Converter and power supply equipment

Abstract

The utility model discloses a converter and power supply equipment, which are applied to the technical field of power electronic converters, a power supply switching circuit is added on the basis of an original converter, an auxiliary power supply is correspondingly improved, and the power supply switching circuit is respectively connected with a bus input end of the converter and a bus support capacitor. When the converter is shut down, the disconnecting switch is disconnected, the controller controls the electric energy input of the power supply switching circuit to be switched to the second input end, the auxiliary power supply takes electricity from the bus support capacitor through the power supply switching circuit, and the load is controlled to continuously operate to consume energy in the support capacitor. According to the utility model, on the basis of only adding the power supply switching circuit and improving the auxiliary power supply, a power supply loop of a load in the original equipment of the converter is converted into a circuit for discharging the bus support capacitor, so that the converter discharges the support capacitor while controlling the cost and not adding extra devices.

Description

Technical Field

[0001] This utility model relates to the field of power electronic converter technology, and in particular to a converter and power supply equipment. Background Technology

[0002] Converters typically have bus support capacitors to provide a stable input voltage for subsequent conversion stages. After shutdown, it is necessary to promptly discharge the charge stored in the bus support capacitors to ensure the safety of maintenance personnel. A common method is to add a parallel resistor across the bus support capacitor to discharge the voltage to a safe level. However, this added parallel resistor increases losses during normal converter operation, and the resistor will also remain under high temperature for extended periods.

[0003] In existing technologies, to prevent the parallel resistor from overheating during operation, a switch is usually connected in series next to the resistor, and the parallel resistor is activated to discharge voltage when the system is shut down. However, adding a high-voltage switch for active discharge and a high-power parallel discharge resistor undoubtedly increases the cost of the equipment. Furthermore, the large size of the high-power resistor also increases the size of the converter. This increased size further increases the cost of the cabinet and the floor space required.

[0004] Therefore, how to discharge the support capacitor while controlling costs and without adding additional components is a technical problem that urgently needs to be solved by those in the field. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a converter and power supply equipment that solves the problem of discharging the supporting capacitor while controlling costs and without adding additional components. The specific solution is as follows:

[0006] In a first aspect, this application provides a converter, including a disconnecting switch and a bus support capacitor, and further including: a power supply switching circuit and an auxiliary power supply;

[0007] The disconnecting switch is located between the bus input terminal of the converter and the bus support capacitor;

[0008] The first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter to form a first circuit; the second input terminal of the power supply switching circuit is connected to the bus support capacitor to form a second circuit; the output terminal of the power supply switching circuit is connected to the input terminal of the load through the auxiliary power supply, and is used to disconnect the first circuit and connect the second circuit when the disconnecting switch is opened.

[0009] Optionally, the power supply switching circuit includes a single-pole double-throw relay;

[0010] The first contact of the relay is connected to the bus input terminal of the converter as the first input terminal of the power supply switching circuit.

[0011] The second contact of the relay is connected to the bus support capacitor as the second input terminal of the power supply switching circuit.

[0012] The common contact of the relay serves as the output terminal of the power supply switching circuit and is connected to the input terminal of the load via the auxiliary power supply.

[0013] Optionally, the power supply switching circuit includes: a first controllable switch and a second controllable switch;

[0014] The first terminal of the first controllable switch is connected to the bus input terminal of the converter as the first input terminal of the power supply switching circuit.

[0015] The first terminal of the second controllable switch is connected to the bus support capacitor as the second input terminal of the power supply switching circuit.

[0016] The second terminal of the first controllable switch is connected to the second terminal of the second controllable switch, and their common terminal is connected to the input terminal of the load as the output terminal of the power supply switching circuit.

[0017] Optionally, the auxiliary power supply includes: a first auxiliary power supply and a second auxiliary power supply;

[0018] The first terminal of the first auxiliary power supply is connected to the output terminal of the power supply switching circuit, and the second terminal of the first auxiliary power supply is connected to the input terminal of the load, so as to supply power to the load using the bus input terminal of the converter;

[0019] The first end of the second auxiliary power supply is connected to the output end of the power supply switching circuit, and the second end of the second auxiliary power supply is connected to the input end of the load, so as to use the electrical energy of the bus support capacitor to supply power to the load.

[0020] Optionally, the auxiliary power supply is an AC / DC hybrid power supply.

