CN1101071C - ups - Google Patents

Abstract

The invention relates to an uninterruptible power supply capable of outputting harmonic voltage and recovering energy, which is characterized by comprising the following components: a battery device; a DC/DC converter connected to the battery for converting the DC voltage of the battery into harmonic DC voltage; a inverter connected to the DC/DC converter; a relay device, which is respectively connected with the commercial power and the inverter to switch and select the power; a microcontroller connected with the inverter to control the voltage switching action; and the energy recovery charger is connected between the relay and the battery and is controlled by the ratio of the microcontroller to the direct current/direct current converter to determine whether to recover power to the battery device.

Description

ups

The present invention relates to an uninterruptible power supply, in particular to a simple DC/DC converter that converts the battery voltage into a harmonic output voltage, and uses an energy recovery charger to recycle unnecessary energy to the battery, thereby providing Off-line uninterruptible power supply with harmonic output and energy recovery for high-quality and high-efficiency power supply.

An uninterruptible power supply (UPS) is an AC power supply that can provide AC power instantaneously when the mains is abnormal. Among them, the offline UPS only passes the mains through its filter and directly connects to the output when the mains is normal. The terminal is used for the load connected to the output terminal of the UPS. When the mains power is abnormal (the voltage is too high or too low, etc.), refer to the simple structure of a UPS in Figure 4. The UPS converts the voltage of its internal battery 41 through a DC/DC converter (DC/DC converter) 42 into Higher DC voltage, and then use inverter 43 to convert this higher DC voltage into AC voltage for use by the load, and this AC voltage output is a square wave form, but for inductive loads (such as transformers, motors ), this kind of square wave output will cause load damage. Therefore, higher-level UPSs hope to provide harmonic output, but it must be achieved with extremely complex circuits, and relatively more energy must be consumed. Therefore, Therefore, how to provide an uninterruptible power supply with low energy consumption and output harmonics with a simple structure has become an urgent problem to be solved.

The purpose of the present invention is to provide an improved uninterruptible power supply, which can form a harmonic output voltage with a simple circuit structure, and can recover excess energy, so it can provide high-quality and high-efficiency power.

The purpose of the present invention is achieved like this:

An uninterruptible power supply characterized in that it includes:

a battery device for supplying DC voltage;

a DC/DC converter, the input of which is connected to the battery to convert the DC voltage of the battery into a DC voltage of a harmonic shape;

An inverter, whose input terminal is connected with a DC/DC converter to convert the output DC voltage of harmonic shape into a harmonic output voltage;

A relay device, the output terminals of which are respectively connected to the mains and the inverter, so as to switch and select the power provided by the output of the mains or the inverter;

A micro-controller, the output end of which is connected to the inverter, to control the voltage switching action of the inverter;

An energy recovery charger, the energy recovery charger is connected between the output terminal of the relay device and the battery device, and is controlled by the ratio of the reference signal output by the microcontroller to the feedback voltage output by the DC/DC converter to determine whether to recover power to the battery unit.

In the above uninterruptible power supply, wherein the DC/DC converter includes:

a DC/DC controller, which generates a PWM control signal according to the harmonic reference voltage generated by the microcontroller and the fed back harmonic-shaped DC voltage; and

A DC/DC transformer and switcher is controlled by the PWM control signal to convert the DC voltage of the battery into a harmonic DC voltage.

In the above uninterruptible power supply, wherein, the DC/DC controller is an adjustment pulse width modulator, according to the ratio of the reference voltage output by the microcontroller and the feedback voltage output by the DC/DC converter. Two sets of PWM control signals are generated to control the action of the DC/DC transformer and switcher, and one of the output terminals of the PWM control signal is connected to the energy recovery charger to control its action.

In the above uninterruptible power supply, wherein the energy recovery charger includes:

a charging switch and transformer, which selectively supplies power to the battery device with commercial power, and recovers excess energy from the uninterrupted power supply to the battery device, and

A charge controller, which is controlled by the harmonic-shaped DC voltage, the harmonic reference voltage and the PWM control signal, so that when the harmonic-shaped DC voltage is abnormally increased and the PWM control signal does not exist Control the charging switching and the work of the transformer for energy recovery.

