A servo system energy feedback control method based on variable load working condition self-adaption

Abstract

The application discloses a kind of based on variable load working condition self-adaptive servo system energy feedback control method, specifically related to industrial control system technical field, the method described in the application is read by servo controller bus overvoltage boundary, feedback current limit, brake temperature rise limit, channel bit number rule and execution port number, generates acceptance criterion, order position mapping and port mapping;Bus voltage, feedback current, brake temperature, torque instruction and speed feedback are collected periodically, and output keeps identification or release energy trigger identification;After release energy trigger, bus containment level and energy distribution constraint term are generated, and are converted into acceptance margin, channel bit number encoding value and control word and are written into execution port.The method can coordinate feedback, bus temporary storage and brake peak clipping in the initial stage of variable load release energy, reduce invalid switching, suppress bus voltage fluctuation and feedback current mutation, reduce brake branch heat concentration risk, improve the stability and safety of energy processing under continuous variable load working condition.

Description

Technical Field

[0001] This invention relates to the field of industrial control systems, and in particular to an energy feedback control method for servo systems based on adaptive variable load conditions. Background Technology

[0002] The field of industrial control system technology involves automated control systems for the operation of industrial production equipment. Its core aspects include industrial control logic construction, actuator motion adjustment, drive energy transfer, equipment status feedback, operating condition adaptation, control link coordination, and system safety protection. Overall, it revolves around the control requirements of production equipment in scenarios of continuous processing, reciprocating motion, load changes, and multi-axis coordination, and systematically organizes the operational relationships between the control layer, drive layer, execution layer, and feedback layer. Among them, the traditional servo system energy feedback control method refers to the control method that guides and regulates the regenerative energy generated by the servo system during load changes, inertia release, deceleration operation and external force reverse drag. It usually adopts technical means such as preset working condition matching, fixed control threshold constraints, braking energy consumption, feedback channel switching, energy flow distribution, drive loop coordination, operating status discrimination and working condition gear switching to control the generation, temporary storage, consumption and feedback of regenerative energy in the servo system.

[0003] Existing servo energy feedback control is mostly triggered by bus voltage exceeding limits or preset operating conditions. The feedback unit, bus temporary storage and braking branch are usually switched according to fixed thresholds. They do not combine torque unloading, load reverse drag and feedback current and braking temperature rise margin for periodic joint judgment, which leads to lag in regenerative energy processing and is prone to bus voltage fluctuation, feedback current abrupt change and concentrated heat generation in the braking branch. Summary of the Invention

[0004] The main objective of this invention is to provide an energy feedback control method for servo systems based on adaptive variable load conditions, which can effectively solve the problems of lagging energy regeneration processing and unstable channel allocation in existing servo systems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A servo system energy feedback control method based on adaptive variable load conditions includes the following steps: The servo controller reads the bus overvoltage boundary, feedback current limit, braking temperature rise limit, channel tag number rules and execution port number, and generates acceptance criteria, sequence mapping and port mapping; The servo controller collects and latches the bus voltage, feedback current, braking temperature, torque command and speed feedback cycle by cycle, calculates the change direction of torque command and speed feedback in adjacent cycles, and outputs a hold flag or an energy release trigger flag. This cycle's output will remain in operation after the identifier is maintained until the next cycle; After the energy release trigger flag is output in this period, the bus protection margin and voltage rise status are calculated based on the bus overvoltage boundary and the bus voltage of the adjacent period, and the bus capacity level is generated. Based on the aforementioned acceptance criteria, the bus capacity level, feedback current, and braking temperature are correlated and determined to generate energy distribution constraints. The energy allocation constraints are converted into the carrying capacity of the feedback channel, bus buffer channel and braking channel. The channel number is determined according to the carrying capacity and sequence mapping. The channel number encoding value is generated and converted into the feedback conduction, bus buffer and braking peak reduction control words according to the port mapping. The words are written to the execution port of the servo driver. The carrying capacity is refreshed according to the feedback of the execution port to generate feedback results.

[0006] Preferably, the acceptance criterion, sequence mapping, and port mapping are generated in the following manner: The bus overvoltage boundary, feedback current limit and braking temperature rise limit are respectively written into the bus boundary item, feedback boundary item and braking boundary item of the acceptance criterion; Write the sequence code relationship of feedback channel, bus temporary storage channel and braking channel in the channel tag number rule into the sequence mapping; Write the corresponding port numbers for feedback conduction, bus buffering, and braking peak shaving from the execution port numbers into the port mapping.

[0007] Preferably, the hold flag or release trigger flag is generated in the following manner: The torque decrease is obtained by subtracting the torque command amplitude of the current cycle from the torque command amplitude of the previous cycle. The speed change is obtained by subtracting the speed feedback of the previous cycle from the speed feedback of the current cycle. Based on the encoder positive direction and the preset load reverse direction calibration value, it is determined whether the speed change points to the direction of the load driving the servo motor. When the speed change does not point in the direction of the load driving the servo motor, it is marked as non-reverse thrust state; when the speed change points in the direction of the load driving the servo motor and the torque drop is greater than zero, it is marked as torque unloading state; when the torque drop is not greater than zero, it is marked as load reverse drag state. The output holds the indicator in non-reverse thrust state, and the output releases the indicator in torque unloading state or load reverse drag state.

[0008] Preferably, the bus protection margin and voltage rise status are calculated as follows: After the output release trigger flag is displayed, the bus overvoltage boundary in the bus boundary item is called. The bus protection margin is obtained by subtracting the bus voltage of the current cycle from the bus overvoltage boundary. The difference is set to zero when it is less than zero. The bus voltage of the current cycle is compared with the bus voltage of the previous cycle. If the bus voltage of the current cycle is greater than the bus voltage of the previous cycle, a raised state is generated; otherwise, a non-raised state is generated.

[0009] Preferably, the busbar capacity rating is generated according to the following rules: When the bus protection margin is greater than zero and the voltage rise state is not risen, an absorption level is generated; when the bus protection margin is greater than zero and the voltage rise state is risen, a shunt level is generated. When the bus protection margin is zero and the bus voltage in this cycle does not exceed the bus overvoltage boundary, a suppression level is generated; when the bus voltage in this cycle exceeds the bus overvoltage boundary, an overvoltage control level is generated.

