A general-purpose power saving device for electric machines

Abstract

The utility model discloses a motor general power saving equipment, including power saving drive circuit and with the control circuit intercommunication of power saving drive circuit: the one end of rectifier module in power saving drive circuit is connected with three -phase ac power supply, and the other end of rectifier module exports direct current through electromagnetic interference suppression module, and the output of electromagnetic interference suppression module is parallel with RC filter module, and the direct current after filtering is exported to the external load and provides drive power after inverting through several groups of inverter module, and the control circuit includes: the bypass control circuit and power saving control circuit loop of realizing circuit switching control through interlocking module, and the bypass control circuit includes: the line voltage of one route is drawn from two phase lines in three -phase ac power supply as line power supply, and the line power supply exports direct current through ac -dc conversion module. The utility model discloses a motor general power saving equipment has good equipment compatibility, and excellent outdoor work stability and stable electrical safety.

Description

Technical Field

[0001] This utility model relates to the field of energy-saving equipment technology, and in particular to a general-purpose energy-saving device for motors. Background Technology

[0002] The main circuit of existing industrial energy-saving cabinets basically consists of a mains power inlet switch, a three-phase rectifier bridge, a pre-charge power-on circuit, a DC bus capacitor and voltage equalization resistor, an inverter and drive control circuit, a current sampling sensor, output and bypass switches, and a human-machine interface. In energy-saving mode, the output voltage is adjusted by changing the output frequency according to load changes, thereby achieving energy saving. When a fault occurs in the energy-saving circuit, it switches to mains bypass mode.

[0003] However, existing energy-saving devices still have the following technical problems in actual use: 1. Rectified DC voltage contains significant EMC (electromagnetic harmonic) interference. While smoothing reactors or LCL filters are commonly used, their large size limits cabinet dimensions, often resulting in less desirable alternatives. Furthermore, the high-order harmonics they generate can interfere with other transmission and metering equipment.

[0004] 2. If the equipment switches to bypass mode due to a minor fault or interference, it cannot reliably switch from bypass to power-saving mode after the fault is restored, and the equipment needs to be shut down for conversion.

[0005] 3. Currently, the control power supply relies on AC mains power. When the mains power fluctuates, it can easily cause the contactor coil to trip or bounce due to undervoltage, affecting the reliable operation of the equipment.

[0006] 4. When operating in a humid environment, the inner wall of the cabinet is prone to dampness or condensation. Simply relying on a temperature and humidity controller to control the resistance heating can easily cause problems such as excessively high local temperatures. Utility Model Content

[0007] This invention overcomes the shortcomings of the prior art and provides a universal energy-saving device for motors, which has good equipment compatibility, excellent outdoor working stability, and stable electrical safety.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a general-purpose energy-saving device for motors, including an energy-saving drive circuit installed in an industrial energy-saving cabinet and a control circuit interconnected with the energy-saving drive circuit: the energy-saving drive circuit includes: a rectifier module, one end of which is connected to a three-phase AC power supply, and the other end of which outputs DC power through an electromagnetic interference suppression module. An RC filter module is connected in parallel to the output end of the electromagnetic interference suppression module for outputting filtered DC power. The filtered DC power is inverted by several sets of inverter modules and then output to an external load to provide drive power. The control circuit includes: a bypass control circuit and a power-saving control circuit loop that achieve circuit switching control through an interlock module; The bypass control circuit includes: drawing a line voltage from two phase lines of the three-phase AC power supply as the line power source; the line power source is converted to DC power through an AC-DC conversion module. The power-saving control circuit includes: an electromagnetic interference suppression module that outputs DC power, which is then converted to DC power by a DC-DC converter.

[0009] In a preferred embodiment of this utility model, the input terminal of the AC / DC conversion module is connected to the line power supply through switch BK1, and the output terminal of the AC / DC conversion module is output through diode VD1. The input terminal of the DC-DC converter module is connected to the output terminal of the electromagnetic interference suppression module through fuse FU, and the output terminal of the DC-DC converter module is output through diode VD2.

[0010] In a preferred embodiment of this utility model, the interlocking module includes: a relay KY, the mutual inductance coil of the relay KY is connected in parallel to the input terminal of the AC-DC conversion module; the normally open switch of the relay KY is connected in parallel across the two ends of the diode VD1; and the normally closed switch of the relay KY is connected in parallel across the two ends of the diode VD2.

