A frequency converter control signal conversion module and a frequency converter control system

Abstract

The application provides a frequency converter control signal conversion module and a frequency converter control system. The control signal conversion module is connected with the frequency converter and the control system respectively. The control signal conversion module comprises a frequency converter connecting end and a control system connecting end. The control signal conversion module provided by the application only needs a single signal mode of the corresponding control system interface, can adapt to various control signal requirements of the frequency converter, greatly reduces the design difficulty, maintenance cost and manufacturing cost of the control system, reduces the possibility of wiring errors in construction, improves the reliability of long-term use of the control system, and greatly improves the universality of the control system and the control program.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of frequency converter control system, and particularly relates to a frequency converter control signal conversion module and a frequency converter control system. BACKGROUND

[0002] In a frequency converter closed-loop control system, the control system controls the frequency converter by sending start-stop signals, frequency signals and the like, and the frequency converter feeds back normal / abnormal signals, actual running frequency signals and the like to the control system. However, different types of frequency converters have different control modes, such as three-wire start, two-wire start, positive voltage start, negative voltage start, current signal frequency modulation, voltage signal frequency modulation, current signal frequency feedback, voltage signal frequency feedback and the like. If the control system itself is compatible with all the above modes, the control system will be extremely complex, difficult to design and maintain, prone to wiring errors during construction, inevitably have a large number of invalid lines, increase the cost, seriously reduce the system reliability, and greatly reduce the universality of the control system and the control program.

[0003] In order to make the control system compatible with different control mode frequency converters without increasing the complexity of the control system, a more reasonable way is to make the control system adopt a fixed set of input and output signals, and set a universal signal conversion module between the frequency converter and the control system, which converts the signals emitted by the two into the mode required by the other, thereby greatly reducing the complexity of the control system, reducing the design difficulty and manufacturing cost, and improving the long-term reliability of the system. SUMMARY

[0004] Therefore, the application aims to overcome the above problems in the prior art, and provides a frequency converter control signal conversion module and a frequency converter control system.

[0005] To achieve the above object, the technical scheme of the application is as follows:

[0006] A frequency converter control signal conversion module, which is connected with a frequency converter and a control system respectively.

[0007] The control signal conversion module comprises a frequency converter connection end and a control system connection end, the frequency converter connection end comprises interfaces C B1 , C B2 , C B3 , C B4 , C B5 , C B6 , C B7 , C B8 , C B9 , C B10 , CB11 C B12 The control system connection terminal includes interface C. K1 C K2 C K3 C K4 C K5 C K6 C K7 C K8 C K9 C K10 C K11 C K12 C K13 C K14 C K15、 C K16、 C K17 ;

[0008] The interface C B1 One end is connected to the negative terminal of the inverter's control frequency input, and the other end is connected through node C. Z7 Connect the secondary signal negative terminal of the first signal transmitter and interface C respectively. K1 Through interface C K1 Connect the control system to the manual control mode frequency output negative terminal;

[0009] The interface C B2 One end is connected to the positive input of the frequency converter, and the other end is connected through node C. Z6 Connect relay J respectively ZD Normally open contact J ZD-2 and interface C K2 Node C Z6 Through relay J ZD Normally open contact J ZD-2 Connect the positive terminal of the secondary signal of the first signal transmitter through interface C. K2 Connect the control system to the manual control mode frequency output positive terminal;

[0010] The interface C B3 One end connects to the inverter's built-in DC 10V+, and the other end connects to switch K. 2-1 The normally closed contact, and through switch K 2-1 Common terminal connection interface C K3 Through interface C K3 Connect the manual frequency control signal source to the control system;

[0011] The interface C B4 One end connects to the inverter's built-in DC 24V+, and the other end connects to node C. Z7 Connect potentiometer RP1 and interface C respectively. K4 Potentiometer RP1 is connected to resistor R3, and resistor R3 passes through node C.Z8 Connect switch K 2-1 Normally open contact, node C Z7 Through interface C K4 The inverter connected to the control system has its own DC 24V+.

