A high-frequency light-weight variable frequency power supply system

Abstract

The utility model discloses a kind of high-frequency light-weight variable frequency power supply systems, comprising: soft-starting circuit, isolation boost circuit, inverter circuit, drive circuit, sampling circuit, auxiliary power supply, main control circuit, communication unit, PC end;Among them, the soft-starting circuit, comprising: first terminal, second terminal, control switch, thermistor, first capacitor, second capacitor, common mode inductance, rectifier bridge, first bus capacitor, PCB terminal, power contactor;First terminal is connected to power contactor by connecting first capacitor, and the power contactor can be connected to PCB terminal by connecting thermistor selectively;Second terminal can be connected to PCB terminal by connecting control switch selectively.The utility model reduces volume and weight to reasonable level, can be done desktop case or small cabinet, adapt to customer needs, convenient transportation and operation.

Description

Technical Field

[0001] This utility model relates to the field of frequency converter technology, specifically a high-frequency and lightweight frequency converter system. Background Technology

[0002] Variable frequency power supplies are becoming increasingly widely used, and they are indispensable in various industrial production and product testing applications. However, the image of a variable frequency power supply often evokes images of a bulky, cabinet-style unit with wheels, making it difficult to move. Indeed, conventional high-power variable frequency power supplies typically incorporate high-power power frequency transformers, which are quite large and heavy, causing numerous inconveniences.

[0003] Currently, most customers in the market require AC voltages of 0-300V. Using the aforementioned variable frequency power supplies presents significant problems due to their large size and weight. For example, a patent application (CN202510877476.1) for a dedicated intelligent testing device and method for power UPS mentions: a multi-source power supply system is constructed by integrating a three-phase programmable frequency converter, a single-phase programmable frequency converter, and a DC programmable frequency converter. Combined with a resistive and rectifier dual-mode electronic load, an embedded control system achieves millisecond-level synchronous switching between voltage levels and load states, forming a closed-loop testing capability for multi-dimensional performance of the power UPS. The variable frequency power supply in this patent is not only difficult to transport but also inconvenient to use.

[0004] Existing technologies can no longer meet people's current needs, and based on the current situation, there is an urgent need to improve existing technologies. Utility Model Content

[0005] The purpose of this invention is to provide a high-frequency and lightweight variable frequency power supply system to solve the problems mentioned in the background art.

[0006] This utility model provides the following technical solution: a high-frequency and lightweight inverter power supply system, comprising: a soft-start circuit, an isolation boost circuit, an inverter circuit, a drive circuit, a sampling circuit, an auxiliary power supply, a main control circuit, a communication unit, and a PC terminal;

[0007] The soft-start circuit includes: a first terminal block, a second terminal block, a control switch, a thermistor, a first capacitor, a second capacitor, a common-mode inductor, a rectifier bridge, a first bus capacitor, a PCB terminal block, and a power contactor. The first and second terminal blocks serve as the input terminals of the soft-start circuit. The first terminal block is connected to the power contactor via the first capacitor, and the power contactor can be selectively connected to the PCB terminal block via the thermistor. The second terminal block can be selectively connected to the PCB terminal block via the control switch. The output terminal of the second terminal block is connected to the power contactor. The power supply terminal of the power contactor is connected to an auxiliary power supply, and the power supply terminal of the PCB terminal block is also connected to the auxiliary power supply. The output terminal of the PCB terminal block is connected to the rectifier bridge via the common-mode inductor. The common-mode inductor has a first capacitor and a second capacitor at its two ends, respectively. The output terminal of the rectifier bridge is connected to the first bus capacitor. The first capacitor, the second capacitor, the common-mode inductor, and the rectifier bridge constitute a rectifier and filter circuit.

