Isolation type power drive control panel for hydraulic power electronic control unit

Abstract

The utility model discloses an isolation type power driving control panel for a hydraulic power electronic control unit, which is characterized by comprising a low-edge current detection resistor module, an isolation driving module, an isolation sampling module, an external watchdog module, a voltage monitoring module, a hardware overcurrent protection module and a main control chip, the voltage detection module and the external watchdog are connected with the main control chip, the isolation driving module is connected with the main control chip, the hardware overcurrent protection module is connected with the isolation driving module and the main control chip, and the low-edge current detection resistor module is connected with the isolation sampling module.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic control units, in particular to an isolated power drive control board for a hydraulic power electronic control unit. Background Art

[0002] With the adjustment of my country's energy structure and the acceleration of kinetic energy conversion, the construction machinery industry has experienced new developments, ushering in a golden age for new energy. Compared to construction machinery that relies on fuel, mechanical power, and hydraulic assistance, new energy construction machinery is more environmentally friendly and energy-efficient, and also offers significant advantages in dynamic response.

[0003] There are many ways to transmit torque in new energy engineering machinery that are driven by hydraulics. For example, scissor lift work platforms, electric assisted steering of boom-type aerial vehicles, electro-hydraulic actuators, and variable frequency hydraulic power units can all be carried out in this way. The generation of hydraulic pressure requires a motor to drive it, so the motor control unit is the core component of control and motor drive.

[0004] The primary function of the hydraulic power control unit is to invert DC power into three-phase adjustable AC power, drive the rear-end motor to output torque and speed, and then drive the hydraulic unit to generate pressure, drive the mechanical structure to rise and fall, move forward or backward; at the same time, it also takes into account torque output control, kinetic energy recovery, communication interaction, motor status feedback and protection functions.

[0005] Existing control units use a dual-control chip solution for Hall effect coil current sampling at the midpoint of the bridge arm, which carries the disadvantage of high costs. The control and power sections within the control unit are not isolated. The frequent switching noise and pulse interference from the power section affect the device logic and analog references in the control section, resulting in a decrease in motor control performance. During power unit operation, software errors or transient voltage drops can cause motor control divergence and failure, leading to sudden speed and torque changes. Existing control units have achieved their primary functions, but they still suffer from one or more of the following drawbacks: high cost, lack of safety measures, low reliability, and poor signal quality.

[0006] Therefore, it is necessary to provide an isolated power drive control board for a hydraulic power electronic control unit to solve the above technical problems. Utility Model Content

[0007] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and in the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0008] In order to solve the above technical problems, the utility model provides the following technical solutions: an isolated power drive control board for a hydraulic power electronic control unit, characterized in that it includes a low-side current detection resistor module, an isolation drive module, an isolation sampling module, an external watchdog module, a voltage monitoring module, a hardware overcurrent protection module and a main control chip, the voltage detection module and the external watchdog module are connected to the main control chip, the isolation drive module is connected to the main control chip, the hardware overcurrent protection module is connected to the isolation drive module and the main control chip, and the low-side current detection resistor module is connected to the isolation sampling module.

[0009] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the low-side current sensing resistor module is provided in plurality.

[0010] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the isolated sampling module is also used to collect and monitor the voltage signal source with high output impedance of the power part; thereby realizing dual isolated sampling and monitoring of current and voltage.

[0011] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the isolated drive module receives the drive signal of the control part, drives the three-phase power bridge in the power part after capacitive isolation, electromagnetic isolation or optical isolation, and is combined with the isolated sampling module to form a complete isolation protection to electrically isolate the control and power parts.

[0012] As a preferred solution for the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the hardware overcurrent protection module quickly triggers fault protection through the hardware circuit, and simultaneously inputs it to the hardware trigger interface and isolated drive module of the main chip, so that the fault is input to the main control chip to shut down the output, and the drive circuit can be shut down by hardware at the same time. The dual path protection against faults is safer and more reliable.

[0013] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the present invention: the voltage monitoring module provides circuit initialization and timing monitoring.

[0014] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the external watchdog module is used to monitor the operating status of the main control chip.

[0015] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the utility model: the isolated drive module separates the control part and the power part, and the isolation methods include capacitive isolation, electromagnetic isolation, and optical isolation.

[0016] As a preferred solution of the isolated power drive control board for the hydraulic power electronic control unit described in the present invention: the isolated sampling module separates the output and input of the signal through capacitive isolation technology.