[0012] The interface C B5 One end connects to the inverter's built-in DC 24V, and the other end connects to node C. Z1 Connect switches K respectively 2-2 The normally open contacts and control system of the frequency converter have a built-in DC 24V terminal, switch K 2-2 The public end is through node C Z7 Connected to the negative terminal of the secondary signal of the first signal transmitter;

[0013] Relay J ZD One end connects to interface C K6 Through interface C K6 The automatic control mode start signal is connected to the control system, and the other end is connected to node C. Z1 Through node C Z1 Connect to the inverter's built-in DC 24V;

[0014] The interface C K7 One end connects to the automatic mode inverter start signal of the control system, and the other end passes through relay J. ZD Normally open point J ZD-1 Then, through node C Z2 Connection interface C K8 Interface C K8 Connect the manual start signal to the frequency converter of the control system. Z2 The other side splits into two paths, one of which passes through relay J. BC After the coil, connect node C. Z1 The other path first passes through relay J. BC Normally open point J BC-2 Then at node C Z3 The circuit is divided into three paths: the first path connects to switch K. 1-1 K 1-2 On the positive pressure mode side, the second connection relay J YC On one side of the coil, the third connection resistor R 12 One side; relay J YC On the other side, the anode A of the unidirectional silicon controlled rectifier (SCR1) is connected, and the cathode K of the SCR1 is connected through node C. Z4 Connect one side of the parallel capacitor C2 and resistor R2, and connect the other side of capacitor C2 and resistor R2 to node C. Z1 resistance R 12 The other side passes through node C Z5It is divided into three paths: the first path is connected to the control electrode G of SCR1, and the second and third paths are connected in parallel with capacitor C1 and resistor R. 11 On one side, capacitor C1 and resistor R 11 Connect node C on the other side Z1 ;

[0015] The interface C B6 One end is connected to the holding terminal of the frequency converter, and the other end is connected to relay J. BC Normally open point J BC-1 Connect switch K 1-1 The common terminal; switch K 1-1 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end;

[0016] The interface C B7 One end is connected to the inverter's start terminal, and the other end is connected to relay J. YC Normally open point J YC-1 Connect switch K 1-2 The common terminal; switch K 1-2 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end.

[0017] The interface C B8 One end connects to the COM port of the frequency converter, and the other end connects to interface C. K9 Through interface C K9 Connect to the COM port of the control system;

[0018] The interface C B9 One end connects to the normal signal indicator terminal of the frequency converter, and the other end connects to interface C. K10 Through interface C K10 Connect the normal signal indicator terminal of the frequency converter in the control system;

[0019] The interface C B10 One end connects to the inverter's fault signal indicator, and the other end connects to interface C. K11 Through interface C K11 Connect the abnormal signal indicator terminal of the frequency converter in the control system;

[0020] The interface C B11 One end is connected to the positive terminal of the frequency feedback of the frequency converter, and the other end is connected to the positive terminal of the primary signal of the second signal transmitter.

[0021] The interface C B12 One end is connected to the negative terminal of the frequency feedback of the frequency converter, and the other end is connected to the negative terminal of the primary signal of the second signal transmitter.

[0022] The interface C K12 One end is connected to the positive terminal of the first frequency feedback of the control system, and the other end is connected to the positive terminals of the first and second secondary signals of the second signal transmitter. Interface C K13 One end is connected to the negative terminal of the first frequency feedback of the control system, and the other end is connected to the negative terminals of the first and second signals of the second signal transmitter. Interface C K14 One end is connected to the positive terminal of the second frequency feedback of the control system, and the other end is connected to the positive terminal of the second secondary signal of the second signal transmitter. Interface C K15 One end is connected to the negative terminal of the second frequency feedback of the control system, and the other end is connected to the negative terminal of the second secondary signal of the second signal transmitter.

[0023] The interface C K16 One end is connected to the positive terminal of the frequency output in the automatic control mode of the control system, and the other end is connected to the positive terminal of the primary signal of the first signal transmitter. Interface C K17 One end is connected to the negative terminal of the frequency output of the automatic control mode of the control system, and the other end is connected to the negative terminal of the primary signal of the first signal transmitter.

[0024] The present invention also provides a frequency converter control signal conversion system, including the above-mentioned control signal conversion module, as well as a frequency converter and a control system connected to the control signal conversion module.

[0025] Compared with existing technologies, the inverter control signal conversion module of this invention has the following advantages:

[0026] 1. The inverter control signal conversion module provided by this invention can be adapted to inverters with various control modes. Its starting method can be three-wire starting or two-wire starting, the starting and holding signals can be positive voltage or negative voltage, the frequency modulation signal can be analog current signal or analog voltage signal, and the frequency feedback signal can also be analog current signal or analog voltage signal. It covers all common control methods of inverters and has extremely high versatility.

[0027] 2. The inverter control signal conversion module provided by this invention requires only one set of signal modes for its corresponding control system interface, which can adapt to the various control signal requirements of the inverter. This greatly reduces the design difficulty, maintenance cost, and manufacturing cost of the control system, reduces the possibility of wiring errors during construction, improves the long-term reliability of the control system, and significantly enhances the versatility of the control system and control program.

