Circuit for half-wave and full-wave testing and testing device

Abstract

The utility model relates to a circuit for half-wave and full-wave testing and a testing device. The circuit used for the half-wave and full-wave test comprises a first wiring unit used for being externally connected with power conversion equipment; the second wiring unit is used for externally connecting a load; the control unit is respectively connected with the first wiring unit and the second wiring unit and is used for controlling the circuit to work in a half-wave test state or a full-wave test state; wherein the control unit comprises a control circuit comprising a relay unit or a control circuit comprising a controllable semiconductor device, so that the technical problem that the test efficiency is affected due to the fact that frequent disassembly is needed in the test process in the prior art is solved, and the technical effects of avoiding frequent disassembly in the test process and improving the test efficiency and safety are achieved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular, to a circuit and a test device for half-wave and full-wave tests. Background Art

[0002] The development of power electronics technology has introduced new types of loads: half-wave loads. Half-wave load appliances refer to appliances that only operate on the positive half-cycle of the power supply rail, and their loads are the endpoints of the power supply rail. For example, LED lights, half-wave power supplies, and small motors. Since the working cycle of these half-wave loads is only half of the sine wave, and in daily life, ordinary loads and half-wave loads coexist in household appliances, in the design of inverters, their AC output should be capable of driving both full-wave and half-wave loads simultaneously. However, during the inverter development stage, existing half-wave devices are relatively simple. When conducting half-wave load tests, the half-wave device needs to be independently connected in series between the inverter and the load. When conducting full-wave load tests, the power needs to be cut off to remove the half-wave device and reconnect the inverter and the load, and then power on again for testing. The testing process is relatively cumbersome, seriously reducing work efficiency.

[0003] In response to the above problems, no effective solution has been proposed yet. Summary of the Utility Model

[0004] Embodiments of this application provide a circuit and a test device for half-wave and full-wave tests, so as to at least solve the technical problem that frequent disassembly is required during the testing process in related technologies, which affects the testing efficiency.

[0005] According to one aspect of the embodiments of this application, a circuit for half-wave and full-wave tests is provided, including: a first wiring unit for externally connecting a power conversion device; a second wiring unit for externally connecting a load; a control unit respectively connected to the first wiring unit and the second wiring unit, for controlling the circuit to operate in a half-wave test state or a full-wave test state; wherein, the control unit includes a control circuit including a relay unit or a control circuit including a controllable semiconductor device.

[0006] Optionally, the control circuit including a relay unit includes: a relay unit, a power diode, a relay control power supply, and a control switch; wherein: the first end of the relay unit is connected to the negative pole of the relay control power supply; the second end of the relay unit is connected to the second end of the control switch; the positive pole of the relay control power supply is connected to the first end of the control switch; the common end after the third end of the relay unit is connected to the positive pole of the power diode is connected to the first wiring unit; the common end after the fourth end of the relay unit is connected to the negative pole of the power diode is connected to the second wiring unit.

[0007] Optionally, the control circuit including the controllable semiconductor device includes: a sampling circuit configured to collect the voltage waveform output by the power conversion device and convert the voltage waveform into a target signal; a driving circuit connected to the sampling circuit, configured to drive the controllable semiconductor device to be always turned on through a preset pulse width modulation signal, or generate a pulse width modulation signal based on the target signal to drive the turning on and off of the controllable semiconductor device.

[0008] Optionally, the driving circuit includes: a DSP chip, a capacitor, a diode, a first resistor, a second resistor, a third resistor, and a controllable semiconductor device; wherein: the I / O port of the DSP chip is configured to access the sampling circuit; the power supply port of the DSP chip is configured to access a power supply; the signal output port of the DSP chip is respectively connected to the first end of the capacitor, the negative electrode of the diode, and the first end of the third resistor, and the second end of the capacitor is configured to be grounded; the second end of the third resistor is respectively connected to the first end of the first resistor and the second end of the second resistor, and the first end of the second resistor is connected to the positive electrode of the diode; the second end of the first resistor is connected to the control end of the controllable semiconductor device; the input end of the controllable semiconductor device is connected to the first wiring unit, and the output end of the controllable semiconductor device is connected to the second wiring unit.