In the above uninterruptible power supply, wherein the charging controller includes:

an error amplifier, used for comparing the DC voltage of the harmonic shape with the magnitude of the harmonic reference voltage;

a DC/DC PWM detector for detecting the presence of the PWM control signal; and

A charging PWM controller, which controls the charging switching and the operation of the transformer according to the comparison result of the error amplifier and the detection result of the DC/DC PWM detector.

Compared with the prior art, the uninterruptible power supply of the present invention has obvious advantages and positive effects due to the adoption of the above-mentioned technical scheme. From the above technical solutions, it can be seen that the uninterruptible power supply of the present invention can provide harmonic output voltage with a simple circuit structure, and can recover unnecessary energy, thereby providing high-quality and high-efficiency power.

Through the following description of an embodiment of the uninterruptible power supply of the present invention in conjunction with the accompanying drawings, the purpose, specific structural features and advantages of the present invention can be further explained. Among them, the attached figure is:

Fig. 1 is a structural block diagram of an uninterruptible power supply proposed according to the present invention.

Fig. 2 is a structural block diagram of an energy recovery charger in an uninterruptible power supply according to the present invention.

Fig. 3 is an electrical principle diagram of the uninterruptible power supply proposed according to the present invention.

Fig. 4 is a structural block diagram of an uninterruptible power supply in the prior art.

As shown in Figure 1, the uninterruptible power supply of the present invention mainly includes: components such as DC/DC converter 11, energy recovery charger 12, inverter 13, microcontroller 14, input filter 15, relay 16 and battery 17 . Wherein, the input filter 15 filters the mains power and then outputs power through the relay 16 when the mains power is normal. The relay 16 can also switch the power supply source when the mains power is abnormal.

In order to provide appropriate power when the mains power is abnormal, the DC/DC converter 11 converts the voltage of the battery 17 into a DC voltage of a harmonic shape, so that the inverter 13 can convert the DC voltage of this harmonic The voltage is directly switched to the output, so that the load terminal obtains a harmonic output, and no longer needs to be completed through complicated circuits. In order to achieve this purpose, the microcontroller 14 needs to send a harmonic reference signal, so that The DC/DC converter 11 follows this reference signal and adjusts its output to a harmonically shaped DC voltage for use by the inverter 13, and the DC/DC converter 11 is composed of a DC/DC controller 111 and a DC/DC controller 111. The DC transformer and the switcher 112 are formed, and the DC/DC controller 111 can be a regulating pulse width modulator (regulating pulse width modulator), which is based on the reference signal of the microcontroller 14 and the DC/DC transformer and The feedback voltage of the switcher 112 is used to generate two pulse width modulation signals (PWM1, PWM2) to control the DC/DC transformer and the switcher 112 to generate the required harmonic output.

In order to keep the UPS in a charging state and recover unnecessary excess energy when supplying power, the energy recovery charger 12 converts the AC voltage at the output terminal into the charging voltage of the battery when the mains power is normal, and when the mains power is abnormal and the UPS uses When the internal battery 17 converts energy output, the energy recovery charger 12 can provide the function of energy recovery. Please refer to Figure 1 for its working method. When the load of the UPS is an inductive load, because the output voltage and current have a phase difference The problem is that sometimes the output current will be fed back to the output terminal of the DC/DC converter 11, causing the output voltage to rise. At this time, even if the DC/DC controller 111 does not output the PWM signal, the voltage will rise. High and no longer like a harmonic voltage, so the energy recovery charger 12 must recover this excess unwanted energy to the battery 17 at this moment, and then provide it to the DC/DC converter 11 to improve the overall efficiency. The energy recovery charger 12 is mainly composed of a charging controller 121 and a charging switch and transformer 122. The feedback voltage and the PWM signal of the DC/DC controller 111 are used to control the charging switch and the transformer 122 to recover excess energy to the battery 17 . However, the action of energy recovery is not always possible, and the conditions for its activation must be: (1) the output has energy recharge, causing the DC/DC output voltage to rise; (2) when the DC/DC converter 11 has no PWM signal . Therefore, in order to detect these two conditions, please refer to the block diagram of the charging controller 121 in FIG. 2 , which includes an error amplifier 1211 and a DC/DC PWM detector 1212 to complete the aforementioned detection work. The error amplifier 1211 compares the output voltage of the DC/DC converter 11 with the harmonic reference signal of the microcontroller 14. When the output voltage rises abnormally, the output of the error amplifier 1211 becomes large to force a charging PWM controller 1213 to work. Perform energy recovery. The DC/DC PWM detector 1212 detects the PWM signal of the DC/DC converter 11. When a PWM signal is generated, it means that the DC/DC converter 11 is working. At this time, the DC/DC PWM detector 1212 The output enable (ENA) signal activates the charging PWM controller 1213 to close the charging switch and the charging action of the transformer 122; and when no PWM signal is generated, the output of the error amplifier 1211 increases, indicating that there is current recharging At this time, the enable (ENA) signal activates the charging PWM controller 1213 to make the charging switching and transformer 122 work, and recover excess energy.