[0017] Beneficial effects of the present invention: The present invention adopts a low-side current detection resistor module and a number of main control chips, making the product solution simpler and more reliable, with a lower probability of hardware failure, thus achieving a low-cost engineering effect;

[0018] The utility model can effectively isolate the pulse noise generated by the power tube when switching on and off in the isolation drive module and the isolation sampling module, and can isolate the high-voltage signal of the power part, so that the signal quality is greatly improved, thereby improving the performance indicators such as control accuracy, response time, and output capacity;

[0019] The utility model improves the reliability and safety redundancy of the product in the hardware overcurrent protection module, external watchdog and voltage monitoring module. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work. Among them:

[0021] Figure 1 This is an operating framework diagram of an isolated power drive control board for a hydraulic power electronic control unit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings in the specification. It is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0023] Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in this field without making any creative work should fall within the scope of protection of the present invention.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Example 1

[0026] Reference Figure 1 An isolated power drive control board for a hydraulic power electronic control unit is characterized by comprising a low-side current-sense resistor module, an isolated driver module, an isolated sampling module, an external watchdog module, a voltage monitoring module, a hardware overcurrent protection module, and a main control chip. The voltage detection module and the external watchdog are connected to the main control chip, the isolated driver module is connected to the main control chip, the hardware overcurrent protection module is connected to the isolated driver module and the main control chip, and the low-side current-sense resistor module is connected to the isolated sampling module. Specifically, the low-side current-sense resistor module, the isolated driver module, the isolated sampling module, the external watchdog module, the voltage monitoring module, and the hardware overcurrent protection module constitute a complete technical solution.

[0027] First, the low-side current-sense resistor module detects current changes through high-precision, low-inductance pure alloy current-sense resistors, reversely infers the different current values ​​passing through, and then detects the current; the number of resistors can be flexibly selected according to the software sampling implementation method, and the number of resistors can be 1, 2, or 3; compared with the Hall coil current sampling at the midpoint of the bridge arm, it has obvious cost advantages.

[0028] Secondly, the isolation drive module separates the control part and the power part. The isolation method can be capacitive isolation, electromagnetic isolation or optical isolation, which can avoid switching pulse interference in power measurement.

[0029] Thirdly, the isolated sampling module can use capacitive isolation technology to separate its output from its input. It is used to monitor the voltage signal source with high output impedance of the power part and to convert the current signal output by the low-side current detection module.

[0030] Fourth, the external watchdog module can monitor the operating status of the main control chip to ensure that in the event of software failure (such as accessing an illegal address) or operation errors, the external reset pin will be enabled to reset the main control chip, so that the main control chip can resume operation. It can also avoid the problem of unsuccessful internal watchdog reset, thereby increasing the redundancy and reliability of product operation safety.

[0031] Fifth, the voltage monitoring module participates in circuit initialization timing control and performs power supply amplitude monitoring. During power-up, when the control unit's power supply voltage exceeds a certain threshold, the reset signal is asserted. Thereafter, the voltage monitor monitors the external power supply and internal power supply of the control unit's main control chip. As long as the power supply voltage falls below a certain threshold, the reset signal remains low to ensure proper system reset.

[0032] Sixth, add a hardware overcurrent protection module to quickly trigger fault protection through the hardware circuit, and simultaneously input it to the hardware trigger interface and isolation drive module of the main chip. It not only inputs the fault to the main control chip to shut down the output, but also can simultaneously shut down the drive circuit by hardware. The dual path protection against faults is safer and more reliable; input to the isolation drive module has a faster response speed and reduces the links of shutting down the output of the main chip.

[0033] Seventh, a main control chip is used, located in the control part, which is responsible for tasks such as signal acquisition, data calculation, logic control, communication control, data storage, and drive signal output; for the power part, there is no main control chip, and it accepts instructions from the main control chip of the control part to perform actions.

[0034] The low offset and drift of this utility model ensure accuracy over the entire temperature range; the high common-mode transient immunity (CMTI) ensures that accurate and reliable measurement results can be provided even in the presence of high-power switches.

[0035] The low-side current-sense resistor module uses Vishay's WSL series products. Utilizing Ohm's law, the module uses high-precision, low-inductance, pure alloy current-sense resistors to reflect changes in the output voltage across the resistors as changes in current. The number of resistors can be one, two, or three. One resistor can sample the total current flowing through the three-phase bridge arms, two resistors can sample the current flowing through any two bridge arms, and three resistors can sample the current flowing through all three bridge arms. By accounting for voltage changes caused by current changes, the module achieves instantaneous, real-time sampling performance. Even with three alloy current-sense resistors, the cost is far lower than a Hall effect coil current sampling solution using the midpoint of a bridge arm.

[0036] Furthermore, the isolated sampling module uses the NOVOSENSE NSI series products and capacitor isolation technology. After receiving the input from the current-sense resistor module, it is filtered, amplified, isolated, and converted into a differential signal to the control end. It then enters the main control chip side and the hardware overcurrent protection module for collection and monitoring. The isolated sampling module is also used to collect and monitor the voltage signal source with high output impedance of the power part, thereby achieving dual-isolation sampling and monitoring of current and voltage. Compared with the direct collection solution of the comparative embodiment, it can prevent pulse interference signals from the power side from entering the control part, greatly improving signal quality, thereby improving performance indicators such as control accuracy, response time, and output capacity.