[0008] The isolation boost circuit includes: a first IGBT module, a second IGBT module, a high-frequency transformer, a first rectifier module, a second rectifier module, a second bus capacitor, and a third bus capacitor; wherein, the first IGBT module and the second IGBT module are coupled to the drive circuit, and the first IGBT module and the second IGBT module are connected in parallel to the positive and negative terminals of the first bus capacitor, one input terminal of the high-frequency transformer is connected to the first IGBT module, and the other input terminal of the high-frequency transformer is connected to the second IGBT module, one output terminal of the high-frequency transformer is connected to the first rectifier module, and the other output terminal of the high-frequency transformer is connected to the second rectifier module, and the other ends of the first rectifier module and the second rectifier module are respectively connected to the second bus capacitor and the third bus capacitor, and the second bus capacitor is connected in series with the third bus capacitor;

[0009] The inverter circuit includes: a third IGBT module, a fourth IGBT module, and a filter module; the third IGBT module and the fourth IGBT module are coupled to a drive circuit; and the second bus capacitor and the third bus capacitor are connected in parallel to the third IGBT module and the fourth IGBT module, and the third IGBT module is connected to one input terminal of the filter module, and the fourth IGBT module is connected to the other input terminal of the filter module, and the output terminal of the filter module is connected to a sampling circuit; wherein, the filter module includes: a first inductor, a second inductor, and a third capacitor, and the first inductor is coupled to the third IGBT module, the second inductor is coupled to the fourth IGBT module, and the first inductor and the second inductor are coupled to the third capacitor;

[0010] The sampling circuit is respectively coupled to sampling points A and B at the output of the inverter circuit, and is used to detect whether the AC voltage output by the inverter circuit is the voltage required by the customer.

[0011] The auxiliary power supply, drive circuit, and sampling circuit are all connected to the main control circuit, and the main control circuit is connected to the PC through a communication unit. The PC controls the main control circuit to generate control signals through the communication unit.

[0012] This utility model has the following beneficial effects:

[0013] (1) The design without power frequency transformer has a wider range of output frequency, which can easily meet the current market demand for output of 0-300V AC voltage. Moreover, the isolation boost circuit and inverter circuit are driven and controlled by the control drive circuit to output the required AC voltage value. The output voltage is sampled by the sampling circuit to achieve precise control of the output AC voltage.

[0014] (2) By reducing the volume and weight to a reasonable level, desktop chassis or small cabinets can be made to meet customer needs and facilitate transportation and operation. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall circuit structure of this utility model. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the present utility model without creative effort are within the protection scope of the present utility model.

[0017] refer to Figure 1 This utility model provides the following technical solution: a high-frequency and lightweight variable frequency power supply system, including: a soft-start circuit, an isolation boost circuit, an inverter circuit, a drive circuit, a sampling circuit, an auxiliary power supply, a main control circuit, a communication unit, and a PC terminal;

[0018] The soft-start circuit includes: first terminal P1, second terminal P2, control switch SW, thermistor PTC, first capacitor CX1, second capacitor CX2, common mode inductor LC1, rectifier bridge B1, first bus capacitor E1, PCB terminal CN1, and power contactor RLY1.

[0019] The first terminal P1 and the second terminal P2 serve as the input terminals of the soft-start circuit. The first terminal P1 is connected to the power contactor RLY1 via a first capacitor CX1, and the power contactor RLY1 can be selectively connected to the PCB terminal CN1 via a thermistor PTC. The second terminal P2 can be selectively connected to the PCB terminal CN1 via a control switch SW. The output terminal of the second terminal P2 is connected to the power contactor RLY1, and the power supply terminal of the power contactor RLY1 is connected to the auxiliary power supply. The power supply terminal of the PCB terminal CN1 is also connected to the auxiliary power supply. The output terminal of the PCB terminal CN1 is connected to the rectifier bridge B1 via a common-mode inductor LC1. The two ends of the common-mode inductor LC1 are respectively provided with a first capacitor CX1 and a second capacitor CX2. The output terminal of the rectifier bridge B1 is connected to the first bus capacitor E1. The first capacitor CX1, the second capacitor CX2, the common-mode inductor LC1, and the rectifier bridge B1 constitute a rectification and filtering circuit.