[0011] In a preferred embodiment of this utility model, the rectifier module includes a three-phase bridge rectifier circuit. The three input terminals of the three-phase bridge rectifier circuit are connected to the three phase lines of the three-phase AC power supply through a circuit breaker QF. The two output terminals of the three-phase bridge rectifier circuit are output through an electromagnetic interference suppression module.

[0012] In a preferred embodiment of this utility model, the RC filter module includes a series-connected RC parallel circuit one and an RC parallel circuit two. The RC parallel circuit one includes a resistor R1, a capacitor C1, a resistor R2, and a capacitor C2 connected in parallel; the RC parallel circuit two includes a resistor R3, a capacitor C3, a resistor R4, and a capacitor C4 connected in parallel.

[0013] In a preferred embodiment of this invention, each inverter module includes two sets of IGBT switching units connected in series. Each set of IGBT switching units has a freewheeling diode connected in parallel across its two ends. The output of the series node of the two sets of IGBT switching units in each inverter module is used as a drive power supply and connected to an external load.

[0014] In a preferred embodiment of this utility model, a temperature sensor TA is installed on each of the three phase lines of the three-phase AC power supply, and the coil TA that is mutually inducted with the temperature sensor TA is connected in series with the ammeter PA.

[0015] In a preferred embodiment of this utility model, a current transformer is provided on the line leading out of the inverter module for monitoring the three-phase current; And / or, the positive output terminal of the electromagnetic interference suppression module is led out through switch K1 and connected to the RC filter module.

[0016] Compared with the prior art, the beneficial effects achieved by this utility model are as follows: The present invention discloses a universal energy-saving device for motors, which has good equipment compatibility, excellent outdoor working stability, and stable electrical safety.

[0017] 1. Reduces EMC interference signals and ensures circuit stability; enables seamless switching between power-saving mode and bypass mode.

[0018] 2. Dual power supply online redundancy is used to solve equipment failures caused by unstable power supply or power outage. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a schematic diagram of the control circuit in a universal energy-saving device for motors according to this utility model. Figure 1 ; Figure 2 This is a schematic diagram of the control circuit in a universal energy-saving device for motors according to this utility model. Figure 2 ; Figure 3 This is a front view structural diagram of an EMI differential mode inductor element in a general-purpose energy-saving device for motors according to this utility model; Figure 4 This is a side view of the EMI differential mode inductor element in a general-purpose energy-saving device for motors according to this utility model. Figure 5 This is an axial view structural schematic diagram of an EMI differential mode inductor element in a general-purpose energy-saving device for motors according to this utility model; Among them, 1 is the housing; 11 is the mounting cavity; 2 is the cover; 21 is the glue-filling hole; and 22 is the wire-passing hole. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features therein are detailed descriptions of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features therein can be combined with each other.

[0022] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] Example 1, as Figure 1 As shown, a general-purpose energy-saving device for motors includes an energy-saving drive circuit installed in an industrial energy-saving cabinet and a control circuit interconnected with the energy-saving drive circuit.

[0024] Specifically, the power-saving drive circuit includes a rectifier module, which comprises a three-phase bridge rectifier circuit. The three input terminals of the three-phase bridge rectifier circuit are connected to the three phase lines of the three-phase AC power supply via a circuit breaker QF. The two output terminals of the three-phase bridge rectifier circuit are output through an electromagnetic interference suppression module. In this embodiment, the electromagnetic interference suppression module uses an existing EMI differential-mode inductor. In the rectified DC voltage circuit, the positive and negative DC currents pass through the EMI differential-mode inductor wound with a high-permeability magnetic material, filtering out electromagnetic interference from the power grid and effectively suppressing differential-mode high-frequency interference in the rectifier circuit.

[0025] Specifically, an RC filter module is connected in parallel to the output of the electromagnetic interference suppression module. The RC filter module includes two parallel RC circuits: RC parallel circuit one and RC parallel circuit two. RC parallel circuit one includes resistors R1 and C1, resistors R2 and C2 connected in parallel; RC parallel circuit two includes resistors R3 and C3, resistors R4 and C4 connected in parallel. The RC filter module smooths the DC voltage, suppresses voltage fluctuations, provides a stable DC power supply for subsequent circuits, and outputs filtered DC power. The filtered DC power is then inverted by several inverter modules and output to provide drive power to the external load. Each inverter module includes two IGBT switching units connected in series. Each IGBT switching unit has a freewheeling diode connected in parallel across its terminals. The output of the series node of the two IGBT switching units in each inverter module serves as the drive power supply connected to the external load. Through the high-frequency switching action of the IGBT switching units, the DC power is inverted into AC power, which can be used to drive motors and achieve frequency conversion control.

