A pre-thrown capacitor compensation device

Abstract

The present invention belongs to the technical field of power capacitors, and provides a pre-investment capacitor compensation device, including a cabinet body, on which are provided: a controller for detecting the power factor of the power system in real time and generating preset instructions; a compensation unit, in which a compensation capacitor is provided, for putting the compensation capacitor into the power system when the power factor detected by the controller is lower than a preset value; a switching unit for putting the compensation capacitor into the power system for operation according to the preset instructions; and a pre-investment unit for performing a pre-investment switching action before the compensation capacitor is put into the power system. The advantage of the present invention is that the pre-investment unit can automatically switch to the corresponding module position as needed, and the adjustable resistor and diode in the pre-investment unit are used to reduce the inrush current during the capacitor investment process. In addition, the pre-investment unit can be shared by each module, and exits the circuit during normal operation, which can increase the working life of the pre-investment unit, while simplifying the wiring of the device and reducing product costs.

Description

Technical Field

[0001] The present invention relates to the technical field of power capacitors, and in particular to a pre-investment type capacitor compensation device. Background Art

[0002] Low-voltage reactive power compensation devices are used in power systems to improve the power factor of the power grid, reduce losses in power transformers and transmission lines, and improve power supply efficiency. Therefore, reactive power compensation plays a very important role in power systems. There are various low-voltage reactive power compensation devices available, among which the parallel capacitor compensation method is simple, flexible, and convenient, and is currently the predominant reactive power compensation method in the market. Capacitor compensation devices generate inrush current during the switching process of the capacitors, which is detrimental to the normal operation of the device. To limit current, a reactor is usually connected in series with the capacitor circuit. However, improper selection of reactor and capacitor parameters can cause harmonic amplification, leading to overcurrent and heating of the capacitors and reactors. Furthermore, during device maintenance, the reactive power compensation device must first be de-energized. If a component is damaged, replacing it requires disconnecting and wiring. Maintenance work requires long power outages and inconvenience. Summary of the Invention

[0003] The object of the present invention is to provide a pre-invested capacitor compensation device to solve the above-mentioned problem.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A pre-invested capacitor compensation device includes a cabinet body, on which are provided:

[0006] A controller for detecting the power factor of the power system in real time and generating preset instructions;

[0007] a compensation unit, in which a compensation capacitor is provided, for putting the compensation capacitor into the power system when the power factor detected by the controller is lower than a preset value;

[0008] The switching unit is used to put the compensation capacitor into the power system for operation according to preset instructions;

[0009] The pre-switching unit is used to perform pre-switching action before the compensation capacitor is put into the power system.

[0010] Furthermore, a drive motor is provided at the bottom of the cabinet, and the drive motor is electrically connected to the controller;

[0011] The driving motor is also fixedly connected to a lifting mechanism arranged in a vertical direction, and the lifting mechanism is connected to the pre-feeding unit, so that the pre-feeding unit can move up and down along the lifting mechanism.

[0012] Furthermore, the switching unit is provided with a contact CZ11 and a contact CZ21;

[0013] The contact CZ11 is electrically connected to a first static contact provided on the cabinet, and the contact CZ21 is electrically connected to a second static contact provided on the cabinet.

[0014] Furthermore, the compensation unit is provided with a contact CZ12 and a contact CZ32;

[0015] The contact CZ12 is electrically connected to a third static contact provided on the cabinet, the contact CZ32 is electrically connected to a fourth static contact provided on the cabinet, and a control switch K2 is electrically connected between the first static contact and the third static contact.

[0016] Furthermore, the pre-investment unit is provided with a contact CZ22 and a contact CZ31;

[0017] The pre-cutting unit slides along the propulsion mechanism groove provided on the switching unit, so that the contact CZ22 is electrically connected to the second static contact and the contact CZ31 is electrically connected to the fourth static contact.

