Bidirectional controllable direct current source monitoring module with inductance parameter detection

Abstract

The application relates to a bidirectional controllable direct current source monitoring module with impedance parameter detection, which comprises an EMI filter, two auxiliary power supplies, two core control units, a display control unit and an impedance parameter detection unit. The interface between the monitoring module and the power supply module is a double-redundancy CAN interface, a plurality of power supply modules are controlled in groups according to ID identification, meanwhile, the real-time performance of the CAN network is utilized to carry out current sharing control on the output currents of all the grouped power supply modules; when the monitoring module detects that a fault occurs in the power supply module through the CAN network, the fault module is timely eliminated from the group, and the output currents of other power supply modules in the group are changed, so that the parallel output currents remain unchanged; the monitoring module automatically limits the output current to be not more than the rated value of a single power supply module, so that the safety of equipment when the number of the remaining power supply modules in the group is insufficient is guaranteed, meanwhile, man-machine interaction and inductance and resistance parameter detection of a load winding can be realized.

Description

Technical Field

[0001] The present invention relates to a ship electrical technology, in particular to a bidirectional controllable direct current source monitoring module with resistance and inductance parameter detection. Background Art

[0002] Currently, marine bidirectional controllable DC power supplies are typically designed as discrete or modular components. Compared to discrete components, the modular structure of bidirectional controllable DC power supplies is easier to standardize and can easily be combined into power systems with varying power levels, improving system reliability. Its plug-in connection method also makes maintenance faster and more convenient. To enable bidirectional controllable DC power supply modules to be combined into power systems with varying power levels and achieve N+1 redundancy, the bidirectional controllable DC power supply requires comprehensive control, monitoring, and fault detection for each power module.

[0003] A bidirectional controllable DC source receives commands from a control device and provides controllable positive and negative DC current to windings with varying resistance and inductive loads, while maintaining real-time output current control accuracy. Therefore, to ensure accurate output current control under varying loads, the bidirectional controllable DC source also requires parameter detection of the load's inductance (L) and resistance (R). Summary of the Invention

[0004] To address the above problems, a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection is proposed. The bidirectional controllable DC source can comprehensively control, monitor and detect faults of each power module, while realizing human-computer interaction and detection of the inductance and resistance parameters of the load winding.

[0005] The technical solution of the present invention is: a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection, comprising an EMI filter, two auxiliary power supplies, two core control units, a display and control unit, and a resistance and inductance parameter detection unit;

[0006] The EMI filter is used to filter the three-phase alternating current, remove the interference of high-frequency pulses of the power grid on the power supply, and reduce the electromagnetic interference of the power supply itself on the input power grid;

[0007] The two auxiliary power supplies are used to convert the three-phase AC 380V output of the EMI filter into DC 24V to supply power to the two core control units respectively;

[0008] The two core control units are redundantly designed and are used to communicate externally via Ethernet or CAN bus to obtain the on / off and output current instructions of the control device and feedback the operating status of the bidirectional controllable DC source; internally, they communicate via RS485 to exchange data with the display and control unit and the resistance and inductance parameter detection unit;

[0009] The display and control unit includes a liquid crystal display and button control to realize the human-computer interaction interface display and panel button response, and at the same time communicates with the core control unit and the resistance-inductance parameter detection unit through the internal RS485 bus; the resistance-inductance parameter detection unit is used to detect the size of the load inductance and resistance. According to the received instructions, it controls the load relay at the output end of the external power module of the monitoring module, performs resistance-inductance parameter detection on the load in turn, and transmits the detection value back to the core control unit and the display and control unit through the internal RS485 communication.

[0010] Furthermore, the resistance-inductance parameter detection unit is internally configured with a 380V / 20V transformer as an excitation source. When receiving the resistance-inductance parameter detection instruction, it turns off all power supplies outside the resistance-inductance parameter detection unit, and connects the excitation source to the resistance-inductance load to be tested by closing the relay connected in series at both ends of the resistance-inductance load for testing. The inductance and resistance of the resistance-inductance load can be obtained by calculation.