[0026] Specifically, the control circuit includes: a bypass control circuit and a power-saving control circuit loop that achieve circuit switching control through an interlock module; the bypass control circuit includes: drawing a line voltage from two phase lines of the three-phase AC power supply as a line power source; the line power source outputs DC power through an AC / DC conversion module, the input terminal of the AC / DC conversion module is connected to the line power source through switch BK1, and the output terminal of the AC / DC conversion module is output through diode VD1. The power-saving control circuit includes: the DC power output from the electromagnetic interference suppression module is output through the DC conversion module. The input terminal of the DC conversion module is connected to the output terminal of the electromagnetic interference suppression module through fuse FU, and the output terminal of the DC conversion module is output through diode VD2. The interlock module includes: a relay KY, the mutual inductance coil of relay KY is connected in parallel at the input terminal of the AC / DC conversion module; the normally open switch of relay KY is connected in parallel across diode VD1; the normally closed switch of relay KY is connected in parallel across diode VD2.

[0027] Working principle: This utility model discloses a universal energy-saving device for motors, which features good equipment compatibility, excellent outdoor working stability, and stable electrical safety. While achieving traditional energy-saving applications, this utility model effectively suppresses the generation of its own harmonic content and improves the device's EMC anti-interference capability. It employs a dual-power online redundancy design, effectively reducing device malfunctions caused by poor control power supply at a relatively low cost.

[0028] In use, in the rectified DC voltage circuit, the positive and negative DC voltages pass through the EMI differential mode inductor wound with high magnetic permeability material, which effectively suppresses the differential mode high-frequency interference of the rectified circuit.

[0029] In the control circuit, one power supply path converts AC mains power into DC control voltage, while the other path converts DC control voltage via a DC-DC module from the DC bus. The positive terminals of the two control voltage outputs are connected in series with diodes VD1 and VD2 respectively, and then connected in parallel to provide the control power. Diode VD1 in the AC conversion power supply branch is connected in parallel to the normally open contact of the normally open switch of relay KY, while diode VD2 in the DC conversion power supply branch is connected in parallel to the normally closed contact of the normally closed switch of relay KY. The inductor coil of relay KY is powered by AC mains power. Under normal circumstances, when the input mains power is normal, the control contactor coil is energized, its normally open contact closes, shorting VD1, and the device's control power is mainly supplied by the AC conversion branch. When the input mains power is abnormal, the control contactor coil is not energized, its normally closed contact shorts VD2, and the device's control power comes from the DC conversion branch.

[0030] In Example 2, based on Example 1, temperature sensors TA are installed on each of the three phase lines of the three-phase AC power supply, and the coil TA, which is mutually inducted with the temperature sensor TA, is connected in series with the ammeter PA. A current transformer is installed on the line leading out of the inverter module to monitor the three-phase current. The positive output terminal of the electromagnetic interference suppression module is led out through switch K1 and connected to the RC filter module, with a resistor R0 connected in parallel across the two ends of switch K1. The output terminal of the inverter module is led out through switch KM2, and a pair of terminals on the line connecting the three-phase bridge rectifier circuit and the circuit breaker QF is directly connected through switches KM1 and KM2.

[0031] Example 3: Based on Example 1 or Example 2, the EMI differential mode inductor is set as follows: Figure 3 , Figure 4 , Figure 5 The encapsulated housing shown includes: a housing base 1, a mounting cavity 11 for installing an electromagnetic interference suppression module, a cover 2 embedded in the housing base 1, and a potting hole 21 and a wire hole 22 on the cover 2. After the electromagnetic interference suppression module is connected to the external circuit, the entire encapsulated housing is potted with thermally conductive adhesive through the potting hole 21.

[0032] Example 4, based on Example 1, incorporates a built-in dehumidifier within the industrial energy-saving cabinet. The dehumidifier utilizes existing technology; specific product models are not listed or elaborated upon here, as long as they effectively dehumidify the air within the cabinet. The dehumidifier operates as follows: its hot end dissipates heat via a fan. When the air with a high moisture content flows through the dehumidifier's evaporator, its temperature decreases, causing water droplets to condense on its surface. A water collection tray or guide pipe is located at the bottom of the evaporator to collect the condensate, allowing it to flow into a storage container or be directly directed outside the cabinet. This example employs semiconductor dehumidification based on the Peltier effect, reducing safety hazards associated with outdoor operation.