[0018] Furthermore, the pre-investment unit is provided with an adjustable resistor, a diode and a resistor electric mechanism;

[0019] One end of the adjustable resistor is connected to the contact CZ22, the other end is connected to the anode of the diode, and the cathode of the diode is connected to the contact CZ31;

[0020] The resistor electric mechanism is connected to the controller and is used to adjust the resistance value of the adjustable resistor according to a signal from the controller.

[0021] Furthermore, one end of the compensation capacitor is grounded, and the other end is connected to the contact CZ12.

[0022] Furthermore, a switching switch K1 is provided in the switching unit. One end of the switching switch K1 is connected to the power bus, and the other end is connected to the contact CZ11 and the contact CZ12 respectively.

[0023] Furthermore, interlocking devices are provided in both the switching unit and the compensation unit. When the switching unit is put into operation in the power system, the interlocking rod in the interlocking device is connected to the interlocking hole provided on the cabinet, so that the switching unit and the compensation unit cannot move relative to the cabinet.

[0024] Compared with the prior art, the present invention has at least the following beneficial effects:

[0025] (1) The present invention provides a pre-investment type capacitor compensation device, in which the pre-investment unit can automatically switch to the corresponding module position as needed, and utilizes the adjustable resistor and diode in the pre-investment unit to reduce the inrush current during the capacitor investment process;

[0026] (2) Each unit in the device is connected to the external circuit through movable contacts. When replacing components, the entire unit can be removed, reducing maintenance time;

[0027] (3) The pre-investment unit of the present invention can be shared by all modules and can be withdrawn from the circuit during normal operation, thereby increasing the service life of the pre-investment unit and simplifying the wiring of the capacitor compensation device, thereby reducing product costs and improving product reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an overall schematic diagram of an embodiment of the present invention;

[0029] Figure 2 2 is a schematic structural diagram of a switching unit in an embodiment of the present invention;

[0030] Figure 3 is a schematic structural diagram of a compensation unit in an embodiment of the present invention;

[0031] Figure 4 2 is a schematic structural diagram of a pre-delivery unit in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of contact wiring in an embodiment of the present invention;

[0033] Figure 6 It is the overall circuit wiring diagram of the embodiment of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, in the present invention, descriptions such as "first," "second," and "one" are for descriptive purposes only and should not be understood to indicate or imply their relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0036] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the accompanying drawings, but the present invention is not limited to these embodiments.

[0039] like Figure 1 As shown, the present invention provides a pre-investment type capacitor compensation device, comprising a cabinet body, on which a controller, a compensation unit, a switching unit and a pre-investment unit are arranged;

[0040] The controller is used to detect the power factor of the power system in real time and generate preset instructions. The compensation unit is used to put the compensation capacitor into the power system when the power factor detected by the controller is lower than the preset value. The switching unit is used to put the compensation capacitor into the power system for operation according to the preset instructions. The pre-switching unit is used to perform a pre-switching action before the compensation capacitor is put into the power system.

[0041] The switching unit and compensation unit are designed to be multiple sets according to the actual project, while only one set of controller and pre-start unit is required.

[0042] like Figure 2-Figure 4 As shown, the switching unit includes a switching switch K1, a contact CZ11, a contact CZ21 and an interlocking device. One end of the switching switch K1 is connected to the power bus, and the other end is connected to the contact CZ11 and the contact CZ12 respectively.

[0043] The pre-investment unit includes an adjustable resistor R, a diode D, a contact CZ22, a contact CZ31, a lifting mechanism and a resistor electric mechanism. One end of the adjustable resistor R is connected to the contact CZ22, and the other end is connected to the positive electrode of the diode D. The negative electrode of the diode R is connected to the contact CZ31. The resistor electric mechanism is connected to the controller and is used to adjust the resistance value of the adjustable resistor R according to the signal of the controller.

[0044] The compensation unit includes a compensation capacitor, an interlocking device, a contact CZ12 and a contact CZ32. One end of the compensation capacitor is grounded, and the other end is connected to the contact CZ12.

