IGBT series valve master control and valve control device double-set redundant system

Abstract

The invention relates to an IGBT (insulated gate bipolar transistor) series valve master control and valve control device double-set redundancy system, which is characterized in that master control and valve control device double-set redundancy switching is realized under a'valve base controller-drive 'two-stage centralized control framework, when a main master control unit recognizes an internal fault, redundancy switching is performed on a master control unit, and when a main valve control unit monitors the fault, redundancy switching is performed on the master control unit; the main control unit can carry out redundancy switching on the valve control unit after a fault is informed to the main control unit, and the main control unit or the main valve control unit can carry out maintenance and replacement on the faulted valve control or main control unit without overall shutdown after the main control unit or the main valve control unit carries out redundancy switching due to the fault, so that the convenience of equipment maintenance is improved; and the shutdown of the high-voltage power electronic equipment caused by the fault of a single unit in a single set of architecture is avoided, the continuous operation of the high-voltage power electronic equipment is ensured, the reliability and stability of the power system are improved, and the continuous and stable operation of the power system is ensured.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of power electronic control, and particularly relates to a double-redundancy system of an IGBT series valve master control and valve control device. BACKGROUND

[0002] In the field of high-voltage and high-power power conversion, in order to realize high-voltage level application, a plurality of IGBT (Insulated Gate Bipolar Transistor) devices are connected in series to form a valve string, and precise voltage balancing control and synchronous control are relied on to avoid overvoltage breakdown of the devices due to voltage imbalance. In current such equipment, the valve control unit (VBC) of the IGBT series valve and the system master control unit are designed in a single set architecture, which has a significant single point failure risk. Once the single set VBC (Valve Base Controller) or the master control unit fails (such as signal interruption, control failure), the power electronic equipment will be shut down, which seriously affects the continuous and stable operation of the power system.

[0003] The traditional valve base controller adopts a three-level distributed control architecture of "valve base controller-subunit controller-driving", and the signal transmission relies on an asynchronous communication protocol. The valve control unit only issues "turn on / shut off" discrete instructions and does not transmit actual driving signals. The subunit controller has independent instruction analysis and state retention functions. After receiving the valve control instruction, the subunit controller generates the driving signal of the IGBT and sends it to the driving control IGBT to act. If the communication is interrupted, the last period driving state is automatically retained to avoid the risk of equipment caused by sudden change of the IGBT state. When the double-redundancy switching is allowed, the communication interruption window is 5-10 ms. Due to the state retention mechanism of the subunit, the IGBT driving signal in the window has no abnormal fluctuation.

[0004] The IGBT series valve base controller adopts a two-level centralized control architecture of "valve base controller-driving", and the signal transmission relies on synchronous PWM direct signal. The control and protection are all concentrated in the valve base controller. To meet the synchronous triggering and shutting down of a plurality of IGBTs, the signal transmission delay is reduced from 100-200 us to less than 1 us. The control and protection logic is changed from subunit dispersion processing to valve control unit centralized processing. The voltage balancing compensation and fault judgment of all devices need to be completed at the same time, and the control link cannot be split.

[0005] The turn-on / off timing of the series IGBTs needs to be strictly synchronized (error ≤ 60 ns), and the duty ratio and phase of the PWM wave directly determine the switching state and voltage distribution of the IGBTs. If the signal is interrupted (even for one cycle), it will cause overvoltage breakdown or short circuit of the series loop of some IGBTs. Unlike the traditional scheme of "discrete instruction fault tolerance", the PWM direct drive needs to maintain the continuity of the signal. After the traditional scheme loses the packet, the "maintain the last state" of the subunit is a safety mechanism, but if the PWM (Pulse Width Modulation) is interrupted, the "maintain the last state" will break the series voltage balancing (such as continuous conduction of some devices and shutdown of some devices), causing a chain failure. SUMMARY

[0006] In order to solve the problem that the failure of a single set of valve control unit or master control unit in the prior art will cause the shutdown of power electronic equipment and seriously affect the continuous and stable operation of the power system, the application provides an IGBT series valve master control and valve control device double-redundancy system, which comprises a double-redundancy master control unit, a double-redundancy valve control unit and a plurality of IGBT drive boards. The master control units in the double-redundancy master control unit are connected to each other, each master control unit in the double-redundancy master control unit is connected to the double-redundancy valve control unit, each valve control unit in the double-redundancy valve control unit is connected to the plurality of IGBT drive boards, the currently running master control unit and valve control unit are taken as the main master control unit and the main valve control unit respectively, and the other master control unit and valve control unit are taken as the standby master control unit and the standby valve control unit respectively. The main valve control unit is used for locking and reporting a valve control fault when an internal fault is identified when the system is in a running state. The main master control unit is used for triggering valve control switching logic, generating and issuing a valve control switching instruction when the valve control fault is received, triggering master control switching logic to generate a master control unit switching signal when an internal fault is identified, and realizing redundancy switching of the master control unit. The standby valve control unit is used for unlocking to realize redundancy switching of the valve control unit and generating a drive signal by PWM modulation according to the modulation wave signal issued by the main master control unit when the standby valve control unit is in a locked state and the valve control switching instruction is received. Each IGBT drive board is used for controlling the IGBT corresponding to each IGBT drive board according to the drive signal.

[0007] Optionally, the main master control unit is specifically configured to, when in the running state, perform self-checking by using a preset self-checking program to obtain a self-checking result, trigger a master control switching logic to generate a master control unit switching signal when the self-checking result is an internal fault, and trigger a control logic to generate and issue the modulation wave signal when the self-checking result is normal operation. The standby master control unit is specifically configured to, when in the locked state, if the master control unit switching signal is received, unlock, trigger a preset control program to generate and issue the modulation wave signal.

