A multi-in-one drive frequency converter capable of driving multiple spindle motors

Abstract

The application relates to a multi-in-one drive frequency converter capable of driving multiple spindle motors, two groups of three-phase inverter bridges independently controlled by double DSPs are integrated in a single frequency converter, and two-way output is flexibly switched to five spindle motors through five interlocking relay matrices, so that only two motors work in parallel at any moment, and the rest of the motors are in zero-power standby; the application reduces one-to-one driving of five spindle motors in a traditional multi-process system to one frequency converter, greatly reduces manufacturing and maintenance costs and reduces the size of the frequency converter, eliminates invalid power consumption of standby frequency converters, and reduces overall system power consumption; in addition, the hardware interlocking mechanism fundamentally avoids the risk of short circuit of two-way inverter bridge output, and simplification of wiring complexity greatly improves production and assembly efficiency, and provides a high-integration, high-performance-price-ratio and safe and reliable driving control solution for the industry.

Description

Technical Field

[0001] This invention relates to the field of industrial motor control technology, and in particular to a multi-in-one drive frequency converter that can drive multiple spindle motors. Background Technology

[0002] In the field of woodworking machinery, multi-process woodworking engraving machines and cutting machines are widely used. They can efficiently complete various engraving and cutting processes such as grooving, drilling, cutting, edge guiding, and milling. They are indispensable equipment in modern woodworking production. In traditional multi-process woodworking engraving machines or cutting machines, the spindle motor drive control usually adopts a one-to-one frequency converter drive method, which requires multiple frequency converters to drive the corresponding spindle motors independently. For example, in a typical five-process engraving machine system, five spindle motors are responsible for different processes such as grooving, drilling, and cutting, which require five independent frequency converters for drive. This traditional method has many shortcomings: (1) The cumulative purchase cost of multiple frequency converters is high, and at the same time, due to Each inverter input terminal needs to be equipped with an independent circuit breaker (K1-K5) for control, increasing the amount of electrical components such as circuit breakers and contactors, further increasing the raw material costs for the cabinet manufacturer; (2) Five inverters and corresponding supporting facilities occupy a large cabinet space, making the cabinet bulky and not conducive to the overall layout and space optimization of the equipment; (3) Each inverter needs to be wired separately, resulting in a high degree of complexity in the wiring inside the cabinet, which not only increases the time and labor cost of cabinet assembly, but may also reduce the reliability of the system due to wiring errors; (4) At the same time, usually only two spindle motors are in working state, while the other three inverters are in standby state, but the standby inverters will still consume a certain amount of power, resulting in energy waste. Summary of the Invention

[0003] In view of this, the present invention provides an all-in-one drive frequency converter that can drive multiple spindle motors, solving the technical problems of high cost, large space occupation, complicated wiring and high energy consumption of traditional multi-spindle motor drive systems, realizing the driving of multiple spindle motors by a single device, thereby reducing system cost and improving the overall performance of the system.

[0004] To achieve the above objectives, the present invention provides an all-in-one drive frequency converter capable of driving multiple spindle motors. The all-in-one drive frequency converter includes dual digital signal processing control (DSP) modules, two independent three-phase inverter bridge circuits, and two sets of relay matrices.

[0005] The two independent three-phase inverter bridge circuits include the first three-phase inverter bridge circuit INV-1 and the second three-phase inverter bridge circuit INV-2;

[0006] The dual digital signal processing control (DSP) module includes a first signal processor (DSP1) and a second signal processor (DSP2).

[0007] The two sets of relay matrices are relay matrix A and relay matrix B, respectively. Relay matrix A includes five sets of relays T1-A, T2-A, T3-A, T4-A, and T5-A, which control the U1, V1, and W1 phases of the spindle motors M1-M5, respectively. Relay matrix B includes five sets of relays T1-B, T2-B, T3-B, T4-B, and T5-B, which control the U2, V2, and W2 phases of the spindle motors M1-M5, respectively.

