a resistor R21, a resistor R22, a resistor R23, a resistor R24, and a switch tube Q12. The first end of the resistor R21 and the drain of the switch tube Q12 are connected to the output end of the amplifier U6. The second end of the resistor R21 and the first end of the resistor R24 ​​are connected to the negative input end of the amplifier U7. The second end of the resistor R24 ​​is connected to the output end of the amplifier U7. The source of the switch tube Q12 is connected to the first end of R22. The second end of the resistor R22 and the first end of the resistor R23 are connected to the positive input end of the amplifier U26. The second end of the resistor R23 is connected to the ground. The gate of the switch tube Q12 is connected to the variable topology, power closed-loop control, and test integrated controller in the control test module 500. When every few switching cycles, the variable topology, power closed-loop control, and test integrated controller in the control test module 500 give a gate signal to the switch tube Q12 to turn on the switch tube Q12. The subtraction circuit outputs a zero result once to achieve integration time of several switching cycles, that is, every few switching cycles, the integration is set to zero and then integrated again.

[0129] The isolated switching power supply transformer loss test circuit provided in the above embodiment can simulate the real working condition of the isolated switching power supply transformer, adapt to various isolated power supply topologies and their specific parameters, and provide guarantee for power online test calculation; the sampling signal delay makes the signal source based on the power calculation more credible; the segmented integration method based on the circuit mode solves the contradiction between the range and the small signal accuracy for the specific object of the power transformer. Based on the above aspects, the isolated switching power supply transformer loss test circuit can realize accurate analysis of the loss of various isolated switching power supply transformers.

[0130] It can be understood that the above-mentioned isolated switching power supply transformer loss test circuit can also adopt other forms, not limited to the forms mentioned in the above embodiments, as long as it can achieve the function of accurately analyzing the losses of various types of isolated switching power supply transformers.

[0131] In the description of this specification, the descriptions with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc., mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example, and circuit elements with the same number in different embodiments do not necessarily refer to the same circuit elements.

[0132] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An isolated switching power supply transformer loss test circuit, characterized in that: include: The primary circuit with variable topology and parameters is used to simulate the primary circuit topology and parameters of the external transformer under test, and output the primary voltage sampling signal, primary current sampling signal and two-bridge arm voltage sampling signal of the external transformer under test in two ranges; The secondary circuit with variable topology and parameters is used to simulate the secondary circuit topology and parameters of the external transformer under test, and output the secondary voltage sampling signal and the secondary current sampling signal of the external transformer under test in two ranges; The primary side variable topology variable parameter and power measurement circuit is connected with the primary side circuit with variable topology and parameters and the control test module, and is used to change the structure and parameters of the primary side circuit with variable topology and parameters, and select the primary side voltage signal and the primary side current signal of the external transformer under test of different ranges for segmented integration according to the sampled bridge arm voltage signal, so as to obtain the primary side power signal; The secondary side variable topology variable parameter and power measurement circuit is connected with the topology and parameter variable secondary side circuit and the control test module, and is used to change the structure and parameters of the topology and parameter variable secondary side circuit, and select the secondary side voltage signal and the secondary side current signal of the external transformer under test of different ranges for segmented integration according to the sampled bridge arm voltage signal, so as to obtain the secondary side power signal; The control test module is used to control the connected primary circuit with variable topology and parameters, the secondary circuit with variable topology and parameters, the primary circuit with variable topology and parameters and power measurement circuit, and the secondary circuit with variable topology and parameters and power measurement circuit, and collect the primary power signal of the primary circuit with variable topology and parameters and power measurement circuit and the secondary power signal of the secondary circuit with variable topology and parameters and power measurement circuit.

2. The isolated switching power supply transformer loss test circuit according to claim 1, characterized in that: The topology and parameter variable primary circuit comprises a variable parameter DC input interface, a topology and parameter variable primary bridge arm, a short-circuitable resonant interface, a small-range adjustable same-delay primary current sampling circuit, a large-range adjustable same-delay primary current sampling circuit, a small-range adjustable same-delay primary voltage sampling circuit, a large-range adjustable same-delay primary voltage flow sampling circuit, a same-delay first bridge arm voltage sampling circuit, a primary low parasitic parameter bridge arm lead-out terminal and a primary low parasitic parameter bridge arm lead-out terminal; wherein: The variable parameter DC input interface is connected to the external input DC voltage, the topology and parameter variable primary bridge arm; the topology and parameter variable primary bridge arm is connected to the short-circuit resonant interface, the small-scale adjustable same-delay primary voltage sampling circuit, the same-delay first bridge arm voltage sampling circuit, the same-delay second bridge arm voltage sampling circuit, the primary low parasitic parameter bridge arm lead-out terminal, the primary variable topology variable parameter and power measurement circuit; the short-circuit resonant interface is connected to the external resonant inductor, the small-scale adjustable same-delay primary current sampling circuit, the small-scale adjustable same-delay primary voltage sampling circuit, the large-scale adjustable same-delay primary voltage flow sampling circuit, and the same-delay first bridge arm voltage sampling circuit; the small-scale adjustable same-delay primary current sampling circuit is connected to the large-scale adjustable same-delay primary current sampling circuit , used to output a small-scale sampled primary current; a large-scale adjustable same-delay primary current sampling circuit is connected to the primary low parasitic parameter bridge arm lead-out terminal, used to output a large-scale sampled primary current; a small-scale adjustable same-delay primary voltage sampling circuit is connected to the same-delay second bridge arm voltage sampling circuit and the primary low parasitic parameter bridge arm lead-out terminal, used to output a small-scale sampled primary voltage; a large-scale adjustable same-delay primary voltage flow sampling circuit is used to output a large-scale sampled primary voltage; the same-delay first bridge arm voltage sampling circuit is used to output the first bridge arm sampling voltage; the same-delay second bridge arm voltage sampling circuit is connected to the primary low parasitic parameter bridge arm lead-out terminal, used to output the second bridge arm sampling voltage; the primary low parasitic parameter bridge arm lead-out terminal is connected to the external measured transformer.