[0008] Optionally, the main valve control unit is specifically configured to, when in the unlocked state, perform detection by using a preset valve control self-checking program to obtain a detection result, and lock and report a valve control fault when the detection result is a valve control fault.

[0009] Optionally, each IGBT drive board is further configured to monitor the IGBT corresponding to each IGBT drive board and report an IGBT operating state and a drive board operating state. The main valve control unit is further configured to report fault information of a fault IGBT or a fault drive board when the IGBT operating state or the drive board operating state is a fault state. The main master control unit is further configured to generate an alarm signal of the fault IGBT or the fault drive board according to the fault information.

[0010] Optionally, each set of master control units in the double-set master control unit adopts a 4U chassis. The 4U chassis comprises a 4U backboard, a master control board, a DIDO board and a communication management board. The master control board, the DIDO board and the communication management board are mechanically fixed and electrically connected to the 4U backboard in a slot manner. The master control board is connected with the double-set valve control unit.

[0011] Optionally, an internal fault detection module is arranged in the master control board, and the internal fault detection module stores a preset self-checking program. The internal fault detection module is configured to detect an operating state of the main master control unit by using the preset self-checking program to determine whether the main master control unit has a fault.

[0012] Optionally, each set of valve control units in the double-set valve control unit adopts a valve control chassis. The valve control chassis comprises a backboard, a power supply board card, a master control board card and a plurality of optical transceiver board cards. The power supply board, the master control board card and the plurality of optical transceiver board cards are mechanically fixed and electrically connected to the backboard in a slot manner. The master card is connected with the double sets of master control units, and each optical transceiver card is connected with the corresponding IGBT drive board of each optical transceiver card. The power card is configured to supply power to the backplane, the master card and the plurality of optical transceiver cards. The backplane is configured to interact signals of each card. The master card is configured to generate the drive signal by using the PWM modulation based on the modulation wave signal. Each optical transceiver card is configured to send the drive signal to each IGBT drive board.

[0013] Optionally, each optical transceiver card includes a plurality of independent optical transceiver channels, and each optical transceiver channel includes a downlink channel and an uplink channel. The downlink channel and the uplink channel are connected with the corresponding IGBT drive board of each optical transceiver channel. The downlink channel is configured to send the drive signal to the corresponding IGBT drive board of each optical transceiver channel. The uplink channel is configured to receive the drive board running state of each IGBT drive board and the IGBT running state corresponding to each IGBT drive board.

[0014] Optionally, the master card includes a fault detection module. The fault detection module is configured to monitor the valve control fault of the master valve control unit and receive and send the drive board fault and the IGBT fault reported by the IGBT drive board. The master control unit is further configured to generate a fault processing signal by using a preset strategy based on the drive board fault or the IGBT fault, so as to process the fault of the IGBT drive board or the IGBT.

[0015] Optionally, each IGBT drive board includes a first optical receiving unit, a second optical receiving unit and a signal selection module. The signal selection module is connected with one end of the first optical receiving unit and one end of the second optical receiving unit. The other end of the first optical receiving unit is connected with one set of valve control units of the double sets of valve control units, and the other end of the second optical receiving unit is connected with the other set of valve control units of the double sets of valve control units.

[0016] Optionally, the signal selection module is configured to select the driving signal of the first light receiving unit when detecting that the first light receiving unit receives the driving signal, select the driving signal of the second light receiving unit when detecting that the second light receiving unit receives the driving signal, and control the corresponding IGBT of each IGBT driving board to be turned off when neither the first light receiving unit nor the second light receiving unit receives the driving signal.

[0017] Compared with the prior art, the present application has the following advantages: The application provides an IGBT series valve master control and valve control device double-set redundancy system, which realizes master control and valve control device double-set redundancy switching under a "valve base controller-driving" two-level centralized control architecture, performs redundancy switching on the master control unit when the master control unit identifies an internal fault, immediately locks the valve control unit as a whole when the master valve control unit monitors a fault, informs the master control unit of the fault, and the master control unit can perform redundancy switching on the valve control unit, and the master control unit or the master valve control unit can perform maintenance and replacement on the faulty valve control or master control without overall shutdown after redundancy switching due to faults, thereby improving the convenience of equipment maintenance, avoiding single unit failure in a single set architecture to cause high-voltage power electronic equipment to be shut down, ensuring the continuous operation of high-voltage power electronic equipment, improving the reliability and stability of the power system, and being beneficial to ensuring the continuous and stable operation of the power system. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A block diagram of an IGBT series valve master control and valve control device double-set redundancy system provided by the application is provided. Figure 2 A schematic diagram of a three-phase full-bridge topology provided by the application is provided. Figure 3 A schematic diagram of an IGBT series valve master control and valve control device double-set redundancy system architecture provided by the application is provided. Figure 4 A master control unit redundancy switching working condition logic timing diagram provided by the application is provided. Figure 5 A master control unit redundancy switching working condition logic timing diagram provided by the application is provided. Figure 6 A master control unit redundancy switching working condition logic timing diagram provided by the application is provided. Figure 7 A valve control unit redundancy switching working condition logic timing diagram provided by the application is provided. Figure 8 A valve control unit redundancy switching working condition logic timing diagram provided by the application is provided. DETAILED DESCRIPTION

[0019] Embodiment 1: Figure 1 A block diagram of an IGBT series valve master control and valve control device double set redundancy system provided by the present application is shown in FIG. 1. Figure 1 As described above, the system can include a double set of master control units, a double set of valve control units, and a plurality of IGBT drive boards. The master control units in the double set of master control units are connected to each other, each set of master control units in the double set of master control units can be connected to the double set of valve control units, each set of valve control units in the double set of valve control units is connected to the plurality of IGBT drive boards, the currently running master control unit and valve control unit are respectively used as the main master control unit and the main valve control unit, and the other set of master control unit and valve control unit are respectively used as the standby master control unit and the standby valve control unit. The main valve control unit is configured to, when the system is in a running state, if an internal fault is identified, be locked and report a valve control fault. The main master control unit is configured to, when the valve control fault is received, trigger valve control switching logic, generate and issue a valve control switching instruction, and when an internal fault is identified, trigger master control switching logic to generate a master control unit switching signal to realize redundancy switching of the master control unit. The standby valve control unit is configured to, when in a locked state, if the valve control switching instruction is received, be unlocked to realize redundancy switching of the valve control unit, and generate a drive signal by PWM modulation according to the modulation wave signal issued by the main master control unit. Each IGBT drive board is configured to control the IGBT corresponding to each IGBT drive board according to the drive signal.

