Multi-load frequency converter

Abstract

The utility model discloses a multi-load frequency converter, which comprises a transformer set, an input end of the transformer set is connected with an external power supply, the transformer set is used for converting the external power supply into a power supply of a specified voltage grade and inputting the power supply to a rectification switch cabinet, and the specified voltage grade is a voltage grade required by the rectification switch cabinet; the output end of the transformer set is connected with the input end of the rectification switch cabinet, and the rectification switch cabinet is used for rectifying accessed alternating current into direct current; the output end of the rectification switch cabinet is connected with the input end of the frequency conversion cabinet, the frequency conversion cabinet comprises a plurality of inversion units, and each inversion unit inverts accessed direct current into alternating current; the output end of the frequency conversion cabinet is connected with the motors, each inversion unit is connected with the corresponding motor, and all the motors are connected with equipment to be used.

Description

Technical Field

[0001] The utility model belongs to the technical field of frequency converters, and in particular relates to a multi-load frequency converter. Background Art

[0002] Currently, the inverters on the market are usually single-drive, dual-drive and triple-drive, and can carry one to three loads. If more loads are required, multiple inverters need to be configured for coordinated use. In many scenarios, the inverter output voltage is not high enough, such as less than 1140V. However, when a larger output power is required, the output current will be very large. When the voltage is not high enough and the output current is large, the performance of a single inverter is not easy to meet, and multiple inverters need to occupy more space, and the cost also increases accordingly.

[0003] Therefore, providing a frequency converter to meet the requirement of high output power when the frequency converter output voltage is not high is a technical problem to be solved by those skilled in the art. Utility Model Content

[0004] The purpose of the utility model is to solve the technical problem in the prior art that a single inverter cannot output a large power when the voltage is not high enough. To this end, the utility model provides a multi-load inverter, which includes:

[0005] The input end of the transformer set is connected to the external power supply, and is used to convert the external power supply into a power supply of a specified voltage level and input it into the rectifier switch cabinet, wherein the specified voltage level is the voltage level required by the rectifier switch cabinet;

[0006] The output end of the transformer set is connected to the input end of the rectifier switch cabinet, and the rectifier switch cabinet is used to rectify the incoming alternating current into direct current;

[0007] The output end of the rectifier switch cabinet is connected to the input end of the frequency conversion cabinet, and the frequency conversion cabinet includes a plurality of inverter units, each of which inverts the input direct current into alternating current;

[0008] The output end of the frequency conversion cabinet is connected to the motor, wherein each inverter unit is connected to the corresponding motor, and all motors are connected to the equipment to be used.

[0009] Furthermore, the inverter unit specifically includes a circuit breaker and a power unit, the circuit breaker is connected to the DC power, the circuit breaker is also connected to the power unit, the power unit is used to invert the DC power into AC power, and the power unit is also connected to the motor.

[0010] Furthermore, the power unit also includes a resolver communication interface, an optical fiber communication interface and a main control 485 communication interface.

[0011] Furthermore, the power unit also includes a heat dissipation fan.

[0012] Furthermore, the power unit also includes a 24V power interface and a 220V power interface.

[0013] Furthermore, the input end of the frequency conversion cabinet is a DC molded case circuit breaker, and each inverter unit corresponds to two DC molded case circuit breakers, corresponding to two poles connected to the DC power.

[0014] Furthermore, the rectifier switch cabinet includes a plurality of rectifier units, and the rectifier units include:

[0015] The incoming line end, as an input end of the rectifier switch cabinet, includes three wiring terminals, which are respectively connected to one end of the corresponding contact switch in the contactor, and the other end of the contact switch is connected to the input end of the corresponding rectifier bridge group, the first output ends of the three rectifier bridge groups serve as the first output ends of the rectifier unit, and the second output ends of the three rectifier bridge groups serve as the second output ends of the rectifier unit;

[0016] Among them, the first output end of the rectifier unit is also connected to one end of the sub-capacitor group, the second output end of the rectifier unit is also connected to the other end of the sub-capacitor group, the capacitors in the sub-capacitor group are connected in series, and each capacitor in the sub-capacitor group is an absorption capacitor.