[0028] 3. The inverter control signal conversion module provided by this invention only requires adjusting the position of the switch contacts within the module when switching control signal modes, without changing the wiring method of the control system and inverter. It is convenient to use, less prone to errors, and easy to construct.

[0029] 4. The inverter control signal conversion module provided by this invention supports both automatic and manual control modes at the control system end. However, the inverter control end interface is shared in both modes, so there is no need for the inverter to set up separate interfaces for automatic and manual control. It can be compatible with more types of inverters.

[0030] 5. The inverter control signal conversion module provided by this invention only requires the common standard DC 24V voltage for its internal control circuit, and is compatible with almost all common inverters and low-voltage control systems.

[0031] 6. The inverter control signal conversion module provided by this invention can simulate the control mode of a three-wire start inverter, which first connects and holds and then starts through a pulse signal, when the control system only outputs one inverter start command. This reduces the requirements on the control system and improves the adaptability of the control system. Attached Figure Description

[0032] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the inverter control signal conversion module created by the present invention. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] This invention provides a frequency converter control signal conversion module, which is connected to both the frequency converter and the control system. It should be noted that the frequency converter and control system used in this invention are existing products, and the requirements for the frequency converter and control system are all existing technologies, basically covering all frequency converters and control systems.

[0039] This invention creates a control system corresponding to the control signal conversion module, which has the functions of manually and automatically controlling the start and stop of the frequency converter, as well as manually and automatically controlling the frequency converter frequency. The control system divides the start and stop control of the frequency converter into three states: automatic, stop, and start. The state of the frequency converter is determined by control devices such as a three-position rotary switch. When the switch is in "automatic," the system enters automatic control mode, and the start / stop and frequency of the frequency converter are determined by the control system program. When the switch is in "stop," the frequency converter stops running; when the switch is in "start," the frequency converter runs, i.e., manually started, and the frequency is manually controlled by a potentiometer. There is an interlock between the three states of the frequency converter, meaning the system can only enter one of the three states at a time. Correspondingly, the automatic frequency control signal and the manual frequency control signal are also interlocked, and the control system can only send one frequency control signal at a time. In practical applications, the control system can be based on a common DDC controller, configured with corresponding control circuits, and common electronic components such as rotary switches, potentiometers, and frequency meters to achieve the above functions.

[0040] The control system should include at least the following interfaces:

[0041] (1) Automatic control mode start signal interface: digital output. When the control mode of the control system is switched to automatic mode, this interface outputs DC 24V+ voltage; otherwise, no signal is output.

[0042] (2) Automatic mode inverter start signal interface: digital output. When the control system has entered automatic mode and the control system requires the inverter to start, this interface outputs DC 24V+ voltage; otherwise, no signal is output.

[0043] (3) Inverter manual start signal interface: digital output. When the system enters manual start mode, this interface outputs DC 24V+ voltage; otherwise, no signal is output.

[0044] (4) Automatic control mode frequency output interface: Analog output. The output signal can be either DC 0-10V+ voltage or 0 / 4-20mA current, or other signal modes. The automatic mode frequency output signal is sent to the frequency input signal transmitter of the frequency converter (i.e., the first signal transmitter), converted into the signal mode required by the frequency converter, and then connected to the frequency converter.

[0045] (5) Manual frequency control signal source and frequency output interface: The signal source can be connected to the inverter's built-in DC 10V+ or built-in DC 24V+, depending on the frequency control signal mode required by the inverter. The positive terminal of the frequency output is the analog output, connected to the positive terminal of the inverter's control frequency input; the negative terminal is connected to the negative terminal of the inverter's control frequency input. The positive and negative terminals of the signal source and frequency output are simultaneously connected to a potentiometer in the control system. The output frequency control signal is adjusted by adjusting the potentiometer's resistance.

[0046] (6) The inverter has a built-in DC 24V interface: it has two positive and two negative terminals, which are connected to the two DC 24V terminals of the inverter respectively, and are used to power some functions of the system.

[0047] (7) Inverter Positive / Abnormal Signal Interface: This includes three interfaces: Inverter Normal, Inverter Abnormal, and Common (COM) terminal, which connect to the inverter's normal, abnormal, and common (COM) terminals, respectively. The control system's COM terminal inputs a current or voltage signal to the inverter's COM terminal. The inverter, based on its operating status, internally switches its COM terminal to either normal or abnormal mode, thus returning the COM terminal signal to the control system from the corresponding interface. Within the control system, a start signal can only be sent to the inverter when a signal is received at the inverter's normal interface.

