A method, system, device, and storage medium for controlling the operation of a power module.
By detecting the module capacitor voltage and generating trigger pulses to control the module capacitor to operate at reduced voltage, the high failure rate problem of power module failure in modular multilevel converters is solved, and the utilization rate of power devices is improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- RONGXIN HUIKO ELECTRIC TECH CO LTD
- Filing Date
- 2023-12-29
- Publication Date
- 2026-06-30
AI Technical Summary
In modular multilevel converters, power module failures can only be handled by bypass, resulting in a high failure rate and reduced utilization of other power devices.
By detecting the module capacitor voltage, it is determined whether it exceeds the preset threshold, and a voltage reduction process is performed. Trigger pulses are generated based on the topology and converter branch current to control the module capacitor voltage to operate at reduced voltage, ensuring the safety of non-faulty power devices.
It reduces the failure rate of power modules, improves the utilization rate of power devices, and avoids resource waste caused by bypass processing.
Smart Images
Figure CN117559786B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power electronics technology, and in particular to a power module operation control method, system, device, and storage medium. Background Technology
[0002] In the field of power technology, modular multilevel converters have been widely used in power conversion applications such as flexible DC transmission, low-frequency transmission, and reactive power compensation. The power devices constituting the sub-modules are diverse, with commonly used power devices including IGBTs, IEGTs, and IGCTs. Although the withstand voltage ratings of these power devices have increased with continuous device updates and optimizations, a qualitative leap in withstand voltage ratings has not yet been achieved.
[0003] With increasingly higher voltage levels required for flexible DC transmission, low-frequency transmission, and reactive power compensation, modular multilevel converters incorporate more and more power modules. Simultaneously, higher voltage and higher power modules have been developed, exemplified by power modules composed of multiple power devices connected in series. These modules operate at voltages many times higher than conventional power modules, enabling high-voltage, high-power operation. While power modules composed of power devices connected in series can achieve higher voltage and higher power, their failure rate remains consistently high due to the multiple devices being connected in series.
[0004] Currently, when a power device in a power module fails, the only solution is to bypass the faulty power module and prevent it from operating the modular multilevel converter. In a modular multilevel converter, the failure of a single power device causes the entire power module to shut down, which not only fails to reduce the failure rate of the power module but also reduces the utilization rate of other power devices within that module. Summary of the Invention
[0005] To address the aforementioned technical problems, this invention provides a power module operation control method, system, device, and storage medium to enable operation of the power module under fault conditions, thereby reducing the failure rate of the power module and improving the utilization rate of power devices in the power module.
[0006] In a first aspect, embodiments of the present invention provide a power module operation control method, applied to a power module operation control system for controlling a power module, wherein the power module includes a plurality of power devices, a bypass switch, and a module capacitor, and the method includes:
[0007] Obtain the topology of the power module and the converter branch current;
[0008] Detect fault information of power devices in the power module and parse the fault information;
[0009] When the power devices in the power module are not faulty, the first capacitor voltage of the module capacitor is obtained; the rated voltage of the module capacitor in the power module is used as a reference value, and the capacitor voltage of the module capacitor is calibrated per unit. The obtained first per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse.
[0010] When a power device in the power module fails, the second capacitor voltage of the module capacitor is obtained;
[0011] Determine whether the voltage of the second capacitor exceeds a preset threshold;
[0012] When the voltage of the second capacitor exceeds a preset threshold, the voltage of the module capacitor is reduced according to the topology of the power module and the converter branch current to obtain a second trigger pulse;
[0013] When the voltage of the second capacitor does not exceed the preset threshold, the second rated voltage of the module capacitor in the power module is used as the reference value, the capacitor voltage of the module capacitor is calibrated per unit, and the obtained second per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the third trigger pulse.
[0014] Based on the fault information of the power device and the capacitor voltage of the module capacitor, a corresponding trigger pulse is output.
[0015] In some embodiments, when the power devices in the power module are not faulty, the first capacitor voltage of the module capacitor is obtained; the rated voltage of the module capacitor in the power module is used as a reference value, the capacitor voltage of the module capacitor is scaled per unit, and the obtained first per-unit value is processed by the converter branch nearest-level approximation modulation algorithm to obtain a first trigger pulse, including:
[0016] When the power devices in the power module are not faulty, the rated voltage of the module capacitor in the power module is used as the reference value U. cn The first capacitor voltage U of the module capacitor c Perform per-unit marking and obtain the first per-unit value u. c * ;
[0017]
[0018] The first trigger pulse is obtained by sorting the converter branch using the first per-unit value uc* using the nearest level approximation modulation algorithm.