[0008] The PWM output pin of the first signal processor DSP1 is connected to the driver chip of the IGBT module of the first three-phase inverter bridge circuit INV-1 through an optocoupler isolation circuit, and the PWM output pin of the second signal processor DSP2 is connected to the driver chip of the IGBT module of the second three-phase inverter bridge circuit INV-2 through an optocoupler isolation circuit.

[0009] The output three-phase lines U1, V1, and W1 of the first three-phase inverter bridge circuit INV-1 are connected to relay matrix A, and the output three-phase lines U2, V2, and W2 of the second three-phase inverter bridge circuit INV-2 are connected to relay matrix B.

[0010] The relay matrix A includes five sets of relays: T1-A, T2-A, T3-A, T4-A, and T5-A. The relay matrix B includes five sets of relays: T1-B, T2-B, T3-B, T4-B, and T5-B. Relays T1-A and T1-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M1. Relays T2-A and T2-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M2. Relays T3-A and T3-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M3. Relays T4-A and T4-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M4. Relays T5-A and T5-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M5.

[0011] Preferably, the first three-phase inverter bridge circuit INV-1 includes six IGBT modules: a first IGBT module Q1, a second IGBT module Q2, a third IGBT module Q3, a fourth IGBT module Q4, a fifth IGBT module Q5, and a sixth IGBT module Q6, wherein the first IGBT module Q1, the second IGBT module Q2, the third IGBT module Q3, the fourth IGBT module Q4, the fifth IGBT module Q5, and the sixth IGBT module Q6 are connected in parallel.

[0012] The second three-phase inverter bridge circuit INV-2 includes six IGBT modules: the seventh IGBT module Q7, the eighth IGBT module Q8, the ninth IGBT module Q9, the tenth IGBT module Q10, the eleventh IGBT module Q11, and the twelfth IGBT module Q12, which are connected in parallel.

[0013] Preferably, the first signal processor DSP1 controls the drive signal of the IGBT module of the first three-phase inverter bridge circuit INV-1, and samples the output current and output voltage of the first three-phase inverter bridge circuit INV-1.

[0014] The second signal processor DSP2 controls the drive signal of the IGBT module of the second three-phase inverter bridge circuit INV-2, and samples the output current and output voltage of the second three-phase inverter bridge circuit INV-2.

[0015] Preferably, the first signal processor DSP1 and the second signal processor DSP2 communicate via CAN to coordinate the relay switching timing.

[0016] Preferably, the motors M1, M2, M3, M4 and M5 are only allowed to be connected to one three-phase inverter bridge circuit output.

[0017] Preferably, the control circuits of the two relay coils corresponding to the same motor are connected in series with normally closed contacts. That is: for relays T1-A and T1-B connected to motor M1, when relay T1-A is energized, the control circuit of relay T1-B is automatically disconnected; for relays T2-A and T2-B connected to motor M2, when relay T2-A is energized, the control circuit of relay T2-B is automatically disconnected; for relays T3-A and T3-B connected to motor M3, when relay T3-A is energized, the control circuit of relay T3-B is automatically disconnected; for relays T4-A and T4-B connected to motor M4, when relay T4-A is energized, the control circuit of relay T4-B is automatically disconnected; for relays T5-A and T5-B connected to motor M5, when relay T5-A is energized, the control circuit of relay T5-B is automatically disconnected.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention utilizes internal dual inverter bridges and relay interlocking switching, with dual DSP control driving two three-phase inverter bridges to output two independent three-phase frequency-converted AC power supplies. By controlling five sets of relays for output switching, it achieves the effect of simultaneously driving two different spindle motors. This allows a maximum of two spindle motors to receive independent power at the same time, while the remaining motors are in standby mode without consuming standby power. The five spindle drive tasks that originally required five frequency converters are integrated into a single multi-functional frequency converter. This results in simultaneous reductions in six dimensions: hardware quantity, cabinet size, wiring length, number of circuit breakers / contactors, assembly time, and standby power consumption. This reduces the manufacturer's overall raw material and labor costs, as well as the end-user's operating electricity costs and maintenance complexity, creating a disruptive cost reduction, efficiency improvement, and energy-saving effect in the industry. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the circuit topology of the all-in-one frequency converter of the present invention;

[0021] Figure 2 This is the electrical schematic diagram of the multi-in-one frequency converter of the present invention;

[0022] Figure 3 This is a schematic diagram of the inverter system structure of a traditional five-process engraving machine system. Detailed Implementation

[0023] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0024] Example 1

[0025] This embodiment provides a multi-in-one drive frequency converter that can drive multiple spindle motors. The multi-in-one drive frequency converter includes dual digital signal processing control (DSP) modules, two independent three-phase inverter bridge circuits, and two sets of relay matrices.