[0048] (8) Inverter frequency feedback interface: There are 4 interfaces in total, divided into 2 groups. Each group has one interface for positive and one for negative terminals, which can simultaneously receive 2 sets of inverter frequency feedback signals. The 2 sets of frequency signals can be used for system frequency meters, system closed-loop control, etc. The frequency feedback signal can be either DC 0-10V+ voltage or 0 / 4-20mA current, or other signal modes.

[0049] The frequency converter has the following interfaces for receiving control signals and sending feedback signals:

[0050] (1) Control frequency input interface: This is required. It includes two interfaces, positive and negative, and accepts analog signal input. The signal can be DC 0-10V voltage or 0 / 4-20mA current signal.

[0051] (2) Holding Interface: This is required. It receives digital signal input, which can be positive voltage (DC 24V+) or negative voltage (DC 24V- provided by the inverter). In inverters with three-wire start mode, this point is used for the inverter holding signal input; in inverters with two-wire start mode, this point corresponds to the inverter start signal input.

[0052] (3) Start-up interface: This interface is required when the frequency converter uses three-wire start-up. It is used to receive the start-up signal and pulse input. The signal can be positive voltage (DC 24V+) or negative voltage (DC 24V- provided by the frequency converter). This interface is not required when the frequency converter uses two-wire start-up.

[0053] (4) DC 10V power supply interface built into the frequency converter: This interface is required when the frequency converter control frequency input signal is a DC 0-10V analog voltage signal. When the control frequency input signal is an analog current signal, a DC 10V interface is not required.

[0054] (5) The inverter has a built-in DC 24V power supply interface: it must have one positive and one negative interface.

[0055] (6) Inverter positive / abnormal feedback interface: Must be present, including one interface each for normal, abnormal and common (COM) terminals. The COM terminal is used to receive current or voltage signals from the control system. The inverter connects the COM terminal to either normal or abnormal according to its own operating status, thereby outputting the COM terminal signal.

[0056] (7) Frequency feedback of inverter: It is required, with one positive and one negative interface, and outputs analog signals, which can be DC 0-10V voltage, 0 / 4-20mA current, etc.

[0057] like Figure 1 As shown, the control signal conversion module includes an inverter connection terminal and a control system connection terminal mounted on a circuit board. The inverter connection terminal includes an interface C. B1 C B2 C B3 C B4 C B5 C B6 C B7 C B8 C B9 C B10 C B11 C B12 The control system connection terminal includes interface C. K1 C K2 C K3 C K4 C K5 C K6C K7 C K8 C K9 C K10 C K11 C K12 C K13 C K14 C K15、 C K16 C K17 ;

[0058] In one embodiment, interface C B4 One side connects to the inverter's built-in DC 24V+, and the other side connects to interface C. K4 Interface C B5 Connect one side to the inverter's built-in DC 24V, and the other side to interface C. K5 This interface is used to supply power to some functions of the control system.

[0059] In one embodiment, relay J ZD One end connects to interface C K6 Through interface C K6 The automatic control mode start signal is connected to the control system, and the other end is connected to node C. Z1 Through node C Z1 Connect to the inverter's built-in DC 24V;

[0060] The interface C K7 One end connects to the automatic mode inverter start signal of the control system, and the other end passes through relay J. ZD Normally open point J ZD-1 Then, through node C Z2 Connection interface C K8 Interface C K8 Connect the manual start signal of the frequency converter in the control system; C Z2 The other side splits into two paths, one of which passes through relay J. BC After the coil, connect node C. Z1 The other path first passes through relay J. BC Normally open point J BC-2 Then at node C Z3 The circuit is divided into three paths: the first path connects to switch K. 1-2 K 1-2 On the positive pressure mode side, the second connection relay J YC On one side of the coil, the third connection resistor R 12 One side; relay J YC On the other side, the anode A of the unidirectional silicon controlled rectifier (SCR1) is connected, and the cathode K of the SCR1 is connected through node C. Z4 Connect one side of the parallel capacitor C2 and resistor R2, and connect the other side of capacitor C2 and resistor R2 to node C. Z1 resistance R12 The other side passes through node C Z5 It is divided into three paths: the first path is connected to the control electrode G of SCR1, and the second and third paths are connected in parallel with capacitor C1 and resistor R. 11 On one side, capacitor C1 and resistor R 11 Connect node C on the other side Z1 ;

[0061] The interface C B6 One end is connected to the holding terminal of the frequency converter, and the other end is connected to relay J. BC Normally open point J BC-1 Connect switch K 1-1 The common terminal; switch K 1-1 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end;

[0062] The interface C B7 One end is connected to the inverter's start terminal, and the other end is connected to relay J. YC Normally open point J YC-1 Connect switch K 1-2 The common terminal; switch K 1-2 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end.