[0021] Optionally, it may also include: a voltage sampling circuit;

[0022] The input terminal of the voltage sampling circuit is connected to the busbar support capacitor and is used to detect the voltage of the busbar support capacitor.

[0023] Optionally, it may also include: a controller;

[0024] The input terminal of the controller is connected to the bus support capacitor through the voltage sampling circuit, and is used to obtain the voltage of the bus support capacitor detected by the voltage sampling circuit;

[0025] The output terminal of the controller is connected to the control input terminal of the power supply switching circuit, and is used to send control signals of the switching circuit based on the voltage of the bus support capacitor and the open / closed state of the disconnecting switch.

[0026] Optional features also include: a discharge circuit;

[0027] The discharge circuit is connected in parallel across the two ends of the busbar support capacitor, and the input terminal of the discharge circuit is connected to the controller for turning on or off based on the controller's command.

[0028] Optionally, the discharge circuit includes: a discharge resistor and a third controllable switch;

[0029] The bleeder resistor and the third controllable switch are connected in series as a whole and then connected in parallel across the two ends of the busbar support capacitor. The control terminal of the third controllable switch is connected to the controller as the input terminal of the bleeder circuit.

[0030] Secondly, this application provides a power supply device, including the aforementioned converter.

[0031] Therefore, this invention achieves bus support capacitor discharge by adding a power supply switching circuit and correspondingly improving the auxiliary power supply to the existing converter. The power supply switching circuit is connected to the bus input terminal and the bus support capacitor of the converter. When the converter is running normally, the auxiliary power supply obtains power from the bus input terminal of the converter through the first input terminal of the power supply switching circuit, ensuring normal power supply to the load on the converter. When the converter is shut down, the isolating switch is opened, and the controller controls the power input of the power supply switching circuit to the second input terminal. The auxiliary power supply then draws power from the bus support capacitor through the power supply switching circuit, controlling the load to continue running to consume the energy in the support capacitor. This invention, by only adding a power supply switching circuit and improving the auxiliary power supply, utilizes the power supply circuit of the load in the original equipment of the converter to convert it into a circuit for discharging the bus support capacitor, solving the problem of discharging the support capacitor in the converter while controlling costs and without adding additional components. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 A single-line diagram of the internal structure of a converter provided in this application embodiment;

[0034] Figure 2A power supply switching circuit diagram provided in an embodiment of this application;

[0035] Figure 3 A power supply switching circuit diagram provided in an embodiment of this application;

[0036] Figure 4 A single-line diagram showing the internal structure of a converter provided in this application embodiment. Detailed Implementation

[0037] 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. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0038] The core of this application is to provide a converter.

[0039] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In a converter, the bus support capacitor provides a stable input voltage for subsequent conversion stages. After shutdown, the stored charge in the bus support capacitor needs to be discharged promptly to ensure the safety of maintenance personnel. Current technology typically involves adding a parallel resistor across the bus support capacitor to discharge its voltage to a safe level. However, this added parallel resistor increases losses during normal converter operation, and the resistor also remains at a high temperature for extended periods. Therefore, to prevent the parallel resistor from overheating during operation, a switch is usually connected in series across the resistor, and the parallel resistor is activated to discharge voltage during shutdown. However, adding an active discharge high-voltage switch and a high-power parallel discharge resistor undoubtedly increases equipment costs. Furthermore, the large size of the high-power resistor also increases the size of the converter. This increased size further increases cabinet and floor space costs.

[0041] Therefore, how to discharge the support capacitor while controlling costs and without adding additional components is a technical problem that urgently needs to be solved by those in the field.

[0042] See Figure 1As shown, to address the aforementioned issue of discharging the supporting capacitor while controlling costs and without adding additional components, this application discloses a converter, including a disconnect switch and a bus support capacitor, and further including: a power supply switching circuit and an auxiliary power supply; the disconnect switch is disposed between the bus input terminal of the converter and the bus support capacitor; the first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter to form a first circuit; the second input terminal of the power supply switching circuit is connected to the bus support capacitor to form a second circuit; the output terminal of the power supply switching circuit is connected to the input terminal of the load through the auxiliary power supply, for disconnecting the first circuit and connecting the second circuit when the disconnect switch is open.