[0026] The two independent three-phase inverter bridge circuits include the first three-phase inverter bridge circuit INV-1 and the second three-phase inverter bridge circuit INV-2;

[0027] The dual digital signal processing control (DSP) module includes a first signal processor DSP1 and a second signal processor DSP2;

[0028] The two sets of relay matrices are relay matrix A and relay matrix B, respectively.

[0029] Relay matrix A includes five sets of relays T1-A, T2-A, T3-A, T4-A, and T5-A, which control the U1, V1, and W1 phases of spindle motors M1-M5 respectively. Relay matrix B includes five sets of relays T1-B, T2-B, T3-B, T4-B, and T5-B, which control the U2, V2, and W2 phases of spindle motors M1-M5 respectively. Each set of relays includes interlocking contacts.

[0030] Three-phase AC power supplies L1, L2, and L3 are rectified and filtered to form a DC bus. The DC bus is stepped down by a switching power supply module to power the first signal processor DSP1 and the first signal processor DSP2.

[0031] The PWM output pin of the first signal processor DSP1 is connected to the driver chip of the IGBT module of the first three-phase inverter bridge circuit INV-1 through an optocoupler isolation circuit, controlling the drive signal of the IGBT module of the first three-phase inverter bridge circuit INV-1, and sampling the output current and output voltage of the first three-phase inverter bridge circuit INV-1; the PWM output pin of the second signal processor DSP2 is connected to the driver chip of the IGBT module of the second three-phase inverter bridge circuit INV-2 through an optocoupler isolation circuit, controlling the drive signal of the IGBT module of the second three-phase inverter bridge circuit INV-2, and sampling the output current and output voltage of the second three-phase inverter bridge circuit INV-2; the first signal processor DSP1 and the second signal processor DSP2 communicate via CAN to coordinate the relay switching timing;

[0032] The output three-phase lines U1, V1, and W1 of the first three-phase inverter bridge circuit INV-1 are connected to relay matrix A, and the output three-phase lines U2, V2, and W2 of the second three-phase inverter bridge circuit INV-2 are connected to relay matrix B. The first three-phase inverter bridge circuit INV-1 includes 6 IGBT modules: first IGBT module Q1, second IGBT module Q2, third IGBT module Q3, fourth IGBT module Q4, fifth IGBT module Q5, and sixth IGBT module Q6. The first IGBT module Q1, second IGBT module Q2, third IGBT module Q3, fourth IGBT module Q4, fifth IGBT module Q5, and sixth IGBT module Q6 are connected in parallel.

[0033] The second three-phase inverter bridge circuit INV-2 includes six IGBT modules: the seventh IGBT module Q7, the eighth IGBT module Q8, the ninth IGBT module Q9, the tenth IGBT module Q10, the eleventh IGBT module Q11, and the twelfth IGBT module Q12. The seventh IGBT module Q7, the eighth IGBT module Q8, the ninth IGBT module Q9, the tenth IGBT module Q10, the eleventh IGBT module Q11, and the twelfth IGBT module Q12 are connected in parallel.

[0034] Relay matrix A includes five relay groups: T1-A, T2-A, T3-A, T4-A, and T5-A; relay matrix B includes five relay groups: T1-B, T2-B, T3-B, T4-B, and T5-B. The three-phase lines U1, V1, and W1 of the first three-phase inverter bridge circuit INV-1 are connected to the common contact terminals of T1-A, T2-A, T3-A, T4-A, and T5-A, respectively. The three-phase lines U2, V2, and W2 of the second three-phase inverter bridge circuit INV-2 are connected to the common contact terminals of T1-B, T2-B, T3-B, T4-B, and T5-B, respectively. Relays T1-A and T1-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M1. Relays T2-A and T2-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M2. Relays T3-A and T3-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M3. Relays T4-A and T4-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M4. Relays T5-A and T5-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M5.