[0037] Furthermore, the hardware overcurrent protection module uses Texas Instruments series products. After receiving the current signal, it monitors the maximum positive and negative values ​​of the current in real time. If either value reaches the maximum threshold allowed by the protection, the overcurrent protection is triggered, and the output of the isolation driver module is shut down with the highest priority. At the same time, it is sent to the main control chip to inform its product that an overcurrent fault has been triggered. Among them, the response speed of the hardware overcurrent to shut down the isolation driver module with the highest priority is at the single microsecond level, which is far less than the current signal acquisition and conversion speed of the software. In addition, the dual redundant detection function of software monitoring and hardware fast protection is realized. Compared with the existing technology, the utility model has higher reliability and stronger safety redundancy.

[0038] Furthermore, the isolation drive module uses NOVOSENSE NSI series products, which receives the drive signal of the control part, drives the three-phase power bridge in the power part after capacitor isolation, and is combined with the isolation sampling module to form a complete isolation protection to electrically isolate the control and power parts; compared with the non-isolated drive module in the comparative embodiment, it can effectively isolate the pulse noise generated by the power tube during switching, and can isolate the high-voltage signal of the power part, thereby playing an electrical isolation role.

[0039] Furthermore, the main control chip uses the Renesa RH850 series product. Although it uses one chip, it has a dual-core processor. One core works normally as the main processor, and the other core works as a check processor to monitor the operation of the main processor. The two processors work in lock-step mode. The two main control chips in the existing technology respectively perform control communication functions and three-phase bridge drive functions. Compared with the two main chips in the existing technology, the probability of hardware failure is lower, and the product solution is simpler and more reliable.

[0040] Furthermore, the external watchdog module, a Texas Instruments product, monitors the main chip's operation through an independent external chip. Correctly answering questions from the independent hardware monitoring unit within a set time window triggers a controller reset or safe state if the system times out or responds incorrectly a certain number of times. Compared to existing technologies, this new system enhances system reliability by adding independent hardware monitoring of the main chip.

[0041] Furthermore, the voltage monitoring module uses Texas Instruments products, which diagnose overvoltage, undervoltage, and fluctuations in the power supply of the main chip and safety-related sensors. It sets overvoltage and undervoltage thresholds respectively, and triggers the main control chip in time when a fault is identified, reporting the fault and taking fault protection action. Compared with existing technologies, the addition of independent voltage monitoring improves system reliability.

[0042] In summary, the technical solution of the utility model is simpler and more reliable, has a lower probability of hardware failure, higher reliability, and stronger safety redundancy, achieving a low-cost engineering effect; and improving performance indicators such as control accuracy, response time, and output capacity.

[0043] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0044] It will be appreciated that in the development of any actual embodiment, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will, for those of ordinary skill having the benefit of this disclosure, be a routine undertaking of design, fabrication, and production without undue experimentation.

[0045] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the claims of the present invention.

Claims

1. An isolated power drive control board for a hydraulic power electronic control unit, characterized by: It includes a low-side current-sense resistor module, an isolation drive module, an isolation sampling module, an external watchdog module, a voltage monitoring module, a hardware overcurrent protection module and a main control chip. The voltage detection module and the external watchdog module are connected to the main control chip, the isolation drive module is connected to the main control chip, the hardware overcurrent protection module is connected to the isolation drive module and the main control chip, and the low-side current-sense resistor module is connected to the isolation sampling module.

2. The isolated power drive control board for the hydraulic power electronic control unit according to claim 1, characterized in that: The low-side current-sense resistor modules are provided in plurality.

3. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The isolated sampling module is also used to collect and monitor the voltage signal source with high output impedance of the power part, thereby realizing dual isolated sampling and monitoring of current and voltage.

4. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The isolation drive module receives the drive signal of the control part, drives the three-phase power bridge in the power part after capacitive isolation, electromagnetic isolation or optical isolation, and is combined with the isolation sampling module to form isolation protection to electrically isolate the control and power parts.

5. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The hardware overcurrent protection module quickly triggers fault protection through the hardware circuit and simultaneously inputs it to the hardware trigger interface and isolation drive module of the main chip. It not only inputs the fault to the main control chip to shut down the output, but also can simultaneously shut down the drive circuit by hardware. The dual path protection against faults is safer and more reliable.

6. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The voltage monitoring module provides circuit initialization and timing monitoring.

7. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The external watchdog module is used to monitor the operating status of the main control chip.

8. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The isolation drive module separates the control part from the power part, and the isolation methods include capacitive isolation, electromagnetic isolation and optical isolation.

9. The isolated power drive control board for a hydraulic power electronic control unit according to claim 1, characterized in that: The isolated sampling module separates the output and input of the signal through capacitive isolation technology.

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