An air volume adaptive test load

Abstract

The present invention relates to an air volume adaptive test load, comprising a load group, a fan, a terminal X1, and a terminal X2. The fan is aimed at the load group for blowing air. The load group includes a fan resistance unit RA and a tubular high-power resistor RB. The terminal X1 is connected in series with the fan resistance unit RA and the tubular high-power resistor RB and then connected to the terminal X2. The input end of the fan is connected to the two ends of the fan resistance unit RA. The total resistance of the fan resistance unit RA is such that, when the test load is operating at the maximum allowable voltage, a voltage U2 obtained by dividing the fan resistance unit RA is consistent with the rated voltage of the fan.

Description

Technical Field

[0001] The present invention relates to the field of electric loads, and in particular to an air volume adaptive test load. Background Art

[0002] The test load is connected to the output of the power supply under test (such as a generator or battery). It is usually designed to have full voltage capacity to meet the output voltage requirements of the power supply under test. Since it operates in a high-voltage scenario, a fan is required for heat dissipation and an additional power supply is provided to meet the fan voltage. The rated air volume of the fan meets the rated voltage and heat dissipation requirements of the test load.

[0003] Since the fan is powered by an additional power supply, when the voltage output of the power supply to be tested decreases, the fan still outputs full voltage, resulting in extra voltage waste for the fan. Summary of the Invention

[0004] In order to improve the deficiencies of the prior art, the present invention provides a test load in which the air volume output by a fan follows the voltage output variation of a power supply to be tested.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] Provided is an air volume adaptive test load, comprising a load group, a fan, a terminal X1, and a terminal X2. The fan is directed toward the load group for blowing air. The load group comprises a fan resistance unit RA and a tubular high-power resistor RB. The terminal X1 is connected in series with the fan resistance unit RA and the tubular high-power resistor RB and then to the terminal X2. The input end of the fan is connected to both ends of the fan resistance unit RA. The total resistance of the fan resistance unit RA is such that, when the test load is operating at the maximum allowable voltage, a voltage U2 obtained by dividing the fan resistance unit RA is consistent with the rated voltage of the fan.

[0007] Furthermore, the wind turbine resistance unit RA is composed of a plurality of cement resistors with the same resistance value connected in series.

[0008] Furthermore, each cement resistor is provided with a diode D, a varistor RN and a capacitor C, wherein the varistor RN is connected in series with the capacitor C and then connected in parallel to both ends of the cement resistor, and the diode D is connected in parallel to both ends of the varistor RN with the conduction direction pointing to the terminal X2.

[0009] Furthermore, the wind turbine resistance unit RA further includes a bidirectional thyristor SCR, which is connected in parallel to both ends of the wind turbine resistance unit RA, and a controlled end of the bidirectional thyristor SCR is connected to an external controller.

[0010] Furthermore, the voltage resistance level of the bidirectional thyristor SCR is 4000V or above.

[0011] Furthermore, the tubular high-power resistor RB has a plurality of them, and the plurality of tubular high-power resistors RB are connected in series to be suitable for high power.

[0012] Furthermore, the terminal X1, the terminal X2, the wind turbine resistance unit RA, and the tubular high-power resistor RB are connected via a copper busbar.

[0013] Furthermore, the load group has a shell connected to the ground, and the wind turbine resistance unit RA and the tubular high-power resistor RB are located in the shell; it also includes a terminal d and a terminal b for connecting to the wind turbine input end, and the terminal d and the terminal b are respectively connected to the two ends of the wind turbine resistance unit RA, and the terminal X1, the terminal d, the terminal b, and the terminal X2 extend out of the shell.

[0014] Beneficial effects:

[0015] The present invention controls the total resistance of the fan resistance unit RA so that when the test load is running at the highest allowable voltage, the voltage U2 obtained by voltage division is consistent with the rated voltage of the fan. In this way, since the output air volume of the fan is proportional to its input voltage U2, when the voltage connected to the test load decreases (that is, the voltage drops), the input voltage U2 of the fan also changes accordingly, thereby realizing adaptive adjustment of the air volume with voltage.

[0016] In addition, since there is no need to set up an additional power supply to power the fan, it can solve the problem of adapting the air volume to the voltage when there is no additional power supply outdoors, and achieve the purpose of reducing costs.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0019] Figure 1 Schematic diagram of the circuit structure of the test load of this embodiment.

[0020] Figure 2 Schematic diagram of the structure of the load group of this embodiment. DETAILED DESCRIPTION

[0021] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0022] See Figure 1 The test load of this embodiment consists of a load group 1 and a fan 2 blowing air toward the load group 1.

