A direct current converter automatic wake-up device

Abstract

The application discloses a kind of direct current converter automatic wake-up device, it is related to direct current converter field, the direct current converter automatic wake-up device is used in direct current system;Multiple converters in direct current system are connected with load side by direct current bus;Direct current converter automatic wake-up device, comprising: coupling inductance and transmitter;Coupling inductance is arranged on direct current bus;Transmitter is connected with coupling inductance and each converter respectively;When load side increases the load of set amount in set time, the rate of change of current flowing through direct current bus is greater than or equal to set current rate of change value, coupling inductance generates induced current, transmitter modulates induced current into voltage signal, to control the converter in dormant state in direct current system enters working state.The application can improve the wake-up speed of converter.

Description

Technical Field

[0001] This invention relates to the field of DC-DC converters, and in particular to an automatic wake-up device for DC-DC converters. Background Technology

[0002] To meet the power requirements of a DC system, the DC-DC converters used must be power-calibrated. Since the system will not operate at full load for extended periods, this would result in significant power waste. Therefore, multiple low-power converter modules are widely used to power the system. Multiple converter modules are engaged when the load is high, while the number of modules is reduced and put into standby mode when the load is low. Based on this, it is necessary to quickly wake up the converter modules when the load increases; otherwise, the DC system will experience voltage drops due to insufficient power.

[0003] Currently, the most widely used methods for waking up converter modules are either manually issuing commands in advance, or the converter's host computer sampling the load side and calculating the load-side power to determine whether the converter module needs to be woken up. If wake-up is required, a communication command is sent to the converter, which then wakes up and begins operation upon receiving the command. For example, patent application number 202110760699.1 describes waking up a DC / DC converter in an electric vehicle by issuing commands via CAN communication. A significant drawback of this method is that it requires manual operation and lacks speed; communication delays are typically tens to hundreds of milliseconds, and the slow wake-up process can lead to DC system instability, thus rendering it unsuitable for DC systems. Patent application number 202220028190.8 describes using impedance voltage division in a battery management system to obtain the wake-up voltage, applying appropriate impedance calculations to different wake-up voltage scenarios. The disadvantages of this method are that the impedance is directly connected to the bus, which may damage the controlled object in the event of a fault, and the wake-up speed needs improvement. Furthermore, the losses caused by the connected resistance are not negligible, significantly reducing transmission efficiency. It is evident that currently, the converter module is woken up using communication wake-up, which is limited by latency and has a relatively slow wake-up speed. Summary of the Invention

[0004] Based on this, embodiments of the present invention provide an automatic wake-up device for a DC converter to improve the wake-up speed.

[0005] To achieve the above objectives, embodiments of the present invention provide the following solutions:

[0006] An automatic wake-up device for a DC converter is provided for use in a DC system; the DC system includes multiple converters; the multiple converters are connected to the load side via a DC bus;

[0007] The DC-DC converter automatic wake-up device includes: a coupling inductor and a transmitter;

[0008] The coupling inductor is disposed on the DC bus; the transmitter is connected to the coupling inductor and each of the converters respectively;

[0009] When the load side increases the load by a set amount within a set time, the rate of change of the current flowing through the DC bus is greater than or equal to the set rate of change of the current. The coupling inductor generates an induced current, and the transmitter modulates the induced current into a voltage signal to control the converter in the DC system that is in a dormant state to enter the working state.

[0010] Optionally, the coupled inductor includes: a primary-side inductor and a secondary-side inductor;

[0011] The primary inductor is connected in series on the DC bus; the secondary inductor is electromagnetically coupled to the primary inductor; the transmitter is connected to the secondary inductor.

[0012] Optionally, for a converter with a rated voltage of 375V and a rated current of 20A, the inductance value of the primary inductor ranges from 50uH to 1mH, and the inductance value of the secondary inductor ranges from 100uH to 5mH.

[0013] Optionally, for a converter with a rated voltage of 375V and a rated current of 20A, the inductance of the primary inductor is 0.1mH and the inductance of the secondary inductor is 1mH.

[0014] Optionally, the set change rate value is 10A / ms.