[0009] Optionally, the sampling circuit includes: a fourth resistor, a fifth resistor, and an amplifier; wherein: the fifth resistor is connected to the first wiring unit; the non-inverting input terminal and the inverting input terminal of the amplifier are respectively connected to both ends of the fifth resistor; the output terminal of the amplifier is connected to the driving circuit; the first end of the fourth resistor is connected to the output terminal of the amplifier, and the second end of the fourth resistor is connected to the non-inverting input terminal of the amplifier.

[0010] Optionally, the controllable semiconductor device includes a semi-controlled device or a fully-controlled device.

[0011] Optionally, the power conversion device includes an inverter or a three-phase AC output device.

[0012] According to another aspect of the embodiments of the present application, a testing device is provided, including: a testing circuit, a metal heat sink, and a printed circuit board; wherein: the printed circuit board is fixedly arranged above the metal heat sink; the circuit components of the testing circuit are soldered on the printed circuit board, and the testing circuit includes the circuit for half-wave and full-wave testing as described above.

[0013] Optionally, a heat dissipation layer is provided between the metal heat sink and the printed circuit board.

[0014] Optionally, the heat dissipation material of the heat dissipation layer includes heat dissipation silicone grease.

[0015] In the embodiment of the present application, the circuit for half-wave and full-wave testing mainly consists of a first wiring unit, a second wiring unit, and a control unit. Among them, the first wiring unit is used to externally connect a power conversion device; the second wiring unit is used to externally connect a load; the control unit is respectively connected to the first wiring unit and the second wiring unit, and is used to control the circuit to work in a half-wave testing state or a full-wave testing state; wherein, the control unit includes a control circuit containing a relay unit or a control circuit containing a controllable semiconductor device, thereby solving the technical problem that frequent disassembly is required during the testing process in the related art, which affects the testing efficiency, and achieving the technical effect of avoiding frequent disassembly during the testing process, improving the testing efficiency and safety. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other embodiments can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Schematic diagram of the circuit for half-wave and full-wave testing provided by the embodiment of the present application;

[0018] Figure 2 Schematic diagram of a circuit for half-wave and full-wave testing provided by an alternative embodiment of the present application;

[0019] Figure 3 Schematic diagram of another circuit for half-wave and full-wave testing provided by an alternative embodiment of the present application;

[0020] Figure 4 Schematic diagram of the specific classification of the testing device provided by an alternative embodiment of the present application;

[0021] Figure 5 Schematic diagram of the 3D model of the single-phase half-wave testing device provided by an alternative embodiment of the present application;

[0022] Figure 6 Schematic diagram of the test results using the single-phase half-wave testing device provided by an alternative embodiment of the present application. Detailed Embodiments

[0023] Embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present application are shown in the drawings, it should be understood that the embodiments of the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the embodiments of the present application. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes and are not used to limit the protection scope of the present application.

[0024] According to one aspect of the embodiments of the present application, a circuit for half-wave and full-wave testing is provided. Figure 1 The schematic diagram of the circuit for half-wave and full-wave testing provided by the embodiments of the present application is as Figure 1 shown. The circuit for half-wave and full-wave testing includes: a first wiring unit 11, a second wiring unit 12, and a control unit 13; wherein:

[0025] The first wiring unit 11 is used to externally connect a power conversion device; the second wiring unit 12 is used to externally connect a load; the control unit 13 is respectively connected to the first wiring unit 11 and the second wiring unit 12, and is used to control the circuit to work in a half-wave testing state or a full-wave testing state; wherein, the control unit 13 includes a control circuit including a relay unit or a control circuit including a controllable semiconductor device.

[0026] The circuit design for half-wave and full-wave testing aims to simplify the testing process of inverters or three-phase AC output devices, especially when evaluating their adaptability to half-wave and full-wave loads. The circuit includes a first wiring unit, a second wiring unit, and a control unit, which are respectively used to connect a power conversion device, a load, and to achieve the switching of the testing state.

[0027] The first wiring unit is used to connect a power conversion device, such as the output terminal of an inverter. This unit ensures a safe and reliable electrical connection between the circuit for half-wave and full-wave testing and the power conversion device. The second wiring unit is used to connect a test load, which can be an analog load, an actual electrical appliance, or any device that needs to be tested. Through the second wiring unit, the circuit for half-wave and full-wave testing can accurately reflect the interaction between the load and the power conversion device in the half-wave or full-wave state. The control unit is the core of the test circuit, and it includes a mechanism for switching between the half-wave and full-wave testing states, and there are two main implementation methods:

[0028] A control circuit including a relay unit: Using a relay as a switch, the switching between half-wave and full-wave testing is achieved by controlling the on-off state of the relay. When the relay is closed, the circuit works in the full-wave testing state; when the relay is open, combined with the function of the power diode, the circuit works in the half-wave testing state.