[0020] As shown in FIG. 2, the IGBT series valve adopts an industrial standard three-phase full-bridge topology structure, each phase bridge arm is divided into two independent IGBT series valve strings along the current path, and the three-phase bridge arms together constitute six functionally independent IGBT series valve strings. Figure 2 As shown in FIG. 2, the IGBT series valve adopts an industrial standard three-phase full-bridge topology structure, each phase bridge arm is divided into two independent IGBT series valve strings along the current path, and the three-phase bridge arms together constitute six functionally independent IGBT series valve strings.

[0021] It should be noted that the application constructs a double-redundancy architecture suitable for IGBT series valve control and main control, and through two sets of independent and cooperative VBC and main control units, cooperation of PWM direct touch control, optical fiber transmission and other core technologies, rapid switching in a fault state is realized.

[0022] When one set of unit fails, the other set of unit can immediately take over control, and because both sets of systems adopt a non-delay precise control scheme, the ns-level synchronization accuracy and voltage uniformity of the IGBT valve string before and after switching are ensured, thereby completely solving the single-point failure problem of a single set of architecture, ensuring continuous operation of high-voltage power electronic equipment, further strengthening the overvoltage protection capability of IGBT devices, and improving the reliability and stability of the entire system.

[0023] The application is based on the characteristics of centralized optical fiber direct touch of IGBT series valve control, and aims to provide a double-redundancy system of IGBT series valve main control and valve control device, which realizes us-level fault response through multi-level redundancy design and rapid fault switching mechanism, and solves the single-point failure problem of the traditional single set of control system.

[0024] Among them, the application belongs to the reliability control technology field of series insulated gate bipolar transistors (IGBT) in high-voltage and high-power power conversion systems, and particularly relates to the technical field of double-redundancy design of series IGBT valve control unit (VBC) and system main control unit, signal interaction and fault switching.

[0025] The technology is mainly applied to series IGBT to realize high-voltage output of power electronic equipment, including but not limited to flexible AC / DC power transmission and distribution system, high-voltage frequency converter, static synchronous compensator (STATCOM), high-voltage solid-state circuit breaker and other key power system equipment, and aims to solve the system shutdown risk caused by single-point failure of series IGBT valve control and main control unit through double-redundancy architecture, and belongs to the redundancy control technical field of improving the operation stability and reliability of high-voltage power electronic equipment.

[0026] In some scenarios, a double-redundancy system of IGBT series valve main control and valve control device can also be referred to as a double-redundancy system of series IGBT valve control and main control.

[0027] For example, a double-redundancy system of series IGBT valve control and main control includes double-redundancy main control units (MCU1, MCU2), double-redundancy valve control units (VBC1, VBC2) and IGBT drive boards corresponding to IGBT devices one by one.

[0028] That is, the double main control unit can include a first main control unit MCU1 and a second main control unit MCU2, and the double valve control unit can include a first valve control unit VBC1 and a second valve control unit VBC2. The first main control unit can be in communication connection with the second main control unit, the first valve control unit and the second valve control unit, and the second main control unit can also be in communication connection with the first valve control unit and the second valve control unit. Each IGBT drive board is in communication connection with the first valve control unit and the second valve control unit. When the first main control unit and the first valve control unit are both in a running state, the first main control unit can be used as a main main control unit, the first valve control unit can be used as a main valve control unit, the second main control unit can be used as a standby main control unit, and the second valve control unit can be used as a standby valve control unit. When the second main control unit and the second valve control unit are both in a running state, the second main control unit can be used as a main main control unit, the second valve control unit can be used as a main valve control unit, the first main control unit can be used as a standby main control unit, and the first valve control unit can be used as a standby valve control unit. Generally, the standby main control unit and the standby valve control unit are in a locked state, and when a switching instruction is received, they enter an unlocked state, i.e. a running state.

[0029] The double main control unit independently runs, realizes real-time data interaction and state synchronization through optical fibers, adopts the same hardware configuration and control algorithm, can issue modulation wave signals, unlock instructions and control parameters to the double valve control unit, receive state information and fault signals uploaded by the valve control unit, and monitor the running state of the hardware and software through the built-in fault detection module. The double valve control unit is interconnected with the double main control unit, has the functions of IGBT drive signal generation, state acquisition and fault detection, and the working states are mutually exclusive. Only one set of main valve control unit is in an unlocked state and the other set of standby valve control unit is in a standby unlocked state when the system is in a normal running state. The IGBT drive board integrates a double optical receiving unit, is connected with the double valve control unit through optical fibers, and has a built-in signal selection logic to select effective drive signals. The system also has valve control switching and main control switching functions, and both types of switching meet the us-level response requirement to realize fast takeover control in a fault state or during equipment maintenance without shutdown. The double main control unit and the double valve control unit realize redundant switching through a short-time locking and unlocking strategy to complete the redundant switching of the device within 5 control cycles. The unlock and lock logic of the double main control unit is mutually exclusive, and only one set of valve control unit can be issued with an unlock instruction each time. When the double main control unit detects a fault or receives a fault signal from the main valve control unit, the switching logic of the double main control unit or the valve control switching logic can be triggered to ensure that the standby unit takes over the control quickly.