[0017] Furthermore, the first output ends of all the rectifier units serve together as the first output end of the rectifier switch cabinet, and the second output ends of all the rectifier units serve together as the second output end of the rectifier switch cabinet. The first output end of the rectifier switch cabinet is connected to one end of the capacitor module, and the second output end of the rectifier switch cabinet is connected to the other end of the capacitor module. The capacitor module includes multiple capacitor groups, and the capacitor groups are connected in parallel. The capacitor group includes multiple capacitors, and the capacitors in the capacitor group are connected in series.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] The utility model provides a multi-load frequency converter. Compared with the prior art, the frequency converter comprises a transformer set, an input end of which is connected to an external power supply for converting the external power supply into a power supply of a specified voltage level and inputting the power supply into a rectifier switch cabinet, wherein the specified voltage level is the voltage level required by the rectifier switch cabinet; the output end of the transformer set is connected to the input end of the rectifier switch cabinet, and the rectifier switch cabinet is used to rectify the connected alternating current into direct current; the output end of the rectifier switch cabinet is connected to the input end of a frequency converter cabinet, and the frequency converter cabinet comprises a plurality of inverter units, and each inverter unit inverts the connected direct current into alternating current; the output end of the frequency converter cabinet is connected to a motor, wherein each inverter unit is connected to a corresponding motor, and all motors are connected to equipment to be used. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of this specification, the drawings required for use in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 The figure is a schematic diagram of the structure of a multi-load frequency converter provided in an embodiment of this specification;

[0022] Figure 2 The figure shows a schematic diagram of the structure of the inverter unit provided in the embodiment of this specification;

[0023] Figure 3 The figure shows a schematic diagram of the structure of the rectifier unit provided in the embodiment of this specification. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0025] like Figure 1 The structure diagram of the multi-load inverter provided by the embodiment of this specification is shown. Although this specification provides the structure shown in the following embodiment or the accompanying drawings, the structure may include more or fewer structures after partial merging based on routine or without creative labor, and these structures are not limited to the structures shown in the embodiments or the accompanying drawings of this specification. When the structure is applied in an actual device or terminal product, it can be executed sequentially or in parallel according to the embodiment or module structure.

[0026] The multi-load inverter provided in the embodiments of this specification includes:

[0027] The input end of the transformer set is connected to the external power supply, and is used to convert the external power supply into a power supply of a specified voltage level and input it into the rectifier switch cabinet, wherein the specified voltage level is the voltage level required by the rectifier switch cabinet;

[0028] The output end of the transformer set is connected to the input end of the rectifier switch cabinet, and the rectifier switch cabinet is used to rectify the incoming alternating current into direct current;

[0029] The output end of the rectifier switch cabinet is connected to the input end of the frequency conversion cabinet, and the frequency conversion cabinet includes a plurality of inverter units, each of which inverts the input direct current into alternating current;

[0030] The output end of the frequency conversion cabinet is connected to the motor, wherein each inverter unit is connected to the corresponding motor, and all motors are connected to the equipment to be used.

[0031] Specifically, the transformer set includes four groups of outputs, and the transformer set is also a set of phase-shifting transformers. Each of the four groups of outputs is rectified by the rectifier switch cabinet with 6 pulses, so for the entire frequency converter cabinet, it is 24 pulses. This method has a lower ripple voltage, very small harmonics, more stable DC bus voltage, and easier heat dissipation for the rectifier part, which is more economical in terms of cost. When the output voltage of the inverter is low (1140V) (relative to the output voltage of higher-level inverters, such as 3.3kV, 6kV, 10kV, etc.), with a load with a rated power of 6750kW, the output current will be very large, which is difficult to meet at this voltage level. Through a multi-transmission multi-load inverter, one inverter can be used as a load with 10 motors at the same time. The 10 motors are transmitted through a gearbox to achieve a high-power load together.

[0032] Among them, each inverter unit can be controlled individually and can be freely combined and used according to actual work needs. Under the condition that the voltage level remains unchanged, multiple smaller power motors can work together to drive a high-power load through mutual cooperation, which improves the reliability of the equipment and maximizes the guarantee that the construction process required on site is not affected. The specific number of inverter units can be flexibly adjusted according to the situation.