[0029] Control circuit including controllable semiconductor devices: Utilizing the characteristics of fully controlled devices (such as IGBTs, MOSFETs) or semi-controlled devices (such as thyristors), through a DSP chip or other control logics, PWM signals are generated to control the conduction and turn-off of the devices, thereby achieving the conversion between half-wave and full-wave test states. This method provides higher control precision and flexibility.

[0030] In an embodiment of the present application, through a unified circuit for half-wave and full-wave tests, there is no need to frequently disassemble and assemble equipment between half-wave and full-wave tests, improving the test efficiency and reducing the risk of human errors. Whether using relays or controllable semiconductor devices, this circuit for half-wave and full-wave tests can adapt to a wide range of load types and test requirements, increasing the diversity of test schemes. Especially when using controllable semiconductor devices, through precise PWM control, fine adjustment of the output waveform can be achieved, ensuring the accuracy and repeatability of test results.

[0031] As an alternative embodiment, the control circuit including a relay unit includes: a relay unit, a power diode, a relay control power supply, and a control switch; wherein:

[0032] The first end of the relay unit is connected to the negative pole of the relay control power supply; the second end of the relay unit is connected to the second end of the control switch; the positive pole of the relay control power supply is connected to the first end of the control switch; the common end after the third end of the relay unit is connected to the positive pole of the power diode is connected to the first wiring unit; the common end after the fourth end of the relay unit is connected to the negative pole of the power diode is connected to the second wiring unit.

[0033] The relay unit includes an electromagnetic coil and one or more groups of contacts (normally open contacts or normally closed contacts). When the electromagnetic coil is energized, a magnetic field is generated, attracting or releasing the contact mechanism to make the contacts close or open.

[0034] The power diode is a diode that can withstand large currents and high voltages, mainly used for rectifying or protecting the circuit to prevent reverse current flow.

[0035] The relay control power supply provides the voltage and current required for the operation of the relay's electromagnetic coil, usually a stable DC power supply.

[0036] The control switch can be a manual switch, a sensor, a switch signal output by a controller, etc., used to control the on and off of the relay coil.

[0037] In an embodiment of the present application, the relay unit, as a mechanical switch, can provide electrical isolation between the control circuit and the main circuit, protecting the control circuit from the high voltage or large current of the main circuit. By controlling the switch, the on / off of large current or high voltage can be remotely or automatically controlled, which is suitable for automation control scenarios. The power diode can prevent the reverse current in the main circuit from damaging the relay or the control circuit, increasing the reliability of the circuit.

[0038] Figure 2 The following is a schematic diagram of a circuit for half-wave and full-wave tests provided by an alternative embodiment of the present application. As Figure 2 shown, it is connected in series between an inverter (a three-phase AC output device) and a load, and mainly includes a first wiring unit, a half-wave control circuit unit (corresponding to the above control unit), and a second wiring unit. The first wiring unit and the second wiring unit are mainly used to connect the device under test and the load. The half-wave control circuit unit includes relay units RY1-RY3, power diodes D1-D3, a relay control power supply Vdc, and a control switch S.

[0039] The circuit for half-wave and full-wave tests has low cost and simple operation. There is no restriction on the type of relay and no restriction on the control voltage of the relay, which has a certain degree of flexibility. In addition, the circuit for half-wave and full-wave tests can be applied to single-phase test circuits and is also suitable for three-phase test circuits. Its application range is wide and the application prospect is good.

[0040] As an alternative embodiment, the control circuit including a controllable semiconductor device includes: a sampling circuit for collecting the voltage waveform output by the power conversion device and converting the voltage waveform into a target signal; a driving circuit connected to the sampling circuit for driving the controllable semiconductor device to always remain on through a preset pulse width modulation signal, or generating a pulse width modulation signal based on the target signal to drive the on / off of the controllable semiconductor device.

[0041] The above driving circuit is a key part for controlling the on / off state of the controllable semiconductor device (such as IGBT, MOSFET, etc.). In the specific implementation, the driving circuit mainly includes a DSP chip (digital signal processor), a capacitor, a diode, three resistors, and a controllable semiconductor device.

