Frequency conversion electric control system and electronic equipment

Abstract

The utility model discloses a variable-frequency electric control system and electronic equipment, and belongs to the technical field of variable-frequency driving. The frequency conversion electric control system comprises a main power module, an auxiliary power supply module, a transistor driving module and a main control module, the main power module is electrically connected with the input source, the auxiliary power module, the transistor driving module and the motor; the auxiliary power supply module is electrically connected with the transistor driving module and the main control module, and the auxiliary power supply module is used for taking power from a direct current bus of the main power module and supplying power to the transistor driving module and the main control module; and the transistor driving module is electrically connected with the main control module and is used for driving the on-off of each transistor in the main power module under the control of the main control module. According to the invention, the design cost, complexity and occupied space of the frequency conversion all-in-one machine product are reduced.

Description

Technical Field

[0001] The present application relates to the field of variable frequency drive technology, and in particular to variable frequency electric control systems and electronic equipment. Background Art

[0002] At present, in industrial application fields such as coal mines, ports, and metallurgy, the market has an increasing demand for miniaturized inverter products, high cost performance, and single-machine power, so all-in-one inverters came into being.

[0003] However, the frequency converter products currently available on the market either use a common two-level topology, which has high cost, complex driving technology, and IGBT modules that occupy a large module space, or use an NPC (Neutral Point Clamped) three-level topology, which has a complex topology and structural space layout, and also requires a transformer to use, further increasing the occupied space. Utility Model Content

[0004] The main purpose of this application is to provide a variable frequency electric control system and electronic equipment, aiming to reduce the design cost, complexity and occupied space of the variable frequency all-in-one product.

[0005] To achieve the above-mentioned purpose, the present application provides a variable frequency electric control system, which comprises: a main power module, an auxiliary power module, a transistor drive module and a main control module;

[0006] The main power module is electrically connected to an input source, the auxiliary power module, the transistor drive module and the motor;

[0007] The auxiliary power supply module is electrically connected to the transistor driving module and the main control module, and the auxiliary power supply module is used to draw power from the DC bus of the main power module and supply power to the transistor driving module and the main control module;

[0008] The transistor driving module is electrically connected to the main control module, and is used to drive the on and off of each transistor in the main power module under the control of the main control module.

[0009] In one embodiment, the main power module includes: a three-phase uncontrolled rectifier circuit, a DC bus pre-charging circuit, a DC filter circuit and a three-phase full-bridge inverter circuit;

[0010] The three-phase uncontrolled rectifier circuit is electrically connected to the input source, the DC bus pre-charging circuit, the DC filter circuit and the three-phase full-bridge inverter circuit;

[0011] The DC bus pre-charging circuit is electrically connected to the auxiliary power supply module and the DC filter circuit;

[0012] The DC filter circuit is electrically connected to the three-phase full-bridge inverter circuit;

[0013] The three-phase full-bridge inverter circuit is electrically connected to the transistor drive module and the motor.

[0014] In one embodiment, the three-phase uncontrolled rectifier circuit includes: a first diode, a second diode, a third diode, a fourth diode, a fifth diode and a sixth diode;

[0015] The first diode and the fourth diode are connected in series to form a first diode half-bridge unit, and a midpoint of a bridge arm of the first diode half-bridge unit is electrically connected to a first phase of the input source;

[0016] The second diode and the fifth diode are connected in series to form a second diode half-bridge unit, and the midpoint of the bridge arm of the second diode half-bridge unit is connected to the second phase of the input source;

[0017] The third diode and the sixth diode are connected in series to form a third diode half-bridge unit, and the midpoint of the bridge arm of the third diode half-bridge unit is connected to the third phase of the input source;

[0018] The first end of the first diode half-bridge unit, the first end of the second diode half-bridge unit and the first end of the third diode half-bridge unit are electrically connected to the first end of the DC bus pre-charging circuit;

[0019] The second end of the first diode half-bridge unit, the second end of the second diode half-bridge unit and the second end of the third diode half-bridge unit are electrically connected to the second end of the DC filter circuit and the second end of the three-phase full-bridge inverter circuit.

[0020] In one embodiment, the DC bus pre-charging circuit includes: a pre-charging resistor, a first thyristor and a second thyristor;

[0021] The first end of the pre-charging resistor, the anode of the first thyristor and the anode of the second thyristor are electrically connected to the first end of the three-phase uncontrolled rectifier circuit;

[0022] The second end of the pre-charging resistor, the cathode of the first thyristor and the cathode of the second thyristor are electrically connected to the first end of the DC filter circuit;

[0023] The gate of the first thyristor and the gate of the second thyristor are electrically connected to the auxiliary power supply module.

[0024] In one embodiment, the DC filter circuit includes: a DC reactor, a first capacitor and a second capacitor;

[0025] The first end of the DC reactor is electrically connected to the second end of the DC bus pre-charging circuit;

[0026] The second end of the DC reactor and the first end of the first capacitor are electrically connected to the first end of the three-phase full-bridge inverter circuit;

[0027] The second end of the first capacitor and the first end of the second capacitor are electrically connected to the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit;

[0028] The second end of the second capacitor is electrically connected to the second end of the three-phase uncontrolled rectifier circuit and the second end of the three-phase full-bridge inverter circuit.

[0029] In one embodiment, the variable frequency electric control system further includes: a voltage-sharing discharge circuit, the voltage-sharing discharge circuit being electrically connected to the three-phase uncontrolled rectifier circuit, the DC filter circuit and the three-phase full-bridge inverter circuit;

[0030] The voltage-balanced discharge circuit comprises: a first resistor and a second resistor;

[0031] The first end of the first resistor is electrically connected to the second end of the DC reactor, the first end of the first capacitor and the first end of the three-phase full-bridge inverter circuit;

[0032] The second end of the first resistor and the first end of the second resistor are electrically connected to the second end of the first capacitor, the first end of the second capacitor and the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit;

[0033] The second end of the second resistor is electrically connected to the second end of the three-phase uncontrolled rectifier circuit, the second end of the DC filter circuit and the second end of the three-phase full-bridge inverter circuit.