[0019] In some embodiments, the topology of the power module includes:
[0020] Half-bridge topology and full-bridge topology.
[0021] In some embodiments, when the power module's topology is a half-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module's topology and the converter branch current to obtain a second trigger pulse, including:
[0022] The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged.
[0023] When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a first type of second trigger pulse is generated; the first type of second trigger pulse can control the shutdown of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and activate all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2 ]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology.
[0024] When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a second type of second trigger pulse is generated; the second type of second trigger pulse can control the activation of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and shut down all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2 ]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology.
[0025] When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a third type of second trigger pulse is generated; the third type of second trigger pulse can control and maintain the on / off state of the upper bridge arm T1 and the lower bridge arm T2 in the power module.
[0026] In some embodiments, when the power module's topology is a full-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module's topology and the converter branch current to obtain a second trigger pulse, including:
[0027] The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged.
[0028] When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fourth type of second trigger pulse is generated; the fourth type of second trigger pulse can control the activation of the first lower bridge arm T in the power module. 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ], shut down the first upper bridge arm T in the power module 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ];
[0029] When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fifth type of second trigger pulse is generated; the fifth type of second trigger pulse can control the activation of the first upper bridge arm T in the power module. 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ], turn off the first lower bridge arm T in the power module 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ];
[0030] When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a sixth type of second trigger pulse is generated; the sixth type of second trigger pulse can control and maintain the first upper bridge arm T in the power module. 11 First lower bridge arm T 12 Second upper bridge arm T 21 Second lower bridge arm T 22 On / off state;
[0031] Wherein, n11 is the number of power devices in the first upper arm of the power module of the full-bridge topology, n12 is the number of power devices in the first lower arm of the power module of the full-bridge topology, n21 is the number of power devices in the second upper arm of the power module of the full-bridge topology, and n22 is the number of power devices in the second lower arm of the power module of the full-bridge topology.
[0032] In some embodiments, the maximum fault-state commutation current value I swMax The maximum commutation current value required for the safe overvoltage turn-on or turn-off operation of the power devices in the power module.
[0033] In some embodiments, the second rated voltage is (Nn) of the rated voltage of the module capacitor in the power module. i ) / N times;
[0034] Where, n i N represents the number of power devices that failed on the bridge arm with the most failed power devices in each bridge arm of the power module.
[0035] Secondly, embodiments of this application provide a power module operation control system for controlling a power module, wherein the power module includes a plurality of power devices, a bypass switch, and a module capacitor, and the system includes:
[0036] The detection module is used to acquire the topology of the power module and the converter branch current; detect the fault information of the power devices in the power module and parse the fault information;
[0037] The normal operation pulse trigger module is used to obtain the first capacitor voltage of the module capacitor when the power device in the power module is not faulty; using the rated voltage of the module capacitor in the power module as a reference value, the capacitor voltage of the module capacitor is calibrated per unit; the obtained first per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse, and the first trigger pulse is sent to the trigger pulse selection module;
[0038] The fault-reducing pulse triggering module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage exceeds the preset threshold, reduce the capacitor voltage of the module capacitor according to the topology of the power module and the converter branch current, obtain a second trigger pulse, and send the second trigger pulse to the trigger pulse selection module.
[0039] A buck operation pulse trigger module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage does not exceed the preset threshold, use the second rated voltage of the module capacitor in the power module as a reference value, standardize the capacitor voltage of the module capacitor by per unit, process the obtained second per-unit value with the converter branch nearest level approximation modulation algorithm, obtain a third trigger pulse, and send the third trigger pulse to the trigger pulse selection module;
[0040] The trigger pulse selection module is used to output a corresponding trigger pulse based on the fault information of the power device and the capacitor voltage of the module capacitor.
[0041] Thirdly, embodiments of the present invention provide a power module operation control device, including: a controller and a memory; the memory is used to store instructions, and when the controller executes the instructions, it implements the power module operation control method described in the first aspect above.
[0042] Fourthly, embodiments of the present invention provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the power module operation control method described in the first aspect above.
[0043] Compared with traditional technologies, the beneficial effects of this invention are as follows: when a power module malfunctions, it detects whether the capacitor voltage of the module capacitor exceeds a preset threshold. If it exceeds the preset threshold, a second trigger pulse is used to reduce the voltage of the module capacitor. When the voltage drops below the preset threshold, a third trigger pulse is used to control the power module to operate at reduced voltage. The above method performs reduced voltage operation when a power device in the power module malfunctions, solving the problem that in traditional technologies, a bypass operation is the only option when a malfunction occurs. This improves the utilization rate of other power devices in the power module, thereby further reducing the failure rate of the power module.
