Power supply circuit for auxiliary system of energy storage converter

Abstract

The invention relates to the technical field of power electronic energy storage converters, and provides an energy storage converter auxiliary system power supply circuit, which comprises an alternating current input end serving as the alternating current input of the energy storage converter auxiliary system power supply circuit; the direct-current input end serves as direct-current input of the auxiliary system power supply circuit of the energy storage converter; an industrial frequency transformer; the direct current output side of the rectifying circuit serves as a first direct current load power supply end of the energy storage converter and is connected with the output end of the first DC / DC conversion circuit; the input end of the first DC / DC conversion circuit is connected with the DC input end, and the output end of the first DC / DC conversion circuit is connected with the input end of the second DC / DC conversion circuit and the output end of the rectifying circuit; and the input end of the second DC / DC conversion circuit is connected with the output end of the first DC / DC conversion circuit, and the output end of the second DC / DC conversion circuit serves as a second DC load power supply end of the energy storage converter. The circuit provided by the invention has an uninterruptible power supply function, and the main power supply comes from the AC side of the energy storage converter, so that the burden of the energy storage battery is not increased.

Description

Technical Field

[0001] This invention relates to the field of power electronic energy storage converter technology, and in particular to a power supply circuit for an auxiliary system of an energy storage converter. Background Art

[0002] Energy storage converter systems are complex, with diverse internal electrical loads, including DC and AC loads, each with varying power and voltage characteristics. Furthermore, to meet requirements such as black start, current energy storage converters must possess uninterrupted power supply capabilities.

[0003] Currently, there are two common power supply solutions in the industry: UPS power supply and switching power supply.

[0004] A typical UPS power supply solution includes an AC input terminal, a power frequency transformer, a UPS power supply, an AC / DC switching power supply, and AC and DC load terminals. This solution requires a high-power UPS with a power output equal to or greater than the total power supply of the energy storage converter auxiliary system. The UPS also needs a battery of sufficient capacity, and considering the 20-year design life of the energy storage converter, the batteries require regular maintenance and replacement.

[0005] All of the above increase the system's cost and maintenance workload.

[0006] Furthermore, switching power supply solutions typically include a DC input terminal, a DC / DC switching power supply, a DC / AC switching power supply, and AC and DC load terminals. This solution draws power entirely from the energy storage system's battery side, providing uninterrupted power supply. However, in practical engineering, because the entire system draws power from the battery side, it accelerates battery degradation, reduces charge / discharge capacity, and lowers the accuracy of the energy storage's State of Charge (SOC). Simultaneously, the entire power supply system involves multiple switching power supplies, resulting in low overall conversion efficiency and high cost. Summary of the Invention

[0007] The purpose of this invention is to solve at least one technical problem in the background art and to provide a power supply circuit for an auxiliary system of an energy storage converter.

[0008] To achieve the above objectives, the present invention provides a power supply circuit for an auxiliary system of an energy storage converter, comprising: The AC input terminal is any two of the three phases A, B, and C on the AC side of the energy storage converter, serving as the AC input for the auxiliary system power supply circuit of the energy storage converter. The DC input terminal is the positive and negative terminals of the DC side battery of the energy storage converter, and serves as the DC input for the power supply circuit of the auxiliary system of the energy storage converter. The power frequency transformer has its primary side connected to the AC input terminal, the first secondary side serving as the AC load power supply terminal of the energy storage converter, and the second secondary side connected to the rectifier circuit, serving as the AC input of the rectifier circuit. The rectifier circuit is a diode rectifier bridge, whose DC output side serves as the first DC load power supply terminal of the energy storage converter and is also connected to the output terminal of the first DC / DC converter circuit. The first DC / DC converter circuit has its input terminal connected to the DC input terminal and its output terminal connected to the input terminal of the second DC / DC converter circuit and the output terminal of the rectifier circuit. The second DC / DC converter circuit has its input terminal connected to the output terminal of the first DC / DC converter circuit, and its output terminal serves as the second DC load power supply terminal of the energy storage converter. AC loads, including high-power AC loads in energy storage converters; The first DC load includes the instantaneous high-power, high-voltage load in the energy storage converter; The second DC load includes the control circuit load in the energy storage converter.

