Switching type electronic load

Abstract

The invention provides a switching type electronic load which is used for testing a direct-current power supply. The switching type electronic load comprises a connecting end, a switching type circuit and an inductive component. The connecting end is used for being electrically connected with the output end of the direct-current power supply. The switching circuit selectively provides a first DC voltage in a first voltage range or a second DC voltage in a second voltage range according to a test command. The inductive component is electrically connected between the connecting end and the switching circuit. Wherein the first voltage range is not less than zero voltage, and the second voltage range is less than zero voltage. Wherein the test command is associated with an output voltage and an output current provided by the DC power supply, and the output voltage is a positive voltage.

Description

Technical Field

[0001] This application relates to a switching electronic load, and more particularly to a switching electronic load for testing DC power supplies. Background Technology

[0002] Traditionally, when testing DC power supplies, electronic loads are often used to receive the power supplied by the DC power supply. Currently, a common circuit architecture used in electronic loads is a linear circuit. While this type of electronic load has a fast response speed and can quickly draw current from the DC power supply, the power supplied by the DC power supply is consumed as heat by the linear circuit, making it impossible to recover and reuse the energy. To achieve energy saving, some electronic loads have begun to adopt a switching circuit architecture, using a switching circuit to feed the power supplied by the DC power supply back to the AC mains.

[0003] While electronic loads using switching circuits (switching electronic loads) can achieve higher energy recovery efficiency, they suffer from a problem in rapidly drawing current compared to electronic loads using linear circuit architectures because the current path includes inductive components. Therefore, the industry needs a switching electronic load that can rapidly draw current. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a switching electronic load having a switching circuit capable of selectively providing positive or negative DC voltage. Thus, when testing a DC power supply, the switching electronic load can quickly draw current.

[0005] This application discloses a switching electronic load for testing a DC power supply. The switching electronic load includes a connection terminal, a switching circuit, and an inductive component. The connection terminal is electrically connected to the output terminal of the DC power supply. The switching circuit selectively provides a first DC voltage within a first voltage range or a second DC voltage within a second voltage range, according to a test command. The inductive component is electrically connected between the connection terminal and the switching circuit. The first voltage range is not less than zero voltage, and the second voltage range is less than zero voltage. The test command is associated with the output voltage and output current provided by the DC power supply, and the output voltage is a positive voltage.

[0006] In some embodiments, when the switching circuit determines that the test command indicates that the rate of change of the output current over a specified time interval is not greater than a first threshold, the switching circuit provides a first DC voltage over the specified time interval. When the switching circuit determines that the test command indicates that the rate of change of the output current over the specified time interval is greater than the first threshold, the switching circuit provides a second DC voltage over the specified time interval.

[0007] In some embodiments, the switching circuit includes a first DC voltage source and a full-bridge switch group. When the switching circuit provides a first DC voltage during a specified time interval, the full-bridge switch group turns on the first switch group, causing the switching circuit to output the first DC voltage. When the switching circuit provides a second DC voltage during a specified time interval, the full-bridge switch group turns on the second switch group, causing the switching circuit to output the second DC voltage.

[0008] In some embodiments, the switching circuit includes a first DC voltage source and a second DC voltage source. When the switching circuit provides a first DC voltage during a specified time interval, the first DC voltage source provides the first DC voltage; when the switching circuit provides a second DC voltage during a specified time interval, the second DC voltage source provides the second DC voltage.

[0009] In summary, unlike traditional switching electronic loads where voltage changes can only occur between positive voltage ranges and current cannot be rapidly drawn in, the switching circuit of this embodiment can selectively switch to a negative DC voltage. This meets the increasingly shorter transition times required during testing, thus achieving the goal of rapidly drawing in current.

[0010] The other effects and embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a functional block diagram of a switching electronic load according to an embodiment of this application;

[0013] Figure 2 This is a schematic diagram of the output current of a DC power supply according to an embodiment of this application;

[0014] Figure 3 This is a voltage schematic diagram of a switching circuit according to an embodiment of this application;

[0015] Figure 4 This is a circuit diagram of a switching circuit according to an embodiment of this application;

[0016] Figure 5 This is a circuit diagram of a switching circuit according to another embodiment of this application.