[0044] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.
[0045] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0046] Figure 1 This is a flowchart illustrating the power module operation control method provided by the present invention;
[0047] Figure 2 This is a schematic diagram of the power module operation control system provided by the present invention;
[0048] Figure 3 A schematic diagram of a power module structure with a half-bridge topology, which is provided by the power module operation control method of the present invention;
[0049] Figure 4 A schematic diagram of a power module structure with a full-bridge topology, which is provided by the power module operation control method of the present invention;
[0050] Figure 5 This is a circuit diagram of a multilevel converter provided by the present invention;
[0051] Figure 6 This is a schematic diagram of the converter branch control section provided by the present invention. Detailed Implementation
[0052] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0053] Example 1:
[0054] This invention provides a power module operation control method, referencing... Figure 1 A power module operation control method is applied to a power module operation control system for controlling a power module, wherein the power module includes several power devices, a bypass switch, and a module capacitor, and the method includes:
[0055] S101. Obtain the topology of the power module and the converter branch current;
[0056] S102. Detect the fault information of the power devices in the power module and parse the fault information;
[0057] S103. When the power devices in the power module are not faulty, obtain the first capacitor voltage of the module capacitor; use the rated voltage of the module capacitor in the power module as a reference value, standardize the capacitor voltage of the module capacitor by per unit, and process the obtained first per-unit value using the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse.
[0058] S104. When a power device in the power module fails, the second capacitor voltage of the module capacitor is obtained.
[0059] S105. Determine whether the voltage of the second capacitor exceeds a preset threshold.
[0060] S106. When the voltage of the second capacitor exceeds a preset threshold, the voltage of the module capacitor is reduced according to the topology of the power module and the converter branch current to obtain a second trigger pulse.
[0061] S107. When the voltage of the second capacitor does not exceed the preset threshold, the second rated voltage of the module capacitor in the power module is used as the reference value, the capacitor voltage of the module capacitor is calibrated per unit, and the obtained second per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the third trigger pulse.
[0062] S108. Based on the fault information of the power device and the capacitor voltage of the module capacitor, output the corresponding trigger pulse.
[0063] Based on the fault information of the power device and the capacitor voltage of the module capacitor, select the corresponding first trigger pulse, second trigger pulse or third trigger pulse to output.
[0064] The working principle of the above power module operation control method is as follows: the power module operates normally and participates in the nearest-level approximation modulation of the converter branch through the signal emitted by the first trigger pulse. When a power device in the power module fails, the capacitor voltage of the module capacitor is detected. When the capacitor voltage exceeds a preset threshold, the voltage of the module capacitor is reduced through the signal emitted by the second trigger pulse. During the voltage reduction, the module no longer participates in the nearest-level approximation modulation of the converter branch. When the capacitor voltage does not exceed the preset threshold, or when the voltage of the module capacitor is reduced to below the preset threshold, the power module is controlled to operate at reduced voltage and participate in the nearest-level approximation modulation of the converter branch through the signal emitted by the third trigger pulse.
[0065] The beneficial effects of the above-mentioned power module operation control method are as follows: when the power module is not faulty, it operates normally via the first trigger pulse; when a fault occurs, it detects whether the voltage of the module capacitor exceeds a preset threshold. If the voltage exceeds the preset threshold, it reduces the voltage of the module capacitor via the second trigger pulse. When the voltage drops below the preset threshold, it controls the power module to operate at reduced voltage via the third trigger pulse. Compared with traditional technology, the above method performs reduced voltage operation when a power device in the power module fails, solving the problem that traditional technology can only operate via bypass when a fault occurs. This improves the utilization rate of other power devices in the power module, thereby further reducing the failure rate of the power module operation.
[0066] Example 2:
[0067] This invention provides a power module operation control method. In some embodiments, when the power devices in the power module are not faulty, the method involves obtaining a first capacitor voltage of the module capacitor; using the rated voltage of the module capacitor as a reference value, scaling the capacitor voltage to per unit value; and applying the obtained first per-unit value to a converter branch nearest-level approximation modulation algorithm to obtain a first trigger pulse. The method includes:
[0068] When the power devices in the power module are not faulty, the rated voltage of the module capacitor in the power module is used as the reference value U. cn The first capacitor voltage U of the module capacitor c Perform per-unit marking and obtain the first per-unit value u. c * ;
[0069]
[0070] The first trigger pulse is obtained by sorting the converter branch using the first per-unit value uc* using the nearest level approximation modulation algorithm.