[0035] Motors M1, M2, M3, M4, and M5 are only allowed to be connected to one three-phase inverter bridge circuit output. The two relay coil control circuits corresponding to the same motor are connected in series with normally closed contacts. That is, for relays T1-A and T1-B connected to motor M1, the power supply circuit of relay T1-A is connected in series with the normally closed contact of relay T1-B, and the power supply circuit of relay T1-B is connected in series with the normally closed contact of relay T1-A. When relay T1-A is energized, the control circuit of relay T1-B is automatically disconnected, forming a physical interlock. The four sets of structures of relays T2-A and T2-B, T3-A and T3-B, T4-A and T4-B, and T5-A and T5-B are the same as those of relays T1-A and T1-B.

[0036] Example 2

[0037] In practical applications of woodworking engraving machines or panel saws, taking a five-process system as an example, this system includes five spindle motors, each responsible for different engraving or panel sawing processes; the multi-in-one drive inverter provided in this embodiment operates according to the following steps:

[0038] S1. Based on the pre-set engraving or cutting task program, determine the two spindle motors that need to work at the same time and their corresponding process parameters, such as speed and torque requirements.

[0039] S2. The dual DSP control module inside the inverter controls and adjusts the two independent three-phase inverter bridges according to the process parameters, generating two independent three-phase frequency conversion AC power supplies to provide suitable power for the two spindle motors that are about to start working.

[0040] S3. By controlling the on / off state of the relay group, two three-phase frequency conversion AC power outputs are sent to the corresponding two spindle motors to start their operation and complete the corresponding engraving or cutting process.

[0041] For example, at a certain moment, control relays T1 and T2 are closed, so that the AC power output from the first three-phase inverter bridge circuit drives the No. 1 spindle motor to perform trenching work, while the AC power output from the second three-phase inverter bridge drives the No. 2 spindle motor to perform drilling work through relay T2.

[0042] S4. When a process switch is required, such as switching from trenching and drilling to cutting and edge guiding, the control system issues a corresponding command to close relay groups T3 and T4, while simultaneously opening relays T1 and T2, thereby switching the output of the frequency converter to spindle motors No. 3 and No. 4, which are then powered by the two inverter bridges to enable the cutting and edge guiding process.

[0043] During this process, the interlock control mechanism ensures that two inverter bridges will not simultaneously output to the same spindle motor during the switching process, thus guaranteeing the safety of the system.

[0044] S5. For the fifth spindle motor in the five-process system (e.g., motor No. 5 responsible for milling), when it needs to work, the power is supplied by one of the inverter bridges through the on / off control of relay group T5 to complete the milling process.

[0045] Since only a maximum of two spindle motors can operate at any given time, the frequency converter can flexibly switch and drive between different spindle motors to meet the working requirements of the five-process system.