[0045] In order to prevent the switching unit and the compensation unit from being operated incorrectly when powered on, an interlocking device is provided. When the switching unit is put into operation in the power system, the interlocking rod in the interlocking device is inserted into the interlocking hole (not shown in the figure) provided on the cabinet, so that the switching unit and the compensation unit cannot move relative to the cabinet.

[0046] The above three units are all equipped with unit entry and exit control buttons and manual entry and exit control mechanisms. The unit entry and exit control buttons are connected to the controller. The operator can use the buttons on each unit to realize electric operation to push the unit to the connection position; similarly, the button can be used to realize electric operation to withdraw the unit to the separation position. In addition, considering that electric operation is not possible under maintenance and emergency situations, the advancement and exit operations can be carried out through manual control.

[0047] like Figure 5 As shown, the wiring state is that each unit is in a separated state and all contacts are in an unconnected state.

[0048] When the switching unit is in the engaged position, contact CZ11 contacts the first static contact, and contact CZ21 contacts the second static contact. When the pre-steering unit slides along the propulsion mechanism slot, bringing it into the engaged position, contact CZ31 contacts the fourth static contact, and contact CZ22 contacts the second static contact. When the compensation unit is in the engaged position, contact CZ32 contacts the fourth static contact, and contact CZ12 contacts the third static contact. Furthermore, the first and second static contacts are electrically connected via control switch K2.

[0049] The working principle of the present invention is: the operator can install the switching unit and the compensation unit in the corresponding module according to the engineering configuration requirements, such as Figure 1 As shown, there are 6 modules in total. Each unit is initially in a separated position and is pushed to a connected position by pressing a button on the panel.

[0050] When the device is working, the switching unit and compensation are in the connection position, and the pre-switching unit is in the connection position of the first layer by default, such as Figure 5 As shown, at this time, the connection relationship of the circuit in the device is that contact CZ21 is connected to contact CZ22, and contact CZ31 is connected to contact CZ32. Because the control switch K2 is not actuated, contact CZ11 and contact CZ12 are in a disconnected state.

[0051] The controller detects the power factor of the power system in real time. When it detects that the power factor of the power system does not meet the set requirements, it sends a control signal, which activates the switching switch K1. The switching switch K1 includes two contacts. When the contacts of the switching switch K1 are closed, the coil LS in the interlocking device will be energized, and the interlocking rod will be inserted into the interlocking hole provided on the cabinet, so that the switching unit and the compensation unit cannot move relative to the cabinet. The compensation capacitor is connected to the busbar through the adjustable resistor R and the diode D. The adjustable resistor is at the maximum resistance position at the beginning. Together with the diode D, it can reduce the starting current of the compensation capacitor and suppress the influence of harmonic current. After receiving the switching signal, the resistor electric mechanism is activated, causing the resistance of the adjustable resistor R to gradually decrease until it reaches zero. After reaching zero, the pre-transfer unit sends a signal to close the contact LW, energize the coil of the control switch K2, close the normally open contact of the control switch K2, connect the contact CZ11 and the contact CZ12, and put the compensation capacitor into the circuit. The pre-transfer unit completes the pre-transfer task and exits to the separation position. At the same time, the adjustable resistor returns to the starting position, that is, the position of the maximum resistance value, waiting for the signal from the controller.

[0052] During operation, if the controller needs to exit the operation of the compensation capacitor, the controller sends a signal to control the switching switch K1 to disconnect. At this time, the contact of K1 in the circuit of the control switch K2 is disconnected, and the control switch K2 is also disconnected, and the compensation capacitor will exit operation.

[0053] In addition, if the controller needs to put another group into operation after the first group of capacitors has been put into operation, the controller sends a signal to control the drive motor of the lifting mechanism, adjusting the pre-operation unit to descend to the second group module position. Once in position, the propulsion mechanism pushes the pre-operation unit to the connection position, and the controller sends a second group of switching action signals. The working process is the same as the first group. The pre-operation unit completes the switching task. After the second group of capacitors is put into operation, the pre-operation unit withdraws to the separation position and waits for the controller's signal. If a third group of capacitors needs to be put into operation, the pre-operation unit reaches the third group position according to the controller's signal to complete the pre-operation task.