[0063] When using it, switch K should be set according to the inverter's hold and start signal mode requirements. 1-1 K 1-2 Move the switch to the corresponding position. In positive pressure control mode, connect the corresponding switch to node C. Z3 In negative pressure control mode, the corresponding switch will be turned on at node C. Z1 .

[0064] When the control system switches to automatic control mode, it sends a request to interface C. K6 Provides DC 24V+ voltage, relay J ZD When the coil is energized, normally open contact J ZD-1 Close. When the control system sends an inverter start signal, it sends a signal to interface C. K7 Provides a voltage of DC 24V+, then through J ZD-1 Transfer DC 24V+ voltage to node C Z2 .

[0065] When the control system switches to manual start mode, it sends a signal to interface C. K8 Provides DC 24V+ voltage, also at node C. Z2Provides DC 24V+ voltage. That is, regardless of whether the inverter is started in automatic or manual mode, the start signal DC 24V+ must pass through node C. Z2 Transmission. Due to the interlock between the automatic and manual start states of the frequency converter in the control system, interface C... K7 C K8 The two will not send start signals at the same time, so as not to cause system control chaos.

[0066] Node C Z2 The DC 24V+ signal from the inverter, used for manual or automatic start-up, drives relay J. BC Normally open point J BC-1 J BC-2 Closed. Among them, the interface CB6 connected to the inverter's holding end is via J... BC-1 K 1-1 Connect the corresponding control signal, J BC-2 Then the control voltage DC 24V+ will be applied from node C. Z2 Passed to node C Z3 When the inverter holding terminal is in positive voltage mode, K 1-1 Connect node C Z3 Transmit the DC 24V+ signal to interface C B6 When using negative pressure mode, K 1-1 Connect node C Z1 Connect the inverter's built-in DC24V input interface C B6 That is, when the control system sends a start signal, the inverter holds the interface C connected to the start / stop signal. B6 Control signals were received immediately.

[0067] When the control system sends an automatic or manual start signal for the frequency converter, node C Z3 The start signal DC 24V+ is applied. This voltage first charges capacitor C1, and finally, the voltage at node C... Z5 This generates a voltage divider, the specific value of which is determined by the resistor R. 11 R 12 The proportion is determined by node C. Z5 Voltage division, that is, when the voltage at the gate (G) of the unidirectional thyristor SCR1 reaches the voltage required for SCR1 to conduct, the positive terminal (A) and negative terminal (K) of SCR1 conduct, and node C... Z3 The DC 24V+ at the point charges capacitor C2, and relay J... YC The coil is connected, and the normally open contact J... YC-1 Engagement. The inverter's start-up terminal is connected via J. YC-1 and switch K 1-2 Connect the corresponding control signal; the signal source is the same as the inverter's holding terminal, so it will not be described again. As capacitor C2 charges, node C... Z4When the voltage increases, the forward conduction current of SCR1 is less than its operating holding current, so SCR1 stops conducting, and relay J... YC Power off, normally open contact J YC-1 Disconnecting the circuit allows the inverter's start signal to become a pulse signal. Furthermore, since capacitor C1 requires a certain amount of time to charge, relay J... YC Normally open point J YC-1 It must be later than relay J BC Normally open point J BC-1 Engagement means that the inverter's holding terminal receives the control signal first, followed by the starting terminal. Since the starting signal is a pulse signal, the above circuit structure can completely simulate the control signal of a three-wire starting inverter.

[0068] It should be noted that the above usage is based on a three-wire start inverter, but this control signal conversion module is also applicable to inverters using two-wire start. Specifically, the inverter holding interface of this signal conversion module is connected to the start interface of the two-wire start inverter, while the inverter start interface of this signal conversion module is not connected to the inverter. In this way, control of the two-wire start inverter can be achieved.

[0069] In one embodiment, interface C K1 One side connects to the control system's manual control mode frequency output negative terminal, and the other side connects via interface C. B1 Connect the inverter to the negative terminal of the control frequency input. Interface C K2 One side connects to the control system's manual control mode frequency output positive terminal, and the other side connects to C... B2 Connect the inverter to the positive terminal of the control frequency input.