[0071] The nearest-level-approximation modulation algorithm sorts the per-unit values of the capacitor voltages of each power module according to the flow direction of the converter branch current in the power module, and obtains the first trigger pulse based on the nearest-level-approximation modulation algorithm.
[0072] In the above embodiments, when no fault is detected in the power devices, the rated voltage of the power module is used as a reference value to standardize the per-unit voltage of the module capacitors, obtaining a first per-unit value, which is then sent to the converter branch nearest-level approximation algorithm for processing. The converter branch nearest-level approximation algorithm sorts the per-unit values of the capacitor voltages of each power module according to the charging and discharging status of the capacitors in the power modules based on the branch current, and outputs a first trigger pulse based on the nearest-level approximation modulation algorithm. This ensures that power modules that have not experienced a fault can participate normally in the modulation of the converter branch.
[0073] In the above embodiments, the first trigger pulse is used to transmit to the power module to achieve the above operation when the power device is detected to be fault-free.
[0074] Example 3:
[0075] This invention provides a power module operation control method, in which the power module topology includes a half-bridge topology and a full-bridge topology.
[0076] In the above embodiments, the power module with a half-bridge topology is as follows: Figure 3 As shown, the power module of the full-bridge topology is as follows: Figure 4 As shown, the module capacitor is C, and the bypass switch is K.
[0077] Example 4:
[0078] This invention provides a power module operation control method. When the power module's topology is a half-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module's topology and the converter branch current to obtain a second trigger pulse, including:
[0079] The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged.
[0080] When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a first type of second trigger pulse is generated; the first type of second trigger pulse can control the shutdown of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and activate all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology.
[0081] When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a second type of second trigger pulse is generated; the second type of second trigger pulse can control the activation of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and shut down all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2 ]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology.
[0082] When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a third type of second trigger pulse is generated; the third type of second trigger pulse can control and maintain the on / off state of the upper bridge arm T1 and the lower bridge arm T2 in the power module.
[0083] In the above embodiments, when the power module topology is a half-bridge topology, the current value I of the converter branch current is analyzed. ba The upper bridge arm T1 and lower bridge arm T2 in the power module are switched on and off to reduce the voltage of the module capacitor. At the same time, since the switching action of the power device is completed when the current is small, the safety of the remaining non-faulty power devices can still be guaranteed even though the capacitor voltage is high at this time.
[0084] In the above embodiments, the second trigger pulse is used to transmit the second trigger pulse to the power module of the half-bridge topology when a power device failure is detected and the capacitor voltage of the module capacitor exceeds a preset threshold, so as to achieve the above operation.
[0085] In the above embodiments, several power devices are connected in series on the upper and lower bridge arms of the power module.
[0086] In one specific embodiment, the power device may be implemented as a press-fit IGBT (Insulated Gate Bipolar Transistor), IEGT (Injection Enhancement Gate Transistor), and IGCT (Insulated Gate Controlled Bipolar Thyristor).
[0087] Example 5:
[0088] This invention provides a power module operation control method. When the power module has a full-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module topology and the converter branch current to obtain a second trigger pulse, including:
[0089] The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged.
[0090] When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fourth type of second trigger pulse is generated; the fourth type of second trigger pulse can control the activation of the first lower bridge arm T in the power module. 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ], shut down the first upper bridge arm T in the power module 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ];
[0091] When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fifth type of second trigger pulse is generated; the fifth type of second trigger pulse can control the activation of the first upper bridge arm T in the power module. 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ], turn off the first lower bridge arm T in the power module 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ];
[0092] When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a sixth type of second trigger pulse is generated; the sixth type of second trigger pulse can control and maintain the first upper bridge arm T in the power module. 11 First lower bridge arm T 12 Second upper bridge arm T 21 Second lower bridge arm T 22 On / off state;
[0093] Wherein, n11 is the number of power devices in the first upper arm of the power module of the full-bridge topology, n12 is the number of power devices in the first lower arm of the power module of the full-bridge topology, n21 is the number of power devices in the second upper arm of the power module of the full-bridge topology, and n22 is the number of power devices in the second lower arm of the power module of the full-bridge topology.
[0094] In some embodiments, the maximum fault-state commutation current value I swMax The maximum commutation current value required for the safe overvoltage turn-on or turn-off operation of the power devices in the power module.
[0095] In some embodiments, the second rated voltage is (Nn) of the rated voltage of the module capacitor in the power module. i ) / N times;
[0096] Where, n i N represents the number of power devices that failed on the bridge arm with the most failed power devices in each bridge arm of the power module.