3. The isolated switching power supply transformer loss test circuit according to claim 2, characterized in that: The first target current flows out from the short-circuited resonant interface, passes through the small-range adjustable same-delay primary current sampling circuit, the large-range adjustable same-delay primary current sampling circuit, and the primary low parasitic parameter bridge arm lead-out terminal to reach the external transformer under test, and then flows out from the external transformer under test through the primary low parasitic parameter bridge arm lead-out terminal, the same-delay second bridge arm voltage sampling circuit, the small-range adjustable same-delay primary voltage sampling circuit, and the topology and parameter variable primary bridge arm.

4. The isolated switching power supply transformer loss test circuit according to claim 2, characterized in that: The topology and parameter variable secondary circuit includes a secondary low parasitic parameter rectifier introduction terminal, a topology and parameter variable rectifier circuit, a short-circuit filter inductor interface and a current sampling circuit, a load interface and an output voltage sampling circuit, a small-range adjustable simultaneous delay secondary voltage sampling circuit, a large-range adjustable simultaneous delay secondary voltage sampling circuit, a small-range adjustable simultaneous delay secondary current sampling circuit and a large-range adjustable simultaneous delay secondary current sampling circuit; wherein: The secondary side low parasitic parameter rectifier introduction terminal is connected to the external measured transformer, the topology and parameter variable rectifier circuit, the small-scale adjustable delay secondary side voltage sampling circuit, the large-scale adjustable delay secondary side voltage sampling circuit, and the large-scale adjustable delay secondary side current sampling circuit; the topology and parameter variable rectifier circuit is connected to the short-circuit filter inductor interface and current sampling circuit, the load interface and output voltage sampling circuit, the small-scale adjustable delay secondary side voltage sampling circuit, the large-scale adjustable delay secondary side voltage sampling circuit, the small-scale adjustable delay secondary side current sampling circuit, the secondary side variable topology parameter and power measurement circuit; the short-circuit filter inductor interface and current sampling circuit are connected to the external filter inductor The load interface and the output voltage sampling circuit are connected to the external load; the small-scale adjustable delay secondary voltage sampling circuit is connected to the large-scale adjustable delay secondary voltage sampling circuit and the large-scale adjustable delay secondary current sampling circuit, and is used to output the small-scale sampled secondary voltage; the large-scale adjustable delay secondary voltage sampling circuit is connected to the large-scale adjustable delay secondary current sampling circuit, and is used to output the large-scale sampled secondary voltage; the small-scale adjustable delay secondary current sampling circuit is connected to the large-scale adjustable delay secondary current sampling circuit, and is used to output the small-scale sampled secondary current; the large-scale adjustable delay secondary current sampling circuit is used to output the large-scale sampled secondary current.

5. The isolated switching power supply transformer loss test circuit according to claim 4, characterized in that: The second target current flows out from the topology and parameter variable rectifier circuit, and passes through the small-scale adjustable and delayed secondary current sampling circuit, the large-scale adjustable and delayed secondary current sampling circuit, and the secondary low parasitic parameter rectifier introduction terminal respectively; the third target current flows out from the topology and parameter variable rectifier circuit, passes through the load interface and the output voltage sampling circuit to reach the external load, and returns to the topology and parameter variable rectifier circuit through the load interface and the output voltage sampling circuit.

6. The isolated switching power supply transformer loss test circuit according to claim 2, characterized in that: The primary side topology variable parameter and power measurement circuit includes a bridge arm power tube drive circuit, a primary side topology switch drive circuit and a transformer primary side power segmented integration circuit based on the power supply mode; wherein: The bridge arm power tube driving circuit and the primary side topology switching switch driving circuit are connected to the topology and parameter variable primary side bridge arm; the transformer primary side power segmented integration circuit based on the power supply mode is used to integrate the small-scale sampled primary side current, the large-scale sampled primary side current, the small-scale sampled primary side voltage, the large-scale sampled primary side voltage, the first bridge arm sampling voltage, and the second bridge arm sampling voltage in the topology and parameter variable primary side circuit.

7. The isolated switching power supply transformer loss test circuit according to claim 4, characterized in that: The secondary side topology variable parameter and power measurement circuit includes a rectifier tube synchronous rectification optional drive circuit, a secondary side topology switching switch drive circuit and a transformer secondary side power segmented integration circuit based on the power supply mode; wherein: The optional driving circuit for synchronous rectification of the rectifier tube and the secondary side topology switching switch driving circuit are connected to the topology and parameter variable rectification circuit; the transformer secondary side power segmented integration circuit based on the power supply mode is used to integrate the first bridge arm sampling voltage, the second bridge arm sampling voltage, the small-scale sampling secondary side voltage, the large-scale sampling secondary side voltage, the small-scale sampling secondary side current, and the large-scale sampling secondary side current in the topology and parameter variable primary circuit and the topology and parameter variable secondary circuit.

8. An isolated switching power supply transformer loss test device, characterized in that: It comprises an isolated switching power supply transformer loss test circuit according to any one of claims 1-7.

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