[0030] The master control redundancy switching device completes the locking from the failure to the completion of the switching and the unlocking in 5 communication cycles; the synchronization error of the on / off timing of the IGBT series connection is less than or equal to 20 ns; and the signal transmission delay between the double sets of valve control units and the driving board is less than or equal to 1 us.

[0031] Optionally, the master control unit is specifically configured to, when in the running state, perform self-checking by using a preset self-checking program to obtain a self-checking result, trigger master control switching logic to generate a master control unit switching signal when the self-checking result is an internal fault, and trigger control logic to generate and issue the modulation wave signal when the self-checking result is normal operation. The standby control unit is specifically configured to, when in the locked state, if the master control unit switching signal is received, unlock, trigger a preset control program to generate and issue the modulation wave signal.

[0032] Optionally, the control logic and the preset control program can be the same control strategy or control algorithm.

[0033] It should be noted that the master control unit, when in the running state, continuously performs self-checking by using a preset self-checking program. If it is detected that the master control unit has an internal fault, the master control switching logic is triggered to generate a master control unit switching signal, and the master control unit switching signal is sent to the standby control unit. If it is not detected that the master control unit has an internal fault, the control logic is triggered to generate a modulation wave signal, and the modulation wave signal is issued to the master valve control unit, so that the master valve control unit controls the IGBT driving board to drive the IGBT to turn on or turn off based on the modulation wave signal. Under normal circumstances, the standby control unit is in a locked state, and after receiving the master control unit switching signal, it is unlocked (i.e., enters the running state), generates a modulation wave signal, and controls the turning on or turning off of the IGBT.

[0034] For example, the master MCU (Microcontroller Unit, usually directly referred to as “single-chip microcomputer”) detects its own failure (such as CPU (Central Processing Unit) exception) → immediately locks → notifies the standby MCU through optical fiber communication → the standby MCU takes over the control after confirmation and issues an unlock instruction to the corresponding VBC.

[0035] Optionally, the master valve control unit is specifically configured to, when in the unlocked state, perform detection by using a preset valve control self-checking program to obtain a detection result, and lock and report a valve control fault when the detection result is a valve control fault.

[0036] It should be noted that the fault detection module of the double-set valve control unit can monitor three types of faults: first, its own hardware faults, including communication disconnection and frame loss faults with the main control unit, power supply faults, and optical fiber disconnection faults with all drive boards; second, faults reported by the drive boards, including overvoltage faults, short circuit faults, and drive board power supply faults; and third, overcurrent faults in current collection faults; when the main valve control unit detects a fault, it immediately performs a lockout operation and sends a fault type code to the double-set main control unit through an optical fiber, the main control unit judges that the valve control itself has a fault and performs valve control redundancy switching, and the main valve control unit becomes a standby state after being reset to recover from the fault, and needs to be repaired and then switched to a standby state when the fault cannot be recovered.

[0037] For example, the main VBC detects a fault → immediately locks and sends a fault signal to the MCU → the MCU receives the fault signal and judges that the valve control has a fault → immediately sends an unlock instruction to the standby VBC → the standby VBC unlocks and outputs a drive signal → the drive board switches to the standby signal, completing the switching.

[0038] Optionally, each IGBT drive board is further configured to monitor the corresponding IGBT of each IGBT drive board and report the running state of the IGBT and the running state of the drive board. The main valve control unit is further configured to report fault information of a fault IGBT or a fault drive board when the running state of the IGBT or the running state of the drive board is a fault state. The main control unit is further configured to generate an alarm signal of the fault IGBT or the fault drive board according to the fault information.

[0039] For example, a double-set redundant system of an IGBT series valve main control and valve control device includes a double-set main control unit, a double-set valve control unit, and an IGBT drive board, which cooperatively realize redundant control and rapid switching, and the specific structure is as follows: 1. Double-set main control unit (MCU1, MCU2) The two sets of main control units independently operate, adopt the same hardware configuration and control algorithm, and realize real-time data interaction and state synchronization through an optical fiber. Each main control unit has the following functions: The two sets of main control units independently operate, adopt the same hardware configuration and control algorithm, and realize real-time data interaction and state synchronization through an optical fiber. Each main control unit has the following functions:

[0040] Receive state information (such as valve control unlock state, valve control running mode, valve control redundancy state, etc.) and fault signals uploaded by the valve control unit.

[0041] A built-in fault detection module monitors the running state of its own hardware (such as CPU, memory, communication interface) and software in real time.

[0042] The master control unit and the valve control unit can be manually switched in normal operation of the device, meeting the needs of uninterrupted maintenance and maintenance of the system, and the standby master control unit or valve control unit can be triggered to take over the control when self-failure is detected or a failure signal of the main valve control unit is received, or the valve control switching logic is triggered, ensuring that the standby master control unit or valve control unit takes over the control quickly.

[0043] 2. Double set valve control unit (VBC1, VBC2) The two sets of valve control units are interconnected with the double set master control unit (MCU1→VBC1, MCU1→VBC2, MCU2→VBC1, MCU2→VBC2), both have IGBT drive signal generation, state acquisition and fault detection functions, and the working states are mutually exclusive. During normal operation of the system, only one set of valve control unit (main valve control) is in the unlocked state, receives the modulation wave command of the master control unit and generates the drive signal; the other set (standby valve control) is in the unlocked state, only receives the master control command but does not output the drive signal.

[0044] Each set of valve control unit has a real-time fault detection module built-in, which monitors its own hardware faults (such as communication disconnection with the master control frame fault, power failure, all optical disconnection faults with the drive board), drive board reported fault state (overvoltage, short circuit, power supply), current acquisition fault state (overcurrent).