[0011] Furthermore, the excitation source of the resistance-inductive parameter detection unit adds a 50Hz excitation voltage to the resistance-inductive load, and simultaneously detects the voltage and current at both ends of the resistance-inductive load and performs FFT transformation to obtain the amplitude and phase information of the voltage and current. The inductance and resistance of the resistance-inductive load can be obtained through calculation, as follows: Assume that the signal of the excitation source is f(t)=A0 cos(100πt+θ), A0 is the amplitude of the excitation source, and θ is the phase of the excitation source; taking 4 points sampled in one cycle as an example, the sampling time t is 1 / 200 second, then the wave series sampled under the action of the excitation source signal is x[0]=A cos(θ), x[1]=A cos(π / 2+θ), x[2]=A cos(π+θ), x[3]=A cos(3π / 2+θ), and A is the amplitude of the sampled wave;

[0012] Perform Fourier transform on the collected waveform under the action of the excitation source signal to obtain:

[0013] N is the number of sampling points in one cycle;

[0014] Only the fundamental wave content of K=1 is calculated as follows:

[0015]

[0016] Then the amplitude and phase of voltage and current are:

[0017] U(1)=2AU[cos(θ)U+j sin(θ)U]=R e (U)+jL m (U) (1)

[0018] I(1)=2AI[cos(θ)I+j sin(θ)I]=Re (I)+jL m (I) (2)

[0019] U(1) / I(1)=R+j2πfL (3)

[0020] Substituting equations (1) and (2) into equation (3), we get:

[0021]

[0022] Then the resistance value of the load is:

[0023]

[0024] The inductance of the load is:

[0025]

[0026] A bidirectional controllable DC source monitoring module with resistance-inductance parameter detection is used. The interface between the bidirectional controllable DC source monitoring module with resistance-inductance parameter detection and the power supply module is a dual-redundant CAN interface. The bidirectional controllable DC source monitoring module with resistance-inductance parameter detection controls multiple power supply modules in groups according to ID identifiers, and simultaneously utilizes the real-time nature of the CAN network to control the output current of all grouped power supply modules. When the bidirectional controllable DC source monitoring module with resistance-inductance parameter detection detects a power supply module failure through the CAN network, the faulty module is promptly removed from the group and the output current of other power supply modules in the group is changed to maintain the parallel output current unchanged. The bidirectional controllable DC source monitoring module with resistance-inductance parameter detection automatically limits the output current to no more than the rated value of a single power supply module to ensure equipment safety when the number of remaining power supply modules in the group is insufficient.

[0027] The beneficial effects of the present invention are as follows: the present invention has a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection, which enables the bidirectional controllable DC source to comprehensively control, monitor and detect faults of each power supply module while realizing human-computer interaction and inductance and resistance parameter detection of the load winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a principle block diagram of a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection according to the present invention;

[0029] Figure 2 A flow chart showing a human-computer interaction interface in a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection according to the present invention;

[0030] Figure 3This is a principle block diagram of the resistance-inductance parameter detection unit in the bidirectional controllable DC source monitoring module with resistance-inductance parameter detection of the present invention. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0032] like Figure 1 The following figure shows the functional block diagram of the monitoring module. The interface between the monitoring module and the power modules is a dual-redundant CAN interface (CAN3 and CAN4). The monitoring module can group and control multiple power modules based on their IDs, dividing up to 24 power modules into six output groups. It also leverages the real-time nature of the CAN network to balance the output current of all grouped power modules. If the monitoring module detects a power module failure via the CAN network, it promptly removes the faulty module from the group and adjusts the output current of the remaining power modules in the group to maintain the parallel output current. The monitoring module automatically limits the output current to the rated value of a single power module to ensure equipment safety if the number of remaining power modules in the group is insufficient.

[0033] The bidirectional controllable DC source monitoring module with resistance and inductance parameter detection includes an EMI filter, an auxiliary power supply 1, an auxiliary power supply 2, a core control unit 1, a core control unit 2, a display and control unit, and a resistance and inductance parameter detection unit.