[0042] The above sampling circuit is responsible for monitoring the output voltage of the power conversion device and converting the voltage waveform into a signal recognizable by the DSP chip.

[0043] In an embodiment of the present application, by controlling the switch of the controllable semiconductor device through a PWM signal, the fine adjustment of the output of the power conversion device is realized, and the response speed and control accuracy of the circuit are improved.

[0044] As an alternative embodiment, the drive circuit includes: a DSP chip, a capacitor, a diode, a first resistor, a second resistor, a third resistor, and a controllable semiconductor device; wherein:

[0045] The I / O port of the DSP chip is used to access the sampling circuit; the power port of the DSP chip is used to access the power supply; the signal output port of the DSP chip is respectively connected to the first end of the capacitor, the negative electrode of the diode, and the first end of the third resistor, and the second end of the capacitor is used to ground; the second end of the third resistor is respectively connected to the first end of the first resistor and the second end of the second resistor, and the first end of the second resistor is connected to the positive electrode of the diode; the second end of the first resistor is connected to the control end of the controllable semiconductor device; the input end of the controllable semiconductor device is connected to the first wiring unit, and the output end of the controllable semiconductor device is connected to the second wiring unit.

[0046] The I / O port of the DSP chip receives signals from the sampling circuit, and the power port is directly powered by an external power supply. Inside the DSP chip, the generation of PWM (pulse width modulation) signals is realized through programming, and this signal is output from the signal output port to control the switching state of the controllable semiconductor device.

[0047] The capacitor is connected between the signal output port of the DSP chip and the ground to filter out high-frequency noise in the PWM signal and ensure the purity of the signal.

[0048] The diode is used to prevent reverse current from passing through the DSP chip and protect the DSP from reverse voltage impact.

[0049] The three resistors (the first, second, and third resistors) form a voltage division network and a current limiting circuit. The first resistor is directly connected to the control end of the controllable semiconductor device to limit the drive current and avoid damaging the controllable semiconductor device; the second and third resistors are used for voltage division to ensure that the PWM signal output by the DSP chip can be correctly transmitted to the control end of the controllable semiconductor device.

[0050] Under the control of the PWM signal, the controllable semiconductor device switches between the on and off states to achieve the control of the output of the power conversion device.

[0051] In the embodiment of the present application, the diode and the resistor network provide basic overload protection to prevent damage to the DSP chip and the controllable semiconductor device in abnormal situations.

[0052] As an alternative embodiment, the sampling circuit includes: a fourth resistor, a fifth resistor, and an amplifier; wherein:

[0053] The fifth resistor is connected to the first wiring unit; the non-inverting input terminal and the inverting input terminal of the amplifier are respectively connected to both ends of the fifth resistor; the output terminal of the amplifier is connected to the drive circuit; the first end of the fourth resistor is connected to the output terminal of the amplifier, and the second end of the fourth resistor is connected to the non-inverting input terminal of the amplifier.

[0054] The two resistors, namely the fourth resistor and the fifth resistor, form a voltage dividing network for reducing the high voltage output by the power conversion device to a safe range for subsequent processing.

[0055] The non-inverting input terminal of the amplifier receives the voltage signal after voltage division, the inverting input terminal is usually connected to the reference ground, and the output terminal of the amplifier transmits the amplified voltage signal to the DSP chip of the drive circuit for the DSP chip to analyze and process.

[0056] In the embodiment of the present application, through voltage division and amplification processing, the sampling circuit ensures that the DSP chip can accurately obtain the actual output state of the power conversion device, so as to make corresponding control decisions.

[0057] Figure 3 Another schematic diagram of a circuit for half-wave and full-wave tests provided for an optional embodiment of the present application is as Figure 3 shown. The circuit for half-wave and full-wave tests mainly includes a DSP chip, a capacitor C1, resistors R1 - R5, a fully controlled device Q1, an amplifier G, and a diode D1, where R5 is a sampling resistor. When using a fully controlled device, an external drive circuit is required. When working in the full-wave mode, the DSP chip issues an instruction to keep the fully controlled device Q1 always in the on state; when working in the half-wave state, after the sampling circuit collects the voltage waveform output by the inverter, it is converted into a signal recognizable by the DSP chip through the amplifier. The DSP chip outputs a PWM wave according to the collected data signal to control the on and off of the fully controlled device Q1, so that the output waveform is a half-wave. Compared with a relay + power diode, it can control whether the output is a positive half-wave or a negative half-wave, and even can intercept the output of the desired waveform according to needs.