[0045] When the main valve control detects a fault, it immediately performs a lockout operation (cuts off the IGBT drive signal) and sends a fault type code (such as VBC self-failure, drive board failure, IGBT failure, etc.) to the two sets of master control units through communication (optical fiber). The master control receives the valve control reported fault and judges whether the fault is a VBC self-failure. If it is a VBC self-failure, the master control can perform valve control redundancy switching, re-unlock the standby valve control unit, and cut off the main valve control unit. After redundancy switching, the master control resets the main valve control and detects whether the main valve control fault is cleared. If the fault is recovered, the main valve control unit is adjusted to the standby state. When the standby valve control fails, it can be switched to the main valve control again. If it cannot be recovered, it needs to be cut into the standby state after on-site maintenance.

[0046] 3. IGBT drive board Each drive board corresponds to an IGBT device, integrates a double optical receiving unit (opposite light head 1, opposite light head 2), and is connected with VBC1 and VBC2 through optical fiber to receive two independent drive optical signals; the drive board has a signal selection logic built-in, which selects the effective drive signal based on the following rules: When the light head 1 is detected to have an open communication signal, the drive board selects the light head 1 as the drive signal, which is "unlocked effective" (corresponding to the main valve control output), and selects the signal of this road to drive the IGBT.

[0047] When the optical head 2 is first detected to have the open communication signal, the drive board selects the optical head 2 as the drive signal, at this time, the main valve control is locked, the standby valve control is unlocked and outputs the drive signal, and the drive board detects the "unlock effective" signal of the standby valve control, selects the signal of the road to drive the IGBT.

[0048] Because the valve control adopts mutual exclusion unlocking logic, logically there will not be two optical heads with open communication signals at the same time. If two optical heads have open communication signals at the same time, the drive board immediately reports a fault and notifies the valve control to lock for maintenance. If both signals do not have open communication signals, the drive board keeps the IGBT off.

[0049] 4. Fault switching mechanism System fault switching includes valve control switching and main control switching, both of which meet the us-level response requirement: Valve control switching: the main VBC detects a fault → immediately locks and sends a fault signal to the MCU → after the MCU receives the fault signal, it is judged as a valve control fault (non-main control or drive board fault) → after resetting, the standby VBC is detected to be ready → the standby VBC is detected to be ready → immediately send an unlock instruction to the standby VBC → the standby VBC is unlocked and outputs the drive signal → the drive board switches to the standby signal, and the switching is completed.

[0050] Main control switching: the main MCU detects its own fault (such as receiving a control protection communication disconnection) → immediately locks → notifies the standby MCU through optical fiber communication → after the standby MCU confirms, it takes over the control and sends an unlock instruction to the corresponding VBC.

[0051] Optionally, each of the double sets of main control units adopts a 4U case; The 4U case includes a 4U backboard, a main control board, a DIDO board and a communication management board; The main control board, the DIDO board and the communication management board are mechanically fixed and electrically connected to the 4U backboard in the form of slots; The main control board is connected with the double sets of valve control units.

[0052] Among them, the main control board is provided with a built-in fault detection module, and the built-in fault detection module stores a preset self-checking program; the built-in fault detection module is used to detect the running state of the main main control unit by using the preset self-checking program to judge whether the main main control unit has a fault.

[0053] It should be noted that the double set master control unit is integrated in a 4U case, and the case includes a 4U backboard, a master control board, a DIDO board and a communication management board; the DIDO board is a digital input and output unit, responsible for trip signal output and device node state acquisition; the communication management board can realize two-way communication with the background monitoring system, upload system running data and fault information, and receive control parameter configuration instructions issued by the background.

[0054] For example, the master control unit adopts a 4U case, mainly composed of a 4U backboard, a master control board, a DIDO board and a communication management board. The 4U backboard: as a signal interaction hub, realizes high-speed signal and power interaction among the master control board, the DIDO board and the communication management board.

[0055] The master control board: the core control unit, with the following functions: generating three-phase modulation waves, and control commands (unlocking, resetting, running mode switching instructions) are sent to the valve control unit through the optical port high-speed protocol. Deploy double redundant control logic, support redundant switching of master control unit itself and downstream valve control unit, can automatically switch in case of failure, also support manual redundant switching, meet the equipment maintenance and maintenance without shutdown. Integrated fault detection module, real-time detection of the running state of the whole system, and response to the state report of other devices, can trigger local real-time trip, and respond to the trip request of the valve control unit.

[0056] The DIDO board: digital input and output unit, trip signal output and device node state acquisition.

[0057] The communication management board: realizes two-way communication with the background monitoring system, uploads system running data (such as device running mode, IGBT voltage and current) and fault information, and receives control parameter configuration instructions issued by the background.

[0058] Optionally, each valve control unit in the double set valve control unit adopts a valve control case; The valve control case includes a backboard, a power board card, a master control board card and a plurality of optical transceiver board cards; The power board, the master control board card and the plurality of optical transceiver board cards realize mechanical fixation and electrical connection with the backboard in the form of slots; The master control board card is connected with the double set master control unit, and each optical transceiver board card is connected with the corresponding IGBT drive board; The power board card is used for supplying power to the backboard, the master control board card and the plurality of optical transceiver board cards; The backboard is used for interacting signals of each board card; The master control board card is used for generating the drive signal by using the PWM modulation based on the modulation wave signal; Each optical transceiver board card is used for sending the drive signal to each IGBT drive board.

[0059] The master control board includes a fault detection module; the fault detection module is configured to monitor valve control faults of the master valve control unit, and is further configured to receive and send drive board faults and IGBT faults reported by the IGBT drive board. The master control unit is further configured to generate a fault processing signal based on the drive board fault or the IGBT fault, and to process the faults of the IGBT drive board or the IGBT by using a preset strategy.

