Digital current sharing method of power supply parallel system based on CAN communication

Abstract

The invention discloses a digital current sharing method of a power supply parallel system based on CAN (Controller Area Network) communication, relates to the technical field of digital current sharing, and solves the problem that all parallel power supply modules easily fail at the same time due to the failure of any one of the power supply modules when the existing digital current sharing method of the power supply modules is used for balancing current. In order to solve the problem that all power supply modules are damaged due to the fact that fault causes or fault modules are difficult to find in time, the method comprises the following steps: collecting current data of each power supply module, and comparing each current by using a current comparator; selecting a power supply module with peak current as a main module; a current amplifier is used to equalize the current value of each power supply module. According to the invention, when each power supply module breaks down, the main module can be quickly switched and the power supply module can be quickly cut off, so that the main module or the power supply module which breaks down is prevented from influencing all the other power supply modules.

Description

Technical Field

[0001] The invention relates to the technical field of digital current sharing, and in particular to a digital current sharing method for a power supply parallel system based on CAN communication. Background Art

[0002] In the field of communication power supply, it is a very important technology to use multiple power modules in parallel to achieve high power output. Power parallel connection has the advantages of centralized power supply management, easy expansion, good compatibility, redundant backup, high reliability, and high cost performance. Due to its strong advantages, it has radiated and promoted the research, progress and development of power module parallel connection technology in the entire power supply field. Power parallel connection technology has become the core technology of high-power distributed power supply system, and the core of realizing power parallel operation is current sharing technology;

[0003] Current balancing technology refers to the measure of evenly distributing the load current of each power module in a system with multiple power modules in parallel. It requires that each module can withstand self-balancing of current, while maintaining stable output voltage when input voltage and load current change, and having good current balancing accuracy and transient response.

[0004] The existing digital current balancing method for power modules is prone to cause all parallel power modules to fail simultaneously due to the failure of any one of the power modules when balancing the current, and it is difficult to find the cause of the failure or the faulty module in time, resulting in damage to all power modules; therefore, it does not meet the existing needs. In this regard, we propose a digital current balancing method for power parallel systems based on CAN communication. Summary of the invention

[0005] The purpose of the present invention is to provide a digital current equalizing method for a power parallel system based on CAN communication, so as to solve the problem that when balancing the current, the digital current equalizing method of the existing power module proposed in the above background technology is easy to cause all parallel power modules to fail at the same time due to the failure of any one of the power modules, and it is difficult to detect the cause of the failure or the faulty module in time, resulting in damage to all power modules.

[0006] To achieve the above object, the present invention provides the following technical solution: a digital current sharing method for a power parallel system based on CAN communication, comprising the following steps:

[0007] Step A: Use sampling resistors and current sensors to collect current data of each power module, transmit it to the control host using the CAN bus, and use a current comparator to compare each current;

[0008] Step B: Select the power module with the peak current of the maximum current as the main module according to the data frame format transmitted by the CAN communication system, and use the current monitoring module to monitor the current value of the main module in real time. When the current value of the main module fluctuates unstably, abandon the main module and perform step A again to select the main module from the remaining power modules;

[0009] Step C: The main module transmits its own current and ID data to the CAN communication system, and uses the control host and the CAN communication system to cooperate with the current amplifier to adjust the current value of each power module of the non-main module to the selected peak current.

[0010] Preferably, the power parallel system based on CAN communication consists of a control host and multiple power modules. The CAN communication system is installed in the control host, and each power module is connected in parallel.

[0011] Preferably, the output end of each power module is provided with a communication interface, the outer end of the communication interface is connected to a CAN bus, and the CAN bus is connected to a control host.

[0012] Preferably, a current monitoring module is provided on the surface of the power module, and the power module is electrically connected to the current monitoring module.

[0013] Preferably, the current monitoring module includes a current sensor, a current comparator and a sampling resistor, and a current amplifier is provided on the surface of the control host.

[0014] Preferably, the current comparators in step A are respectively connected to each power module, and the current sensors are built in each power module.