[0017] Symbol Explanation

[0018] 1: Switching electronic load; 10: Connection terminal

[0019] 12: Switching circuit 120: First DC voltage source

[0020] 122: Full-bridge switch assembly; 14: Inductive components.

[0021] 2: DC power supply 20: Output terminal

[0022] 32: Switching circuit; 320: First DC voltage source

[0023] 322: Second DC voltage source S1~S4: Switch Detailed Implementation

[0024] In the embodiments described below, the positional relationships include: up, down, left, and right. Unless otherwise specified, they are all based on the direction shown by the components in the diagram.

[0025] Please see Figure 1 , Figure 1 This is a functional block diagram of a switching electronic load according to an embodiment of this application. For example... Figure 1 As shown, the connection terminal 10 of the switching electronic load 1 is connected to the output terminal 20 of the DC power supply 2, and the switching electronic load 1 is used to test the DC power supply 2. The switching electronic load 1 also has a switching circuit 12 and an inductive component 14, which is electrically connected between the connection terminal 10 and the switching circuit 12. In practice, the switching circuit 12 can provide a load voltage V. 12 The load voltage is used to resist the output voltage V of the DC power supply 2. DUT This simulates the impedance of the DC power supply 2 connected to an actual electronic product. In one example, Figure 1 The inductive component 14 indicated in the diagram may be the equivalent inductance of other circuits within the switching electronic load 1. Those skilled in the art will understand that the inductive component 14 is indicated for ease of explanation.

[0026] From the perspective of DC power supply 2, it should be seen that the connection terminal 10 of the switching electronic load 1 receives the entire output voltage V. DUT Since DC power supply 2 is the power provider, the output voltage V of DC power supply 2 is... DUT It must be a positive voltage; therefore, the load voltage provided by the traditional switching circuit also only needs to be a positive voltage to withstand the output voltage V of the DC power supply 2. DUTThat's fine. However, when the DC power supply 2 needs to switch states very quickly, the switching circuit, which traditionally only provides positive voltage, has the problem of not being able to quickly draw in load current. Specifically, the switching electronic load 1 and the DC power supply 2 also have the impedance of the connecting wires, for example, impedance L. wire Assuming the impedance of inductive component 14 is L, then the equivalent impedance between switching circuit 12 and the output terminal 20 of DC power supply 2 is (L + L). wire As will be understood by those skilled in the art, the voltage-current relationship between the switching circuit 12 and the DC power supply 2 can be expressed by the following formula (1):

[0027] (ΔV) = (L+L wire ) * (Δi / Δt) (1)

[0028] Here, ΔV in equation (1) is the equivalent impedance (L+L) wire The rate of change of voltage across the voltage, (Δi / Δt) is the output current I of DC power supply 2. Load The rate of change of current (current flowing into the switching electronic load 1). As can be seen from the above, at the equivalent impedance (L+L) wire With a fixed impedance, only the equivalent impedance (L+L) wire The greater the rate of change of the voltage across the voltage, the greater the output current I. Load The greater the rate of change of current (Δi / Δt), the greater the equivalent impedance (L+L) will be. wire The rate of change of voltage across the voltage is actually the output voltage V. DUT and load voltage V 12 The instantaneous voltage difference. Returning to the traditional switching circuit, since the load voltage provided by the traditional switching circuit is a positive voltage, the instantaneous voltage difference between the load voltage and the rated voltage of DC power supply 2 will occur when the load voltage is zero. The instantaneous voltage difference is the rated voltage of DC power supply 2, let's assume it's expressed as ΔV. max In other words, when using a traditional switching circuit, the equivalent impedance (L+L) wire Under fixed conditions, the traditional output current I Load The rate of change of rated current (Δi / Δt) max It is subject to the rated instantaneous voltage difference ΔV max Restrictions.