[0043] In this embodiment, the converter's bus input terminal is connected to an external energy storage battery, and then connected to the converter's bus support capacitor after being isolated by an isolating switch. During normal operation, the isolating switch is closed, drawing power from the external energy storage battery. When the converter stops, the isolating switch opens, and the converter bus carries high voltage due to the stored charge in the bus support capacitor, posing a personal danger to maintenance personnel entering the cabinet for inspection. Therefore, the voltage in the bus support capacitor should be discharged promptly to ensure personnel safety. In this embodiment, the auxiliary power supply and load are essential components for the converter's operation. The power supply switching circuit is a new addition to switch the auxiliary power supply source. During normal operation, the power supply switching circuit allows the auxiliary power supply to draw power from the converter's bus input terminal, ensuring normal power supply to the converter's auxiliary power supply and load. When the converter stops, the isolating switch opens, and the power supply switching circuit allows the auxiliary power supply to draw power from the bus support capacitor, allowing the load connected to the auxiliary power supply output terminal to continue operating and consume the energy in the support capacitor. Typically, the main power-consuming equipment in a load is the cooling fan. Compared to adding a parallel resistor next to the busbar support capacitor to discharge the capacitor voltage to a safe voltage, which keeps the resistor in a high-temperature state for a long time, the cooling fan in the load not only does not increase the heat in the system, but also can dissipate the heat of the components in the cabinet to the environment in a timely manner after the converter is shut down, protecting the device safety and extending its life. Understandably, the auxiliary power supply should have a wide input range capability, be able to operate normally between the rated voltage of the DC bus and the safe voltage for human use, and be able to ensure the normal operation of the busbar support capacitor during discharge.

[0044] Therefore, this embodiment achieves bus support capacitor discharge by simply adding a power supply switching circuit and correspondingly improving the auxiliary power supply. The power supply switching circuit is connected to both the bus input terminal of the converter and the bus support capacitor. When the converter is operating normally, the auxiliary power supply obtains power from the bus input terminal of the converter through the first input terminal of the power supply switching circuit, ensuring normal power supply to the load on the converter. When the converter stops, the isolating switch is disconnected, and the controller switches the power input of the power supply switching circuit to the second input terminal. The auxiliary power supply then draws power from the bus support capacitor through the power supply switching circuit, controlling the load to continue running to consume the energy in the support capacitor, thus rationally recovering the energy in the bus support capacitor. This utility model, by simply adding a power supply switching circuit and improving the auxiliary power supply, utilizes the power supply circuit of the load in the original equipment of the converter to convert it into a circuit for discharging the bus support capacitor, solving the problem of discharging the bus support capacitor while controlling costs and without adding additional components.

[0045] In the above embodiment, the first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter to form a first loop; the second input terminal of the power supply switching circuit is connected to the bus support capacitor to form a second loop; the output terminal of the power supply switching circuit is connected to the input terminal of the load through an auxiliary power supply, used to disconnect the first loop and connect the second loop when the disconnecting switch is open. Since the converter input voltage may be DC or AC, this embodiment provides different power supply switching circuit implementations to handle different voltage inputs:

[0046] like Figure 2As shown, in one specific embodiment, the power supply switching circuit includes a single-pole double-throw relay; the first contact of the relay serves as the first input terminal of the power supply switching circuit and is connected to the bus input terminal of the converter; the second contact of the relay serves as the second input terminal of the power supply switching circuit and is connected to the bus support capacitor; the common contact of the relay serves as the output terminal of the power supply switching circuit and is connected to the input terminal of the load through an auxiliary power supply. In this specific embodiment, the converter can be a DC converter. When the disconnect switch is closed, the converter operates normally, and the voltage at the bus input terminal of the DC converter charges the bus support capacitor through the disconnect switch. Simultaneously, the bus support capacitor provides a stable DC voltage for subsequent circuits. At this time, the first circuit of the power supply switching circuit is in a power supply state, and the auxiliary power supply obtains energy from the converter bus input terminal to provide stable power support for the load. When the disconnect switch is open, the first circuit is disconnected, the power supply switching circuit operates, and the single-pole double-throw relay switches the connection to the second circuit, that is, obtains energy from the bus support capacitor. The electrical energy stored in the bus support capacitor is converted by the auxiliary power supply through the output terminal of the power supply switching circuit to continue providing power to the load. The electrical energy in the busbar support capacitor is efficiently recovered and utilized. In this process, the single-pole double-throw relay, as a relatively simple component with an intuitive operating principle, plays a crucial role. In DC circuits, it offers high reliability, rapidly responds to control signals, and enables switching between the first and second circuits. Furthermore, its cost is relatively low. For DC converter systems, selecting a single-pole double-throw relay effectively controls costs while meeting functional requirements.