[0058] As an optional embodiment, the controllable semiconductor device includes a semi-controlled device or a fully controlled device.

[0059] The controllable semiconductor device can control the flow of current.

[0060] For example, a thyristor is a typical semi-controlled device. After it conducts under a forward voltage, even if the gate loses the trigger signal, as long as the load current remains above the holding current, the thyristor will continue to conduct until the current flowing through it drops below the holding current. A thyristor is composed of four layers of semiconductor materials, forming a PNPN structure, and has an anode, a cathode, and a gate. The gate is used to trigger the conduction of the thyristor. Once it conducts, the thyristor will continue to conduct until the current drops below the holding current.

[0061] For another example, both the insulated gate bipolar transistor (IGBT) and the metal oxide semiconductor field effect transistor (MOSFET) are fully controlled devices, and their conduction or cutoff can be controlled by signals at the gate (or grid), without relying on the load current. The IGBT combines the high input impedance of the MOSFET and the large current handling capacity of the bipolar transistor, and is suitable for high voltage and large current applications. The MOSFET has a fast switching speed and high efficiency, and is suitable for high-frequency switching power supplies and low-power applications.

[0062] In the embodiments of the present application, the fully controlled device allows for precise control of the opening and closing of the current through the gate signal, improving the controllability and response speed of power electronic devices. The fast switching ability of the fully controlled device reduces switching losses and improves conversion efficiency, helping to reduce energy consumption.

[0063] As an alternative embodiment, the power conversion device includes an inverter or a three-phase AC output device.

[0064] The above-mentioned power conversion device generally refers to a device that can convert electrical energy from one form to another, including but not limited to inverters and three-phase AC output devices.

[0065] Among them, an inverter is a power conversion device that converts direct current (DC) to alternating current (AC), and is widely used in scenarios such as solar photovoltaic systems, uninterruptible power supplies (UPS), electric vehicle charging infrastructure, and industrial control. In the specific implementation, the inverter may include the following components: a DC input interface: used to connect a DC power source, such as a battery pack or a photovoltaic array. A power electronics module: containing fully controlled devices such as IGBTs and MOSFETs, used to perform power conversion. A control circuit: usually based on a DSP (Digital Signal Processor) or a microcontroller, used to control the inversion process, including but not limited to the generation of PWM signals. An AC output interface: used to connect a load or the power grid and output the converted alternating current.

[0066] Three-phase AC output devices generally refer to devices that can generate three-phase alternating current. Such devices can be generators, inverters, drivers, or specific power supply units. In specific embodiments, the key components of a three-phase AC output device include: Power module: Used to generate or regulate three-phase alternating current, which may include an inverter or modulation circuit. Control logic: Used to monitor and adjust the output frequency, voltage, and current to ensure compliance with load requirements. Protection circuit: Includes overload protection, short-circuit protection, and under-voltage protection, etc., to ensure the safe operation of the device.

[0067] According to another aspect of the embodiments of the present application, a test device is provided, including: a test circuit, a metal heat sink, and a printed circuit board; wherein: The printed circuit board is fixedly arranged above the metal heat sink; The circuit components of the test circuit are soldered on the printed circuit board, and the test circuit includes the circuit for half-wave and full-wave tests as described above.

[0068] The above test circuit is a circuit composed of a series of components, used to test the output performance of the inverter in two modes: half-wave and full-wave. Half-wave and full-wave tests respectively refer to test methods that only test the waveform of half a cycle and the complete cycle of the inverter output, used to evaluate the adaptability and performance of the inverter to different types of loads. The test circuit is the core part of the test device, containing circuit components for realizing half-wave and full-wave test functions. These components may include, but are not limited to, fully controlled devices (such as IGBTs, MOSFETs), semi-controlled devices (such as thyristors), relays, power diodes, control circuits (including drive circuits, recovery circuits), and necessary sensors and signal processing components.

[0069] The metal heat sink is used to improve the heat dissipation efficiency of the power devices in the test circuit. The heat sink is usually made of a metal with good thermal conductivity (such as aluminum, copper), and can be flat, finned, or have other structures, aiming to increase the surface area to promote heat exchange.