[0010] Preferably, the energy allocation constraint is generated in the following manner: Call the feedback boundary item and braking boundary item in the acceptance criterion, subtract the feedback current of this cycle from the feedback current limit to obtain the feedback current margin, and subtract the braking temperature of this cycle from the braking temperature rise limit to obtain the braking temperature rise margin. All negative values ​​are set to zero. Under the absorbable level, energy distribution constraints are generated, including bus temporary storage and braking without peak reduction; when the feedback current margin is greater than zero, write "feedback can accept", otherwise write "feedback cannot accept". Under the current shunting level, generate energy allocation constraints that can be temporarily stored on the bus; write feedback can be accepted when the feedback current margin is greater than zero, otherwise write feedback cannot be accepted; write braking can be peak-shaving when the braking temperature rise margin is greater than zero, otherwise write braking does not shaving. Under the suppression level or overvoltage control level, generate energy distribution constraints including those that cannot be temporarily stored on the bus; write feedback can be accepted when the feedback current margin is greater than zero, otherwise write feedback cannot be accepted; write braking can be peak-shaving when the braking temperature rise margin is greater than zero, otherwise write braking without peak-shaving.

[0011] Preferably, the bearing margin is converted according to the following rules: The energy allocation constraint includes that when feedback is available, the feedback current margin is used as the feedback channel's capacity margin; otherwise, it is set to zero. Energy allocation constraints include: when the busbar can be temporarily stored, the busbar protection margin is used as the busbar temporary storage channel capacity; otherwise, it is set to zero. The energy distribution constraint includes using the braking temperature rise margin as the braking channel bearing margin when braking can reduce peak loads; otherwise, it is set to zero.

[0012] Preferably, the channel number is determined according to the following rules: When the feedback channel capacity is greater than zero, the feedback channel is written to the first control bit according to the sequence bit mapping; otherwise, it is written to the empty bit. When the capacity of the busbar temporary storage channel is greater than zero, the busbar temporary storage channel is written to the buffer bit; otherwise, it is written to the empty bit. When the braking channel has a carrying capacity greater than zero, the braking channel is written to the peak-shaving position; otherwise, it is written to the empty position. The channel number encoding value is generated by the first connecting position, buffer position, peak-shaving position and empty position.

[0013] Preferably, the control word is converted according to the following rules: When the first control bit is written to the feedback channel, the feedback conduction port number is determined according to the port mapping, and the channel bit number encoding value corresponding to the first control bit is written to the port number as the feedback conduction control word. When writing the buffer bit into the bus temporary storage channel, the bus buffer port number is determined according to the port mapping, and the channel bit number encoding value corresponding to the buffer bit is written as the bus buffer control word into the port number. When writing the peak reduction bit into the braking channel, the braking peak reduction port number is determined based on the port mapping, and the channel bit number encoding value corresponding to the peak reduction bit is written into the port number as the braking peak reduction control word; no new conduction permission is generated for the empty bit.

[0014] Preferably, the feedback result is generated in the following manner: The feedback from the execution port includes the feedback current, bus voltage, and braking temperature after execution; The feedback channel feedback result is generated by subtracting the feedback current after execution from the feedback current limit. The difference is set to zero if the difference is less than zero or if the energy allocation constraint includes feedback that cannot be accepted. The bus temporary storage channel feedback result is generated by subtracting the bus voltage after execution from the bus overvoltage boundary. The difference is set to zero if it is less than zero or if the energy distribution constraint includes bus non-temporary storage. The braking channel feedback result is generated by subtracting the braking temperature after execution from the braking temperature rise limit. The difference is less than zero or the energy distribution constraint is set to zero when braking does not reduce peak speed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention first identifies torque unloading or load reverse drag trends in each control cycle, and only enters the energy allocation judgment when there is a risk of energy release, reducing invalid channel switching. Bus capacity levels are divided based on bus protection margin and voltage rise status, and constraints are formed by combining feedback current margin and braking temperature rise margin, ensuring that regenerated energy is preferentially allocated to channels that still have the capacity to handle the load. Simultaneously, the margins of each channel are refreshed based on feedback from the execution port, preventing overload of feedback channels, continued bus rise, or overheating of braking branches, thereby improving the stability and safety of energy handling under continuous variable load conditions. Attached Figure Description

[0016] Figure 1 This is an overall flowchart of the energy feedback control method of the present invention; Figure 2 This is a state machine diagram for generating the retention flag and the energy release trigger flag of the present invention; Figure 3 This is a flowchart illustrating the generation process of the busbar capacity level according to the present invention. Figure 4 A flowchart for generating the energy allocation constraint terms of this invention; Figure 5 This is a block diagram of the channel tag number and port mapping of the present invention; Figure 6 This is a flowchart of the execution port feedback refresh closed-loop process of the present invention. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] Please see Figure 1 This invention discloses an energy feedback control method for a servo system based on adaptive variable load conditions, comprising the following steps: The servo controller reads the bus overvoltage boundary, feedback current limit, braking temperature rise limit, channel tag number rules and execution port number, and generates acceptance criteria, sequence mapping and port mapping; The servo controller collects and latches the bus voltage, feedback current, braking temperature, torque command and speed feedback cycle by cycle, calculates the change direction of torque command and speed feedback in adjacent cycles, and outputs a hold flag or an energy release trigger flag. This cycle's output will remain in operation after the identifier is maintained until the next cycle; After the energy release trigger flag is output in this period, the bus protection margin and voltage rise status are calculated based on the bus overvoltage boundary and the bus voltage of the adjacent period, and the bus capacity level is generated. Based on the aforementioned acceptance criteria, the bus capacity level, feedback current, and braking temperature are correlated and determined to generate energy distribution constraints. The energy allocation constraints are converted into the carrying capacity of the feedback channel, bus buffer channel and braking channel. The channel number is determined according to the carrying capacity and sequence mapping. The channel number encoding value is generated and converted into the feedback conduction, bus buffer and braking peak reduction control words according to the port mapping. The words are written to the execution port of the servo driver. The carrying capacity is refreshed according to the feedback of the execution port to generate feedback results.

[0019] This technical solution is mainly applied to servo drive systems in industrial production equipment, suitable for variable load conditions such as sudden load drops, inertial release, external force reverse drag, continuous start-stop, and reciprocating motion. In this scenario, the servo motor generates regenerative energy when decelerating or being reverse-driven by the load, and this energy is fed back to the DC bus. This technical solution uses a servo controller to process the bus voltage, feedback current, braking temperature, torque command, and speed feedback cycle by cycle to achieve adaptive distribution control of regenerative energy among the feedback channel, bus temporary storage channel, and braking channel.