[0015] Preferably, when the main module is selected in step B, when there are multiple power modules with the same peak current, the identity codes written into the CAN communication system of each power module with the same peak current are compared, and the power module with the smallest identity code is selected as the main module.

[0016] Preferably, the address data frame format of the identity code written using the CAN communication system complies with a specified format specification.

[0017] Preferably, the identity code address data frame format written by the CAN communication system consists of a start segment, an arbitration segment, a control segment, a data field, a CRC segment, a response segment and an end segment, wherein the minimum unit of the number of data bits transmitted in each segment is a CDM bit.

[0018] Preferably, each power module in step B is connected to an alarm module, and the real-time monitoring process of the current monitoring module in step B includes the following steps:

[0019] S1: First, use the power monitoring module to monitor the current of the main module in real time, and transmit the peak current of the main module in real time through the CAN communication system. When the current value of the main module fluctuates unstably, select a new power module from the remaining power modules as the main module;

[0020] S2: Use the power monitoring module to monitor the current of other power modules in real time. When other power modules fail or the current fluctuates unstably, disconnect the CAN bus, control power supply and other connected components in time, shut down the failed power module in time, and eliminate the failed power module.

[0021] S3: The alarm module is then used to quickly alert the staff, so that the staff can check the location of the faulty power module and ensure the normal operation of the system while facilitating repair and maintenance.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention monitors the current of the main module and the remaining power modules in real time through a power monitoring module. When the current value of the main module fluctuates unstably, the main module is abandoned and a main module is selected from the remaining power modules, so that the currents of the remaining power modules except the faulty power module are adjusted to be consistent with the current of the new main module, thereby avoiding the influence of the faulty main module or power module on all the remaining power modules, and quickly alarming the staff through the alarm module, so that the staff can quickly find the cause of the fault and repair the cause of the fault to ensure the normal operation of the system and avoid damage to the power module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall process of the present invention;

[0025] Figure 2 It is a flow chart of the digital current sharing method of the present invention;

[0026] Figure 3 It is a partial structural schematic diagram of the power module of the present invention;

[0027] Figure 4 It is a schematic diagram of the power parallel system based on CAN communication of the present invention;

[0028] Figure 5 It is a flowchart of the implementation method of the alarm module of the present invention;

[0029] Figure 6 It is a schematic diagram of the structure of the power module of the present invention. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0031] See also Figure 1 to Figure 2 , an embodiment provided by the present invention: a digital current sharing method for a power supply parallel system based on CAN communication, comprising the following steps:

[0032] Step A: Use sampling resistors and current sensors to collect current data of each power module, transmit it to the control host using the CAN bus, and use a current comparator to compare each current;

[0033] Step B: Select the power module with the peak current of the maximum current as the main module according to the data frame format transmitted by the CAN communication system, and use the current monitoring module to monitor the current value of the main module in real time. When the current value of the main module fluctuates unstably, abandon the main module and perform step A again to select the main module from the remaining power modules;

[0034] Step C: The main module transmits its own current and ID data to the CAN communication system, and uses the control host and the CAN communication system to cooperate with the current amplifier to adjust the current value of each power module of the non-main module to the selected peak current.

[0035] See also Figure 3 and Figure 4 The power parallel system based on CAN communication consists of a control host and multiple power modules. The CAN communication system is installed in the control host, and each power module is connected in parallel.

[0036] The output end of each power module is provided with a communication interface, the outer end of the communication interface is connected to a CAN bus, and the CAN bus is connected to a control host.

[0037] See also Figure 6 A current monitoring module is provided on the surface of the power module, and the power module is electrically connected to the current monitoring module.

[0038] The current monitoring module includes a current sensor, a current comparator and a sampling resistor, and a current amplifier is arranged on the surface of the control host.

[0039] The current comparators in step A are connected to each power module respectively, and the current sensors are built in each power module.

[0040] When selecting the main module in step B, when there are multiple power modules with the same peak current, the identity codes written into the CAN communication system of each power module with the same peak current are compared, and the power module with the smallest identity code is selected as the main module.