[0054] If the switching unit and compensation unit need maintenance or replacement of components, the corresponding unit can be withdrawn for maintenance and repair. The switching units can backup each other, and the compensation units can gradually backup each other, which can reduce equipment maintenance and repair time.

[0055] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A pre-invested capacitor compensation device, characterized in that: The utility model comprises a cabinet body, on which are arranged: A controller for detecting the power factor of the power system in real time and generating preset instructions; a compensation unit, in which a compensation capacitor is provided, for putting the compensation capacitor into the power system when the power factor detected by the controller is lower than a preset value; The switching unit is used to put the compensation capacitor into the power system for operation according to preset instructions; Pre-switching unit, used to perform pre-switching action before the compensation capacitor is put into the power system; A drive motor is provided at the bottom of the cabinet, and the drive motor is electrically connected to the controller; The driving motor is also fixedly connected to a lifting mechanism arranged in a vertical direction, and the lifting mechanism is connected to the pre-feeding unit so that the pre-feeding unit can move up and down along the lifting mechanism; When the first set of compensation capacitors has been put into operation, when the controller determines that another set of compensation capacitors needs to be put into operation, the controller sends a signal to control the drive motor to adjust the pre-operation unit to descend to the position of the second set of compensation capacitors, and then the controller sends a second set of switching switch action signals to enable the pre-operation unit to complete the switching task; after the second set of compensation capacitors is put into operation, the pre-operation unit withdraws to the separation position and waits for the signal from the controller.

2. A pre-invested capacitor compensation device according to claim 1, characterized in that: The switching unit is provided with a contact CZ11 and a contact CZ21; The contact CZ11 is electrically connected to a first static contact provided on the cabinet, and the contact CZ21 is electrically connected to a second static contact provided on the cabinet.

3. The pre-investment capacitor compensation device according to claim 2, characterized in that: The compensation unit is provided with a contact CZ12 and a contact CZ32; The contact CZ12 is electrically connected to a third static contact provided on the cabinet, the contact CZ32 is electrically connected to a fourth static contact provided on the cabinet, and a control switch K2 is electrically connected between the first static contact and the third static contact.

4. The pre-investment capacitor compensation device according to claim 3, characterized in that: The pre-throw unit is provided with contact CZ22 and contact CZ31; The pre-cutting unit slides along the propulsion mechanism groove provided on the switching unit, so that the contact CZ22 is electrically connected to the second static contact and the contact CZ31 is electrically connected to the fourth static contact.

5. The pre-investment capacitor compensation device according to claim 4, characterized in that: The pre-investment unit is provided with an adjustable resistor, a diode and a resistor electric mechanism; One end of the adjustable resistor is connected to the contact CZ22, the other end is connected to the anode of the diode, and the cathode of the diode is connected to the contact CZ31; The resistor electric mechanism is connected to a controller and is used to adjust the resistance value of the adjustable resistor according to a signal from the controller.

6. The pre-investment capacitor compensation device according to claim 3, characterized in that: One end of the compensation capacitor is grounded, and the other end is connected to the contact CZ12.

7. The pre-investment capacitor compensation device according to claim 2, characterized in that: The switching unit is further provided with a switching switch K1 , one end of the switching switch K1 is connected to the power bus, and the other end is connected to the contact CZ11 and the contact CZ12 respectively.

8. The pre-investment capacitor compensation device according to claim 1, characterized in that: The switching unit and the compensation unit are both provided with an interlocking device. When the switching unit is put into operation in the power system, the interlocking rod in the interlocking device is connected to the interlocking hole provided on the cabinet, so that the switching unit and the compensation unit cannot move relative to the cabinet.

Images