[0060] It should be noted that the double-set valve control unit is integrated in a 6U series valve control case. The case includes four types of core boards, i.e., a backboard, a power board, a master control board, and an optical input and output board (i.e., an optical transceiver board). Each board is connected to the backboard through a standardized slot. Each optical input and output board (i.e., an optical transceiver board) integrates seven independent optical transceiver channels. One optical transceiver channel corresponds to the drive board of one IGBT. The system is configured with six optical input and output boards, and the total number of drive channels reaches 42.

[0061] For example, the core control unit (i.e., the valve control unit) of the series valve control system is integrated in a 6U series valve control case. The case includes four types of core boards, i.e., a backboard, a power board, a master control board, and an optical input and output board. Each board is connected to the backboard through a standardized slot, can be quickly disassembled and replaced, and reduces maintenance costs.

[0062] The backboard serves as the signal interaction hub of the boards in the case, and bears the functions of centralized distribution of data signals, control signals, and power supply, meeting the needs of multi-board expansion. The power board provides isolated and stable power supply for all the boards in the case. The master control board serves as the control core of the system, and can realize logical operation, fault protection, and external communication functions. The optical input and output board serves as the optical fiber interface expansion module of the master control board and the IGBT drive board, and mainly realizes bidirectional transmission of drive signal issuing and state feedback. The optical port of the optical input and output board adopts an ST type multimode optical fiber interface.

[0063] Optionally, each optical transceiver board includes multiple independent optical transceiver channels. Each optical transceiver channel includes a downlink channel and an uplink channel. The downlink channel and the uplink channel are connected to the IGBT drive board corresponding to each optical transceiver channel, respectively. The downlink channel is configured to issue the drive signal to the IGBT drive board corresponding to each optical transceiver channel. The uplink channel is configured to receive the drive board running state of each IGBT drive board and the IGBT running state corresponding to each IGBT drive board.

[0064] It should be noted that each optical input and optical output board card integrates 7 independent optical transceiver channels (i.e. 7 pairs of optical ports), and each optical transceiver channel and the driving board of one IGBT form a one-to-one corresponding connection relationship. Specifically, each channel includes a downlink channel and an uplink channel: the downlink channel is used to issue a PWM switch instruction to the driving board; the uplink channel is used to receive the IGBT running state signal fed back by the driving board. Through the design scheme of “one optical input and optical output board card corresponding to one IGBT series valve string”, the independent control and state monitoring of the 7 IGBTs in a single valve string can be realized, the signal interference between different valve strings can be effectively avoided, and the system control precision is improved.

[0065] Based on the control requirements of the six IGBT series valve strings in the three-phase full-bridge topology, six optical input and optical output board cards are configured in the system in the embodiment, and the total number of driving channels of the six board cards reaches 42 (the calculation method is 6 pieces x 7 pieces), which can completely cover the driving and monitoring requirements of the 42 IGBTs in the six valve strings.

[0066] Optionally, each IGBT driving board comprises a first optical receiving unit, a second optical receiving unit and a signal selection module. The signal selection module is connected with one end of the first optical receiving unit and one end of the second optical receiving unit respectively. The other end of the first optical receiving unit is connected with one valve control unit of the double valve control units, and the other end of the second optical receiving unit is connected with the other valve control unit of the double valve control units.

[0067] It should be noted that the driving unit (i.e. IGBT driving board) mainly realizes the triggering and turning off of IGBT, and the state detection of IGBT. Each driving unit is designed with two optical ports to communicate with two sets of valve control systems respectively, and to detect which valve control unit is used as the effective driving signal of IGBT inside. Each driving unit drives a single IGBT device.

[0068] Optionally, the signal selection module is configured to select the driving signal of the first optical receiving unit when it is detected that the first optical receiving unit receives the driving signal, select the driving signal of the second optical receiving unit when it is detected that the second optical receiving unit receives the driving signal, and control the corresponding IGBT of each IGBT driving board to turn off when neither the first optical receiving unit nor the second optical receiving unit receives the driving signal.

[0069] It should be noted that the signal selection logic of the IGB drive board satisfies: when the optical receiving unit (optical head 1, i.e. the first optical receiving unit) connected with the main valve control unit is first detected to have an open signal, the driving signal of the optical head 1 is selected; when the optical receiving unit (optical head 2, i.e. the second optical receiving unit) connected with the standby valve control unit is first detected to have an open signal, the driving signal of the optical head 2 is selected; if neither of the two signals has an open signal, the drive board keeps the IGBT off.

[0070] For example, as shown in Figure 3 The dual-redundancy system includes a first master control unit MCU1, a second master control unit MCU2, a first valve control unit VBC1, a second valve control unit VBC2, 42 drive boards, and 6 valve strings. The valve control unit includes a power supply (i.e. a power board card), a master control board card, and 6 optical input and optical output board cards. Each valve string includes 6 IGBTs.