[0034] In one embodiment, the motor includes a first motor and a second motor; the three-phase full-bridge inverter circuit includes: a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor and a twelfth transistor, and the controlled end of each of the transistors is electrically connected to the transistor driving module;

[0035] The first transistor and the second transistor are connected in series to form a first upper half bridge, the third transistor and the fourth transistor are connected in series to form a first lower half bridge, the fifth transistor and the sixth transistor are connected in series to form a second upper half bridge, the seventh transistor and the eighth transistor are connected in series to form a second lower half bridge, the ninth transistor and the tenth transistor are connected in series to form a third upper half bridge, and the eleventh transistor and the twelfth transistor are connected in series to form a third lower half bridge;

[0036] The first end of the first upper half bridge, the first end of the second upper half bridge and the first end of the third upper half bridge are electrically connected to the second end of the DC reactor and the first end of the first capacitor; the second end of the first upper half bridge, the second end of the second upper half bridge, the second end of the third upper half bridge, the first end of the first lower half bridge, the first end of the second lower half bridge and the first end of the third lower half bridge together constitute the midpoint of the three-phase bridge arm; the midpoint of the three-phase bridge arm is electrically connected to the second end of the first capacitor and the first end of the second capacitor; the second end of the first lower half bridge, the second end of the second lower half bridge and the second end of the third lower half bridge are electrically connected to the second end of the three-phase uncontrolled rectifier circuit and the second end of the DC filter circuit;

[0037] The midpoint of the bridge arm of the first upper half bridge, the midpoint of the bridge arm of the second upper half bridge and the midpoint of the bridge arm of the third upper half bridge are respectively electrically connected to the three-phase input end of the first motor, and the midpoint of the bridge arm of the first lower half bridge, the midpoint of the bridge arm of the second lower half bridge and the midpoint of the bridge arm of the third lower half bridge are respectively electrically connected to the three-phase input end of the second motor.

[0038] In one embodiment, the auxiliary power supply module includes: a single-channel output power supply circuit, a multi-channel output power supply circuit, a first step-down circuit, a linear voltage regulator circuit, a second step-down circuit and a pulse signal forward switching power supply circuit;

[0039] The input end of the single-channel output power supply circuit is electrically connected to the DC bus of the main power module, and the single-channel output power supply circuit is used to draw power from the DC bus of the main power module to output a first DC voltage;

[0040] The input end of the multi-channel output power supply circuit is electrically connected to the output end of the single-channel output power supply circuit, and the multi-channel output power supply circuit is used to output the first DC voltage, the second DC voltage and the third DC voltage;

[0041] The input end of the first step-down circuit is electrically connected to the output end of the multi-output power supply circuit, and the first step-down circuit is used to step down the third DC voltage to output a fourth DC voltage;

[0042] The input end of the linear voltage stabilizing circuit is electrically connected to the output end of the first step-down circuit, the output end of the linear voltage stabilizing circuit is electrically connected to the main control module, and the linear voltage stabilizing circuit is used to convert the fourth DC voltage into a fifth DC voltage to supply power to the main control module;

[0043] The input end of the second step-down circuit is electrically connected to the output end of the single-channel output power supply circuit, and the second step-down circuit is used to step down the first DC voltage to output a sixth DC voltage;

[0044] The input end of the pulse signal forward switching power supply circuit is electrically connected to the output end of the second step-down circuit, the output end of the pulse signal forward switching power supply circuit is electrically connected to the DC bus pre-charging circuit of the main power module, and the enable end of the pulse signal forward switching power supply circuit is electrically connected to the main control module.

[0045] In one embodiment, the transistor driving module includes: a PWM interlocking amplifier circuit, a fault feedback circuit, a forward transformer, and an optocoupler driving unit;

[0046] The input end of the PWM interlock amplifier circuit is electrically connected to the main control module, and the output end of the PWM interlock amplifier circuit is electrically connected to the optical coupler drive unit through an optical fiber, and the PWM interlock amplifier circuit is used to send a PWM wave to the optical coupler drive unit;

[0047] The input end of the fault feedback circuit is electrically connected to the optical coupler drive unit, the output end of the fault feedback circuit is electrically connected to the main control module, and the fault feedback circuit is used to detect abnormalities and short circuit faults of the driving power supply;

[0048] The input end of the forward transformer is electrically connected to the auxiliary power supply module, the output end of the forward transformer is electrically connected to the optocoupler drive unit, and the forward transformer is used to supply power to the optocoupler drive unit;

[0049] The optocoupler driving unit is electrically connected to the transistor in the main power module, and the optocoupler driving unit is used to drive the transistor according to the PWM wave.

[0050] In addition, to achieve the above-mentioned purpose, the present application also provides an electronic device, which includes the variable frequency electric control system as described above.

[0051] The present application proposes a variable frequency electric control system and electronic equipment, which overcomes the problems of high cost, high complexity and large space occupied by the variable frequency integrated machine products in the related technology. The variable frequency electric control system includes: a main power module, an auxiliary power module, a transistor drive module and a main control module; the main power module is electrically connected to the input source, the auxiliary power module, the transistor drive module and the motor; the auxiliary power module is electrically connected to the transistor drive module and the main control module, and the auxiliary power module is used to take power from the DC bus of the main power module and supply power to the transistor drive module and the main control module; the transistor drive module is electrically connected to the main control module, and the transistor drive module is used to drive the on and off of each transistor in the main power module under the control of the main control module. In the variable frequency electric control system provided by the present application, the circuit topology and structural layout of the main power module are simplified, which can significantly reduce the size of the whole machine, occupy less structural space, drive more simply, and greatly save costs; by designing the auxiliary power module to directly take power from the high-voltage DC bus of the main power module, and then supply power to the transistor drive module and the main control module, the power supply efficiency can be greatly improved, and the traditional transformer can be omitted, so as to achieve the purpose of saving space and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0053] Figure 1 A schematic diagram of the structure of a variable frequency electric control system provided in an embodiment of the present application;