[0020] In this embodiment, when the control switch is closed, the PCB terminal CN1, auxiliary power supply, power contactor RLY1, and control switch SW form a closed main circuit. The auxiliary power supply supplies power to the PCB terminal CN1 and the power contactor RLY1. When the external 220V AC mains power is connected to the soft-start circuit through the first terminal P1 and the second terminal P2, the auxiliary power supply is powered on after the control switch SW is closed. At the same time, the main circuit charges the bus capacitor E1 through the thermistor PTC and the rectifier and filter circuit. After the auxiliary power supply is normal, the voltage of the bus capacitor E1 is also charged to a certain voltage. At this time, the power contactor RLY1 is energized, completing the soft-start process. Since the 220V AC mains power is AC voltage, after processing by the rectifier and filter circuit, the soft-start circuit outputs 310V. DC voltage (DC310V);

[0021] The isolation boost circuit includes: a first IGBT module, a second IGBT module, a high-frequency transformer T2, a first rectifier module, a second rectifier module, a second bus capacitor E2, and a third bus capacitor E3; wherein,

[0022] The first IGBT module and the second IGBT module are coupled to the driving circuit, and the first IGBT module and the second IGBT module are connected in parallel to the positive and negative terminals of the first bus capacitor E1. One input terminal of the high-frequency transformer T2 is connected to the first IGBT module, and the other input terminal of the high-frequency transformer T2 is connected to the second IGBT module. One output terminal of the high-frequency transformer T2 is connected to the first rectifier module, and the other output terminal of the high-frequency transformer T2 is connected to the second rectifier module. The other ends of the first rectifier module and the second rectifier module are respectively connected to the second bus capacitor E2 and the third bus capacitor E3, and the second bus capacitor E2 is connected in series with the third bus capacitor E3.

[0023] In this embodiment, the isolation boost circuit is used to achieve isolation and boosting of the input power supply. Taking the current market demand of 0-300V AC voltage as an example, it is necessary to first input PWM waves to the first IGBT module and the second IGBT module through the drive circuit. By setting the PWM duty cycle, the DC310V DC voltage is boosted by the high-frequency transformer T2 and rectified into DC480V by the first rectifier module and the second rectifier module, and stored in the second bus capacitor E2 and the third bus capacitor E3.

[0024] The inverter circuit includes: a third IGBT module, a fourth IGBT module, and a filter module;

[0025] The third IGBT module and the fourth IGBT module are coupled to the driving circuit; the second bus capacitor E2 and the third bus capacitor E3 are connected in parallel to the third IGBT module and the fourth IGBT module; the third IGBT module is connected to one input terminal of the filter module; the fourth IGBT module is connected to the other input terminal of the filter module; and the output terminal of the filter module is connected to the sampling circuit; wherein, the filter module includes: a first inductor L1, a second inductor L2, and a third capacitor C1; the first inductor L1 is coupled to the third IGBT module; the second inductor L2 is coupled to the fourth IGBT module; and the first inductor L1 and the second inductor L2 are coupled to the third capacitor C1.

[0026] In this embodiment, the inverter circuit is used to convert DC480V DC voltage into AC voltage of 0-300V. First, an SPWM wave is input to the third IGBT module and the fourth IGBT module through the drive circuit. After the DC480V DC voltage is inverted by the full-bridge inverter bridge composed of the third IGBT module and the fourth IGBT module, it is converted into an SPWM wave (AC voltage signal). Then, after being processed by the LC low-pass filter composed of the first inductor L1, the second inductor L2, and the third capacitor CI, it is converted into a standard sine wave.

[0027] The drive circuit is used to drive the amplitude of the SPWM wave output, that is, to output a 0-300V AC voltage according to the customer's requirements. A larger drive capability results in a larger sine wave amplitude, which in turn results in a larger AC voltage output after processing by the filter module. Conversely, a smaller drive capability results in a smaller sine wave amplitude, which in turn results in a smaller AC voltage output. Therefore, the output AC voltage of 0-300V can be achieved by adjusting the drive capability of the drive circuit.

[0028] The sampling circuit is coupled to sampling points A and B at the output of the inverter circuit to detect whether the AC voltage output by the inverter circuit is the voltage required by the customer. After processing by the inverter circuit, the output AC voltage is 0-300V. For example, if the output is AC280V, the sampling circuit detects whether the sampling point is AC280V, making the AC voltage output by the entire circuit more accurate.

