Hybrid vehicle-mounted inverter system

Abstract

The hybrid vehicle-mounted inverter system is characterized in that a voltage transformation circuit is divided into an input side and an output side, and the input side comprises two input ends, namely a first input end and a second input end; according to the running state of the vehicle, the input ends are selectively selected to be communicated; the output side of the voltage transformation circuit outputs high-voltage direct current; the inverter circuit inputs high-voltage direct current and outputs alternating current from an alternating current output end; the first regulator is connected in front of the first input end and is used for detecting direct current output by the vehicle-mounted battery and regulating the voltage transformation circuit to work according to the direct current; the second regulator is connected in front of the second input end and is used for detecting the direct current output by the power battery and regulating the voltage transformation circuit to work; and the third regulator is connected behind the output end to detect the high-voltage direct current so as to regulate the inverter circuit to work. Through respective open-loop control, the use of special hardware can be reduced, the size is reduced, the cost of parts is also reduced, continuous change is avoided through open-loop control, and the output alternating current is more stable.

Description

Technical Field

[0001] The present invention relates to the field of automotive electronics, and particularly to a hybrid vehicle inverter system. Background Art

[0002] The hybrid vehicle inverter system can convert the direct current (DC) of the vehicle into alternating current (AC). Some electronic devices, such as laptops, chargers, mobile devices, etc., usually require alternating current to work properly. The main function of the hybrid vehicle inverter system is to provide an AC power supply in the vehicle so that drivers and passengers can use these electronic devices.

[0003] The control scheme of the inverter in the prior art adopts closed-loop control, which has high cost and poor stability. Summary of the Invention

[0004] The present invention provides a hybrid vehicle inverter system that uses open-loop control to reduce costs and improve stability.

[0005] The hybrid vehicle inverter system includes: a transformer circuit and an inverter circuit; the transformer circuit is divided into an input side and an output side. The input side has two input terminals, where the first input terminal is connected to the vehicle battery and the second input terminal is connected to the power battery; according to the vehicle operating state, one of the input terminals is selectively connected; the output side of the transformer circuit has at least one output terminal for outputting high-voltage direct current; the inverter circuit inputs the high-voltage direct current and outputs alternating current from the AC output terminal; the vehicle operating state includes at least one of: engine state, internal combustion engine state, throttle opening state; it further includes: a first regulator, connected before the first input terminal, detecting the direct current output by the vehicle battery and adjusting the operation of the transformer circuit accordingly; a second regulator, connected before the second input terminal, detecting the direct current output by the power battery and adjusting the operation of the transformer circuit accordingly; a third regulator, connected after the output terminal, detecting the high-voltage direct current and adjusting the operation of the inverter circuit accordingly.

[0006] Preferably, when the vehicle operating state is: the internal combustion engine starts and the engine is on standby, the first input terminal is connected, and at this time the transformer circuit is in a boost mode; when the vehicle operating state is: the internal combustion engine is on standby and the engine starts, the second input terminal is connected, and at this time the transformer circuit is in a buck mode.

[0007] Preferably, when the vehicle operating state is: the internal combustion engine starts, the engine is on standby, and the throttle opening is less than 40% of the maximum opening, the first input terminal is connected, and at this time the transformer circuit is in a boost mode; when the vehicle operating state is: the internal combustion engine starts, the engine is on standby, and the throttle opening is less than 60% of the maximum opening, the second input terminal is connected, and at this time the transformer circuit is in a buck mode.

[0008] Preferably, it further includes: a first monitor, connected after the output terminal, for monitoring the high-voltage direct current, and cutting off the power input of the first input terminal or the second input terminal when the monitored electrical parameter exceeds a predetermined range; a second monitor, connected after the AC output terminal, for monitoring the alternating current, and cutting off the operation of the inverter circuit when the monitored electrical parameter exceeds a predetermined range.

[0009] Preferably, the first regulator outputs a first PWM signal; the second regulator outputs a second PWM signal; the third regulator outputs a third PWM signal; the first PWM signal and the second PWM signal act on the switching tubes in the voltage transformation circuit; the third PWM signal acts on the switching tubes in the inverter circuit.

[0010] Preferably, the input side and the output side are electrically isolated, and information is transmitted through an optocoupler.

[0011] Preferably, the voltage of the alternating current is 220V and the frequency is 50Hz.

[0012] Preferably, the voltage input at the first input terminal is 14V or 24V; the voltage input at the second input terminal is 800V or 450V.

[0013] In this solution, the primary side and the secondary side are respectively open-loop controlled, which can reduce the use of dedicated hardware, reduce the volume, and also reduce the component cost. The open-loop control avoids the generation of continuous changes and makes the output alternating current more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the hybrid vehicle-mounted inverter system of the present invention. EMBODIMENTS

[0015] The embodiments of the present invention are described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0016] The present invention provides a hybrid vehicle-mounted inverter system, which can convert direct current into alternating current in an open-loop manner. The hybrid vehicle-mounted inverter system can also provide direct current from a power battery or an on-vehicle battery according to the running state of the vehicle, perform corresponding step-up or step-down, and then invert it into alternating current.