[0054] Figure 2 A schematic diagram of the structure of a main power module in a variable frequency electric control system provided in an embodiment of the present application;

[0055] Figure 3 Another structural schematic diagram of a main power module in a variable frequency electric control system provided in an embodiment of the present application;

[0056] Figure 4 A detailed structural diagram of a main power module in a variable frequency electric control system provided in an embodiment of the present application;

[0057] Figure 5 A schematic diagram of the structure of an auxiliary power supply module in a variable frequency electric control system provided in an embodiment of the present application;

[0058] Figure 6 A schematic diagram of the structure of a transistor drive module in a variable frequency electric control system provided in an embodiment of the present application;

[0059] Figure 7 A schematic diagram of the structure of a main control module in a variable frequency electric control system provided in an embodiment of the present application.

[0060] Description of the accompanying drawings: 10, main power module; 20, auxiliary power module; 30, transistor drive module; 40, main control module; 101, three-phase uncontrolled rectifier circuit; 102, DC bus pre-charging circuit; 103, DC filter circuit; 104, three-phase full-bridge inverter circuit; 105, voltage-balanced discharge circuit; 106, current sensor; D1~D6, first to sixth diodes; R, first phase of input source; S, second phase of input source; T, third phase of input source; RP1, pre-charging resistor; SCR1, first thyristor; SCR2, second thyristor; L1 , DC reactor; C1, first capacitor; C2, second capacitor; R1, first resistor; R2, second resistor; MR1, first motor; MR2, second motor; S1~S12, first to twelfth transistors; 201, single-channel output power supply circuit; 202, multi-channel output power supply circuit; 203, first step-down circuit; 204, linear voltage regulator circuit; 205, second step-down circuit; 206, pulse signal forward switching power supply circuit; 301, PWM interlock amplifier circuit; 302, fault feedback circuit; 303, forward transformer; PC, optocoupler drive unit.

[0061] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0063] At present, in industrial application fields such as coal mines, ports, and metallurgy, the market has an increasing demand for miniaturized inverter products, high cost performance, and single-machine power, resulting in the emergence of all-in-one inverters, which are particularly suitable for small space applications underground in coal mines.

[0064] However, the 1140V all-in-one inverter products currently on the market either adopt a general two-level topology and use a 3300V withstand voltage IGBT (Insulate-Gate Bipolar Transistor) module, which has the disadvantages of high cost, high heat loss, complex driving technology, and large space occupation; or use an NPC three-level topology, which has the disadvantages of complex topology, high cost, difficult busbar design, and large structural space occupation; at the same time, these all-in-one inverter products also need to be equipped with a transformer before they can be used, which further increases the occupied space.

[0065] Based on this, the embodiment of the present application proposes a variable frequency electric control system and electronic equipment, which overcomes the problems of high cost, high complexity and large space occupied by the variable frequency integrated machine products in the related technology. The variable frequency electric control system includes: a main power module, an auxiliary power module, a transistor drive module and a main control module; the main power module is electrically connected to the input source, the auxiliary power module, the transistor drive module and the motor; the auxiliary power module is electrically connected to the transistor drive module and the main control module, and the auxiliary power module is used to take power from the DC bus of the main power module and supply power to the transistor drive module and the main control module; the transistor drive module is electrically connected to the main control module, and the transistor drive module is used to drive the on and off of each transistor in the main power module under the control of the main control module. In the variable frequency electric control system provided by the present application, the circuit topology and structural layout of the main power module are simplified, which can significantly reduce the size of the whole machine, occupy less structural space, drive more simply, and greatly save costs; by designing the auxiliary power module to directly take power from the high-voltage DC bus of the main power module, and then supply power to the transistor drive module and the main control module, the power supply efficiency can be greatly improved, and the traditional transformer can be omitted, so as to achieve the purpose of saving space and reducing costs.

[0066] The variable frequency electric control system and electronic equipment provided in the embodiments of the present application are specifically described through the following embodiments, and the variable frequency electric control system is first described.

[0067] The present application embodiment provides a variable frequency electric control system, referring to Figure 1 , Figure 1 A schematic diagram of the structure of a variable frequency electric control system provided in one embodiment of the present application, the variable frequency electric control system comprises: a main power module 10, an auxiliary power module 20, a transistor drive module 30 and a main control module 40;

[0068] The main power module 10 is electrically connected to the input source, the auxiliary power module 20, the transistor driving module 30 and the motor;

[0069] The auxiliary power module 20 is electrically connected to the transistor driving module 30 and the main control module 40. The auxiliary power module 20 is used to draw power from the DC bus of the main power module 10 and supply power to the transistor driving module 30 and the main control module 40.

[0070] The transistor driving module 30 is electrically connected to the main control module 40 . The transistor driving module 30 is used to drive the on and off of each transistor in the main power module 10 under the control of the main control module 40 .

[0071] It should be noted that, in the present embodiment, the input source may be a high-voltage AC bus. Compared with a conventional frequency converter, the frequency conversion electric control system provided in the present embodiment does not need to use a high-voltage 3300V withstand voltage IGBT or an NPC three-level topology in the main power module 10, thereby reducing complexity and design costs. At the same time, the present embodiment uses an auxiliary power supply module 20 to directly draw power from the high-voltage AC bus, thereby providing working power for the transistor drive module 30 and the main control module 40, eliminating the need for a conventional transformer, thereby further reducing space occupancy and reducing costs.