[0070] The printed circuit board serves as a platform for carrying and connecting all components in the test circuit. The printed circuit board is arranged with preset copper lines for electrical connection of each component, and provides mechanical support to ensure stable contact between components.

[0071] The printed circuit board is installed above the metal heat sink through fixing devices (such as screws, clamps) to ensure good thermal contact. The components of the test circuit are soldered on the printed circuit board, and the back of the power devices (such as IGBTs, MOSFETs) is directly in contact with the heat sink, and heat dissipation silicone grease may be applied in the middle to improve the heat conduction efficiency.

[0072] Sensors and signal processing components (such as DSP chips, amplifiers) are also integrated on the printed circuit board, and together with the power devices, they form a complete test circuit.

[0073] In an embodiment of the present application, by fixing the printed circuit board above the metal radiator, the heat generated by the test circuit can be effectively conducted to the radiator quickly and then dissipated into the surrounding environment through the radiator, thus avoiding overheating of components and extending the service life of the test device. Integrating all components on a single printed circuit board and designing it integrally with the radiator not only saves space but also improves the integration and reliability of the device. The test circuit can switch between half-wave and full-wave test modes according to instructions, is applicable to various types of load tests, and improves the test efficiency and the applicable range of the device.

[0074] As an alternative embodiment, a heat dissipation layer is provided between the metal radiator and the printed circuit board; wherein, the heat dissipation material of the heat dissipation layer includes thermal grease.

[0075] The above thermal grease is also known as heat-conducting paste or thermal interface material, and is used to fill the tiny gaps between the heat-generating components (such as power devices including power diodes) and the metal radiator, improve the thermal contact between the two, and reduce the thermal resistance.

[0076] Apply a thin layer of thermal grease evenly on the back of the heat-generating component, and press the metal radiator tightly against the heat-generating component coated with thermal grease to ensure good contact.

[0077] In an embodiment of the present application, the thermal grease can fill the uneven surfaces, reduce the air gaps, and improve the heat transfer efficiency from the heat-generating component to the radiator. Through effective heat conduction, it helps the heat-generating component maintain a lower working temperature, extends the service life, and improves the device stability. It avoids damage to electronic components caused by overheating and extends the overall service life of the device.

[0078] Figure 4 Schematic diagram of the specific classification of the test device provided for an alternative embodiment of the present application, as Figure 4 shown, the test device uses a power diode and a relay, but is not limited to these two devices. The power diode can be replaced with a semi-controlled device, such as a thyristor; or it can be replaced with a fully-controlled device, such as an IGBT. When replaced with these types of devices, the corresponding relay control circuit can be replaced with the control circuit (including the drive circuit and the recovery circuit) of the fully-controlled device (semi-controlled device), and its on and off are controlled through a PWM signal, thereby controlling the test device to work in the half-wave test and full-wave test states.

[0079] For the control circuit (including the drive circuit and the recovery circuit), its voltage source is not limited. It can either use an external power supply or directly take power from the AC output side of the inverter. For example, the control circuit is a 220V / 380V relay, and it can also be driven by a DC voltage of 12V after passing through a rectification circuit and a buck circuit.

[0080] Figure 5 This is a schematic diagram of the 3D model of the single-phase half-wave test device provided by an alternative embodiment of the present application. As Figure 5 shown, the test device is connected between L1 and N. The selected relay RY1 is controlled by a 12V voltage, and its 12V power supply uses a simple external power supply. The half-wave device power diode D1 is connected in series in the power loop L1. Its circuit components are soldered on the PCB board, and the PCB board is fixed above the metal radiator. The power device should be in direct contact with the radiator. To improve the heat dissipation efficiency, a high-efficiency heat dissipation material, such as thermal grease, can be applied between the back of the power device and the radiator.

[0081] Connect the connection lines L1 and N to the inverter and the load, and power on the inverter. A normally open relay is used. At this time, the output side of the test device is a half-sine wave, and the corresponding load is a half-wave load. Press the control switch, the relay RY1 is attracted, and the power diode D1 is short-circuited. At this time, the sinusoidal alternating current all flows into the load through the relay, and the test device works in the full-wave test state. If a normally closed relay is used, the test condition is opposite.