[0071] The specific implementation steps of the redundancy switching are as follows: 1. MCU1 is the main master controller, MCU2 is the standby master controller; VBC1 is the main valve control unit, and VBC2 is the standby valve control unit; the communication link between MCU1 and VBC1 is numbered as M1-1; the communication link between MCU1 and VBC2 is numbered as M1-2; the communication link between MCU2 and VBC1 is numbered as M2-1; the communication link between MCU2 and VBC2 is numbered as M2-2; and the communication link between MCU1 and MCU2 is numbered as M1-M2. 2. After the device and system are powered on, the two sets of master controllers and the two sets of valve control units are self-checked for no faults. MCU1 issues an unlocking instruction through M1-1 and generates a modulation wave; M1-2 issues a locking instruction; and M2-1 and M2-2 remain in a locked state. 3. MCU1 and VBC1 are in a running state. VBC1 receives the unlocking instruction and the modulation wave, and generates a PWM wave to be sent to all the drive boards thereunder. 4. The drive board optical port 1 receives the PWM wave issued by VBC1. After decision-making inside the drive board, the PWM wave is issued as an IGBT driving signal to the corresponding IGBT. At this time, the device is normally unlocked and runs. The specific steps of the MCU redundancy, fault detection, and switching are as follows: 1. When MCU1 and VBC1 are in the unlocking running process, there are three working conditions for the MCU redundancy switching fault detection: 1) MCU1 works normally, the fault detection module detects a fault of itself (or manually switches during maintenance), MCU1 and MCU2 and VBC1 issue normal communication, MCU1 immediately executes device locking, informs MCU2 and VBC1 through the M1-1 and M1-M2 links, and MCU1 releases the control right. 2) VBC1 detects the failure of MCU1 M1-1 channel communication, immediately executes device locking, and reports fault information to MCU1 and MCU2 devices, MCU1 receives the fault information and releases the control right and informs MCU2 through M1-M2; 3) MCU1 works abnormally (power failure or internal hardware failure), cannot actively execute locking instructions, MCU2 takes over the control right by detecting the M1-M2 communication state between MCU1 and VBC1 and the M2-1 reporting state between VBC1.

[0072] 2. MCU2 switches from standby state to active state, takes over the control right, and issues device reset to VBC1 through M2-1 channel, and then unlocks after the device is ready; 3. At this time, the device is unlocked and runs by MCU2 and VBC1, and MCU redundancy is successful. MCU device failure locking to MCU redundancy switching and unlocking takes 5 communication cycles to complete. The redundancy switching timing diagram is shown in the appendix.

[0073] Valve control unit redundancy, fault detection and switching specific steps: 1. When MCU1 and VBC1 are in the unlocking running process, there are two working conditions for VBC redundancy switching fault detection: 1) VBC1 detects internal faults (communication abnormalities, power failures, internal PWM pulse faults, etc.) or drive reporting communication failures, VBC1 immediately locks and reports the fault state to MCU1 and MCU2; 2) MCU1 detects VBC1 communication failure (manual switching during equipment maintenance), MCU1 issues a locking instruction to VBC1; 2. MCU1 receives the fault reported by VBC1, enters the valve control redundancy switching logic, switches VBC1 to standby state, switches VBC2 to running state, and issues a reset instruction to VBC1 and VBC2; 3. VBC1 and VBC2 receive the reset instruction and perform the reset operation, VBC2 reports that the device is ready, and VBC1 enters the standby maintenance state and reports to MCU if it cannot clear the fault, or enters the standby state if VBC1 clears the fault; 4. MCU1 receives the VBC2 ready state and issues an unlock instruction through M1-2 channel; 5. VBC2 receives the unlock instruction issued by MCU1, executes the unlock operation, and the valve control unit redundancy switching is completed. The valve control unit redundancy switching logic timing is shown in Figures 4-8 .

[0074] The application replaces the traditional single set architecture by double sets of independent and cooperative master control units (MCU) and valve control units (VBC), avoids the shutdown of high-voltage power electronic equipment caused by single unit failure (such as signal interruption and control failure), ensures the continuous and stable operation of the power system, and solves the single point failure problem.

[0075] The response time of the fault switching mechanism (including valve control switching and master control switching) is compressed from the traditional 5-10 ms switching time to 5 communication cycles (each communication cycle is generally 50-100 us), which is much faster than the millisecond level window of the traditional scheme, can quickly take over the control, avoids the overvoltage breakdown or short circuit of the IGBT string circuit caused by signal interruption, reduces the impact of the fault on the downstream equipment (such as pumps, heat exchangers, and reactors), and realizes the us level fault response and switching speed.

[0076] Based on the centralized optical fiber direct control and the non-delay precise control of the double set system, the synchronization error of the on / off timing sequence of the IGBT valve string before and after switching is ≤20 ns, the consistency of the series voltage sharing is strictly maintained, the chain failure caused by "maintaining the last state" is eliminated, and the ns level synchronization precision is realized to ensure the voltage sharing balance.

[0077] The IGBT drive board integrates a double-channel optical receiving unit, through the logic of "first detecting the on signal to preferentially select", ensures that the PWM direct touch signal is not interrupted, and automatically maintains the IGBT off when there is no signal, strengthens the safety mechanism, realizes the continuity of the drive signal and self-adaptive selection.

[0078] The master control unit monitors the state of its own hardware (CPU, memory, communication interface) and software, and the valve control unit monitors the fault of its own hardware, drive board (overvoltage, short circuit), and current acquisition, realizes the fault perception of "hardware + software + peripherals" full link, and realizes multi-level fault detection coverage.

[0079] After the failure of the master unit, the standby unit takes over the control, and the fault unit can be restored to the standby state after reset (only when it cannot be restored does it need on-site maintenance), reduces the downtime maintenance time, realizes the "online maintenance" of the system, and does not need to be shut down as a whole when the valve control or master control is repaired and replaced, greatly improves the convenience of equipment maintenance, and realizes fault self-recovery and standby switching.

[0080] The valve control unit is integrated in a 6U chassis (including backplane, power board, optical input and output board, etc. can be disassembled), the master control unit is integrated in a 4U chassis (including DIDO board, communication management board), the board cards are connected through standardized slots, can be quickly disassembled and replaced, simplify maintenance, realize modular design and reduce maintenance cost.

[0081] It is suitable for flexible AC / DC power transmission and distribution system, high-voltage frequency converter, STATCOM, SVG, APF, energy storage converter PCS and other equipment, meets different high-voltage power conversion requirements, has strong compatibility, and realizes wide adaptation to high-voltage power electronic scenes.