[0072] Reference Figure 2 In some feasible embodiments, the main power module 10 includes: a three-phase uncontrolled rectifier circuit 101, a DC bus pre-charging circuit 102, a DC filter circuit 103 and a three-phase full-bridge inverter circuit 104;

[0073] The three-phase uncontrolled rectifier circuit 101 is electrically connected to an input source, a DC bus pre-charging circuit 102, a DC filter circuit 103 and a three-phase full-bridge inverter circuit 104;

[0074] The DC bus pre-charging circuit 102 is electrically connected to the auxiliary power module 20 and the DC filter circuit 103;

[0075] The DC filter circuit 103 is electrically connected to the three-phase full-bridge inverter circuit 104;

[0076] The three-phase full-bridge inverter circuit 104 is electrically connected to the transistor driving module 30 and the motor.

[0077] Reference Figure 3 In some feasible embodiments, the above-mentioned variable frequency electric control system further includes:

[0078] A voltage-balanced discharge circuit 105 , the voltage-balanced discharge circuit 105 is electrically connected to the three-phase uncontrolled rectifier circuit 101 , the DC filter circuit 103 and the three-phase full-bridge inverter circuit 104 ;

[0079] The current sensor 106 is disposed between the three-phase full-bridge inverter circuit 104 and the motor.

[0080] It should be noted that, in this embodiment, current sensors do not need to be set on all circuits between the three-phase full-bridge inverter circuit 104 and the motor. For example, when the three-phase full-bridge inverter circuit 104 is connected to two motors, current sensors can be set on three of the six connections.

[0081] Reference Figure 4 In some feasible embodiments, the three-phase uncontrolled rectifier circuit 101 includes: a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6;

[0082] The first diode D1 and the fourth diode D4 are connected in series to form a first diode half-bridge unit, and the midpoint of the bridge arm of the first diode half-bridge unit is electrically connected to the first phase R of the input source;

[0083] The second diode D2 and the fifth diode D5 are connected in series to form a second diode half-bridge unit, and the midpoint of the bridge arm of the second diode half-bridge unit is connected to the second phase S of the input source;

[0084] The third diode D3 and the sixth diode D6 are connected in series to form a third diode half-bridge unit, and the midpoint of the bridge arm of the third diode half-bridge unit is connected to the third phase T of the input source;

[0085] The first end of the first diode half-bridge unit, the first end of the second diode half-bridge unit and the first end of the third diode half-bridge unit are electrically connected to the first end of the DC bus pre-charging circuit 102;

[0086] The second end of the first diode half-bridge unit, the second end of the second diode half-bridge unit and the second end of the third diode half-bridge unit are electrically connected to the second end of the DC filter circuit 103 and the second end of the three-phase full-bridge inverter circuit 104 .

[0087] As an example, in this embodiment, diodes D1, D2, D3, D4, D5, and D6 together form a three-phase uncontrolled rectifier circuit 101, wherein every two diodes D1, D4, D2, D5, D3, and D6 form a diode half-bridge unit, the connection point of D1 and D4 is the midpoint of the bridge arm of the first diode half-bridge unit, the connection point of D2 and D5 is the midpoint of the bridge arm of the second diode half-bridge unit, and the connection point of D3 and D6 is the midpoint of the bridge arm of the third diode half-bridge unit. The reverse withstand voltage of each diode is 3600V, and the current flowing through the diode can be selected according to the effective value of the rated input current of the inverter.

[0088] Reference Figure 4 In some feasible embodiments, the DC bus pre-charging circuit 102 includes: a pre-charging resistor RP1, a first thyristor SCR1 and a second thyristor SCR2;

[0089] A first end of the pre-charge resistor RP1, an anode of the first thyristor SCR1 and an anode of the second thyristor SCR2 are electrically connected to a first end of the three-phase uncontrolled rectifier circuit 101;

[0090] The second end of the pre-charging resistor RP1, the cathode of the first thyristor SCR1 and the cathode of the second thyristor SCR2 are electrically connected to the first end of the DC filter circuit 103;

[0091] The gate of the first thyristor SCR1 and the gate of the second thyristor SCR2 are electrically connected to the auxiliary power module 20 .

[0092] As an example, in this embodiment, the pre-charge resistor RP1 can be a high-voltage, low-loss thick-film non-inductive resistor, which is safe and reliable. The number of thyristors can be selected according to the power level of the frequency converter. In this embodiment, two thyristors are connected in parallel with the pre-charge resistor RP1, or only one thyristor can be used in parallel with the pre-charge resistor RP1, or three thyristors can be used in parallel with the pre-charge resistor RP1.

[0093] Reference Figure 4 In some feasible embodiments, the DC filter circuit 103 includes: a DC reactor L1, a first capacitor C1 and a second capacitor C2;

[0094] A first end of the DC reactor L1 is electrically connected to a second end of the DC bus pre-charging circuit 102;

[0095] The second end of the DC reactor L1 and the first end of the first capacitor C1 are electrically connected to the first end of the three-phase full-bridge inverter circuit 104;

[0096] The second end of the first capacitor C1 and the first end of the second capacitor C2 are electrically connected to the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit 104;

[0097] The second end of the second capacitor C2 is electrically connected to the second ends of the three-phase uncontrolled rectifier circuit 101 and the three-phase full-bridge inverter circuit 104 .

[0098] As an example, in this embodiment, the standard DC reactor L1 effectively improves the power factor of the whole machine. The first capacitor C1 and the second capacitor C2 can use customized steel shell film capacitors. Compared with a single cylindrical capacitor in parallel, the structural strength is higher, the volume is smaller, and the spatial structure layout is more convenient.

[0099] Reference Figure 4 , in some feasible embodiments, the voltage-balanced discharge circuit 105 includes: a first resistor R1 and a second resistor R2;

[0100] A first end of the first resistor R1 is electrically connected to a second end of the DC reactor L1, a first end of the first capacitor C1, and a first end of the three-phase full-bridge inverter circuit 104;

[0101] The second end of the first resistor R1 and the first end of the second resistor R2 are electrically connected to the second end of the first capacitor C1, the first end of the second capacitor C2 and the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit 104;

[0102] A second end of the second resistor R2 is electrically connected to a second end of the three-phase uncontrolled rectifier circuit 101 , a second end of the DC filter circuit 103 , and a second end of the three-phase full-bridge inverter circuit 104 .