[0017] Specifically, the hybrid vehicle-mounted inverter system (referred to as the inverter system for short) has a voltage transformation circuit, an inverter circuit, and a regulator.

[0018] The transformer circuit is divided into an input side and an output side, capable of stepping up or stepping down voltage. The input side and the output side are electrically isolated, and information is transmitted through an optocoupler. The input side has two input terminals. The first input terminal 1 is connected to the vehicle battery, generally a DC input of 12V or 24V. The transformer circuit steps up this voltage to a high-voltage DC of 220V or 100V, and the frequency is generally 50Hz. The specific voltages of the input and output here need to be determined according to the actual situation. For example, if the Chinese standard is 220V / 50Hz, then the voltage is stepped up to 220V here. The second input terminal 2 is connected to the power battery, generally 800V or 450V. Different vehicle models have different settings, but generally they are all higher than 220V. At this time, the transformer circuit steps down this voltage to 220V or 100V. However, at this time, we still call the output high-voltage DC.

[0019] The first input terminal 1 and the second input terminal 2 are selectively connected, and will not be connected and operate simultaneously. It is mainly to judge which input terminal to connect according to the vehicle operating state. The vehicle operating state includes at least one of the engine state, the internal combustion engine state, and the throttle opening state. How to select will be specifically described below.

[0020] On the output side of the transformer circuit, there is at least one output terminal 3 for outputting high-voltage DC. The output terminal can have two, corresponding to the first input terminal 1 and the second input terminal 2 respectively, or only one output terminal can be set. Because the two input terminals are selectively connected, one output terminal 3 can also meet the usage requirements.

[0021] In addition, there is also an inverter circuit, which inputs the high-voltage DC output by the transformer and outputs alternating current from the AC output terminal 4.

[0022] In order to realize the specific control of the transformer circuit and the inverter circuit, a regulator is also included, having at least three - the first regulator 11, the second regulator 21, and the third regulator 31.

[0023] The first regulator 11 is connected before the first input terminal 1, detects the DC output by the vehicle battery, and adjusts the operation of the transformer circuit accordingly; the second regulator 21, connected before the second input terminal 2, detects the DC output by the power battery, and adjusts the operation of the transformer circuit accordingly; the third regulator 31 is connected after the output terminal 3, detects the high-voltage DC, and adjusts the operation of the inverter circuit accordingly.

[0024] The first regulator 11 outputs a first PWM signal; the second regulator 21 outputs a second PWM signal; the third regulator 31 outputs a third PWM signal; The first PWM signal and the second PWM signal act on the switching tubes within the voltage transformation circuit; the third PWM signal acts on the switching tubes within the inverter circuit. The switching tubes mentioned here can be, for example, FETs, IGBTs or other switching elements, depending on the specific circuit structure.

[0025] The first regulator 11 measures the direct current provided by the vehicle-mounted battery and controls the voltage transformation circuit to operate in a step-up manner based on this; the second regulator 21 measures the direct current provided by the power battery and controls the voltage transformation circuit to operate in a step-down manner based on this. The third regulator 31 measures the output high-voltage direct current and controls the operation of the inverter circuit based on this.

[0026] The solution adopted in the present invention is open-loop control. The high-voltage direct current output by the voltage transformation circuit will not be measured by the first regulator 11 and the second regulator 21. That is to say, the regulation of the voltage transformation circuit does not depend on the electrical parameters of the electrical energy output by it, but is based on the input electrical energy. What the third regulator 31 measures is the high-voltage direct current input to the inverter circuit, and the regulation of the inverter circuit also does not depend on the electrical parameters of the alternating current output by it.

[0027] In the traditional solution, closed-loop control is used, which requires dedicated hardware to feedback and adjust the control signal. These dedicated hardware are large in volume and expensive in price. In addition, the closed-loop control may become unstable due to the influence of the load and other possible factors, resulting in the need for the closed-loop system to continuously change to offset the change in the output high-voltage direct current (here taking the primary side as an example, if it is the secondary side, it is to offset the change in the output alternating current).

[0028] In addition to the above open-loop control, it can also include some feedback or sensing for supporting non-control-related operations. For example, a temperature sensor can be placed near the voltage transformation circuit to monitor the operating temperature. If the temperature exceeds the predefined threshold (either higher or lower than the threshold belongs to exceeding), the first regulator 11 or the second regulator 21 may shut down the operation of the voltage transformation circuit.

[0029] It can also include current and voltage monitors, which can monitor the push-pull current and leakage current in addition to the conventional current values and voltage values.

[0030] Preferably, it further includes: two detectors - the first monitor 41 and the second monitor 42.