[0020] Furthermore, before entering cycle-by-cycle control, the servo controller first reads the bus overvoltage boundary, feedback current limit, braking temperature rise limit, channel tag number rule, and execution port number from the parameter storage area, control configuration area, or field debugging writing area of ​​the servo driver. Among them, the bus overvoltage boundary is used to limit the upper limit of the allowable voltage of the DC bus, the feedback current limit is used to limit the current range that the feedback channel can withstand, and the braking temperature rise limit is used to limit the temperature rise range that the braking branch is allowed to continue to participate in peak shaving. The above limits can be the equipment factory parameters, driver rated parameters, or protection parameters written during the debugging stage.

[0021] The servo controller writes the bus overvoltage boundary, feedback current limit, and braking temperature rise limit into the bus boundary item, feedback boundary item, and braking boundary item of the acceptance criterion, respectively. The acceptance criterion is used to compare and judge the bus voltage, feedback current, and braking temperature in subsequent control cycles, so that the controller can determine whether the bus still has temporary space, whether the feedback channel still has acceptance capacity, and whether the braking branch still has peak shaving capacity based on existing hardware detection data, thereby providing a unified judgment basis for the subsequent generation of energy distribution constraint items.

[0022] The servo controller also writes the sequence encoding relationship of the feedback channel, bus buffer channel and braking channel in the channel tag number rule into the sequence mapping, and writes the port number corresponding to feedback conduction, bus buffer and braking peak reduction in the execution port number into the port mapping; The busbar temporary storage channel consists of a DC busbar and its busbar capacitor. The busbar protection margin is used to represent the voltage space at which the busbar capacitor continues to absorb regenerative energy. Among them, the sequence bit mapping is used to convert the subsequently determined channel bit number into a recognizable channel sequence bit code, and the port mapping is used to determine the hardware execution port for the corresponding control word to be written, so that the feedback conduction control, bus buffer control and braking peak shaving control can act on the corresponding execution ports respectively.

[0023] In one optional implementation, the channel numbering rule can employ a fixed-length bit-segment encoding method. The servo controller pre-sets channel codes for each channel, where the vacant bit code is 00, the feedback channel code is 01, the bus temporary storage channel code is 10, and the braking channel code is 11; simultaneously, the first connecting bit, buffer bit, and peak-shaving bit are set as the first, second, and third segments of the channel number encoding value, respectively. After determining each channel number, the servo controller writes the channel code corresponding to the first connecting bit into the first segment, the channel code corresponding to the buffer bit into the second segment, and the channel code corresponding to the peak-shaving bit into the third segment, and the channel number encoding value is generated by concatenating the bits.

[0024] For example, when the feedback channel is written to the first control bit, the bus buffer channel is written to the buffer bit, and the braking channel is written to the idle bit, the servo controller writes 01 to the first segment, 10 to the second segment, and 00 to the third segment, and combines these three fields to obtain the channel number encoding value for the current cycle. The port mapping pre-records the correspondence between the feedback conduction port, the bus buffer port, and the braking peak-shaving port and the above segments; when the first control bit is the feedback channel, the servo controller extracts the encoding value of the first segment as the feedback conduction control word and writes it to the feedback conduction port; when the buffer bit is the bus buffer channel, it extracts the encoding value of the second segment as the bus buffer control word and writes it to the bus buffer port; when the peak-shaving bit is the braking channel, it extracts the encoding value of the third segment as the braking peak-shaving control word and writes it to the braking peak-shaving port; when the corresponding segment is 00, no new conduction permission is generated for the corresponding port.

[0025] Example 1, please refer to Figure 2 In this embodiment, based on the already generated acceptance criteria, sequence mapping, and port mapping, a further generation of a hold flag or release trigger flag is performed. In each control cycle, the servo controller reads the torque command of the current cycle, the torque command of the previous cycle, the speed feedback of the current cycle, and the speed feedback of the previous cycle. The torque command of the current cycle can be obtained from the motion control command buffer or the torque setpoint data output by the servo controller. The torque command of the previous cycle can be provided by the cycle data buffer written at the end of the previous control cycle. The speed feedback of the current cycle and the speed feedback of the previous cycle can be acquired and latched by the encoder feedback port.

[0026] The torque command amplitude is the absolute value of the torque command value or an equivalent value used to characterize the magnitude of the torque command, used to represent the torque intensity required by the servo controller to output from the servo motor within the corresponding control cycle. The servo controller subtracts the torque command amplitude of the current cycle from the torque command amplitude of the previous cycle to obtain the torque decrease. When the torque decrease is greater than zero, it indicates that there is a decrease in torque output demand in the current cycle compared to the previous cycle. When the torque decrease is not greater than zero, it indicates that there is no decrease in torque output demand or no decrease in torque output demand in the current cycle.

[0027] The servo controller obtains the speed change by subtracting the speed feedback from the previous cycle from the current cycle's speed feedback. Based on the encoder's positive direction and the preset load reverse thrust direction calibration value, it determines whether the speed change points in the direction the load drives the servo motor. The encoder's positive direction can be determined during the equipment installation and commissioning phase through servo motor trial operation. The preset load reverse thrust direction calibration value is used to indicate the direction in which the load-side inertia, gravity, or external force may drive the servo motor to rotate, so that the determination of the direction of the speed change can correspond to the actual load reverse thrust relationship.

[0028] When the speed change does not point in the direction of the load driving the servo motor, the servo controller marks it as non-reverse thrust state and outputs a hold flag. The hold flag indicates that no load reverse thrust trend that requires the activation of regenerative energy feedback shunting judgment is detected in this cycle. The servo controller maintains the current operating state until the next cycle and continues to perform routine acquisition and monitoring of bus voltage, feedback current and braking temperature.

[0029] When the speed change points in the direction of the load driving the servo motor and the torque decrease is greater than zero, the servo controller marks it as torque unloading state and outputs an energy release trigger flag. This state indicates that the servo controller's torque output demand for the servo motor has decreased, while the load side still has a tendency to drive the servo motor. The servo motor may switch from the drive output state to the regenerative energy return state, thus requiring the subsequent judgment process of bus protection margin, voltage rise state, and bus capacity level.

[0030] When the speed change points in the direction of the load driving the servo motor and the torque drop is not greater than zero, the servo controller marks it as a load reverse drag state and outputs an energy release trigger flag. This state indicates that although the current torque output demand has not decreased, the speed change direction has shown a trend of the load side driving the servo motor. This may be due to inertial release, external force reverse drag, or the load side movement driving the servo motor to generate regenerative energy. Therefore, the non-reverse push state outputs a hold flag, and the torque unloading state or load reverse drag state outputs an energy release trigger flag.