[0082] When the main control unit issues the unlocking instruction to the double-set valve control, mutual exclusion logic (only one set is unlocked each time) is adopted, the working states of the valve control units are mutually exclusive, the control conflict caused by the simultaneous output of the driving signals of the double-set units is eliminated, and the mutual exclusion unlocking logic is realized to avoid the conflict.

[0083] The above is only an embodiment of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application is included in the scope of the claims of the present application.

Claims

1. A dual-redundant system for IGBT series valve master control and valve control device, characterized in that, The system includes: two main control units, two valve control units, and multiple IGBT driver boards; The main control units in the dual main control units are interconnected. Each main control unit in the dual main control units is connected to the dual valve control units. Each valve control unit in the dual valve control units is connected to the multiple IGBT driver boards. The currently running main control unit and valve control unit are respectively used as the primary main control unit and the primary valve control unit, and the other main control unit and valve control unit are respectively used as the backup main control unit and the backup valve control unit. The main valve control unit is used to lock out and report valve control faults if an internal fault is detected when the system is in operation. The main control unit is used to trigger valve control switching logic, generate and issue valve control switching command when receiving the valve control fault, and trigger main control switching logic to generate main control unit switching signal when an internal fault is detected, so as to realize the redundancy switching of the main control unit. The backup valve control unit is used to unlock when it is in a locked state if it receives the valve control switching command, thereby realizing the redundancy switching of the valve control unit, and to generate a drive signal by using PWM modulation according to the modulation wave signal sent by the main control unit. Each IGBT driver board is used to control the IGBTs corresponding to each IGBT driver board according to the drive signal.

2. The system according to claim 1, characterized in that, The main control unit is specifically used to perform a self-test using a preset self-test program when it is in operation, obtain the self-test result, trigger the main control switching logic and generate a main control unit switching signal when the self-test result is an internal fault, and trigger the control logic and generate and send the modulation wave signal when the self-test result is normal operation. The backup master control unit is specifically used to, when in a locked state, unlock itself upon receiving a master control unit switching signal, trigger a preset control program, and generate and send the modulated wave signal.

3. The system according to claim 1, characterized in that, The main valve control unit is specifically used to perform a pre-set valve control self-test program when it is in the unlocked state, obtain the test result, and lock the valve control unit when the test result is a valve control fault, and report the valve control fault.

4. The system according to claim 1, characterized in that, Each IGBT driver board is also used to monitor the IGBTs corresponding to each IGBT driver board and report the IGBT operating status and the driver board operating status. The main valve control unit is also used to report fault information of the faulty IGBT or the faulty driver board when the IGBT is in a faulty operating state or the driver board is in a faulty operating state. The main control unit is also used to generate an alarm signal for the faulty IGBT or the faulty driver board based on the fault information.

5. The system according to claim 1, characterized in that, Each of the dual main control units uses a 4U chassis. The 4U chassis includes: a 4U backplane, a main control board, a DIDO board, and a communication management board; The main control board, the DIDO board, and the communication management board are mechanically fixed and electrically connected to the 4U backplane via slots. The main control board is connected to the dual valve control unit.

6. The system according to claim 5, characterized in that, The main control board is equipped with a built-in fault detection module, which stores a preset self-test program. The built-in fault detection module is used to detect the operating status of the main control unit using the preset self-test program, so as to determine whether the main control unit has failed.

7. The system according to claim 1, characterized in that, Each of the dual valve control units uses a valve control chassis. The valve control chassis includes: a backplane, a power board, a main control board, and multiple optical transceiver boards; The power board, the main control board, and the multiple optical transceiver boards are mechanically fixed and electrically connected to the backplane via slots. The main control board is connected to the dual main control units, and each optical transceiver board is connected to the IGBT driver board corresponding to each optical transceiver board. The power supply board is used to supply power to the backplane, the main control board and the plurality of optical transceiver boards; The backplane is used for signal interaction between the various boards; The main control board is used to generate the drive signal based on the modulated wave signal using the PWM modulation. Each optical transceiver board is used to send the drive signal to each IGBT driver board.

8. The system according to claim 7, characterized in that, Each optical transceiver card includes multiple independent optical transceiver channels, and each optical transceiver channel includes a downlink channel and an uplink channel; The downlink channel and the uplink channel are respectively connected to the IGBT driver board corresponding to each group of optical transceiver channels; The downlink channel is used to send the drive signal to the IGBT driver board corresponding to each optical transceiver channel; The uplink channel is used to receive the operating status of each IGBT driver board and the operating status of the corresponding IGBTs on each IGBT driver board.

9. The system according to claim 7, characterized in that, The main control board includes a fault detection module; The fault detection module is used to monitor valve control faults of the main valve control unit; it is also used to receive and send driver board faults and IGBT faults reported by the IGBT driver board. The main control unit is also used to generate a fault processing signal based on the fault of the driver board or the fault of the IGBT using a preset strategy, so as to process the fault of the IGBT driver board or the IGBT.

10. The system according to any one of claims 1-9, characterized in that, Each IGBT driver board includes: a first optical receiving unit, a second optical receiving unit, and a signal selection module; The signal selection module is connected to one end of the first optical receiving unit and one end of the second optical receiving unit, respectively. The other end of the first optical receiving unit is connected to one of the valve control units in the dual valve control unit, and the other end of the second optical receiving unit is connected to the other valve control unit in the dual valve control unit.

11. The system according to claim 10, characterized in that, The signal selection module is used to select the drive signal of the first optical receiving unit when the first optical receiving unit receives the drive signal, select the drive signal of the second optical receiving unit when the second optical receiving unit receives the drive signal, and control the IGBT corresponding to each IGBT driver board to turn off when neither the first optical receiving unit nor the second optical receiving unit receives the drive signal.

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