[0047] like Figure 3As shown, in another specific embodiment, the power supply switching circuit includes: a first controllable switch and a second controllable switch; the first terminal of the first controllable switch serves as the first input terminal of the power supply switching circuit and is connected to the bus input terminal of the converter; the first terminal of the second controllable switch serves as the second input terminal of the power supply switching circuit and is connected to the bus support capacitor; the second terminals of the first and second controllable switches are connected, and their common terminal serves as the output terminal of the power supply switching circuit and is connected to the input terminal of the load. In a specific embodiment, the converter can be an AC converter. When the disconnect switch is closed, the voltage at the bus input terminal of the AC converter charges the bus support capacitor through the disconnect switch. The bus support capacitor serves as a filter and stores some energy. At this time, the first controllable switch in the power supply switching circuit is closed, allowing AC power to supply the load from the bus input terminal through the auxiliary power supply. The auxiliary power supply converts the AC input into the power form required by the load, such as a stable DC voltage. When the disconnect switch is open, the first controllable switch is opened, and the second controllable switch is closed. The energy stored in the bus support capacitor provides short-term power support to the load through the second controllable switch and the auxiliary power supply. Understandably, due to the characteristics of AC, factors such as capacitor discharge and AC signal phase need to be considered in this process to ensure that the load can receive appropriate transitional power.

[0048] In AC circuits, two relatively independent controllable switches can precisely control two separate loops. The on and off times of the switches can be flexibly set based on the phase, amplitude, and other characteristics of the AC signal, better adapting to changes in the AC input. For example, switching loops near the zero-crossing point of the AC input can reduce current surges and electromagnetic interference during the switching process.

[0049] At the same time, the converter can also be a DC converter, regardless of whether the input voltage is DC or AC. Furthermore, the two controllable switches can be easily integrated with other AC control circuits, such as voltage detection circuits and power factor correction circuits, to enhance the adaptability and control function of the entire converter system to current input.

[0050] Therefore, in this embodiment, when the power supply switching circuit is a single-pole double-throw relay, the converter can have a DC input; when the power supply switching circuit is a first controllable switch and a second controllable switch, the converter can have either a DC or AC input. Since the current direction is constant in a DC circuit, the contact switching action of the single-pole double-throw relay is simple and direct. When the isolating switch is open, the relay switches to the circuit powered by the bus support capacitor, stably providing DC power to the load. In a DC environment, the relay contacts mainly consider factors such as contact resistance and rated current, which are relatively easy to meet the requirements of DC circuits. However, in an AC circuit, the voltage direction changes periodically, which places stringent requirements on the timing of switching, making smooth switching impossible. There is also the possibility of AC / DC voltage superposition causing operational overvoltage, resulting in permanent damage to the relay. Two relatively independent controllable switches can better adapt to the switching between AC and DC circuits, allowing AC / DC input to be switched on only after the DC / AC input has been disconnected, ensuring complete independence between the two inputs.

[0051] In the above embodiment, the output terminal of the power supply switching circuit is connected to the input terminal of the load through an auxiliary power supply. The first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter, and the second input terminal of the power supply switching circuit is connected to the bus support capacitor. There is a significant voltage difference between the voltage output from the bus input terminal of the converter and the voltage output from the bus support capacitor, which places high demands on the operating voltage range of the auxiliary power supply. Therefore, this embodiment further explains and optimizes the technical solution. Specifically: the auxiliary power supply includes a first auxiliary power supply and a second auxiliary power supply; the first terminal of the first auxiliary power supply is connected to the output terminal of the power supply switching circuit, and the second terminal of the first auxiliary power supply is connected to the input terminal of the load, used to supply power to the load using the bus input terminal of the converter; the first terminal of the second auxiliary power supply is connected to the output terminal of the power supply switching circuit, and the second terminal of the second auxiliary power supply is connected to the input terminal of the load, used to supply power to the load using the electrical energy of the bus support capacitor.

