A method for controlling the flash waveform of a solar simulator by combining a discharge network with an IGBT

Abstract

The invention discloses a method for controlling a flash waveform of a solar simulator by combining a discharge network with an IGBT. The method combines the technology of pulse discharge of a xenon lamp with an inductor-capacitor network, adopts a PID control algorithm, and performs light feedback. The input of the PID controller is the difference between the feedback light intensity and the set light intensity. The difference is calculated by PID to obtain a control signal. The control signal is connected to the G terminal and the E terminal of the IGBT to control the on-resistance of the IGBT. The controllable resistance of the IGBT changes the impedance of the discharge circuit, thereby changing the voltage and current at both ends of the xenon lamp. The IGBT control method of the light intensity waveform of the solar simulator of the invention adopts feedback adjustment technology, utilizes the PID controller to perform intelligent automatic adjustment on the IGBT switch element, and the inductor-capacitor network discharges two parallel xenon lamps. Both xenon lamps have the above-mentioned IGBT control circuit, and the light intensity of the discharge flash of the two xenon lamps is independently controlled, thereby effectively ensuring the luminous stability of the solar simulator.

Description

Technical Field

[0001] The invention relates to the technical field of IGBTs, in particular to a method for controlling a flash waveform of a solar simulator by combining a discharge network with an IGBT. Background Art

[0002] The photovoltaic industry has increasingly higher requirements for solar simulators, one of which is a long-term instability index requirement of less than 1%. The most commonly used flash solar simulator in the photovoltaic industry uses capacitor energy storage as the basic power supply method for the light source. The energy in the capacitor is discharged by a thyristor switch and discharged through a light source such as a xenon lamp to produce a flash. The general technology in the original industry is to use energy storage capacitors combined with light intensity feedback control technology. This technology requires high-power current and voltage control components to be connected in series with the xenon lamp, because the instantaneous power of the xenon lamp discharge can reach tens of thousands of watts or even hundreds of thousands of watts; another technology is to use an inductor-capacitor network (LC network) to discharge the xenon lamp and emit a discharge waveform close to a square wave to control the stability of the light intensity. The instability is about 2%. The above two technologies have their own advantages and disadvantages. The first technology has high light intensity stability, but requires high-power current and voltage control components, generally a large number of MOS tubes are connected in parallel, which is very costly, and a large amount of energy is consumed in the current and voltage control components during the discharge process, and the discharge efficiency is very low; although the second technology avoids the shortcomings of the first technology, the stability of controlling light intensity is poor. In order to achieve higher indicators, this patent proposes a method of combining an inductor-capacitor network with an IGBT to discharge and control light stability. Summary of the invention

[0003] The purpose of the present invention is to combine the technology of pulse discharge of xenon lamp with inductor and capacitor network, and provide a method of controlling the flash waveform of solar simulator with IGBT in combination with discharge network, so as to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for controlling the flash waveform of a solar simulator by combining a discharge network with an IGBT adopts a PID control algorithm for light feedback. The input of the PID controller is the difference between the feedback light intensity and the set light intensity. The difference is calculated by PID to obtain a control signal. The control signal is connected to the G and E terminals of the IGBT to control the on-resistance of the IGBT. The controllable resistance of the IGBT changes the impedance of the discharge circuit, thereby changing the voltage and current at both ends of the xenon lamp.

[0006] As a further solution of the present invention: a subtractor is connected to the front end of the PID controller.

[0007] As a further solution of the present invention: the back end of the PID controller is connected with an IGBT.

[0008] As a further solution of the present invention: the C terminal and the E terminal of the IGBT are connected to a discharge circuit of a capacitor.

[0009] As a further solution of the present invention: the discharge circuit is an electrical circuit of a xenon lamp.

[0010] As a further solution of the present invention: a reference battery is used to pick up the waveform of the luminous intensity.

[0011] As a further solution of the present invention: the inputs of the subtractor are respectively the feedback light intensity and the set light intensity.

[0012] Compared with the prior art, the beneficial effects of the present invention are: the IGBT control method of the solar simulator light intensity waveform of the present invention adopts feedback regulation technology and uses a PID controller to perform intelligent automatic regulation on the IGBT switch element, thereby effectively ensuring the luminous stability of the xenon lamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is an overall schematic diagram of the present invention.

[0014] Figure 2 It is a schematic diagram of an embodiment of the present invention.

[0015] Figure 3 It is a square wave shape diagram of the discharge light intensity.

[0016] Figure 4 This is the long-term instability curve of the discharge light intensity after the IGBT control is released. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] See also Figure 1 Embodiment 1: In the embodiment of the present invention, a method for controlling the flash waveform of a solar simulator by combining a discharge network with an IGBT adopts a PID control algorithm, uses a reference battery to pick up the waveform of the luminous intensity, and performs light feedback. The input of the PID controller is the difference between the feedback light intensity and the set light intensity. The difference is calculated by PID to obtain a control signal. The control signal is connected to the G and E terminals of the IGBT to control the on-resistance of the IGBT. The C and E terminals of the IGBT are connected to the discharge circuit of the capacitor. The discharge circuit is composed of a storage capacitor, an inductor, and a xenon lamp. The controllable resistance of the IGBT improves the impedance of the discharge circuit, thereby changing the voltage and current at both ends of the xenon lamp to achieve stable discharge of the xenon lamp.

[0019] The following design is made when the above control method is specifically implemented. Generally, there are two xenon lamps in the solar simulator, and the two xenon lamps are connected in parallel to the inductor and capacitor network. The above control circuit designed by the present invention has two sets, which control the discharge of the two xenon lamps respectively. Figure 2 In this way, the light intensity of each xenon lamp can be independently controlled to ensure the stability of the xenon lamp discharge flash intensity, thereby ensuring the stability of the simulated sunlight flash of the solar simulator.

[0020] The discharge of the xenon lamp by the inductor-capacitor network (LC network) is close to a square wave, but the long-term instability (LTI) of the square wave is generally around 2%. The square wave shape of the discharge light intensity is as follows: Figure 3 On this basis, after using IGBT to control the discharge, the long-term instability of the discharge light intensity can be greatly improved to less than 0.5%. Figure 4 Embodiment 2: Based on Embodiment 1, the IGBT used in this design can be replaced by other switching elements with the same regulating function.

[0021] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0022] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for controlling the flash waveform of a solar simulator by combining a discharge network with an IGBT, characterized in that: A PID control algorithm is used for light feedback. The input of the PID controller is the difference between the feedback light intensity and the set light intensity. The difference is calculated by PID to obtain a control signal. The control signal is connected to the G and E terminals of the IGBT to control the on-resistance of the IGBT. The controllable resistance of the IGBT changes the impedance of the discharge circuit, thereby changing the voltage and current at both ends of the xenon lamp. The C and E terminals of the IGBT are connected to the discharge circuit of the capacitor. The discharge circuit is the electrical circuit of the xenon lamp. A reference battery is used to pick up the waveform of the luminous light intensity.

2. A method for controlling a solar simulator flash waveform by combining a discharge network with an IGBT according to claim 1, characterized in that: The front end of the PID controller is connected with a subtractor.

3. A method for controlling a solar simulator flash waveform by combining a discharge network with an IGBT according to claim 1, characterized in that: The rear end of the PID controller is connected with an IGBT.

4. A method for controlling a solar simulator flash waveform by combining a discharge network with an IGBT according to claim 2, characterized in that: The inputs of the subtractor are respectively the feedback light intensity and the set light intensity.

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