[0033] In an embodiment of the present application, the frequency converter cabinet includes a plurality of inverter units, and each inverter unit specifically includes a circuit breaker and a power unit. The input end of the frequency converter cabinet is a DC molded case circuit breaker, that is, a circuit breaker. Each inverter unit corresponds to two DC molded case circuit breakers, for example, corresponding to the two poles connected to the DC power. The circuit breaker is connected to the DC power, and the circuit breaker is also connected to the power unit. The power unit is used to invert the DC power into AC power, and the power unit is also connected to the motor. The power unit also includes a rotary transformer communication interface, an optical fiber communication interface, and a main control 485 communication interface. The power unit also includes a heat dissipation fan. The power unit also includes a 24V power supply interface and a 220V power supply interface.

[0034] like Figure 2The diagram shows the structure of the inverter unit. The input end of the circuit breaker QF19 is connected to the DC P+ busbar, the output end of the circuit breaker QF19 is connected to the P port of the power unit, the input end of the circuit breaker QF20 is connected to the DC N- busbar, and the output end of the circuit breaker QF20 is connected to the N port of the power unit. The four poles of the two circuit breakers are connected in series, which can better exert the arc extinguishing ability of the four poles. The power unit includes a resolver communication interface, a cooling fan, an optical fiber communication interface, an AC220V port, a 24V power port, an emergency stop signal port, and a main control 485 communication interface. The power unit outputs three-phase electricity of U, V and W.

[0035] In an embodiment of the present application, the rectifier switch cabinet includes multiple groups of rectifier units, and the rectifier units include:

[0036] The incoming line end, as an input end of the rectifier switch cabinet, includes three wiring terminals, which are respectively connected to one end of the corresponding contact switch in the contactor, and the other end of the contact switch is connected to the input end of the corresponding rectifier bridge group. The first output ends of the three rectifier bridge groups serve as the first output ends of the rectifier unit, and the second output ends of the three rectifier bridge groups serve as the second output ends of the rectifier unit. The rectifier bridge is two rectifier diodes connected in series in the same direction. Two rectifier bridges form a rectifier bridge group, and the input end of the rectifier bridge is the connection point of the two rectifier diodes;

[0037] Among them, the first output end of the rectifier unit is also connected to one end of the sub-capacitor group, the second output end of the rectifier unit is also connected to the other end of the sub-capacitor group, the capacitors in the sub-capacitor group are connected in series, and each capacitor in the sub-capacitor group is an absorption capacitor.

[0038] Among them, the first output ends of all the rectifier units serve together as the first output end of the rectifier switch cabinet, and the second output ends of all the rectifier units serve together as the second output end of the rectifier switch cabinet. The first output end of the rectifier switch cabinet is connected to one end of the capacitor module, and the second output end of the rectifier switch cabinet is connected to the other end of the capacitor module. The capacitor module includes multiple capacitor groups, and the capacitor groups are connected in parallel. The capacitor group includes multiple capacitors, and the capacitors in the capacitor group are connected in series.

[0039] like Figure 3The figure shows a schematic diagram of the structure of the rectifier unit. The inlet terminal XS11 of the rectifier unit includes three terminals R11, S11 and T11, which are respectively connected to one end of the corresponding contact switch in the contactor KM11. The contactor KM11 includes three contact switches R1, S1 and T1. The terminal R11 is connected to the port 1 of the contact switch R1, the terminal S11 is connected to the port 3 of the contact switch S1, the terminal T11 is connected to the port 5 of the contact switch T1, the port 2 of the contact switch R1 is connected to the first rectifier bridge group through the fuse FU1, the port 4 of the contact switch S1 is connected to the second rectifier bridge group, and the port 6 of the contact switch T1 is connected to the third rectifier bridge group through the fuse FU2. The rectifier bridge groups are connected, the first rectifier bridge group includes a rectifier bridge V11 and a rectifier bridge V11', the second rectifier bridge group includes a rectifier bridge V12 and a rectifier bridge V12', the third rectifier bridge group includes a rectifier bridge V13 and a rectifier bridge V13', the two rectifier bridges in each rectifier bridge group are connected in parallel, the first output ends of the three rectifier bridge groups serve as the first output ends of the rectifier unit, the second output ends of the three rectifier bridge groups serve as the second output ends of the rectifier unit, the first output end of the rectifier unit is also connected to one end of the sub-capacitor group, the second output end of the rectifier unit is also connected to the other end of the sub-capacitor group, and the capacitors in the sub-capacitor group, namely C17, C18 and C19, are connected in series.