[0029] In other words, suppose there is a test command that requires the output current I of DC power supply 2. Load The rate of change of current (Δi / Δt) exceeds the rated rate of change of current (Δi / Δt). max Traditional switching circuits clearly cannot achieve rapid state transitions. Therefore, this embodiment uses the aforementioned rated current change rate (Δi / Δt).max This is called the first threshold, which can be seen as the upper limit of a traditional switching circuit that only provides a positive voltage. To allow the DC power supply 2 to output current I... Load The rate of change of current (Δi / Δt) can exceed the rated rate of change of current (Δi / Δt). max In this embodiment, the switching circuit 12 can selectively provide a first DC voltage within a first voltage range or a second DC voltage within a second voltage range according to a test command.

[0030] For ease of explanation, please refer to the following: Figure 1 and Figure 2 , Figure 2 This is a schematic diagram of the output current of a DC power supply according to an embodiment of this application. As shown in the figure, assume that the test command indicates the output current I of the DC power supply 2. Load It is 0 at time t0, and needs to be increased to the current value I at time t1. set Then, the output current I between time t0 and time t1 (the specified time interval) Load The slope of this slope is the aforementioned rate of change of current (Δi / Δt). Now, assuming the rated voltage of DC power supply 2 is known, then the aforementioned rated rate of change of current (Δi / Δt)... max This should also be known. As mentioned earlier, if the test command requires that the rate of change of current (Δi / Δt) over a specified time interval not exceed the rate of change of rated current (Δi / Δt)... max (First threshold) indicates that the switching circuit 12 can meet the requirements of the test command by providing a positive voltage of zero or above. That is to say, the first DC voltage of the aforementioned first voltage range can be a positive DC voltage greater than zero or a zero voltage, that is, the first voltage range should be a voltage range greater than or equal to zero.

[0031] Conversely, if the test command requires the current change rate (Δi / Δt) for a specified time interval to be greater than the rated current change rate (Δi / Δt)... max (First threshold) indicates that the switching circuit 12, by only providing a positive voltage, cannot meet the requirements of the test command. At this time, if... Figures 1 to 3 As shown, Figure 3 This is a voltage schematic diagram of a switching circuit according to an embodiment of this application. As shown, the switching circuit 12 provides a negative voltage -V between time t0 and time t1. b In this way, the output voltage V between time t0 and time t1 DUT and load voltage V 12 The instantaneous voltage difference can be greater than the aforementioned rated instantaneous voltage difference ΔV. max Instead, ΔV max +V bAs will be understood by those skilled in the art, due to the increased instantaneous voltage difference, the rate of change of current (Δi / Δt) over a specified time interval can be further increased, thereby enabling the switching electronic load 1 to more quickly change the output current I. Load The current is pulled to the predetermined value. In other words, the second DC voltage in the aforementioned second voltage range can be a negative DC voltage, meaning the second voltage range should be a voltage range less than zero.

[0032] In order for the switching circuit 12 to achieve the function of providing a negative DC voltage as described above Figure 4 This is a circuit diagram of a switching circuit according to an embodiment of this application. Figure 4 As shown, the switching circuit 12 may include a first DC voltage source 120 and a full-bridge switch group 122. The first DC voltage source 120 can provide a first DC voltage (positive DC voltage), while the full-bridge switch group 122 may include switches S1 to S4. In a practical example, when the switching circuit 12 determines that the rate of change of current (Δi / Δt) over a specified time interval has not exceeded the rated rate of change of current (Δi / Δt)... max When the threshold value is reached (first threshold), the switching circuit 12 can control switches S1 and S4 (first switch group) in the full-bridge switch group 122 to conduct within a specified time interval, so that the load voltage V provided by the switching circuit 12 is... 12 This is a positive DC voltage (first DC voltage). Conversely, when the switching circuit 12 determines that the rate of change of current (Δi / Δt) over a specified time interval has exceeded the rated rate of change of current (Δi / Δt)... max When the threshold (first threshold) is reached, the switching circuit 12 can control switches S2 and S3 (second switching group) in the full-bridge switching group 122 to conduct within a specified time interval, so that the load voltage V provided by the switching circuit 12 is... 12 It is a negative DC voltage (second DC voltage).