Regarding the circuit structure aspect of the present invention, the microcontroller 14, the input filter 15, the relay 16 and the battery 17, etc. are all existing elements, and will not be described in detail again, and the inverter 13 can be formed by a switching transistor. The DC/DC converter 11 can be any circuit capable of DC conversion and switching, such as a flyback (Flyback) or push-pull (Push-pull) circuit structure, and the energy recovery charger 12 can be any circuit capable of The circuit that alternating current is converted into direct current, such as flyback (Flyback) or step-down (Buck) circuit structure, what Fig. 3 shows is an example of circuit structure of the present invention, and wherein, this inverter 13 is made of four groups by micro-control The DC/DC converter 11 is a push-pull (Push-pull) circuit structure, and the energy recovery charger 12 is a flyback (Flyback) circuit structure.

Claims (5)

1. uninterrupted power supply is characterized in that it comprises:

One cell apparatus is with the supply direct voltage;

One DC-DC converter, its input is connected with battery, is converted to the direct voltage of a harmonic wave shape with the direct voltage with battery;

One inverter, its input and DC-DC converter are converted to the direct voltage of the harmonic wave shape of its output the output voltage of one harmonic forms;

One relay-set, its output is connected with inverter with civil power respectively, selects electric power to be provided by civil power or inverter output to switch;

One microcontroller, its output is connected with inverter, in order to control the voltage change action of described inverter;

One energy recuperation charger, this energy recuperation charger is connected between relay-set output and the cell apparatus, and controlled by the reference signal of microcontroller output and the ratio of DC-DC converter reset voltage, whether decision reclaims electric power to cell apparatus.

2. uninterrupted power supply according to claim 1 is characterized in that: described DC to DC converter comprises:

One direct current/dc controller, it generates pwm control signal according to the direct voltage by this harmonic wave shape of harmonic reference voltage that this microcontroller generated and feedback; And

One direct current/direct current transformation and switch, it is converted to the direct voltage of a harmonic wave shape by this pwm control signal control with the direct voltage with battery.

3. uninterrupted power supply according to claim 1 and 2, it is characterized in that: described DC-DC controller is an adjustment pulse width modulation device, ratio according to the feedback voltage of the reference voltage of microcontroller output and DC-DC converter output produces two groups of PWM controlling signal, action with control DC-DC transformation and switch, wherein one group of PWM controlling signal output is to be connected to the energy recuperation charger, to control its action.

4. uninterrupted power supply according to claim 1 is characterized in that: described energy recuperation charger comprises:

One charging is switched and transformer, its be optionally with civil power to this cell apparatus power supply, and the excess energy of the supply of electric power of will not cutting off the power supply is recycled to this cell apparatus, and

One charge controller, it is controlled by the direct voltage of this harmonic wave shape, this harmonic reference voltage and this PWM controlling signal, switches the work of carrying out energy recuperation with transformer to control this charging when the undesired rising of the direct voltage of this harmonic wave shape and this PWM controlling signal do not exist.

5. uninterrupted power supply according to claim 4 is characterized in that: described charge controller comprises:

One error amplifier is in order to the relatively direct voltage of this harmonic wave shape and the size of this harmonic reference voltage;

One direct current/DC PWM detector is in order to survey the existence of this pwm control signal; And

One charging PWM controller, its result of detection according to the comparative result of this error amplifier and this DC-DC PWM detector control that this charging is switched and the work of transformer.

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