[0029] The auxiliary power supply, drive circuit, and sampling circuit are all connected to the main control circuit, and the main control circuit is connected to the PC through a communication unit. The PC controls the main control circuit to generate control signals through the communication unit. On the one hand, it controls the drive circuit to drive and control the isolation boost circuit and inverter circuit. On the other hand, it samples the output voltage of the sampling circuit to achieve precise control of the output.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-frequency, lightweight variable frequency power supply system, characterized in that, include: The soft-start circuit includes: a first terminal block, a second terminal block, a control switch, a thermistor, a first capacitor, a second capacitor, a common-mode inductor, a rectifier bridge, a first bus capacitor, PCB terminals, and a power contactor. The first and second terminals serve as input terminals of the soft-start circuit; wherein, the first terminal is connected to a power contactor via a first capacitor, and the power contactor can be optionally connected to the PCB terminal via a thermistor; the second terminal can be optionally connected to the PCB terminal via a control switch; and the output terminal of the second terminal is connected to the power contactor. The power contactor's power supply terminal is connected to the auxiliary power supply, and the PCB terminal's power supply terminal is also connected to the auxiliary power supply. The output terminal of the PCB terminal is connected to the rectifier bridge through a common-mode inductor. The two ends of the common-mode inductor are respectively provided with a first capacitor and a second capacitor. The output terminal of the rectifier bridge is connected to a first bus capacitor. The first capacitor, the second capacitor, the common-mode inductor, and the rectifier bridge constitute a rectifier and filter circuit. The isolation boost circuit includes: a first IGBT module, a second IGBT module, a high-frequency transformer, a first rectifier module, a second rectifier module, a second bus capacitor, and a third bus capacitor; wherein, The first IGBT module and the second IGBT module are coupled to the driving circuit, and the first IGBT module and the second IGBT module are connected in parallel to the positive and negative terminals of the first bus capacitor. One input terminal of the high-frequency transformer is connected to the first IGBT module, and the other input terminal of the high-frequency transformer is connected to the second IGBT module. One output terminal of the high-frequency transformer is connected to the first rectifier module, and the other output terminal of the high-frequency transformer is connected to the second rectifier module. The other ends of the first rectifier module and the second rectifier module are respectively connected to the second bus capacitor and the third bus capacitor, and the second bus capacitor is connected in series with the third bus capacitor. The inverter circuit includes: a third IGBT module, a fourth IGBT module, and a filter module; The third and fourth IGBT modules are coupled to the driving circuit; the second bus capacitor and the third bus capacitor are connected in parallel to the third and fourth IGBT modules; the third IGBT module is connected to one input terminal of the filter module; the fourth IGBT module is connected to the other input terminal of the filter module; and the output terminal of the filter module is connected to the sampling circuit. The filter module includes a first inductor, a second inductor, and a third capacitor; the first inductor is coupled to the third IGBT module; the second inductor is coupled to the fourth IGBT module; and the first and second inductors are coupled to the third capacitor. The sampling circuit is coupled to sampling points A and B at the output of the inverter circuit to detect whether the AC voltage output by the inverter circuit is the voltage required by the customer. The auxiliary power supply, drive circuit, and sampling circuit are all connected to the main control circuit, and the main control circuit is connected to the PC through a communication unit. The PC controls the main control circuit to generate control signals through the communication unit.

2. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: The PCB terminals, auxiliary power supply, power contactor, and control switch form a closed main circuit; and... The main circuit charges the bus capacitor through a thermistor and rectifier filter circuit, and the power contactor engages to complete the soft start process.

3. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: When 220V AC voltage is input to the first and second terminals, the soft-start circuit outputs a maximum of 310V DC voltage.

4. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: The driving circuit inputs PWM waves to the first IGBT module and the second IGBT module. By setting the PWM duty cycle, the 310V DC voltage is boosted by the high-frequency transformer and rectified into 480V DC voltage by the first rectifier module and the second rectifier module, and stored on the second bus capacitor and the third bus capacitor.

5. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: The driving circuit inputs an SPWM wave to the third IGBT module and the fourth IGBT module. The 480V DC voltage is converted into an SPWM wave after being inverted by the full-bridge inverter bridge composed of the third IGBT module and the fourth IGBT module. After being processed by the low-pass filter composed of the first inductor, the second inductor and the third capacitor, it is converted into a standard sine wave.

6. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: The driving circuit is used to drive the amplitude of the SPWM wave output and adjust the magnitude of the output AC voltage.

7. The high-frequency lightweight inverter power supply system according to claim 1, characterized in that: Therefore, by adjusting the driving capability of the drive circuit, an AC voltage output of 0-300V can be achieved.

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