[0009] According to one aspect of the invention, the voltage range of the AC input terminal is the AC side output voltage of the energy storage converter.

[0010] According to one aspect of the invention, the AC side output voltage of the energy storage converter is 690V or 800V.

[0011] According to one aspect of the invention, the voltage range of the DC input terminal is the DC side input voltage of the energy storage converter.

[0012] According to one aspect of the present invention, the DC side input voltage of the energy storage converter is 750V~2000V.

[0013] According to one aspect of the invention, the output voltage of the rectifier circuit is DC220V±20%.

[0014] According to one aspect of the invention, the output voltage of the first DC / DC converter circuit is DC200V±20%.

[0015] According to one aspect of the present invention, the output voltage of the second DC / DC converter circuit is 24V, 15V, -15V, or 5V.

[0016] According to the present invention, the output voltage of the rectifier circuit is DC220V±20%, and the output voltage of the first DC / DC converter circuit is set to DC200V±20%. Since the output voltage of the rectifier circuit is greater than the set output voltage of the first DC / DC converter circuit, the first DC / DC converter circuit is in a pulse-blocking mode with no power output, and the inputs of the first DC load and the second DC / DC converter circuit are both provided by the rectifier circuit.

[0017] When the AC side is de-energized, the rectifier circuit output voltage is 0. At this time, the first DC / DC converter circuit outputs voltage normally, and the input of the first DC load and the second DC / DC converter circuit is provided by the first DC / DC converter circuit.

[0018] When the AC side resumes power supply, the rectifier circuit continues to supply power to the first DC load and the second DC / DC converter circuit, and the first DC / DC converter circuit enters the pulse blocking mode.

[0019] According to the above-described solution of the present invention, compared with traditional UPS power supply and switching power supply methods, the circuit of the present invention has uninterrupted power supply function, and at the same time, the main power source is the AC side of the energy storage converter, which does not increase the burden on the energy storage battery. Furthermore, the circuit of the present invention has the characteristics of low cost, high efficiency, high reliability, and simple operation and maintenance. Attached Figure Description

[0020] Figure 1 A schematic diagram illustrating the power supply circuit of the energy storage converter auxiliary system according to Embodiment 1 of the present invention; Figure 2 The diagram schematically illustrates the rectifier circuit in the power supply circuit of the energy storage converter auxiliary system according to Embodiment 1 of the present invention. Detailed Implementation

[0021] The invention will now be discussed with reference to exemplary embodiments. It should be understood that the described embodiments are merely intended to enable those skilled in the art to better understand and thus implement the invention, and are not intended to imply any limitation on the scope of the invention.

[0022] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment".

[0023] To achieve the above objectives, the present invention provides a power supply circuit for an auxiliary system of an energy storage converter, comprising: The AC input terminal is any two of the three phases A, B, and C on the AC side of the energy storage converter, serving as the AC input for the auxiliary system power supply circuit of the energy storage converter. The DC input terminal is the positive and negative terminals of the DC side battery of the energy storage converter, and serves as the DC input for the power supply circuit of the auxiliary system of the energy storage converter. The power frequency transformer has its primary side connected to the AC input terminal, the first secondary side serving as the AC load power supply terminal of the energy storage converter, and the second secondary side connected to the rectifier circuit, serving as the AC input of the rectifier circuit. The rectifier circuit is a diode rectifier bridge, whose DC output side serves as the first DC load power supply terminal of the energy storage converter and is also connected to the output terminal of the first DC / DC converter circuit. The first DC / DC converter circuit has its input terminal connected to the DC input terminal and its output terminal connected to the input terminal of the second DC / DC converter circuit and the output terminal of the rectifier circuit. The second DC / DC converter circuit has its input terminal connected to the output terminal of the first DC / DC converter circuit, and its output terminal serves as the second DC load power supply terminal of the energy storage converter. AC loads, including high-power AC loads in energy storage converters; The first DC load includes the instantaneous high-power, high-voltage load in the energy storage converter; The second DC load includes the control circuit load in the energy storage converter.

[0024] Furthermore, according to one embodiment of the present invention, the voltage range of the AC input terminal is the AC side output voltage of the energy storage converter.