[0052] In this embodiment, the auxiliary power supply is divided into a first auxiliary power supply and a second auxiliary power supply, each of which can be optimized for different voltage ranges. The first auxiliary power supply is mainly used to handle the higher voltage at the converter bus input. It can be configured with circuit parameters based on the higher voltage range, such as selecting electronic components with appropriate withstand voltage values, according to the bus rated voltage. The second auxiliary power supply focuses on utilizing the energy of the bus support capacitor. Since the voltage of the bus support capacitor gradually decreases during discharge, its voltage range may be closer to the human body's safe voltage. The second auxiliary power supply can be designed for this lower voltage range, using a low-dropout linear regulator or a DC-DC converter suitable for low voltage input. When handling high voltage input, the first auxiliary power supply can use a topology suitable for high voltage conversion, such as a push-pull converter or a forward converter. These topologies can achieve high power conversion efficiency under high voltage input conditions through reasonable duty cycle control and transformer coupling. For the discharge of the lower voltage bus support capacitor, the second auxiliary power supply can use a high-efficiency low-voltage conversion circuit, such as a synchronous buck converter. Synchronous buck converters reduce the forward voltage drop losses of diodes in traditional rectification methods through synchronous rectification technology, and can maintain high conversion efficiency at low voltage input.

[0053] Therefore, dividing the auxiliary power supply into a primary auxiliary power supply and a secondary auxiliary power supply allows the overall auxiliary power supply to better adapt to a wide input range, from the rated DC bus voltage to the safe voltage for human use. Compared to the complexity of a single auxiliary power supply simultaneously handling both high and low voltage inputs, two auxiliary power supplies can operate efficiently within their respective voltage ranges, reducing the circuit design difficulties and component selection challenges that may arise from an excessively wide voltage range. This improves the overall adaptability and stability of the auxiliary power supply to different input voltages. The two auxiliary power supplies employ different high-efficiency conversion circuits based on their different input voltage ranges, thereby improving the overall efficiency of the auxiliary power supply across the entire wide voltage input range. At different operating stages, they can efficiently convert input electrical energy into the electrical energy required by the load, reducing energy loss and improving energy utilization.

[0054] In the above embodiment, the output terminal of the power supply switching circuit is connected to the input terminal of the load via an auxiliary power supply. The first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter, and the second input terminal of the power supply switching circuit is connected to the bus support capacitor. Since the converter input voltage may be DC or AC, and the bus support capacitor outputs a DC signal, this embodiment further explains and optimizes the technical solution to accommodate different voltage inputs. Specifically, the auxiliary power supply is an AC / DC hybrid power supply.

[0055] In this embodiment, the AC / DC hybrid power supply can automatically identify whether the input is AC or DC. For AC input, it can convert AC to DC through its internal rectifier circuit; for DC input, it can directly perform the corresponding voltage processing. This automatic adaptive feature allows the auxiliary power supply to operate normally regardless of whether the converter input is AC or DC, without the need for additional complex switching circuits to distinguish between AC and DC inputs. This power supply is designed to better handle a wide range of input voltages. Because its internal circuitry can handle both AC and DC simultaneously, it can comprehensively consider the changing characteristics of AC and DC voltages to optimize the circuitry. For example, when handling DC input, a high-efficiency buck or boost circuit can be used for the DC voltage range; for AC input, appropriate filtering and voltage regulation circuits can be set in the DC stage after rectification to adapt to different AC RMS input ranges. At the same time, using the AC / DC hybrid power supply as a single auxiliary power supply reduces the number of components and complex connections in the circuit compared to setting up separate power conversion circuits for AC and DC. It integrates AC conversion and DC conversion functions into a single power module, reducing system space occupation and wiring complexity. In addition, hybrid AC / DC converters typically have good dynamic response characteristics. When the type or voltage of the input power supply changes suddenly, such as switching from AC to DC, or when the amplitude of the input voltage changes abruptly, the control circuit inside the hybrid AC / DC converter can react quickly.

[0056] Therefore, it is evident that in the actual operation of a converter, the input voltage may fluctuate significantly between the rated DC bus voltage and the safe voltage for human use. A hybrid AC / DC converter can better adapt to this wide range of variations. Through its internal automatic adjustment mechanism, the hybrid AC / DC converter can effectively convert the input voltage to a stable output voltage suitable for the load under different input voltage levels, improving the auxiliary power supply's adaptability to input voltage fluctuations. Using a hybrid AC / DC converter as an auxiliary power supply can greatly simplify the system's circuit structure, improve the system's compatibility with different input power types, and reduce the risk of system failures caused by changes in input power type. Furthermore, the hybrid AC / DC converter can ensure a stable power supply to the load even when the input power is unstable or the converter's operating state changes frequently, reducing load malfunctions caused by power fluctuations and improving the overall performance of the converter system.