[0015] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0016] This invention proposes an automatic wake-up device for a DC-DC converter. By setting a coupling inductor on the DC bus to detect changes in the load current, the converter is automatically woken up. This is a wake-up method that is directly controlled by electrical quantities, without relying on communication, resulting in higher reliability and faster operation. It can improve the wake-up speed of the converter. Furthermore, the inductor is a non-energy-consuming component, and its loss under stable DC conditions is only the loss caused by its own parasitic resistance. When wake-up is not needed, it can reduce losses and improve system efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural diagram of the automatic wake-up device for a DC-DC converter provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] See Figure 1 The DC converter automatic wake-up device in this embodiment is used in a DC system; the DC system includes multiple converters; the multiple converters are connected to the load side through a DC bus.

[0022] The DC-DC converter automatic wake-up device includes: a coupling inductor 4 and a transmitter.

[0023] The coupling inductor 4 is disposed on the DC bus; the transmitter is connected to the coupling inductor 4 and each of the converters respectively.

[0024] When the load side increases the load by a set amount within a set time, the rate of change of the current flowing through the DC bus is greater than or equal to the set current rate of change value. The coupling inductor 4 generates an induced current, and the transmitter modulates the induced current into a voltage signal. Since the rate of change of the current flowing through the DC bus is greater than or equal to the set current rate of change value, the voltage signal is greater than or equal to the voltage threshold. The transmitter sends the voltage signal to each converter in the sleep state, thereby controlling the converters in the sleep state in the DC system to enter the working state. Figure 1 In the diagram, solid lines represent energy lines, and dashed lines represent signal lines, all of which are wired connections. When the transmitter senses a voltage signal greater than or equal to the voltage threshold, it directly outputs a control signal to wake up the converter via the signal lines.

[0025] In one example, the coupling inductor 4 includes a primary-side inductor and a secondary-side inductor. The primary-side inductor is connected in series with the DC bus; the secondary-side inductor is electromagnetically coupled to the primary-side inductor; and the transmitter is connected to the secondary-side inductor. This embodiment uses inductive coupling to generate a wake-up signal, which is an isolated wake-up method. Faults on the primary side will not directly affect the secondary side, ensuring the safety of personnel and equipment.

[0026] In one example, for a converter with a rated voltage of 375V and a rated current of 20A, the inductance value of the primary inductor ranges from 50uH to 1mH, and the inductance value of the secondary inductor ranges from 100uH to 5mH. For example, the inductance value of the primary inductor can be selected as 0.1mH, and the inductance value of the secondary inductor can be selected as 1mH. The set rate of change can be selected as 10A / ms.

[0027] Currently, the most widely used communication-based wake-up method is limited by latency, resulting in a slow wake-up speed. To address the slow startup problem in the automatic wake-up of multi-module DC-DC converters, the above embodiment proposes an automatic wake-up device for DC-DC converters. This device involves connecting an inductor in series with the DC bus and coupling it with another inductor. The rate of change of the current in the coupled inductor is used as the wake-up signal and sent to the dormant converter, ultimately activating the corresponding converter according to power requirements.

[0028] The above embodiments will be further described in detail below in conjunction with the implementation principles.

[0029] The purpose of automatic converter wake-up is to enable the converter to quickly and automatically switch from standby to operating state when a sudden external load is applied, thus rapidly supplying power to the load. When a sudden load is applied to the load side, the power increases rapidly, which is reflected in the electrical quantity of a rapid increase in current. Therefore, this can be used as the start condition for automatic wake-up. When the bus current flowing through the DC bus increases rapidly, it is considered that the load has increased, and the dormant device needs to be woken up.

[0030] The above embodiment can sense current changes by inserting a coupling inductor 4 in series on the bus. During normal operation, the system power is balanced, and a relatively stable DC current flows through the bus. At this time, the primary-side inductor has no effect, and there is no electromagnetic coupling between the primary and secondary inductors; the rate of change of current with time is approximately zero. When a sudden load is applied, the current rises instantaneously, and a rapidly rising current flows through the primary-side inductor in the bus, thereby generating a voltage signal in the secondary-side inductor through electromagnetic coupling. The inductance value can be set to reflect the signal magnitude generated at different current change rates. For example, the inductance value range can be determined based on the actual voltage and current conditions of the converter. The inductance should not be too large, resulting in a large voltage change when the load changes; the inductance should not be too small, leading to poor coupling. For example, for a converter with a rated voltage of 375V and a rated current of 20A, a feasible inductance value range is a primary-side inductance of 50uH-1mH and a secondary-side inductance of 100uH-5mH.