[0031] Example 2, please refer to Figure 3This embodiment, based on the already generated holding flag or release trigger flag in Embodiment 1, further generates bus protection margin, voltage rise state, and bus tolerance level. When the release trigger flag is output in this cycle, the servo controller calls the bus boundary item that accepts the criterion, reads the bus overvoltage boundary from the bus boundary item, and reads the bus voltage of this cycle and the bus voltage of the previous cycle. The bus overvoltage boundary can be the protection boundary set by the servo driver at the factory, the rated protection value stored in the equipment parameter area, or the safety threshold written during the debugging stage. The bus voltage of this cycle and the bus voltage of the previous cycle can be collected by the bus voltage sampling circuit in the corresponding control cycle and latched by the servo controller.

[0032] The servo controller obtains the bus protection margin by subtracting the bus voltage of the current cycle from the bus overvoltage boundary. The bus protection margin is used to represent the voltage space that the DC bus still retains from the bus overvoltage boundary and serves as the control basis for determining whether the bus can continue to temporarily store regenerative energy. When the calculated difference is less than zero, it indicates that the bus voltage of the current cycle has exceeded the bus overvoltage boundary. The servo controller sets the bus protection margin to zero to prevent subsequent processes from misjudging the bus state that has exceeded the protection boundary as still having usable temporary storage space.

[0033] The servo controller further compares the current cycle bus voltage with the previous cycle bus voltage. When the current cycle bus voltage is greater than the previous cycle bus voltage, a voltage rise state is generated; when the current cycle bus voltage is not greater than the previous cycle bus voltage, a voltage non-rise state is generated. The voltage rise state is used to indicate whether there is an upward trend in the DC bus voltage between adjacent control cycles. When a voltage rise state exists, it indicates that regenerative energy may be being fed back to the DC bus or the bus absorption capacity is becoming strained. When the voltage non-rise state exists, it indicates that the current cycle bus voltage has not continued to rise, and the temporary risk on the bus side is relatively low.

[0034] After obtaining the bus protection margin and voltage rise status, the servo controller generates the bus tolerance level according to preset rules. When the bus protection margin is greater than zero and the voltage rise status is not risen, it means that the DC bus still has room to move away from the overvoltage boundary and the voltage has not continued to rise. The servo controller generates an acceptable tolerance level. When the bus protection margin is greater than zero and the voltage rise status is risen, it means that the DC bus has not yet reached the overvoltage boundary but there is a continuing upward trend. The servo controller generates a shunt requirement level.

[0035] When the bus protection margin is zero and the bus voltage in this cycle does not exceed the bus overvoltage boundary, it indicates that the DC bus is approaching or has reached the overvoltage boundary. Continuing to temporarily store regenerative energy on the bus side poses a protection risk, and the servo controller generates a suppression level. When the bus voltage in this cycle exceeds the bus overvoltage boundary, it indicates that the DC bus has crossed the protection boundary, and the servo controller generates an overvoltage takeover level. Through the above rules, the bus capacity level is divided into absorbable level, shunting level, suppression level, and overvoltage takeover level, so that subsequent energy allocation constraints can determine the control relationship between bus temporary storage, feedback takeover, and braking peak shaving based on the current bus capacity status.

[0036] Example 3, please refer to Figure 4 In this embodiment, based on the already generated acceptance criteria and combined with the bus capacity level obtained in Embodiment 2, energy distribution constraint terms are further generated. The servo controller calls the feedback boundary terms and braking boundary terms in the acceptance criteria, reads the feedback current limit from the feedback boundary terms, reads the braking temperature rise limit from the braking boundary terms, and reads the feedback current and braking temperature of the current cycle. The feedback current of the current cycle can be obtained from the current sampling circuit of the feedback unit or the feedback status feedback port, and the braking temperature of the current cycle can be obtained from the temperature sampling circuit of the braking branch. The two are used to represent the actual acceptance status of the feedback channel and the braking branch in the current control cycle, respectively.

[0037] The braking temperature for this cycle can be the temperature value directly collected by the braking branch temperature sampling circuit. When the braking temperature rise limit is set based on the initial temperature or the ambient reference temperature, the servo controller converts the directly collected temperature value into a braking temperature rise value under the same measurement reference as the braking temperature rise limit, and uses this braking temperature rise value as the braking temperature for this cycle for subsequent calculation of the braking temperature rise margin.

[0038] The servo controller obtains the feedback current margin by subtracting the feedback current of the current cycle from the feedback current limit, and obtains the braking temperature rise margin by subtracting the braking temperature of the current cycle from the braking temperature rise limit. The feedback current margin is used to represent the current space that the feedback channel can still accept relative to the allowable acceptance boundary in the current cycle, and the braking temperature rise margin is used to represent the heat acceptance space that the braking branch can still participate in peak shaving relative to the allowable temperature rise boundary. When the calculated result of the feedback current margin or the braking temperature rise margin is negative, the servo controller will set the corresponding margin to zero to avoid exceeding the control permission of the hardware acceptance capacity when generating energy distribution constraints in the future.

[0039] When the bus capacity level is at the absorbable level, the servo controller generates energy distribution constraints including bus temporary storage and braking without peak shaving. At this time, the bus still has a certain protection margin and is not in a voltage rise trend, so the bus temporary storage channel is allowed to participate in buffering, while the braking branch is not actively called for peak shaving. At this level, the servo controller continues to determine whether the feedback current margin is greater than zero. If the feedback current margin is greater than zero, write "feedback can be accepted"; if the feedback current margin is not greater than zero, write "feedback cannot be accepted", so that whether the feedback channel participates in acceptance is determined by its actual current margin.

[0040] When the bus capacity level is required to shunt the current, the servo controller generates energy allocation constraints that can be temporarily stored on the bus. At this time, the bus still has a protection margin but has already shown a voltage rise, indicating that the regenerative energy reinjection trend needs to be handled by multiple channels working together. The servo controller determines whether the feedback current margin is greater than zero. If the feedback current margin is greater than zero, write "feedback can accept"; otherwise, write "feedback cannot accept". At the same time, it determines whether the braking temperature rise margin is greater than zero. If the braking temperature rise margin is greater than zero, write "braking can reduce peaks"; otherwise, write "braking does not reduce peaks". Thus, while retaining the temporary storage function of the bus, a current shunting constraint is formed based on the actual margin of the feedback channel and the braking branch.