[0103] As an example, in this embodiment, the first resistor R1 and the second resistor R2 together form a voltage-equalizing discharge circuit 105 , and high-voltage-withstand, low-loss thick-film non-inductive resistors are also selected, which are safe and reliable.

[0104] Reference Figure 4 In some feasible embodiments, the motor includes a first motor MR1 and a second motor MR2; the three-phase full-bridge inverter circuit 104 includes: a first transistor S1, a second transistor S2, a third transistor S3, a fourth transistor S4, a fifth transistor S5, a sixth transistor S6, a seventh transistor S7, an eighth transistor S8, a ninth transistor S9, a tenth transistor S10, an eleventh transistor S11 and a twelfth transistor S12, and the controlled end of each transistor is electrically connected to the transistor driving module 30;

[0105] The first transistor S1 and the second transistor S2 are connected in series to form a first upper half bridge, the third transistor S3 and the fourth transistor S4 are connected in series to form a first lower half bridge, the fifth transistor S5 and the sixth transistor S6 are connected in series to form a second upper half bridge, the seventh transistor S7 and the eighth transistor S8 are connected in series to form a second lower half bridge, the ninth transistor S9 and the tenth transistor S10 are connected in series to form a third upper half bridge, and the eleventh transistor S11 and the twelfth transistor S12 are connected in series to form a third lower half bridge;

[0106] The first end of the first upper half bridge, the first end of the second upper half bridge and the first end of the third upper half bridge are electrically connected to the second end of the DC reactor L1 and the first end of the first capacitor C1, the second end of the first upper half bridge, the second end of the second upper half bridge, the second end of the third upper half bridge, the first end of the first lower half bridge, the first end of the second lower half bridge and the first end of the third lower half bridge together constitute the midpoint of the three-phase bridge arm, the midpoint of the three-phase bridge arm is electrically connected to the second end of the first capacitor C1 and the first end of the second capacitor C2, the second end of the first lower half bridge, the second end of the second lower half bridge and the second end of the third lower half bridge are electrically connected to the second end of the three-phase uncontrolled rectifier circuit 101 and the second end of the DC filter circuit 103;

[0107] The midpoint of the bridge arm of the first upper half bridge, the midpoint of the bridge arm of the second upper half bridge and the midpoint of the bridge arm of the third upper half bridge are respectively electrically connected to the three-phase input terminal of the first motor MR1, and the midpoint of the bridge arm of the first lower half bridge, the midpoint of the bridge arm of the second lower half bridge and the midpoint of the bridge arm of the third lower half bridge are respectively electrically connected to the three-phase input terminal of the second motor MR2.

[0108] As an example, in this embodiment, transistors S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, and S12 together form a three-phase full-bridge inverter circuit 104, and the above transistors can all be IGBTs, wherein S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, and S12 each two IGBTs form an IGBT half-bridge unit, and 6 Infineon 1700V voltage EconoDUAL package half-bridge units are selected, with an insulation withstand voltage of 3400VA. C, in line with the insulation requirements of 1140V three-phase AC power grid, among which S1, S2, S5, S6, S9, S10 are connected to the upper busbar customized steel shell film capacitor terminals P and O, S3, S4, S7, S8, S11, S12 are connected to the lower busbar customized steel shell film capacitor terminals O and N. The shortest layout route from the film capacitor to the IGBT module can achieve extremely small busbar stray inductance design even without using laminated busbars. The superior busbar design can effectively suppress the IGBT peak voltage without using an absorption circuit, making the system more stable.

[0109] It can be understood that the connection point of S2 and S3, the connection point of S6 and S7, and the connection point of S10 and S11 together constitute the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit 104. The three connection points, the connection point between the first resistor R1 and the second resistor R2, and the connection point between the first capacitor C1 and the second capacitor C2 are all connected to each other. The midpoint of the bridge arm of the first upper half bridge is the connection point of S1 and S2, the midpoint of the bridge arm of the first lower half bridge is the connection point of S3 and S4, the midpoint of the bridge arm of the second upper half bridge is the connection point of S5 and S6, the midpoint of the bridge arm of the second lower half bridge is the connection point of S7 and S8, the midpoint of the bridge arm of the third upper half bridge is the connection point of S9 and S10, and the midpoint of the bridge arm of the third lower half bridge is the connection point of S11 and S12.

[0110] Reference Figure 5 In some feasible embodiments, the auxiliary power supply module 20 includes: a single-channel output power supply circuit 201, a multi-channel output power supply circuit 202, a first buck circuit 203, a linear voltage regulator circuit 204, a second buck circuit 205 and a pulse signal forward switching power supply circuit 206;

[0111] The input end of the single-channel output power supply circuit 201 is electrically connected to the DC bus of the main power module 10. The single-channel output power supply circuit 201 is used to draw power from the DC bus of the main power module 10 to output a first DC voltage of 24V.

[0112] The input end of the multi-channel output power supply circuit 202 is electrically connected to the output end of the single-channel output power supply circuit 201, and the multi-channel output power supply circuit 202 is used to output a first DC voltage of 24V, a second DC voltage of 15V, and a third DC voltage of 8V;

[0113] The input end of the first step-down circuit 203 is electrically connected to the output end of the multi-output power supply circuit 202, and the first step-down circuit 203 is used to step down the third DC voltage to output a fourth DC voltage of 5V;

[0114] The input end of the linear voltage regulator circuit 204 is electrically connected to the output end of the first step-down circuit 203, and the output end of the linear voltage regulator circuit 204 is electrically connected to the main control module 40. The linear voltage regulator circuit 204 is used to convert the fourth DC voltage into a fifth DC voltage of 3.3V to supply power to the main control module 40;

[0115] The input end of the second step-down circuit 205 is electrically connected to the output end of the single-channel output power supply circuit 201, and the second step-down circuit 205 is used to step down the first DC voltage to output a sixth DC voltage of 10.6V;

[0116] The input end of the pulse signal forward switching power supply circuit 206 is electrically connected to the output end of the second step-down circuit 205, the output end of the pulse signal forward switching power supply circuit 206 is electrically connected to the DC bus pre-charging circuit 102 of the main power module 10, and the enable end of the pulse signal forward switching power supply circuit 206 is electrically connected to the main control module 40.