[0023] Load group 1 has Figure 2 The housing 11 shown in FIG. has four terminals X1, d, b, and X2 extending out of the housing 11. Figure 1 A plurality of tubular high-power resistors RB and a fan resistance unit RA are provided in the housing 11. The terminal X1 is connected in series with the plurality of tubular high-power resistors RB, and then the fan resistance unit RA is connected in series to the terminal X2.

[0024] The connection terminals d and b are connected to the two ends of the fan resistance unit RA respectively, and the input end of the fan 2 is connected to the connection terminals d and b respectively.

[0025] According to the series voltage division principle, the voltage U0 between the terminal X1 and the terminal X2 is equal to the voltage U1 across the two ends of the series connection of multiple tubular high-power resistors RB plus the voltage U2 of the fan resistance unit RA.

[0026] By controlling the total resistance of the fan resistor unit RA, the voltage U2 obtained by voltage division is consistent with the rated voltage of fan 2 when the test load is operating at the maximum allowable voltage. In this way, since the output air volume of fan 2 is proportional to its input voltage U2, when the voltage connected to the test load decreases (that is, the voltage drops), the input voltage U2 of fan 2 also changes accordingly, thereby achieving adaptive adjustment of air volume with voltage.

[0027] Furthermore, the core of the wind turbine resistance unit RA is composed of multiple cement resistors R1...RN with the same resistance value. The cement resistors are connected in series to evenly divide the input voltage U2 to support high-power operation.

[0028] Each cement resistor is equipped with a diode D, a varistor RN, and a capacitor C. The varistor RN is connected in series with the capacitor C and then in parallel across the cement resistor. The diode D is connected in parallel across the varistor RN, with its conduction direction pointing toward terminal X2. When a spike voltage caused by an abnormality in wind turbine 2 flows back into the wind turbine resistor unit RA, the spike voltage flows through the diode D into the capacitor C, where it is absorbed. During this time, the resistance of the varistor RN increases, providing protection.

[0029] The wind turbine resistance unit RA is also provided with a bidirectional thyristor SCR with a withstand voltage level of 4000V and above. The bidirectional thyristor SCR is connected in parallel at both ends of the wind turbine resistance unit RA, and its controlled end is connected to an external controller. The controller can control the input of the fan 2 to form chopping by driving the bidirectional thyristor SCR on and off, and then forcibly control the input voltage of the fan 2 through the duty cycle principle to achieve controllable air volume.

[0030] Furthermore, the terminal X1, the terminal X2, the wind turbine resistance unit RA, and each tubular high-power resistor RB are connected via a copper busbar.

[0031] Furthermore, the housing 11 of the load group 1 is externally connected to the ground, thereby performing grounding protection.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An air volume adaptive test load, comprising a load group, a fan, a terminal X1, and a terminal X2, wherein the fan blows air toward the load group, and is characterized in that: The load group includes a fan resistance unit RA and a tubular high-power resistor RB. Terminal X1 is connected in series with the fan resistance unit RA and the tubular high-power resistor RB and then connected to terminal X2. The input end of the fan is connected to the two ends of the fan resistance unit RA. The total resistance of the fan resistance unit RA is such that when the test load is operating at the maximum allowable voltage, the voltage U2 obtained by dividing the fan resistance unit RA is consistent with the rated voltage of the fan. The wind turbine resistance unit RA is composed of multiple cement resistors with the same resistance value connected in series. Each cement resistor is provided with a diode D, a varistor RN and a capacitor C. The varistor RN is connected in series with the capacitor C and then connected in parallel to the two ends of the cement resistor. The diode D is connected in parallel to the two ends of the varistor RN with the conduction direction pointing to the terminal X2. The wind turbine resistance unit RA also includes a bidirectional thyristor SCR, which is connected in parallel to the two ends of the wind turbine resistance unit RA, and its controlled end is connected to an external controller.

2. The air volume adaptive test load according to claim 1, characterized in that: The voltage resistance of the bidirectional thyristor SCR is 4000V or above.

3. The air volume adaptive test load according to claim 1, characterized in that: There are multiple tubular high-power resistors RB, which are connected in series to be suitable for high power.

4. The air volume adaptive test load according to claim 1 or 3, characterized in that: The terminal X1, the terminal X2, the fan resistance unit RA, and the tubular high-power resistor RB are connected through a copper busbar.

5. The air volume adaptive test load according to claim 1, characterized in that: The load group has a housing externally connected to the ground, and the wind turbine resistance unit RA and the tubular high-power resistor RB are located in the housing; It also includes terminal d and terminal b for connecting to the fan input end. Terminal d and terminal b are respectively connected to the two ends of the fan resistance unit RA. Terminal X1, terminal d, terminal b, and terminal X2 extend out of the shell.

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