[0031] When the load is small, the power of a single-module converter is sufficient to support the increased load. When the load increases slowly, the number of converter modules to be woken up can be adjusted via communication. A small increase in load is one of the situations where the response is slow, reflected in the load current change rate. Using the current change rate as a criterion, a load current change rate less than 10A / ms can be considered a slow increase. In neither of these situations does the converter need to be woken up quickly and automatically. The small current change or long change time in these cases results in a small current change rate, which will not automatically wake up the converter, meeting the requirements. However, when a large load is suddenly applied (e.g., the load current change rate is greater than or equal to 10A / ms), the rapid change in current generates a large induced current in the coupling inductor 4. The transmitter modulates this induced current into a voltage signal, which can quickly wake up the equipment and meet the power requirements. The power of a single converter module can be used to set the threshold at which a sudden increase in load power requires waking up other converters. Then, an appropriate inductor size can be selected to adjust the response value. For example, for a single converter with a rated voltage of 375V and a rated current of 20A, the primary and secondary inductances are set to 0.1mH and 1mH, respectively. When a 4kW load is quickly applied (the primary current increases by 10A within 1ms), the secondary side induces a current change of 1A / ms, which is converted into a 5V voltage signal by the transmitter and sent to the converter.

[0032] Please see again Figure 1Taking three converters as an example, in practical applications, when the system is running under low load, only converter 1 is in the working state, while converters 2 and 3 are in the dormant state. If a large power demand suddenly comes into contact with the load side, a large current change will occur in the line. The coupling inductor 4 senses the current change and generates an induced current in the secondary inductor. The transmitter modulates the induced current into a voltage signal as a wake-up signal. When the rate of change of current meets a certain condition, i.e., when a large amount of load is suddenly connected, the voltage signal reaches the voltage threshold. The voltage signal is sent to the converter through the transmitter, waking up the dormant converter and putting it into the working state to meet the power demand of the load side. All three converters are connected to the transmitter and use the same wake-up signal. When the voltage signal reaches the voltage threshold, all connected converters are awakened.

[0033] The automatic wake-up device for DC-DC converters described in the above embodiment has the following advantages: Automatic wake-up of the converter by detecting load current changes through the series coupling inductor 4 is a wake-up method directly controlled by electrical quantities, eliminating the need for communication, resulting in higher reliability and faster operation. Generating a wake-up signal through inductive coupling is an isolated wake-up method; primary-side faults will not directly impact the secondary side, ensuring the safety of personnel and equipment. Inductors are energy-efficient components; under stable DC conditions, their losses are limited to their own parasitic resistance, reducing losses and improving system efficiency when wake-up is not required.

[0034] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0035] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An automatic wake-up device for a DC-DC converter, characterized in that, The DC-DC converter automatic wake-up device is used in a DC system; the DC system includes multiple converters; the multiple converters are connected to the load side via a DC bus; The DC-DC converter automatic wake-up device includes: a coupling inductor and a transmitter; The coupling inductor is disposed on the DC bus; the transmitter is connected to the coupling inductor and each of the converters respectively; When the load side increases the load by a set amount within a set time, the rate of change of the current flowing through the DC bus is greater than or equal to the set rate of change of the current. The coupling inductor generates an induced current, and the transmitter modulates the induced current into a voltage signal to control the converter in the DC system that is in a dormant state to enter the working state. The coupled inductor includes: a primary-side inductor and a secondary-side inductor; The primary inductor is connected in series on the DC bus; the secondary inductor is electromagnetically coupled to the primary inductor; the transmitter is connected to the secondary inductor.

2. The DC-DC converter automatic wake-up device according to claim 1, characterized in that, For a converter with a rated voltage of 375V and a rated current of 20A, the inductance value of the primary inductor ranges from 50uH to 1mH, and the inductance value of the secondary inductor ranges from 100uH to 5mH.

3. The DC-DC converter automatic wake-up device according to claim 2, characterized in that, For a converter with a rated voltage of 375V and a rated current of 20A, the inductance of the primary inductor is 0.1mH and the inductance of the secondary inductor is 1mH.

4. The DC-DC converter automatic wake-up device according to claim 1, characterized in that, The set current change rate is 10A / ms.

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