[0117] As an example, in this embodiment, the auxiliary power supply module 20 includes: a flyback switching power supply with an input of 1140V inverter DC bus PN and a single 24V output (i.e., a single output power supply circuit 201), which can meet the 24V, 5A rated output under 900V~2000VDC input, and directly draws power from the inverter DC bus, replacing the traditional transformer solution of 1140VAC to 220VAC, and then from 220VAC input, output 24VDC, which greatly saves space and reduces costs; a flyback switching power supply with a single 24V input and multiple outputs of +24V, ±15V, +8V (i.e., a multiple output power supply circuit 202), which is more universal, stable and reliable, and has multiple outputs, and provides power for the control circuit, logic chip, operational amplifier circuit and main control module 40; considering that the power consumption of +5V (MCU and optical fiber power supply) is relatively large, and the power supply accuracy is required The requirements are high, and a buck power supply with +8V input and single +5V output (i.e., the first step-down circuit 203) and a +5V to +3.3V linear voltage regulator circuit 204 are used to provide power for the main control module 40; a 24V to 10.6V buck power supply (i.e., the second step-down circuit 205) provides power for the two-way thyristor SCR drive transformer; a forward switching power supply circuit 206 with an input of +10.6VDC and an output of two-way pulse signals with a frequency of 20kV, an amplitude of 8V, and a duty cycle of 50% is used. The forward power supply operation enable signal is controlled by the main control module 40. When the pre-charging is completed and the main control module 40 detects that the bus voltages P and N of the main power module 10 are greater than the undervoltage point and are stable and unchanged, it will output an enable signal to control the forward switching power supply to start working, and output a fixed frequency and duty cycle DC pulse signal to turn on the above-mentioned first thyristor SCR1 and second thyristor SCR2.

[0118] Reference Figure 6 In some feasible embodiments, the transistor driving module 30 includes: a PWM interlocking amplifier circuit 301, a fault feedback circuit 302, a forward transformer 303, and an optocoupler driving unit PC;

[0119] The input end of the PWM interlock amplifier circuit 301 is electrically connected to the main control module 40, and the output end of the PWM interlock amplifier circuit 301 is electrically connected to the optical coupler drive unit PC through an optical fiber. The PWM interlock amplifier circuit 301 is used to send a PWM wave to the optical coupler drive unit PC;

[0120] The input end of the fault feedback circuit 302 is electrically connected to the optical coupler driving unit PC, and the output end of the fault feedback circuit 302 is electrically connected to the main control module 40. The fault feedback circuit 302 is used to detect abnormalities and short circuit faults of the driving power supply;

[0121] The input end of the forward transformer 303 is electrically connected to the auxiliary power module 20, and the output end of the forward transformer 303 is electrically connected to the optocoupler drive unit PC. The forward transformer 303 is used to supply power to the optocoupler drive unit PC.

[0122] The optocoupler driving unit PC is electrically connected to the transistor in the main power module 10 , and the optocoupler driving unit PC is used to drive the transistor according to the PWM wave.

[0123] As an example, in this embodiment, the transistor driving module 30 can be an IGBT driving module. When the main control module 40 outputs six PWM signals, a six-way PWM interlock amplifier circuit 301 is set to drive the optical fiber based on the PWM signal, and effectively prevent the upper and lower bridge arm IGBTs from being directly connected and causing a bus short circuit; a six-way fault feedback circuit 302 is set to detect the IGBT driving power supply and IGBT short circuit faults, and upload them to the main control module 40 through optical fiber feedback, so as to detect and protect the IGBT; a six-way forward isolation power supply circuit is set, including a six-way forward transformer 303 whose input is a high-voltage flyback power supply and outputs 24V, Figure 5 Only two transformers of phase U are shown in the figure. VCC1 and VEE1 are about 25V, which provide power for driving optocoupler chip PC1 to drive S1 IGBT. Similarly, VCC2, VEE2, VCC3, VEE3, VCC4, and VEE4 provide driving power for S2, S3, and S4 IGBT respectively. At the same time, the primary and secondary sides of the driving optocoupler chip PC1 share the same ground, and the primary side of the driving optocoupler chip PC3 shares the power reference ground, so that one optical fiber receives PWM_U+ and sends it to the driving optocoupler chips PC1 and PC3 at the same time to realize S1 and S The three IGBTs are turned on and off at the same time. Since the primary sides of the driving optocoupler chips PC1 and PC3 have a common reference ground, the fault feedback signals of PC1 and PC3 (i.e., the fault information of IGBTs S1 and S3) can be collected at the same time, and the output signal FB_U+ is sent to the main control module 40 through the optical fiber. The same applies to the V and W phases. Finally, six optical fiber transmission and six optical fiber receiving circuits plus twelve optical couplers drive 12 IGBTs, which saves half the number of optical fibers compared to the traditional electric control system, greatly simplifies the electric control system, reduces costs, and saves space.