[0070] Interface C K3 One side connects to the manual frequency control signal source of the control system, and the other side connects to switch K. 2-1 Public terminal. K 2-1 There are two contacts, one side is connected to interface C. B3 Connect the inverter's built-in DC 10V+, one side via node C. Z8 Connect resistor R3 and potentiometer RP1 in series, and then through node C. Z7 Connect to the inverter which has its own DC 24V+.

[0071] The control system's automatic control mode frequency output positive terminal is connected to interface C. K16 The negative terminal is connected to interface C. K17 The primary frequency control signal is input to the first signal transmitter T1, and then converted into the control signal required by the frequency converter by the first signal transmitter T1. This invention creates a secondary signal that serves as the frequency converter control signal in automatic mode. The positive terminal of the secondary signal is connected to relay J. ZD Normally open contact J ZD-2 On one side, JZD-2 The other side passes through node C Z6 With interface C B2 Connection. The negative terminal of the secondary signal is connected through node C. Z7 With interface C B1 On the one hand, it connects through node C. Z7 Furthermore, with switch K 2-2 One side connection, K 2-2 The other side and C Z1 Connection. When K 2-2 When closed, interface C can be made B1 and node C Z1 Connecting means that the negative terminal of the inverter's control frequency input is connected to the inverter's built-in DC 24V terminal.

[0072] It should be noted that only when switch K 2-1 Connect to interface C B3 When on one side, the inverter must have its own DC 10V to connect to the control system as a signal source for manual frequency control. When switch K... 2-1 Connect node C Z8 When on one side, the DC 10V is not connected to the control system. In this invention, the inverter's built-in DC 10V is only used for manual frequency adjustment in voltage control mode. Therefore, when the inverter uses analog current signals to control the frequency, the DC 10V+ does not need to be connected to the control system. Furthermore, when the inverter uses analog current signals to control the frequency, the inverter's terminal interface C... B3 No wiring is required for the frequency converter, but the control system interface C... K3 The terminals still need to be wired normally according to the original rules, because when manually controlling the frequency, regardless of whether the frequency converter uses current mode or voltage mode, interface C must be used. K3 .

[0073] When using the inverter, adjust the manual frequency control connection method according to the inverter's control frequency input signal requirements. Specifically, when the inverter's control frequency input signal uses a 0-10V analog voltage signal, switch K... 2-1 Connection interface C B3 And switch K 2-2 Disconnect; when the inverter control frequency input signal uses an analog current signal, switch K... 2-1 Connect node C Z8 This is then achieved through resistor R3, potentiometer RP1, and node C. Z7 Connect the inverter to its built-in DC 24V+, and switch K 2-2 closure.

[0074] When the control system enters automatic control mode, relay J... ZD Power on, normally open contact J ZD-2When the signal is engaged, the positive terminal of the secondary signal emitted by the first signal transmitter T1 passes through node C. Z6 Access Interface C B2 This connects to the positive terminal of the inverter's control frequency input. The negative terminal of the secondary signal emitted by the first signal transmitter T1, according to the inverter's frequency control signal requirements, only passes through node C when using 0-10V analog voltage control. Z7 Connection interface C B1 When using analog current control, it is done through node C. Z7 and switch K 2-2 Simultaneously connect node C Z1 and Interface C B1 This forms a complete control signal loop. Due to internal interlocking within the control system, the interface C at the frequency output terminal of the manual control mode... K1 C K2 In automatic control mode, there is no signal output, and there will be no control signal confusion.

[0075] When the control system enters manual control mode, J ZD Power outage, J ZD-2 When disconnected, the inverter control frequency only comes from interface C. K1 C K2 As mentioned earlier, interface C K1 C K2 C K3 The same frequency modulation potentiometer RP2 is connected inside the control system, and the positive terminal of RP2 is connected to the manual frequency control signal source interface C. K3 The negative terminal is connected to the negative interface C of the frequency output terminal in manual control mode. K1 The output terminal is connected to the positive terminal of the frequency output terminal in manual control mode, C. K2 .

[0076] When the inverter control frequency input signal uses a DC 0~10V analog voltage signal, K 2-1 Connecting interface C B3 That is, connect the inverter's built-in DC 10V+; and interface C K1 Connecting interface C B1 This means connecting the inverter's built-in DC 10V- (the DC 10V- is on the same line as the negative terminal of the inverter's frequency input; this can be achieved through the inverter's own structure or by using a jumper wire). When the inverter's control frequency input signal uses an analog current signal, switch K... 2-1 Connect node C Z8 Potentiometer RP1 and resistor R3 pass through switch K 2-1 and Interface C K3 It then forms a series connection with RP2, through node C. Z7 The frequency converter provided here has a built-in DC 24V+ voltage to generate control current, and the current is transmitted through interface C.K2 Passing Interface C B2 Through interface C B2 Connect to the positive terminal of the inverter's control frequency input. Interface C K1 Then through node C Z7 and K 2-2 Connecting node C Z1 This means the frequency converter has its own DC 24V, thus forming a complete control loop. Potentiometer RP1 is used to calibrate the reference value of the total resistance of RP1, R3, and RP2. Its resistance is adjusted before the module is used for the first time and does not need to be adjusted during normal system operation.