[0097] In the above embodiments, when the power module topology is a full-bridge topology, the current value I of the converter branch current is analyzed. ba For the first upper bridge arm T in the power module 11 First lower bridge arm T 12 Second upper bridge arm T 21 Second lower bridge arm T 22 On / off control is implemented to reduce the voltage of the module capacitors. Simultaneously, because the switching actions of the power devices are completed when the current is low, even though the capacitor voltage is high at this time, the safety of the remaining non-faulty power devices can still be guaranteed.
[0098] In the above embodiments, the second trigger pulse is used to transmit the second trigger pulse to the power module of the full-bridge topology when a power device failure is detected and the capacitor voltage of the module capacitor exceeds a preset threshold, so as to achieve the above operation.
[0099] In the above embodiments, several power devices are connected in series on the first upper bridge arm, the first lower bridge arm, the second upper bridge arm, and the second lower bridge arm of the power module.
[0100] In the above embodiments, when a power device in the power module fails, the remaining unfailed power devices on the same bridge arm will experience a higher voltage. If the capacitor voltage of the power module is directly reduced by near-nearest-level approximation modulation, it is highly likely that the power devices in the power module will undergo overvoltage switching operations under high current conditions, leading to damage to the remaining power devices. Therefore, the above technical solution limits the commutation current during the switching operations of the power devices before the capacitor voltage of the power module drops to a safe range, thereby protecting other unfailed power devices.
[0101] Example 6:
[0102] This invention provides a power module operation control method, wherein the maximum commutation current value I in the fault state is... swMax The maximum commutation current value required for safe overvoltage turn-on or turn-off operations of power devices in the power module.
[0103] In the above embodiments, when a power device in the power module fails, by setting the maximum commutation current value in the fault state, it is ensured that other power devices that have not failed will not be damaged by the overvoltage and high current switch when they are turned on and off, thereby reducing the failure rate of the power module.
[0104] Example 7:
[0105] This invention provides a power module operation control method, wherein the second rated voltage is (Nn) of the rated voltage of the power module. i ) / N times;
[0106] Where, n i N represents the number of power devices that failed in the bridge arm with the most failed power devices in each bridge arm of the power module.
[0107] In the above embodiments, the second rated voltage is (Nn) of the rated voltage of the power module. i ) / N times.
[0108] In one embodiment, when the power module has a half-bridge topology, the number of power devices that fail in the upper bridge arm T1 and the lower bridge arm T2 are counted respectively. When the number of power devices that fail in the upper bridge arm T1 is greater than the number of power devices that fail in the lower bridge arm T2, the second rated voltage is (N-n1) / N times the rated voltage of the power module, where n1 is the number of power devices that fail in the upper bridge arm T1 and N is the number of power devices in the upper bridge arm T1.
[0109] In one embodiment, when the power module has a half-bridge topology, N can be either N1 or N2.
[0110] In one embodiment, when the power module's topology is a full-bridge topology, N can take the value N. 11 N 12 N 21 or N 22 .
[0111] In one embodiment, when a power device fault is detected and the capacitor voltage of the module capacitor does not exceed a preset threshold, the second rated voltage of the module capacitor in the power module is used as a reference value to standardize the capacitor voltage of the module capacitor in per unit, obtain the second per-unit value, and perform converter branch nearest-level approximation modulation algorithm processing; the converter branch nearest-level approximation modulation algorithm sorts the per-unit values of the capacitor voltage of each power module according to the charging and discharging status of the power module capacitor by the branch current, and outputs a third trigger pulse based on the nearest-level approximation modulation algorithm.
[0112] Example 8:
[0113] like Figure 2 As shown in the figure, this application provides a power module operation control system for controlling a power module. The power module includes several power devices, a bypass switch, and a module capacitor. The system includes:
[0114] The detection module is used to acquire the topology of the power module and the converter branch current; detect the fault information of the power devices in the power module and parse the fault information;
[0115] The normal operation pulse trigger module is used to obtain the first capacitor voltage of the module capacitor when the power device in the power module is not faulty; using the rated voltage of the module capacitor in the power module as a reference value, the capacitor voltage of the module capacitor is calibrated per unit; the obtained first per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse, and the first trigger pulse is sent to the trigger pulse selection module;
[0116] The fault-reducing pulse triggering module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage exceeds the preset threshold, reduce the capacitor voltage of the module capacitor according to the topology of the power module and the converter branch current, obtain a second trigger pulse, and send the second trigger pulse to the trigger pulse selection module.