[0057] Compared to the previous embodiment, this embodiment further explains and optimizes the technical solution. For example... Figure 4 As shown, this embodiment also discloses a specific voltage sampling circuit; the input terminal of the voltage sampling circuit is connected to the bus support capacitor and is used to detect the voltage of the bus support capacitor.

[0058] In this embodiment, by connecting the input terminal of the voltage sampling circuit to the bus support capacitor, the voltage information of the bus support capacitor can be obtained in real time. The voltage of the bus support capacitor is an important indicator of the operating status of the converter system. During normal operation, its voltage will be maintained within a relatively stable range, which is closely related to the input voltage of the converter, the load condition, and the energy storage and release status of the system. When a fault occurs in the system, such as abnormal input voltage, sudden load change, or circuit component failure, the voltage of the bus support capacitor will change accordingly. The power supply switching circuit is controlled and switched based on the voltage value of the bus support capacitor detected by the voltage sampling circuit.

[0059] In conjunction with this, the present invention also discloses a specific controller; the input terminal of the controller is connected to the bus support capacitor through a voltage sampling circuit to obtain the voltage of the bus support capacitor detected by the voltage sampling circuit; the output terminal of the controller is connected to the control input terminal of the power supply switching circuit to send control signals of the switching circuit based on the voltage of the bus support capacitor and the opening and closing state of the disconnecting switch.

[0060] In this embodiment, the controller can energize the relay coil or turn on the control circuit in the power supply switching circuit based on the voltage value of the bus support capacitor detected by the voltage sampling circuit. The auxiliary power supply draws power from the bus support capacitor, and the controller controls the fan and other components to continue operating to consume the energy in the support capacitor. When the capacitor voltage is lower than the safe voltage, the controller de-energizes the DC relay coil or disconnects the control circuit, and the auxiliary power supply continues to draw power from the DC input terminal, ensuring the normal operation of the energy storage converter auxiliary system and the control system.

[0061] Therefore, the switching mechanism based on the controller and voltage sampling circuit in this embodiment avoids the untimely or inaccurate operation of manual operation, effectively improving the stability of the system when switching between different operating states. In this way, the energy stored in the bus support capacitor can be utilized more fully, effectively protecting key components in the system, such as the bus support capacitor itself, auxiliary power supply, and load. Timely control actions can prevent component damage due to overvoltage, overcurrent, or other abnormal conditions, reducing system maintenance costs and downtime, and improving system safety and service life.

[0062] In the above embodiments, in addition to connecting the second input terminal of the power supply switching circuit to the bus support capacitor to form a second circuit for discharging the bus support capacitor, this utility model also discloses a specific bleedering circuit. The bleedering circuit is connected in parallel across the two ends of the bus support capacitor, and its input terminal is connected to the controller for turning on or off based on the controller's instructions. When the disconnecting switch is open, if the power supply switching circuit malfunctions or the load discharge alone is insufficient to reduce the voltage of the bus support capacitor within a predetermined time, the bleedering circuit can be connected to the system to discharge the bus support capacitor. In this case, the bleedering circuit provides a safe discharge channel for the bus support capacitor. It can actively consume the energy stored in the capacitor, gradually reducing the voltage across the bus support capacitor to a safe range, ensuring the personal safety of maintenance personnel and the safe use of the circuit.

[0063] In a specific implementation, the discharge circuit may include a discharge resistor and a third controllable switch. The discharge resistor and the third controllable switch are connected in series as a whole and in parallel across the busbar support capacitor. The control terminal of the third controllable switch serves as the input terminal of the discharge circuit and is connected to the controller. When it is necessary to discharge the busbar support capacitor, the third controllable switch is turned on, forming a discharge circuit between the discharge resistor and the busbar support capacitor. Since the controllable switch can control its on and off times according to actual needs, the start time, duration, and discharge speed of the discharge can be flexibly adjusted. The third controllable switch can be in the off state under normal circumstances to prevent the discharge resistor from accidentally connecting to the circuit and causing unnecessary energy loss of the busbar support capacitor. At the same time, when discharge is required, by reasonably controlling the third controllable switch and the discharge resistor, safety hazards such as overheating and arcing due to excessive discharge current can be avoided. In addition, when the discharge circuit itself malfunctions, such as a short circuit in the discharge resistor, the controllable switch can promptly cut off the circuit to prevent the fault from escalating.