[0025] Furthermore, according to one embodiment of the present invention, the AC side output voltage of the energy storage converter is 690V or 800V.

[0026] Furthermore, according to one embodiment of the present invention, the voltage range of the DC input terminal is the DC side input voltage of the energy storage converter.

[0027] Furthermore, according to one embodiment of the present invention, the DC side input voltage of the energy storage converter is 750V~2000V.

[0028] Furthermore, according to one embodiment of the present invention, the output voltage of the rectifier circuit is DC220V±20%.

[0029] Furthermore, according to one embodiment of the present invention, the output voltage of the first DC / DC converter circuit is DC200V±20%.

[0030] Furthermore, according to one embodiment of the present invention, the output voltage of the second DC / DC converter circuit is 24V, 15V, -15V, or 5V.

[0031] According to the above-described scheme of the present invention, the output voltage of the rectifier circuit is DC220V±20%, and the output voltage of the first DC / DC converter circuit is set to DC200V±20%. Since the output voltage of the rectifier circuit is greater than the set output voltage of the first DC / DC converter circuit, the first DC / DC converter circuit is in pulse-blocking mode and has no power output. The inputs of the first DC load and the second DC / DC converter circuit are both provided by the rectifier circuit.

[0032] When the AC side is de-energized, the rectifier circuit output voltage is 0. At this time, the first DC / DC converter circuit outputs voltage normally, and the input of the first DC load and the second DC / DC converter circuit is provided by the first DC / DC converter circuit.

[0033] When the AC side resumes power supply, the rectifier circuit continues to supply power to the first DC load and the second DC / DC converter circuit, and the first DC / DC converter circuit enters the pulse blocking mode.

[0034] According to the above-described solution of the present invention, compared with traditional UPS power supply and switching power supply methods, the circuit of the present invention has uninterrupted power supply function, and at the same time, the main power source is the AC side of the energy storage converter, which does not increase the burden on the energy storage battery. Furthermore, the circuit of the present invention has the characteristics of low cost, high efficiency, high reliability, and simple operation and maintenance.

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely one preferred embodiment of the invention and are only used to explain the invention. They do not limit the scope of protection of the invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] Example 1 Figure 1 A schematic diagram illustrating the power supply circuit of the energy storage converter auxiliary system according to Embodiment 1 of the present invention; Figure 2 This schematic diagram illustrates the rectifier circuit in the power supply circuit of the energy storage converter auxiliary system according to Embodiment 1 of the present invention. Figure 1 and Figure 2 As shown, in this embodiment, the power supply circuit for the energy storage converter auxiliary system includes: AC input terminal 1 is the AC side A and B phase terminals of the energy storage converter, which serves as the AC input for the auxiliary system power supply circuit of the energy storage converter. The rated voltage of the AC input terminal is AC690V. DC input terminal 5 is the positive and negative terminals of the DC side battery of the energy storage converter. It serves as the DC input for the auxiliary system power supply circuit of the energy storage converter. The voltage range of the DC input terminal is DC1000V~DC1500V. The power frequency transformer 2 has an AC input terminal 1 connected to the primary side. The first secondary side has a rated output voltage of AC230V, which is directly output and serves as the power supply terminal for the AC load 9 of the energy storage converter. The second secondary side has a rated output voltage of AC157V, which is connected to the rectifier circuit 3 and serves as the AC input of the rectifier circuit 3. Rectifier circuit 3 is a diode rectifier bridge. Its DC output side serves as the power supply terminal for the first DC load 4 of the energy storage converter, and is also connected to the output terminal of the first DC / DC converter circuit 6. The circuit diagram of the rectifier circuit is shown below. Figure 2 As shown; The first DC / DC converter circuit 6 has its input terminal connected to the DC input terminal 5 and its output voltage set to DC 200V. It is connected to the input terminal of the second DC / DC converter circuit 7 and the output terminal of the rectifier circuit 3. The second DC / DC converter circuit 7 has its input terminal connected to the output terminal of the first DC / DC converter circuit 6, and its output voltage is DC24V, serving as the power supply terminal for the second DC load 8 of the energy storage converter. AC load 9, AC load includes high-power AC loads in the energy storage converter, such as fans, heaters, and air conditioners; The first DC load 4 includes the instantaneous high-power high-voltage load in the energy storage converter, the drive motor of the frame disconnect switch and the frame circuit breaker. The second DC load 8 includes the control circuit load in the energy storage converter, such as the control circuit, sampling circuit, and drive circuit.