[0117] A buck operation pulse trigger module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage does not exceed the preset threshold, use the second rated voltage of the module capacitor in the power module as a reference value, standardize the capacitor voltage of the module capacitor by per unit, process the obtained second per-unit value with the converter branch nearest level approximation modulation algorithm, obtain a third trigger pulse, and send the third trigger pulse to the trigger pulse selection module;
[0118] The trigger pulse selection module is used to output a corresponding trigger pulse based on the fault information of the power device and the capacitor voltage of the module capacitor.
[0119] In the above embodiments, when the detection module detects that the power device in the power module has not failed, the trigger pulse selection module transmits a first trigger pulse to the power module through the normal operation pulse trigger module. The first trigger pulse uses the rated voltage of the power module as a reference value to standardize the voltage of the module capacitor in per unit, and sends the obtained first per unit value to the converter branch nearest level approximation modulation algorithm for processing.
[0120] In the above embodiments, when the detection module detects a fault in the power device and the capacitor voltage of the module capacitor exceeds a preset threshold, the trigger pulse selection module outputs a second trigger pulse to the power module through the fault step-down pulse trigger module. The second trigger pulse is obtained by stepping down the voltage of the module capacitor according to the topology of the power module and the converter branch current.
[0121] In the above embodiments, when the detection module detects a fault in the power device and the capacitor voltage of the module capacitor does not exceed a preset threshold, the trigger pulse selection module outputs a third trigger pulse to the power module through the step-down operation pulse trigger module. The third trigger pulse uses the second voltage of the power module as a reference value to standardize the voltage of the module capacitor by per unit, and processes the obtained second per-unit value using the converter branch nearest level approximation modulation algorithm.
[0122] The working principle of the power module fault operation system for power devices in series described above is as follows: the trigger pulse selection module controls the power module to operate normally and participate in the nearest level approximation modulation of the converter branch through the first trigger pulse issued by the normal operation pulse trigger module; when the detection module detects a fault in the power device in the power module and the voltage of the module capacitor exceeds a preset threshold, it controls the voltage of the module capacitor to be reduced through the second trigger pulse issued by the fault reduction pulse trigger module, and no longer participates in the nearest level approximation modulation algorithm during the reduction period; when the capacitor voltage does not exceed the preset threshold, or the voltage of the module capacitor is reduced to below the preset threshold, the power module is controlled to operate at reduced voltage and participate in the nearest level approximation modulation of the converter branch through the third trigger pulse issued by the reduction operation pulse trigger module.
[0123] The beneficial effects of the above-mentioned power module fault operation system for power devices in series are as follows: when the power module is not faulty, it operates normally via the first trigger pulse; when a fault occurs, it detects whether the voltage of the module capacitor exceeds a preset threshold. If the voltage exceeds the preset threshold, it reduces the voltage of the module capacitor via the second trigger pulse. When the voltage drops below the preset threshold, it controls the power module to operate at reduced voltage via the third trigger pulse. Compared with traditional technology, the above system performs reduced voltage operation when a power device in the power module fails, solving the problem that traditional technology can only operate via bypass when a fault occurs. This improves the utilization rate of other power devices in the power module, thereby further reducing the failure rate of the power module.
[0124] Example 9:
[0125] A power module operation control device includes a controller and a memory; the memory is used to store instructions, and when the controller executes the instructions, it implements the power module operation control method described in any of the above embodiments.
[0126] In the above embodiments, the controller executes the instructions in the memory and outputs the corresponding trigger pulses to realize the step-down operation of the power module when the power device fails, thereby reducing the failure rate of the power module.
[0127] It should be noted that the power module operation control method provided in this application embodiment is generally applied to multilevel converters, such as... Figure 5 The diagram shown is a circuit schematic of a multilevel converter provided in an embodiment of this application. Figure 5 As can be seen in a converter branch (e.g.) Figure 5 On the CU branch (i.e., the C branch and UP bridge branch of the multilevel converter), multiple power modules are connected in series. These modules can all be half-bridge power modules, all be full-bridge power modules, or both half-bridge and full-bridge power modules can be present at the same time.
[0128] like Figure 6 The diagram shown is a schematic of the converter branch control section provided in an embodiment of this application. Figure 6 Taking one converter branch, we can see that there are M power modules. Taking the first power module 1# as an example, the capacitor voltage of the module capacitor in the power module is collected, and then the control unit of module 1# is calibrated per unit. Then, the per-unit value of the capacitor voltage is used to participate in the nearest level approximation modulation algorithm to obtain the trigger pulse, which is the first trigger pulse in this application. The pulse is then returned to the control unit of module 1#. This process is the control process when the power module is fault-free. Each power module performs this control process when it is fault-free.