[0034] The EMI filter and the three-phase AC input monitoring module are first filtered by the EMI filter to remove the interference of the high-frequency pulses of the power grid on the power supply, while reducing the electromagnetic interference of the power supply itself on the input power grid.

[0035] The auxiliary power supply 1 and the auxiliary power supply 2, and the EMI filter output power are sent to the auxiliary power supply 1 and the auxiliary power supply 2. The auxiliary power supply 1 and the auxiliary power supply 2 convert the filtered three-phase AC 380V into DC 24V, and respectively power the core control unit 1 and the core control unit 2.

[0036] Core Control Units 1 and 2 are responsible for monitoring and grouping power modules. They communicate externally via Ethernet or CAN bus to obtain control device power on / off and output current commands, and provide feedback on the operating status of the bidirectionally controllable DC power supply. Internally, they communicate via RS485 to exchange data with the display and control unit and the resistance-inductance parameter detection unit. The two core control units function identically, with Core Control Unit 2 serving as a redundant backup for Core Control Unit 1. If Core Control Unit 1 fails, Core Control Unit 2 becomes operational.

[0037] The display and control unit includes a liquid crystal display and key control, which can realize the human-computer interaction interface display and panel key response, and communicate with the core control unit and the resistance-sensing parameter detection unit through the internal RS485 bus.

[0038] The flow chart displayed on the human-computer interaction interface is as follows: Figure 2 As shown, the main display is divided into two main sections: status display and function settings. The "OK" and "Return" buttons allow you to view the detailed status of each power module on the main display. You can also switch between the "Set" and "Return" buttons and the function settings interface. In the function settings interface, press "1" to test the resistance and inductance parameters, press "2" to configure each power module, press "3" for manual control, and enable free combination and branch output of each power module. Press "4" to display all fault information. From any interface, press "Home" to return to the main display. The functions of the panel buttons are described in the table below.

[0039] Serial number button Function Description 1 0~9 number keys Enter a number in the input box 2 decimal point Enter decimal point 3 "” Use when entering a negative number 4 "Direction keys" Controls to move the selected box 5 Sure Enter OK 6 set up Go to the function selection menu 7 Home Return to the status display home page 8 Cancel Cancel input or return to the previous menu

[0040] The resistance-inductance parameter detection unit is used to detect the size of the load inductance and resistance. According to the received instructions, it controls the load relay at the output end of the power module outside the monitoring module, performs resistance-inductance parameter detection on the load in turn, and transmits the detection value back to the core control unit and the display and control unit through internal RS485 communication.

[0041] Figure 3 The following figure shows the functional block diagram of the resistance-inductance parameter detection unit. The monitoring module is equipped with a 380V / 20V transformer as an excitation source. Upon receiving a resistance-inductance parameter detection command, the monitoring module shuts down all power modules except those in the resistance-inductance parameter detection unit. It then connects the excitation source to the resistance-inductance load 1 by closing relays KL1-1 and KL1-2, which are connected in series across the resistance-inductance load 1. A 50Hz excitation voltage is applied to the resistance-inductance load 1, while the voltage and current across the load are simultaneously detected and transformed using a Fast Fourier Transform (FFT) to obtain the voltage and current amplitude and phase information. This calculation then determines the inductance L1 and resistance R1 of the resistance-inductance load 1.

[0042] Assume that the signal of the excitation source is f(t) = A0 cos(100πt+θ), A0 is the amplitude of the excitation source, and θ is the phase of the excitation source; taking 4 points sampled in one cycle as an example, the sampling time t is 1 / 200 second, then the wave series sampled under the action of the excitation source signal is x[0] = A cos(θ), x[1] = A cos(π / 2+θ), x[2] = A cos(π+θ), x[3] = A cos(3π / 2+θ), and A is the amplitude of the sampled wave.

[0043] Perform Fourier transform on the collected waveform under the action of the excitation source signal to obtain:

[0044] N is the number of sampling points in a cycle.