[0040] It should be understood that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intervening element at the same time; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element at the same time. In addition, the "connection" used here may include wireless connection; the term "and / or" used includes any unit and all combinations of one or more associated listed items.

[0041] In addition, each functional unit in each embodiment of the present application may be integrated into one processing module, or each unit may exist physically separately, or two or more units may be integrated into one module.

[0042] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0043] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

[0044] The above contents are further detailed descriptions of the present invention in combination with specific preferred implementations, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A multi-load inverter, characterized in that The frequency converter comprises: The input end of the transformer set is connected to the external power supply, and is used to convert the external power supply into a power supply of a specified voltage level and input it into the rectifier switch cabinet, wherein the specified voltage level is the voltage level required by the rectifier switch cabinet; The output end of the transformer set is connected to the input end of the rectifier switch cabinet, and the rectifier switch cabinet is used to rectify the incoming alternating current into direct current; The output end of the rectifier switch cabinet is connected to the input end of the frequency conversion cabinet, and the frequency conversion cabinet includes a plurality of inverter units, each of which inverts the input direct current into alternating current; The output end of the frequency conversion cabinet is connected to the motor, wherein each inverter unit is connected to the corresponding motor, and all motors are connected to the equipment to be used.

2. The multi-load inverter according to claim 1, characterized in that: The inverter unit specifically includes a circuit breaker and a power unit. The circuit breaker is connected to the DC power. The circuit breaker is also connected to the power unit. The power unit is used to invert the DC power into AC power. The power unit is also connected to the motor.

3. The multi-load inverter according to claim 2, characterized in that: The power unit also includes a resolver communication interface, an optical fiber communication interface and a main control 485 communication interface.

4. The multi-load inverter according to claim 2, characterized in that: The power unit also includes a heat dissipation fan.

5. The multi-load inverter according to claim 2, characterized in that: The power unit also includes a 24V power supply interface and a 220V power supply interface.

6. The multi-load inverter according to claim 1, characterized in that: The input end of the frequency conversion cabinet is a DC molded case circuit breaker, and each inverter unit corresponds to two DC molded case circuit breakers, corresponding to the two poles connected to the DC power.

7. The multi-load inverter according to claim 1, characterized in that: The rectifier switch cabinet includes multiple groups of rectifier units, and the rectifier units include: The incoming line end, as an input end of the rectifier switch cabinet, includes three wiring terminals, which are respectively connected to one end of the corresponding contact switch in the contactor, and the other end of the contact switch is connected to the input end of the corresponding rectifier bridge group, the first output ends of the three rectifier bridge groups serve as the first output ends of the rectifier unit, and the second output ends of the three rectifier bridge groups serve as the second output ends of the rectifier unit; Among them, the first output end of the rectifier unit is also connected to one end of the sub-capacitor group, the second output end of the rectifier unit is also connected to the other end of the sub-capacitor group, the capacitors in the sub-capacitor group are connected in series, and each capacitor in the sub-capacitor group is an absorption capacitor.

8. The multi-load inverter according to claim 7, characterized in that: The first output ends of all rectifier units serve together as the first output end of the rectifier switch cabinet, and the second output ends of all rectifier units serve together as the second output end of the rectifier switch cabinet. The first output end of the rectifier switch cabinet is connected to one end of the capacitor module, and the second output end of the rectifier switch cabinet is connected to the other end of the capacitor module. The capacitor module includes multiple capacitor groups, and the capacitor groups are connected in parallel. The capacitor group includes multiple capacitors, and the capacitors in the capacitor group are connected in series.

Images