[0064] Therefore, adding a bleeder circuit can prevent other equipment from being damaged by prolonged exposure to excessively high voltage. The bleeder circuit effectively prevents this from happening, extends the lifespan of equipment, and improves system reliability. It ensures a stable voltage environment during each system startup, which is beneficial for the normal startup and operation of all system devices. The bleeder circuit composed of a third controllable switch and a bleeder resistor is relatively simple, and this flexibility allows it to better adapt to various situations. Furthermore, when a problem occurs in the bleeder circuit, troubleshooting is convenient. By checking the status of the controllable switch and whether the resistance value of the bleeder resistor is normal, the fault point can be quickly located. Moreover, during maintenance, the controllable switch and bleeder resistor can be replaced or repaired individually without affecting other parts of the circuit.

[0065] Finally, this embodiment provides a power supply device, including the converter described above.

[0066] The converter and power supply equipment provided in this application have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably.

[0067] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A converter, comprising a disconnecting switch and a bus support capacitor, characterized in that, Also includes: Power supply switching circuit, auxiliary power supply; The disconnecting switch is located between the bus input terminal of the converter and the bus support capacitor; The first input terminal of the power supply switching circuit is connected to the bus input terminal of the converter to form a first circuit; the second input terminal of the power supply switching circuit is connected to the bus support capacitor to form a second circuit; the output terminal of the power supply switching circuit is connected to the input terminal of the load through the auxiliary power supply, and is used to disconnect the first circuit and connect the second circuit when the disconnecting switch is opened.

2. The converter according to claim 1, characterized in that, The power supply switching circuit includes a single-pole double-throw relay; The first contact of the relay is connected to the bus input terminal of the converter as the first input terminal of the power supply switching circuit. The second contact of the relay is connected to the bus support capacitor as the second input terminal of the power supply switching circuit. The common contact of the relay serves as the output terminal of the power supply switching circuit and is connected to the input terminal of the load via the auxiliary power supply.

3. The converter according to claim 1, characterized in that, The power supply switching circuit includes: a first controllable switch and a second controllable switch; The first terminal of the first controllable switch is connected to the bus input terminal of the converter as the first input terminal of the power supply switching circuit. The first terminal of the second controllable switch is connected to the bus support capacitor as the second input terminal of the power supply switching circuit. The second terminal of the first controllable switch is connected to the second terminal of the second controllable switch, and their common terminal is connected to the input terminal of the load as the output terminal of the power supply switching circuit.

4. The converter according to claim 1, characterized in that, The auxiliary power supply includes: a first auxiliary power supply and a second auxiliary power supply; The first terminal of the first auxiliary power supply is connected to the output terminal of the power supply switching circuit, and the second terminal of the first auxiliary power supply is connected to the input terminal of the load, so as to supply power to the load using the bus input terminal of the converter; The first end of the second auxiliary power supply is connected to the output end of the power supply switching circuit, and the second end of the second auxiliary power supply is connected to the input end of the load, so as to use the electrical energy of the bus support capacitor to supply power to the load.

5. The converter according to claim 1, characterized in that, The auxiliary power supply is an AC / DC hybrid power supply.

6. The converter according to any one of claims 1 to 5, characterized in that, Also includes: Voltage sampling circuit; The input terminal of the voltage sampling circuit is connected to the busbar support capacitor and is used to detect the voltage of the busbar support capacitor.

7. The converter according to claim 6, characterized in that, Also includes: Controller; The input terminal of the controller is connected to the bus support capacitor through the voltage sampling circuit, and is used to obtain the voltage of the bus support capacitor detected by the voltage sampling circuit; The output terminal of the controller is connected to the control input terminal of the power supply switching circuit, and is used to send control signals of the switching circuit based on the voltage of the bus support capacitor and the open / closed state of the disconnecting switch.

8. The converter according to claim 7, characterized in that, Also includes: Bleeding circuit; The discharge circuit is connected in parallel across the two ends of the busbar support capacitor, and the input terminal of the discharge circuit is connected to the controller for turning on or off based on the controller's command.

9. The converter according to claim 8, characterized in that, The discharge circuit includes: a discharge resistor and a third controllable switch; The bleeder resistor and the third controllable switch are connected in series as a whole and then connected in parallel across the two ends of the busbar support capacitor. The control terminal of the third controllable switch is connected to the controller as the input terminal of the bleeder circuit.

10. A power supply device, characterized in that, Includes the converter as described in any one of claims 1 to 9.

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