[0037] In this embodiment, since the output voltage of the rectifier circuit 3 is greater than the set output voltage of the first DC / DC converter circuit 6, the first DC / DC converter circuit 6 is in pulse-blocking mode and has no power output. The input of the first DC load 4 and the second DC / DC converter circuit 7 is provided by the rectifier circuit 3.

[0038] When the AC side is de-energized, the output voltage of the rectifier circuit 3 is 0. At this time, the first DC / DC converter circuit 6 outputs a normal voltage. The input of the first DC load 4 and the second DC / DC converter circuit 7 is provided by the first DC / DC converter circuit 6.

[0039] Once power is restored to the AC side, the rectifier circuit 3 will once again provide energy to the first DC load 4 and the second DC / DC converter circuit 7, while the first DC / DC converter circuit 6 will switch to the pulse-blocking mode.

[0040] According to the above scheme of this embodiment, compared with the traditional UPS power supply and switching power supply methods, the circuit of this embodiment has the function of uninterrupted power supply, and at the same time, the main power source is the AC side of the energy storage converter, which does not increase the burden on the energy storage battery. Furthermore, the circuit of this embodiment has the characteristics of low cost, high efficiency, high reliability and simple operation and maintenance.

[0041] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

[0042] It should be understood that the sequence number of each step in the invention and its embodiments does not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A power supply circuit for an auxiliary system of an energy storage converter, characterized in that, include: The AC input terminal is any two of the three phases A, B, and C on the AC side of the energy storage converter, serving as the AC input for the auxiliary system power supply circuit of the energy storage converter. The DC input terminal is the positive and negative terminals of the DC side battery of the energy storage converter, and serves as the DC input for the power supply circuit of the auxiliary system of the energy storage converter. The power frequency transformer has its primary side connected to the AC input terminal, the first secondary side serving as the AC load power supply terminal of the energy storage converter, and the second secondary side connected to the rectifier circuit, serving as the AC input of the rectifier circuit. The rectifier circuit is a diode rectifier bridge, whose DC output side serves as the first DC load power supply terminal of the energy storage converter and is also connected to the output terminal of the first DC / DC converter circuit. The first DC / DC converter circuit has its input terminal connected to the DC input terminal and its output terminal connected to the input terminal of the second DC / DC converter circuit and the output terminal of the rectifier circuit. The second DC / DC converter circuit has its input terminal connected to the output terminal of the first DC / DC converter circuit, and its output terminal serves as the second DC load power supply terminal of the energy storage converter. AC loads, including high-power AC loads in energy storage converters; The first DC load includes the instantaneous high-power, high-voltage load in the energy storage converter; The second DC load includes the control circuit load in the energy storage converter.

2. The power supply circuit for the auxiliary system of the energy storage converter according to claim 1, characterized in that, The voltage range of the AC input terminal is the AC output voltage of the energy storage converter.

3. The power supply circuit for the auxiliary system of the energy storage converter according to claim 2, characterized in that, The AC output voltage of the energy storage converter is 690V or 800V.

4. The power supply circuit for the auxiliary system of the energy storage converter according to claim 1, characterized in that, The voltage range of the DC input terminal is the DC side input voltage of the energy storage converter.

5. The power supply circuit for the auxiliary system of the energy storage converter according to claim 4, characterized in that, The DC input voltage of the energy storage converter is 750V~2000V.

6. The power supply circuit for the auxiliary system of the energy storage converter according to claim 1, characterized in that, The output voltage of the rectifier circuit is DC220V±20%.

7. The power supply circuit for the auxiliary system of the energy storage converter according to claim 1, characterized in that, The output voltage of the first DC / DC converter circuit is DC200V±20%.

8. The power supply circuit for the auxiliary system of the energy storage converter according to any one of claims 1-7, characterized in that, The output voltages of the second DC / DC converter circuit are 24V, 15V, -15V, and 5V.

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