[0082] Figure 6 This is a schematic diagram of the test results using the single-phase half-wave test device provided by an alternative embodiment of the present application. As Figure 6 shown, taking the sine wave as an example, the waveform pointed by arrow ① is the full-wave waveform output by the inverter, and the waveform pointed by arrow ② is the half-wave waveform output by the half-wave test device. This test device has good test effects and convenient operation steps, greatly improving the test efficiency.

[0083] For the sake of description, spatial relative terms, such as "above", "on top of", "on the upper surface", "above-mentioned", etc., can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "on top of other devices or structures" will be positioned as "below other devices or structures" or "beneath other devices or structures" afterwards. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0084] In addition, it should be noted that using words such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above words have no special meanings, and thus cannot be understood as limiting the protection scope of the present application.

[0085] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A circuit for half-wave and full-wave testing, characterized in that: include: A first wiring unit, used for connecting an external power conversion device; The second wiring unit is used for connecting an external load; A control unit, connected to the first wiring unit and the second wiring unit respectively, for controlling the circuit to operate in a half-wave test state or a full-wave test state; Wherein, the control unit includes a control circuit including a relay unit or a control circuit including a controllable semiconductor device.

2. The circuit for half-wave and full-wave testing according to claim 1, characterized in that: The control circuit including the relay unit includes: a relay unit, a power diode, a relay control power supply and a control switch; wherein: The first end of the relay unit is connected to the negative electrode of the relay control power supply; The second end of the relay unit is connected to the second end of the control switch; The positive electrode of the relay control power supply is connected to the first end of the control switch; A common end of the third end of the relay unit connected to the anode of the power diode is connected to the first wiring unit; A common end of the fourth end of the relay unit connected to the cathode of the power diode is connected to the second wiring unit.

3. The circuit for half-wave and full-wave testing according to claim 1, characterized in that: The control circuit including the controllable semiconductor device comprises: A sampling circuit, used for collecting the voltage waveform output by the power conversion device and converting the voltage waveform into a target signal; The driving circuit is connected to the sampling circuit and is used to drive the controllable semiconductor device to always remain on through a preset pulse width modulation signal, or to generate a pulse width modulation signal based on the target signal to drive the controllable semiconductor device to be turned on and off.

4. The circuit for half-wave and full-wave testing according to claim 3, characterized in that: The driving circuit comprises: a DSP chip, a capacitor, a diode, a first resistor, a second resistor, a third resistor and a controllable semiconductor device; wherein: The I / O port of the DSP chip is used to access the sampling circuit; The power port of the DSP chip is used to access the power supply; The signal output port of the DSP chip is respectively connected to the first end of the capacitor, the cathode of the diode and the first end of the third resistor, and the second end of the capacitor is used for grounding; The second end of the third resistor is connected to the first end of the first resistor and the second end of the second resistor respectively, and the first end of the second resistor is connected to the anode of the diode; The second end of the first resistor is connected to the control end of the controllable semiconductor device; The input end of the controllable semiconductor device is connected to the first wiring unit, and the output end of the controllable semiconductor device is connected to the second wiring unit.

5. The circuit for half-wave and full-wave testing according to claim 3, characterized in that: The sampling circuit comprises: a fourth resistor, a fifth resistor and an amplifier; wherein: The fifth resistor is connected to the first wiring unit; The non-inverting input terminal and the inverting input terminal of the amplifier are respectively connected to the two ends of the fifth resistor; The output end of the amplifier is connected to the driving circuit; A first end of the fourth resistor is connected to the output end of the amplifier, and a second end of the fourth resistor is connected to the non-inverting input end of the amplifier.

6. The circuit for half-wave and full-wave testing according to claim 1, characterized in that: The controllable semiconductor device includes a half-controlled device or a fully-controlled device.

7. The circuit for half-wave and full-wave testing according to claim 1, characterized in that: The power conversion device includes an inverter or a three-phase AC output device.

8. A testing device, characterized in that: include: Test circuit, metal heat sink and printed circuit board; wherein: The printed circuit board is fixedly arranged above the metal heat sink; Circuit components of the test circuit are soldered on the printed circuit board, and the test circuit includes a circuit for half-wave and full-wave testing as described in any one of claims 1 to 7.

9. The testing device according to claim 8, characterized in that: A heat dissipation layer is arranged between the metal heat sink and the printed circuit board.

10. The testing device according to claim 9, characterized in that: The heat dissipation material of the heat dissipation layer includes heat dissipation silicone grease.

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