[0033] In addition to the above Figure 4 In addition to the examples, the switching circuit 12 can also use more than one DC voltage source, such as Figure 5 , Figure 5 This is a circuit diagram of a switching circuit according to another embodiment of this application. Figure 5 As shown, another switching circuit 32 may include a first DC voltage source 320 and a second DC voltage source 322, wherein the first DC voltage source 320 can provide a first DC voltage (positive DC voltage), and the second DC voltage source 322 can provide a second DC voltage (negative DC voltage). In a practical example, when the switching circuit 32 determines that the rate of change of current (Δi / Δt) over a specified time interval has not exceeded the rated rate of change of current (Δi / Δt)... maxWhen the threshold is reached, the switching circuit 32 can control the first DC voltage source 320 to provide the load voltage V. 12 This disconnects the second DC voltage source 322 from the current loop, thereby reducing the load voltage V. 12 This is a positive DC voltage (first DC voltage). Conversely, when the switching circuit 32 determines that the rate of change of current (Δi / Δt) within a specified time interval has exceeded the rated rate of change of current (Δi / Δt)... max When the first threshold is reached, the switching circuit 32 can control the second DC voltage source 322 to provide the load voltage V. 12 And thus disconnect the first DC voltage source 320 from the current loop, thereby reducing the load voltage V. 12 This is a negative DC voltage (second DC voltage). Of course, there are many circuit architectures that can provide both positive and negative DC voltages; this embodiment does not use them. Figure 4 and Figure 5 This is limited to two circuit architectures. In practice, any switching electronic load used to test a DC power supply that includes a circuit architecture capable of providing either a positive or negative DC voltage should fall within the scope of the switching circuit in this embodiment.

[0034] In summary, unlike traditional switching electronic loads where voltage changes can only occur between positive voltage ranges and current cannot be rapidly drawn in, the switching circuit of this embodiment can selectively switch to a negative DC voltage. This meets the increasingly shorter transition times required during testing, thus achieving the goal of rapidly drawing in current.

[0035] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of this application, and are not intended to limit the implementation methods of the technology of this application in any way. Any person skilled in the art may make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in this application, but these should still be regarded as the technology or embodiments that are substantially the same as those of this application.

Claims

1. A switching electronic load for testing a DC power supply, characterized in that, The switching electronic load includes: A connection terminal for electrically connecting to an output terminal of the DC power supply; A switching circuit, based on a test command, selectively provides a first DC voltage within a first voltage range or a second DC voltage within a second voltage range; and An inductive component is electrically connected between the connection terminal and the switching circuit; Wherein the first voltage range is not less than zero voltage, and the second voltage range is less than zero voltage; The test command is associated with an output voltage and an output current provided by the DC power supply, wherein the output voltage is a positive voltage.

2. The switching electronic load according to claim 1, characterized in that, When the switching circuit determines that the test command indicates that the rate of change of the output current in a specified time interval is greater than a first threshold, the switching circuit provides the second DC voltage in the specified time interval.

3. The switching electronic load according to claim 2, characterized in that, When the switching circuit determines that the test command indicates that the rate of change of the output current in the specified time interval is not greater than the first threshold, the switching circuit provides the first DC voltage in the specified time interval.

4. The switching electronic load according to claim 3, characterized in that, The switching circuit includes a first DC voltage source and a full-bridge switch group. When the switching circuit provides the first DC voltage during the specified time interval, the full-bridge switch group turns on a first switch group, causing the switching circuit to output the first DC voltage. When the switching circuit provides the second DC voltage during the specified time interval, the full-bridge switch group turns on a second switch group, causing the switching circuit to output the second DC voltage.

5. The switching electronic load according to claim 1, characterized in that, The switching circuit includes a first DC voltage source and a second DC voltage source. When the switching circuit provides the first DC voltage during the specified time interval, the first DC voltage source provides the first DC voltage; when the switching circuit provides the second DC voltage during the specified time interval, the second DC voltage source provides the second DC voltage.

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