[0033] Example 5, based on Example 1, utilizes existing detection software for detection and control, such as... Figure 2 As shown, sampling lines are led out from the input and output terminals of the rectifier module and connected to the sampling module. The sampling module (DYJCB) adopts the existing electrical detection and control module. "DY" is a series identifier, and "JCB" can be understood as an abbreviation for "detection and control module". It is connected to the external host computer control system. When switching is required, the inverter module can act as a frequency converter to increase the output frequency to 50Hz (the standard power frequency). Through phase-locked loop technology, it tracks the phase, frequency, and amplitude of the grid voltage and adjusts the variable frequency output voltage to synchronize with it.

[0034] Working principle: This utility model discloses a universal energy-saving device for motors with strong compatibility, high energy saving rate, and strong stability. It has good equipment compatibility, excellent outdoor working stability, and stable electrical safety. While achieving traditional energy-saving applications, this utility model effectively suppresses the generation of its own harmonic content and improves the device's EMC anti-interference capability. It adopts a dual-power online redundancy design, which effectively reduces the failure problem caused by poor control power supply at a relatively low cost, and also solves the drawbacks of operation in humid environments.

[0035] Based on the preferred embodiments of this utility model, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the claims.

Claims

1. A universal energy-saving device for motors, comprising an energy-saving drive circuit installed in an industrial energy-saving cabinet and a control circuit interconnected with the energy-saving drive circuit: characterized in that, The power-saving drive circuit includes: a rectifier module, one end of which is connected to a three-phase AC power supply, and the other end of which outputs DC power through an electromagnetic interference suppression module. An RC filter module is connected in parallel to the output of the electromagnetic interference suppression module to output filtered DC power. The filtered DC power is then inverted by several sets of inverter modules and output to provide drive power to an external load. The control circuit includes: a bypass control circuit and a power-saving control circuit loop that achieve circuit switching control through an interlock module; The bypass control circuit includes: drawing a line voltage from two phase lines of the three-phase AC power supply as the line power source; the line power source is converted to DC power through an AC-DC conversion module. The power-saving control circuit includes: an electromagnetic interference suppression module that outputs DC power, which is then converted to DC power by a DC-DC converter.

2. The universal energy-saving device for motors according to claim 1, characterized in that: The input terminal of the AC / DC converter module is connected to the line power supply through switch BK1, and the output terminal of the AC / DC converter module is output through diode VD1. The input terminal of the DC-DC converter module is connected to the output terminal of the electromagnetic interference suppression module through fuse FU, and the output terminal of the DC-DC converter module is output through diode VD2.

3. The universal energy-saving device for motors according to claim 2, characterized in that: The interlock module includes: a relay KY, the mutual inductance coil of relay KY is connected in parallel at the input terminal of the AC-DC conversion module; the normally open switch of relay KY is connected in parallel across diode VD1; and the normally closed switch of relay KY is connected in parallel across diode VD2.

4. A universal energy-saving device for motors according to claim 3, characterized in that: The rectifier module includes a three-phase bridge rectifier circuit. The three input terminals of the three-phase bridge rectifier circuit are connected to the three phase lines of the three-phase AC power supply through the circuit breaker QF. The two output terminals of the three-phase bridge rectifier circuit are output through the electromagnetic interference suppression module.

5. A universal energy-saving device for motors according to claim 4, characterized in that: The RC filter module includes a series-connected RC parallel circuit one and an RC parallel circuit two. The RC parallel circuit one includes a resistor R1, a capacitor C1, a resistor R2, and a capacitor C2 connected in parallel. The RC parallel circuit two includes a resistor R3, a capacitor C3, a resistor R4, and a capacitor C4 connected in parallel.

6. A universal energy-saving device for motors according to claim 5, characterized in that: Each inverter module includes two sets of IGBT switching units connected in series. Each set of IGBT switching units has a freewheeling diode connected in parallel across its two ends. The output of the series node of the two sets of IGBT switching units in each inverter module is used as a drive power supply and connected to the external load.

7. A universal energy-saving device for motors according to claim 6, characterized in that: Temperature sensors TA are installed on the three phase lines of the three-phase AC power supply, and the coil TA that is mutually inducted with the temperature sensor TA is connected in series with the ammeter PA.

8. A universal energy-saving device for motors according to claim 7, characterized in that: Current transformers are installed on the lines leading out of the inverter module to monitor the three-phase current; And / or, the positive output terminal of the electromagnetic interference suppression module is led out through switch K1 and connected to the RC filter module.

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