[0077] In one embodiment, the interface C B8 One end connects to the COM port of the frequency converter, and the other end connects to interface C. K9 Through interface C K9 The interface C connects to the COM terminal of the control system. B9 One end connects to the normal signal indicator terminal of the frequency converter, and the other end connects to interface C. K10 Through interface C K10 Connect the normal signal indication terminal of the frequency converter in the control system; the interface C B10 One end connects to the inverter's fault signal indicator, and the other end connects to interface C. K11 Through interface C K11 Connect the abnormal signal indicator terminal of the frequency converter in the control system.

[0078] During use, the control system communicates via interface C. K9 To the inverter COM port C B8 The inverter sends a signal, and based on its own operating status, connects the COM terminal to its internal interface CB9 or CB. 10 This allows the signal to be connected to the normal or abnormal output terminal, and then the feedback signal is transmitted to the corresponding interface of the control system for use by the control system.

[0079] In one embodiment, the interface C B11 One end is connected to the positive terminal of the frequency feedback of the frequency converter, and the other end is connected to the positive terminal of the primary signal of the second signal transmitter; the interface C B12 One end is connected to the negative terminal of the frequency feedback of the frequency converter, and the other end is connected to the negative terminal of the primary signal of the second signal transmitter; the interface C K12 One end is connected to the positive terminal of the first frequency feedback of the control system, and the other end is connected to the positive terminals of the first and second secondary signals of the second signal transmitter. Interface C K13 One end is connected to the negative terminal of the first frequency feedback of the control system, and the other end is connected to the negative terminals of the first and second signals of the second signal transmitter. Interface C K14 One end is connected to the positive terminal of the second frequency feedback of the control system, and the other end is connected to the positive terminal of the second secondary signal of the second signal transmitter. Interface C K15One end is connected to the negative terminal of the second frequency feedback of the control system, and the other end is connected to the negative terminal of the second secondary signal of the second signal transmitter.

[0080] In use, the frequency output signal of the frequency converter is converted into the signal mode required by the frequency converter through the second signal transmitter T2, and extended into two signals to be connected to the control system for various purposes such as frequency meter and system closed-loop control.

[0081] This invention also provides a frequency converter control signal conversion system, including the aforementioned control signal conversion module, a frequency converter connected to the control signal conversion module, and a control system. The control signal conversion module is located between the frequency converter and the control system, acting as a bridge between them to transmit and convert control and feedback signals.