[0045] Only the fundamental content of K=1 is calculated as:

[0046]

[0047] Then the amplitude and phase of voltage and current are:

[0048] U(1)=2AU[cos(θ)U+j sin(θ)U]=R e (U)+jL m (U) (1)

[0049] I(1)=2AI[cos(θ)I+j sin(θ)I]=R e (I)+jL m (I) (2)

[0050] U(1) / I(1)=R+j2πfL (3)

[0051] Substitute equation (1) and equation (2) into equation (3) to obtain:

[0052]

[0053] Then the resistance value of the load can be obtained as:

[0054]

[0055] The inductance value of the load is:

[0056]

[0057] In order to improve the accuracy, more sampling points in a cycle can be calculated.

[0058] Similarly, the inductance and resistance of the resistance-inductance load 2 can be detected by closing the relays KL2-1 and KL2-2, and the inductance and resistance of the resistance-inductance load 3 can be detected by closing the relays KL3-1 and KL3-2. The relays should be closed in sequence for measurement.

[0059] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A bidirectional controllable DC source monitoring module with resistance and inductance parameter detection, characterized in that: Contains EMI filter, two auxiliary power supplies, two core control units, display and control unit and resistance and inductance parameter detection unit; The EMI filter is used to filter the three-phase alternating current, remove the interference of high-frequency pulses of the power grid on the power supply, and reduce the electromagnetic interference of the power supply itself on the input power grid; The two auxiliary power supplies are used to convert the three-phase AC 380V output of the EMI filter into DC 24V to supply power to the two core control units respectively; The two core control units are redundantly designed and are used to communicate externally via Ethernet or CAN bus to obtain the on / off and output current instructions of the control device and feedback the operating status of the bidirectional controllable DC source; internally, they communicate via RS485 to exchange data with the display and control unit and the resistance and inductance parameter detection unit; The display and control unit includes a liquid crystal display and key control to realize the human-computer interaction interface display and panel key response, and communicates with the core control unit and the resistance-sensing parameter detection unit through the internal RS485 bus; The resistance-inductance parameter detection unit is used to detect the load inductance and resistance. According to the received instructions, it controls the load relay at the output end of the external power module of the monitoring module to perform resistance-inductance parameter detection on the load in turn, and transmits the detection value back to the core control unit and the display and control unit through internal RS485 communication; The resistance-inductive parameter detection unit is internally configured with a 380V / 20V transformer as an excitation source. Upon receiving a resistance-inductive parameter detection instruction, it turns off all power supplies other than the resistance-inductive parameter detection unit, closes a relay connected in series at both ends of the resistance-inductive load, connects the excitation source to the resistance-inductive load to be tested, and calculates the inductance and resistance of the resistance-inductive load. The details are as follows: Assume that the excitation source signal is , A 0 is the amplitude of the excitation source, θ is the phase of the excitation source; taking 4 points sampled in one cycle as an example, the sampling time t is 1 / 200 second, then the wave series sampled under the action of the excitation source signal is 、 、 、 , A is the amplitude of the collected wave; Perform Fourier transform on the collected waveform under the action of the excitation source signal to obtain: , N is the number of sampling points in one cycle; Only calculate K =1 is: Then the amplitude and phase of voltage and current are: (1) (2) (3) Substituting equations (1) and (2) into equation (3), we get: Then the resistance value of the load is: The inductance of the load is: 。 2. A system with a bidirectional controllable DC source monitoring module with resistance and inductance parameter detection, characterized in that: The interface between the bidirectional controllable DC source monitoring module with resistance-inductance parameter detection and the power module of claim 1 is a dual-redundant CAN interface. The bidirectional controllable DC source monitoring module with resistance-inductance parameter detection controls multiple power modules in groups according to ID identifiers, and simultaneously utilizes the real-time nature of the CAN network to perform current sharing control on the output currents of all grouped power modules. When the bidirectional controllable DC source monitoring module with resistance-inductance parameter detection detects a power module failure through the CAN network, the faulty module is promptly removed from the group, and the output currents of other power modules in the group are changed to keep the parallel output current unchanged. The bidirectional controllable DC source monitoring module with resistance-inductance parameter detection automatically limits the output current to not exceed the rated value of a single power module, so as to ensure the safety of the equipment when the number of remaining power modules in the group is insufficient.

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