[0124] As an example, see Figure 7 In this embodiment, the main control module 40 may include an efficient 32-bit CPU; an MCU power supply and reset circuit; buttons and displays are implemented through a high-speed SPI communication circuit; external 485 and CAN communication circuits can provide real-time feedback on the operation data of the frequency converter, realizing multi-drive transmission applications; a storage EEPROM circuit can still save the operation fault data of the frequency converter when it is offline; the IGBT drive module is as above Figure 6, the MCU outputs six PWM signals to control the on and off of 12 IGBTs, greatly simplifying the electronic control system; the analog input AI circuit includes the upper and lower bus voltage PO and ON detection of the frequency converter, motor phase current detection, IGBT module temperature detection, and external analog input detection such as motor vibration sensor and torque sensor; the digital input DI circuit includes motor start and stop, forward and reverse commands; the analog output AO circuit has two 0-10VDC voltage outputs and 0-20mA current outputs, which can provide real-time feedback on the operating frequency of the frequency converter; the digital output DO circuit includes two open collector outputs and two relay outputs.

[0125] This embodiment provides a variable frequency electric control system, which uses six half-bridge 1700V withstand voltage IGBT modules for the inverter part of the three-phase AC 1140V power grid system to provide two three-phase full-bridge outputs for the six-phase motor. Compared with the NPC three-level topology, three clamping diode modules are saved, the system topology is simpler, the structural layout is simplified, and the size of the whole machine is reduced. Compared with the solution of using 3300V withstand voltage modules in the general two-level three-phase full-bridge topology, the structural space occupies less, the drive is simpler, and the cost is greatly saved; by using customized steel shell film capacitors, the shortest layout route from the bus capacitor to the IGBT module is achieved, and even if the laminated busbar is not used, the extremely small busbar stray inductance design can be achieved. The superior busbar design can effectively suppress the IGBT peak voltage without using an absorption circuit, making the system more stable and lowering the cost; the auxiliary power module directly draws power from the high-voltage DC bus of the frequency converter, and meets the wide voltage input range of 900VDC to 2000VDC, and outputs 24V to provide power for the IGBT drive module and the main control module, eliminating the 1140V to 220V transformer, greatly improving the power efficiency, saving space and reducing costs; through six optical fiber transmission, six optical fiber receiving circuits plus twelve optical couplers to drive 12 IGBTs, half the number of optical fibers is saved compared to the traditional electric control system, greatly simplifying the electric control system, reducing costs and saving space.

[0126] In addition, an embodiment of the present application also provides an electronic device, which includes the variable frequency electric control system provided by the above embodiment.

[0127] As an example, the electronic device may be an all-in-one frequency converter product.

[0128] Since the electronic device proposed in this embodiment includes the variable frequency electric control system proposed in the above embodiments, it has the beneficial effects of the above embodiments. For details of the specific working process and principle of the variable frequency electric control system, please refer to the variable frequency electric control system provided in the above embodiments, which will not be described one by one here, and they are all within the protection scope of this embodiment.

[0129] It should be noted that the technical solutions of the various embodiments of the present application can be combined with each other, but it must be based on the fact that they can be implemented by technical personnel in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0130] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0131] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the meaning of "and / or" appearing in the full text is to include three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B.

[0132] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0133] It should also be understood that the references to "one embodiment" or "some embodiments" described in the specification of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0134] The above are only optional embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A variable frequency electric control system, characterized in that: The variable frequency electric control system comprises: a main power module, an auxiliary power module, a transistor drive module and a main control module; The main power module is electrically connected to an input source, the auxiliary power module, the transistor drive module and the motor; The auxiliary power supply module is electrically connected to the transistor driving module and the main control module, and the auxiliary power supply module is used to draw power from the DC bus of the main power module and supply power to the transistor driving module and the main control module; The transistor driving module is electrically connected to the main control module, and is used to drive the on and off of each transistor in the main power module under the control of the main control module.

2. The variable frequency electric control system according to claim 1, characterized in that: The main power module includes: a three-phase uncontrolled rectifier circuit, a DC bus pre-charging circuit, a DC filter circuit and a three-phase full-bridge inverter circuit; The three-phase uncontrolled rectifier circuit is electrically connected to the input source, the DC bus pre-charging circuit, the DC filter circuit and the three-phase full-bridge inverter circuit; The DC bus pre-charging circuit is electrically connected to the auxiliary power supply module and the DC filter circuit; The DC filter circuit is electrically connected to the three-phase full-bridge inverter circuit; The three-phase full-bridge inverter circuit is electrically connected to the transistor drive module and the motor.

3. The variable frequency electric control system according to claim 2, characterized in that: The three-phase uncontrolled rectifier circuit comprises: a first diode, a second diode, a third diode, a fourth diode, a fifth diode and a sixth diode; The first diode and the fourth diode are connected in series to form a first diode half-bridge unit, and a midpoint of a bridge arm of the first diode half-bridge unit is electrically connected to a first phase of the input source; The second diode and the fifth diode are connected in series to form a second diode half-bridge unit, and the midpoint of the bridge arm of the second diode half-bridge unit is connected to the second phase of the input source; The third diode and the sixth diode are connected in series to form a third diode half-bridge unit, and the midpoint of the bridge arm of the third diode half-bridge unit is connected to the third phase of the input source; The first end of the first diode half-bridge unit, the first end of the second diode half-bridge unit and the first end of the third diode half-bridge unit are electrically connected to the first end of the DC bus pre-charging circuit; The second end of the first diode half-bridge unit, the second end of the second diode half-bridge unit and the second end of the third diode half-bridge unit are electrically connected to the second end of the DC filter circuit and the second end of the three-phase full-bridge inverter circuit.

4. The variable frequency electric control system according to claim 2, characterized in that: The DC bus pre-charging circuit comprises: a pre-charging resistor, a first thyristor and a second thyristor; The first end of the pre-charging resistor, the anode of the first thyristor and the anode of the second thyristor are electrically connected to the first end of the three-phase uncontrolled rectifier circuit; The second end of the pre-charging resistor, the cathode of the first thyristor and the cathode of the second thyristor are electrically connected to the first end of the DC filter circuit; The gate of the first thyristor and the gate of the second thyristor are electrically connected to the auxiliary power supply module.