[0041] When the bus capacity level is either suppressed or overvoltage control level, the servo controller generates energy allocation constraints that include those that the bus cannot temporarily store. Suppressed level indicates that the bus protection margin is already limited, and overvoltage control level indicates that the bus voltage in this cycle has exceeded the bus overvoltage boundary. In these cases, the bus temporary storage channel is no longer used as a path to continue absorbing regenerative energy. The servo controller still determines the feedback side constraints according to the rule that feedback can be accepted when the feedback current margin is greater than zero, and that feedback cannot be accepted otherwise. It also determines the braking side constraints according to the rule that braking peak reduction can be achieved when the braking temperature rise margin is greater than zero, and that braking peak reduction is not achieved otherwise. This generates energy allocation constraints corresponding to the current bus status, feedback acceptance capacity, and braking peak reduction capacity.

[0042] Example 4, please refer to Figure 5 In this embodiment, based on the energy allocation constraint terms already generated in Embodiment 3, the energy allocation constraint terms are further converted into the capacity margin of each channel, and the channel tag number, control word, and feedback result are determined according to the capacity margin. The energy allocation constraint terms are used to limit whether the feedback channel, bus temporary storage channel, and braking channel are allowed to participate in regenerative energy processing in the current control cycle. The capacity margin is used to represent the current space, voltage space, or temperature rise space that the corresponding channel can still accept in the current control cycle, so that the generation of channel tag number and control word has a corresponding execution basis.

[0043] During the capacity conversion process, the servo controller reads the feedback current capacity, bus protection capacity, and braking temperature rise capacity obtained in Example 3, and reads the constraints in the energy allocation constraints regarding feedback being able to be accepted, feedback not being able to be accepted, bus being able to be temporarily stored, bus not being able to be temporarily stored, braking being able to reduce peaks, and braking not reducing peaks. When the energy allocation constraint includes feedback being able to be accepted, the feedback current capacity is used as the feedback channel capacity; otherwise, the feedback channel capacity is set to zero. When the energy allocation constraint includes bus being able to be temporarily stored, the bus protection capacity is used as the bus temporary storage channel capacity; otherwise, the bus temporary storage channel capacity is set to zero. When the energy allocation constraint includes braking being able to reduce peaks, the braking temperature rise capacity is used as the braking channel capacity; otherwise, the braking channel capacity is set to zero.

[0044] Among them, the feedback channel bearing margin is used to represent the current range that the feedback channel can still bear relative to the feedback current limit; the bus temporary storage channel bearing margin is used to represent the protection space that the DC bus can still temporarily store relative to the bus overvoltage boundary; and the braking channel bearing margin is used to represent the thermal margin that the braking branch can still participate in peak shaving relative to the braking temperature rise limit. When the constraint content corresponding to any channel is that it cannot bear, cannot be temporarily stored, or does not shave peaks, even if the sampling data corresponding to the channel still exists, no corresponding effective bearing margin is generated, thus making the channel bearing margin subject to the energy distribution constraint term.

[0045] During the channel number determination process, the servo controller calls the sequence mapping and determines the number of each channel according to the feedback channel carrying capacity, the bus temporary storage channel carrying capacity, and the braking channel carrying capacity respectively. When the feedback channel carrying capacity is greater than zero, the feedback channel is written to the first control bit according to the sequence mapping; otherwise, the feedback channel is written to the empty bit. When the busbar temporary storage channel has a capacity greater than zero, the busbar temporary storage channel is written to the buffer bit according to the sequence bit mapping; otherwise, the busbar temporary storage channel is written to the empty bit. When the braking channel has a capacity greater than zero, the braking channel is written to the peak reduction bit according to the sequence bit mapping; otherwise, the braking channel is written to the empty bit.

[0046] The first takeover bit indicates that the feedback channel is permitted to participate in regenerative energy feedback in the current cycle. The buffer bit indicates that the bus storage channel is permitted to temporarily store and buffer regenerative energy in the current cycle. The peak clipping bit indicates that the braking channel is permitted to perform peak clipping on regenerative energy in the current cycle. The idle bit indicates that the corresponding channel will not generate new conduction permission in the current cycle. The servo controller generates channel tag number encoding values ​​from the first takeover bit, buffer bit, peak clipping bit, and idle bit, so as to convert the internally determined channel tag number result into an encoding form that can be further written to the execution port.

[0047] During the control word conversion process, the servo controller calls the port mapping and determines the corresponding execution port based on the channel tag number encoding value. When the first takeover bit is written to the feedback channel, the feedback conduction port number is determined according to the port mapping, and the channel tag number encoding value corresponding to the first takeover bit is written as the feedback conduction control word to that port number. When the buffer bit is written to the bus temporary storage channel, the bus buffer port number is determined according to the port mapping, and the channel tag number encoding value corresponding to the buffer bit is written as the bus buffer control word to that port number. When the peak shaving bit is written to the braking channel, the braking peak shaving port number is determined according to the port mapping, and the channel tag number encoding value corresponding to the peak shaving bit is written as the braking peak shaving control word to that port number. No new conduction permission is generated for the idle bit.

[0048] The feedback conduction control word is used to enable the feedback unit of the servo drive to participate in energy return according to the current cycle permission. The bus buffer control word is used to enable the bus temporary storage channel to participate in bus-side buffering according to the current cycle permission. The braking peak shaving control word is used to enable the braking branch to participate in peak shaving processing according to the current cycle permission. All of the above control words are determined by the channel tag number encoding value and the port mapping relationship. Their function is to convert the channel tag number result formed inside the servo controller into an execution instruction that can be recognized by the hardware execution port, so that the energy allocation constraint is implemented to the corresponding execution port.

[0049] Please see Figure 6 After the execution port completes the corresponding control action, the servo controller reads the execution port feedback, which includes the feedback current after execution, the bus voltage after execution, and the braking temperature after execution. The feedback current after execution can be obtained by the current sampling circuit or the status feedback port of the feedback unit, the bus voltage after execution can be obtained by the bus voltage sampling circuit, and the braking temperature after execution can be obtained by the braking branch temperature sampling circuit. The above feedback data is used to characterize the actual execution status of each channel after the control word is written to the execution port.