[0031] The first monitor 41 is connected after the output terminal 3 to monitor the high-voltage direct current. When the monitored electrical parameters exceed the predetermined range, it cuts off the electrical energy input to the first input terminal 1 or the second input terminal 2; the second monitor 42 is connected after the AC output terminal 4 to monitor the alternating current. When the monitored electrical parameters exceed the predetermined range, it cuts off the operation of the inverter circuit.

[0032] The following describes how to determine the selection of the first input terminal 1 and the second input terminal 2 when the vehicle operating state is different.

[0033] When the vehicle operating state is: the internal combustion engine starts and the engine is on standby, the first input terminal 1 is connected, and at this time the voltage conversion circuit is in the boost mode.

[0034] When the vehicle operating state is: the internal combustion engine is on standby and the engine starts, the second input terminal 2 is connected, and at this time the voltage conversion circuit is in the buck mode.

[0035] When the vehicle operating state is: the internal combustion engine starts and the engine is on standby, and the throttle opening is less than 40% of the maximum opening, the first input terminal 1 is connected, and at this time the voltage conversion circuit is in the boost mode.

[0036] When the vehicle operating state is: the internal combustion engine starts and the engine is on standby, and the throttle opening is less than 60% of the maximum opening, the second input terminal 2 is connected, and at this time the voltage conversion circuit is in the buck mode.

[0037] The structure, features and function effects of the present invention have been described in detail based on the embodiments shown in the drawings. The above is only the preferred embodiment of the present invention, but the present invention is not limited to the scope defined by the drawings. Any changes made according to the concept of the present invention, or modified into equivalent embodiments with equivalent changes, still fall within the spirit covered by the specification and the drawings, and should be within the protection scope of the present invention.

Claims

1. A hybrid vehicle inverter system, characterized in that, it includes: a voltage transformation circuit and an inversion circuit; The voltage transformation circuit is divided into an input side and an output side. The input side has two input terminals. The first input terminal (1) is connected to the vehicle-mounted battery, and the second input terminal (2) is connected to the power battery. According to the vehicle running state, one of the input terminals is selectively connected; The output side of the voltage transformation circuit has at least one output terminal (3) to output high-voltage direct current; The inversion circuit inputs the high-voltage direct current and outputs alternating current from the alternating current output terminal (4); The vehicle running state includes at least one of: engine state, internal combustion engine state, and throttle opening state; It further includes: A first regulator (11), connected before the first input terminal (1), detects the direct current output by the vehicle-mounted battery and adjusts the operation of the voltage transformation circuit accordingly; A second regulator (21), connected before the second input terminal (2), detects the direct current output by the power battery and adjusts the operation of the voltage transformation circuit accordingly; A third regulator (31), connected after the output terminal (3), detects the high-voltage direct current and adjusts the operation of the inversion circuit accordingly.

2. The hybrid vehicle inverter system according to claim 1, characterized in that, The vehicle running state is: When the internal combustion engine starts and the engine is on standby, the first input terminal (1) is connected, and at this time the voltage transformation circuit is in the boost mode; The vehicle running state is: When the internal combustion engine is on standby and the engine starts, the second input terminal (2) is connected, and at this time the voltage transformation circuit is in the buck mode.

3. The hybrid vehicle inverter system according to claim 1 or 2, characterized in that, The vehicle running state is: When the internal combustion engine starts, the engine is on standby, and the throttle opening is less than 40% of the maximum opening, the first input terminal (1) is connected, and at this time the voltage transformation circuit is in the boost mode; The vehicle running state is: When the internal combustion engine starts, the engine is on standby, and the throttle opening is less than 60% of the maximum opening, the second input terminal (2) is connected, and at this time the voltage transformation circuit is in the buck mode.

4. The hybrid vehicle inverter system according to claim 1, characterized in that, It further includes: A first monitor (41), connected after the output terminal (3), monitors the high-voltage direct current, and cuts off the power input of the first input terminal (1) or the second input terminal (2) when the monitored electrical parameters exceed a predetermined range; A second monitor (42), connected after the alternating current output terminal (4), monitors the alternating current, and cuts off the operation of the inversion circuit when the monitored electrical parameters exceed a predetermined range.

5. The hybrid vehicle inverter system according to claim 1, characterized in that, The first regulator (11) outputs a first PWM signal; The second regulator (21) outputs a second PWM signal; The third regulator (31) outputs a third PWM signal; The first PWM signal and the second PWM signal act on the switching tubes in the voltage transformation circuit; The third PWM signal acts on the switching tubes in the inversion circuit.

6. The hybrid vehicle inverter system according to claim 1, characterized in that, The input side and the output side are electrically isolated, and information is transmitted through an optocoupler.

7. The hybrid vehicle inverter system according to claim 1, It is characterized in that the voltage of the alternating current is 220V and the frequency is 50Hz.

8. The hybrid vehicle inverter system according to claim 1 It is characterized in that the voltage input at the first input terminal (1) is 14V or 24V; the voltage input at the second input terminal (2) is 800V or 450V.

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