5. The variable frequency electric control system according to claim 2, characterized in that: The DC filter circuit comprises: a DC reactor, a first capacitor and a second capacitor; The first end of the DC reactor is electrically connected to the second end of the DC bus pre-charging circuit; The second end of the DC reactor and the first end of the first capacitor are electrically connected to the first end of the three-phase full-bridge inverter circuit; The second end of the first capacitor and the first end of the second capacitor are electrically connected to the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit; The second end of the second capacitor is electrically connected to the second end of the three-phase uncontrolled rectifier circuit and the second end of the three-phase full-bridge inverter circuit.

6. The variable frequency electric control system according to claim 5, characterized in that: The variable frequency electric control system further includes: a voltage-sharing discharge circuit, the voltage-sharing discharge circuit being electrically connected to the three-phase uncontrolled rectifier circuit, the DC filter circuit and the three-phase full-bridge inverter circuit; The voltage-balanced discharge circuit comprises: a first resistor and a second resistor; The first end of the first resistor is electrically connected to the second end of the DC reactor, the first end of the first capacitor and the first end of the three-phase full-bridge inverter circuit; The second end of the first resistor and the first end of the second resistor are electrically connected to the second end of the first capacitor, the first end of the second capacitor and the midpoint of the three-phase bridge arm of the three-phase full-bridge inverter circuit; The second end of the second resistor is electrically connected to the second end of the three-phase uncontrolled rectifier circuit, the second end of the DC filter circuit and the second end of the three-phase full-bridge inverter circuit.

7. The variable frequency electric control system according to claim 5 or 6, characterized in that: The motor includes a first motor and a second motor; the three-phase full-bridge inverter circuit includes: a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor, a ninth transistor, a tenth transistor, an eleventh transistor and a twelfth transistor, and the controlled end of each of the transistors is electrically connected to the transistor driving module; The first transistor and the second transistor are connected in series to form a first upper half-bridge, the third transistor and the fourth transistor are connected in series to form a first lower half-bridge, the fifth transistor and the sixth transistor are connected in series to form a second upper half-bridge, the seventh transistor and the eighth transistor are connected in series to form a second lower half-bridge, the ninth transistor and the tenth transistor are connected in series to form a third upper half-bridge, and the eleventh transistor and the twelfth transistor are connected in series to form a third lower half-bridge; The first end of the first upper half bridge, the first end of the second upper half bridge and the first end of the third upper half bridge are electrically connected to the second end of the DC reactor and the first end of the first capacitor; the second end of the first upper half bridge, the second end of the second upper half bridge, the second end of the third upper half bridge, the first end of the first lower half bridge, the first end of the second lower half bridge and the first end of the third lower half bridge together constitute the midpoint of the three-phase bridge arm; the midpoint of the three-phase bridge arm is electrically connected to the second end of the first capacitor and the first end of the second capacitor; the second end of the first lower half bridge, the second end of the second lower half bridge and the second end of the third lower half bridge are electrically connected to the second end of the three-phase uncontrolled rectifier circuit and the second end of the DC filter circuit; The midpoint of the bridge arm of the first upper half bridge, the midpoint of the bridge arm of the second upper half bridge and the midpoint of the bridge arm of the third upper half bridge are respectively electrically connected to the three-phase input end of the first motor, and the midpoint of the bridge arm of the first lower half bridge, the midpoint of the bridge arm of the second lower half bridge and the midpoint of the bridge arm of the third lower half bridge are respectively electrically connected to the three-phase input end of the second motor.

8. The variable frequency electric control system according to claim 1, characterized in that: The auxiliary power supply module includes: a single-channel output power supply circuit, a multi-channel output power supply circuit, a first step-down circuit, a linear voltage stabilization circuit, a second step-down circuit and a pulse signal forward switching power supply circuit; The input end of the single-channel output power supply circuit is electrically connected to the DC bus of the main power module, and the single-channel output power supply circuit is used to draw power from the DC bus of the main power module; The input end of the multi-channel output power supply circuit is electrically connected to the output end of the single-channel output power supply circuit; The input end of the first step-down circuit is electrically connected to the output end of the multi-output power supply circuit; The input end of the linear voltage stabilizing circuit is electrically connected to the output end of the first step-down circuit, and the output end of the linear voltage stabilizing circuit is electrically connected to the main control module; The input end of the second step-down circuit is electrically connected to the output end of the single-channel output power supply circuit; The input end of the pulse signal forward switching power supply circuit is electrically connected to the output end of the second step-down circuit, the output end of the pulse signal forward switching power supply circuit is electrically connected to the DC bus pre-charging circuit of the main power module, and the enable end of the pulse signal forward switching power supply circuit is electrically connected to the main control module.

9. The variable frequency electric control system according to claim 1, characterized in that: The transistor driving module includes: a PWM interlocking amplifier circuit, a fault feedback circuit, a forward transformer, and an optocoupler driving unit; The input end of the PWM interlock amplifier circuit is electrically connected to the main control module, and the output end of the PWM interlock amplifier circuit is electrically connected to the optical coupler drive unit through an optical fiber, and the PWM interlock amplifier circuit is used to send a PWM wave to the optical coupler drive unit; The input end of the fault feedback circuit is electrically connected to the optical coupler drive unit, the output end of the fault feedback circuit is electrically connected to the main control module, and the fault feedback circuit is used to detect abnormalities and short circuit faults of the driving power supply; The input end of the forward transformer is electrically connected to the auxiliary power supply module, the output end of the forward transformer is electrically connected to the optocoupler drive unit, and the forward transformer is used to supply power to the optocoupler drive unit; The optocoupler driving unit is electrically connected to the transistor in the main power module, and the optocoupler driving unit is used to drive the transistor according to the PWM wave.

10. An electronic device, characterized in that: The electronic device comprises the variable frequency electric control system according to any one of claims 1 to 9.

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