[0050] The servo controller generates the feedback channel feedback result by subtracting the feedback current after execution from the feedback current limit. The difference is set to zero if it is less than zero or if the energy allocation constraint includes feedback that cannot be accepted. The bus temporary storage channel feedback result is generated by subtracting the bus voltage after execution from the bus overvoltage boundary. The difference is set to zero if it is less than zero or if the energy allocation constraint includes bus that cannot be temporarily stored. The braking channel feedback result is generated by subtracting the braking temperature after execution from the braking temperature rise limit. The difference is set to zero if it is less than zero or if the energy allocation constraint includes braking without peak reduction. The feedback results from the feedback channel, the bus temporary storage channel, and the braking channel together constitute the refresh result corresponding to the execution port feedback in this cycle. This refresh result is used to characterize the remaining connection status of the feedback channel, the bus temporary storage channel, and the braking channel after the execution port action.

[0051] Through the above processing, the feedback channel feedback result is used to indicate the remaining state relative to the feedback current limit after the feedback channel is executed, the bus buffer feedback result is used to indicate the remaining state relative to the bus overvoltage boundary after the bus buffer is executed, and the braking channel feedback result is used to indicate the remaining state relative to the braking temperature rise limit after the braking branch is executed. The feedback result serves as a status signal or adjustment result after the execution port is activated, and is used to characterize the post-execution acceptance state of the feedback channel, bus buffer channel, and braking channel in this cycle.

[0052] Example 5: To further illustrate the present invention, this example uses a multi-axis servo unit for industrial material handling and reciprocating positioning as an example. The unit includes a first servo drive unit, a second servo drive unit, a third servo drive unit, a fourth servo drive unit, and a fifth servo drive unit. Each servo drive unit is uniformly acquired and controlled cycle by cycle by a servo controller. Each servo drive unit corresponds to a feedback channel, a bus temporary storage channel, and a braking channel, respectively. Furthermore, each servo drive unit is pre-written with bus overvoltage boundaries, feedback current limits, braking temperature rise limits, channel tag number rules, and execution port numbers. The specific values ​​in this example are only used to illustrate the processing procedure of the present invention and are not intended to limit the scope of protection of the present invention.

[0053] In this embodiment, the servo controller sets the bus overvoltage boundary to 800V, the feedback current limit to 30A, and the braking temperature rise limit to 80℃. It also assigns the feedback channel to the first control port, the bus temporary storage channel to the buffer port, and the braking channel to the peak-shaving port. The feedback conduction port number, the bus buffer port number, and the braking peak-shaving port number are written into the port mapping respectively. The braking temperature is the temperature rise value under the same measurement standard as the braking temperature rise limit, the feedback current is the current value output by the feedback unit current sampling circuit, and the bus voltage is the voltage value latched by the bus voltage sampling circuit in the corresponding control cycle.

[0054] For the first servo drive unit, within a certain control cycle, the torque command amplitude of the previous cycle is 60 N·m, and the torque command amplitude of the current cycle is also 60 N·m. The change in speed feedback in the current cycle relative to the speed feedback in the previous cycle does not point in the direction of the load driving the servo motor. The servo controller determines that the unit is in a non-reverse thrust state based on the direction of the speed change and outputs a hold flag. This hold flag indicates that the current cycle will not enter the subsequent generation process of bus protection margin, voltage rise state, and bus capacity level. The first servo drive unit maintains its current operating state until the next control cycle and continues to perform routine acquisition and monitoring of bus voltage, feedback current, and braking temperature.

[0055] For the second servo drive unit, within a certain control cycle, the torque command amplitude of the previous cycle is 75 N·m, and the torque command amplitude of the current cycle is 45 N·m. The servo controller subtracts the torque command amplitude of the current cycle from the torque command amplitude of the previous cycle to obtain the torque decrease of 30 N·m. At the same time, the change in speed feedback of the current cycle relative to the speed feedback of the previous cycle points in the direction of the load driving the servo motor. The servo controller marks this state as torque unloading state and outputs a release trigger flag. After the release trigger flag is output, the servo controller enters the process of generating bus protection margin, voltage rise state, and bus capacity level.

[0056] For the second servo drive unit, if its bus voltage in the current cycle is 760V and the bus voltage in the previous cycle is 762V, the servo controller subtracts 760V from 800V to obtain a bus protection margin of 40V, and compares the bus voltage in the current cycle with the bus voltage in the previous cycle. Since the bus voltage in the current cycle is not greater than the bus voltage in the previous cycle, a non-raised state is generated. When the bus protection margin is greater than zero and the voltage raise state is non-raised, the servo controller generates an absorbable level. If the feedback current in the current cycle is 18A, the feedback current margin is 12A. If the braking temperature rise value in the current cycle is 45℃, the braking temperature rise margin is 35℃. Under the absorbable level, the servo controller generates energy distribution constraints including bus temporary storage and braking without peak clipping, and writes feedback acceptability when the feedback current margin is greater than zero. Thus, 12A is used as the feedback channel acceptability margin, 40V is used as the bus temporary storage channel acceptability margin, and the braking channel acceptability margin is set to zero.

[0057] In the second servo drive unit, the servo controller writes the feedback channel to the first takeover bit based on the feedback channel's carrying capacity being greater than zero, writes the bus temporary storage channel to the buffer bit based on the bus temporary storage channel's carrying capacity being greater than zero, and writes the braking channel to the vacant bit based on the braking channel's carrying capacity being zero. The first takeover bit, buffer bit, and vacant bit generate the channel tag number encoding value. Subsequently, the servo controller writes the channel tag number encoding value corresponding to the first takeover bit as the feedback conduction control word to the feedback conduction port number according to the port mapping, and writes the channel tag number encoding value corresponding to the buffer bit as the bus buffer control word to the bus buffer port number. The vacant bit does not generate a new conduction permission.

[0058] For the third servo drive unit, within a certain control cycle, the torque command amplitude of the previous cycle is 50 N·m, and the torque command amplitude of the current cycle is 55 N·m. The torque decrease is not greater than zero, but the change in speed feedback in the current cycle relative to the speed feedback in the previous cycle points in the direction of the load driving the servo motor. The servo controller marks this state as the load reverse drag state and outputs an energy release trigger flag. If the bus voltage of this unit in the current cycle is 780V and the bus voltage in the previous cycle is 770V, then the bus protection margin is 20V. If the bus voltage in the current cycle is greater than the bus voltage in the previous cycle, the servo controller generates a rise state. When the bus protection margin is greater than zero and the voltage rise state is a rise state, the servo controller generates a shunt level.