[0046] Through actual production application and testing, the all-in-one drive frequency converter provided in this embodiment has achieved good application results in the woodworking panel saw industry. It has effectively improved the production and assembly efficiency of woodworking panel saw system integrators, reduced raw material costs and manufacturing costs, and provided end users with more energy-efficient, efficient and easy-to-operate woodworking equipment. It has broad market application prospects and significant economic benefits.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A multi-function drive inverter capable of driving multiple spindle motors, characterized in that, The all-in-one drive frequency converter includes dual digital signal processing control DSP modules, two independent three-phase inverter bridge circuits, and two sets of relay matrices. The two independent three-phase inverter bridge circuits include the first three-phase inverter bridge circuit INV-1 and the second three-phase inverter bridge circuit INV-2; The dual digital signal processing control (DSP) module includes a first signal processor (DSP1) and a second signal processor (DSP2). The two sets of relay matrices are relay matrix A and relay matrix B, respectively. Relay matrix A includes five sets of relays T1-A, T2-A, T3-A, T4-A, and T5-A, which control the U1, V1, and W1 phases of the spindle motors M1-M5, respectively. Relay matrix B includes five sets of relays T1-B, T2-B, T3-B, T4-B, and T5-B, which control the U2, V2, and W2 phases of the spindle motors M1-M5, respectively. The PWM output pin of the first signal processor DSP1 is connected to the driver chip of the IGBT module of the first three-phase inverter bridge circuit INV-1 through an optocoupler isolation circuit, and the PWM output pin of the second signal processor DSP2 is connected to the driver chip of the IGBT module of the second three-phase inverter bridge circuit INV-2 through an optocoupler isolation circuit. The output three-phase lines U1, V1, and W1 of the first three-phase inverter bridge circuit INV-1 are connected to relay matrix A, and the output three-phase lines U2, V2, and W2 of the second three-phase inverter bridge circuit INV-2 are connected to relay matrix B. The relay matrix A includes five sets of relays: T1-A, T2-A, T3-A, T4-A, and T5-A. The relay matrix B includes five sets of relays: T1-B, T2-B, T3-B, T4-B, and T5-B. Relays T1-A and T1-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M1. Relays T2-A and T2-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M2. Relays T3-A and T3-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M3. Relays T4-A and T4-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M4. Relays T5-A and T5-B are connected in parallel via normally open contacts and then connected to the U, V, and W terminals of motor M5.

2. The multi-in-one drive frequency converter capable of driving multiple spindle motors according to claim 1, characterized in that, The first three-phase inverter bridge circuit INV-1 includes six IGBT modules: first IGBT module Q1, second IGBT module Q2, third IGBT module Q3, fourth IGBT module Q4, fifth IGBT module Q5, and sixth IGBT module Q6. The first IGBT module Q1, second IGBT module Q2, third IGBT module Q3, fourth IGBT module Q4, fifth IGBT module Q5, and sixth IGBT module Q6 are connected in parallel. The second three-phase inverter bridge circuit INV-2 includes six IGBT modules: the seventh IGBT module Q7, the eighth IGBT module Q8, the ninth IGBT module Q9, the tenth IGBT module Q10, the eleventh IGBT module Q11, and the twelfth IGBT module Q12, which are connected in parallel.

3. The multi-in-one drive frequency converter capable of driving multiple spindle motors according to claim 1, characterized in that, The first signal processor DSP1 controls the drive signal of the IGBT module of the first three-phase inverter bridge circuit INV-1, and samples the output current and output voltage of the first three-phase inverter bridge circuit INV-1. The second signal processor DSP2 controls the drive signal of the IGBT module of the second three-phase inverter bridge circuit INV-2, and samples the output current and output voltage of the second three-phase inverter bridge circuit INV-2.

4. The multi-in-one drive frequency converter capable of driving multiple spindle motors according to claim 3, characterized in that, The first signal processor DSP1 and the second signal processor DSP2 communicate via CAN to coordinate the relay switching timing.

5. A multi-in-one drive frequency converter capable of driving multiple spindle motors according to claim 1, characterized in that, The motors M1, M2, M3, M4, and M5 are only allowed to be connected to one three-phase inverter bridge circuit output.

6. A multi-in-one drive frequency converter capable of driving multiple spindle motors according to claim 5, characterized in that, The control circuits of the two relay coils corresponding to the same motor are connected in series with normally closed contacts. Specifically: for relays T1-A and T1-B connected to motor M1, when relay T1-A is energized, the control circuit of relay T1-B is automatically disconnected; for relays T2-A and T2-B connected to motor M2, when relay T2-A is energized, the control circuit of relay T2-B is automatically disconnected; for relays T3-A and T3-B connected to motor M3, when relay T3-A is energized, the control circuit of relay T3-B is automatically disconnected; for relays T4-A and T4-B connected to motor M4, when relay T4-A is energized, the control circuit of relay T4-B is automatically disconnected; and for relays T5-A and T5-B connected to motor M5, when relay T5-A is energized, the control circuit of relay T5-B is automatically disconnected.

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