[0082] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A frequency converter control signal conversion module, characterized in that: The control signal conversion module is connected to the frequency converter and the control system respectively; The control signal conversion module includes a frequency converter connection terminal and a control system connection terminal. The frequency converter connection terminal includes an interface C. B1 C B2 C B3 C B4 C B5 C B6 C B7 C B8 C B9 C B10 C B11 C B12 The control system connection terminal includes interface C. K1 C K2 C K3 C K4 C K5 C K6 C K7 C K8 C K9 C K10 C K11 C K12 C K13 C K14 C K15 C K16 C K17 ; The interface C B1 One end is connected to the negative terminal of the inverter's control frequency input, and the other end is connected through node C. Z7 Connect the secondary signal negative terminal of the first signal transmitter and interface C respectively. K1 Through interface C K1 Connect the control system to the manual control mode frequency output negative terminal; The interface C B2 One end is connected to the positive input of the frequency converter, and the other end is connected through node C. Z6 Connect relay J respectively ZD Normally open contact J ZD-2 and interface C K2 Node C Z6 Through relay J ZD Normally open contact J ZD-2 Connect the positive terminal of the secondary signal of the first signal transmitter, interface C K2 Connect the control system to the manual control mode frequency output positive terminal; The interface C B3 One end connects to the inverter's built-in DC 10V+, and the other end connects to switch K. 2-1 The normally closed contact, and through switch K 2-1 Common terminal connection interface C K3 Through interface C K3 Connect the manual frequency control signal source to the control system; The interface C B4 One end connects to the inverter's built-in DC 24V+, and the other end connects to node C. Z7 Connect potentiometer RP1 and interface C respectively. K4 Potentiometer RP1 is connected to resistor R3, and resistor R3 passes through node C. Z8 Connect switch K 2-1 Normally open contact, node C Z7 Through interface C K4 The inverter connected to the control system has its own DC 24V+. The interface C B5 One end connects to the inverter's built-in DC 24V, and the other end connects to node C. Z1 Connect switches K respectively 2-2 Normally open contacts and via interface C K5 The inverter connected to the control system has its own DC 24V supply; switch K 2-2 The public end is through node C Z7 Connected to the negative terminal of the secondary signal of the first signal transmitter; Relay J ZD One end connects to interface C K6 Through interface C K6 The automatic control mode start signal is connected to the control system, and the other end is connected to node C. Z1 Through node C Z1 Connect to the inverter's built-in DC 24V; Interface C K7 One end connects to the automatic mode inverter start signal of the control system, and the other end passes through relay J. ZD Normally open point J ZD-1 Then, through node C Z2 Connection interface C K8 Interface C K8 Connect the control system inverter manual start signal, C Z2 The other side splits into two paths, one of which passes through relay J. BC After the coil, connect node C. Z1 The other path first passes through relay J. BC Normally open point J BC-2 Then at node C Z3 The circuit is divided into three paths: the first path connects to switch K. 1-1 K 1-2 On the positive pressure mode side, the second connection relay J YC On one side of the coil, the third connection resistor R 12 One side; relay J YC The other side of the coil is connected to the anode A of the unidirectional thyristor SCR1, and the cathode K of SCR1 is connected through node C. Z4 Connect one side of the parallel capacitor C2 and resistor R2, and connect the other side of capacitor C2 and resistor R2 to node C. Z1 Resistance R 12 The other side passes through node C Z5 It is divided into three paths: the first path is connected to the control electrode G of SCR1, and the second and third paths are connected in parallel with capacitor C1 and resistor R. 11 On one side, capacitor C1 and resistor R 11 Connect node C on the other side Z1 ; The interface C B6 One end is connected to the holding terminal of the frequency converter, and the other end is connected to relay J. BC Normally open point J BC-1 Connect switch K 1-1 The common terminal; switch K 1-1 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end; The interface C B7 One end is connected to the inverter's start terminal, and the other end is connected to relay J. YC Normally open point J YC-1 Connect switch K 1-2 The common terminal; switch K 1-2 There are two contacts, one side of which is connected to node C. Z3 One side is the positive pressure mode end; the other side is connected to node C. Z1 This is the negative pressure mode end; The interface C B8 One end connects to the COM port of the frequency converter, and the other end connects to interface C. K9 Through interface C K9 Connect to the COM port of the control system; The interface C B9 One end connects to the normal signal indicator terminal of the frequency converter, and the other end connects to interface C. K10 Through interface C K10 Connect the normal signal indicator terminal of the frequency converter in the control system; The interface C B10 One end connects to the inverter's fault signal indicator, and the other end connects to interface C. K11 Through interface C K11 Connect the abnormal signal indicator terminal of the frequency converter in the control system; The interface C B11 One end is connected to the positive terminal of the frequency feedback of the frequency converter, and the other end is connected to the positive terminal of the primary signal of the second signal transmitter. The interface C B12 One end is connected to the negative terminal of the frequency feedback of the frequency converter, and the other end is connected to the negative terminal of the primary signal of the second signal transmitter. The interface C K12 One end is connected to the positive terminal of the first frequency feedback of the control system, and the other end is connected to the positive terminals of the first and second secondary signals of the second signal transmitter. Interface C K13 One end is connected to the negative terminal of the first frequency feedback of the control system, and the other end is connected to the negative terminals of the first and second signals of the second signal transmitter. Interface C K14 One end is connected to the positive terminal of the second frequency feedback of the control system, and the other end is connected to the positive terminal of the second secondary signal of the second signal transmitter. Interface C K15 One end is connected to the negative terminal of the second frequency feedback of the control system, and the other end is connected to the negative terminal of the second secondary signal of the second signal transmitter. The interface C K16 One end is connected to the positive terminal of the frequency output in the automatic control mode of the control system, and the other end is connected to the positive terminal of the primary signal of the first signal transmitter. Interface C K17 One end is connected to the negative terminal of the frequency output of the automatic control mode of the control system, and the other end is connected to the negative terminal of the primary signal of the first signal transmitter.

2. A frequency converter control system, characterized in that: It includes the inverter control signal conversion module as described in claim 1, as well as the inverter and control system connected to the inverter control signal conversion module.

Images