[0041] See also Figure 5 The address data frame format of the identity code written using the CAN communication system follows the specified format specification.

[0042] The identity code address data frame format written by the CAN communication system consists of a start segment, an arbitration segment, a control segment, a data field, a CRC segment, a response segment and an end segment, wherein the minimum unit of the number of data bits transmitted in each segment is a CDM bit.

[0043] In step B, each power module is connected to an alarm module, and the real-time monitoring process of the current monitoring module in step B includes the following steps:

[0044] S1: First, use the power monitoring module to monitor the current of the main module in real time, and transmit the peak current of the main module in real time through the CAN communication system. When the current value of the main module fluctuates unstably, select a new power module from the remaining power modules as the main module;

[0045] S2: Use the power monitoring module to monitor the current of other power modules in real time. When other power modules fail or the current fluctuates unstably, disconnect the CAN bus, control power supply and other connected components in time, shut down the failed power module in time, and eliminate the failed power module.

[0046] S3: The alarm module is then used to quickly alert the staff, so that the staff can check the location of the faulty power module and ensure the normal operation of the system while facilitating repair and maintenance.

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A digital current sharing method for a power parallel system based on CAN communication, characterized in that: The steps include: Step A: Use sampling resistors and current sensors to collect current data of each power module, transmit it to the control host using the CAN bus, and use a current comparator to compare each current; Step B: Select the power module with the peak current of the maximum current as the main module according to the data frame format transmitted by the CAN communication system, and use the current monitoring module to monitor the current value of the main module in real time. When the current value of the main module fluctuates unstably, abandon the main module and perform step A again to select the main module from the remaining power modules; Step C: The main module transmits its own current and ID data to the CAN communication system, and uses the control host and the CAN communication system to cooperate with the current amplifier to adjust the current value of each power module of the non-main module to the selected peak current.

2. According to claim 1, a digital current sharing method for a power supply parallel system based on CAN communication is characterized in that: The power parallel system based on CAN communication consists of a control host and multiple power modules. The CAN communication system is installed in the control host, and each power module is connected in parallel.

3. According to claim 1, a digital current sharing method for a power supply parallel system based on CAN communication is characterized in that: The output end of each power module is provided with a communication interface, the outer end of the communication interface is connected to a CAN bus, and the CAN bus is connected to a control host.

4. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 1, characterized in that: A current monitoring module is disposed on the surface of the power module, and the power module is electrically connected to the current monitoring module.

5. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 1, characterized in that: The current monitoring module includes a current sensor, a current comparator and a sampling resistor, and a current amplifier is arranged on the surface of the control host.

6. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 1, characterized in that: The current comparators in step A are respectively connected to each power module, and the current sensors are built in each power module.

7. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 1, characterized in that: When the main module is selected in step B, when there are multiple power modules with the same peak current, the identity codes written into the CAN communication system of each power module with the same peak current are compared, and the power module with the smallest identity code is selected as the main module.

8. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 7, characterized in that: The address data frame format of the identity code written using the CAN communication system follows the specified format specification.

9. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 8, characterized in that: The identity code address data frame format written by the CAN communication system consists of a start segment, an arbitration segment, a control segment, a data field, a CRC segment, a response segment and an end segment, wherein the minimum unit of the number of data bits transmitted in each segment is a CDM bit.

10. The digital current sharing method of a power supply parallel system based on CAN communication according to claim 1, characterized in that: In step B, each power module is connected to an alarm module, and the real-time monitoring process of the current monitoring module in step B includes the following steps: S1: First, use the power monitoring module to monitor the current of the main module in real time, and transmit the peak current of the main module in real time through the CAN communication system. When the current value of the main module fluctuates unstably, select a new power module from the remaining power modules as the main module; S2: Use the power monitoring module to monitor the current of other power modules in real time. When other power modules fail or the current fluctuates unstably, disconnect the CAN bus, control power supply and other connected components in time, shut down the failed power module in time, and eliminate the failed power module. S3: The alarm module is then used to quickly alert the staff, so that the staff can check the location of the faulty power module and ensure the normal operation of the system while facilitating repair and maintenance.

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