[0059] For the third servo drive unit, if the feedback current in this cycle is 28A, then the feedback current margin is 2A; if the braking temperature rise value in this cycle is 50℃, then the braking temperature rise margin is 30℃. Under the current shunting level, the servo controller generates an energy allocation constraint term that can be temporarily stored on the bus, and writes "feedback can accept" based on the feedback current margin being greater than zero, and writes "braking can shaving" based on the braking temperature rise margin being greater than zero. Subsequently, the servo controller uses 2A as the feedback channel acceptance margin, 20V as the bus temporary storage channel acceptance margin, and 30℃ as the braking channel acceptance margin, and writes the feedback channel into the first control bit, the bus temporary storage channel into the buffer bit, and the braking channel into the peak shaving bit according to the sequence mapping, thereby generating a channel tag number encoding value that simultaneously includes feedback conduction, bus buffering, and braking peak shaving permission.

[0060] For the fourth servo drive unit, within a certain control cycle, after the servo controller outputs the energy release trigger flag, it reads that the bus voltage for this cycle is 800V, and the bus voltage for the previous cycle is 798V. The servo controller subtracts 800V from 800V to obtain a bus protection margin of 0V. Since the bus voltage for this cycle does not exceed the bus overvoltage boundary, a suppression level is generated. If the feedback current for this cycle is 24A, the feedback current margin is 6A. If the braking temperature rise for this cycle is 82℃, the braking temperature rise margin calculation result is negative and set to zero. Under the suppression level, the servo controller generates an energy distribution constraint item that includes the bus's non-temporary energy and writes that the feedback can be accepted and the braking does not reduce peaks. Thus, 6A is used as the feedback channel acceptance margin, the bus temporary storage channel acceptance margin is set to zero, and the braking channel acceptance margin is set to zero.

[0061] In the fourth servo drive unit, the servo controller writes the feedback channel into the first control bit based on the feedback channel bearing margin being greater than zero, writes the bus temporary storage channel into the empty bit based on the bus temporary storage channel bearing margin being zero, and writes the braking channel into the empty bit based on the braking channel bearing margin being zero. The channel bit number encoding value generated in this way only corresponds to the feedback conduction control word. The servo controller writes the feedback conduction control word into the feedback conduction port number according to the port mapping, while no new conduction permission is generated for the bus buffer port and the braking peak shaving port.

[0062] For the fifth servo drive unit, within a certain control cycle, after the servo controller outputs the energy release trigger flag, it reads that the bus voltage for this cycle is 815V, and the bus voltage for the previous cycle is 805V. Since the bus voltage for this cycle exceeds the bus overvoltage boundary, the servo controller generates an overvoltage control level and sets the bus protection margin to zero. If the feedback current for this cycle is 32A, the calculated feedback current margin is negative and set to zero. If the braking temperature rise for this cycle is 60℃, the braking temperature rise margin is 20℃. Under the overvoltage control level, the servo controller generates an energy distribution constraint item that includes the bus's non-temporary energy, and writes "feedback not acceptable" based on the zero feedback current margin, and writes "braking peak shaving" based on the greater than zero braking temperature rise margin. Thus, the feedback channel acceptance margin is set to zero, the bus temporary storage channel acceptance margin is set to zero, and 20℃ is used as the braking channel acceptance margin.

[0063] In the fifth servo drive unit, the servo controller writes the feedback channel to the idle position based on the zero margin of the feedback channel, writes the bus temporary storage channel to the idle position based on the zero margin of the bus temporary storage channel, and writes the braking channel to the peak-shaving position based on the greater than zero margin of the braking channel. Subsequently, the servo controller generates channel tag number encoding values ​​from the idle position, the idle position, and the peak-shaving position, and writes the channel tag number encoding value corresponding to the peak-shaving position as the braking peak-shaving control word to the braking peak-shaving port number according to the port mapping. No new conduction permission is generated for the feedback conduction port and the bus buffer port.

[0064] After each servo drive unit completes its corresponding control action, the servo controller reads the feedback from each execution port and obtains the feedback current, bus voltage, and braking temperature after execution. For example, if the feedback current after execution of the second servo drive unit is 20A, the bus voltage is 755V, and the braking temperature rise is 45℃, the servo controller generates a feedback channel result of 10A and a bus temporary storage channel result of 45V. Because the energy distribution constraint includes braking without peak shaving, the braking channel feedback result is set to zero. If the feedback current after execution of the third servo drive unit is 29A, the bus voltage is 776V, and the braking temperature rise is 55℃, the servo controller generates a feedback channel result of 1A, a bus temporary storage channel result of 24V, and a braking channel feedback result of 25℃.

[0065] For example, if the feedback current after the fourth servo drive unit executes is 26A, the bus voltage is 798V, and the braking temperature rise is 82℃, then the servo controller generates a feedback channel result of 4A. Due to energy allocation constraints including no temporary storage on the bus and no peak shaving during braking, the servo controller sets the feedback results of the temporary storage channel and the braking channel to zero. If the feedback current after the fifth servo drive unit executes is 31A, the bus voltage is 802V, and the braking temperature rise is 66℃, then due to energy allocation constraints including no reception of feedback and no temporary storage on the bus, the servo controller sets the feedback channel result of the temporary storage channel and the bus voltage to zero, and generates a braking channel feedback result of 14℃ by subtracting 66℃ from 80℃.

[0066] Through the different operating states of the multi-axis servo unit described above, it can be seen that under the same control method, the present invention can form different bearing margins, channel numbers, control words and feedback results according to the holding mark or energy release trigger mark, bus capacity level, feedback current margin, braking temperature rise margin and energy distribution constraints. The above process enables the servo controller to limit the regenerative energy processing path to the currently allowed feedback channel, bus temporary storage channel and braking channel under different variable load conditions.

[0067] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A servo system energy feedback control method based on adaptive variable load conditions, characterized in that, Includes the following steps: The servo controller reads the bus overvoltage boundary, feedback current limit, braking temperature rise limit, channel tag number rules and execution port number, and generates acceptance criteria, sequence mapping and port mapping; The servo controller collects and latches the bus voltage, feedback current, braking temperature, torque command and speed feedback cycle by cycle, calculates the change direction of torque command and speed feedback in adjacent cycles, and outputs a hold flag or an energy release trigger flag. This cycle's output will remain in operation after the identifier is maintained until the next cycle; After the energy release trigger flag is output in this period, the bus protection margin and voltage rise status are calculated based on the bus overvoltage boundary and the bus voltage of the adjacent period, and the bus capacity level is generated. Based on the aforementioned acceptance criteria, the bus capacity level, feedback current, and braking temperature are correlated and determined to generate energy distribution constraints. The energy allocation constraints are converted into the carrying capacity of the feedback channel, bus buffer channel and braking channel. The channel number is determined according to the carrying capacity and sequence mapping. The channel number encoding value is generated and converted into the feedback conduction, bus buffer and braking peak reduction control words according to the port mapping. The words are written to the execution port of the servo driver. The carrying capacity is refreshed according to the feedback of the execution port to generate feedback results.