[0129] Furthermore, when a power module fault is detected, the module 1# control unit still collects the capacitor voltage and then determines whether the capacitor voltage exceeds a preset threshold. If it exceeds the preset threshold, the module 1# control unit no longer performs the previous step of using the per-unit value of the capacitor voltage to participate in the nearest-level approximation modulation algorithm to obtain a trigger pulse. Instead, it acquires the topology of power module 1# and the converter branch current, performs voltage reduction processing on the module capacitor of power module 1#, and obtains a second trigger pulse. The module 1# control unit sends the second trigger pulse to power module 1# to control the on / off state of the power devices in power module 1#.
[0130] During voltage drop processing, fault information and capacitor voltage are continuously collected to determine whether a fault exists and whether the capacitor voltage does not exceed a preset threshold. When it is determined that there is a faulty power device in the power module and the capacitor voltage does not exceed the preset threshold, the second rated voltage of the module capacitor in the power module is used as the reference value. The capacitor voltage of the module capacitor is calibrated per unit to obtain the second per-unit value. Then, the converter branch nearest-level approximation modulation algorithm is applied to obtain the third trigger pulse. The second rated voltage of the module capacitor is (N-n1) / N times the rated voltage of the power module, where n1 is the number of power devices that have failed on the upper bridge arm T1 and N is the number of power devices on the upper bridge arm T1. The module 1# control unit sends the third trigger pulse to the power module 1#.
[0131] Compared with traditional technologies, this control method allows the system to operate at reduced voltage when a power device in the power module fails. This solves the problem that traditional technologies can only operate via bypass when a fault occurs, improving the utilization rate of other power devices in the power module and further reducing the failure rate of the power module.
[0132] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.
[0133] The units or modules described in the embodiments of this invention can be implemented in software or hardware. The described units or modules can also be housed in a processor. The embodiments of this invention also provide a computer-readable storage medium, which can be the computer-readable storage medium included in the talent recommendation device described in the above embodiments; or it can be a standalone computer-readable storage medium not assembled into an electronic device. The computer-readable storage medium stores one or more programs, which are used by one or more processors to execute a power module operation control method described in this invention.
[0134] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.
Claims
1. A power module operation control method, characterized in that, A power module operation control system applied to a power module, wherein the power module includes several power devices, a bypass switch, and a module capacitor, and the method includes: Obtain the topology of the power module and the converter branch current; Detect fault information of power devices in the power module and parse the fault information; When the power devices in the power module are not faulty, the first capacitor voltage of the module capacitor is obtained; the rated voltage of the module capacitor in the power module is used as a reference value, and the capacitor voltage of the module capacitor is calibrated per unit. The obtained first per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse. When a power device in the power module fails, the second capacitor voltage of the module capacitor is obtained; Determine whether the voltage of the second capacitor exceeds a preset threshold; When the voltage of the second capacitor exceeds a preset threshold, the voltage of the module capacitor is reduced according to the topology of the power module and the converter branch current to obtain a second trigger pulse; When the voltage of the second capacitor does not exceed the preset threshold, the second rated voltage of the module capacitor in the power module is used as the reference value, the capacitor voltage of the module capacitor is calibrated per unit, and the obtained second per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the third trigger pulse. Based on the fault information of the power device and the capacitor voltage of the module capacitor, a corresponding trigger pulse is output.
2. The power module operation control method according to claim 1, characterized in that, When the power devices in the power module are not faulty, the first capacitor voltage of the module capacitor is obtained; the rated voltage of the module capacitor in the power module is used as a reference value, and the capacitor voltage of the module capacitor is calibrated per unit. The obtained first calibrated per-unit value is processed by the converter branch nearest-level approximation modulation algorithm to obtain the first trigger pulse, including: When the power devices in the power module are not faulty, the rated voltage of the module capacitor in the power module is used as the reference value U. cn The first capacitor voltage U of the module capacitor c Perform per-unit marking and obtain the first per-unit value u. c * ; The first trigger pulse is obtained by sorting the converter branch using the first per-unit value uc* using the nearest level approximation modulation algorithm.
3. The power module operation control method according to claim 1, characterized in that, The topology of the power module includes: Half-bridge topology and full-bridge topology.
4. The power module operation control method according to claim 3, characterized in that, When the power module's topology is a half-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module's topology and the converter branch current to obtain a second trigger pulse, including: The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged. When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a first type of second trigger pulse is generated; the first type of second trigger pulse can control the shutdown of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and activate all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2 ]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology. When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a second type of second trigger pulse is generated; the second type of second trigger pulse can control the activation of all power devices in the upper bridge arm T1 of the power module [T 1,1 ,…,T 1,n1 [T] and shut down all power devices in the lower bridge arm T2 of the power module. 2,1 ,…,T 2,n2 ]; where n1 is the number of power devices in the upper arm of the power module of the half-bridge topology, and n2 is the number of power devices in the lower arm of the power module of the half-bridge topology. When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a third type of second trigger pulse is generated; the third type of second trigger pulse can control and maintain the on / off state of the upper bridge arm T1 and the lower bridge arm T2 in the power module.