2. The method according to claim 1, characterized in that, The acceptance criteria, sequence mapping, and port mapping are generated as follows: The bus overvoltage boundary, feedback current limit and braking temperature rise limit are respectively written into the bus boundary item, feedback boundary item and braking boundary item of the acceptance criterion; Write the sequence code relationship of feedback channel, bus temporary storage channel and braking channel in the channel tag number rule into the sequence mapping; Write the corresponding port numbers for feedback conduction, bus buffering, and braking peak shaving from the execution port numbers into the port mapping.

3. The method according to claim 1, characterized in that, The retention flag or energy release trigger flag is generated in the following manner: The torque decrease is obtained by subtracting the torque command amplitude of the current cycle from the torque command amplitude of the previous cycle. The speed change is obtained by subtracting the speed feedback of the previous cycle from the speed feedback of the current cycle. Based on the encoder positive direction and the preset load reverse direction calibration value, it is determined whether the speed change points to the direction of the load driving the servo motor. When the speed change does not point in the direction of the load driving the servo motor, it is marked as non-reverse thrust state; when the speed change points in the direction of the load driving the servo motor and the torque drop is greater than zero, it is marked as torque unloading state; when the torque drop is not greater than zero, it is marked as load reverse drag state. The output holds the indicator in non-reverse thrust state, and the output releases the indicator in torque unloading state or load reverse drag state.

4. The method according to claim 2, characterized in that, The bus protection margin and voltage rise status are calculated as follows: After the output release trigger flag is displayed, the bus overvoltage boundary in the bus boundary item is called. The bus protection margin is obtained by subtracting the bus voltage of the current cycle from the bus overvoltage boundary. The difference is set to zero when it is less than zero. The bus voltage of the current cycle is compared with the bus voltage of the previous cycle. If the bus voltage of the current cycle is greater than the bus voltage of the previous cycle, a raised state is generated; otherwise, a non-raised state is generated.

5. The method according to claim 4, characterized in that, The busbar capacity rating is generated according to the following rules: When the bus protection margin is greater than zero and the voltage rise state is not risen, an absorption level is generated; when the bus protection margin is greater than zero and the voltage rise state is risen, a shunt level is generated. When the bus protection margin is zero and the bus voltage in this cycle does not exceed the bus overvoltage boundary, a suppression level is generated; when the bus voltage in this cycle exceeds the bus overvoltage boundary, an overvoltage control level is generated.

6. The method according to claim 5, characterized in that, The energy allocation constraint terms are generated as follows: Call the feedback boundary item and braking boundary item in the acceptance criterion, subtract the feedback current of this cycle from the feedback current limit to obtain the feedback current margin, and subtract the braking temperature of this cycle from the braking temperature rise limit to obtain the braking temperature rise margin. All negative values ​​are set to zero. Under the absorbable level, energy distribution constraints are generated, including bus temporary storage and braking without peak reduction; when the feedback current margin is greater than zero, write "feedback can accept", otherwise write "feedback cannot accept". Under the current shunting level, generate energy allocation constraints that can be temporarily stored on the bus; write feedback can be accepted when the feedback current margin is greater than zero, otherwise write feedback cannot be accepted; write braking can be peak-shaving when the braking temperature rise margin is greater than zero, otherwise write braking does not shaving. Under the suppression level or overvoltage control level, generate energy distribution constraints including those that cannot be temporarily stored on the bus; write feedback can be accepted when the feedback current margin is greater than zero, otherwise write feedback cannot be accepted; write braking can be peak-shaving when the braking temperature rise margin is greater than zero, otherwise write braking without peak-shaving.

7. The method according to claim 6, characterized in that, The bearing capacity is converted according to the following rules: The energy allocation constraint includes that when feedback is available, the feedback current margin is used as the feedback channel's capacity margin; otherwise, it is set to zero. Energy allocation constraints include: when the busbar can be temporarily stored, the busbar protection margin is used as the busbar temporary storage channel capacity; otherwise, it is set to zero. The energy distribution constraint includes using the braking temperature rise margin as the braking channel bearing margin when braking can reduce peak loads; otherwise, it is set to zero.

8. The method according to claim 7, characterized in that, The channel number is determined according to the following rules: When the feedback channel capacity is greater than zero, the feedback channel is written to the first control bit according to the sequence bit mapping; otherwise, it is written to the empty bit. When the capacity of the busbar temporary storage channel is greater than zero, the busbar temporary storage channel is written to the buffer bit; otherwise, it is written to the empty bit. When the braking channel has a carrying capacity greater than zero, the braking channel is written to the peak-shaving position; otherwise, it is written to the empty position. The channel number encoding value is generated by the first connecting position, buffer position, peak-shaving position and empty position.

9. The method according to claim 8, characterized in that, The control word is converted according to the following rules: When the first control bit is written to the feedback channel, the feedback conduction port number is determined according to the port mapping, and the channel bit number encoding value corresponding to the first control bit is written to the port number as the feedback conduction control word. When writing the buffer bit into the bus temporary storage channel, the bus buffer port number is determined according to the port mapping, and the channel bit number encoding value corresponding to the buffer bit is written as the bus buffer control word into the port number. When writing the peak reduction bit into the braking channel, the braking peak reduction port number is determined based on the port mapping, and the channel bit number encoding value corresponding to the peak reduction bit is written into the port number as the braking peak reduction control word; no new conduction permission is generated for the empty bit.

10. The method according to claim 7, characterized in that, The feedback results are generated as follows: The feedback from the execution port includes the feedback current, bus voltage, and braking temperature after execution; The feedback channel feedback result is generated by subtracting the feedback current after execution from the feedback current limit. The difference is set to zero if the difference is less than zero or if the energy allocation constraint includes feedback that cannot be accepted. The bus temporary storage channel feedback result is generated by subtracting the bus voltage after execution from the bus overvoltage boundary. The difference is set to zero if it is less than zero or if the energy distribution constraint includes bus non-temporary storage. The braking channel feedback result is generated by subtracting the braking temperature after execution from the braking temperature rise limit. The difference is less than zero or the energy distribution constraint is set to zero when braking does not reduce peak speed.

Images