5. The power module operation control method according to claim 4, characterized in that, When the power module's topology is a full-bridge topology, when the second capacitor voltage exceeds a preset threshold, the capacitor voltage of the module capacitor is stepped down according to the power module's topology and the converter branch current to obtain a second trigger pulse, including: The converter branch current of the power module is collected at preset time intervals and the current values are compared and judged. When the current value I of the converter branch current ba The value is positive, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fourth type of second trigger pulse is generated; the fourth type of second trigger pulse can control the activation of the first lower bridge arm T in the power module. 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ], shut down the first upper bridge arm T in the power module 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ]; When the current value I of the converter branch current ba The value is negative, and the current value I of the converter branch current is... ba The absolute value is less than the maximum commutation current value I under fault conditions. swMax At that time, a fifth type of second trigger pulse is generated; the fifth type of second trigger pulse can control the activation of the first upper bridge arm T in the power module. 11 All power devices [T 11,1 ,…,T 11,n11 ] and the second lower bridge arm T 22 All power devices [T 22,1 ,…,T 22,n22 ], turn off the first lower bridge arm T in the power module 12 All power devices [T 12,1 ,…,T 12,n12 ] and the second upper bridge arm T 21 All power devices [T 21,1 ,…,T 21,n21 ]; When the current value I of the converter branch current ba The absolute value is greater than the maximum commutation current value I under fault conditions. swMax At that time, a sixth type of second trigger pulse is generated; the sixth type of second trigger pulse can control and maintain the first upper bridge arm T in the power module. 11 First lower bridge arm T 12 Second upper bridge arm T 21 Second lower bridge arm T 22 On / off state; Wherein, n11 is the number of power devices in the first upper arm of the power module of the full-bridge topology, n12 is the number of power devices in the first lower arm of the power module of the full-bridge topology, n21 is the number of power devices in the second upper arm of the power module of the full-bridge topology, and n22 is the number of power devices in the second lower arm of the power module of the full-bridge topology.
6. The power module operation control method according to claim 5, characterized in that, The maximum commutation current value under fault conditions I swMax The maximum commutation current value required for the safe overvoltage turn-on or turn-off operation of the power devices in the power module.
7. The power module operation control method according to claim 1, characterized in that, The second rated voltage is (Nn) of the rated voltage of the module capacitor in the power module. i ) / N times; Where, n i N represents the number of power devices that failed on the bridge arm with the most failed power devices in each bridge arm of the power module.
8. A power module operation control system, characterized in that, For controlling a power module, the power module including several power devices, a bypass switch, and a module capacitor, the system includes: The detection module is used to acquire the topology of the power module and the converter branch current; detect the fault information of the power devices in the power module and parse the fault information; The normal operation pulse trigger module is used to obtain the first capacitor voltage of the module capacitor when the power device in the power module is not faulty; using the rated voltage of the module capacitor in the power module as a reference value, the capacitor voltage of the module capacitor is calibrated per unit; the obtained first per-unit value is processed by the converter branch nearest level approximation modulation algorithm to obtain the first trigger pulse, and the first trigger pulse is sent to the trigger pulse selection module; The fault-reducing pulse triggering module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage exceeds the preset threshold, reduce the capacitor voltage of the module capacitor according to the topology of the power module and the converter branch current, obtain a second trigger pulse, and send the second trigger pulse to the trigger pulse selection module. A buck operation pulse trigger module is used to obtain the second capacitor voltage of the module capacitor when a power device in the power module fails; determine whether the second capacitor voltage exceeds a preset threshold; when the second capacitor voltage does not exceed the preset threshold, use the second rated voltage of the module capacitor in the power module as a reference value, standardize the capacitor voltage of the module capacitor by per unit, process the obtained second per-unit value with the converter branch nearest level approximation modulation algorithm, obtain a third trigger pulse, and send the third trigger pulse to the trigger pulse selection module; The trigger pulse selection module is used to output a corresponding trigger pulse based on the fault information of the power device and the capacitor voltage of the module capacitor.
9. A power module operation control device, characterized in that, include: Controller and memory; The memory is used to store instructions, which, when executed by the controller, implement the method as described in any one of claims 1-7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-7.